Abstract:
The present invention provides dose counter for displaying a count indication of the number or quantity of doses dispensed from or remaining in a container associated, in use, with the dose counter, comprising an indicator member comprising dose indicia and a priming indicator for prompting a user to carry out one or more priming actuations of the container. The priming indicator is initially arranged to at least partially overly the indicator member to thereby at least partially obscure viewing of the dose indicia of the indicator member until the one or more priming actuations of the container have been completed. The priming indicator is movable after the one or more priming actuations have been completed into a disposition where it no longer obscures viewing of the dose indicia of the indicator member. The invention also provides a dispensing apparatus comprising the dose counter.

Description:
[0001]    The present disclosure relates to a dose counter and a dispensing apparatus incorporating such a dose counter. In one example it relates to dose counters incorporated in a pressurised metered dose inhaler or a pump. 
       BACKGROUND 
       [0002]    It has been recognised in the past that there is a benefit in providing accurate information to a user of dispensing apparatus, such as pressurised metered dose inhalers (pMDIs), concerning the quantity of doses delivered from, or remaining in, the dispensing apparatus. Without such information, there is a risk that a user may be unaware that the dispensing container of the dispensing apparatus is empty or close to empty. This is a particular problem where the dispensing apparatus is for use in delivering medicinal compounds for the treatment of chronic or acute symptoms, for example, as in the case of a pMDI used for treating conditions such as asthma. 
         [0003]    A pMDI typically comprises a pressurised dispensing container that is received in an actuator housing. The actuator housing will comprise an outlet through which substance can be dispensed. The outlet will typically be adapted for oral, nasal or sub-lingual delivery of the substance. The pressurised dispensing container typically comprises a canister which defines a storage volume for the substance to be dispensed, wherein an open end of the canister is closed by means of a metering valve. The metering valve is designed to accurately and consistently dispense a predetermined volume of substance on each actuation of the pMDI. The substance to be dispensed may be one of a wide range of substances. Typically, the substance will include one or more active components (such as medicaments) and a propellant that is volatile at standard pressures and temperatures. 
         [0004]    To prepare a pMDI (or other dispensing apparatus) for use, it may be necessary to prepare or “prime” the metering valve of the pMDI by carrying out one or more actuations of the pMDI (which are not administered to the user) before putting the pMDI to normal use. Such priming actuations are designed to ensure that the metering valve of the pMDI is properly charged with the substance to be dispensed—since a metering chamber of the metering valve may initially be wholly or partly empty immediately after assembly of the pMDI. Thus the priming actuations are carried out to ensure that a full dose is delivered on the first ‘normal’ actuation by the user where administration of the substance is desired. 
         [0005]    It is preferred that the priming actuations are carried out by the user when they first receive the pMDI, for example from a doctor or pharmacy, so that the metering valve is not potentially left for a long time between priming and its first normal use. Thus, there is a need for the instructions for the priming of the pMDI to be clear to the user. It is also preferable for any dose counter, that is present in the pMDI, not to record the priming actuations as dispensed doses. Rather, it is preferred that the dose counter should indicate that the pMDI is ‘full’ or shows the first it its series of numerical or other indicia after the priming actuations are completed. 
         [0006]    EP2514468 describes a dose counter for a pMDI which comprises a tape reel bearing dose indicia that is moved from a first shaft to a second shaft past a viewing window during use of the pMDI. Priming dots are provided at the start of the tape reel which are initially displayed to a user to prompt them to carry out three priming actuations wherein the tape reel then displays the start of the sequence of numerical count indicia. Each portion of the tape reel is only viewed once by the user as it transits past the viewing window. 
         [0007]    However, the use of priming dots at the start of a tape reel as described in EP2514468 is not suitable for use with dose counters of the type having one or more rotatable indicator members, especially where one or more of the rotatable indicator members may need to complete more than one revolution during the life of the dispensing apparatus. 
         [0008]    According to the present disclosure there is provided a dose counter for displaying a count indication of the number or quantity of doses dispensed from or remaining in a container associated, in use, with the dose counter, 
         [0009]    the dose counter comprising:
       an indicator member comprising dose indicia; and   a priming indicator for prompting a user to carry out one or more priming actuations of the container;       
 
         [0012]    wherein the priming indicator is initially arranged to at least partially overly the indicator member to thereby at least partially obscure viewing of the dose indicia of the indicator member until the one or more priming actuations of the container have been completed; 
         [0013]    wherein the priming indicator is movable after the one or more priming actuations have been completed into a disposition where it no longer obscures viewing of the dose indicia of the indicator member. 
         [0014]    Advantageously, by using a priming indicator that at least partially obscures viewing of the dose indicia of the indicator member until the one or more priming actuations of the container have been completed, a simple and clear means of instructing the user to prime the dispensing apparatus is achieved. The use of the priming indicator does not negatively impact the readability of the dose indicia after the priming actuations have been completed. In addition, by making use of a priming indictor that at least partially overlies the indicator member the priming indicator finds use with a wide range of dose counter arrangements, especially those including one or more rotatable indicator members. 
         [0015]    The priming indicator may be movable into the disposition where it no longer obscures viewing of the dose indicia of the indicator member by movement of the indicator member itself. In such a case, a simpler construction of dose counter may be achieved as no separate means need be provided to provide a motive force for moving the priming indicator. 
         [0016]    The priming indicator may be initially coupled to the indicator member to thereby be moved with the indicator member during the one or more priming actuations. Thus, the priming indicator and the indicator member may be arranged to move in-sync with one another during the one or more priming actuations. Advantageously, the mechanism of the dose counter provided to achieve movement of the indicator member (which may be any one of a number of possible mechanisms) may also be used to move the priming indicator—avoiding the need for any separate source of motive force. 
         [0017]    In such a case, the priming indicator is preferably able to be decoupled from the indicator member after the one or more priming actuations have been completed. Thus, during the remainder of the life of the dispensing apparatus movement of the indicator member need not move the priming indicator. 
         [0018]    There are a number of possible means for decoupling the priming indicator. One possibility is that the priming indicator is able to be decoupled from the indicator member by the action of gravity. This allows for a simple arrangement where, for example, the priming indicator drops out of its coupled configuration. 
         [0019]    The indicator member may comprise a rotatable member. In one example the indicator member comprises an annular ring wherein the dose indicia may be arranged on an outer peripheral face of the annular ring. 
         [0020]    The indicator member and the priming indicator may comprise co-operating formations for coupling the priming indicator to the indicator member. 
         [0021]    There are a number of possible configurations of co-operating formations for coupling the priming indicator to the indicator member. One possibility is where the co-operating formations comprise one or more legs provided on the priming indicator and one or more apertures in the indicator member. The one or more apertures may, for example, comprise one or more notches or indentations in an edge of the indicator member. In such a case, coupling may be achieved when the one or more legs of the priming indicator are engaged in the one or more apertures and decoupling may be achieved when the one or more legs are allowed to disengage from the one or more apertures. Preferably, the dispensing apparatus would be provided to the user with the priming indicator initially coupled to the indicator member—in this example, therefore with the one or more legs initially engaged with the one or more apertures. The use of notches or indentations in the edge of the indicator member may have the advantage of allowing easier decoupling of the priming indicator since decoupling can be achieved with a greater degree of choice of the direction of movement of the priming indicator relative to the indicator member. For example, the one or more legs may be moved either perpendicularly or parallel to the plane of the indentation or notch. 
         [0022]    The priming indicator may be movable after the one or more priming actuations have been completed into a disposition where it no longer overlies the indicator member. In this position the priming indicator may, for example, be parked for the remainder of the life of the dispensing apparatus. 
         [0023]    In some examples, the indicator member may form a first indicator member of the dose counter and the dose counter may further comprise a second indicator member; the first and second indicator members acting in combination to display the count indication. The use of two (or more) indicator members in combination may be useful in a number of circumstances. In one example, the two indicator members can be used to display a greater number of dose indicia than would be possible on a single indicator member. In another example, the two indicator members could display different, for example associated, indicia—for example, with the first indicator member displaying a numerical count and the second indicator member displaying a colour indication. 
         [0024]    In such a case, the first indicator member may, for example, be arranged to move on each actuation of the associated container and the second indicator member may be arranged to move after a predetermined number of incremental movements of the first indicator member. Such an arrangement may be used wherein the dose indicia of the first indicator member displays a ‘units’ numeral (or other suitable marking/colour/indicia) of the count indication and wherein the second indicator member comprises dose indicia which display a ‘tens’ numeral (or other suitable marking/colour/indicia) and, optionally additionally a ‘hundreds’ numeral (or other suitable marking/colour/indicia) of the count indication. 
         [0025]    It may be advantageous for the first indicator member to comprise a plurality of sequentially arranged arrays of ‘units’ numerals, each array ranging from ‘9’ to ‘0’. Thus one complete revolution of the first indicator member may be configured to increment the second indicator member a plurality of steps. 
         [0026]    Where the dose counter comprises at least two indicator members, the priming indicator may be initially arranged to at least partially overly the first indicator member and to at least partially overly the second indicator member to thereby at least partially obscure viewing of the dose indicia of both the first and second indicator members. This helps to prevent any of the dose indicia being mistakenly read until the one or more priming actuations have been completed. 
         [0027]    Where the dosage counter comprises first and second indicator members, the priming indicator may be initially coupled to the first indicator member to thereby be carried with the first indicator member and to be moved relative to the second indicator member during the one or more priming actuations. The priming indicator may be arranged to be decoupled from the first indicator member after the one or more priming actuations have been completed. Optionally, the priming indicator may be arranged to become coupled with the second indicator member on decoupling from the first indicator member. Optionally, after coupling of the priming indicator to the second indicator member, the priming indicator may be carried with the second indictor member during subsequent actuations of the associated container. In such a case, it is preferred that the second indicator member is configured to complete less than a complete revolution (in the case of the indicator members being rotatable indicator members) during the lifetime of the dispensing apparatus so as to prevent the priming indicator returning into a position where it again obscures viewing of the dose indicia. 
         [0028]    The first indicator member and the second indicator member may both comprise a rotatable member. The first indicator member and the second indicator member may each comprise an annular ring having dose indicia arranged on an outer peripheral face of the annular ring. The first indicator member, the second indicator member and the priming indicator may comprise co-operating formations for coupling the priming indicator initially to the first indicator member and subsequently to the second indicator member. As described above, the co-operating formations may, by way of example, comprise one or more legs provided on the priming indicator and one or more apertures in the first and second indicator members. The one or more apertures may comprise one or more notches or indentations in an edge of the first and/or second indicator members. 
         [0029]    As in the above example, the priming indicator may be movable after the one or more priming actuations have been completed into a disposition where it no longer overlies the first indicator member. 
         [0030]    According to the present disclosure the priming indicator may be a separate component from the indicator member. For example, the priming indicator may be a relatively small shutter-like component. The priming indicator may be shaped to conform generally to the shape of the first and/or second indicator member. For example, where the indicator member(s) are annular rings the priming indicator may comprise a body that is generally curved to match the curvature of the annular rings. 
         [0031]    The priming indicator may comprise priming indicia suitable for viewing in place of the dose indicia of the indicator member until the one or more priming actuations of the container have been completed. 
         [0032]    The present disclosure also provides a dispensing apparatus comprising a dose counter as described above. 
         [0033]    The dispensing apparatus may further comprise a container containing a quantity of substance to be dispensed. 
         [0034]    The dispensing apparatus may comprise a viewing window for viewing the count indication of the dose counter, wherein the priming indicator is initially arranged at least partially inbetween the indicator member and the viewing window to thereby at least partially obscure viewing of the dose indicia of the indicator member until the one or more priming actuations of the container have been completed; 
         [0035]    wherein the priming indicator is movable after the one or more priming actuations have been completed into a disposition where it is no longer inbetween the viewing window and the indicator member. 
         [0036]    In one example, the dispensing apparatus is a pressurised metered dose inhaler (pMDI). Another example of a use of a suitable dispensing apparatus is a pump, for example a nasal, oral or sub-lingual pump device. 
         [0037]    The dose indicia of the indicator member(s) may be of any suitable type for conveying the necessary information to the user. Examples include numbers, letter, colours and pictograms. Such indicia may be used in combination if desired. For example, number indicia may be used as the main indicia (for example counting down from ‘200’ to ‘000’ doses remaining) combined with a change of colour indicia as the empty point approaches (for example the ‘tens’ or ‘hundreds’ indicator member may be provided with a red zone at or near the empty point). 
         [0038]    The priming indicia of the priming indicator may be of any suitable type for conveying the necessary information to the user. Examples include dots, numbers, colours or pictograms. Preferably a different style of indicia is chosen for the priming indicia compared to the dose indicia. 
         [0039]    The dispensing apparatus may be a pharmaceutical dispensing apparatus, such as, for example, a pulmonary, nasal, or sub-lingual delivery device. A preferred use of the dispensing apparatus is as a pressurised metered dose inhaler device for delivering a pharmaceutical in an aerosol form. Another use of the dispensing apparatus is as a pump 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 pharmaceuticals, drugs, biological and medicinal products. Examples include antiallergics, analgesics, bronchodilators, antihistamines, therapeutic proteins and peptides, antitussives, anginal preparations, antibiotics, anti-inflammatory preparations, hormones, or sulfonamides, such as, for example, a vasoconstrictive amine, an enzyme, an alkaloid, or a steroid, including combinations of two or more thereof. In particular, examples include isoproterenol [alpha-(isopropylaminomethyl) protocatechuyl alcohol], phenylephrine, phenylpropanolamine, glucagon, adrenochrome, trypsin, epinephrine, ephedrine, narcotine, codeine, atropine, heparin, morphine, dihydromorphinone, ergotamine, scopolamine, methapyrilene, cyanocobalamin, terbutaline, rimiterol, salbutamol, ipratropium bromide and salbutamol, flunisolide, colchicine, pirbuterol, beclomethasone, orciprenaline, fentanyl, and diamorphine, streptomycin, penicillin, procaine penicillin, tetracycline, chlorotetracycline and hydroxytetracycline, adrenocorticotropic hormone and adrenocortical hormones, such as cortisone, hydrocortisone, hydrocortisone acetate and prednisolone, insulin, cromolyn sodium, and mometasone, including combinations of two or more thereof. 
         [0040]    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, dihydrochloride, edetate, edisylate, estolate, esylate, fumarate, fluceptate, gluconate, glutamate, glycollylarsanilate, hexylresorcinate, hydrobromide, hydrochloride, hydroxynaphthoate, iodide, isethionate, lactate, lactobionate, malate, maleate, mandelate, mesylate, methylbromide, methylnitrate, methylsulphate, mucate, napsylate, nitrate, pamoate, (embonate), pantothenate, phosphate, diphosphate, polygalacturonate, salicylate, stearate, subacetate, succinate, sulphate, tannate, tartrate, and triethiodide, including combinations of two or more thereof. Cationic salts may also be used, for example the alkali metals, e.g. Na and K, and ammonium salts and salts of amines known in the art to be pharmaceutically acceptable, for example glycine, ethylene diamine, choline, diethanolamine, triethanolamine, octadecylamine, diethylamine, triethylamine, 1-amino-2-propanol-amino-2-(hydroxymethyl)propane-1,3-diol, and 1-(3,4-dihydroxyphenyl)-2 isopropylaminoethanol. 
         [0041]    The pharmaceutical will typically be one which is suitable for inhalation 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. 
         [0042]    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, salmeterol xinafoate, fluticasone propionate, beclomethasone dipropionate, and terbutaline 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 flutiform, and may optionally be provided together with a suitable carrier, for example a liquid carrier. One or more surfactants may be included if desired. 
         [0043]    Rigid components of the dispensing apparatus may be formed from, for example, from polyester, nylon, acetal or similar. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0044]    In order that the disclosure may be fully disclosed, an embodiment will now be described, by way of example, with reference to the accompanying drawings, in which:— 
           [0045]      FIG. 1  is a perspective view of a dispensing apparatus as described in EP 1 859 829; 
           [0046]      FIG. 2  is a cross-sectional view of the dispensing apparatus of  FIG. 1 ; 
           [0047]      FIG. 3  is a perspective view of various internal features of the dispensing apparatus of  FIG. 1 ; 
           [0048]      FIG. 4  is a perspective view of first and second number rings and a cog forming part of the dispensing apparatus of  FIG. 1 ; 
           [0049]      FIG. 5  is a perspective view of the cog forming part of the dispensing apparatus of  FIG. 1 ; 
           [0050]      FIG. 6  is a perspective view of a sleeve forming part of the dispensing apparatus of  FIG. 1 ; 
           [0051]      FIG. 7  is a perspective view of a first number ring having two different diameter portions, forming part of the dispensing apparatus of  FIG. 1 ; 
           [0052]      FIG. 8  is a perspective view of the dispensing apparatus of  FIG. 1  with the mouthpiece detached and some parts shown in cross-section; 
           [0053]      FIG. 9  is a schematic view of part of the apparatus of  FIG. 1  with some parts omitted for clarity; 
           [0054]      FIG. 10  is a perspective view of a priming indicator according to the present disclosure; 
           [0055]      FIG. 11  is a perspective view from a first angle of first and second number rings and the priming indicator of  FIG. 10  in an initial position before priming; 
           [0056]      FIG. 12  is a perspective view of the first and second number rings and the priming indicator of  FIG. 11  in a second position immediately after priming; 
           [0057]      FIG. 13  is a perspective view showing the arrangement of  FIG. 11  (before priming) from a reverse angle; 
           [0058]      FIG. 14  is a perspective view from the reverse angle showing the arrangement of  FIG. 11  after a first priming actuation; 
           [0059]      FIG. 15  is a perspective view from the reverse angle showing the arrangement of  FIG. 11  after two priming actuations; 
           [0060]      FIG. 16  is a perspective view showing the arrangement of  FIG. 12  (after three priming actuations) from the reverse angle; and 
           [0061]      FIG. 17  shows a front view of four configurations of a dispensing apparatus according to the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0062]    For the purposes of illustrating the dose counter and dispensing apparatus of the present disclosure they will be described with reference to the field of application of pressurised metered dose inhalers (pMDIs), an example of which is described in detail in the applicant&#39;s European patent publication EP 1 859 829. The contents of EP 1 859 829 are hereby incorporated by reference. However, it should be understood that the present disclosure is not limited to a dispensing apparatus of the specific design described below and in EP 1 859 829 but finds application with other dispensing apparatus, for example pump devices. 
         [0063]      FIGS. 1 to 9  show a pMDI as described in EP 1 859 829 and are provided and described herein for the better understanding of the example of the present disclosure that will be described in detail further below. 
         [0064]    The dispensing apparatus, in the form of a pMDI, shown in  FIG. 1 , is indicated generally at  1 , and has an upper body  3 , a lower body  5  and a detachable mouthpiece  20  shown in  FIG. 8 . A dust cap may be used to cover the mouthpiece  20  when the apparatus is not in use. As shown in  FIG. 2 , the pMDI  1  also incorporates a dose counter having first and second number rings  11 ,  13 , a cog  12  and a sleeve  100 . The pMDI  1  holds a pressurised dispensing container  10 . 
         [0065]    The lower body  5  is open at its upper end. The lower body  5  houses the cog  12  and the first and second number rings  11 ,  13 . As shown in more detail in  FIG. 3 , the number rings  11 ,  13  rest upon internal projections  111  of the main body  5 . Such internal projections  111  provide up facing surfaces upon which the second number ring  13  may rest and rotate, during use. The first number ring  11  rests and rotates, during use, on top of the second number ring  13 . The cog  12  is rotatably mounted within the main body  5  on a cylindrical portion  112  and interacts with both first and second number rings  11 ,  13 . As can be seen, the axis of rotation of the cog  12  is offset from the axes of the numbered rings  11 ,  13  but parallel thereto so that the cog  12  can interact with both number rings  11 ,  13  which are housed in the substantially cylindrical part of the lower body  5  without impeding axial movement of the container  10 . The lower body  5  is provided at a lower end thereof with an axial protrusion  121  integral with the lower body  5 . The axial protrusion  121  comprises a hollow elongate portion into which the valve stem  22  of the container  10  can be received as a relatively tight interference fit. The hollow portion is provided with a narrowed constriction against which the valve stem  22  can abut when the dispensing apparatus is actuated. The hollow portion forms a conduit  124  that is in fluid communication with the outlet of the valve stem of the pressurised dispensing container  10  when the container is inserted into the apparatus. The axial protrusion  121  protrudes from the lower end of the lower body  5  as shown in  FIG. 2 . The axial protrusion  121  provides protection for the valve stem when the mouthpiece  20  has been removed and also directs dispensed product into the removable mouthpiece  20 . 
         [0066]    The lower body  5  and upper body  3  are connectable together using co-operating formations which are push-fit together as shown in  FIG. 2 . 
         [0067]    The detachable mouthpiece  20  is attached to the main body  5  by means of a bayonet fitting. As shown in  FIGS. 2 and 8  the mouthpiece  20  is provided with an upstanding rim  120  in which are formed two opposed recesses  123  of roughly an L-shape configuration. The main body  5  comprises a circumferential recess  195  which receives the rim  120  when the two pieces are coupled together. At opposed points of the circumferential recess  195  the lower body  5  is provided with retaining lugs  125  which pass along the recesses  123  of the mouthpiece. Thus the mouthpiece may be coupled to the lower body  5  by locating the lugs  125  relative to the upper end of the recesses and then twisting the lower body  5  relative to the mouthpiece  20  whilst applying a compressive axial force to the two components. This results in the lugs  125  riding along the recesses resulting in the two components being firmly connected. The mouthpiece  20  is also provided with a spray block  14  for receipt of the axial protrusion  121 . The spray block  14  comprises a conduit having an upper end which receives the axial protrusion  121  and a lower end which comprises a spray outlet directed towards the outlet of the mouthpiece  20 . The spray outlet may be provided with a suitably dimensioned orifice or spray pattern block as known in the art to produce an atomised spray of product on dispensation. 
         [0068]    The first number ring  11  is provided with an upper row of angled abutment surfaces  41   a  located on a larger diameter portion of that number ring as shown in  FIG. 7 . A lower set of angled abutment surfaces are formed on a smaller diameter portion of the ring in the form of a series of inwardly directed projections  310  having a triangular cross-section when viewed from above. The projections  310  are arranged around the circumference of the lower portion of the ring  11  so as to form a series of interspersed peaks and troughs. Each projection  310  comprises two faces  311 ,  312  on either side of the peak. Preferably, the faces  311 ,  312  are arranged symmetrically about the peak. The faces  311  and  312  form angled abutment surfaces which engage the outward projection  304  of the tension arm  300  in use as will be described below. 
         [0069]    The first number ring  11  comprises at least one notch  40  positioned on the outer edge thereof. The first number ring  11  is also provided with a set of numbering (not shown in  FIGS. 1 to 9 ) from 0 to 9 for each notch  40 , so that after each ninth actuation of the pMDI  1 , a notch  40  is in position to interact with the cog  12 . In one embodiment, the first number ring  11  will have three notches  40  and, so, will have three sets of numbering from 0 to 9 around its circumference. 
         [0070]    The second number ring  13  comprises a set of teeth  500  and may be provided with an extended portion  150 , as shown in  FIG. 4 , which is positioned to enable covering of the markings on the first number ring  11  when the pressurised dispensing container  10  located in the pMDI is empty. Advantageously, the extended portion  150  provides a clear indication to a user that the pMDI has provided its full-quota of dispensations. 
         [0071]    The cog  12 , as shown in  FIG. 5  in particular, is provided with one or more teeth separated by a non-toothed, cylindrical, spacer  160 . A first end  161  of the cog  12  includes four teeth  162  of reduced height and four teeth  164  of full height which in use interact with the first number ring  11 . The full height teeth  164  extend from the spacer  160  to the distal face of the first end  161  of the cog  12 . The teeth  50  at a second end of the cog  12  are all full height and these teeth in use interact with the second number ring  13 . The four teeth  162  having reduced height are, typically, half the height of the full height teeth  164 . Most preferably, the reduced height teeth  162  and full height teeth  164  are arranged alternately around the circumference of the cog  12 . The cog  12  is provided with upper and lower axial projections  190  which allow the cog  12  to be rotationally mounted in recesses formed in the lower body  5  as shown in  FIG. 3 . 
         [0072]    As shown in  FIGS. 2 and 6 , the sleeve  100  comprises an open-ended cylinder  170  having an upper end  171  which can receive the container  10  to be located in the dispensing apparatus  1  and a lower end  172  which has a reduced diameter opening  173  through which the valve stem  22  of the pressurised dispensing container  10 , located within the sleeve  100  may protrude from but through which the body of the container  10  cannot pass. The sleeve  100  is provided with two sets of formations on its exterior surface. The sets of formations are arranged diametrically opposite one another (only one set of formations is shown in  FIG. 6 ). Each set of formations comprises first, second and third formations. The first formation is provided at the lower end  172  in the form of notches  114 . The second formation is provided above the notches  114  in the form of a tension arm  300 . The tension arm  300  comprises a cantilevered portion  301  which is fixed to the sleeve  100  at a hinge point  302 . Preferably, the tension arm  300  is provided in a single moulding as part of the sleeve  100  in which case the hinge point  302  marks the junction between the body of the sleeve  100  and the start of the cantilevered portion  301  of the tension arm  300 . A distal end  303  of the tension arm  300  is provided with an outwardly directed projection  304 . It can be seen from  FIG. 6  that the cantilevered tension arm  300  is able to accommodate flexure in a direction perpendicular to flexure of the cantilevered projection  178 . That is, the outwardly directed projections  304  of the tension arm  300  can flex substantially radially inwards when pressure is applied to the projections in a radially inward direction. It will be appreciated that the shape of the container  10  must accommodate inward flexure of the tension arms  300 . It is therefore preferable that the position of the tension arms  300  be located to coincide with a neck of the container  10  where it narrows to meet a ferrule of the metering valve, thereby forming an undercut. Alternatively, the walls of the container  10  may have formed in them depressions to accommodate inward flexure of the tensions arms  300 . The third formation is provided at the upper end  171  in the form of a cantilevered projection  178 . The cantilevered projection  178  comprises an elongated portion  180  having an angled abutment surface  179  on its lower, distal end. The elongated portion  180  of the cantilevered projection  178  is axially aligned with the projection  175 . The elongated portion  180  is joined to the cylindrical body of the sleeve  100  at a hinge point  181 . A void space  182  is formed around the elongated portion  180  to accommodate movement of the cantilevered projection  179  in use as will be described below. 
         [0073]    The lower body  5  is provided with a clear portion  30 , or one or more apertures  30 , forming a viewing window through which portions provided with markings of the first and second number rings  11 ,  13  are visible. The upper body  3  is transparent to allow a user to easily see the type of container  10  located in the apparatus  1 . 
         [0074]    In use, the internal components of the dose counter, such as the cog  5 , the sleeve  100  and the number rings  11 ,  13  can be loaded into position within the pMDI  1  by separating the upper body  3  from the lower body  5 . The cog, number rings and sleeve  100  can be inserted into the opening of the lower body  5 . The internal projections  110  of the lower body  5  are received slidingly in the notches  114  of the sleeve  100  with the effect that the sleeve  100  is fixed rotationally relative to the lower body  5 . The sleeve  100  is arranged to pass through the central holes/apertures of the number rings  11 ,  13 . The upper body  3  is then attached to the lower body  5 . 
         [0075]    The pressurised dispensing container  10  can now be passed through the hole in the upper body  3  to be received in the sleeve  100 . The valve stem  22  of the pressurised dispensing container  10  is received in the opening of the conduit  124  of the axial protrusion  121  as a relatively tight interference push-fit. When loaded, the first and second number rings  11 ,  13  are located around the container  10  as shown in  FIG. 3 . 
         [0076]    In the inserted position the upper end of the container  10  protrudes upwardly through the hole in the upper body  3  as shown in  FIG. 1 . Preferably, the container  10  only protrudes slightly above the level of the upper body  3 . In the illustrated embodiment scallops  17  are provided in the upper edge of the upper body  3  and the container  10  protrudes above the level of the scallops but does not protrude above the highest part of the upper edge. The depth of the scallops  17  allows a user to depress the container  10  sufficiently to actuate the container&#39;s valve but reduces the area of the container  10  that can be gripped by the fingers of anyone attempting to remove the container  10  from the apparatus  1 . Thus the amount of pulling force that can be applied to the container  10  is not enough to overcome the friction produced by the interference fit between the valve stem  22  and the conduit  124 . Also, the fact that the container  10  does not protrude above the highest part of the upper edge helps to prevent accidental actuation of the apparatus when carried in the pocket. 
         [0077]    The pMDI  1  is actuated by depression of the pressurised dispensing container  10  which protrudes above the scallops  17  of the upper body  3 . Depression of the container  10  causes the container  10  and sleeve  100  to move axially within the main body  5  to actuate the container  10 . Actuation causes an amount of product to be dispensed from the container  10  by an opposite reaction force from the constriction in the axial protrusion  121  acting on the valve stem  22 , which is inwardly retracted relative to the remainder of the metering valve such that an amount of product is dispensed from the valve stem  22  through the conduit  124  and the valve stem receiving block  14 , from where it is dispensed as an aerosol through the mouthpiece  20  and inhaled by a user inhaling on the mouthpiece  20 . Release of the container  10  causes the container to return to its starting position, owing to the internal spring bias of the metering valve, ready for subsequent dispensing. 
         [0078]    Each actuation of the pMDI  1  causes the first number ring  11  to rotate a partial increment during the downstroke of the pressurised dispensing container  10  owing to engagement of the angled abutment surface  179  of the cantilevered projection  178  with the angled abutment surfaces  41   a  the first number ring  11 . This partial rotation of the first number ring  11  causes each outwardly directed projection  304  of each tension arm  300  to ride up an angled face  311  of respective protrusions  310 . This movement is accommodated by the tension arms  310  as they flex radially inwards. The relative location of the angled abutment surfaces  41   a  and the projections  310  is such that when the downstroke of the sleeve  100  is completed the outwardly directed projections  304  of the tension arms  300  have ridden up the angled abutment surfaces  311  and over the peak of the projections  310  such that the outwardly directed projections  304  lie in contact with the angled abutment surfaces  312  of the projections  310 . Thus, when the pressurised dispensing container  10  is released, and the sleeve  100  consequently moves back on its up stroke, the completion of the incremental rotation of the first number ring  11  is achieved by the biasing force of the outwardly directed projections  304  of the tension arms  300  on the angled abutment surfaces  312  as the tension arms  300  try to return to their unstressed position. This biasing force completes the rotation of the first number ring  11  such that the outwardly directed projections  304  of the tension arms  300  lie in the neighbouring trough between the projections  310  after one actuation. Consequently, the cantilevered projection  178  and the tension arm  300  (or the pairs of these features where present) act as first and second indexing members which together act to index the first number ring  11 . 
         [0079]    The first number ring  11  acts as the ‘units’ ring of the dose counter as it is moved on each actuation of the pMDI  1 . The dose indicia on the first number ring  11  may comprise a plurality of sequentially arranged arrays of ‘units’ numerals, each array ranging from ‘9’ to ‘0’. The first number ring  11  is intended to rotate fully a plurality of times during the life of the pMDI  1 . 
         [0080]    Every ten actuations of the pMDI  1  causes one of the notches  40  to pass the cog  12 , the effect of this being that one of the full height teeth  164  of the upper row of teeth is caught in the notch  40  as it rotates, this rotation causing a corresponding rotation of the cog  12  in an opposite sense. As a consequence, the second number ring  13  is caused to rotate in the same sense as the first number ring  11  by interaction of the teeth  50  on the bottom of the cog  12  and the teeth  500  of the second number ring  13 . 
         [0081]    The second number ring  13  acts as the ‘tens’ or ‘tens and hundreds’ ring of the dose counter as it is moved after every ten actuations of the pMDI  1 . The dose indicia on the second number ring  13  may comprise numerals donating the ‘tens’ and ‘hundreds’ numerals of the dose count. For example the numbering may range from to ‘20, 19, 18 . . . ’ to ‘ . . . 3, 2, 1, zero/blank’ to enable the dose counter to display counts ranging from ‘200’ to zero. The second number ring  13  is intended only to rotate up to one revolution during the life of the pMDI  1 . 
         [0082]      FIGS. 10 to 17  illustrate an example of a dispensing apparatus according to the present disclosure, again in the exemplar form of a pMDI  1 , which incorporates a dose counter, also according to the present disclosure. In describing the pMDI  1  and dose counter only those features which differ from the arrangement described above and shown in  FIGS. 1 to 9  will be described in detail. In other respects, the features are as described above. In addition, the following description of the pMDI  1  and dose counter are provided by way of example only and it should be understood that the dose counter of the present disclosure is not limited to use with the pMDI  1  shown in  FIGS. 1 to 9  but is only described incorporated in such a dispensing apparatus for the better understanding of the disclosure. 
         [0083]    In a first difference, the dose counter of the pMDI  1  is provided with an additional component in the form of a priming indicator  90  which is shown in  FIG. 10 . The priming indicator  90  comprises a curved body  91  which is relatively elongate having a length which is significantly greater than its width. In addition, the thickness of the curved body  91  is relatively small. 
         [0084]    The priming indicator  90  is provided with a pair of legs. A first leg  93  is provided at one end of the curved body  91  (the right-hand end as viewed in  FIG. 10 ) and a second leg  94  is arranged approximately midway along the length of the curved body  91 . Each of the first leg  93  and the second leg  94  project from a rear face of the priming indicator  90  and perpendicularly thereto. The first leg  93  is wider than the second leg  94 , (the ‘width’ of the legs being measured in the ‘length’ direction of the curved body  91 ). 
         [0085]    The front face of the curved body  91  is provided with one or more priming indicia  95  spaced along the length of the curved body  91 . In the illustrated example, three priming indicia  95  are provided in the form of three, two and one dots. 
         [0086]    Optionally, and as shown in the example of  FIG. 10 , the end of the curved body  91  distal the first leg  93  (the left-hand end as viewed in  FIG. 10 ) has a reduced width portion  92 . A dose indicia  96  (or part of a dose indicia) is provided on the front face of the reduced width portion  92 . In the example illustrated, the dose indicia  96  is the numeral ‘20’ which in use will form part of the number ‘200’. 
         [0087]    In a second difference, the first number ring  11  and the second number ring  13  are provided with notches in their mutually-facing annular edges. For example, as shown in  FIG. 11 , the second number ring  13  comprises a first notch  81  and a second notch  80 . Both the first notch  81  and the second notch  80  have a rectangular cross-section and are both formed in the upper annular edge of the second number ring  13  so that the open mouths of the first and second notches  81 ,  80  face upwards when viewed in the orientation shown in  FIG. 11 . 
         [0088]    First number ring  11  also comprises a pair of notches which are obscured in  FIG. 11 . The notches can be seen in  FIGS. 13 to 16  and comprise a first notch  88  and a second notch  89 . As with the notches of the second number ring  13 , the first notch  88  and the second notch  89  are both rectangular in shape but in this instance are provided on the lower annular edge of the first number ring  11  so as to face downwards when viewed in the orientation of  FIGS. 12 to 16 . 
         [0089]    The first and second notches  81 ,  80  of the second number ring  13  are spaced apart from one another by a set distance. The first and second notches,  88 ,  89  of the first number ring  11  are also set apart from each other by the same set distance. 
         [0090]    The second notch  80  of the second number ring  13  is narrower than the first notch  81  of the second number ring  13 . Similarly, the second notch  89  of the first number ring  11  is narrower than the first notch  88  of the first number ring  11 . The legs  93 ,  94  and the notches  80 ,  81 ,  88 ,  89  are configured to form co-operating formations. Importantly, the width of the second notch  80  of the second number ring  13  and the second notch  89  of the first number ring  11  are sized to be able to receive the thinner second leg  94  of the priming indicator  90  but to be too narrow to receive the wider first leg  93  of the priming indicator  90 . The first notch  81  of the second number ring  13  and the first notch  88  of the first number ring  11  are configured to be wide enough to receive the first leg  93  of the priming indicator  90 . 
         [0091]    As noted above, the first and second number rings  11 ,  13  are provided with dose indicia. In  FIGS. 11 to 17 , the dose indicia  86  of the first number ring  11  comprise three sequential arrays of numerals ‘9’ to ‘0’. The dose indicia  87  of the second number ring  13  comprise an array of numerals ‘19’ to ‘_l’ followed by a space bearing no numeral. In addition, as shown in  FIG. 13 , the second number ring  13  is provided with a red zone marking  87   a  which extends from the ‘_2’ dose indicia  87  to the space bearing no numeral. The red zone marking  87   a  provides an additional indication to the user that the pMDI  1  is nearly empty or empty (in the illustrated example the red zone marking  87   a  will be visible for the last  20  doses of the life of the pMDI  1 ). 
         [0092]      FIG. 11  illustrates an initial position of the dose counter before priming of the pMDI  1  has taken place. For clarity reasons  FIG. 11  has omitted other features of the dose counter and pMDI other than the first number ring  11 , second number ring  13  and the priming indicator  90 . For clarity, the viewing location of the dose counter (the portion of the dose counter visible to the user from outside the pMDI) is illustrated by the dashed rectangle  85 . For example, rectangle  85  illustrates the location of the viewing window  30  formed in the lower body  5  of the pMDI  1  as shown in  FIGS. 1 and 17 . 
         [0093]    In the initial position of  FIG. 11 , the priming indicator  90  is coupled to the first number ring  11  by virtue of the engagement of the first leg  93  in the first notch  88  and the second leg  94  in the second notch  89 . As can be seen from  FIGS. 13 and 14 , the size and shape of the first and second legs  93 ,  94  are configured to fit in the first notch  88  and second notch  89  respectively. The priming indicator  90  is thus held up in the position shown in  FIG. 11  wherein the curved body  91  of the priming indicator  90  partly overlies the outer face of the first number ring  11  and partly overlies the outer face of the second number ring  13 . The priming indicator  90  is prevented from dropping downwards in the orientation as viewed in  FIG. 11  by virtue of the fact that the first leg  93  and second leg  94  rest on the upper annular edge of the second number ring  13 . The priming indicator  90  is prevented from de-coupling from the number rings  11 ,  13  in the radially outward direction by virtue of the presence of the surrounding housing which is not illustrated in  FIGS. 11 to 16 . 
         [0094]    In the initial position of  FIG. 11 , the priming indicia  95  showing three dots is located at the viewing location  85  as illustrated in the first illustration of  FIG. 17 . This is intended to inform the user that three priming actuations are still required before the pMDI  1  is ready for normal use. In this position the priming indicator  90  obscures viewing of the dosage indicia  86  of the first number ring  11 . Preferably, and as shown in  FIG. 11 , the second number ring  13  has a gap in its array of dosage indicia  87  where a ‘20’ indicia would otherwise be positioned. 
         [0095]    To prime the pMDI  1 , the user carries out a first priming actuation by operating the pMDI  1  in the manner described above and in the referenced application EP 1 859 829. As will be appreciated, this priming actuation causes the first counter ring  11  to rotate by one incremental step. This moves the first counter ring  11  from the position shown in  FIGS. 11 and 13  to the position shown in  FIG. 14 . 
         [0096]    As shown in  FIG. 14 , after completion of the first priming actuation, the first number ring  11  has rotated to the point where the first notch  88  containing the first leg  93  of the priming indicator  90  has just passed the location of the second notch  80  of the second number ring  13 . Due to the fact that the first leg  93  is wider than the second notch  80 , the first leg  93  does not drop into the second notch  80  but rides over the second notch  80  and the priming indicator  90  remains coupled to the first number ring  11 . At this point the priming indicia  95  showing two dots is now aligned with the viewing location  85  as illustrated in the second illustration of  FIG. 17 . 
         [0097]    Next, a second priming actuation is carried out which moves the dose counter into the configuration shown in  FIG. 15 . As can be seen, the first leg  93  and second leg  94  of the priming indicator  90  have continued to ride along the upper annular edge of the second number ring  13 . At this point, the priming indicia  95  showing a single dot is aligned with the viewing location  85  as illustrated in the third illustration of  FIG. 17 . 
         [0098]    Next, a third and final priming actuation is carried out which moves the dose counter into the configuration shown in  FIGS. 12 and 16 . As can be seen best in  FIG. 16 , the first number ring  11  has now been rotated to the point where the notches  81 ,  80  of the second number ring  13  have become aligned with the notches  88 ,  89  of the first number ring  11 . This allows the first leg  93  and the second leg  94  of the priming indicator  90  to drop down into the first notch  81  and the second notch  80  respectively of the second number ring  13 . Thus, the priming indicator  90  drops under gravity to de-couple from the first number ring  11  and to become coupled to the second number ring  13 . The consequence of this for the user is shown in  FIG. 12  and in the fourth illustration of  FIG. 17  where it can be seen that the first number ring  11  is no longer obscured by the priming indicator  90  as the priming indicator  90  has moved to a point where it no longer overlies the first number ring  11 . In the illustrated example, the priming indicator  90  still overlies the array of dose indicia  87  of the second number ring  13  within the viewing location  85  but is aligned such that the dose indicia  96  in the form of the numerals ‘20’ on the priming indicator  90  is displayed instead. This together with the ‘0’ numeral of the dose indicia  86  of the first number ring  11  displays the correct, first, dose indicia ‘200’ of the dose counter. This conveys the information to the user that the pMDI  1  has been primed and is now ready for normal use. Of course, it will be appreciated that the priming indicator  90  could be adapted by removing the reduced width portion  92  such that after the third priming actuation no part of the priming indicator  90  is visible at the viewing location  85 . 
         [0099]    It will be noted that during the subsequent normal actuations of the pMDI  1 , the first number ring  11  will continue to rotate as before and after every 10 actuations will incrementally rotate the second number ring  13 . The priming indicator  90  will remain coupled to the second number ring  13  and move in sync with it for the rest of the life of the pMDI  1 . However, the configuration of the dose counter is that the second number ring  13  does not complete a single full revolution during the normal life of the pMDI  1 . Thus, the priming indicator  90  never moves back into sight at the viewing location  85 . Consequently, once the priming indicator  90  has carried out its function at the start of life of the pMDI  1  to prompt a user it to carry out the required number of priming actuations it no longer stays visible and therefore does not inhibit in any way the correct reading of the dose counter during normal use.