Title: Dosing device for dispensing a viscous substance,- for instance an antiseptic fluid, and container for such dosing device
The invention relates to a dosing device for dispensing a viscous substance, for instance an antiseptic fluid, and comprising a housing in which a compressible container with viscous substance, a dosing pump of the atomizer type for withdrawing viscous substance from the container, and a control member for the dosing pump movable with respect to the housing and reaching to outside the housing are accommodated, which dosing pump comprises a housing part stationary with respect to the housing and a channel part movable by the control member with respect to the housing part. The invention also relates to a container for such dosing device.
A dosing device of the above type is known from WO 96/21387. The compressible container disclosed therein comprises a multipart valve to be brought by a probe of the. dosing pump from a closed position to an open position, and conversely, thus preventing contamination of the dosing device when placing or removing the container. When opening the valve, a movable part thereof is pressed out of a transport snap closure by the probe of the dosing pump, which probe needs to be coupled with the movable part through a further snap closure so as to close the valve and restore the transport snap closure again upon removal of the container. This double snap action sets high standards for the required tolerances between the dosing device, at least the probe thereof, and diverse containers which should successively cooperate with the dosing device in a correct manner. Especially the closure of the container is very tolerance sensitive owing to the fact that the snap connection between probe and movable part is not allowed to break before the transport snap connection is restored, because otherwise leakage is unavoidable.
Furthermore, in the open position of the valve the probe must sealingly connect to the valve so as to prevent leakage during use, which still increases the tolerance problems and the resistance during closure of the valve, thus reducing the leakage protection.
The object of the invention is to provide a dosing device of the type described in the opening paragraph, which is substantially less tolerance sensitive and, partly as a result, gives more protection against leakage. This is achieved according to the invention, when the dosing device is undetachably connected with the compressible container in the form of a flexible bag and is provided with a coupling member, with which the housing part is detachably fixed in the housing. By directly mounting the dosing pump on the container, this connection is made completely tolerance insensitive and leakage proof, while fixing the housing part in the housing by means of the coupling member ensures a correct effect of the control member on the channel part to introduce the pump performance. Thus not only any leakage possibility in the connection between container and dosing pump is very effectively prevented, but placing and removing a container in the dosing device is simplified and facilitated as well.
It is observed that at first sight it seems disadvantageous from a viewpoint of cost to supply a dosing pump with each container. However, the dosing pump used may be a simple atomizer pump made as a mass-produced article, as used on spray cans, perfume bottles, and the like. Characteristic of such a pump is the use in an upright position with the pump at the top of the rigid container, while viscous substance atomized by the pump is replaced by air which can flow into the pump by aeration means and the dispensing channel of the pump is connected with a hose reaching into the bottom of the upright container. Inverted use of such a dosing device leads to the pump becoming ineffective and to leakage via the aeration means. Such
leakage can be prevented by closing or omitting the aeration means, which is rendered possible by the use of a compressible container which prevents vacuum drawing and can advantageously be designed as a simple flexible bag to be sealed to the dosing pump. Because such an atomizer pump is a mass-produced article, the cost will hardly be higher as compared with a specific dosing pump incorporated into the housing of the dosing device; the more so as a precision- requiring, separate closing and connecting valve for the container can be omitted. Moreover, from the viewpoint of hygiene placing a new dosing pump with each container has the advantage of a decreased risk of leakage via a worn dosing pump.
By taking the measures according to the invention, a piece of cleaning material, for instance toilet paper, can be pressed from below against the pump control member for wetting by means of pumping with viscous substance, more in particular an antiseptic fluid, after which a toilet seat can be disinfected quickly and hygienically. When according to a further embodiment of the invention the housing part and the channel part are arranged concentrically with respect to each other and the coupling member is a flange part arranged on the housing part concentrically with respect to the housing part and the channel part, which flange part is slid into a corresponding slot in the housing, the container with dosing pump can be placed in the housing with a single slid-in movement in such a manner that the dosing pump is fixed ready for use at least in the pump moving direction of the channel part. The dosing pump is controlled by longitudinally moving the channel part with respect to the housing part, which channel part is then also effective as control member. For ease of use, however, it is preferred according to a further embodiment of the invention that the control member has the form of a cap with a central opening surrounded by a conical wall which clampingly engages the outer wall of the channel part, so
that by pressing the cap the dosing pump is controlled and a measured amount of viscous fluid is dispensed via the central opening in the cap. To prevent the cap from being pulled loose or pressed excessively, it is further preferred that the control member is slidable between two end positions defined by housing parts. Such a control member exchangeable with respect to the dosing pump and movably arranged in the housing may have any desired form, that is to say it may be optimally adapted to manual control for operating the dosing pump .
To enable easy and reliable arrangement of a container located in the housing with its dosing pump at the bottom, it is preferred that the compressible container is suspended in the form of a bag to suspension means arranged in the housing, for instance two hook-shaped members which, arranged through openings, can reach into ears formed at the bag.
The invention also relates to a compressible container for viscous fluid and intended for use in a dosing device as described above. More in particular, this container consists of a flexible bag for receiving a supply of viscous substance, such as an antiseptic fluid, and which compressible container is designed in the form of a flexible bag and is provided with a dosing pump undetachably connected therewith, which comprises a housing part and a channel part, while the housing part is provided with a coupling member. The dosing pump is preferably of the generally known atomizer type for spray cans, perfume bottles, and the like, while the conventional aeration means are closed or omitted. With reference to an illustrative embodiment shown in the drawing by way of example only, the dosing device according to the invention will now be explained in further detail. In the drawing:
Fig. 1 is a side view of a dosing device according to the invention with omission of a cover;
Fig. 2 is a front view of Fig. 1; and
Fig. 3 is an enlarged cross-sectional view of a dosing pump.
The dosing device shown in Figs. 1 and 2 comprises a wall mounting part 1 for suspending, by means of hooks 2 mounted on a head part la, a flexible bag 3 filled with a viscous substance, in the present case an antiseptic cleaning fluid. At the bottom the flexible bag 3 has a dosing pump 4 rigidly and sealingly connected therewith, which dosing pump 4 will be discussed in further detail with reference to Fig. 3.
The dosing pump 4 comprises an open tubular housing part 5 with a first cross-section 5a, a second, smaller cross-section 5b and a third, still smaller cross-section 5c, while at the transition from the second cross-section 5b to the third cross-section 5c a seat is formed for a ball 6, which is pressed towards the seat by means of a spring 7. On the side facing away from the ball 6 the spring 7 is clamped on a projection 8 on a flange 9 at the end of a piston rod 10, which is provided with a longitudinal channel 11 merging into a transverse channel 12. Furthermore, the piston rod 10 is provided with a ring flange 13, on which a spring 14 is supported with one end. The other end of the spring 14 presses against a piston 15, which, on the one hand, is slide- fit into the first cross-section 5a of the open tubular housing part 5 and, on the other hand, can slide over the piston rod 10, while the spring 14 presses the piston 15, until it strikes the flange 9, 'so that the piston 15 closes the transverse channel 12. Furthermore, at the first cross- section 5a the open tubular housing part 5 is provided on its exterior with a supporting flange 16.
The supporting flange 16 engages in a half ring groove 17, which forms a protuberance of a half cylindrical recess 18 arranged in foot part lb of the wall mounting part 1 and partly receiving the open tubular housing part 5 as well as a slid-over bush part 19 of a control cap 20 with a limiting flange 21. The bush part is internally provided,
in a manner not shown, with a sleeve part, which clampingly engages around the piston rod 10, receives support from the ring flange 13 and is provided with a central opening discharging into a central recess, likewise not shown, in the control cap 20, the arrangement being such that antiseptic cleaning fluid leaving the longitudinal channel 11 can fall on a cleaning material, for instance a piece of toilet paper, pressed against the bottom of the control cap 20.
To control the dosing pump 4 by means of the control cap 20, the latter is vertically slidably received in the foot part lb. To this end, adjoining the half cylindrical recess 18, the foot part lb has a second half cylindrical recess 22 with a radius exceeding that of the limiting flange 21. The second half cylindrical recess 22 adjoins a third half cylindrical recess 23 with a diameter slightly exceeding that of the control cap 20. The height of the second half cylindrical recess 22 is chosen such that the limiting flange can vertically move over the desired distance for control of the dosing pump 4. The height of the third half cylindrical' recess 23 is chosen such that the control cap 20 projects below the foot part lb over a distance sufficient to enable control of the dosing pump 4 by manually pushing the control cap 20 upwardly. To prevent the control cap 20, when pushed upwardly, from tilting, as the limiting flange 21 strikes the upper side of the second half cylindrical recess 22, two triangular stops 24 are provided. Moreover, a cover, not shown, may be provided with one or more projections, which, when the cover is closed, make a vertical line contact with the bush part 19, so that it can vertically but not perpendicularly move. Such a cover may, for instance, be hingedly attached to the foot part lb and further be provided with a hinged locking hook, which may engage in a recess 25 in the head part la.
The operation of the dosing device shown in the figures is as follows.
By manually pushing a piece of cleaning material against the control cap 20, the control cap 20 and thus the piston rod 10 of the dosing pump 4 can be pushed upwardly, seen in Fig. 3. Starting from a filled dosing chamber, that is to say the space between the piston 15 and the ball 6, the upward movement of the piston rod 10 will press the ball 6 against its seat via the spring 7, and an upwardly pushing force will be imposed via the spring 14 on the piston 15. Because the dosing chamber is filled with fluid that cannot be pushed away, the piston 15 will remain in position at the start of the upward movement of the piston rod 10, while the spring 14 is compressed. Thus the piston rod 10 moves with respect to the piston 15, so that the access to the transverse channel 12 is released. The fluid can now be pressed out of the dosing chamber via the channels 12 and 11 through movement of the piston 15, together with the piston rod 10, and sprayed onto the piece of cleaning material, with which the control cap 20 is pushed upwardly.
When removing the wetted piece of cleaning material ' to clean a toilet seat therewith, the spring 7 will push back the piston rod 10, and the spring 14 will return the piston 15 to the position closing the access to the transverse channel 12. During the return movement the reduced pressure thereby created in the dosing chamber will withdraw the ball 6 from its seat, so that new fluid is sucked in from the bag 3, the interior of which is in open communication with the cross-section 5c of the dosing pump 4. The decrease in volume thereby caused in the bag 3 is compensated by the contraction of the flexible bag, so that no vacuum can be drawn therein, which would make the pump performance ineffective. Because the connection between the environment and the interior of the bag is closed at the transverse channel 12 by the piston 15, any leakage is effectively prevented. Moreover, a further sealing is present at the ball 6. In known atomizer dosing pumps, which are used invertedly, that is to say with the free end of the
longitudinal channel 11 at the top and the glass or rigid plastic fluid container at the bottom of the dosing pump', a deaeration channel is present, as very schematically shown in Fig. 3 by a dashed line. On the one hand, this channel is in open communication with the interior of the container and, on the other hand, in the rest position of the dosing pump this channel is just closed by the piston of the dosing pump. As soon as the piston moves when the dosing pump is operated, the access to the channel will be released. During inverted use, as shown in Fig. 3, such a construction will directly give rise to fluid leaking away, which is less important when the dosing pump is operated, because then the fluid leaking away falls on the piece of cleaning material. However, when the piston returns, the deaeration channel remains filled with fluid. On the one hand, this is detrimental to the supply of air to the container to prevent reduced pressure; on the other hand, this soon gives rise to leakage in the rest position of the dosing pump, i.e. when no cleaning material is present anymore to collect the fluid leaking away. By closing or omitting this deaeration channel and manufacturing the container from a flexible bag, this risk of leakage is eliminated without adversely affecting the correct performance of the dosing pump during the successive drainage of the container. It is further observed that during the normal use of such known dosing pumps no risk of leakage occurs, because the deaeration channel discharges into an air head at the top of the container and air is only present in this channel . The correct performance of the dosing pump is made certain by means of a hose which connects to the part with cross-section 5c and reaches to the bottom of the container, so that the drawing-in of fluid is always ensured. During the inverted use of the dosing pump in the present device according to the invention this hose will and may not be present . It is self-evident that within the scope of the invention as laid down in the annexed claims many further
modifications and variants are possible. Thus it will be clear that known atomizer dosing pumps may also be used, ' though while closing or sealing the deaeration channel. It is also possible to use, instead of the control cap shown in the drawing, a known spray can head with a lateral spray opening. Furthermore, the use of a swinging lever to subject the piston rod to the desired movement may be considered. Besides, the construction of the dosing pump, as shown in Fig. 3 and explained above, is given only by way of example. Any other type of dosing pump may also be used, for instance a dosing pump with an actuator atomizing the fluid, provided the deaeration of the container is closed or absent and the container consists of a flexible bag, that is to say a container offering no resistance to contraction, and the contents of which conform to the fluid volume.