Abstract:
A dose counter device for an inhaler that in a reliable way registers a delivered dose from a canister in the inhaler and that at the same time substantially reduces the risk of falsely registering a dose not delivered substantially avoids erroneous counting of delivered doses from the canister.

Description:
This application is a national-phase application under 35 USC 371 of International Application PCT/SE06/50156 filed on May 23, 2006, and a non-provisional of U.S. Provisional Patent Application No. 60/683,778 filed on May 24, 2005. 
    
    
     TECHNICAL FIELD 
     The invention refers to a dose counter device for an inhaler that in a reliable way will register a delivered dose from a canister comprised in the inhaler, and that at the same time will substantially reduce the risk of falsely register a dose not delivered. Thus, the present invention will in an effective way, substantially avoid erroneous counting of delivered doses from the canister. 
     PRIOR ART 
     Within the field of inhalers, dose counters are known that will count the number of doses delivered from a canister comprised in the inhaler. The user will thus for instance know the number of doses taken or the number of doses remaining in the canister. 
     A problem with known dose counters is that they at times will register a delivered dose that never was delivered, and that they also may miss to register a dose that in fact was delivered. The user of the inhaler is thus provided with false information about the number of doses remaining in the inhaler, which may constitute a major problem for instance an asthmatic person which thus unintentionally may run out of medicament. 
     In EP-A2-0966309, a dose counter is located near the valve region of the canister and attached to the base of an actuator, wherein the displacement of the top of the canister relative to the valve stem is measured. 
     In EP-A1-0254391, a dose counter is located on the top of the inhalation device, wherein the displacement of the top of the canister relative the actuator body is measured. 
     Since canisters suffers from manufacturing height dimension variations and the counters in EP-A2-0966309 and in EP-A1-0254391 works taking into account the displacement of the canister, there exist a great risk for having counting errors. 
     In EP-A2-1131248, a dose counter is located on the top of the inhalation device, wherein the dose counter counts when a given pressure of a spring is achieved, such that the counting is achieved before a dose is given. A drawback with such a counter is that the force of the spring and the counting means must be accurately controlled. 
     Therefore, there is a general need for a dose counter device that in a reliable way will register a delivered dose from a canister comprised in the inhaler, and that at the same time substantially will reduce the risk of falsely register a dose not delivered. As understood, it is very difficult, if not impossible; to construe a device that registers the in fact delivered dose with 100% accuracy. However, from the users&#39; point of view, it is better to have at hand a dose counter device that occasionally may register a dose delivery even though no dose was in fact delivered, than to have it the other way around. In this way, the user can not unintentionally run out of medicament. 
     Further, such a dose counter is known in WO-A1-2006/004496, which discloses a dose counter that is attached and pressed down to a canister in an assembling process until the height of the counter and the canister together is within a predetermined height. The counting is related to the downward motion of the canister and the counter. The combination (dose counter attached and pressed down to a canister) interacts with the valve means of the housing. A drawback with such a counter is that it only compensates for the canisters&#39; manufacturing height dimension variations without taking into account either the manufacturing height dimension variations of the dose counter means or the height dimension variations of the arrangement between the canister and the inhaler housing, which have also the potential to cause miscounting. 
     SUMMARY 
     The aim of the present invention is therefore to provide a dose counter device that satisfies the above described need. 
     This aim is solved by the present invention characterised by claim  1 . Additional advantageous developments of the present invention are characterised by the dependent claims. 
     According to one major aspect of the invention, there is provided a dose counter device for an inhaler adapted to be mounted on the distal end of the inhaler, said inhaler comprises an arrangement wherein a canister is comprised in an inhaler housing, wherein the distal end of the canister protrudes a distance from the distal end of the inhaler housing, and wherein said housing and said distal end of the canister interact with dose counter means to register a delivered dose, wherein the dose counter device is provided with means arranged and designed to calibrate for height dimension variations of said canister, of said dose counter means and of said arrangement and to interact with said counter means to register a delivered dose. 
     This solution provides the advantage that an erroneous counting of the delivered dose from the canister caused by the height dimension variations of said canister, of said dose counter means and of said arrangement is avoided. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a general inhaler comprising a liquid medicament containing canister, when the inhaler is in a non-activated state, 
         FIG. 2  illustrates a calibrating means of the present invention, 
         FIG. 3  illustrates the calibrating means of  FIG. 2 , mounted on top of the inhaler, 
         FIG. 4  illustrates a driving means of the present invention according to a first embodiment, 
         FIG. 5  illustrates a house of the present invention, 
         FIG. 6  illustrates the components of  FIG. 2-5  mounted on top of an inhaler according to a first embodiment, partly seen in cross-section 
         FIG. 7  illustrates the distal end of the dose counter device according to the first embodiment mounted on top of an inhaler, as seen in cross-section from above, 
         FIG. 8  illustrates the components of the dose counter device according to a second embodiment mounted on top of an inhaler in a non-activated state, partly seen in cross-section, 
         FIG. 9  illustrates the dose counter device as seen in  FIG. 8  but in an activated state, 
         FIG. 10-12  illustrates the cooperation between the house and the driving means in three different subsequent stages of the activated state, 
         FIG. 13  illustrates means of the dose counter device that prevent the driving means to be rotated in the wrong direction, 
         FIG. 14  illustrates in an elevated view a non-rotating means according to the second embodiment. 
         FIG. 15  illustrates the components of the dose counter device according to a third embodiment mounted on top of an inhaler in a non-activated state, partly seen in cross-section, 
         FIG. 16-20  illustrates the cooperation between the components of the dose counter device according to a third embodiment mounted on top of an inhaler and the driving means in four different subsequent stages for activation. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to  FIG. 1 , a general inhaler  1  comprises a housing  2  having a mouthpiece  4 , which the user puts in his mouth when a dose of medicament is to be inhaled. The housing  2  of the inhaler is adapted to receive a standard canister  6 , containing liquid medicament, wherein the distal end of the canister  6  protrude a certain distance from the distal end of the housing  2 . The canister comprises a main canister body  8  that is adapted to communicate with a dose chamber  10 . The dose chamber  10  is in turn provided with a hollow spring-suspended transfer tube  12  provided with an outlet  13  in its proximal end. The dose chamber is further provided with an outlet valve  14  that is adapted to correspond to a valve  16  in the transfer tube  12 . The interior of the mouthpiece  4  is provided with a tubular receiving means  18 , having an inward protruding flange  20 , provided a predetermined distance from the bottom of the receiving means  18 . The receiving means  18  is further provided with an outlet  22  that communicates with the outlet of the mouthpiece  4 . 
     The proximal end of the transfer tube  12  abuts against the flange  20 , such that a part of the outlet  13  of the transfer tube communicates with the outlet  22  of the receiving means. 
     When a user of the inhaler intends to inhale a dose, he puts the mouthpiece in his mouth and applies a force, generally by the aid of his hand and fingers or the like, on the distal surface of the canister  6 , such that the canister body  8  and the dose chamber  10  is forced downwards towards the bottom of the housing  2 , i.e. towards the proximal end of the canister, while the transfer tube  12  remains still. Thus, when the dose chamber  10  has moved a predetermined distance towards the bottom of the housing, the valve  16  of the transfer tube  12  will open communication with the valve  14  of the dose chamber, such that a metered dose of the pressurised liquid medicament contained in the main body  8  will flow from the dose chamber  10 , through the valves  14 ,  16 , the transfer tube  12 , the outlets  13 ,  22  and out through the outlet of the mouthpiece  4 . When the user releases the force applied to the distal end of the canister, the canister will move back to its original position. 
     The distance between the valves  14 ,  16  is a known predetermined distance, generally 2 mm, when the inhaler is in the first non activated state, i.e. the dose chamber needs to in a second activated state be forced downwards with a distance of 2 mm for the valves  14 ,  16  to open communication with each other. It would be a simple case to construe a reliable dose counter device if the dimensions of the inhaler, would be exact dimensions. However, all dimensions of the general inhaler, such as the height of the main body A, the height of the dose chamber B, the length of the transfer tube C, the distance between the proximal end of the transfer tube and the distal edge of the housing D and the height of the dose counter means, are impaired by variation of not neglectable magnitude. If for instance the variation of the distances A, B, C, D is ±0.4 mm, ±0.05 mm, ±0.25 mm, ±0.2 mm, respectively and the variation of height of dose counter means is ±0.1 mm, the sum of all margins of errors will be ±1 mm. So, if one for instance construes a dose counter device that determines the distance that the canister has moved towards the bottom of the housing, dependent on a single reference point, for instance the distal edge of the housing  2 , and register a delivered dose when said distance amount to 2 mm, the dose may or may not have been delivered. Also, the dose may have been delivered without the distance amounting to 2 mm. 
     The solution to this problem, is according to a first and a second embodiment of the present invention an all mechanical solution, and is based on the idea, that during manufacturing of the dose counter device one establishes a fix known reference point, or reference distance that permits to determine an accurate distance that the canister has to be displaced within an inhaler before a delivered dose is registered. This offers a dose counter that compensates for the height dimension variations of the canister, the means of the dose counter and the arrangement between the canister and the inhaler housing, whereby erroneous counting of delivered doses from the canister is avoided. 
     In  FIG. 2  is shown a calibrating means  36  of the dose counter device, having a sleeve-formed configuration. The interior of the calibrating means has inward preferably equally distributed protruding ribs  38  extending along the longitudinal axis of the means  36 . The ribs  38  preferably have a triangular shape and are manufactured of an easily deformable plastic material. The outer surface of the proximal end of the means  36  is provided with preferably two equally distributed outward protruding pins  40 . 
     The calibrating means  36  is adapted to be mounted over the distal end of the inhaler housing  2 , as seen in  FIG. 3 . The ribs  38  will during this mounting procedure deform and break and the calibrating means will thus be tightly and not removably fitted on the inhaler housing  2 . This mounting procedure is a well controlled process so that the distance between the distal end of the calibrating means  36  and the distal end of the canister  6 , when the mounting procedure is finished, is a well defined and predetermined distance, indicated in  FIG. 3  by the letter E. 
     In  FIG. 4  is shown a component adapted to be used in the present invention according to a first embodiment. Said component is a driving means  42  having a sleeve-formed configuration designed in accordance with the calibrating means  36 . The interior surface of the means  42  is at its proximal end provided with a means (not shown) that corresponds to a means (not shown) on the exterior surface at the proximal end of the calibrating means, so that the driving means is adapted to be fitted over the calibrating means and at a place adapted to be rotated but not be movable along the longitudinal axis of the calibrating means. 
     The exterior surface of the driving means  42  is further provided with a thread  44 , preferably having a variable pitch of grooving. As seen in  FIG. 4 , the pitch of grooving is finer towards the distal end of the driving means. The exterior surface of the distal end of the driving means is further provided with a number of equally distributed pins  46  having a bevelled edge at their distal end. The driving means is further at its distal end provided with upward protruding pins  50 . The pins  50  are at their distal end provided with triangularly shaped teeth  52  protruding towards the interior of the driving means. 
     The driving means  42  of the first embodiment is adapted to be fitted in the interior of a house  54  shown in  FIG. 5 . The house is provided with a dose window  56 , and means that corresponds to the pins  40  of the calibrating means. In order for the driving means  42  to be fitted in the house  54 , the inner surface of the distal end of the house is thus provided with a means that corresponds to the means provided on the distal end of the driving means. So when the dose counter device according to the first embodiment is to be used, the driving means  42  is mounted in the interior of the house  54 , and the two components are mounted over the calibrating means already fitted with the inhaler housing, see  FIG. 6 . 
     In  FIG. 6  it is shown that the interior surface at the distal end of the house  54  is provided with a downward protruding flange  58 , adapted to be in contact with the distal end of the canister  6 . That is, when the dose counter is mounted and ready for use, the distance between the distal end of the calibrating means and the distal end of the canister  6 , i.e. the proximal edge of the flange  58  and the distal end of the calibrating means is a known predetermined distance, i.e. the distance E. 
     When the user of the inhaler intends to inhale a dose, he applies a force on the distal end of the house  54 , which thus moves towards the proximal end of the canister. The flange  58  will thus urge the canister downwards. The flange  58  is further provided with outwardly protruding triangularly shaped teeth  60 , which correspond to the teeth  52  of the driving means, as seen in  FIG. 6  and in  FIG. 7 , wherein the latter illustrates a cross section of the distal end of the dose counter device when mounted on top of an inhaler. The interior surface of the distal end of the house is further provided with inward protruding pins  62  having a bevelled edge at their proximal end that corresponds to the bevelled edge of the pins  46  on the driving means. When thus the house  54  is urged downwards, the bevelled edge of the pins  62  will move along the bevelled edge of the pins  46  and urge the driving means to rotate in the direction indicated by the arrow F in  FIG. 7 . Since the height between the proximal end of the flange  58  and the distal end of the calibrating means is a known distance, i.e. the distance E, the dose counter device is so designed that the distance that one tooth  52  has to move in order to for its tip to meet the tip of a tooth  60  of the house  54  is a known predetermined distance that corresponds to a predetermined distance that the canister body then has moved towards the proximal edge of the inhaler. In this particular embodiment said distance is 1 mm. This is due to the fact that, when the user has pressed the canister downwards this particular distance, one can be pretty certain that he is to inhale a dose and that the downward movement of the canister was not as a result of general handling of the inhaler. Thus, when the two tips of the teeth  52 ,  60  meet, the tooth  52  will inevitably slide over the tooth tip  60  and the dose counter device has thus rotated one step and has accordingly registered a delivered dose. A more detailed description of the cooperation between the pins  46  and  62  is provided below in connection with the  FIGS. 10-12 . 
     The driving means is thus rotated one step when the house is applied with a force on its distal end that will urge a tooth  52  to slide over a tooth  60 . A dose indicating means  64  is provided over the thread  44  but provided in the dose window  56 . The means  64  thus rides along the thread when the driving means is rotated and moves down towards the proximal end of the dose window, indicating the dose remaining in the canister. In  FIG. 5 , the dose scale is seen provided as a progressive scale that corresponds to the variable pitch of grooving of the thread, but naturally the thread can have a non-variable pitch of a grooving, that corresponds to a non-progressive dose scale. 
     Preferably spring means (not shown) is provided between the inner distal end of the house and the distal end of the canister so that the house springs back towards the distal end of the inhaler when the user releases the force applied to the distal end of the house. 
     According to a second embodiment of the present invention, the driving means and the interior of the house have slightly different configurations. In the following description of the second embodiment of the invention, components having essentially the same function as in the first embodiment but having a different configuration, have been designated the same reference number as in the first embodiment followed by a ′-sign. Components having essentially the same function and also essentially the same configuration, have accordingly been designated the same reference number as in the first embodiment. New components have naturally been designated new reference numbers. 
     The driving means of the second embodiment, seen in  FIG. 8 , has thus accordingly been designated the reference number  42 ′. The driving means  42 ′ is adapted to be mounted over the calibrating means  36  as in the first embodiment. The difference between the driving means of the first and second embodiment, respectively, can be seen at the distal end of the driving means. Instead of having the upward protruding pins  50 , provided with the inwardly protruding triangularly shaped teeth  52 , the driving means  42 ′ is provided with an upward protruding crown  66 . The crown is in turn on its distal edge provided with equally distributed upwardly protruding triangularly shaped teeth  52 ′. 
     As in the first embodiment, the driving means  42 ′ is adapted to be fitted inside the house  54 ′. The difference between the house of the first and the second embodiment, respectively, is that no outward protruding triangularly shaped teeth  60  are provided in the house  54 ′. Instead, a non-rotating means  68  is provided in the distal end of the interior of the house  54 ′, overlaying the driving means  42 ′ and the crown  66 . The proximal edge of the non-rotating means is provided with downward protruding triangularly shaped teeth  60 ′, that correspond to the teeth  52 ′ of the driving means  42 ′. 
     The non-rotating means is provided as being suspended by a spring  70 . The spring  70 , preferably a helical steel spring is thus mounted between the inner distal surface of the house  54 ′ and the top of the non-rotating means. The non-rotating means  68  is not provided as a solid means but is provided with through going openings  72 . The number of openings  72  is in this particular embodiment four, such that the non-rotating means  68  when seen from above as in  FIG. 14 , can be seen as a means having a circular circumference provided with the openings  72  in the interior of the means. The demarcations between said openings thus constitute a cross-like shape. The spring  70  is thus provided as to operate between the centre of the cross  76  and the centre of the distal inner surface of the house  54 ′. The downward protruding flange  58 ′ of the house  54 ′ is thus designed in accordance with the non-rotating means  68 , such that when it is forced towards the proximal end of the inhaler, it is adapted to come in contact with the distal edge of the canister through the openings  72  of the means  68 . 
     So, in the second embodiment when thus the house  54 ′ is urged downwards, the bevelled edge of the pins  62  of the house  54 ′ will move along the bevelled edge of the pins  46  and urge the driving means to rotate in the direction indicated by the arrow F in  FIG. 9 . The movement of the driving means to the left as seen in  FIG. 9 , will thus result in that a tip of a tooth  52 ′ also will move to the left urging the spring-suspended non-rotating means  68  up towards the distal end of the inhaler. Since the height between the proximal end of the flange  58 ′ and the distal end of the calibrating means is a known distance, i.e. the distance E, the dose counter device is so designed that the distance that one tooth  52 ′ has to move in order to for its tip to meet the tip of a tooth  60 ′ is a known predetermined distance and that corresponds to a predetermined distance that the canister body then has moved towards the proximal edge of the inhaler. When a tip of a tooth  52 ′, meets a tip of a tooth  60 ′, the canister body has in this particular embodiment moved 1 mm towards the proximal end of the inhaler. This is due to the fact that when the user has pressed the canister downwards this particular distance, one can be pretty certain that he is to inhale a dose and that the downward movement of the canister was not as a result of general handling of the inhaler. Thus, when the two tips of the teeth  52 ′,  60 ′ meet, the tooth  52 ′ will inevitably slide over the tooth tip  60 ′ and the dose counter device has thus rotated one step and has accordingly registered a delivered dose, as described in connection with the first embodiment. 
     In  FIGS. 10-12 , is seen the cooperation between the inward protruding pins  62  of the house  54 ,  54 ′ and the pins  46  on the driving means  42 ,  42 ′. The cooperation between the pins  62  and the pins  46  is the same in the first and the second embodiment, respectively, that is, said figures can be read also in connection with the first embodiment even though the non-rotating means  68  and its cooperation with the driving means  42 ′ is illustrated in the figures. Now turning to  FIG. 10 ; when the house  54 ,  54 ′ is urged downwards, the bevelled edge of the pins  62  will move along the bevelled edge of the pins  46  and thus urge the driving means to rotate in direction indicated by the arrow F. In  FIG. 11  is shown when the tip of a  52 ′ has met the tip of a tooth  60 ′, i.e. the non-rotating means is rotationally fixed but is moved towards the distal end of the canister against the spring force  70  as the tooth tip  52 ′ moves in the direction F. The distance that one tooth tip  52 ,  52 ′ has to move in order to meet a tooth tip  60 ,  60 ′ is designed so that it is in conformity with the predetermined distance that the pins  62  move towards the proximal end of the inhaler until a dose is registered as delivered, in this particular embodiment 1 mm. This is accomplished by for instance providing the bevelled edge of the pins  46  and  62  with the correct inclination, i.e. the correct value of the angle α. 
     In  FIG. 12  is shown when one tooth tip  52 ′ has slid passed the tooth tip  60 ′, with which tip it was previously in contact with. Due to the spring  70 , the non-rotating means will now be urged back downwards to its original position. As previously mentioned, when one tooth tip  52 ,  52 ′ has slid passed its corresponding tooth tip  60 ,  60 ′ a dose is registered as delivered. The user however, continues to urge the house and thus the canister towards the proximal end of the inhaler until the dose is actually delivered. The user then releases the force applied to the distal end of the house  54 ,  54 ′, whereupon the canister and the house will move back to their original positions. Due to the one step rotation of the driving means  42 ,  42 ′, a pin  62  will the next time a dose is to be delivered, cooperate with the pin  46  following the pin it just previously cooperated with. 
     The dose counter device is further preferably provided with means that prevent that the driving means is rotated in the wrong direction, which will result in a wrongful indication about the remaining doses in the canister. In  FIG. 13  is seen one embodiment of such wrong rotation direction preventing means  74 . The means  74  is here illustrated and described in connection with the second embodiment but as the skilled person readily understands, such means  74  can with minor adjustments very well be functional also with the first embodiment. 
     In  FIG. 13 , the wrong rotation direction preventing means  74  can be seen as a slightly different configuration of the teeth  52 ′. The sides of teeth in line with the rotation direction F are unchanged. The other sides of the teeth however, do no longer have an even slope, but are provided with an upward protruding edge  74 , i.e. the teeth  52 ′ no longer have a triangular shape but the shape as seen in  FIG. 13 . The distal tip of the edge  74  now takes over the function of the tip of the tooth  52 ′. The driving means  42 ′ is in an effective way prevented to be rotated in the direction opposite to the direction F by means of the edge  74 . That is, a tooth  60 ′ can not slid pass such an edge  74  if the driving means is rotated in the direction that is opposite the rotation direction F. 
     Further, the solution to the mentioned problem in the introduction part, is according to a third embodiment of the present invention an all mechanical solution, and is based on the idea, that an actuating means, when depressed, travels a longitudinal distance until it makes contact with the distal end of the canister, to then interact with an intermediate means before a dose counter registers a delivered dose. This offers a dose counter that compensates automatically for the height dimension variations of the canister, the means of the dose counter and the arrangement between the canister and the inhaler housing, whereby erroneous counting of delivered doses from the canister are avoided. 
     According to a third embodiment of the present invention, the driving means and the interior of the house have slightly different configurations. In the following description of the third embodiment of the invention, components having essentially the same function as in the second embodiment but having a different configuration, have been designated the same reference number as in the second embodiment followed by a ″-sign. Components having essentially the same function and also essentially the same configuration, have accordingly been designated the same reference number as in the second embodiment. New components have naturally been designated new reference numbers. 
     The driving means of the third embodiment, seen in  FIG. 15 , has thus accordingly been designated the reference number  42 ″. The driving means  42 ″ is adapted to be mounted inside the house  54 ″. The difference between the driving means of the second embodiment and third embodiment, respectively, can be seen at the interior surface of the driving means wherein the distal end of the driving means  42 ″ has a larger diameter than the rest of the driving means  42 ″. Further, the driving means  42 ″ is adapted to be mounted over the distal end of the inhaler housing  2  on a flange  55  at the proximal end of the house  54 ″. 
     As in the second embodiment, the driving means  42 ″ is adapted to be fitted inside the house  54 ″. The difference, seen in  FIG. 16 , between the house of the second and the third embodiment, respectively, is that no inward protruding pins  62  are provided on the interior surface of the distal end of the house, that the distal part of the house has a larger diameter than the rest of the house  54 ″, that a through hole is provided at its top, that a slot  76  is provided in the interior surface at the distal end of the house and that slots  77 , seen in  FIG. 15 , are provided in the interior surface at the distal end of the house. 
     In the third embodiment, seen in  FIG. 15 , the housing  2  is provided with preferably two equally distributed outward protruding pins  40  abutting against the slots  77  of the house  54 ″, instead of having those on the calibrating means  36 . Further, in the third embodiment none calibrating means is required. 
     As seen in  FIG. 16 , an intermediate means  69  is provided at its top with a through hole wherein said through hole has a certain diameter and height. Said through hole may be provided with friction means as a ribbed interior surface or other types of engage means on its interior surface. Further, said intermediate means  69  is provided on its interior surface with an inward flange  83  and with inward protruding pins  75  having a bevelled edge that corresponds to the bevelled edge of the pins  46  on the driving means  42 ″. The through hole of said intermediate means  69  has a slightly smaller diameter that the through hole of the house  54 ″. An outward flange  85  at the top of the intermediate means  69  abuts against the interior surface of the house  54 ″ wherein the edges of the through holes suit each other. Further, said intermediate means  69  is provided on its exterior surface with an outward protruding ledge or pins  78  that corresponds to the slot  76  of the house  54 ″. 
     As seen in  FIG. 16 , an spring  79 , preferably a helical steel spring is mounted in the slot  76  of the house  54 ″ between the outward protruding ledge or pins  78  of the actuating means  69  and a flange of the slot  76  at its distal end. Further, the spring  79  may instead be mounted between the actuating means  69 , surrounding the outward flange  85  at the top of the intermediate means  69  and the interior surface of the top of the house  54 ″ (not shown). 
     As seen in  FIG. 16 , an actuating means  71  is provided as a longitudinal sleeve  87  having bending walls of certain diameter and height. Said longitudinal sleeve  87  being of a flexible material may be provided with friction means as a ribbed exterior surface on its bending walls or with other types of engage means on the exterior surface of its bending walls, as seen in  FIG. 18 . Further, said actuating means  71  is arranged with an outward flange  80  having a slot  81  and a longitudinal extending sleeve  82  of certain diameter and height surrounding the canister  6 . Further, said outward flange  80  abuts against the inward flange  83  of the intermediate means  69 . 
     As seen in  FIG. 16 , a non-rotating means  68 ″ is provided in the distal end of the interior of the house  54 ″, overlaying the driving means  42 ″ and the crown  66 . The proximal edge of the non-rotating means is provided with downward protruding triangularly shaped teeth  60 ′, which correspond to the teeth  52 ′ of the driving means  42 ″. The distal edge of the non-rotating means is provided with a slot  86 . 
     The non-rotating means  68 ″ is provided as a ring being depressed by a spring  73 . The spring  73 , preferably a helical steel spring is thus mounted between the slot  81  of the actuating means  71  and the slot  86  at the distal edge of the non-rotating means  68 ″. 
     In the first and the second embodiments, the calibrating means  36  is adapted to be mounted over the distal end of the inhaler housing  2 . This must be a well controlled mounting procedure so that the distance between the distal end of the calibrating means  36  and the distal end of the canister  6 , is a well defined and predetermined distance, as indicated in  FIG. 3  by the letter E. This is not required in the third embodiment, since the actuating means  71  interacts with the intermediate means  69  and performs the calibration. 
     So, in the third embodiment when the actuating means  71  is urged downwards, the spring  73  will be depressed and the spring  79  will urge the intermediate means  69  to move downward until the bevelled edges of the pins  75  will make contact with the bevelled edges of the pins  46 , as seen in  FIG. 17 . The outward flange  85  will come out of contact from the interior surface of the house  54 ″ and the actuating means  71  will continue to move downward until the outward flange  80  makes contact with the distal edge of the canister. Then, the longitudinal sleeve  87  will bend its bending walls outwardly until its friction or engage means make contact with the friction or engage means of the intermediate means&#39;s through hole, as seen in  FIG. 19 . This contact or engagement, will urge the intermediate means  69  to continue its downward movement until the bevelled edges of the pins  75  will move along the bevelled edges of the pins  46  and urge the driving means  42 ″ to rotate in the direction indicated by the arrow F in  FIG. 20 . The movement of the driving means to the left as seen in  FIG. 20 , will thus result in that a tip of a tooth  52 ′ also will move to the left urging the spring-suspended non-rotating means  68 ″ up towards the distal end of the inhaler. 
     The dose counter device is designed so that the distance that one tooth  52 ′ has to move in order to for its tip to meet the tip of a tooth  60 ′ is a known predetermined distance and that corresponds to a predetermined distance that the canister body then has moved towards the proximal edge of the inhaler. When a tip of a tooth  52 ′, meets a tip of a tooth  60 ′, the canister body has in this particular embodiment moved 1 mm towards the proximal end of the inhaler. This is due to the fact that when the user has pressed the canister downwards this particular distance, one can be pretty certain that he is to inhale a dose and that the downward movement of the canister was not as a result of general handling of the inhaler. Thus, when the two tips of the teeth  52 ′,  60 ′ meet, the tooth  52 ′ will inevitably slide over the tooth tip  60 ′ and the dose counter device has thus rotated one step and has accordingly registered a delivered dose, as described in connection with the first embodiment. 
     Although the present invention has been described with reference to preferred embodiments, those skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. As such, it is intended that the foregoing detailed description be regarded as illustrative rather than limiting and that it is the appended claims, including all equivalents thereof, which are intended to define the scope of the invention.