WO2025094043A1

WO2025094043A1 - End-of-life lockout mechanisms for inhalers

Info

Publication number: WO2025094043A1
Application number: PCT/IB2024/060642
Authority: WO
Inventors: Adam STUART; Stephen HOWGILL
Original assignee: Merxin Ltd
Current assignee: Merxin Ltd
Priority date: 2023-10-30
Filing date: 2024-10-29
Publication date: 2025-05-08
Anticipated expiration: 2026-04-30
Also published as: GB2637900A; GB202316585D0

Abstract

An end-of-life lockout mechanism for an inhaler An end-of-life lockout mechanism for an inhaler of the type that comprises a mechanical button (107) operable by a user to dispense a dose from the inhaler, comprising a lockout activation element (106, 109) configured to locate within the external housing (101a, 101b) of the inhaler, the lockout activation element (106, 109) configured so that operation of the inhaler causes the lockout activation element (106, 109) to move within the housing (101a, 101b), a blocking element (110) configured to locate within the housing (101a, 101b) of the inhaler, the blocking element (110) configured so that the blocking element (110) can move from a first position or first set of positions where operation of the inhaler takes place normally, and a second position blocking operation of the button (107) by a user, wherein operation of the inhaler causes the lockout activation element (106, 109) to move incrementally within the housing (101a, 101b) with each use of the inhaler, until the lockout activation element (106, 109) reaches a pre-set point and causes the blocking element (110) to move to the second position.

Description

END-OF-LIFE LOCKOUT MECHANISMS FOR INHALERS

TECHNICAL FIELD

This invention relates to end-of-life lockout mechanisms for inhalers. In particular, though not exclusively, this invention relates to end-of-life lockout mechanisms for soft mist inhalers. This invention also relates to inhalers having an end-of-life lockout mechanism.

BACKGROUND

Inhalers such as soft mist inhalers (SMIs) use a cartridge or container as the source of the medicament that they deliver. In this type of inhaler, the cartridge contains a volume of medicament for delivery to a user via discrete doses that comprise a portion of the total volume within the cartridge. In use, the cartridge is located within an inhaler assembly that includes a micropump. Delivery of the medicament from the cartridge is achieved by using the micropump, which is normally manually operated/activated by the user. Although reusable inhaler assemblies are known where the cartridge can be removed and replaced once expired, it is more normal for both the inhaler and the cartridge to be disposed of after use, at end-of-life. In use, the inhaler is operated to release a discrete dose of medicament from the cartridge, with the micropump within the inhaler used to deliver the medicament dose from the cartridge.

It is important that a precise and known dose of medicament is delivered each time the inhaler is operated. However, the amount of medicament within the cartridge decreases with each delivered dose. This can lead to a situation where the amount of medicament remaining in the cartridge has dropped below the level necessary to deliver a full dose for any single operation of the inhaler, but is still sufficient to allow the appearance (but not actuality) of successful operation of the inhaler and successful delivery of a full dose. Alternatively or as well as this, operation of the micropump with a cartridge at or towards the end of life can lead to the appearance (but not actuality) of successful delivery of a full dose. Alternatively, it is possible that an over- or under-concentrated dose of medicament could be delivered if use is continued beyond the stated/design limit.

Regulators of medicines can frequently require that some method of dose indication is included in this type of inhaler, and many inhalers contain a mechanism such as a dose counter that provides a precise count of the number of doses remaining, or a dose indicator which provides an indication of the proportion of doses remaining. These counters index or ‘count’ each time the inhaler is used and the intention is that when the remaining dose count reaches zero, a user will know to replace the cartridge with a fresh, fully pressurised cartridge (either by replacing the cartridge, or replacing the entire inhaler). Examples of this type of device are described and shown in US10,929,742, US11 ,544,520, US11 ,369,760, and W02022/002993.

EP2617450 describes and shows an end-of-life mechanism where the button is held inwards at the end- of-life of the inhaler. US9,744,313 describes and shows an inhaler having a mechanism where the drive spring 7 is retained in a compressed state by a button or blocking element 8 until the button is activated. At end-of-life, the upper and lower housing are locked in position relative to one another and are prevented from relative rotation so the inhaler cannot be primed for use. The botton or blocking element

8 cannot be used to release the spring in this locked state. AU2015/202524 describes a similar mechanism.

With many types of end-of-life mechanism or counter, it is often still possible for a user to operate the inhaler even after a zero dose count has been reached. If a user attempts to use the inhaler after a zero dose count has been reached, this can result in issues such as those outlined above.

There therefore remains a need for a mechanism that can help to overcome the aforementioned drawbacks, or which at least provides the public with a useful choice.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an end-of-life lockout mechanism for inhalers which goes some way to overcoming the abovementioned disadvantages or which at least provides the public or industry with a useful choice.

It is a further object of the present invention to provide an inhaler device having an end-of-life lockout mechanism which goes some way to overcoming the abovementioned disadvantages or which at least provides the public or industry with a useful choice.

Accordingly, in a first aspect the present invention may broadly be said to consist in an end-of-life lockout mechanism for an inhaler of the type that comprises a mechanical button operable by a user pressing the button inwards from an outwards position so as to dispense a dose from the inhaler, the end-of-life lockout mechanism comprising: a blocking element configured to locate within the housing of the inhaler, the blocking element and housing further configured so that the blocking element can move from a first position or first set of positions within the housing where operation of the inhaler takes place normally, and a second position; a lockout activation element configured to locate within the external housing of the inhaler, the lockout activation element configured so that each single operation of the inhaler causes the lockout activation element to move incrementally within the housing, until, after a plurality of single operations, the lockout activation element reaches a pre-set point and causes the blocking element to move to the second position; the lockout activation element and blocking element mutually configured to locate within the external housing of the inhaler so that in the second position the button is blocked in the outwards position by the blocking element.

In an embodiment, the lockout activation element activation element comprises a ring.

In an embodiment, the ring comprises gear teeth.

In an embodiment, the ring comprises an extension, extending outwards from the ring.

In an embodiment, the end-of-life lockout mechanism further comprises a cam element configured to interact with the activation element and to connect with the blocking element to cause the blocking element to move to the second position at the pre-set point. In an embodiment, the extension extends outwards from the ring substantially axially.

In an embodiment, the extension extends outwards from the ring substantially circumferentially.

In an embodiment, the blocking element comprises a pin having an elongate main body and a key bit extending from the main body.

In an embodiment, the blocking element comprises a pin having an elongate main body, one end of the main body formed with gear teeth configured to interact with the ring gear teeth in use so as to rotate the main body as the ring rotates, the blocking element further comprising a moving element locating in use onto the main body, the main body and moving element mutually configured so that the moving element will move along the main body as the main body rotates, from the first position or positions to the second position.

In an embodiment, the blocking element comprises a hooked lower end, the housing and hooked lower end configured for mutual engagement in the first position or first set of positions.

In an embodiment, the blocking element further comprises a protrusion extending outwards from the main body substantially towards the upper end of the main body, aligned in substantially the same direction as the hooked lower end.

In an embodiment, the blocking mechanism further comprises a spring configured to operate to cause the blocking mechanism to move to the second position at the pre-set point. in a second aspect the present invention may broadly be said to consist in an end-of-life lockout mechanism for an inhaler of the type that comprises a mechanical button operable by a user pressing the button inwards from an outwards position so as to dispense a dose from the inhaler, the end-of-life lockout mechanism comprising: a blocking element configured to locate within the housing of the inhaler, the blocking element and housing further configured so that the blocking element can move from a first position or first set of positions within the housing where operation of the inhaler takes place normally, and a second position; a lockout activation element configured to locate within the external housing of the inhaler, the lockout activation element configured so that each single operation of the inhaler causes the lockout activation element to move incrementally within the housing, until, after a plurality of single operations, the lockout activation element reaches a pre-set point and causes the blocking element to move to the second position; the lockout activation element and blocking element mutually configured to locate within the external housing of the inhaler so that in the second position the button is blocked in the outwards position by direct contact with the blocking element.

In an embodiment, the ring comprises gear teeth.

In an embodiment, the end-of-life lockout mechanism further comprises a cam element configured to interact with the activation element and to connect with the blocking element to cause the blocking element to move to the second position at the pre-set point.

In an embodiment, the extension extends outwards from the ring substantially axially.

In an embodiment, the blocking mechanism further comprises a spring configured to operate to cause the blocking mechanism to move to the second position at the pre-set point.

With respect to the above description then, it is to be realised that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.

This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS Further aspects of the invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings which show an embodiment of the device by way of example, and in which:

Figure 1 shows a cutaway side view of a known, prior art inhaler from Boehringer-Ingelheim that is typical of a known type of soft mist inhaler, the figure showing internal detail of a housing that encloses a cartridge, the housing having an upper part and a lower or base part, the housing forming a mouthpiece for a user, and a dose-release button located on the housing for triggering the dispensing of a dose of medicament.

Figure 2 shows a side view of another type of known prior art soft mist inhaler from Merxin, the inhaler comprising a housing having a base, the housing and base in use enclosing a cartridge, the upper part of the housing forming a mouthpiece, a dose-release button located on the housing, and a lid hingedly connected to the housing at one side, the lid shown open.

Figure 3 shows a perspective view from above and to one side of a known, prior art inhaler similar to the one shown in figure 2, the lid shown in the open position.

Figure 4 shows a perspective side view of an inhaler according to an embodiment of the present invention, the inhaler similar in structure to those shown in figures 2 and 3, the inhaler having an end-of- life lock-out mechanism located in the housing on the same side as the lid hinge.

Figure 5 shows a perspective side view of the inhaler of figure 4, cut away on the vertical plane to show internal detail of the inhaler and in particular the end-of-life mechanism, the end-of-life mechanism comprising a pin extending along the housing, the pin shown in a normal use position, towards the lower or base end of the inhaler.

Figure 6 shows a perspective view from above and to one side of the inhaler of figure 5.

Figure 7 shows a perspective view from above and to one side of the inhaler of figures 4 to 6 cut away on the horizontal plane just above the lower end of the upper housing part, showing detail of part of the end-of-life mechanism, the mechanism aligned for normal use.

Figure 8 shows a perspective view of the inhaler of figures 4 to 7 from the same angle as figure 7, cut away on the horizontal plane just below the upper end of the upper housing part, showing detail of the upper part of the end-of-life mechanism and the button, the mechanism aligned for normal use.

Figure 9 shows a perspective view of the inhaler of figures 4 to 8 from a similar angle as figure 8, cut away on a horizontal plane slightly above that of figure 8.

Figure 10 shows a perspective top-down view from above and to one side of the inhaler of figures 4 to 9, cut away on a plane slightly above the cutaway plane of figure 9, with a key bit on the pin of the lockout mechanism aligned with a slot in the housing, the pin moving upwards when the key bit is aligned with the slot so as to lock the mechanism. Figure 11 shows a close-up of the end-of-life mechanism and the button on the same cutaway plane and from the same angle as figure 10, the pin in the same alignment as figure 10.

Figure 12 shows a perspective view from above and to one side of the inhaler of figures 4 to 11 cutaway on a horizontal plane slightly above the plane of figure 9 and below that of figures 9 and 10, the pin in the same alignment as figures 10 and 11 .

Figures 13a - 13d show perspective views of an embodiment of the pin of the end-of-life mechanism.

Figure 14 shows a cutaway side perspective view of an inhaler having an end-of-life lockout mechanism according to a second embodiment of the invention, the inhaler similar in configuration and layout to the inhaler of the first embodiment, the end-of-life lockout mechanism in this embodiment comprising a pin and a cam element that interact with a protrusion on the dose counting ring, the pin shown in a downwards or normal-use position.

Figure 15 shows a close-up perspective cutaway view of the end-of-life lockout mechanism of the second embodiment.

Figure 16 shows a perspective view from one end of the cam element of the second embodiment of lockout mechanism.

Figure 17 shows a perspective view of the counting ring of the second embodiment, the ring having a protrusion that interacts with the cam at the end of life..

Figure 18 shows a perspective top cutaway view of the lower part of the lockout mechanism, showing the cam in the position in which it would be in normal use.

Figure 19 shows a perspective top cutaway view of the lower part of the lockout mechanism from the same angle as figure 18, showing the cam moved to a lockout position by being pushed by the protrusion.

Figure 20 shows a perspective cutaway view of the upper part of the inhaler and lockout mechanism of the second embodiment, a slot formed in the upper housing of the inhaler, a key bit on the pin that forms part of the lockout mechanism shown aligned with the slot so as to move into the slot to lock the mechanism.

Figure 21 shows a cutaway side perspective view of an inhaler having an end-of-life lockout mechanism according to a third embodiment of the invention, the inhaler similar in configuration and layout to the inhaler of the first embodiment, the end-of-life lockout mechanism in this embodiment comprising a pin having a lower end that comprises a toothed gearwheel, in use the teeth of the gearwheel interlocking with teeth on the lower edge of the counting ring, so that rotation of the counting ring 306 drives rotation of the pin, the upper part of the pin threaded except at the top of the pin, a nut threaded onto the upper part of the pin, the nut moving upwards and free of the threaded section at end of life to block the mechanism of the inhaler, the nut shown on the threaded section. Figure 22 shows a close-up cutaway perspective view of the toothed gearwheel interlocking with teeth on the lower edge of the counting ring.

Figure 23 shows a similar view of the mechanism of the third embodiment to figure 21 .

Figure 24 shows a cutaway to view of the mechanism of the third embodiment from close to the top of the mechanism, showing the nut in an upwards position and locking the inhaler from further use.

Figure 25 shows a cutaway side view of an inhaler having an end-of-life lockout mechanism according to a fourth embodiment of the invention, the inhaler similar in general or overall configuration and layout to the inhalers of the other embodiments, the end-of-life lockout mechanism in this embodiment comprising a spring-loaded pin that is held in a downwards position until it is released by the counting ring once the counting ring reaches an end-of-life position, the pin moving upwards once released so as to block the mechanism of the inhaler, the pin shown in the downwards position.

Figure 26 shows a cutaway side perspective view of the inhaler of figure 25.

Figure 27 shows a close-up perspective detail section side view of the pin mechanism of the inhaler of figures 25 and 26.

Figure 28 shows a top-down section view of the top of the pin of the end-of-life mechanism of figures 25-27, showing the location of the pin relative to the button of the inhaler.

Figure 29 shows a perspective view from one side of the section view of figure 28.

Figure 30 shows a close-up perspective detail section side view of the pin mechanism from a similar angle as figure 27.

Figure 31 shows a perspective section side view showing detail of the pin mechanism, and the position of the pin within the inhaler relative to the counting ring.

Figure 32 shows a perspective view of an embodiment of counting ring suitable for use with the fourth embodiment of lockout mechanism.

Figure 33 shows a perspective section view of the inhaler, showing detail of the counting ring and pin in contact at end-of-life, so that the counting ring will move the pin to release the pin.

DETAILED DESCRIPTION

General

In all of the embodiments described below, the inhalers have the following basic parts in common: a housing 1 formed from upper and lower parts 1a, 1 b: a mouthpiece 2 (that in the embodiments shown is integrally formed with the upper housing part 1 b, but which may be a separate item attached to the upper housing part); a cartridge 3; a spring 4; a spring cage 5; a counter ring 6, and a button 7. The inhaler also comprises a micropump that operates in use to deliver a dose of medicament from the cartridge to the mouthpiece.

The cartridge 3 is contained within the housing 1 , and is fl uid ically connected internally within the housing to the mouthpiece 2 so that in use doses of medicament can travel from the cartridge 3 to the mouthpiece for inhalation by a user when the inhaler is activated - that is, by a user pressing the button 7.

The inhaler is operated by twisting the upper and lower parts 1 a, 1 b of the housing 1 relative to one another to ‘cock’ the mechanism and prime the micropump. This action causes the counting ring 6 to incrementally rotate, and to index once. A user then presses the button 7 to release a dose of medicament via the mouthpiece.

After a set number of uses, the lockout mechanism/end-of-life mechanism activates to prevent further use of the inhaler, as outlined below.

Similar numbering is used for all of the embodiments described below, based on the general numbering outlined above - e.g. in the first embodiment the upper and lower parts are numbered 101a, 101 b, the mouthpiece is numbered 102, the cartridge 103, the spring 104, etc. In the second embodiment the upper and lower parts are numbered 201 a, 201b, the mouthpiece is number 202, the cartridge 203, the spring 204, etc.

Where directional signifiers such as ‘vertical’ or ‘horizontal’ are used, these have their normal meaning. However, when these are used with reference to the inhaler or any part thereof, this should be taken to mean ‘with the inhaler standing upright on a flat substantially horizontal surface’, and with the mouthpiece pointing upwards vertically.

First Embodiment

An inhaler having an end-of-life lockout mechanism according to a first embodiment is shown in figures 4 to 13.

As shown in figure 4, the inhaler 100 has a housing 101 formed from an upper part 101 a, and a lower part or base part 101 b. In this embodiment, the mouthpiece 102 is integrally formed with the upper housing part 101 b, and has an attachment hinge at one side for a lid (similar to that shown in figure 2).

The housing 101 encloses the internal elements of the inhaler such as the cartridge (not shown in figures 5-13), the spring and spring cage 104, 105, the counting ring 106, and the micropump. As shown in figure 5, the spring 104 is a coil spring that extends within the housing between the upper and lower parts, with the spring cage 105 located mostly within the upper part 101 b and extending around the upper part of the spring 104. The counting ring 106 comprises a ring-shaped element located so as to extend around the spring cage inside the upper housing part, the counting ring located towards the lower end of the upper housing part. The counting ring 106 in this embodiment has a toothed upper edge. A wormgear 108 is located in and connected to the housing so that the wormgear 108 interacts with the teeth of the counting ring 106. As noted above, in use the user ‘cocks’ or prepares the inhaler 100 for use by twisting the upper and lower parts 101a, 101 b of the housing 101 relative to one another, this twisting motion occurring around a central axis that runs substantially centrally, vertically, from the top to the bottom of the inhaler 100. The wormgear 108 is connected to the housing and located so that this relative rotational action causes the wormgear to rotate, which causes the counting ring 106 to rotate and to index once (that is, rotate around its central axis a fraction of the circumference of the ring 106, from an initial position to a second position, to make a count of ‘one dose’). This movement of the counting ring 106 takes place every time the relative rotational movement takes place, with the counting ring 106 moving in the same direction each time, so that there is incremental rotation of the counting ring 106. The counting ring 106 can be marked with numbers, and a window formed in the housing, so as to allow a user to see how many doses have been used and/or are remaining.

This twisting action also primes the micropump for delivery of the medicament from the cartridge to the mouthpiece. Once the inhaler has been prepared for use, a user then puts their mouth over the mouthpiece 102 and presses the button 107 to release a dose of medicament into their mouth via the mouthpiece.

As best shown with reference to figure 7, the counting ring 106 further comprises an extension 109 that extends downwards from the underside of the counting ring 106 at one point on the circumference. As the ring rotates, the extension 109 moves around the inner circumference of the housing, and will eventually come into contact with and interact with a pin 110 that is located in the upper housing part and which extends along the side of the upper housing part, outside the spring cage and counting ring. The axis of the pin 110 is substantially vertical and parallel to the overall longitudinal axis of the inhaler. The counting ring 106 and extension 109 together form a lockout activation element for the first embodiment.

The preferred embodiment of pin 110 is shown in figure 13. The pin 110 comprises an elongate main body 110a with a wider hollowed out base section 110b, the base section open at the lower end and adapted to in use contain a spring 114 and locate onto an upright extension 115 within the housing. The upper end of the pin 110 comprises a key bit 110c that extends from one side of the pin 110.

As shown in figure 13, an interference extension or interference cam 112 extends radially outwards from the base section 110b of the pin 110, aligned in use inwards into the inhaler. In use, with the pin 110 in position in the housing, the interference cam 112 is at the same vertical level within the inhaler as the extension 109 on the ring.

As shown in figures 10 and 11 , the key bit 110c is configured to fit through a slot 113 in the housing, the slot 113 formed in the housing towards the top end of the upper part 101 a. In normal use, the base of the pin 110 is located onto the upright extension 115 and pushed onto the spring 114, so that the spring is compressed. The starting position - that is, before the inhaler has been used - of the upper end of the pin 110 is out of alignment with the slot 113 and for the key bit 110c to be pushed against the housing at the side of the slot 113, so that the pin is retained in the lower position with the spring compressed.

With repeated uses of the inhaler, the counting ring 106 rotates incrementally, and the extension 109 moves, rotating with the rest of the counting ring. At the point where only one or two doses are due to be delivered by the inhaler, the front or leading side of the extension 109 contacts the side of the interference cam 112. With delivery of the last dose, the extension 109 pushes against the interference cam 112 so that the pin 110 rotates. This rotation causes the key bit 110c to align with the slot 113. When the key bit 110c is aligned with the slot 113, the compressed spring 114 uncompresses to cause the pin to move upwards (that is, linearly in a direction substantially aligned with the main longitudinal axis of the inhaler, in the direction of the mouthpiece) to a ‘lock’ or ‘end of life’ position, the key bit 110c locating into the slot 113 as shown in figure 11 to prevent further rotation of the counting ring.

As the key bit 110c is now located in the slot, and as the pin 110 is a solid, rigid item, the pin 110 will remain in this position. As best shown with reference to figures 10 and 11 , the button 107 can in normal use be pressed inwards into the housing from an outwards position so as to dispense a dose from the inhaler or to release a dose of medicament, with the edge of the button passing over the top of the pin 110. However, once the pin 110 has moved upwards to the ‘lock’ or ‘end of life’ position, the pin 110 in the upwards position blocks the button in the outwards position and it cannot be pushed into the housing, thus preventing further use of the inhaler. That is, the button is blocked in the outwards position by the blocking element. As well as this, the pin 110 is no longer in contact with the extension 109 on the ring - the lower or base end of the pin has moved upwards so that it is now above the top of the extension 109. This helps to ensure that a user cannot keep manipulating the inhaler mechanism in order to create a ‘false’ reset.

It can be seen that the pin 110 forms a blocking element, and that this blocking element moves from a first or first set of positions (the normal in use positions where the pin is pushed onto the spring in a downwards starting position) to a second position, where the pin 110 in the upwards position blocks the button into an outwards position where the button cannot be pressed inwards. This occurs when the upper end of the pin 110 is out of alignment with the slot 113 and the key bit 110c is pushed against the housing at the side of the slot 113, so that it is in alignment with the slot 113 and can move upwards, pushed by the spring 114.

Second Embodiment

An inhaler having an end-of-life lockout mechanism according to a second embodiment is shown in figures 14 to 20.

The inhaler 200 of this embodiment has substantially the same elements as the inhaler of the first embodiment, and operates in a substantially similar manner to deliver medicament to a user. The same or similar elements are given similar numbering in the manner outlined above.

The end-of-life lockout mechanism of the second embodiment operates in a similar manner to that of the first embodiment - a pin 210 comprises a key bit 210c that, at end of life, moves into alignment with a slot 213. A spring 214 is held in tension by the pin 210, and unloads/uncompresses to push the key bit 210c through the slot 213 as the key bit 210c comes into alignment with the slot. The pin 210 then moves linearly upwards so as to block operation of a button 207. That is, the button 207 can in normal use be pressed inwards into the housing from an outwards position so as to dispense a dose from the inhaler , but in the ‘lock’ or ‘end of life’ position, the pin 210 in the upwards position blocks the button 207 in the outwards position, and the button cannot be pushed into the housing, thus preventing further use of the inhaler. That is, the button is blocked in the outwards position by the blocking element.

However, in this embodiment, the end-of-life lockout mechanism comprises the pin 210 and a cam element 220. As shown in figures 14 and 15, the main body of the pin 210 extends along the side of the inhaler 200. The cam element 220 is located in the housing at the lower end of the pin 210. The cam element is configured so that in use, a spring 214 is kept in compression at the lower end of the pin, pressing upwards against the lower end of the pin. The cam element is hollow, with the lower end of the spring locating into the top end of the cam element, and the spring locating into the lower end.

In this embodiment, as shown in figure 17, the counting ring 206 has a protrusion 209 extending radially outwards on the circumference of the ring 206. The counting ring 206 and protrusion 209 together comprise a lockout activation element for the second embodiment.

The cam element 220 has a lobe 220a that extends from the main body of the cam element. In normal use, the cam element is aligned as shown in figure 18. With repeated uses of the inhaler, the counting ring 206 rotates incrementally, and the extension 209 moves with the counting ring. At the point where only one or two doses are due to be delivered by the inhaler, the front or leading side of the extension 209 contacts the side of the lobe 220a. With the last dose, the extension 209 pushes on the lobe 220a so that it moves to the position shown in figure 18. This causes associated rotation of the pin 210. As shown in figure 20, there is a slot 213 formed in the upper housing. Rotation of the pin 210 causes the key bit 210c to align with the slot 213, which allows the spring 214 to decompress to push the pin 210 upwards towards the mouthpiece end of the inhaler. The upper end of the pin will then be in a position where it blocks operation of the button 207 - the button is locked into an ouwards positions and cannot be pushed inwards. As for the first embodiment as described above, the pin 210 is no longer in contact with the extension 209 on the ring - the lower or base end of the ring has moved upwards so that it is now above the top of the extension 209. This helps to ensure that a user cannot keep manipulating the inhaler mechanism in order to create a ‘false’ reset.

It can be seen that in this embodiment, the pin 210 forms a blocking element.

Third Embodiment

An inhaler having an end-of-life lockout mechanism according to a third embodiment is shown in figures

21 to 24.

The inhaler 300 of this embodiment has substantially the same elements as the inhaler of the first and second embodiments, and operates in a substantially similar manner to deliver medicament to a user. The same or similar elements are given similar numbering in the manner outlined above.

In this embodiment, a pin 310 extends along the side of the inhaler as shown in figure 21 . The pin in this embodiment has a lower end that comprises a toothed gearwheel 321 . In use, the teeth of the gearwheel 321 interlock with teeth on the lower edge of the counting ring 306, so that rotation of the counting ring 306 drives rotation of the pin 310. The upper part of the pin is threaded with a thread 323, except at the top of the pin, which is smooth and unthreaded. In use, a nut 322 is threaded onto the upper part of the pin, and positioned at or close to the bottom of the threaded part (that is, at that end of the pin towards the base of the inhaler). A coil spring 314 is located on the pin 310 so that when the nut is screwed onto the pin, the spring 314 is placed in compression, with its upper end pressing against the underside of the nut 322. The pin and nut are configured so that the length of the unthreaded section is slightly larger than the height of the nut. In this third embodiment, the counting ring 306 and pin 310 form a lockout activation element.

In use, the inhaler is operated in a similar manner to that outlined above - that is, a user ‘cocks’ or prepares the inhaler for use by twisting the upper and lower parts of the housing relative to one another. This causes an incremental or indexing rotation of the counting ring. As the counting ring 306 rotates incrementally, this causes rotation of the pin 310. As the pin 310 rotates, the nut 322 moves up the pin, driven by the thread 323. As a user ‘cocks’ or prepares the inhaler 300 for use by twisting the upper and lower parts of the housing relative to one another for the final dose, the nut reaches the end of the threaded section, and ‘jumps’ off the end of the pin, driven upwards by the spring. It can be seen that in this embodiment, the nut 322 forms a blocking element.

That is, the button 307 can in normal use be pressed inwards into the housing from an outwards position so as to dispense a dose from the inhaler , but in the ‘lock’ or ‘end of life’ position, the nut 322 has been driven upwards by the spring so as to now be in a position where the nut 322 blocks the button 307 in the outwards position, and the button cannot be pushed into the housing, thus preventing further use of the inhaler. That is, the button is blocked in the outwards position by the blocking element - the nut 322.

Fourth Embodiment

An inhaler having an end-of-life lockout mechanism according to a fourth embodiment is shown in figures 25 to 33.

As for the previous embodiments, and as shown in figures 25 and 26, the inhaler 400 has a housing 401 formed from an upper part 401a, and a lower part or base part 401 b, with the mouthpiece 402 integrally formed with the upper housing part 401b.

The housing 401 encloses the internal elements of the inhaler, including a counting ring 406 (shown by itself in figure 32). The same as for the previous embodiments, the counting ring 406 comprises a ringshaped element with a toothed upper edge that in use is located inside the upper housing part 401a, the counting ring located towards the lower end of the upper housing part and extending around the inside of the upper housing part 401a. The toothed upper edge of the counting ring engages in use with a wormgear 408.

In use the user ‘cocks’ or prepares the inhaler 400 for use by twisting the upper and lower parts 401a, 401 b of the housing 401 relative to one another, this twisting motion occurring around a central axis that runs substantially centrally, vertically, from the top to the bottom of the inhaler 400. The wormgear 408 is connected to the housing and located so that this relative rotational action causes the wormgear to rotate, which causes the counting ring 406 to rotate and to index once (that is, rotate around its central axis a fraction of the circumference of the ring 406, from an initial position to a second position, to make a count of ‘one dose’). This movement of the counting ring 406 takes place every time the relative rotational movement takes place, with the counting ring 406 moving in the same direction each time, so that there is incremental rotation of the counting ring 406.

As shown in figure 32, the counting ring 406 further comprises an extension or arm 409 that extends upwards from the counting ring 406 at one point on the circumference. As the ring rotates, the arm 409 moves around the inner circumference of the housing, and will eventually come into contact and interact with peg or pin 410, which is described below. In this fourth embodiment, the counting ring 406 and peg 410 form a lockout activation element.

The preferred embodiment of peg 410 is best shown in figures 27, 30, and 31 . As shown in these figures, the upper housing part 401 a is configured to receive the pin 410 in a recess extending from one side of the upper housing part 401a, so that the peg 410 is aligned substantially parallel with the axis of the inhaler (the axis around which the upper and lower housing parts are rotated). The peg can move within the recess between an upwards or upper position and a downwards or lower position.

The peg 410 comprises an elongate main body 410a, with a hooked lower end 410b. An extension or protrusion 410c extends outwards from the main body 410a towards the upper end of the main body, aligned in substantially the same direction as the hooked lower end. In the lower or first position, the top surface of the protrusion 410c locates against part of the housing, to hold the peg 410 in place.

A passage 425 is formed in the upper end of the peg 410, the passage 425 extending substantially axially into the peg from the top of the peg. In use, the peg 410 locates onto a receiving extension 430 that forms part of the upper part 401a within the recess in the upper housing part 401a, extending down from the top of the recess, so that the peg 410 is held in position, but can rotate on the receiving extension 430. When the peg 410 is in the lower position (as shown in figure 27 and 30), the passage extends below the lower end of the receiving extension 430, so that there is room within the passage to allow the peg 410 to move upwards on the receiving extension.

The upper end of the peg 410 is formed so as to have a blocking extension 41 Od, that extends inwards from the top end of the peg. When the peg 410 is in the downwards position, the button 407 can move over the top of the blocking extension 41 Od, as best shown with reference to figures 28 and 29. When the peg 410 is in the upwards position, the blocking extension 41 Od is positioned directly behind the button 407 so as to prevent this being depressed or pushed inwards to active the inhaler. That is, the button 407 can in normal use be pressed inwards into the housing from an outwards position so as to dispense a dose from the inhaler , but in the ‘lock’ or ‘end of life’ position, the blocking extension 41 Od on peg 410 is in the upwards position, and blocks the button 407 in the outwards position. The button 407 cannot be pushed into the housing, thus preventing further use of the inhaler. That is, the button is blocked in the outwards position by the blocking element.

As well as this, the peg 410 is no longer in contact with the extension 409 on the ring - the lower or base end of the peg has moved upwards so that it is now above the top of the extension 409. This helps to ensure that a user cannot keep manipulating the inhaler mechanism in order to create a ‘false’ reset.

A coil spring 414 is positioned around the central main body part of the peg 410. As shown in the figures, the top inner side of the coil spring 414 locates against the underside of the protrusion 410c. The top outer side of the coil spring is free.

The lower end of the coil spring 414 locates against a shelf 436 within the upper part 401 a. The lower end of the peg 410 extends through an aperture 437 within the shelf, with the hooked lower end 410b hooking onto the lower side of the shelf 436. The aperture 437 is large enough that the lower end and main body of the peg 410, including the hooked end 410b, can fit through the aperture.

With the hooked lower end 410b hooked onto the shelf, the peg 410 is retained in a downwards position, with the coil spring 414 in compression. The asymmetric arrangement at the top of the peg 410 (with the inner side of the spring 414 retained downwards by the protrusion 410c, and the outer side moving freely upwards) places a leverage force on the peg 410 that tends to push against the peg 410 to push the hooked lower end 410b into engagement with the shelf 436 - that is, to push the hooked end 410b inwards.

As the counting ring 406 rotates incrementally in use, at the end of life, the arm 409 on the counting ring comes into contact with the hooked lower end 410b, the lower end 410b also functioning as an interference extension or cam. At end of life - the final dose - the arm 409 pushes the hooked lower end 410b out of engagement with the shelf 436. As the lower end is no longer retained by the shelf, the coil spring 414 un-compresses to push the peg 410 upwards, the blocking extension 410d moving upwards with the rest of the peg 410, so that the blocking extension 41 Od ends up behind the rear of the button 407, to prevent the button 407 from being depressed by a user. It can be seen that in this embodiment, the peg 410 forms a blocking element.

Claims

1. An end-of-life lockout mechanism for an inhaler of the type that comprises a mechanical button operable by a user pressing the button inwards from an outwards position so as to dispense a dose from the inhaler, the end-of-life lockout mechanism comprising: a blocking element configured to locate within the housing of the inhaler, the blocking element and housing further configured so that the blocking element can move from a first position or first set of positions within the housing where operation of the inhaler takes place normally, to a second position; a lockout activation element configured to locate within the external housing of the inhaler, the lockout activation element configured so that each single operation of the inhaler causes the lockout activation element to move incrementally within the housing, until, after a plurality of single operations, the lockout activation element reaches a pre-set point and causes the blocking element to move to the second position; characterised in that the lockout activation element and blocking element are mutually configured to locate within the external housing of the inhaler so that in the second position the button is blocked in the outwards position by the blocking element

2. An end-of-life lockout mechanism as claimed in claim 1 wherein the lockout activation element activation element comprises a ring.

3. An end-of-life lockout mechanism as claimed in claim 2 wherein the ring comprises gear teeth.

4. An end-of-life lockout mechanism as claimed in claim 2 or claim 3 wherein the ring comprises an extension, extending outwards from the ring.

5. An end-of-life lockout mechanism as claimed in claim 4 further comprising a cam element configured to interact with the activation element and to connect with the blocking element to cause the blocking element to move to the second position at the pre-set point.

6. An end-of-life lockout mechanism as claimed in claim 4 or claim 5 wherein the extension extends outwards from the ring substantially axially.

7. An end-of-life lockout mechanism as claimed in claim 4 or claim 5 wherein the extension extends outwards from the ring substantially circumferentially.

8. An end-of-life lockout mechanism as claimed in any one of claims 1 to 7 wherein the blocking element comprises a pin having an elongate main body and a key bit extending from the main body.

9. An end-of-life lockout mechanism as claimed in claim 3 wherein the blocking element comprises a pin having an elongate main body, one end of the main body formed with gear teeth configured to interact with the ring gear teeth in use so as to rotate the main body as the ring rotates, the blocking element further comprising a moving element locating in use onto the main body, the main body and moving element mutually configured so that the moving element will move along the main body as the main body rotates, from the first position or positions to the second position.

10. An end-of-life lockout mechanism as claimed in any one of claims 1 to 6 wherein the blocking element comprises a hooked lower end, the housing and hooked lower end configured for mutual engagement in the first position or first set of positions.

11. An end-of-life lockout mechanism as claimed in claim 10 wherein the blocking element further comprises a protrusion extending outwards from the main body substantially towards the upper end ofhe main body, aligned in substantially the same direction as the hooked lower end.

12. An end-of-life lockout mechanism as claimed in any one of claims 1 to 11 wherein the blocking mechanism further comprises a spring configured to operate to cause the blocking mechanism to moveo the second position at the pre-set point.