GB2448112A

GB2448112A - Dispensing apparatus with dose counter

Info

Publication number: GB2448112A
Application number: GB0700821A
Authority: GB
Inventors: John Cattermole
Original assignee: Bespak PLC
Current assignee: Consort Medical PLC
Priority date: 2007-01-16
Filing date: 2007-01-16
Publication date: 2008-10-08
Anticipated expiration: 2027-01-16
Also published as: GB0700821D0; WO2008087369A1; GB2448112B

Abstract

Dispensing apparatus comprising a casing for housing a metering container, a counter member 30 comprising a series of teeth 36 and a series of indicator markings, and an actuator member reciprocally moveable relative to the counter member for actuating said metering container. The actuator member comprises a driver 56 for engaging on each reciprocal movement of the actuator member a driven tooth of the series of teeth of the counter member so as to advance the counter member in a first sense; wherein the dispensing apparatus further comprises a ramp 19b for deflecting the driver during the reciprocal movement of the actuator member to selectively engage the driver with the series of teeth of the counter member for only a portion of the reciprocal movement.

Description

IMPROVEMENTS IN OR RELATING TO DISPENSING APPARATUS

The current invention relates to improvements in or relating to dispensing apparatus, and in particular an improved design of dose counter for providing a reliable indication of the number of doses dispensed from or remaining in a dispensing container. The dose counter may be used in a variety of apparatus but finds particular application in devices used for dispensing pharmaceutical compositions either nasally, by inhalation or sublingually.

It is known to provide dispensing apparatus with a dose counter in order to provide an indication of the number of doses dispensed from or remaining in a dispensing container.

It is also known to use annular counter members as part of a dose counter. Typically, the annular counter members are provided with indicator markings in the form of letters or numerals and the dose counter operates to urge the annular counter members to rotate incrementally as the dispensing apparatus is activated. Where a dispensing apparatus is only envisaged to dispense a relatively small number of doses then a dose counter may comprise a single annular counter member. However, where dispensing apparatus is required to dispense a relatively large number of doses then it is typically necessary to provide a plurality of annular counter members and to provide a mechanism to interljnk the annular counter members. For example, it is known to provide two annular counter members where a first annular counter member provides an indication of the number of units' of doses dispensed and a second annular counter member provides an indication of the number of tens' of doses dispensed. A disadvantage with such dose counters is that they are inherently more complicated than counters containing only a single annular counter member and are therefore more liable to become jammed and are generally more expensive to manufacture and are less compact.

Accordingly, the present invention provides dispensing apparatus comprising: a casing for housing a metering container; a counter member comprising a series of teeth and a series of indicator markings; an actuator member reciprocally moveable relative to the counter member for actuating said metering container; the actuator member comprising a driver for engaging on each reciprocal movement of the actuator member a driven tooth of the series of teeth of the counter member so as to advance the counter member in a first sense; wherein the dispensing apparatus further comprises a ramp for deflecting the driver during the reciprocal movement of the actuator member to selectively engage the driver with the series of teeth of the counter member for only a portion of the reciprocal movement.

An advantage of the dispensing apparatus of the present invention is that the use of a ramp for deflecting the driver allows for the counter member to be provided with teeth which are more closely arranged relative to one another without any danger of the driver engaging two teeth on a single actuation by coming into driving engagement with a subsequent or neighbouring tooth of the series of teeth to the driven tooth for that actuation. This allows for the counter member to be provided with a greater number of teeth around its circumference thereby allowing a single counter member to be used to provide an indicator for a greater number of doses. Alternatively, the dimensions of the teeth may be made smaller whilst maintaining the same length of

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stroke for the actuator member. Reducing the size of the teeth has the consequence that the commit' point -that is the point during the stroke of the actuator member that the counter is Committed to advancing by one increment -is reached earlier in the stroke of the actuator member. This reduces the chances that the counter will undercount by not actuating when the metering container is actuated.

A further advantage of this arrangement is that the dispensing apparatus is less complicated since it only preferably contains a single counter member in a preferred embodiment, this leading to an easier mechanism to manufacture.

Advantageously the selective engagement of the driver with the series of teeth of the counter member prevents engagement of the driver with a tooth of the series of teeth neighbouring the driven tooth.

Preferably reciprocal movement of the actuator member comprises a driven stroke in a first direction and a recovery stroke in a second, reverse, direction.

Preferably the actuator member is manually drivable during the driven stroke.

The dispensing apparatus may further comprise biasing means for moving the actuator member during the recovery stroke.

Preferably the driver is deflected by sliding along the ramp during a driven stroke.

Preferably the ramp is orientated to allow the driver to slide back along the ramp during a recovery stroke of the actuator member.

In one embodiment the ramp is configured to deflect the driver so as to move the driver out of engagement with the series of teeth of the counter member.

Preferably the driver is engageable with the driven tooth of the series of teeth of the counter member during a recovery stroke of the actuator member so as to advance the counter member.

Preferably the driver is deflected by sliding along the ramp during a driven stroke and the ramp is orientated to allow the driver to slide along the ramp back into engagement with the driven tooth of the series of teeth during a recovery stroke of the actuator member.

In another embodiment the ramp is configured to deflect the driver so as to move the driver into engagement with the series of teeth of the counter member.

Preferably the driver is engageable with the driven tooth of the series of teeth of the counter member during a driven stroke of the actuator member so as to advance the counter member.

Preferably the driver is deflected by sliding along the ramp during a driven stroke into engagement with the driven tooth of the series of teeth and the ramp is orientated to allow the driver to slide back along the ramp during a recovery stroke of the actuator member.

Preferably the counter member 15 an annular member.

Preferably the series of teeth of the counter member comprises a series of driven teeth.

Advantageously the counter member may comprise Only a single ring of driven teeth.

The counter member may comprise approximately 36 driven teeth.

Preferably the counter member additionally comprises a series of ratchet teeth.

Preferably the driven teeth are radially outside the ratchet teeth.

Preferably the apparatus further comprises a ratchet for preventing movement of the counter member in a second sense.

The present invention also provides a dispensing apparatus as described above Combined with a metering container.

The dispensing apparatus may be for use in a pharmaceutical dispensing device, such as, for example, a pulmonary, nasal, or sub-lingual delivery device. The term pharmaceutical as used herein is intended to encompass any pharmaceutical, compound, composition, medicament, agent or product which can be delivered or administered to a human being or animal, for example pharmaceutjcajs, drugs, biological and medicinal products. Examples include antiallergics, analgesics, antibodies, vaccines, bronchodjiators, antihjstamjnes, therapeutic proteins and peptides, antitussives, anginal preparations, antibiotics, anti-inflammatory preparations, hormones, or sulfonamides, such as, for example, a vasoconstrjctjve amine, an enzyme, an alkaloid, or a steroid, including combinations of two or more thereof. In particular, examples include isoproterenol [alpha-(isopropylaminomethyl) Protocatechuy]. alcohol], phenylephrjne, phenylpropanolamjne, glucagon, insulin, DNAse, adrenochrome, trypsin, epinephrine, ephedrine, narcotine, codeine, atropirie, heparin, morphine, dihydromorphjnone, ergotamirie, scopolamine, methapyrilene, cyanocobalamin, terbutaline, rimiterol, salbutamol, flunisoljde, coichicine, pirbuterol, beclomethasone, orciprenaline, fentanyl, and diarnorphirie, streptomycin, penicillin, procaine penicillin, tetracycline, chiorotetracycline and hydroxytetracycline adrenocorticotropic hormone and adrenocortical hormones, such as cortisone, hydrocortisone, hydrocortjsone acetate and prednisolone, insulin, croinolyn sodium, and niometasone, including combinations of two or more thereof.

The pharmaceutical may be used as either the free base or as one or more salts conventional in the art, such as, for example, acetate, benzenesulphonate benzoate, bircarbonate, bitartrate, bromide, calcium edetate, camsylate, carbonate, chloride, citrate, dihydrochlorje, edetate, edisylate, estolate, esylate, fumarate, fluceptate, gluconate, glutamate, glycolly1arsanja hexylresorcinat, hydrobromjde, hydrochloride, hydroxynaphthoate iodide, isethionate, lactate, lactobjonate, rnalate, maleate, Inandelate, mesylate, methylbromjde, methylnitrate, Inethylsuiphate, inucate, napsylate, nitrate, pamoate, (embonate), pantothenate, phosphate, diphosphate, polyga1acturona, salicylate, stearate, subacetate, succinate, sulphate, tannate, tartrate, and triethjodjde, including combinations of two or more thereof. Cationic salts may also be used, for example the alkali metals, e.g. Na and K, and animonjum salts and salts of amiries known in the art to be Pharmaceutically acceptable, for example glycine, ethylene diamine, choline, diethanolamine, triethanolamine, octadecylamine, diethylamine, triethylamine, l-amino-2-propanQ_ajfl0..._ (hydroxyn1ethy1)prop_, 3-diol, and 1-(3,4-dihydroxyphenyl) -2 isopropylaminoethanol The pharmaceutical will typically be one which is suitable for inhalation or to be taken nasally or sub-.

lingually and may be provided in any suitable form for this purpose, for example as a solution or powder suspension in a solvent or carrier liquid, for example ethanol, or isopropyl alcohol. Typical propellants are HFA134a, HFA227 and di-methyl ether.

The pharmaceutical may, for example, be one which is suitable for the treatment of asthma. Examples include salbutamol, beclomethasone, salmeterol, fluticasone, formoterol, terbutaline, sodium chromoglycate, budesonide and flunisolide, and physiologically acceptable salts (for example salbutamol sulphate, salmetero]. xinafoate, flutjcasone propionate, beclomethasone dipropionate, and terbutaljne sulphate), solvates and esters, including combinations of two or more thereof. Individual isomers such as, for example, R-salbutamol, may also be used. As will be appreciated, the pharmaceutical may comprise of one or more active ingredients, an example of which is flutjform, and may optionally be provided together with a suitable carrier, for example a liquid carrier. One or more surfactants may be included if desired.

The seals and gaskets (if present for connecting the.

valve to a container) of the valve present in the metering container may be formed from any suitable material having acceptable performance characteristics. Preferred examples include nitrile, EPDM and other thermoplastic elastomers, butyl and neoprene.

Other rigid components of the metering container and or dispensing apparatus, such as the valve body, chamber body, valve stem, housing, actuator member or chassis may be formed, for example, from polyester, nylon, acetal or similar. Alternative materials for the rigid components of the valve or apparatus include stainless steel, ceramics and glass.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a perspective view of a first embodiment of dispensing apparatus according to the present invention; Figure 2 is a perspective view of the dispensing apparatus of Figure 1, with some parts omitted or partially omitted to show hidden detail; Figure 3 is an exploded perspective view of the dispensing apparatus of Figure 1; Figure 4 is a perspective view of a Counting mechanism of the dispensing apparatus of Figure 1 with some parts partially omitted to show hidden detail; Figures 5a to 5c are cross-sectional views of the counting mechanism of Figure 4 showing the counting mechanism at various stages of actuation; and Figure 6 is a schematic view of a second embodiment of counting mechanism.

As shown generally in Figures 1 to 4, the dispensing apparatus 1 comprises a chassis 10, counter wheel 30, cover 40, actuator button housing 50, housing 70 and contains in use a metering container in the form of a pressurised dispensing container or vial 80.

The chassis 10 is preferably formed from a single moulding comprising a base 11 from which extends upwardly a front wall 14. The front wall 14 Comprises an upwardly extending face provided with a hub 15 for receiving the counter wheel 30. Further, the front wall 14 comprises a guiding structure 19 having two vertical portions 19a and 19c separated by a ramp 19b having an angled face 20, a ratchet 21 ending in a ratchet tooth 22 and a rear guide plate 18 as shown in particular in Figure 4. Further, a return arm 90 is located alongside and spaced from the guiding structure 19. The return arm 90 is a cantilever member fixed at its base to the chassis 10 and with a tooth 91 at its free end. The use of the return arm 90 and guiding structure 19 will be described below.

The counter wheel 30 comprises a single annular member having a central aperture 31. The counter wheel 30 comprises an outer face 32 on which can be provided a number of numerical indicators (not shown in the attached drawings) around its periphery and an inner face 33 on which is provided a series of teeth as best shown in Figures 4 and 5.

The teeth 35 comprise a circumferential array of radially outer teeth 36 and a circumferential array of radially inner teeth 37. Thirty-six teeth 36 may be provided. A gap, without a tooth, is provided at one position around the circumference to act as a counter wheel stop. The use of the teeth 35 will be described below.

The apparatus 1 is provided with a cover 40 which overlies the counter wheel 30. The cover 40 comprises an aperture window 42.

The housing 70 comprises a moulding in the form of a sleeve having side walls 74 and a front face containing a counter aperture 71. The bottom 73 of the housing is open as is the top 72.

The actuator button housing 50 also comprises a single moulding having a top surface 51, a rear wall 52, a front wall 53 and a cantjlevered member 54. The actuator button housing 50 is sized to be received as a sliding fit within -10 -the housing 70. The cantilevered member 54 extends away from the top 51 of the actuator button housing 50. A distal end 55 of the Cantilevered member 54 comprises a driving member in the form of a reverse-facing tooth 56 having a first angled face 57 and a second angled face 58 as best shown in Figure 5. The actuator button housing 51 also comprises a dispensing aperture 59.

The dispensing apparatus 1 is used for dispensing product from a vial 80 which is received within the apparatus 1 as shown in the exploded view of Figure 3.

Typically the vial 80 comprises a dispensing container from which extends a valve stem 81 over which lies an actuator button 82.

To assemble the apparatus 1, the vial 80 is first positioned on chassis 10 The counter wheel 30 is then located onto the hub 15 of the chassis 10. Next, a biasing spring 17 is positioned on the chassis 10 and the actuator button housing 50 is located onto the chassis such that the spring 17 spans between the chassis 10 and the actuator button 50. Then the housing 70 is located Onto the chassis and actuator button housing 50.

As can be seen from Figure 1, the top 5]. of the actuator button housing 50 protrudes from the open top 72 of the housing 70 and the counter wheel 30 is visible through the counter aperture 71. Finally, the cover 40 is assembled to the apparatus 1. When located, the cover 40 obscures the counter wheel 30 except for that part of the counter wheel visible through the window aperture 42 of the cover 40.

When assembled, as shown in Figure 1, it can be appreciated that the actuator button housing 50 is slidably movable relative to the housing 70 and chassis 10 with the -ii -spring 17 causing the actuator button 50 to be biased upwardly at rest.

Also, as can be most clearly seen in Figures 4 and 5, when assemj1ed the cantjlevered member 54 of the actuator button housing 50 is aligned with the guiding structure 19 of the chassis 10. Axial movement of the actuator button housing 50 brings the tooth 56 at the distal end 55 of the cantilevered member 54 into and out of engagement with the guiding structure 19 and ramp 19b as will be discussed in detail below. it can also be seen that the rear guide plate 18 provides a guiding means for helping to control the transverse movement of the cantilevered member 54 during use.

In use, in order to actuate the apparatus 1, a user depresses the actuator button housing 50 by applying finger pressure to the top 51. This causes the actuator button housing 50 to slide axially relative to the housing 70 and chassis 10 inwardly into the apparatus 1. The actuator button housing 50 is constrained to slide axially by sliding contact between the actuator button housing 50 and the housing 70. Axial inward movement of the actuator button housing 50 brings the underside of the top 51 of the actuator button housing 50 into contact with the actuator button 82 of the vial 80 causing the actuator button 82 and the valve stem 81 to move inwardly relative to the vial 80 so as to actuate the vial 80 and dispense a metered dose of product. The product is dispensed from the actuator button housing 82 as known in the art and is dispensed from the apparatus 1 via the dispensing aperture 59 of the actuator button housing 50. When the actuator button housing 50 is released the biasing spring 17 of the apparatus 1 causes the actuator button housing 50 to return to its initial Position -12 -by axial sliding movement relative to the housing 70. In turn, this allows the actuator button 82 and valve stem 81 of the vial 80 to return to the initial, unactuated, position.

According to the present invention at the same time as the vial being actuated the actuator button housing 50 causes the indicating device of the apparatus 1 to activate.

Figures 5a to 5c illustrate the various stages of actuation.

In Figure 5a the actuator button housing 50 has not yet been depressed. As can be seen, the tooth 56 of the cantj].evered member 54 is positioned such that the apex of the tooth 56 lies against the vertical portion 19a of the guiding structure 19 and the first angled face 57 lies in contact with one of the teeth 36 of the counter wheel 30 -for the purposes of the subsequent actuation described below this is the driven' tooth. Note, however, that in the rest position the tooth 56 does not have to lie in contact with the driven tooth 36 of the counter wheel 30. In other words, the apex of the tooth 56 may lie higher up the vertical portion 19a of the guiding structure 19 so that an initial gap exists between the carjtjlevered member 54 and the counter wheel 30.

Inward axial movement of the actuator button housing 50 causes the tooth 56 at the distal end 55 of the cantilevered member 54 to move relative to the counter wheel 30. The order of engagement and movement of the cantilevered member 54 and counter wheel 30 is as follows.

Downward movement of the cantilevered member 54 is such as to try and urge the counter wheel 30 to move in a clockwise direction when viewed in the orientation shown in Figure 5a. However, the engagement of the ratchet tooth 22 with the radially inner teeth 37 as shown in Figure 5a prevents any movement of the counter wheel 30 in this -13 -direction. As a consequence, the cantilevered member 54 is deflected slightly to allow the first angled face 57 to ride over the driven tooth 36. As the tooth 56 rides over the driven tooth 36 and passes the apex of the driven tooth it then recovers due to the inherent elasticity of. the cantilevered member 54 such that the apex of the tooth 56 is positioned vertically under' the driven tooth as shown in Figure 5b. This is the commit point at which the counter will register a count when the actuator button 50 is released.

Further downward movement of the cantilevered member 54 then brings the tooth 56 into contact with the angled face of the ramp 19b before the tooth 56 contacts the next radially outer tooth 36 of the counter wheel 30 neighbouring the driven tooth. (As an alternative an as shown in Figure 5b, the dimensions of the guiding structure 19 may be such that the tooth 56 has just come into contact with the ramp 19b at the commit point shown in Figure 5b.

The engagement with the ramp 19b causes the cantilevered member 54 to be deflected away from the counter wheel 30 as shown in Figure 5c allowing a full stroke of the actuator button housing 50 to take place without the risk of teeth 36 neighbouring the driven tooth being drivingly engaged by the cantilevered member 54 such that a double count might be registered. During the latter portion of the stroke (during which movement the metering container is actuated) the tooth 56 slides along the vertical portion 19c of the guiding structure 19. Deflection of the cantilevered member 54 also deflects the return arm 90 which creates a biasing force on the cantilevered member 54 urging the member back into a vertical position.

-14 -On release of the actuator button housing 50, the cantjlevered member 54 moves upwardly causing the tooth 56 to ride back up the vertical portion 19c and angled face 20 of the ramp 19b as the cantilevered member 54 recovers to its unstressed shape helped by the urging force of the return arm 90. This recovery movement causes the second angled face 58 to be brought back into a position vertically underneath the driven tooth, as shown in Figure 5b, so as to cause engagement with the underside of the driven tooth 36 which was first contacted by the tooth 56 at the position shown in Figure 5b. At this point there is positive engagement between the cantilevered member 54 and the counter wheel 30. Continuing upward movement of the actuator button housing 50 and cantilevered member 54 causes the tooth 56 to rotate the counter wheel 30 through one increment by engagement between the second angled face 58 and the underside of the driven tooth 36. At the same time as rotation of the counter wheel 30, the ratchet tooth 22 of the ratchet 21 is able to ride over the radially inner teeth 37 to engage the next tooth 37. This rotation causes the indicator display in the aperture window 42 to be incremented or decremented.

Once this rotation has taken place the apparatus 1 is back to is initial position whereby a further actuating stroke of the actuator button housing 50 can take place in the manner described above. Actuation of the counter mechanism can continue until the gap in the series of outer teeth 36 reaches the position for the next driven tooth. At this point the mechanism becomes non-rotatable as engagement between the cantilevered arm 54 and counter wheel 30 is no longer possible.

-15 -In an alternative embodiment shown in Figure 6 the counter wheel 30 and cantjlevered arm 54 are altered to provide rotation of the counter wheel during the downward, driven stroke of the actuator button 50. In this case, the guiding structure 19 acts to deflect the cantilevered arm 54 into engagement with the counter wheel teeth 36 during the stroke rather that disengaging the member from the teeth as in the first embodiment. The teeth 36 on the counter wheel are directed in a reverse direction to the first embodiment and the unstressed position of the cantjlevered member 54 is not in vertical alignment with the driven tooth 36. The tooth 56 of the Cantilevered member 54 rides along the left-hand side (as viewed in Figure 6) of the guiding structure 19 and the guiding structure 19 acts to deflect the cantilevered member towards the wheel 30 rather than away from it as the tooth 54 passes along the ramp section 19b.

In other aspects, however, operation of the apparatus is similar to that described in the first embodiment.

Claims

-16 -Claims: 1. Dispensing apparatus comprising: a casing for housing a

metering container; a counter member comprising a series of teeth and a series of indicator markings; an actuator member reciprocally moveable relative to the counter member for actuating said metering container; the actuator member comprising a driver for engaging on each reciprocal movement of the actuator member a driven tooth of the series of teeth of the counter member so as to advance the counter member in a first sense; wherein the dispensing apparatus further comprises a ramp for deflecting the driver during the reciprocal movement of the actuator member to selectively engage the driver with the series of teeth of the counter member for only a portion of the reciprocal movement.
2. Dispensing apparatus as claimed in claim 1 wherein the selective engagement of the driver with the series of teeth of the counter member prevents engagement of the driver with a tooth of the series of teeth neighbouring the driven tooth.
3. Dispensing apparatus as claimed in any preceding claim wherein reciprocal movement of the actuator member comprises a driven stroke in a first direction and a recovery stroke in a second, reverse, direction.
4. Dispensing apparatus as claimed in claim 3 wherein the actuator member is manually drivable during the driven stroke.

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5. Dispensing apparatus as claimed in claim 3 or claim 4 further comprising biasing means for moving the actuator member during the recovery stroke.
6. Dispensing apparatus as claimed in any preceding claim wherein the driver is deflected by sliding along the ramp during a driven stroke.
7. Dispensing apparatus as claimed in claim 6 wherein the ramp is orientated to allow the driver to slide back along the ramp during a recovery stroke of the actuator member.
8. Dispensing apparatus as claimed in any preceding claim wherein the ramp is configured to deflect the driver so as to move the driver out of engagement with the series of teeth of the counter member.
9. Dispensing apparatus as claimed in claim 8 wherein the driver is engageable with the driven tooth of the series of teeth of the counter member during a recovery stroke of the actuator member so as to advance the counter member.
10. Dispensing apparatus as claimed in claim 8 or claim 9 wherein the driver is deflected by sliding along the ramp during a driven stroke and the ramp is orientated to allow the driver to slide along the ramp back into engagement with the driven tooth of the series of teeth during a recovery stroke of the actuator member.
11. Dispensing apparatus as claimed in any of claims 1 to 7 wherein the ramp is configured to deflect the driver so as -18 -to move the driver into engagement with the series of teeth of the counter member.
12. Dispensing apparatus as claimed in claim 11 wherein the driver is engageable with the driven tooth of the series of teeth of the counter member during a driven stroke of the actuator member so as to advance the counter member.
13. Dispensing apparatus as claimed in claim 11 or claim 12 wherein the driver is deflected by sliding along the ramp during a driven stroke into engagement with the driven tooth of the series of teeth and the ramp is orientated to allow the driver to slide back along the ramp during a recovery stroke of the actuator member.
14. Dispensing apparatus as claimed in any preceding claim wherein the driver comprises a flexible member.
15. Dispensing apparatus as claimed in any preceding claim wherein the driver comprises a cantilevered arm depending from a body of the actuator member.
16. Dispensing apparatus as claimed in claim 15 wherein a distal end of the cantjlevered arm comprises a tooth for engaging the series of teeth on the counter member.
17. Dispensing apparatus as claimed in claim 16 wherein the tooth of the cantj.levered arm is reverse-directed relative to the series of teeth of the counter member.
18. Dispensing apparatus as claimed in any preceding claim wherein the counter member is an annular member.

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1.9 - 19. Dispensing apparatus as claimed in any preceding claim wherein the series of teeth of the counter member comprises a series of driven teeth.
20. Dispensing apparatus as claimed in claim 19 wherein the counter member comprises only a single ring of driven teeth.
21. Dispensing apparatus as claimed in claim 19 or claim 20 wherein the counter member comprises approximately 36 driven teeth.
22. Dispensing apparatus as claimed in any of claims 19 to 21 wherein the counter member additionally comprises a series of ratchet teeth.
23. Dispensing apparatus as claimed in claim 22 wherein the driven teeth are radially Outside the ratchet teeth.
24. Dispensing apparatus as claimed in any preceding claim further comprising a ratchet for preventing movement of the counter member in a second sense.
25. Dispensing apparatus as claimed in any preceding claim Combined with a metering container.
26. Dispensing apparatus substantially as hereinbefore described with reference to or as shown in the accompanying drawings.