Abstract:
Dose counter assemblies are provided herein which allow for the counting of used doses of a medical inhaler. In one aspect, one dose counter ring is utilized. This provides for dose counting but with inherent limitations in the number of doses which may be counted. In a second, and preferred, aspect of the subject invention, two cooperating does counter rings are utilized which allow for adjacent digits to be displayed, thereby allowing an increased number of doses to be counted. Advantageously, with the subject invention, due to mechanical interactions, reliable dose counting can be achieved with the subject invention.

Description:
FIELD OF THE INVENTION 
       [0001]    The subject invention relates to dose counters and, more particularly, to dose counters for use with medical inhalers, such as dry powder inhalers. 
       BACKGROUND OF THE INVENTION 
       [0002]    Medical inhalers, such as dry powder inhalers (DPI&#39;s) and metered dose inhalers (MDI&#39;s) are well known in the art. With such inhalers being closed containers, the amount of remaining doses of medication may be difficult to ascertain. Dose counters have been developed in the prior art useable with such inhalers to count used doses and provide an indication of remaining available doses. For example, U.S. Pat. No. 6,240,918 discloses a dose counter assembly useable with a dry powder inhaler. 
       SUMMARY OF THE INVENTION 
       [0003]    Dose counter assemblies are provided herein which allow for the counting of used doses of a medical inhaler. In one aspect, one dose counter ring is utilized. This provides for dose counting but with inherent limitations in the number of doses which may be counted. In a second, and preferred, aspect of the subject invention, two cooperating dose counter rings are utilized which allow for adjacent digits to be displayed, thereby allowing an increased number of doses to be counted. Advantageously, with the subject invention, due to mechanical interactions, reliable dose counting can be achieved with the subject invention. 
         [0004]    These and other features of the invention will be better understood through a study of the following detailed description and accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIGS. 1-3  show an inhaler useable with a dose counter assembly of the subject invention; and, 
           [0006]      FIGS. 4-18  show a dose counter assembly, and components thereof, in accordance with the subject invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0007]    With reference to the Figures, particularly  FIGS. 3-18 , a dose counter assembly  10  is shown useable for counting used doses of a medical inhaler. As described below, the assembly  10  relies on rotational movement imparted thereto and, as such, is particularly well-suited f or use with dry powder inhalers. The assembly  10  can be used with the dry powder inhaler disclosed in U.S. Pat. No. 6,240,918, which is incorporated by reference herein in its entirety. As will be appreciated by those skilled in the art, metered dose inhalers utilize axial movement, typically without rotation, for use. The assembly  10  could be used with a metered dose inhaler where a portion of the axial movement is translated into rotational movement for operation of the assembly  10 , as described below. 
         [0008]    The assembly  10  may be configured in various ways to permit various number of doses to be counted. The number of doses to be counted should correlate to the capacity of the reservoir of the corresponding inhaler. In this manner, the assembly  10  may count down the proper number of doses available in the associated reservoir. The assembly  10  can be configured with a single dose counter ring, as described below, which permits counting the doses incrementally about its entire circumference. A single dose counter ring, however, is limited in the number of doses. It is preferred that the assembly  10  include two dose counter rings, as described below, which permit for two and three digit display, i.e., having at least ones and tens columns and possibly having a hundreds column. 
         [0009]    In the preferred embodiment, the assembly  10  generally includes a housing  12 , a base  14 , a first dose counter ring  16 , a second dose counter ring  18  and an indexer  20 . 
         [0010]    The housing  12  is generally tubular and includes a window  22  defined therein. 
         [0011]    As best shown in  FIG. 10 , the base  14  includes a disc-shaped body  24  from which extends upwardly post  26 . First and second rings of teeth  28 ,  30  are concentrically disposed about the post  26 . Preferably, the first and second teeth  28 ,  30  are saw-tooth shaped. The base  14  may be fixed to the housing  12  using any known technique so as to be fixed immovably thereto. Alternatively, the base  14  may be formed integrally with the housing  12 . 
         [0012]    With reference to  FIGS. 17 and 18 , the first dose counter ring  16  includes a body  32  having opposing first and second faces  34 ,  36 . A central aperture  38  is formed to extend through the first and second faces  34 ,  36  with the central aperture  38  being configured to allow passage therethrough of the post  26 . As configured, the first dose counter ring  16  may be mounted onto the post  26  for rotation thereabout. 
         [0013]    The first face  34  of the first dose counter ring  16  includes at least one ratchet tooth  40  extending therefrom formed to be nestingly received between an adjacent pair of the first teeth  28  ( FIG. 8 ). It is preferred that a continuous ring of ratchet teeth  40  be provided formed to be simultaneously nestingly received in the first teeth  28 . It is also preferred that the ratchet teeth  40  be saw-tooth shaped. At least one recess  42  is defined through the second face  36  and, preferably, extends completely through the first face  34  so as to form a through hole. A plurality of the recesses  42  may be provided, as shown in the Figures, including being disposed in a ring pattern about the central aperture  38 . 
         [0014]    Side wall  44  depends downwardly from the body  32  so as to at least partially bound the first face  34 . Preferably, the side wall  44  is located at the outer periphery of the body  32 . External surface  46  of the side wall  44  includes indicia  48  useable for counting doses. 
         [0015]    With reference to  FIGS. 15 and 16 , the second dose counter ring  18  includes a body  50  having opposing first and second faces  52 ,  54 . A central aperture  56  extends between and through the first and second faces  52 ,  54  sized to permit mounting of the second dose counter ring  18  onto the post  26  for rotation thereabout. A collar  58  may bound all or a portion of the central aperture  56  on one or both of the first and second faces  52 ,  54  sized to mount onto the post  26 . The collar  58  provides additional stability to the second dose counter ring  18  about the post  26 . 
         [0016]    At least one ratchet tooth  60  is formed on the first face  52 . It is preferred that a plurality of ratchet teeth  60  be provided in a circular pattern so as to be simultaneously nestingly received among the second teeth  30  of the base  14  ( FIG. 8 ). Preferably, the ratchet teeth  60  are saw-tooth shaped. As assembled, the second dose counter ring  18  lies atop the first dose counter ring  16  which, in turn, lies atop the body  24  of the base  14 . To permit the ratchet teeth  60  to engage the second teeth  30  of the base  14 , the central aperture  38  of the first dose counter ring  16  is provided with sufficient diameter to allow such interengagement. Preferably, the first face  52  of the second dose counter ring  18  is provided with a raised portion  62  on which the one or more ratchet teeth  60  are defined. The raised portion  62  provides sufficient extension for the one or more ratchet teeth  60  to engage the second teeth  30 . Alternatively, the second teeth  30  may be raised on the body  24  so as to extend through the central aperture  38  into engagement with the one or more ratchet teeth  60 . As will be appreciated by those skilled in the art, some combination of these two configurations is also permitted whereby both the second teeth  30  and the one or more ratchet teeth  60  are raised. 
         [0017]    The second dose counter ring  18  includes a plurality of tertiary teeth  64  defined on or adjacent to the second face  54 . Preferably, the tertiary teeth  64  are saw-tooth shaped. Also, preferably, the tertiary teeth  64  are provided in a continuous ring pattern. A side wall  66  may be provided to at least partially bound the second face  54 . The tertiary teeth  64  may be defined on the side wall  66  either on a terminating free end  68  thereof or along an inside surface  70  thereof. 
         [0018]    At least one of the tertiary teeth  64  is an actuator tooth  72  having a deeper recess  74  than the recesses  76  of adjacent tertiary teeth  64 . In particular, with reference to  FIG. 15 , the actuator tooth  72  defines the deeper recess  74  having a maximum depth D 1  which is greater than the maximum depth D 2  of the adjacent recesses  76 . Preferably, two of the actuator teeth  72  are provided which are located to be diametrically opposite on the body  50  (i.e., evenly spaced about the second dose counter ring  18 ). 
         [0019]    The second dose counter ring  18  also includes at least one actuator through hole  78  formed to extend between, and through, the first and second faces  52 ,  54 . Preferably, an actuator through hole  78  is provided adjacent to each of the actuator teeth  72 . As shown in the Figures, a plurality of actuator through holes  78  may be provided spaced about the body  50 , such as in a circular pattern. 
         [0020]    Indicia  80  are provided on external surface  82  of the side wall  66  useable for counting doses. 
         [0021]    As best shown in  FIGS. 13-14 , the indexer  20  includes a collar  84  formed to be mounted onto the post  26  for rotation therewith. At least one arm  86 , preferably two arms  86 , extend from the collar  84 . With more than one arm, it is preferred that the arms  86  be equiangularly located about the collar  84 . For each of the arms  86 , a drive tab  88  extends upwardly therefrom, with a downwardly extending engagement surface  90  and a downwardly depending secondary tab  92 . The engagement surfaces  90  are located on the arms  86  to engage the tertiary teeth  64  ( FIGS. 7 and 8 ). The actuator through holes  78  are formed to allow passage thereinto of the secondary tabs  92  ( FIG. 7 ). With the engagement surfaces  90  being nestingly received within the deeper recesses  74  of the actuator teeth  72  ( FIG. 6 ), the secondary tabs  92  are provided with sufficient length to pass through the actuator through holes  78  into engagement with the recesses  42  of the first dose counter ring  16 . 
         [0022]    With reference to the Figures, the assembly  10  is formed by stacking in order, within the housing  12 , the first dose counter ring  16 , the second dose counter ring  18 , and the indexer  20  on the post  26 . In this state, simultaneously, the ratchet teeth  40  are in engagement with the first teeth  28  and the ratchet teeth  60  are in engagement with the second teeth  30 , as shown in  FIG. 8 . Also, the indicia  48  and the indicia  80  are aligned so as to be viewable together. The assembly  10  is configured so that one set of indicia  48 ,  80  is viewable at a given instance through the window  22  ( FIG. 2 ). This provides the dose count. With adjustment of the assembly  10 , the indicia  48 ,  80  are adjusted to reflect an updated count. 
         [0023]    In a rest position, the engagement surfaces  90  of the indexer  20  are in engagement with the tertiary teeth  64  ( FIG. 4 ). With the engagement surfaces  90  engaging the tertiary teeth  64  and not the actuator teeth  72 , the actuator through holes  78  are preferably positioned to be spaced below so as to be out of contact with the secondary tabs  92  in a rest state and/or configured and positioned to allow passage thereinto of the secondary tabs  92  in the rest state to avoid contact between the secondary tabs  92  and the second dose counter ring  18  ( FIG. 5 ). 
         [0024]    In operation, rotational force is applied to the drive tabs  88  in a direction with the engagement surfaces  90  pressing against vertical sides  94  of the tertiary teeth  64 . This results in rotational force being applied to the secondary dose counter ring  18 . The second teeth  30  and the ratchet teeth  60  are configured so that in a rest state, angled faces  96  of the second teeth  30  are in engagement with angled faces  98  of the ratchet teeth  60 . With rotational movement imparted to the second dose counter ring  18 , the angled faces  98  are caused to slide along the angled faces  96  in a direction away from vertical faces  100  of the second teeth  30 . This causes the second dose counter ring  18  to rise relative to the base  14 . With sufficient radial displacement, each of the ratchet teeth  60  by-passes an individual of the second teeth  30 . The ratchet teeth  60  then are nestingly received by the next adjacent pair of the second teeth  30 . This incremental adjustment corresponds to individual adjustment of one of the indicia  80  on the second dose counter ring  18 . To re-set the assembly  10  for a further dose counting, the indexer  20  is caused to be rotated in a reverse direction, with the engagement surfaces  90  being caused to by-pass individual tertiary teeth  64 . During this reverse motion, vertical faces  102  of the ratchet teeth  60  engage against the vertical faces  100  of the second teeth  30  thereby preventing reverse rotation of the second dose counter ring  18 . 
         [0025]    As will be appreciated by those skilled in the art, incremental dose counting can be achieved by the assembly  10  by rotation and re-setting of the indexer  20  as described above. With sufficient number of adjustments of the second dose counter ring  18 , the first dose counter ring  16  may be adjusted, such as for example to reflect a change in the tens or one hundreds column. By way of example, the first dose counter ring  16  may in an initial state show the indicia  48  as the number  1  through the window  22  with the indicia  80  on the second dose counter ring  18  being shown incrementally as digits between  9  and  0 . Where the indicia  48  and the indicia  80  collectively show the number “ 10 ”, upon the next counting of a dose, the first dose counter ring  16  may be adjusted to show the digit “ 0 ” and with the indicia  48  and  80  collectively showing “ 09 ”. 
         [0026]    To permit adjustment of the first dose counter ring  16 , the actuator teeth  72  are located to permit adjustment of the first dose counter ring  16  upon a certain number of adjustments of the second dose counter ring  18 . For example, the actuator teeth  72  may be located to permit an adjustment of the first dose counter ring  16  on every tenth adjustment of the second dose counter ring  18 . With the engagement surfaces  90  engaging the deeper recesses  74  of the actuator teeth  72  ( FIG. 6 ), the secondary tabs  92  are caused to pass through the actuator through holes  78  ( FIG. 7 ) and into engagement with the recesses  42  of the first dose counter ring  16 . With rotation of the indexer  20  as described above, rotational forces are imparted to the first dose counter ring  16  due to the interengagement of the secondary tabs  92  and the recesses  42  resulting in the ratchet teeth  40  by-passing an individual of the first teeth  28 , in the same manner described above with respect to the second teeth  30  and the ratchet teeth  60 . Reverse rotation of the indexer  20  causes the secondary tabs  92  to separate from the recesses  42 . Due to the interengagement of the first teeth  28  and the ratchet teeth  40 , inadvertent rotation of the first dose counter ring  16  is avoided. 
         [0027]    As will be appreciated by those skilled in the art, rotational force may be imparted to the drive tabs  88  of the indexer  20  in various manners. By way of non-limiting example, and in a manner like that disclosed in U.S. Pat. No. 6,240,918, a spring retainer  104  may be provided adjacent to the indexer  20  ( FIG. 4 ). The spring retainer  104  is fixed to a portion of an inhaler, as known in the art, which is rotatable relative to the housing  12 . In this manner, the spring retainer  104  may be rotated relative to the assembly  10 . For example, with reference to  FIGS. 1 and 2 , reservoir R is coupled to the spring retainer  104  so as to be rotatable therewith. Rotational force may be imparted to the reservoir R by mounting and dismounting closure cap C, in a manner as disclosed in U.S. Pat. No. 6,240,918. Any arrangement for allowing delivery of medicament from the reservoir R and through nozzle N may be utilized. 
         [0028]    As best shown in  FIGS. 11 and 12 , the spring retainer  104  includes one or more driving ribs  106  configured and located to engage the drive tabs  88  upon rotation of the spring retainer  104  relative to the indexer  20 . As will be appreciated by those skilled in the art, depending on the operation of the associated inhaler, the spring retainer  104  may engage the indexer  24  over a limited range of its motion. 
         [0029]    To ensure that the components of the assembly  10  remain in tight engagement, a spring, or other biasing means,  108  is provided to apply biasing force against the assembly  10  in a direction of the base  14 . Preferably, the spring  108  is located to press against the spring retainer  104 . With the first and second dose counter rings  16 ,  18  rising during displacement, as described above, this motion may be resiliently absorbed by the spring  108 . 
         [0030]    As will be appreciated by those skilled in the art, the first dose counter ring  16  may be used alone, without the second dose counter ring  18 , wherein the indexer  20  is caused to urge the first dose counter ring  16  incrementally about the base  14 . With this arrangement, the tertiary teeth  64  will be provided on the first dose counter ring  16 . The actuating teeth  72  and the actuator through holes  78  are not necessary. 
         [0031]    The indicia  48 ,  80  are preferably arranged to count down the available number of doses so that showing of zero indicates no remaining doses. Colors or other indicia may be used in combination with numbers, or alternatively alone, to indicate the level of remaining doses. For example, colors, such as green, yellow, and red, may be provided to cover ranges of doses with red, for example, providing an alert of low supply. 
         [0032]    A stop  110  may be provided which is engaged by one or both of the first dose counter ring  16  and the second dose counter ring  18  upon a predetermined number of adjustments of the assembly  10  corresponding to a predetermined number of administered doses. For example, as shown in  FIG. 9 , the stop  110  may be located on the base  14  so as to be interferingly engaged by a stop member  112  formed on the first dose counter ring  16  upon a predetermined number of adjustments of the first dose counter ring  16 . This allows for stopping further adjustment, and, thus, stopping further possible dosing. A certain number of extra doses may be provided for the inhaler, beyond the rated amount, to best ensure that the inhaler can provide all doses to be counted. The use of the stop  110  prevents dosing of any residual medicament left beyond the fully counted number of doses.