Abstract:
A nebulizer which is a metered dose inhaler for use in administering medicaments with an associated does counter, which can, by way of a guide track or inclined plane and an associated guide element, cause an axial movement occurring on actuation of the nebulizer to be partly converted into a rotary movement for driving a counting ring, which can count both complete and incomplete actuations.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a nebulizer for dispensing medicament with associated means for counting doses administered by the nebulizer. 
     The present invention preferably relates to nebulisers in the form of inhalers. In particular, the invention relates to so-called Metered Dose Inhalers (MDIs), i.e. inhalers in which a liquid medicament formulation is dispensed as an aerosol, or nebulised, from a pressurised container (aerosol container) by means of a metering valve, in particular. However, the present invention can also be used for other inhalers or nebulisers in which it is important to count the number of doses dispensed. 
     2. Description of Related Art 
     WO 00/09187 A1, which constitutes the starting point, discloses an MDI with a counting device for counting actuations and/or aerosol doses dispensed. On actuation, a container that holds the medicament formulation to be dispensed is pressed into a housing of the MDI. This stroke movement is detected by the counting device and drives a counting ring. For this purpose, the counting device has an elastically deformable drive element resembling a bell-crank lever. When the MDI is actuated, the drive element is moved both axially and in the direction of rotation (circumferential direction) of the counting ring at the same time, so as to rotate the counting ring further. 
     The elastic deformation of the drive element in the known MDI may be problematic. In particular, satisfactory resetting of the drive element is absolutely necessary if problem-free operation of the counting device is to be guaranteed. This requires very narrow manufacturing tolerances. 
     A further problem or disadvantage of the known MDI is the fact that incomplete actuation—i.e. where the container is only partly moved—does not ensure that the counting device or counting ring is reliably moved on, even when a dose is dispensed in spite of only partial actuation. 
     A BRIEF SUMMARY OF THE INVENTION 
     The problem of the present invention is to provide a nebuliser having an improved counting device. 
     The above problem is solved with a nebulizer according to the present invention as described herein. 
     In one aspect of the present invention, the drive device of the counter comprises a first guide track and/or an inclined plane and an associated guide element for converting an axial movement into a rotary movement for driving the counting ring or an associated gearwheel. This allows positive driving or rotating and counting, with elastic deformation of the drive element neither needed nor provided. This allows a construction which is particularly reliable in operation, while avoiding elastic deformation of the drive element. 
     In a second aspect of the present invention which can also be implemented independently, the drive element is annular with axial teeth and/or of rigid construction. This again provides a simple construction which is reliable in operation. 
     In a third aspect of the present invention which can also be implemented independently, the nebuliser or counter is configured such that even a partial actuation of the nebuliser is sufficient to move the counter on. This leads to particularly reliable counting and hence very reliable operation of the nebuliser. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Further advantages, features, properties and aspects of the present invention will become apparent from the following description of a preferred embodiment, by reference to the drawings, wherein: 
         FIG. 1  is a schematic section through a proposed nebuliser with a counter; 
         FIG. 2  is an exploded view of parts of the counter; 
         FIG. 3  is a schematic partial section through the counter without a housing, with the nebuliser actuated; and 
         FIG. 4  is a schematic representation in the manner of a development of a drive device of the counter at the start of actuation of the nebuliser. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the Figures, the same reference numerals are used for identical or similar parts, while corresponding or comparable properties and advantages are achieved even when the description is not repeated. 
       FIG. 1  shows, in a purely schematic section, a preferred embodiment of a nebuliser  1  according to the present invention. The nebuliser  1  is, in particular, an inhaler, preferably an MDI. 
     In particular, the nebuliser  1  is designed to deliver a medicament formulation or a fluid  2  from a container  3  as a spray mist or aerosol  4 , as shown schematically in  FIG. 1 . It should be noted that  FIG. 1  shows the nebuliser  1  in the unactuated state, but the spray mist or aerosol  4  is shown for illustration purposes. 
     In the embodiment shown the nebuliser  1  has a housing  5  into which the container  3  preferably has been inserted or can be inserted. However, other design solutions are also possible. 
     The nebuliser  1  or container  3  preferably comprises a valve  6 , particularly a metering valve. Particularly preferably, the valve  6  comprises a valve element that can be moved in particular to open the valve  6 , particularly a valve stem  7  that can be pressed in axially. However, other design solutions are possible here, too. 
     The nebuliser  1  preferably comprises a spray device or nozzle  8  which is attached to the container  3  or to the valve  6  or its valve element or valve stem  7 —via a connecting member  9  in the embodiment shown—for dispensing the fluid  2  by spraying or for forming the aerosol  4  on actuation of the nebuliser  1 . Preferably, the nozzle  8  is formed by the connecting member  9 , particularly in a side surface of the preferably substantially hollow cylindrical connecting member  9 . However, other design solutions are possible here too. 
     The nebuliser  1  preferably comprises a mouthpiece  10  or other endpiece for delivering the aerosol  4 , which is particularly preferably formed or held by a housing part  11  in the form of an angle member. However, other design solutions are possible here too. 
     The nebuliser  1  or its housing  5  and/or container  3  is or are preferably of elongate construction. The aerosol  4  is preferably dispensed diagonally or at right-angles to this longitudinal direction L. The mouthpiece  10  or other endpiece is preferably correspondingly angled or adapted to be folded away, optionally also adjustable, particularly pivotable. 
     On actuation of the nebuliser  1  the valve  6  is opened and in particular only one dose of the fluid  2  is delivered through the valve stem  7 , the connecting member  9  and the nozzle  8 . In the nozzle  8  the medicament is atomised or nebulised as an aerosol  4  which is dispensed through the mouthpiece  10  or other endpiece. The aerosol  4  can then be inhaled. 
     The actuation of the nebuliser or the opening of the valve is preferably carried out by axially pressing in the valve stem  7  or otherwise actuating the valve  6 . 
     In the embodiment shown, during the actuation of the nebuliser  1 , or for the purpose of actuating it, the container  3  or the valve  6  is or are moved or compressed on the one hand relative to the connecting member  9  or housing part  11  or on the other hand relative to one another, particularly in the direction of the longitudinal axis L, in an axial movement as indicated by the arrow A. In the embodiment shown, this is done by manually pressing the container  3  by its base (at the top in  FIG. 1 ) further into the open housing  5 —in particular counter to the spring force of the valve  6  and/or another spring element. However, the actuation may also be carried out in reverse manner by pressing onto the housing part  11  (angle member) or another actuating part, in which case the housing  5  is then closed off at the top, for example, and the housing part  11  or other part can be slid along, actuated or pressed in relative to the housing  5 . 
     However, other design solutions are also possible for actuating the nebuliser  1 . 
     The axial movement A opens the valve  6 , and a dose of the fluid  2  is dispensed. When the nebuliser  1  is actuated fully, i.e. when there is a complete axial movement A, the container  3  or other actuating member of the nebuliser—such as the housing part  11 , the connecting member  9 , the valve element, such as the valve stem  7 , or the like—executes a stroke H, particularly relative to the valve  6  or housing  5 . 
     Depending on the construction of the nebuliser  1  or valve  6 , the aerosol  4  is often delivered, i.e. a dose of the fluid  2  is dispensed, even when the stroke H is incomplete—i.e. when actuation is incomplete. 
     The nebuliser  1  has a counter  12  for counting actuations of the nebuliser  1  or of doses of aerosol dispensed. The counter  12  is schematically shown in section in  FIG. 1 . It is preferably disposed in or on the housing  5 , particularly the head piece, angle member or housing part  11 , and/or on the top of the container  3 . However, other design solutions are possible here too. 
     The totals counted by the counter  12  can be indicated or read off through a viewing window  13 , which is formed in the housing  5  and/or in the housing part  11  here. 
     The counter  12  may for example indicate the number of aerosol doses still available or the number of actuations that have already taken place or the number of aerosol doses dispensed, as the numerical value displayed. 
     The counter  12  preferably comprises at least one counting ring  14  and/or an associated gearwheel  15 . 
     According to an alternative embodiment, the gearwheel  15  may also form a first counting ring and the counting ring  14  may form a second counting ring. In particular the gearwheel  15  is preferably then coupled to the counting ring  14  via a stepping-down gear (not shown) so that after a certain number of counting steps of the gearwheel  15  the counting ring  14  is then advanced or further rotated by one counting step. 
     If only one counting ring  14  or one additional counting ring is also provided, the gearwheel  15  can be selectively coupled to the counting ring  14  directly or via a stepping down gear or if necessary may even be formed directly by the counting ring  14  or integrally formed therewith. 
     The alternative features mentioned above are particularly preferably also covered by the description or phrase “the gearwheel  15  is associated with the counting ring  14 ”. 
     The counter  12  further comprises a drive device  16  for driving the counting ring  14  or gearwheel  15 , particularly by stepwise rotation, as shown in exploded view in  FIG. 2 . 
     The drive device  16  comprises a drive element  17  which is associated with the counting ring  14  or gearwheel  15  for stepwise further rotation. 
     Preferably, the drive element  17  is at least substantially annular, with axial teeth  18  and/or of rigid construction. The teeth  18  correspond to the teeth  32  on the gearwheel  15 , although there is no need for teeth to be provided over the entire underside of the drive element  17  and/or over the entire surface of the gearwheel  15 . If desired only individual teeth may be provided. 
     In particular, the drive element  17  can be moved first of all towards the counting ring  14  or gearwheel  15  and particularly preferably can only be rotated jointly with them afterwards. 
     Preferably, the nebuliser  1  or counter  12  or the drive device  16  thereof is or are constructed such that even partial actuation of the nebuliser  1  or a partial stroke H is sufficient to move the counter  12  on or rotate the gearwheel  15  or counting ring  14  by one counting step. A possible design solution will become apparent from the more detailed description of a preferred construction of the counter  12  that follows. 
     As an illustration of a preferred construction of the counter  12  and/or the preferred function of the counter  12 , reference is hereinafter made to  FIGS. 2 to 4  in addition to  FIG. 1 .  FIG. 2  shows components or parts of the counter  12  in an exploded view.  FIG. 3  shows, in schematic partial section, a part of the counter  12  with the nebuliser  1  actuated.  FIG. 4  shows in a schematic development parts of the counter  12  or drive device  16  at an initial stage of the actuation of the nebuliser  1 . 
     The counter  12  preferably comprises a counter housing which in this case is made up of a lower part  19  and an upper part  20 . The terms “lower part” and “upper part” are used only for ease of description but do not provide any information as to their orientation when the nebuliser  1  or counter  12  is in used. In addition, other design solutions are also possible. 
     In the counter housing—in the lower part  19  in the embodiment shown—there is preferably a viewing window  21  for displaying or showing the numerical values of the counter  12  so that they can be read off. The viewing window  21  is associated with the window  13 , in particular. For example, the viewing window  21  may be a gap or opening, particularly if the window  13  is transparent but is closed off by a wall. Conversely it is also possible for the viewing window to be closed off by a wall, cover or the like but still be transparent. 
     The counter  12  also preferably comprises a guide part  22  with at least one guide element  23 , in particular two guide elements  23  arranged on opposite sides, and preferably a guide sleeve  24 . 
     The counter device  12  is preferably fitted into the nebuliser  1  or the housing  5  or housing part  11  so as to abut on the container  3  or on a so-called valve plate of the container  3 /valve  6 —with the lower part  19  in the embodiment shown—and/or so as to accommodate or embrace the valve element, such as the valve stem  7 . The connecting member  9  preferably extends through a central opening  25  in the upper part  20  into the counter housing as far as the valve  6  or valve stem  7 . In particular, the connecting member  9  forms a valve stem receptacle and has for this purpose a central bore, recess or the like with a nozzle  8  preferably attached thereto. 
     On actuation of the nebuliser  1  the axial movement A causes the connecting member  9  to penetrate more deeply into the counter housing, in particular it causes the lower part  19  and upper part  20  to be moved along the longitudinal axis L—upwards, in the representation shown in FIG.  1 —relative to the connecting member  9 . The counter housing or upper part  20  preferably has a sector-like peripheral depression  26  in the embodiment shown which broadens radially outwards in the circumferential direction, to ensure that even when the nebuliser  1  is actuated when the connecting member  9  is located deeper in the upper part  20 , the nozzle  8  can deliver the aerosol  4  in the desired manner, laterally in the direction of the mouthpiece  10  or other endpiece. However, other design solutions are possible here too. 
     The guide part  22  preferably fits onto the connecting member  9 . Preferably, the connecting member  9  passes through the guide part  22 . Particularly preferably, this guide part  22  is axially supported on the connecting member  9 , so that during the axial movement A or during actuation of the nebuliser  1 , the guide part  22  cannot be pushed further onto the connection member  9  in the axial direction. This can be ensured for example by a corresponding axial abutment, such as a shoulder  37  which is shown purely schematically in  FIG. 1 . 
     Instead of being supported on the connecting member  9  the guide part  22  may also be supported on a different part of the nebuliser  1 , particularly the housing part  11 . 
     The guide elements  23  preferably extend radially outwards from the guide part  22 , particularly on opposite sides. 
     The guide elements  23  are preferably constructed in the manner of pegs. 
     Where reference is made hereinafter to only one guide element  23 , this is because a single guide element  23  is theoretically sufficient to perform the function, even though preferably two guide elements  23  will be provided on opposite sides for reasons of design, stability and/or safety. 
     The counter  12  or drive device  16  preferably has a first guide track  27  and/or an inclined plane  28  for the guide element  23 , or even, in the embodiment shown, two first guide tracks  27  or inclined planes  28  for the two guide elements  23 . 
     The first guide track  27  or inclined plane  28  is preferably formed in or by the drive element  17 . However, other design solutions are also possible. 
     The guide elements  23  each preferably pass radially through their associated first guide tracks  27  and are preferably each guided by their free ends in second guide tracks  29 , which are preferably formed in or by the guide sleeve  24 . 
     Preferably, the second guide tracks  29  run only in the axial direction. Accordingly, the guide elements  23  are each guided to be movable only in the axial direction relative to the rotation axis of the counting ring  14  or gearwheel  15 . However, other design solutions are possible here as well. 
     Depending on the construction, the guide tracks  27  and/or  29  may selectively be formed as a slot, groove or the like. 
     The guide sleeve  24  is preferably installed in the counter housing so as to rotate therewith. The counter housing is in turn preferably installed in the nebuliser  1  so as to rotate therewith. For this purpose, the upper part  20  comprises, for example, an exterior axial groove  30  into which a radial and/or web-like projection  31  or a spring of the nebuliser  1  or housing  5  or housing part  11  engages, as shown in  FIG. 1 , to create a non-rotational but displaceable connection with the counter housing. However, other design solutions are possible here as well. 
     The gearwheel  15  is provided with preferably axial teeth  32  which take the form of saw teeth, in particular, and/or correspond to the teeth  18  of the drive element  17  such that in the axially contracted state the drive element  17  is able to drive or further rotate or co-rotate the gearwheel  15  at least or only in a direction of rotation D (the counting direction), as shown in  FIG. 3 . 
     Numbers or numerical values, not shown in the Figures, are preferably arranged on the peripheral circumferential surface or other suitable area of the counting ring  14  and/or gearwheel  15  and can be seen from outside through the windows  13 ,  21 , so as to indicate the current total on the counter  12 . 
     The guide track  27  or  29  or the inclined plane  28  preferably forms a slot or a groove in which the associated guide element  23  engages. However, other design solutions are also possible. 
       FIG. 4  illustrates the operating principle of the proposed drive device  16  of the counter  12 . 
     The guide elements  23  are each guided so as to be movable only in the axial direction in the second guide track  29  relative to the rotation axis of the counting ring  14 /gearwheel  15 , i.e. the guide part  22  is secured against rotation. Alternatively or additionally, the guide part  22  may also be held directly on the housing part  11  or connecting member  9  and/or secured against rotation in some other way. 
     When the nebuliser  1  is not actuated, the drive element  17  is preferably axially spaced from the associated counting wheel  14  or gearwheel  15 . When the nebuliser  1  is actuated the axial movement A of the guide elements towards the counting ring  14  or gearwheel  15  takes place. At the start of this axial movement, which is shown in  FIG. 4 , the drive element  17  is initially pushed axially towards the counting ring  14  or the gear wheel  15  so that the teeth  18  and  32  are brought into engagement with one another. This is achieved by the fact that the guide elements act on the drive element  17  via the first guide tracks  27 , and in particular form a slide-like guide or positive guide. Preferably, the guide elements  23  cooperate with the sloping planes  28  such that at the start of the axial movement A initially the drive element  17  is axially moved only or substantially towards the gearwheel  15  until the teeth engage. 
     In the course of the further axial movement A of the guide elements  23  the drive element A is rotated in the direction of rotation D together with the gearwheel  15  that rotates with it as a result of the meshing of the teeth  18  and  32 . 
     Expressed in more general terms, the axial movement A is thus converted into the rotary movement D for driving the counting ring  14  or gearwheel  15  by means of the first guide track  27  and/or the inclined plane  28  and an associated guide element  23  and/or a slide-like guide. 
     Preferably, the inclined plane  28  forms part of the first guide track  27 . Particularly preferably, the inclined plane  28  is formed here by a helical track section. The helical track section in turn preferably forms part of the first guide track. 
     Particularly preferably, the nebuliser  1  or the counting device  12  or the drive device  16  thereof is configured such that even a partial actuation of the nebuliser  1 , i.e. even a partial axial movement A, and in particular only the initial axial movement A, is sufficient for advancing the counting device  12 , i.e. further rotating the counting ring  14  or gearwheel  15  by a numerical value. In the embodiment shown this is achieved by having the first guide track  27  or the inclined plane  28  designed such that adjoining the sloping section or the inclined plane  28  there is optionally an axially extending section  33  of the guide track  27 . In this way it can be ensured that after the initial axial movement A, in the course of the continued axial movement A the drive element  17  and hence also the counting wheel  14  or gearwheel  15  are not rotated further. This ensures that only the initial axial movement A brings about the further rotation and hence advance of the counter. Accordingly, even if there is incomplete actuation of the nebuliser  1 , particularly if the maximum stroke H is not achieved, counting can be continued correctly, as in this case, also, a dose of aerosol is usually delivered by the nebuliser  1 . 
     In the embodiment shown, the slot or groove of the first guide track  27  initially runs at an inclination and then axially, starting from a position of engagement of the guide element  23  shown in  FIG. 4 , with the nebuliser  1  not actuated. 
     It should be noted that in the proposed nebuliser  1  or the proposed counter  12 , the drive element  17  is preferably initially movable only axially towards the counting ring  14  or gearwheel  15  and only afterwards is it rotatable together with the latter. As already stated, this is achieved by means of the first guide track  27  and/or inclined plane  28  and the associated guide element  23 . However, here again, different design solutions and/or procedures are also possible. 
     After the actuation of the nebuliser  1  has ended the axial movement A takes place in the opposite direction. In particular, the guide elements  23  are moved axially away again from the counting ring  14  or gear wheel  15 . This can be assisted by a spring (not shown). This also causes the drive element  17  to be moved axially away from the gearwheel  15 , so that they are moved out of engagement. Moreover, the drive element  17  is then rotated back into its starting position in the course of the continued axial movement back of the guide elements  23 . This is in turn carried out as a result of the corresponding travel of the first guide tracks  27  or inclined planes  28 . The nebuliser  1  is then ready to be actuated again. 
     In the embodiment shown the drive device  16  preferably has two guide elements  23  and/or first guide tracks  27 , particularly on opposite sides, i.e. on two slide-like or positive guides. However, only one such guide may be provided. 
     Particularly preferably, the counter  12  has a barrier or latching device  34  for preventing the counting ring  14  and/or gearwheel  15  from turning backwards and/or for stepwise latching of the counting ring  14  and/or gearwheel  15 . The barrier or latching device  34  in the embodiment shown preferably has a latching arm  35  that is elastically biased against the teeth  32  and/or in the axial direction, which is in particular formed or held by the guide sleeve  32  and/or formed thereon and/or disposed in a peripheral recess  36  in the drive element  17  as shown in  FIG. 3 . 
     However, other design solutions are also possible here. In particular, radial engagement and/or locking in one direction of rotation may also be provided. 
     Particularly preferably, the latching arm  35  together with the saw teeth  32  forms a rotation limiter that allows the gearwheel  15  to rotate in only one direction of rotation, namely the direction D for counting onwards. 
     Particularly preferably, the counter  12  forms a construction unit that can be inserted as a single unit in the housing  5  during assembly of the nebuliser  1 . This makes assembly considerably easier. 
     The proposed counter  12  may also be used in other inhalers or nebulisers  1 . 
     LIST OF REFERENCE NUMERALS 
     
         
           1  nebuliser 
           2  fluid 
           3  container 
           4  aerosol 
           5  housing 
           6  valve 
           7  valve stem 
           8  nozzle 
           9  connecting member 
           10  mouthpiece 
           11  housing part 
           12  counter 
           13  window 
           14  counting ring 
           15  gearwheel 
           16  drive device 
           17  drive element 
           18  teeth (drive element) 
           19  lower part 
           20  upper part 
           21  viewing window 
           22  guide part 
           23  guide element 
           24  guide sleeve 
           25  opening 
           26  depression 
           27  first guide track 
           28  inclined plane 
           29  second guide track 
           30  axial groove 
           31  projection 
           32  teeth (gearwheel) 
           33  axial section 
           34  latching device 
           35  latching arm 
           36  recess 
           37  shoulder 
         A axial movement 
         D direction of rotation 
         H stroke 
         L longitudinal axis