HK1153961B - Drive assembly suitable for use in a drug delivery device and drug delivery device - Google Patents

Description

Drive assembly suitable for use in a drug delivery device and drug delivery device

The present patent application claims priority from european patent application EP08009260.4 filed on day 5/20 in 208 and EP 08011676.7 filed on day 27 in 2008. The entire disclosures of these patent application documents are incorporated by reference into this application.

Technical Field

The present invention relates to a drive assembly suitable for use in a drug delivery device, preferably a pen-type injector, with which a plurality of pre-set doses of a drug product can be administered. In particular, the present invention relates to a drug delivery device wherein a user may activate the drug delivery device.

Background

Such drug delivery devices have application requirements where a person, i.e. a patient, who has not received formal medical training needs to administer an accurate and predetermined dose of a pharmaceutical product, such as heparin or insulin. In particular, such devices have application requirements where the pharmaceutical product is regularly administered over a short or long period of time.

These situations set some requirements for such a drug delivery device to meet. The device should be robust in construction yet easy to use in terms of component handling, user-comprehensible in its operation and delivery of the required dose of medicament. Dose setting should be convenient and clear. In the case where the device is disposable rather than reusable, the device should be inexpensive to manufacture and easy to handle (preferably suitable for recycling). To meet these requirements, the number of parts required to assemble the device and the number of types of materials from which the device is made should be kept to a minimum. In particular, a drive assembly for a drug delivery device should be provided which facilitates obtaining information about the number of doses of medicament dispensed from the drug delivery device, or the number of remaining doses of medicament in the drug delivery device for dispensing.

In EP1690561a 2a syringe is taught having a plunger that is pulled from the rear end of the syringe to set a dose. During the pulling back of the plunger, the sleeve is circumferentially indexed, with letters on the outside of the sleeve corresponding to each day of the week. As the plunger moves forward, the sleeve remains stationary. Therefore, the purpose of the device is not to provide information about the number of doses.

Disclosure of Invention

According to at least one aspect, a drive assembly is provided. The drive assembly may be a drive assembly for a drug delivery device.

According to at least one aspect, the drive assembly includes a housing. The housing preferably has a proximal end and a distal end. An axis may extend between the proximal end and the distal end.

According to at least one aspect, the drive assembly comprises at least one drive member. The drive member may be, for example, a drive sleeve. The drive member may be arranged on the proximal side. The drive member preferably transmits mechanical energy for operating the drive assembly. By means of the drive member, kinetic energy can be transferred to operate the drive assembly. The drive member may be configured to move along the axis. Preferably, the drive member is configured to move only along the axis. In other words, the drive member preferably does not rotate about the axis. Kinetic energy may be transferred by means of the drive member, for example by moving the drive member relative to the housing. The drug delivery device comprising the drive assembly may be driven by a push/pull mechanism, or any other mechanism known to the person skilled in the art. Rotation of the drive member, e.g. for setting a dose, is not required.

According to at least one aspect, the drive assembly comprises a piston rod. The piston rod is preferably adapted to be driven along the axis, in particular distally away from the proximal end. The piston rod may be driven along the axis by the drive member, in particular by kinetic energy provided by the drive member. The piston rod is movable along the axis relative to the housing, in particular distally away from the proximal end. The piston rod may drive the delivery of the medicament from the medicament cartridge.

According to at least one aspect, the drive assembly includes an indicator. The indicator may be adapted to provide information associated with or related to the position of the piston rod relative to the proximal and/or distal end of the housing. Preferably, the position is a position of the piston rod within the housing. The indicator may be adapted to provide clear information about the position of the piston rod. Preferably, the indicator is adapted to provide different information for different positions of the piston rod. In particular, the indicator may be adapted to provide information associated with the distance of the piston rod from the proximal end and/or the distal end. The indicator may be configured to provide information associated with a plurality of different distances of the piston rod from the proximal end, the provided information preferably being different for two different positions. The indicator is preferably configured to rotate about the axis. The indicator and the piston rod may be arranged on said axis.

According to at least one aspect, the indicator and the piston rod are configured to translate a relative movement of the indicator and the piston rod with respect to each other into a rotational movement of the indicator. The piston rod and the indicator may be coupled to each other, either directly or indirectly, for converting their relative movement into a rotational movement of the indicator.

The relative movement of the piston rod and the indicator, which is converted into a rotational movement of the indicator, may be or may comprise a relative movement along an axis and/or a relative rotational movement.

The relative movement of the indicator and the piston rod with respect to each other may comprise movement of the piston rod or the indicator with respect to the housing.

The rotational movement of the indicator may be or may comprise a rotational movement relative to the housing and/or a rotational movement relative to the piston rod.

According to at least one aspect, the indicator and the piston rod are configured to translate movement of the piston rod relative to the housing into rotational movement of the indicator. In this case, the indicator and the piston rod do not have to be moved axially relative to each other to achieve a rotational movement of the indicator. The piston rod and the indicator may be coupled to each other, directly or indirectly, for translating movement of the piston rod relative to the housing into rotational movement of the indicator.

The rotational movement of the indicator is preferably a rotational movement about the axis. Thus, the angle of rotation of the indicator may be an indication of the position of the piston rod relative to the proximal end and/or the distal end. The angle of rotation of the indicator may be directly related to the distance of the piston rod from the proximal end and/or the distal end.

The movement of the piston rod relative to the housing which is converted into a rotational movement of the indicator may be or may comprise a movement of the piston rod relative to the housing along the axis and/or a rotational movement of the piston rod relative to the housing.

The rotational movement of the indicator may be or may comprise a rotational movement relative to the housing and/or relative to the piston rod.

According to at least one aspect, the drive assembly is configured to move the piston rod unidirectionally along the axis. Preferably, the drive assembly is configured to move the piston rod unidirectionally with respect to the housing, in particular distally away from the proximal end, preferably only away from the proximal end. Of course, when the drive assembly is reset to the initial state, e.g. after a full dose of medicament has been dispensed from the cartridge and the cartridge has been replaced with a new cartridge, the piston rod may be allowed to move in the proximal direction.

According to at least one aspect, the drive assembly is configured to move the indicator in a unidirectional rotational motion. The unidirectional rotational movement may be a clockwise movement or a counterclockwise movement. Of course, rotational movement of the indicator in either direction may be permitted when the drive assembly is reset to the initial state.

According to at least one aspect, the drive assembly comprises a rotating member. The indicator may comprise a rotating member. The rotation member is preferably configured to translate a relative movement of the indicator and the piston rod with respect to each other and/or a relative movement of the piston rod with respect to the housing into a rotational movement of the indicator. The indicator may be coupled via the rotational member or permanently coupled to the piston rod. The coupling may be direct or indirect. Rotation of the rotary member advantageously results in rotational movement of the indicator. The indicator or an indicating part thereof and the rotary member may be of unitary construction or separate components. Of course, a unitary construction of the indicator and the rotary member is preferred for minimizing the number of parts of the drive assembly.

According to at least one aspect, the rotation member is at least partially arranged between the piston rod and the axis. At least a part of the rotation member or the rotation member, and preferably the indicator, may be arranged within the piston rod. This arrangement of the rotation member allows to advantageously implement the indicator within a drive assembly having a drive element arranged outside the piston rod, such as an element mechanically contacting the housing, e.g. by engaging the housing. Furthermore, the arrangement of the rotational member closer to the axis than the piston rod facilitates a compact design of the drive assembly. Furthermore, the freedom of the position of the indicator within the drive assembly is increased, since components of the rotary member may be arranged between the piston rod and said axis. Preferably, a component of a rotary member arranged within the piston rod is also arranged to contact the piston rod for translating movement of the piston rod relative to the housing into rotational movement of the indicator. Thus, the coupling between the rotation member and the piston rod may be achieved from within the piston rod via said rotation member, e.g. by the piston rod and said indicator engaging and/or mechanically interacting. An external feature on the outside of the rotational member, e.g. on the outer wall, may be arranged to mechanically interact with an internal feature provided within the piston rod, e.g. on the inner wall of the piston rod. If the rotary member or the indicator is arranged completely outside the piston rod, for example as an indicator sleeve surrounding the piston rod, it is necessary to have the indicator arranged close to the distal end of the housing, so that the piston rod travelling via the indicator can still be coupled to the indicator, even if the piston rod has been moved a significant distance in the distal direction. This situation may be avoided in view of the rotation member, since the rotation member may be configured to couple the piston rod and the indicator, whereas different indicator parts of the indicator may be used for providing (displaying) information.

According to at least one aspect, the indicator has an indicating surface, such as one or more indicating surfaces. The indicating surface is preferably provided with a plurality of indexing elements. The indexing elements are preferably discrete indexing elements. When the drive assembly is implemented in a drug delivery device, the indexing element may be adapted to provide information on the number of doses remaining in the drug delivery device and/or information on the number of doses dispensed from the device. The indexing elements may comprise single digits, numbers and/or letters. The letter P may be used to indicate, for example, that the initial dose is still available in the device. The letter D may be used to indicate that, for example, a primary dose has been dispensed. The single digit and/or number may indicate the number of doses already used and/or the number of doses remaining in the device.

The indication surface is preferably configured to be rotatable relative to the housing and/or the piston rod. The turning of the indicating surface may be achieved by a relative movement of the piston rod and the indicator with respect to each other and/or by a movement of said piston rod with respect to said housing which is converted into a rotational movement of the indicator. The indicating surface may be rotatable about the axis.

The indicator may include an indication location. If the indexing element is in the indicated position, the user knows that this particular indexing element provides relevant information associated with the current position of the piston rod. When the indicator is rotated, the first indexing element in the indicating position may be replaced by the second indexing element in the indicating position.

Preferably, the drive assembly is configured such that the at least one indexing element is visible from the outside of the drive assembly. Advantageously, the indexing element in the index position is at least visible from the outside. The indexing elements not in the index position may not be visible from the outside. The housing or the drive member may comprise a window, such as a recess or a transparent portion, for the indexing element to be visible from the outside, preferably only when the indexing element is in the indicating position.

During rotation of the indicator surface, different index elements may become visible through the window. The position of the window may for example define the pointing position of the pointer.

According to at least one aspect, the indicator is movable along the axis. The indicator may be movable relative to the housing and/or relative to the piston rod.

According to at least one aspect, the drive member is movable relative to the housing along the axis. The indicator may be coupled to the drive member such that the indicator follows axial movement of the drive member.

According to at least one aspect, the drive assembly is configured to translate movement of the indicator along the axis away from or towards the distal end of the housing into rotational movement of the indicator. Preferably, the drive member is movable along the axis and the indicator is coupled to the drive member such that the indicator follows axial movement of the drive member, for example proximal and/or distal movement of the drive member, such as movement of the drive member away from or towards the distal end of the housing. It is particularly preferred that the distally directed movement of the indicator is translated into a rotational movement of the indicator. Rotation of the indicator may be restricted or prevented during movement of the indicator away from the distal end. If the dose to be delivered is set by moving the drive member away from the distal end such that the indicator follows said movement, a rotational movement of the indicator may be prevented during setting. Thus, only a rotation of the indicator occurs when the indicator is moved distally, i.e. during dose dispensing. Thus, the indexing element in the indexing position is linked to the position of the piston rod relative to the proximal end, even if a dose has been set but not yet dispensed. The indicator may be rotated during dose dispensing.

According to at least one aspect, the drive assembly is configured to translate a distal movement of the piston rod along the axis away from the proximal end (in a distal direction) into a rotational movement of the indicator.

According to at least one aspect, the drive assembly is configured to restrict or prevent distal movement of the indicator distally along the axis relative to the housing and/or relative to the drive member. For example, the distal movement may be restrained or prevented by a mechanical stop of the drive assembly. The indicator, e.g. an indicating member of the indicator comprising an indicating surface, may mechanically contact the mechanical stop. The drive member or the housing may comprise the mechanical stop.

According to at least one aspect, the drive assembly is configured to restrict or prevent rotational movement of the piston rod relative to the housing. Preferably, the drive assembly is configured to move the piston rod only along the axis. Thus, a rotational movement of the piston rod relative to the housing may be avoided. This facilitates the manufacture of the drive assembly. Even if the indicator is rotatable about the axis relative to the housing because of the coupling between the indicator and the piston rod, the piston rod is preferably coupled to the housing to avoid rotation of the piston rod relative to the housing. The piston rod may be coupled to the housing, for example, by a spline coupling.

According to at least one aspect, the drive assembly is configured to move the piston rod, preferably distally, along the axis and to rotate the piston rod. In particular, the drive assembly may be configured to move the piston rod along the axis and simultaneously rotate the piston rod. The axis preferably serves as a rotational axis for the rotational movement of the piston rod. Thus, the piston rod may translate along and rotate about the axis relative to the housing. This movement may be achieved by a distal movement of the piston rod along said axis when a dose of medicament needs to be delivered from the medicament delivery device. The piston rod may mechanically interact with a piston of a medicament cartridge of a medicament delivery device.

According to at least one aspect, the indicator may be coupled or permanently coupled to the piston rod such that the coupling is configured to translate rotational movement of the piston rod into rotational movement of the indicator. Preferably, the rotational movement of the piston rod is converted into a rotational movement of equal rotational angle of the indicator. That is, if the piston rod is rotated through a certain angle, the indicator is rotated through the same angle. The indicator follows the rotational movement of the piston rod. The piston rod is of course additionally moved in the distal direction along the axis.

According to at least one aspect, the indicator may be coupled to the piston rod or may be coupled to the piston rod using a spline coupling. For example, the rotation member and the piston rod may be configured to be coupled or coupled using a spline connection. The rotating member may be a spline shaft, for example. This facilitates a rotational movement of the indicator and the piston rod through the same rotational angle.

According to at least one aspect, the indicator may be coupled or permanently coupled to the piston rod such that the coupling is configured to translate rotational movement of the piston rod into rotational movement of the indicator through different rotational angles. That is, if the piston rod is rotated through a first angle, the indicator is rotated through a second angle different from the first angle. Preferably, the indicator is rotated less, i.e. through a smaller angle, than the piston rod. The number of index elements provided on the indicating surface can be increased in this way.

According to at least one aspect, the indicator may be coupled or permanently coupled to the piston rod such that the coupling is configured for rotational movement of the piston rod and the indicator relative to each other.

According to at least one aspect, the drive assembly is configured such that the piston rod and the indicator rotate in the same direction or in different directions.

According to at least one aspect, the indicator may be coupled or permanently coupled to the piston rod such that the coupling is configured to prevent rotational movement of the piston rod relative to the indicator, preferably configured for pure translational movement of the piston rod relative to the indicator.

According to at least one aspect, the drive assembly is configured such that the indicator may be decoupled from the piston rod. Thus, the piston rod may be movable relative to the housing and/or relative to the piston rod along an axis in a region where there is no movement of the piston rod relative to the housing and/or relative movement of the indicator and the piston rod which is converted into rotational movement of the indicator. The rotation member may be arranged between the piston rod and the axis and/or within the region of the piston rod. In another region, movement of the piston rod translates into rotational movement of the indicator. The rotation member may be arranged between the piston rod and the axis, e.g. also within the region of the piston rod.

According to at least one aspect, at least one of the rotary member and the piston rod has a protrusion. Both the rotation member and the piston rod may have respective protrusions. Preferably, the protrusion is configured to mechanically interact with the other of the rotation member and the piston rod, e.g. by mechanical contact or engagement, for converting a relative movement of the piston rod and the rotation member and/or a movement of the piston rod with respect to the housing into a rotational movement of the rotation member with respect to the housing. The rotational movement of the rotating member of course results in a rotational movement of the indicator.

The protrusion may comprise one of a male thread, a rib, a knob, a pin, or a lug. The male thread may be a helical thread. The helical thread preferably extends along the axis.

The protrusion of the rotation member may be configured to mechanically interact with the protrusion of the piston rod, e.g. by mechanical contact or engagement of the protrusion.

According to at least one aspect, at least one of the rotary member and the piston rod has a recess. Preferably, the recess is configured to mechanically interact with the other of the rotational member and the piston rod, e.g. by mechanical contact or engagement, for converting a relative movement of the piston rod and the rotational member and/or a movement of the piston rod with respect to the housing into a rotational movement of the rotational member. The rotational movement of the rotating member of course results in a rotational movement of the indicator.

The recess may include one of a slot and a female thread. The thread may be a helical thread. The helical thread may extend along the axis.

According to at least one aspect, the protrusion of the rotation member or the protrusion of the piston rod engages the recess of the other of the rotation member and the piston rod.

According to at least one aspect, the rotation member has a section configured to threadedly engage the piston rod.

According to at least one aspect, the piston rod engages the housing. The piston rod may be threadably engaged with the housing. Whereby a rotational movement of the piston rod about the axis and/or a translational movement of the piston rod along the axis may be induced.

The pitch of the threads for threadedly engaging the rotary member and the piston rod may be different from the pitch of the threads for threadedly engaging the piston rod and the housing. Thereby, different rotation angles of the piston rod relative to the housing and of the indicator relative to the housing may be achieved.

According to at least one aspect, the indicator engages the housing or the drive member. The indicator may be threadably engaged with the housing or the drive member.

According to at least one aspect, the indicator comprises a plurality of indicating surfaces arranged side by side along the axis. The number of indexing elements of the indicator of a given size and arranged at a given distance from each other can be increased in this way.

The two indicating surfaces may be coupled to each other using a pedometer-like mechanism. For example, a 360 rotation of one indicating surface may result in a smaller rotation angle of the other indicating surface.

The drive assembly may be configured to replace the first indexing element of one indicating surface in the indicating position by the second indexing element of the other indicating surface in the indicating position by rotating the indicating surface. The threaded engagement of the indicator with the housing or with the drive member is particularly advantageous for this purpose. The indicating surface may be a partial thread.

For example, during rotation of the indicator, a first indicating surface visible from the outside through the window may be replaced by a second indicating surface that rotates (and translates) below the window.

According to at least one aspect, a drive assembly for use in a drug delivery device comprises:

a housing having a proximal end and a distal end;

a non-rotatable drive member;

the piston rod, which is engaged with the drive member, is preferably engaged by engagement means,

wherein:

a) the piston rod is not moved relative to the housing when the drive member is moved proximally relative to the housing;

b) upon distal movement of the drive member, the piston rod is rotated relative to the housing such that a force is transmitted in a longitudinal direction towards the distal end of the drug delivery device.

According to at least one aspect, there is provided a drive assembly for a drug delivery device, the drive assembly comprising:

a housing having a proximal end and a distal end;

a drive member located within the housing to move the drive member longitudinally;

a piston rod adapted to be operated by the housing and to transfer a force in a longitudinal direction to the distal end of the drug delivery device;

a rotation device releasably engaging the piston rod and being engaged to the drive member and to the housing,

it is characterized in that the preparation method is characterized in that,

a) when the drive member is moved proximally relative to the housing, the rotation means is moved proximally relative to the piston rod;

b) upon distal movement of the drive member, the rotation means moves distally and displaces the piston rod towards the distal end of the device.

The various aspects described above may be combined with each other and also with features and aspects described further below.

According to a particularly preferred embodiment, a drive assembly for a drug delivery device comprises:

a housing having a proximal end and a distal end;

an axis extending between the proximal end and the distal end;

at least one drive member;

a piston rod adapted to be driven by the drive member along the axis;

an indicator adapted to provide information about the position of the piston rod relative to the proximal end,

wherein

The indicator and the piston rod are configured to translate movement of the piston rod relative to the housing into rotational movement of the indicator relative to the housing.

Thus, via the angle of rotation of the indicator relative to the rotation of the housing, information about the position of the piston rod relative to the proximal end may be obtained. In particular, the angle of rotation may be directly linked to the position of the piston rod relative to the proximal end, and in particular to the position of the piston rod within the housing. Thus, the user may be provided with information about the number of doses remaining or the number of doses that have been dispensed in the medication delivery device, preferably in a medication cartridge of the medication delivery device comprising the drive assembly.

According to at least one aspect, there is provided a drug delivery device comprising a drive assembly as described above. The drug delivery device comprises a plurality of doses of a drug. The dose may be provided in a medicament cartridge of the device.

The indicator may be adapted to provide a discrete indication as to the number of doses available in the device or that have been dispensed from the device.

The drug delivery device may be a pen-type device. The drug delivery device may be a syringe type device. The drug delivery device may comprise a needle or may be a needle-free device.

The drug delivery device is preferably adapted to provide a fixed dose of the drug, i.e. a predefined amount of the drug during each delivery.

The piston rod may be configured to drive delivery of medicament from the medicament cartridge as the piston rod is moved distally along the axis.

The drive assembly described above and below may be configured such that the indicator is activated, i.e. rotated, when a dose is dispensed, e.g. from the drug delivery device by moving the drive member towards the distal end, preferably only during dose dispensing. Thus, rotational movement of the indicator may be restricted or prevented when setting a dose, e.g. by moving the drive member away from the distal end. Thus, the indicator may still have an indexing element in the indicating position indicating the current position of the piston rod after dose setting, i.e. the correct indexing element is in the indicating position. If the indicator is rotated during dose setting, the indexing element indicating the position of the piston rod after a dose has been set has been dispensed may be brought into the indicating position, i.e. an incorrect indexing element may be in the indicating position. By preventing or restricting the rotational movement of the indicator during dose setting, for example by means of a detent element, an incorrect indexing element can be prevented from being in the indicating position.

At least one other aspect relates to the use of a drug delivery device as described above for dispensing a drug product, preferably for dispensing a drug formulation (e.g., solution, suspension, etc.). The pharmaceutical product or pharmaceutical formulation may comprise an active compound selected from the group consisting of: insulin, growth hormone, small molecular weight heparin, their analogs and their derivatives.

The term "drug delivery device" should preferably be understood as meaning single-dose or multi-dose, or preset dose or predefined, disposable or reusable devices designed to dispense a user-selected or predetermined dose of a pharmaceutical product, such as insulin, growth hormone, small molecular weight heparin, their analogues and/or derivatives, etc., preferably a plurality of predetermined doses. The device may be of any shape, for example of the box type or of the pen type. Dose delivery may be achieved by a mechanical (optionally manual) drive mechanism or an electrical drive mechanism or an energy-storing drive mechanism such as a spring or the like. Dose setting may be achieved by a manual mechanism or an electronic mechanism. Furthermore, the device may contain components designed to monitor physiological characteristics such as blood glucose levels and the like. Further, the device may include a syringe, or may be a syringe-less device. In particular, the term "drug delivery device" should preferably be understood as a disposable, needle-based pen-type device providing a plurality of predetermined doses, having mechanical and manual dose delivery and dose setting mechanisms, which is designed to be used by persons not receiving formal medical training, such as patients. Preferably, the drug delivery device is of the syringe type.

The term "housing" should preferably be understood as any outer housing ("main housing", "body", "housing") or inner housing ("insert", "inner body"), e.g. with a unidirectional axial coupling to prevent proximal movement of the specific component. The housing may be designed to allow safe, correct and comfortable operation of the drug delivery device or any mechanism thereof. Typically, the housing is designed to house, secure, protect, guide and/or engage any internal components of the drug delivery device (e.g., drive assembly, cartridge, plunger, piston rod) by limiting exposure to contaminants such as liquid, dust, dirt, etc. In general, the housing may be a single or multi-part component, tubular or non-tubular. Typically, the outer housing may be used to house a cartridge from which a number of doses of a pharmaceutical product may be dispensed. Preferably, the outer housing is provided with a plurality of maximum dose stops adapted to be abutted by axial stops provided on the drive member. The piston rod may be coupled to the housing or may be coupled to the housing.

The term "drive assembly" should preferably be understood as a part of the medicament delivery device to which the medicament cartridge may be coupled or (permanently) coupled. The drive assembly may thus comprise an indicator, a housing and/or the piston rod. Furthermore, other elements may be present in the drive assembly, such as mechanical supports, e.g. the other elements described above and below. The elements of the drive assembly may be formed as described above and below.

The term "engage" should preferably be understood as an interlocking of two or more components of the drive assembly/drug delivery device, such as splines, threads or a meshed teeth connection, preferably the meshed teeth of said components.

The term "drive member" should preferably be understood as any component adapted to operate through/within the housing, which is designed to transfer axial movement, e.g. from an actuation means, to the piston rod through/within the medicament delivery device. In a preferred embodiment, the drive member additionally releasably engages the piston rod. The drive member may be of unitary or multipart construction.

The term "piston rod" should preferably be understood as a component adapted to operate through/within the housing, designed to transfer axial movement through/within the drug delivery device, preferably from the drive member to the piston of the cartridge, e.g. for the purpose of expelling/dispensing an injectable product from the cartridge. The piston rod may or may not be flexible. The piston rod may be a simple rod, lead screw, rack and pinion system, worm gear system, or the like. The term "piston rod" should further preferably be understood as a component having a circular or non-circular cross-section. The piston rod may be made of any suitable material known to those skilled in the art and may be of one-piece or multi-part construction. The piston rod may include a series of one or more sets of longitudinally spaced ribs and/or recesses. The piston rod may comprise a male or female thread. A male or female thread may be arranged on the outside of the piston rod and/or inside the piston rod.

The term "rotation means" should preferably be understood as any rotating component that transfers force and/or motion from the drive member to the piston rod. It may be made of any suitable material known to those skilled in the art and may be made in a single or multi-part construction. In a preferred embodiment, the rotating means may be a gear member, more preferably a spur gear.

The term "gearing" should preferably be understood as a gear wheel used in conjunction with a rack and/or another gearing to transmit force and/or motion. In a preferred embodiment, the gear means may be a spur gear. In another preferred embodiment, the term "gearing" refers to a gear wheel mounted within a carrier.

The term "rack" should preferably be understood as any component having a linear array of teeth in the form of ribs and/or recesses and/or gears. In a preferred embodiment, the rack is located within the housing and the other rack is located within the drive member. In a further preferred embodiment, one and/or both, more preferably one rack on the housing or the drive member is flexible and/or pivots on and/or moves along one or more axes, more preferably one axis.

The "distal end" of the device or a component of the device, for example the "distal end" of the housing, should preferably be understood as the end that is to be disposed closest to or disposed closest to the dispensing end of the device.

The "proximal end" of the device or a component of the device, for example the "proximal end" of the housing, should preferably be understood as the end which is to be arranged furthest away or is arranged furthest away from the dispensing end of the device.

The term "helical thread" should preferably be understood as a complete thread or a partial thread, e.g. cylindrical helical ribs/grooves, on an inner and/or outer surface of a component of the medicament delivery device, such as e.g. a piston rod, a housing, a drive member or an indicator. The thread preferably has a substantially triangular or square or rounded cross-section. The cross-section may be designed to allow continuous free rotation and/or axial movement between the components. Optionally, the thread may be further designed to prevent rotational movement and/or axial movement of the particular component in one direction, e.g. in an axial direction and/or a rotational direction about said axis.

Drawings

Without any limitation, for example, without any limitation to the scope of the claims, preferred embodiments will be described below with reference to the accompanying drawings, in which:

FIG. 1 shows a diagonal cross-sectional view of a first embodiment of a drive assembly;

FIG. 1A shows a cross-sectional view of a first embodiment of a drive assembly;

FIG. 2 shows a diagonal cross-sectional view of a second embodiment of the drive assembly;

FIG. 2A shows a second embodiment with the piston rod moved away from the proximal end to a first position;

FIG. 2B shows a second embodiment with the piston rod moved away from the first position and the proximal end to a second position;

FIG. 3 shows a diagonal cross-sectional view of a third embodiment of the drive assembly;

FIG. 4 shows a diagonal cross-sectional view of a fourth embodiment of the drive assembly;

FIG. 5 shows a diagonal cross-sectional view of a fifth embodiment of the drive assembly;

FIG. 6 shows a diagonal cross-sectional view of a sixth embodiment of the drive assembly;

fig. 6A shows a cross-sectional view of a sixth embodiment with the piston rod in a different position relative to the rotational member;

FIG. 7 shows a diagonal cross-sectional view of a seventh embodiment of the drive assembly;

FIG. 8 shows a diagonal cross-sectional view of an eighth embodiment of the drive assembly;

FIG. 9 shows a diagonal cross-sectional view of a ninth embodiment of the drive assembly;

fig. 10 schematically shows the relative movement of the piston rod and the indicator with respect to each other for a situation similar to the ninth embodiment;

FIG. 11 shows a cross-sectional view of a tenth embodiment of the drive assembly in a first, starting position;

fig. 11A shows a cross-sectional view of the tenth embodiment in a second position, e.g. a dose set position;

fig. 11B shows a cross-sectional view of the tenth embodiment in a third position, e.g. a dose delivery position;

FIG. 11C shows a cross-sectional view of the tenth embodiment in a third position, e.g., an indicator rotated position;

fig. 12 schematically shows the relative movement of the piston rod and the indicator with respect to each other for a situation similar to the tenth embodiment;

figure 13 shows an oblique cross-sectional view of the first embodiment of the medicament delivery device;

figure 13A shows a side view of the first embodiment of the medicament delivery device in a first position, e.g. a cartridge filled position;

fig. 13B shows a cross-sectional view of the first embodiment of the medicament delivery device in a second position, e.g. a first dose setting position;

fig. 13C shows a sectional view of the first embodiment of the medicament delivery device in a third position, e.g. a first dose dispensing position;

figure 13D shows a cross-sectional view of the first embodiment of the medicament delivery device in a fourth position, e.g. a final dose setting position;

figure 13E shows a cross-sectional view of the first embodiment of the medicament delivery device in a fifth position, e.g. a final dose dispensing position;

figure 14 shows an oblique cross-sectional view of a second embodiment of a medication delivery device;

figure 14A shows a side view of the second embodiment of the medicament delivery device in a first position, e.g. a cartridge filled position;

fig. 14B shows a cross-sectional view of the second embodiment of the medicament delivery device in a second position, e.g. a first dose setting position;

fig. 14C shows a sectional view of the second embodiment of the medicament delivery device in a third position, e.g. a first dose dispensing position;

figure 14D shows a cross-sectional view of the second embodiment of the medicament delivery device in a fourth position, e.g. a final dose setting position;

figure 14E shows a cross-sectional view of the second embodiment of the medicament delivery device in a fifth position, e.g. a final dose dispensing position;

in the drawings, like elements, homologous elements and elements acting in the same way are provided with the same reference numerals.

Detailed Description

Fig. 1 shows a diagonal cross-sectional view of a first embodiment of a drive assembly. Fig. 1A shows a cross-sectional view of a first embodiment of a drive assembly.

The drive assembly 1 according to fig. 1 and 1A comprises a housing 2. The housing has a proximal end 3 and a distal end 4. Axis a extends between proximal end 3 and distal end 4. The drive assembly 1 comprises an indicator 5. Furthermore, the drive assembly 1 has a piston rod 6. The indicator 5 and the piston rod 6 are located within the housing 2. Furthermore, an indicator 5 and a piston rod 6 are arranged on said axis. Thus, the axis a may extend through the piston rod 6 and the indicator 5. The housing 2 may have a tubular shape. The rotating member 7 may be formed in a shaft shape.

The drive assembly 1 comprises a rotary member 7. The rotation member 7 is arranged inside the housing 2. The main (longitudinal) direction of the span of the piston rod 6 and/or the rotational member 7 is aligned along the axis a. The rotation member 7 and the indicator 5 may form separate elements or form an integral body, i.e. the rotation member 7 may be part of the indicator 5. The indicator 5, the piston rod 6 and/or the rotation member 7 may be held in the housing 2. The piston rod 6 is movable in a distal direction along the axis a relative to the housing 2. The indicator 5 is rotatable relative to the housing 2 about an axis a. The axial movement of the indicator 5 is restricted. Preferably, the axial movement in the distal direction and/or in the proximal direction is constrained.

A partial region of the rotary member 7 extends axially into the piston rod 6. In this region, the rotary member 7 is arranged between the piston rod 6 and the axis a. The rotation member 7 may extend from outside the piston rod into the piston rod 6.

The indicator 5, the piston rod 6 and/or the rotary member 7 may be fixed against displacement in radial direction with respect to the axis a. The drive assembly 1 comprises a mechanical support 8. The mechanical support may be configured to fix the indicator 5, the piston rod 6 and/or the rotational member 7 against displacement in the radial direction.

The mechanical support 8 is preferably configured to provide mechanical support for the piston rod 6. The mechanical support 8 also provides mechanical support for the rotating member 7. Alternatively, a separate mechanical support may be used to support the rotary member 7 (not explicitly shown). The piston rod 6 may be in mechanical contact with the mechanical support 8. The mechanical support 8 may be formed integrally with the housing 2 or as a separate element connected to the housing, in particular to the inner wall thereof. The mechanical support 8 may protrude from the inner wall of the housing 2.

The piston rod 6 may extend through a mechanical support 8, e.g. through an opening 9 thereof, e.g. a cut-out or a hole.

The piston rod 6 is preferably coupled to the housing 2 for non-rotational movement of the piston rod relative to the housing. The piston rod may be coupled to the housing, for example by means of a splined connection. The coupling preventing rotational movement of the piston rod 6 relative to the housing 2 may be realized by means of a mechanical support 8. The opening 9 in the mechanical support 8 may be hollowed out in order to non-rotatably couple the piston rod 6 to the housing 2. The openings may have, for example, a rectangular or square cross-section for this purpose.

The cross section of the opening 9 and the cross section of the piston rod 6 may correspond to each other when viewed in the axial direction a. The piston rod may for example have a rectangular or square cross-section. The rotation of the piston rod is thus prevented by the opening 9, which opening 9 inhibits or prevents the rotational movement of the piston rod 6.

The piston rod 6 is arranged to be movable along the axis a and in particular within the housing 2. Preferably, the piston rod 6 is arranged for purely translational movement along said axis. Furthermore, the drive assembly 1 is preferably configured to move the piston rod in one direction in a distal direction along the axis, away from the proximal end 3 of the housing 2.

The indicator 5 is fixed against axial movement relative to the housing 2 and/or the piston rod 6. Thus, the piston rod 6 may be moved in a distal direction relative to the indicator 5 and the housing 2, which indicator may not be moved axially relative to the housing.

The drive assembly 1 comprises a mechanical stop 10. The mechanical stop 10 may protrude from the inner wall of the housing. The mechanical stop 10 is preferably configured to prevent movement of the indicator away from the proximal end 3 and/or towards the distal end 4. Preferably, the drive assembly 1 comprises an additional mechanical stop 11. The mechanical stop 11 may be implemented in accordance with the mechanical stop 10. The mechanical stop 11 is preferably configured to prevent proximal movement of the indicator away from the distal end 4. The mechanical stop 10 and/or 11 may have an annular shape.

The indicator 5 comprises an indicating surface 13. The indicator 5 comprises an indicating member 12. The indicating surface 13 may be a surface of the indicating member 12. The indicating member 12 may be formed in a disc shape, for example. The mechanical stops 10 and 11 may for example cooperate to form a recess surrounding the mechanical indicator member 12. The rotation member 7 is preferably torque proof connected to the indication surface 13 and/or the indication member 12. The indicator part 12 may protrude radially with respect to the rotary member, which may be shaft-shaped.

The indicating surface 13 is provided with a plurality of indexing elements 14, preferably discrete markings. The indexing element 14 may comprise a single digit, i.e., 0.. 9; numbers, i.e., numbers greater than 9; and/or one or more letters.

The indexing element 14 may be adapted to provide information associated with the number of doses of medicament remaining in or dispensed from a medicament delivery device comprising a drive assembly and a cartridge preferably containing medicament. Preferably, the indexing element 14 is adapted to provide information relating to the number of remaining medicament doses in or dispensed from a medicament delivery device comprising a drive assembly.

At least one index element 14 arranged in the index position can be seen from outside the drive assembly 1. For this purpose, a window 15 is provided, for example a transparent part of the housing 2 or an opening of the housing 2, so that the index element (shown as single digit "1" in fig. 1) in the index position can be seen through the window from the outside. The indexing elements not in the index position may not be visible from the outside.

The rotation member 7 may run from outside the piston rod 6 to inside the piston rod through an opening 16 of the piston rod, which opening 16 is for example a circular opening, such as a hole. The opening 16 is preferably arranged on the side of the piston rod 16 facing the proximal end 3.

The piston rod 6 and the indicator 5 are coupled to each other via the rotation member 7 such that a movement of the piston rod 6 along the axis, preferably a unidirectional movement (in distal direction) away from the proximal end 3, causes a rotation of the rotation member 7 and thus a rotation of the indicator 5, in particular of the indicating surface 13. Preferably, the coupling is configured for rotating the indicating surface 13 to rotate the indexing element 14 to the indicating position previously occupied by a different indexing element. The rotary member 7 and the piston rod 6 are in tight engagement in this embodiment.

The rotation of the rotation member 7 causes the indicator 5, in particular the indicating surface 13 thereof, to rotate. The rotary member is preferably fixed against rotation relative to the indicator 5.

In order to achieve a coupling between the rotation member 7 and the piston rod 6, the rotation member 7 comprises a recess 17. The recess 15 may be provided on the outer surface of the rotation member. The recess 17 may be a thread, for example a helical thread running helically about the axis a. The piston rod 6 preferably comprises a protrusion or a plurality of protrusions 18. The respective protrusions 18 may be provided on the inner surface of the piston rod. The respective protrusion 18 may be provided on the side of the piston rod 6 facing the proximal end 3, preferably in the opening 16. The protrusion 18 or protrusions 18 may form a (single) thread, a part of a thread, a ball shank or a pin. Each protrusion 18 engages a recess 17 to engage the piston rod 6 and the rotational member 7 with each other.

The indicator member 12 and/or the indicator surface 13 may be freely positioned within the drive assembly, taking into account that a part of the rotational member 7 is arranged within the piston rod, in particular between the axes a of the piston rod 6. It is not necessary that the indication surface 13 is arranged close to the distal end 4, as the coupling between the indicator 5 and the piston rod 6 is realized via the rotation member 7. Arranging the indexing surface close to the proximal end 3 may improve the visibility of the indexing element 14 during operation of the drive assembly, e.g. during dose dispensing.

If the drive assembly preferably comprises a drive member (not explicitly shown) for forcing the piston rod 6 to move away from the proximal end 3, the protrusion 18 engages a side wall of the recess 17 arranged on the side of the recess 17 facing away from the proximal end 3. By means of this mechanical contact of the protrusion 18 and the piston rod 6, the rotation member 7 is guided along the thread and caused to rotate. The direction of rotation, clockwise or counterclockwise, is determined by the thread of the rotary member 7. As the piston rod 6 travels away from the proximal end 3, the indicator 5 and in particular the indicating surface 13 rotates so that the index element 14 (e.g. single digit "1") visible through the window in fig. 1 is replaced by the next index element 14 (e.g. single digit "2") in the column. Due to the force moving the piston rod 6 away from the proximal end 3, the indication member 12 is pressed against the mechanical stop 10. The mechanical stop 10 prevents distal movement of the indicator 5. The rotation of the piston rod 6 is prevented by the inner wall of the opening 9.

For setting a dose, the drive member may be moved in a proximal direction along said axis, e.g. away from the housing 2. The piston rod 6 does not move during setting.

The indicator 5 does not move during the setting process. For delivering a dose (dose dispensing), the drive member may be moved in a distal direction, e.g. towards the housing 2. The movement of the drive member transmits a force to the piston rod 6, which force the piston rod 6 is subjected to moves in the distal direction. A piston rod 6 coupled to the indicator 5 is moved distally causing the indicator 5 to rotate. Thus, movement of the piston rod along the axis translates into rotational movement of the indicator. The piston rod 6 may drive a piston of a medicament cartridge (not explicitly shown) in a distal direction resulting in a dose of medicament being dispensed from the cartridge.

The angle of rotation of the indicator 5 and in particular of its indicating surface 13 provides information about the distance the piston rod has traveled away from the proximal end. Movement of the piston rod away from the proximal end may cause a dose of medicament to be dispensed from the medicament delivery device. The angle of rotation may be directly related to the distance of the piston rod 6 from the proximal end 3. Thus, the indicator 5 may provide information directly related to the position of the piston rod relative to the proximal end 3.

Preferably, the drive assembly 1 is configured such that the piston rod 6 can only be moved distally away from the proximal end 3. When resetting the medication delivery device comprising the drive mechanism, proximal movement of the piston rod 6 is only allowed, for example before or after exchanging a used medication cartridge for another medication cartridge, preferably for a non-used medication cartridge.

Preferably, the indicator 5 is configured to rotate in only one direction, i.e. clockwise or counter-clockwise, when viewed from the same side of the indicator. The indicator may be configured such that it can be rotated in the other rotational direction only during resetting of the device, for example before or after a used medicament cartridge is exchanged for another medicament cartridge, preferably for an unused medicament cartridge.

The drive assembly as described above may be conveniently implemented in a drug delivery device comprising a piston rod, as only a few additional or modified elements are required.

Of course, as an alternative to the situation depicted in fig. 1, the piston rod 6 may comprise a recess, such as a slot or a female thread, and the rotation member 7 may comprise a protrusion, such as a male thread, for coupling the piston rod and the rotation member to each other.

The amount of rotation of the indicator 5 at a given distance of piston rod movement is:

the distance may correspond to a fixed dose dispensed from the drug delivery device;

it can be adjusted by appropriate choice of the thread pitch of the rotating member 7.

As shown in fig. 1 and 1A, if the piston rod is moved and coupled to the rotating member, the indicator is rotated in each case. This is because the helical thread runs continuously obliquely with respect to the axis a.

Fig. 2 shows a diagonal cross-sectional view of a second embodiment of the drive assembly 1. Fig. 2A shows a second embodiment with the piston rod moved distally away from the proximal end to a first position. Fig. 2B shows a second embodiment with the piston rod moved distally away from the first position and away from the proximal end to a second position. This embodiment substantially corresponds to the embodiment described with reference to fig. 1 and 1A.

Unlike the latter embodiment, the indicator 5 and the piston rod 6 are coupled to each other such that the coupling is configured such that for a given range of movement of the piston rod 6 along the axis a, the rotational movement of the indicator is decoupled from the movement of the piston rod along the axis. Within this range of motion, the rotation member 7 is also arranged within the piston rod 6.

To this end, the recess 17 comprises a zone 19 running parallel to the axis a. Thus, when the projection 18 runs in the area 19, no rotational movement of the rotary member 7 and no rotational movement of the indicator 5 is caused. On the side of the region 19 facing the distal end 4, a region 20 of the recess 17 can be arranged, which region 20 runs obliquely with respect to the axis. On the side of the zone 19 facing the proximal end 3, a zone 21 of the notch 17 is arranged, the notch 17 running obliquely with respect to the axis a in the zone 21. Region 19 may be disposed between regions 20 and 21. The region 20 and/or the region 21 may be (helical) threaded.

Of course, instead of the recess 17, a projection may be used, and instead of the projection 18, a recess may be used.

In the regions 20 and 21, the recess 17 runs obliquely with respect to the axis a, the indicator 5 rotating when the protrusion 18 engages said regions of the recess 17 and the piston rod 6 is moved away from the proximal end 3. The indicator does not rotate when the projection 18 travels along the area 19, for example as a result of further actuation of the drive assembly (e.g. by setting and dispensing a further dose). As the protrusion 18 moves along the proximal end region 21, the indicating surface 13 rotates. The indexing element 14 in the indexing position changes, for example, from the letter "P" indicating that a first dose is available to the letter "D" indicating that a dose has been dispensed from the device. When the projection 18 moves along the distal end region 20, the indicating surface 13 rotates again. The last number of doses, e.g. 3 doses, remaining in the drug delivery device may be counted down by rotating the indicator, which is caused by the engagement of the protrusion 18 with the distal end region 20.

In such an embodiment, the number of indexing elements provided on the indicating surface 13 may be reduced, as one indexing element, e.g. "D", may stay in the indicating position for more than one dose dispensing process. The user is still able to obtain information when a new medicament delivery device or a new filled medicament cartridge is required which can be operated with the drive assembly.

Compared to the first embodiment, a region or regions of the (helical) thread formed on the rotational member 7 may be replaced by regions running parallel to the axis a, such that the indicator does not rotate when the rotational member is coupled to the piston rod in said regions running parallel to the axis a.

Fig. 3 shows a diagonal cross-sectional view of a third embodiment of the drive assembly 1. The third embodiment substantially corresponds to the embodiment described with reference to fig. 1 and 1A.

In contrast thereto, the drive assembly 1 according to the third embodiment comprises a plurality of indexing surfaces, arranged side by side along the axis a. For example, the indicator 5 comprises two indicating surfaces 13 and 22. These indicating surfaces may each be provided with a plurality of indexing elements 14. The indicating surfaces 13 and 22 may not be rotatable relative to each other.

In this embodiment, the indicator 5, in particular its indicating member 12 comprising indicating surfaces 13 and 22, is screw-coupled to the housing 2. Preferably, the indicator 5 is threadedly engaged with the housing 2. The housing 2 may comprise (helical) threads 23 engaging (helical) threads 24 of the indication member 12.

If the indicator 5 is rotated, the indicating surface 22 can be rotated to the indicating position and replace the indicating surface 13 in that position. That is, the indication surface 13 may be rotatably distanced from the window, while the indication surface 22 may be moved under the window, so that one or more index elements arranged on the indication surface 22 become visible from the outside.

The indicator 5 may be fixed against distal movement relative to the housing, e.g. against proximal movement away, as shown in fig. 3. Proximal movement of the indicator 5 relative to the housing may be permitted.

The number of indexing elements can be increased in this way while keeping the indexing element size and indexing element distance of the indexing surface constant. More than one figure of indexing elements may be used.

Thus, by turning the indicator, the indicating surface 23, which is not visible from the outside as shown in fig. 3, can be rotated to be visible from the outside, while the piston rod is moved distally away from the proximal end 3.

Due to the coupling of the piston rod 6 and the indicator 5, the indicator 5 may rotate and move in the proximal direction with respect to the housing, thereby rotating and translating the indicating surface 22 below the window 15. Rotational movement of the indicator 5 may thus be translated into proximal movement of the indicator 5 along axis a. The distal movement of the indicator 5 is preferably restrained by a mechanical stop 10. The proximal movement of the indicator 5 is preferably restricted by a mechanical stop 11. The indicating surfaces 13 and 23 may be part threads.

Of course, according to this embodiment or the embodiments to be described, the indicator 5 with more than one indicating surface may be implemented in other drive assemblies described above and below.

Fig. 4 shows a diagonal cross-sectional view of a fourth embodiment of the drive assembly 1. The drive assembly shown in fig. 4 substantially corresponds to the drive assembly described with reference to fig. 3.

In contrast thereto, the indicator 5 comprises two indicating members 12 and 25, which are rotatable relative to each other. The indicating member 12 may comprise an indicating surface 13. The indicating member 25 may comprise an indicating surface 22. The indicating surfaces 13 and 22 are visible from the outside through the window 15.

The indicating surfaces 22 and 13 may rotate relative to each other. The indicating members 12 and 25 may be coupled to each other via a (similar) pedometer mechanism. Rotation of the indicator member 12 by a predetermined angle, for example about 360 ° throughout the figure, relative to the indicator member 25 may result in rotation of the indicator member 25 by an angle preferably less than about the predetermined angle to rotate the next indexing element 14 of the indicator surface 22 to the indicating position.

In this way, the number of states that can be indicated is significantly increased, since there are different combinations of indexing elements on the indicating surface 22 and indexing elements on the indicating surface 13. In particular, it may be convenient to display numbers greater than one digit, for example from 00 to 99. The indicating surface 22 may display a tens digit while the indicating surface 13 displays a unit digit.

Fig. 5 shows a diagonal cross-sectional view of a fifth embodiment of the drive assembly 1. The drive assembly according to fig. 5 substantially corresponds to the drive assembly described with reference to fig. 1 and 1A.

In contrast to the latter embodiment, the drive assembly according to fig. 5 is configured to move the piston rod 6 along the axis a and to rotate relative to the housing 2 about the axial direction a. The piston rod 6 is threadedly coupled to the housing 2. Preferably, the piston rod 6 is threadedly engaged with the housing 2.

The outer wall 26 of the piston rod 6 may comprise a (helical) thread 27 (male or female thread) engaging a thread 28 (female or male thread, respectively) provided in the housing 2. Threads 28 and/or 27 may be partial threads or full threads.

The mechanical support 8 may comprise a thread 28, for example. The rotary member 7 is coupled to the piston rod 6 by a splined connection. In particular, the rotation member 7 follows the rotation of the piston rod. Thus, the indicator 5 is rotated by an amount, e.g. an angle, equal to the amount of rotation of the piston rod 6. In particular, in this embodiment, a rotational movement of the piston rod 6 relative to the housing is converted into a rotational movement of the indicator 5 relative to the housing 2.

Fig. 6 shows a diagonal cross-sectional view of a sixth embodiment of the drive assembly 1. Fig. 6A shows a sectional view of a sixth embodiment, where the piston rod is in a different position with respect to the rotational member. This embodiment substantially corresponds to the embodiment described with reference to fig. 5. In particular, the piston rod 6 rotates and translates distally along the axis a away from the proximal end 3.

In contrast to the embodiment described with reference to fig. 5, the indicator 5 is decoupled from the movement of the piston rod 6 along the axis in a certain region. That is, in this region, the piston rod 6 may move along the axis a and along the rotation member 7 without causing the indicator 5 to rotate. In other words, the piston rod 6 may be moved distally along the axis a relative to the indicator 5 without interacting with the rotation member 7. In particular, if the piston rod and the indicator are decoupled, the piston rod 6 and the rotary member 7 do not mechanically interact. Preferably, in said decoupling region, there is no mechanical coupling between the piston rod 6 and the indicator 5.

The piston rod 6 decoupled from the rotary member 7 is shown in fig. 6A. The piston rod 6 can rotate and translate independently of the indicator 5. Without causing the indicator 5 to rotate. When setting a dose and dispensing a medicament from such a medicament delivery device comprising a drive assembly, the indicator 5 does not rotate relative to the housing 2 when the piston rod 6 is moved over a certain area of the rotational member 7. A drive member of a drive assembly (not explicitly shown) may be moved in a proximal direction away from the housing for setting a dose and in a distal direction towards the housing for dispensing a dose.

For coupling the piston rod 6 and the indicator 5, the piston rod 6 preferably comprises one or more protrusions 29, such as pegs, knobs, lugs or pins. The rotation member 7 may comprise one or more protrusions 30.

The protrusion 29 may protrude from the inner wall of the piston rod 6. The projection 29 extends along an axis corresponding to the section within which rotation of the indicator is desired. The projections 29 may be splined features, such as ribs, extending along the axis a. The projection 29 may be elongate. The protrusions 30 may result in a certain area of the rotating member having an enlarged cross-section. The protrusion 29 advantageously extends from the side of the piston rod 6 facing the proximal end 3 away from the proximal end along the axis a.

From the situation shown in fig. 6A, the piston rod 6 is rotated and translated distally away from the proximal end 3, establishing a mechanical interconnection between the protrusions 30 and 29, e.g. by mechanical contact of the protrusions 29 and 30 (see fig. 6). A splined connection between the piston rod 6 and the rotational member is thereby established and the indicator turns. The indicator rotation follows the rotation of the piston rod. In particular, the piston rod and the indicator are rotated by the same angle. Thus, a rotational movement of the piston rod 6 relative to the housing 2 is converted into a rotational movement of the indicator 5 relative to the housing 2. From the situation shown in fig. 6A, the indicator is rotated when a further dose is dispensed from the medication delivery device.

Such a drive assembly may for example be used for counting down the last number of doses of the available drug in the drug delivery device. In this way, the number of different indexing elements that have to be provided can be reduced. It is therefore advantageous to provide only one indicating surface.

Fig. 7 shows a diagonal cross-sectional view of a seventh embodiment of the drive assembly 1. This embodiment substantially corresponds to the embodiment described with reference to fig. 5. In contrast thereto, the indicator 5 is movable along the axis a relative to the housing and/or relative to the piston rod 6. In particular, the indicator 5 may be movable away from the distal end 4 and/or away from the proximal end 3.

In contrast to the embodiment described with reference to fig. 5, in this embodiment the drive member 31 of the drive assembly is explicitly shown. A drive member 31, such as a drive sleeve, is movable along the axis. The drive member 31 is preferably fixed against rotation relative to the housing 2. The drive member is arranged on one side of the proximal end 3.

The indicator 5 is coupled to the drive member 31 such that it follows the movement of the drive member along the axis a. The indicator 5 according to this embodiment may thus be moved along said axis relative to the piston rod 6 and/or the housing 2.

Unintentional rotational movement of the indicator 5, for example due to vibrations, can be prevented. To this end, a brake spring (not explicitly shown) may be provided to prevent rotational movement of the indicator 5 relative to the housing and/or the drive member, which rotational movement of the indicator is not caused by translational movement of the indicator and the piston rod relative to each other and/or translational movement of the piston rod relative to the housing.

The indicator part 12 is held in the drive member. The indicator 5 is fixed against movement along said axis relative to the drive member 31. Alternatively, the indicator 5 may be fixed against axial movement relative to the housing 2 (not explicitly shown). In this case, the indicator 5 will be decoupled from the movement of the drive member 31.

The indicator 5 may be coupled to the drive member 31 with a mechanical stop 32, for example a notch, in which the indicator 5, in particular the indicating part 12, may be arranged. The indicating surface 13 is preferably visible from the outside through the drive member 31. For this purpose, a window 33 may be provided on the drive member 31.

For setting a dose, the drive member 31 and the indicator 5 may be moved proximally with respect to the piston rod 6, in particular with respect to the housing 2. The piston rod preferably does not move during dose setting. For delivering a medicament (dose dispensing), the drive member 31 and the indicator may be moved distally relative to the piston rod 6, in particular distally relative to the housing 2. This movement of the drive member 31 may transfer a force to the piston rod 6, causing the piston rod 6 to translate in the distal direction and thus causing the indicator 5 to rotate. The indicator 5 follows the rotational movement of the piston rod 6. Thus, a rotational movement of the piston rod 6 relative to the housing 2 is converted into a rotational movement of the indicator 5. The rotary member 7 is preferably coupled to the piston rod 6 via a splined connection.

Fig. 8 shows a diagonal cross-sectional view of an eighth embodiment of the drive assembly 1. This embodiment substantially corresponds to the embodiment described with reference to fig. 6 and 6A. In contrast thereto, the indicator 5 is movable along the axis a relative to the housing and relative to the piston rod 6. The drive member 31 is provided as described with reference to fig. 7. The indicator 5 may follow the movement of the drive member 31 along the axis a away from the distal end 4 and towards the distal end 4. The coupling between the rotary member 7 and the piston rod 6 may operate as described with reference to fig. 6 and 6A.

To set a dose, the drive member 31 and the indicator 5 are moved proximally in the axial direction. The piston rod 6 is preferably not moved. The indicator preferably does not rotate relative to the housing and/or the drive member. For delivering a dose (dose dispensing), the drive member may be moved in a distal direction, e.g. towards the housing 2. The movement of the drive member transmits a force to the piston rod 6, which force causes the piston rod to move in the distal direction. Distal movement of the piston rod 6 coupled to the indicator 5 causes the indicator 5 to (only) rotate if the protrusions 30 and 29 interact mechanically, e.g. by mechanical contact.

Fig. 9 shows a diagonal cross-sectional view of a ninth embodiment of the drive assembly 1. This embodiment essentially corresponds to the embodiment described with reference to fig. 5. In contrast thereto, the piston rod 6 and the rotation member 7 are coupled to each other to allow a relative rotational movement of the piston rod 6 and the rotation member 7.

The rotation member 7 is threadedly engaged with the piston rod 6, preferably by means of a female thread engaging a male thread. Each thread is preferably a helical thread. The piston rod 6 may comprise a (male) thread 35 arranged on an inner wall 34 of the piston rod 6, for example in the area of the opening 16 through which the rotation member 7 extends. The outer surface of the rotation member 7 may comprise (female) threads. The thread 36 may be provided, for example, with a recess 17. The piston rod 6 is threadedly coupled to the housing 2 via a (female) thread 27. The piston rod 6 is preferably threadedly engaged to the housing 2.

The pitch of the thread 36 for providing a threaded coupling between the piston rod 6 and the rotational member 7 may be different from the pitch of the thread 27 for providing a threaded coupling between the piston rod 6 and the housing 2.

The pitch of threads 36 may be wider or narrower than the pitch of threads 27. The rotation angle of the piston rod 6 and the indicator 5 may thus be different. By suitably designing these pitches with respect to each other, the amount of rotation of the indicator 5 can be adjusted separately from the amount of rotation of the piston rod 6. The pitches may have the same handedness or opposite handedness. The pitches may have different angles with respect to the axis a.

According to fig. 9, for example, the pitch of the thread 36 is wider than the pitch of the thread 27. The angle of thread 36 to axis a, when viewed projected onto a plane containing axis a, is less than the angle of thread 27 to axis a when viewed projected onto said plane.

The threaded coupling of the piston rod 6 and the rotational member 7 has a lead which is larger than the threaded coupling of the piston rod and the housing 2. The threads 27, 36 may have the same handedness, e.g. both clockwise. The rotational angle of the indicator 5 relative to the housing 2 is smaller than the rotational angle of the piston rod 6 relative to the housing.

For setting a dose, the drive member may be moved in a proximal direction along the axis, e.g. away from the housing 2. The piston rod 6 does not move during setting. The indicator 5 does not move during the setting process. For delivering a dose (dose dispensing), the drive member may be moved in a distal direction, e.g. towards the housing 2. The movement of the drive member transmits a force to the piston rod 6 which causes the piston rod to move in the distal direction and to rotate about the axis a. Distal movement and rotational movement of the piston rod 6 coupled to the indicator 5 causes the indicator 5 to turn. The rotation angle of the indicator 5 and the piston rod 6 relative to the housing 2 may be different. The piston rod 6 may drive a piston of a medicament cartridge (not explicitly shown) in a distal direction resulting in a dose of medicament being dispensed from the cartridge.

If dispensing of one of a plurality of doses from a medication delivery device comprising a respective drive assembly 1 requires that the piston rod is rotated a given angle, e.g. 1/3 fig. (120 deg.), and translated a corresponding distance, the indicator 5 may be rotated a smaller angle. The number of index elements 14 that can be placed in an index position on an index surface can be increased in this manner. The indicator 5 may be rotated relative to the piston rod, for example during dispensing of a dose from the medication delivery device.

Fig. 10 schematically shows the relative movement of the piston rod and the indicator with respect to each other when the indicator and the piston rod are threadedly coupled and the piston rod and the housing are threadedly coupled, similar to the discussion with reference to fig. 9.

As shown in fig. 10, when the piston rod is rotated and translated through the housing, a representative point Q of the piston rod on axis a, e.g. a point on the outer surface of the piston rod, moves (maps) along line PH to point Q'. The line PH may represent the angle of the thread for coupling between the housing and the piston rod with respect to the axis a, e.g. the angle of the thread 27 of fig. 9. The threads have a pitch P1. The piston rod moves along the axis a relative to the housing and displaces about an axial displacement AD. The piston rod rotates the RPH relative to the housing. The pitch of the threaded coupling for threadedly coupling the rotary member to the piston rod, e.g. the pitch of the thread 36 is P2. The line IH may represent the angle of the thread providing the coupling between the rotational member and the piston rod with respect to the axis a. Lines IH and IH' may run in parallel. The indicator may rotate the RIH while the piston rod rotates the RPH. P2 is greater than P1. RIH is less than RPH.

In general, RIH and RPH are related by the following formula:

RIH＝RPH*(P2-P1)/P2

accordingly, the indicator and the piston rod may be rotated by different amounts, e.g. different angles.

If P2 > P1, RIH is less than RPH, if P2 and P1 are in the same direction, i.e. the indicator rotates less than the piston rod; or RIH is greater than RPH if P2 is rotated in the opposite direction relative to P1 (the opposite direction can be taken into account by inserting-P2 in the above equation), i.e. the indicator is rotated more than the piston rod.

If P2 < P1, the indicator is rotated in the direction opposite to the direction of rotation of the piston rod. In fig. 10, the opposite rotation of the indicator with respect to the piston rod will be directed to the right of axis a.

Fig. 11 shows a cross-sectional view of a tenth embodiment of the drive assembly in a first, starting position. Fig. 11A shows a cross-sectional view of the tenth embodiment in a second position, i.e. a dose setting position. Fig. 11B shows a cross-sectional view of the tenth embodiment in a third, partly dose dispensing position. Fig. 11C shows a cross-sectional view of the tenth embodiment in a third position, e.g. after rotation of the indicator.

This embodiment corresponds substantially to the embodiment described with reference to fig. 7 and 8. In particular, the indicator 5 is movable along the axis a with respect to the piston rod 6 and with respect to the housing 2.

The indicator 5 is coupled to the drive member 31. The indicator 5 is fixed against movement along the axis a relative to the drive member 31. This relative movement may be prevented by a mechanical stop 32 of the drive member 31, for example a notch, in which the indicator 5 may be arranged. The indicator 5 follows the movement of the drive member 31 along the axis a. The piston rod 6 is moved distally along the axis a and rotated about the axis a.

A partial region of the rotation member 7 is arranged within the piston rod 6, for example within a cavity of the piston rod 6. The rotation member 7 has a projection 30, preferably a plurality of projections 30. Each projection 30 may be formed integrally with the rotary member or as a separate element connected to the rotary member. The two projections 30 may be oppositely disposed with respect to each other. The two projections 30 may be aligned along a line running obliquely or perpendicularly with respect to the axis a. Each projection 30 may project radially from the rotary member 7, i.e. perpendicularly to the axis a. Each projection 30 may be arranged in or at the distal end region of the rotation member 7. Each projection 30 may be, for example, a peg, knob, lug, or pin. Alternatively, each projection 30 may be partially or fully threaded (not expressly shown).

One or more protrusions 29 are provided in the piston rod 6. The protrusions may protrude from the inner wall 34 of the piston rod 6. Each protrusion 29 may be formed integrally with the piston rod or as a separate element connected to the piston rod 6. The individual protrusions 29 shown in the figures may be part of a single (male) thread 35. The thread 35 may be a helical thread.

The rotary member 7 is freely movable along the axis a in the area between two adjacent protrusions 29, i.e. it is not rotated by interaction with the piston rod 6. The distance along the axis a that the rotation member 7 is freely movable relative to the piston rod 6 may correspond to the distance between adjacent protrusions 29 or be determined by the distance between adjacent protrusions 29, e.g. by the width of the thread 35. The thread 35 may be a loose thread, i.e. a thread where the corresponding thread does not (tightly) engage it, e.g. similar to the rotary member 7. The protrusions 29 may preferably be adapted to limit the distance the rotation member 7 may move relative to the piston rod 6 but not interact with one of the protrusions 29.

The protrusions 29 and 30 may be configured to mechanically contact each other when the rotation member and the piston rod are moved relative to each other along the axis a and/or when the piston rod 6 is moved away from the proximal end 3, e.g. for a medicament dispensing procedure.

Each protrusion 30 of the rotation member 7 may be in mechanical contact with the piston rod 6, in particular with its inner wall 34, or arranged at a distance from said inner wall which is smaller than the height of the protrusion 29 relative to the inner wall 34.

The movement of the indicator 5 relative to the piston rod 6 for the different positions shown in fig. 11, 11A, 11B and 11C is schematically shown in fig. 12 and explained with reference to fig. 12. Fig. 12 shows similar contents to those in fig. 10.

Starting from the position shown in fig. 11, the rotation member is moved away from the distal end 4, in particular away from the proximal end 3 of the housing 2, for example by correspondingly moving the drive member 31 proximally. The mechanical contact of the projections 29 and 30 is advantageously avoided (see fig. 11A). Therefore, the rotary member 7 does not rotate. The axial movement of the rotation member may correspond to setting a dose of medicament, for example by a user of the medicament delivery device. The distance between adjacent protrusions 29 is preferably selected to allow a relative movement of the indicator 5 with respect to the piston rod 6 of a predetermined distance without causing the piston rod 6 and/or the rotation member 7 to rotate due to the interaction of the piston rod 6 and the rotation member 7. The predetermined distance may correspond to the distance the drive member 31 has to be moved to set a dose. In the context of FIG. 12, the projection 30 correspondingly moves along axis A from position S1 to S2.

Thereafter, the rotation member 7 together with the indicator 5 and the drive member 31 is moved axially towards the distal end 4 of the housing 2 (see fig. 11B). The kinetic energy transferred by such a movement may be used to move the piston rod 6 distally away from the proximal end 3, e.g. for dispensing a medicament from a medicament delivery device. During a first part of the distance the rotation member 7 moves towards the distal end 4, the rotation member 7 is decoupled from the piston rod. When the rotary member moves the first part along the axis a towards the distal end 4, i.e. from S2 to S3 in fig. 12, there is no rotational movement of the rotary member relative to the housing.

Thus, the dose to be administered may be partially dispensed before the indicator 5 is rotated, since the piston rod 6 may be translated and freely rotated in order to dispense the dose relative to the rotation member 7 over a certain distance, e.g. less than the width of the thread 35. The width of the thread 35 or the distance between adjacent lobes is indicated by WT in fig. 12.

In the position shown in fig. 11B, the protrusion 30 preferably mechanically contacts the protrusion 29, the protrusion 29 distally constraining the distance the rotational member 7 can freely travel.

Thus, during a second part of the movement of the rotation member 7 towards the distal end 4, the rotation member is rotated, as shown in fig. 11C. The projection 30 is guided along the projection 29 by the mechanical interaction between the projections 29 and 30, which causes the rotation member 7 to rotate about the axis a. In this way the indicator 5 is caused to rotate. Thus, rotational and translational movement of the piston rod 6 relative to the housing is translated into rotational movement of the indicator 5 relative to the housing 2 and/or relative to the piston rod 6. The next index element 14 in the column may be rotated to the index position, for example below the window 33 of the drive member 31. In fig. 12, the rotation of the rotary member 7 caused by the rotation and translation of the piston rod 6 rotates the protrusion 30 to the position S4. With respect to the axial component of this position, position S4 corresponds to position S1.

The remaining undescribed elements in fig. 12 correspond to those in fig. 10. Lines IH, IH 'and IH' run in parallel.

As in fig. 10, RIH ═ RPH (P2-P1)/P2. (1)

The ratio of the distance that the drive member 31 moves distally relative to the total distance that the drive member 31 moves distally, i.e. the ratio of the distance over which the indicator is rotated, is given by:

1/[MechAdv*P1/(P2-P1)+1] (2)

among these, mechdv is a mechanical advantage. Mechdrv may be derived from the distance d1 that the drive member 31 is moved distally (to dispense a single dose) compared to, for example, the distance d2 that the piston rod is moved (during dose dispensing of a single dose). Preferably, d1 > d 2. d2 may be given by the axial displacement AD. MechAdv may be 1 (1: 1) or greater than 1, preferably greater than or equal to 2 (2: 1). Particularly preferably, MechAdv is 3 or more (3: 1). The drive assemblies described above and below may also be configured to provide this mechanical advantage.

It is assumed that the piston rod 6 is rotated by a first amount, e.g. 1/3, i.e. 120, for delivering a single dose. If it is desired to rotate the indicator by a second amount, which is less than the first amount, for example, 1/9, i.e., 40 °, P1 is 2/3 × P2 according to equation (1).

If mechdv is 3, then the ratio of the distance over which the indicator is rotated of the total distance traveled distally by the drive member is 1/(3 × 2+1) ═ 1/7, according to equation (2). Thus, if the drive member has traveled 17.5mm in total, the indicator is rotated during the last 2.5 mm.

Thus, rotation of the indicator does not occur until the end of the dose dispense sequence is approached.

Unlike the embodiment wherein the indicator and the piston rod are rotated simultaneously and the indicator is not decoupled from the rotational movement of the piston rod for a part of the movement of the piston rod along said axis, the present embodiment is advantageous for providing a drug delivery device providing the user with an audible or visual feedback that a dose has been completed, preferably for each dose to be dispensed. Feedback may be given by coupling a feedback member (not explicitly shown) to the indicator, the feedback member being activated by rotation of the indicator. Rotation of the indicator preferably does not occur until near the end of dispensing of a single dose as described above.

A medicament delivery device suitable for incorporating a drive assembly as described above, as well as other features associated with the drive assembly, will be described below with reference to fig. 13 to 14.

Fig. 13 shows a diagonal cross-sectional view of a first embodiment of a medication delivery device. Fig. 13A shows a side view of the first embodiment of the medicament delivery device in a first position, e.g. a cartridge filled position. Fig. 13B shows a cross-sectional view of the first embodiment of the medicament delivery device in a second position, e.g. after a first dose setting. Fig. 13C shows a cross-sectional view of the first embodiment of the medicament delivery device in a third position, e.g. after the first dose has been dispensed. Fig. 13D shows a sectional view of the drug delivery device in a fourth position, e.g. after setting of a final dose. Fig. 13E shows a sectional view of the drug delivery device in a fifth position, e.g. a position after final dose dispensing.

The medicament delivery device 50 comprises a cartridge retaining part 51, and a main (outer) housing part 2. The proximal end 52 of the cartridge retaining member 51 and the distal end 4 of the main housing 2 are secured together using any suitable means known to those skilled in the art. In the illustrated embodiment, the cartridge retaining member 51 is secured within the distal end 4 of the main housing member 2.

A cartridge 53 from which a plurality of doses of a pharmaceutical product may be dispensed is disposed within the cartridge retaining member 51. The pharmaceutical product may for example be one of the above mentioned pharmaceutical products. A piston 54 is retained in the proximal end of the barrel 53.

A removable end cap may be releasably retained on the distal end 55 of the cartridge retaining member 51 (not explicitly shown). The removable end cap may optionally be provided with one or more window apertures through which the position of the piston 54 within the barrel 53 may be viewed.

The distal end 55 of the cartridge retaining part 51 may be provided with a distal threaded region (not explicitly shown). This area may be designed for attachment of a suitable syringe assembly to allow dispensing of medication from barrel 53.

In the illustrated embodiment, the main housing member 2 is provided with an inner housing 56. The inner housing 56 is fixed against rotational and/or axial movement relative to the main housing part 2. The inner housing 56 is provided with a rack 57 extending along the main axis a of the inner housing 56. Alternatively, the inner housing 56 may be integrally formed with the main housing member 2.

Furthermore, the inner shell 56 may be provided with a plurality of guide lugs (not shown) and/or a jaw arrangement (not shown). The jaw means may be an integral part of the inner housing 56 or may be a separate part as shown.

The piston rod 6 extending through the main housing 2 has a first set of recesses (not explicitly shown) extending longitudinally along the outer surface of the piston rod 6. The second set of recesses 58 extend longitudinally along the inner surface of the piston rod 6. A first set of recesses of the piston rod 6 extends through and engages the jaw means of the inner housing 56 to prevent the piston rod 6 from moving in the proximal direction during setting of the device. A bearing surface 59 at the distal end of the piston rod 6 is arranged to mechanically contact, preferably abut against, the proximal end face of the piston 54. In the illustrated embodiment, the longitudinal spacing of the first and second sets of notches 58 is substantially equal.

A gear arrangement 60 comprising a carrier 61 and/or a gear 62 is located in a channel in the piston rod 6, said gear being free to rotate within the carrier 61. The pawl arms on the carrier 61 releasably engage the second set of recesses 58 (not explicitly shown) of the piston rod 6. The pawl arms of the carrier 61 are designed to transmit a force in the distal direction to the piston rod 6 during dispensing and to allow a relative movement in the proximal direction between the gear wheel 60 and the piston rod 6 during setting. The teeth of the gear 62 permanently engage the teeth of the rack 57 of the inner housing 56.

The drive member 31 extends around the piston rod 6. The drive member 31 comprises a rack means 63 and an activation means 64. The rack member 63 and the activation member 64 are fixed to each other to prevent rotational and/or axial movement therebetween.

Alternatively, the drive member 31 may be a single component consisting of the integrated rack component 63 and the activation component 64.

The rack member 63 is provided with a rack 65 extending along the main axis of the rack member 63. The teeth of the rack 65 of the rack member 63 permanently engage the teeth of the pinion 62.

The drive member 31 has a plurality of guide slots (not shown) in which guide lugs (not shown) of the inner housing 56 are located. The guide slots define the allowable axial range of movement of the drive member 31 relative to the housing part 2. In the illustrated embodiment, the guide slots also prevent rotational movement of the drive member 31 relative to the main housing part 2.

The activation part 64 of the drive member 31 has a plurality of gripping surfaces 66 and a dispensing face 67.

The drug delivery device 50 comprises the indicator 5 and the rotation member 7 as described further above with reference to the previous embodiments relating to drive assemblies. The indicator 5 is rotatable about the axis a relative to the piston rod 6 and the main housing part 2. The piston rod 6 is movable in the distal direction along the axis a. The indicator 5 is coupled to the piston rod 6. The indicator 5 may rotate as the piston rod is moved in the distal direction. The rotation member 7 may be threadedly engaged with the piston rod 6, e.g. with a threaded engagement in the region of an opening 16 on the piston rod 6 through which the rotation member 7 extends. A thread, e.g. a full thread or a partial thread, may be used for the opening 16 to threadedly engage the rotation member 7 and the piston rod 6. The rotating member 7 may be a threaded shaft screwed in the opening 16. The opening 16 is arranged on the side of the piston rod 6 facing the proximal end 4. The rotary member 7 may be threaded all the way through (e.g., threads 36 in fig. 13A-13E). The threads of the opening or of the rotary member, respectively, are preferably helical threads (full or partial threads, male or female threads, respectively). The indicator 5 is fixed against relative movement along the axis a with respect to the housing part 2.

The rotary member 7 may be supported by the mechanical support 68 so as not to be displaceable in a radial direction with respect to the axis a. The mechanical support 68 may be disposed on or integral with the inner housing 56. The mechanical support 68 may correspond to the mechanical support otherwise described above.

The operation of the medication delivery device will now be described.

In the starting position, an indexing element, such as the letter P, which does not dispense a dose, for example, indicating that the initial dose is still available, can be seen from the outside through the window 15 in the housing part 2 in the indicating position, as shown in fig. 13A.

To set a dose, the user grips the gripping surface 66 of the drive member 31. The user then pulls the drive member 31 in a proximal direction away from the housing component 2, thereby moving the rack component 63 in a proximal direction.

Proximal movement of the rack member 63 causes the gear 62 to rotate and move proximally due to the engagement of the teeth of the gear 62 of the gear 60 with the teeth of the rack 65 of the rack member 63 and the teeth of the rack 57 of the inner housing 56, thereby moving the gear 60 in a proximal direction, as shown in fig. 13B. The indicator 5 does not rotate during this movement.

The piston rod 6 is prevented from moving proximally by the interaction of the catch means of the inner housing 56 with the first set of recesses on the piston rod 6. As the drive member 31 travels in the proximal direction relative to the piston rod 6, the catch arms of the carrier 61 are displaced inwardly by interaction with the second set of recesses 58 of the piston rod 6.

The proximal travel of the drive member 31 is limited by the guide slot of the rack member 63. At the end of the stroke of the drive member 31, the pawl arm of the carrier 61 engages the next sequential recess of the second set of recesses 58 of the piston rod 6, as shown in fig. 13B. The action of the pawl arms of the carrier 61 positively engaging the second set of recesses 58 of the piston rod 6 creates an audible and visual feedback to the user to indicate that a dose has been set. The indicator does not rotate during dose setting.

After setting of a dose, the user then dispenses the dose by pressing the dispensing face 67 of the activation part 64 of the drive member 31. With this action, the drive member 31 and the rack member 63 are axially moved in the distal direction relative to the main housing part 2, as shown in fig. 13C. When the teeth of the gear 62 of the gear arrangement 60 engage the teeth of the rack 65 of the rack member 63 and the teeth of the rack 57 of the inner housing 56, the gear 62 of the gear arrangement 60 is caused to rotate and move in the distal direction, thereby moving the gear arrangement 60 longitudinally in the distal direction. When the pawl arms of the carrier 61 of the gear arrangement 60 engage the second set of recesses 58 of the piston rod 6, the piston rod 6 is caused to move longitudinally in a distal direction relative to the main housing part 2, in particular relative to the inner housing 56.

Axial movement of the piston rod 6 distally causes the bearing surface 59 of the piston rod 6 to abut the piston 54 of the barrel 53. This results in a dose of medicament being dispensed from the barrel, for example through a syringe (not shown) which may be connected distally to the medicament delivery device.

The distal travel of the drive member 31 is limited by a guide slot (not shown) of the rack member 63. Visual and tactile feedback indicating that a dose has been dispensed is provided by the interaction of the catch means (not shown) of the inner housing 56 with the first set of recesses (not shown) of the piston rod 6.

The coupling between the piston rod 6 and the rotary member 7 causes the indicator 5 to turn the next indexing element 14 in the column, e.g. the single digit "7" in fig. 13C, into the indicating position during the distal axial movement of the piston rod 6. The indicator 5 is adapted to count down the number of doses remaining for dispensing.

Additional doses up to the predetermined maximum number of doses may be delivered as desired. Fig. 13D and 13E illustrate setting and dispensing a final dose from the drug delivery device 50. The mechanism corresponds to the mechanism described with reference to fig. 13A to 13C. The index elements 14 on the indicating surface 13 are in turn rotated to the indicating position and preferably counted down, e.g. to "0", as the dispensing process continues.

Figure 13E shows the drug delivery device after the maximum number of doses has been delivered. In this case, the proximal end face 68 of the carrier 61 may abut against the inner distal end face 69 of the piston rod 6 to prevent further axial movement of the gear means 60 and thus the drive member 31 in the proximal direction. Of course, other embodiments of the drive assembly as described above may be implemented in the medication delivery device according to this embodiment. Due to the pure translational movement of the piston rod 6, the drive assembly as described above with reference to fig. 1 to 4 is particularly suitable for implementation in a medicament delivery device according to the present embodiment.

Fig. 14 shows a diagonal cross-sectional view of a second embodiment of a medication delivery device. Fig. 14A shows a side view of the second embodiment of the medicament delivery device in a first position, e.g. a cartridge filled position. Fig. 14B shows a cross-sectional view of the second embodiment of the medicament delivery device in a second position, e.g. a position after the first dose has been set. Fig. 14C shows a cross-sectional view of the second embodiment of the medicament delivery device in a third position, e.g. after the first dose has been dispensed. Fig. 14D shows a cross-sectional view of the second embodiment of the medicament delivery device in a fourth position, e.g. after setting of a final dose. Fig. 14E shows a cross-sectional view of the second embodiment of the medicament delivery device in a fifth position, e.g. after final dose dispensing.

The medicament delivery device 50 comprises a cartridge retaining part 51, and a main (outer) housing part 2. The proximal end 52 of the cartridge retaining member 51 and the distal end 4 of the main housing 2 are secured together using any suitable means known to those skilled in the art. In the illustrated embodiment, the cartridge retaining member 51 is secured within the distal end 4 of the main housing member 2.

A cartridge 53 from which a number of doses of a pharmaceutical product can be dispensed is provided within the cartridge retaining member 51. A piston 54 is retained within the proximal end of barrel 53.

A removable end cap may be releasably retained on the distal end 55 of the cartridge retaining member 51 (not explicitly shown). The removable end cap may optionally be provided with one or more window apertures through which the position of the piston 54 within the barrel 53 may be viewed.

The distal end 55 of the cartridge retaining part 51 may be provided with a distal threaded region 70. Threaded region 70 may be designed for attachment of a suitable syringe assembly (not shown). A pharmaceutical product, such as that otherwise described above, may be dispensed distally from the barrel 53, such as through a needle cannula.

In the illustrated embodiment, the main housing member 2 is provided with an inner housing 56. The inner housing 56 is fixed against rotational and/or axial movement relative to the main housing part 2. The inner housing 56 is provided with a threaded annular opening 71 extending through the distal end of the inner housing 56. The threaded annular opening 71 may include a series of partial threads (as shown) or full threads. Alternatively, the inner housing 56 may be integrally formed with the main housing member 2. In addition, the inner housing 56 may be provided with a plurality of guide slots and jaw arrangements. The inner housing 56 may be formed from the mechanical supports described for the previous embodiments. The opening 71 may correspond to the previously described openings (e.g., the support 8 and the opening 9 in fig. 1-12).

A first thread 72 is formed at the distal end of the piston rod 6. The piston rod 6 is substantially circular in cross-section. The first thread 72 of the piston rod 6 extends through and is in threaded engagement with the threaded annular opening 71 of the inner housing 56. The pressure foot 73 is located at the distal end of the piston rod 6. A pressure foot 73 is provided against the proximal face of the piston 54. A second thread 74 is formed at the proximal end of the piston rod 6 (see fig. 14B to 14D). The second threads 74 may include a series of partial threads (as shown) or full threads. The second thread may be formed on one or more flexible arms 75 of the piston rod 6.

The first and second threads 72, 74 are oppositely disposed.

In the illustrated embodiment, the first thread 72 may be provided with a plurality of features (not shown) which cooperate with a part of the thread of the threaded annular opening 71 preventing the piston rod 6 from moving in the proximal direction during setting of the device.

The drive member 31 extends around the piston rod 6. The drive member 31 includes, for example, a threaded member 76 having a substantially cylindrical cross section, and an activation member 64. The threaded member 76 and the activation member 64 are fixed to one another to prevent rotational and/or axial movement thereof. Alternatively, the drive member 31 may be a unitary component comprising or consisting of the integrated threaded component 76 and the activation component 64.

In the illustrated embodiment, the threaded member 76 is provided with a longitudinally extending helical thread 77 formed on the inner cylindrical surface, i.e. a thread extending along the axis a. The proximal side of the helical thread 77 is flanked by flanks designed to remain in contact with the second thread 74 of the piston rod 6 when dispensing a dose, whereas the distal side of the helical thread 77 is flanked by flanks designed to allow disengagement of the second thread 74 of the piston rod 6 when setting a dose. In this way, the helical thread 77 of the threaded member 76 releasably engages the second thread 74 of the piston rod 6.

The drive member 31 has a plurality of features formed on an outer surface that are designed to move axially in guide slots of the inner housing 56. The guide slots define the allowable axial range of movement of the drive member 31 relative to the housing part 2. In the illustrated embodiment, the guide slots also prevent rotational movement of the drive member 31 relative to the main housing part 2.

The activation part 64 of the drive member 31 has a plurality of gripping surfaces 66 and a dispensing face 67.

The drive member 31 is provided with a detent designed to interact with a catch means of the inner housing 56.

The drug delivery device 50 comprises the indicator 5 and the rotation member 7 as described above for the previous embodiments involving the drive assembly. The indicator 5 is rotatable about the axis a relative to the piston rod 6 and the main housing part 2. The piston rod 6 is movable in a distal direction along the axis a and rotatable about the axis a. The indicator 5 may be coupled to a piston rod 6. The indicator 5 is coupled to the drive member 31. Preferably, the indicator is fixed against relative movement along axis a with respect to the drive member 31. The drive member 31 may extend around the indicating surface 13.

The thread 36, which may be formed by a partial thread or a full thread, is formed on the rotary member 7, preferably integrally with the rotary member 7. The threads 36 may be male or female threads. The thread 36 is preferably formed in the distal end region of the rotation member 7. The thread 36 is preferably a helical thread.

On the inner wall 34 of the piston rod 6, a thread 35 is formed, preferably integrally with the piston rod 6. The threads 35 may be male or female threads. The thread 35 is preferably a helical thread. Preferably, the thread 35 is of a thread type, for example female, and the thread 36 is of a thread type different from the thread 36, for example male.

The indicator 5 may be coupled to the piston rod 6 via threads 35 (see fig. 14B to 14D) and 36 for rotating the indicator.

The rotation member 7 may be freely movable along the axis a in a certain area relative to the piston rod 6, i.e. without causing mechanical contact and/or rotation of the piston rod. The threads 35 and 36 may be configured to leave sufficient slack between them to allow such movement of the rotary member 7 relative to the piston rod 6. Thereby facilitating setting of a dose by moving the drive member 31 and the indicator 5 away from the proximal end 3. For this purpose, the thread 35 is preferably wider than the thread 36.

The operation of the medicament delivery device 50 will now be described.

In the starting position, an indexing element, such as the letter P, which does not dispense a dose, for example, indicating that the initial dose is still available, can be seen from the outside through the window 15 in the housing part 2 in the indicating position, fig. 14A.

The window 33 may be provided on the activation member 64. The provision of the window 33 on the drive member 31 is advantageous in that the indexing element is easily identifiable even during dose setting.

To set a dose, the user grips the gripping surface 66 of the drive member 31. The user then pulls the drive member 31 in a proximal direction away from the main housing part 2, fig. 14B. The indicator 5 follows the movement of the drive member. During this movement, the indicator 5 is prevented from rotating relative to the drive member 31 by a braking element 78, for example a braking spring (see fig. 14). The indicating surface 13 may extend along the outside of the braking element 78. The indicator 5 may be held within the activation part 64 of the drive member.

Alternatively, the indicator may be rotated during movement of the indicator away from the proximal end, i.e. during setting, but prevented from rotating during movement towards the proximal end 3, i.e. during dispensing (not explicitly shown). However, the rotation of the indicator during dose dispensing preferably overrides the rotation of the indicator during dose setting, since the user can see the correct indexing element even when the next dose has been set but not yet dispensed.

The braking element 78 may also prevent the indicator 5 from rotating under the influence of vibration or shock loads. The braking element 78 is advantageously configured to allow the indicator to rotate (only) if said rotation is caused by a relative movement of the piston rod and the indicator with respect to each other.

In view of the relief between the threads 35 and 36, the piston rod does not move during setting, i.e. the threads 35 and 36 do not interact during setting.

The piston rod 6 is prevented from proximal movement by the partial threads of the threaded annular opening 71 of the inner housing 56 interacting with the thread feature on the first thread 72 of the piston rod 6. When the drive member 31 is advanced in the proximal direction relative to the piston rod 6, the second thread 74 of the piston rod 6 is displaced radially inwards by the flanks of the distal side of the helical thread 77 of the drive member 31.

Proximal travel of drive member 31 is limited by guide slots (not shown) of inner housing 56 to a distance corresponding to substantially one thread pitch of helical thread 77 of drive member 31. At the end of the stroke of the drive member 31 the second thread 74 of the piston rod 6 engages the helical thread 77 under the action of the flexible arm 75 of the piston rod 6.

By this action, the drive member 31 is displaced in the proximal direction with respect to the piston rod 6 by a distance substantially equal to one pitch of the helical thread 77 of the drive member 31, as shown in fig. 14B. The second thread 74 engages the action of the helical thread 77 of the drive member 31 under the influence of the force provided by the flexible arm 75, providing an audible and tactile feedback to the user to indicate that a dose has been set.

After setting of a dose, the user then dispenses the dose by pressing the dispensing face 67 of the activation part 64 of the drive member 31, i.e. by moving the drive member towards the proximal end 3, as shown in fig. 14C. With this action, the drive member 31 is axially moved in the distal direction relative to the main housing part 2. When the second thread 74 of the piston rod 6 positively engages the helical thread 77 of the drive member 31, the piston rod 6 is caused to rotate relative to the inner housing 56 by an axial movement of the drive member 31 in the distal direction. When the piston rod 6 is rotated, the first thread 72 of the piston rod 6 is rotated in the threaded annular opening 71 of the inner housing 56, causing the piston rod 6 to move axially in the distal direction relative to the inner housing 56.

Distal axial movement of plunger rod 6 causes compression foot 73 to abut piston 54 of barrel 53, causing a dose of medication to be dispensed through the connected needle cannula.

Moreover, the threads 35 and 36 interact with each other, thereby causing the indicator 5 to rotate. Threads 36 may engage threads 35. The coupling between the piston rod 6 and the rotary member 7 causes the indicator to turn the next indexing element 14 in the column, for example the single digit "7" in fig. 14C, to the indicating position. The indicator 5 is adapted to count down the number of remaining doses for dispensing. The indicator 5 rotates less than the piston rod 6.

If the number of doses to be dispensed requires 120 of indicator rotation, the indicating surface may be rotated 30 for each delivered dose.

Distal travel of drive member 31 is limited by guide slots (not shown) of inner housing 56. Audible and tactile feedback indicating that a dose has been dispensed is provided by the interaction of the (further) detent (not shown) of the drive member 31 and the click-on means (not shown) of the inner housing 56.

Other doses up to a predetermined maximum number of doses may be delivered as required. Fig. 14D and 14E illustrate setting and dispensing of a final dose from the drug delivery device 50. The mechanism corresponds to the mechanism described above with reference to fig. 14A to 14C. The indexing elements 14 on the indexing surface 13 are in turn rotated to the indexing position and preferably count down, e.g. to "0", as the dose dispensing progresses. The piston rod 6 travels forward with further dose dispensing.

Figure 14E shows the drug delivery device in a situation where the maximum number of doses has been delivered. In this state, a lug feature (not explicitly shown) on the piston rod 6 may interlock with a lug feature (not explicitly shown) on the drive member 31 to prevent further axial movement of the drive member 31 in the proximal direction.

Of course, other embodiments of the drive assembly as described above may be implemented in a drug delivery device according to such an embodiment.

The drive assembly as described above with reference to fig. 5 to 12 is particularly suitable for implementation in a medicament delivery device according to such an embodiment when the piston rod 6 is translated and rotated.

Claims (19)

1. A drive assembly for a drug delivery device, the drive assembly comprising:

a housing having a proximal end and a distal end;

an axis extending between the proximal end and the distal end;

at least one drive member;

a piston rod adapted to be driven by the drive member along the axis;

an indicator adapted to provide information about the position of the piston rod relative to the proximal end,

wherein the indicator and the piston rod are configured to translate movement of the piston rod relative to the housing into rotational movement of the indicator relative to the housing, and the indicator comprises a rotational member configured to translate movement of the piston rod into rotational movement of the indicator, the indicator being coupleable to the piston rod via the rotational member, and wherein the rotational member is at least partially disposed within the piston rod.

2. The drive assembly according to claim 1, wherein the drive assembly is configured to move the piston rod unidirectionally along the axis.

3. The drive assembly according to claim 1 or 2, wherein the indicator has an indicating surface provided with a plurality of indexing elements, the drive assembly being configured such that at least one indexing element is visible from outside the drive assembly.

4. The drive assembly according to claim 1 or 2, wherein the drive member is movable along the axis relative to the housing, and the indicator is coupled to the drive member such that the indicator follows axial movement of the drive member.

5. The drive assembly according to claim 1 or 2, wherein the drive assembly is configured to constrain or prevent distal movement of the indicator along the axis relative to the housing or relative to the drive member.

6. The drive assembly according to claim 1, wherein one of the rotary member and the piston rod has a protrusion configured to mechanically interact with the other of the rotary member and the piston rod for converting the movement of the piston rod into a rotational movement of the rotary member.

7. The drive assembly as set forth in claim 6 wherein each of said projections comprises one of a male thread, a knob, a rib, a lug, or a pin.

8. The drive assembly according to claim 6, wherein both the rotary member and the piston rod have protrusions configured to mechanically interact.

9. The drive assembly according to claim 6, wherein at least one of the rotary member and the piston rod has a recess configured to mechanically interact with the other of the rotary member and the piston rod for converting the movement of the piston rod into a rotational movement of the rotary member.

10. The drive assembly as set forth in claim 9, wherein said recess includes one of a slot and a female thread.

11. The drive assembly as set forth in claim 9 wherein said projection engages said recess.

12. The drive assembly according to claim 1 or 2, wherein the rotary member has a section configured to threadedly engage the piston rod.

13. The drive assembly according to claim 1 or 2, wherein the drive assembly is configured to move the piston rod distally along the axis and to rotate the piston rod.

14. The drive assembly according to claim 1 or 2, wherein the indicator is coupleable to the piston rod such that the coupling is configured to convert a rotational movement of the piston rod into a rotational movement of equal rotational angles of the indicator.

15. The drive assembly according to claim 1 or 2, wherein the indicator is coupleable to the piston rod such that the coupling is configured to translate rotational movement of the piston rod into rotational movement of different rotational angles of the indicator.

16. The drive assembly according to claim 1 or 2, wherein the drive assembly is configured to restrict or prevent rotational movement of the piston rod.

17. The drive assembly according to claim 1 or 2, wherein the drive assembly is configured to translate distal movement of the piston rod along the axis into rotational movement of the indicator.

18. A drug delivery device comprising:

the drive assembly of claim 1 or 2; and

multiple doses of the drug.

19. The drug delivery apparatus of claim 18, wherein the drive assembly is configured such that the indicator rotates when a dose is dispensed from the drug delivery apparatus.