Abstract:
The invention relates to a step-by-step mechanism, particularly for hand-held devices for the portioned delivery of medicaments to be inhaled, comprising a graduated collar, which can be moved during an actuation stroke and which encircles the center axis of the housing. In order to provide a step-by-step mechanism of the aforementioned type with a more reliable operation while, in a spatially advantageous manner, having a simplified design, the invention provides that the switching finger(s) are permitted to slope upward from a hub located in the center.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     The present application is a continuation of pending International patent application PCT/EP2005/055823 filed on Nov. 8, 2005 which designates the United States and claims priority from German patent applications Nos. 10 2004 054 179.5 filed on Nov. 10, 2004 and 10 2005 033 398.2 filed on Jul. 18, 2005. All prior applications are herein incorporated by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The invention relates to a step-action indexing mechanism according to the preamble of the main claim.  
       BACKGROUND OF THE INVENTION  
       [0003]     Such step-action indexing mechanisms e.g. configured in accordance with GB 1317315, are used in particular in medical aerosol therapy for the treatment of respiratory conditions. A pressurized cartridge located in the unit contains the medicament which is to be inhaled. In order for the latter to be expelled, it is necessary for the cartridge to be displaced axially in the unit. The unit, which usually more or less fully encloses the cartridge, also conventionally has a mouthpiece and/or an adapter for inhaling through the nose. It is necessary to provide the user with a counter for indicating the quantity of medicament which has been used or is still present in the cartridge. Since a defined quantity of medicament is discharged upon each cartridge actuation, it is known for the medicament is discharged upon each cartridge actuation, it is known for the counter to be coupled to the axial displacement of the cartridge in the inhaler housing for the purpose of discharging medicaments. The generically determined solution, which is known for this purpose, is too large to be accommodated in normal units. Moreover, it is difficult to assemble, in particular in respect of the step-action indexing fingers, which are mounted on transverse pins in relation to the step-action indexing-mechanism housing and are to be loaded by separate springs. The counting accuracy which can be achieved is insufficient for use with medicaments. Upon insertion or removal, e.g. for cleaning purposes, incorrect counting can easily take place such that the step-action counter counts a step which did not actually constitute a dispensing step in the inhaler.  
         [0004]     An inhaler appliance is known from EP 480488 with an upper cap which is displaceable in the direction of a cartridge, which cap surrounds an annular part from which there extend obliquely, oppositely-directed resilient step-action indexing fingers, the ends of which engage in a toothed rim, when the cap is pushed in the direction of the cartridge, so that the linear displacement of the cap is converted into a rotational movement of a scale ring. The rotation of the scale ring is visible through a window provided on the cap. The solution is costly and is in particular very disadvantageous in respect of cleanability.  
         [0005]     It is also the case elsewhere that there is a need for straightforwardly constructed counters which operate independently.  
         [0006]     In respect of the above described prior art, a technical problem addressed by the invention is considered as that of configuring a step-action indexing mechanism of the type in question in a spatially advantageous manner, along with simplified construction, such that it is more reliable to handle.  
       SUMMARY OF THE INVENTION  
       [0007]     This problem is solved first and foremost by the subject matter of claim  1 , this being based on an annular housing with indexing members which encircle axes positioned in the longitudinal direction of the housing. The step-action indexing mechanism fits in front of the lower end of corresponding (standard) cartridges of a medicament inhaler and can enclose the outlet tubule thereof. The construction selected requires only a very small amount of space and is also formed advantageously as far as cleaning possibilities and moreover as far as handling during cleaning are concerned. For all practical purposes, counting is not possible outside the inhaler or the like. Functioning is ensured merely by purely mechanically interacting components which, in addition, may further preferably consist of a single plastics material. This helps to simplify production, in particular as far as assembly is concerned. The indexing mechanism is completely independent, that is to say it need not be carried along by other parts, such as a cartridge. These indexing fingers also execute the return movement following actuation.  
         [0008]     The subject matters of the rest of the claims are explained in relation to the subject matter of the main claim, and present advantageous developments.  
         [0009]     It is thus further provided that the step-action indexing mechanism has a concentrically encircling ring with a scale on its outside, the ring being rotated, via a planet-gear mechanism, by a likewise concentrically encircling toothed rim which is driven by the actuating stroke. The rotary movement of the scale ring is derived from a relative displacement of the step-action indexing mechanism. The indexing finger of the latter operates on a path around the center. All that is required is to provide a supporting portion for the indexing-finger hub. In the case of the step-action indexing mechanism possibly being removed from a unit, accidental actuation of the step-action indexing mechanism is not possible on account of the supporting portion for the indexing finger no longer being present. The step-action indexing mechanisms can be packed, and sold, as bulk goods. Furthermore, it is provided that the planet gear is mounted in a bore of the scale ring, and the associated sun gear is seated on a disk which is toothed on the underside. This disk is in engagement with the indexing finger. Furthermore, a latching finger engages in the toothing formation in order to secure the rotary position of the disk which has been reached in each case. The sun gear and toothed disk are preferably formed as a single part, with coaxial alignment. The planet-gear mechanism preferably passes on the angle of rotation to the scale ring in stepped-down form. 200 or 300 stroke actions can correspondingly be shown on the scale ring. It is further preferred if the graduated scale of the scale ring, the scale being disposed on the outer lateral surface of the scale ring and extending in front of a viewing window of the housing, corresponds in each case to a number of individual rotary steps of the planet gear. In this respect, it proves to be advantageous, furthermore, if, as far as the step-down transmission is concerned, an individual rotary step of the planet gear takes place following a number of individual rotary steps of the sun gear. The planet gear, furthermore, is in engagement, in the radially outward direction, with a toothed rim. This arrests the respective rotary position of the scale ring. A slot which extends, directed obliquely upward, from the lower peripheral edge, for the insertion of the step-action indexing finger, is provided in order to predetermine thereby the indexing direction of the finger for rotating the disk on the sun gear further in a stepwise manner. The step-action indexing finger or fingers is or are a constituent part of a step-action indexing-finger star, which has a central hub on which step-action indexing fingers are integrally formed, these fingers being located diametrically opposite one another at a radial spacing from the hub. This step-action indexing-finger star is preferably formed in one piece, preferably from a plastics material. The step-action indexing fingers are directed to extend obliquely upward from the hub, the step-action indexing fingers, furthermore, moving in the direction of a plane perpendicular to the longitudinal axis during the actuating stroke. Accordingly, the step-action indexing fingers are subjected to stressing during the dispensing movement, i.e. during the displacement, for example, of a cartridge along its longitudinal center axis. The step-action indexing-mechanism housing as a whole moves in this case. When used in normal inhalers, the hub of the step-action indexing-finger star can be seated on the end surface of the supporting portion on the hand-held-unit housing. This supporting portion then has a dual function: on the one hand, it functions as a triggering element in conjunction with the valve tube of the cartridge and, on the other hand, the supporting portion has the function of an abutment for the step-action indexing-finger star. This means that there is no possibility at all of actuating the step-action indexing mechanism outside a unit. The step-action indexing-mechanism housing with the rest of the indexing members is displaced relative to the step-action indexing-finger star, this involving movement of the step-action indexing fingers into the plane oriented perpendicularly to the longitudinal axis, which gives rise to the above described prestressing of the step-action indexing fingers and the advancement of the counter. Following release of the actuating pressure, the fingers return into their starting position again. This is achieved by the prestressed step-action indexing fingers which automatically resume their original, obliquely upwardly directed position and, in the process, force the indexing members and the step-action indexing-mechanism housing into their original positions. Correspondingly, in respect of the return displacement into a starting position, the step-action indexing mechanism is decoupled from the cartridge. It has a restoring spring formed by the step-action indexing fingers. It is preferable for the entire step-action indexing mechanism, together with the scale ring, to be enclosed in a round housing, which once again proves to be advantageous in respect of the desired cleaning of the housing. There are no gear-mechanism parts exposed which could be damaged during cleaning, for example by brushing. Rather, a compact, substantially closed construction is selected. In this respect, it is further proposed that the step-action index-mechanism housing, which is configured as a flat plate, has a central hole for the through-passage of a component. It is also possible, in addition, for the step-action index-mechanism housing to be secured—as is known—on the cartridge in the center, beneath the end wall at the opening end and so as to overlap the cartridge valve tube, by resilient latching. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     The invention will be explained in more detail hereinbelow with reference to the accompanying drawing, which merely illustrates various exemplary embodiments and in which:  
         [0011]      FIG. 1  shows, in exploded perspective illustration, the step-action indexing mechanism for the step-action indexing mechanism according to the invention;  
         [0012]      FIG. 2  shows a cross-section through the step-action indexing mechanism;  
         [0013]      FIG. 3  shows a longitudinal section through a hand-held inhaler unit with a schematically illustrated step-action indexing mechanism latched on the cartridge thereof;  
         [0014]      FIG. 4  shows a sectional illustration corresponding to  FIG. 3 , but relating to a different solution, in which the schematically illustrated step-action indexing mechanism is latched on a housing;  
         [0015]      FIG. 4   a  shows a modified embodiment in a sectional illustration according to  FIG. 4 , in the case of which the step-action indexing mechanism in an inhaler is blocked against being pulled out; and  
         [0016]      FIG. 5  shows a longitudinal section through an inhaler with step-action indexing mechanism inserted, following separation of an upper inhaler housing part from its mouthpiece. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]     The hand-held unit  1  which is shown in a schematic sectional illustration in  FIG. 3  serves for apportioned delivery of sprayable substances, in particular inhaler medicaments.  
         [0018]     For this purpose, the hand-held unit  1 , in the first instance, has a hand-held-unit housing  2  into which a cartridge  3  containing the sprayable substance can be inserted. This cartridge  3  is axially displaceable in the housing  2 . In conventional manner, the cartridge head  4  has a central valve tube  5 , which extends coaxially in relation to the cartridge  3 . A delivery of medicament is achieved via this valve tube by an axial relative movement between the cartridge  3  and housing  2 . The inhaler housing  2  is in two parts and comprises two annular parts  6  and  7  which are disposed one above the other and of which the upper annular part  6  is formed as a passageway and the lower annular part  7  has a mouthpiece  8  oriented approximately transversely to the extent of the passageway. This mouthpiece can be closed by a covering cap (not illustrated). The valve tube  5  of the cartridge  3  is supported in an associated tubular supporting portion  9  within the lower annular part  7 , it being possible for the cartridge  3  to move axially within the passage-form annular part  6 , which surrounds the cartridge  3 . The supporting portion  9 , which accommodates the valve tube  5  of the cartridge  3  with clamping action and is formed within the lower annular housing part  7 , is provided with a flow channel  10  which has a smaller diameter than a portion accommodating the valve-tube end and is connected to the valve tube  5  in terms of flow, that end of the flow channel  10  which is directed away from the valve tube  5  being oriented in the direction of the mouthpiece  8 .  
         [0019]     A step-action indexing mechanism  11  is disposed centrally beneath the opening-side end wall of the cartridge  3 , so as to overlap the cartridge valve tube  5 . This indexing mechanism serves for registering and/or counting/indicating the dispensing actuations which have been executed, in dependence on the opening strokes of the cartridge  3  which have been executed.  
         [0020]     The step-action indexing mechanism  11  is shown in  FIG. 1  in an exploded perspective illustration. The central constituent part of the step-action indexing mechanism  11  is a planet-gear mechanism  12  consisting of a planet gear  13 , a sun gear  14 , which is seated on a disk  15  which is toothed on the underside, and a toothed rim  16 , which interacts with the planet gear  13  with arresting action. This toothed rim is formed on the inner wall of a ring  17  which is in the form of a tube portion and is secured such that it cannot be rotated. The lateral wall  18  of the ring  17  has slots  19  passing through it in diametrically opposite regions, these slots extending, directed obliquely upward, in the indexing direction and opening out downward in the direction of the annular edge which is directed away from the toothed rim  16 .  
         [0021]     The toothed rim  16  extends axially approximately over half the height of the ring  17 , the lateral wall  18  of which, being stepped in the direction of the annular end edge which is directed away from the toothed rim  16 , tapers radially.  
         [0022]     Beneath the toothed rim  16 , a latching finger  20  is integrally formed on the inside of the lateral wall  18  of the ring  17 . This latching finger, as seen in a plan view of the ring, is offset radially inward in relation to the toothed rim  16 , and correspondingly engages in a circular space located radially inside the toothed rim  16 . Furthermore, the arrangement of the latching finger  20 , which is of elastic formation approximately in the vertical direction, is selected such that this finger engages approximately in a horizontal plane defined by the lower peripheral edges of the toothed rim  16 .  
         [0023]     The diameter of the disk  15 , which carries the sun gear  14 , is selected to be slightly smaller than the internal diameter of the ring  17  in the region of the toothed rim  16 . The sun gear  14  and disk  15  are preferably formed in one piece, from the same material.  
         [0024]     The disk  15  has, on its underside, a sawtooth formation  21  which runs around the periphery and in which the latching finger  20  of the ring  17  engages as a retaining member (preventing return rotation).  
         [0025]     The sun gear  14  has a coarse toothing formation. Thus, in the exemplary embodiment illustrated, eight sun-gear teeth  22  are distributed uniformly over the circumference of the sun gear  14 . As the sun gear rotates, these teeth  22  interact with the planet gear  13 , which is disposed in the same plane between the sun gear  14  and the toothed rim  16  of the ring  17 .  
         [0026]     The planet gear  13  has an axial pin  23  which projects upward on one side, i.e. in the direction away from the disk  15  of the sun gear  14 . This axial pin is held in a rotatable manner in a bore  24  in the region of a collar  25  of a scale ring  26 , this collar being oriented radially inward in a disk-like manner. The scale ring  26  is provided, on its outer lateral wall, with an encircling graduated scale  27 , the graduated scale corresponding in each case to a number of individual rotary steps of the planet gear  13 , which advances the scale ring  26 . The planet gear additionally meshes with the toothed rim  16  (see  FIG. 2 ), in order to ensure intermediate positions of the scale ring.  
         [0027]     The stepwise displacement of the sun gear  14  and/or of the disk  15 , which is integrally formed therewith, takes place via step-action indexing fingers  28  which can yield resiliently approximately in the vertical direction. These fingers engage on the underside of the sawtooth formation  21  of the disk  15 .  
         [0028]     The step-action indexing fingers  28  are located diametrically opposite one another in relation to the main axis x of the step-action indexing mechanism  11  as a whole. For this purpose, a cylindrical central body in the form of a hub  29  with a central axial through-bore  30  is provided in the first instance. The diameter of this through-bore is slightly larger than the external diameter of the cartridge valve tube  5 , which is to pass through this through-bore  30 .  
         [0029]     At the foot end, the hub  29  merges into a radially widened collar  31 . Radially projecting guide portions  32  are integrally formed diametrically opposite one another on this collar and, in the region of their free ends in each case, form a guide pin  33 , which is positioned in the associated slot  19  of the ring  17 . The hub and fingers  28  are located in the interior of the ring  17  and are set back in relation to the base surface of the housing  34 .  
         [0030]     The step-action indexing fingers  28  each have a horizontal portion rooted on the guide portions  32 , leaving the guide pins  33  to project radially outward beyond the horizontal portion. The step-action indexing fingers  28 , which project from the horizontal portions, extend directed obliquely upward, with the possible inclusion of an angle of 45 degrees in relation to the horizontal, this angle being adapted to the slope of the slots  19  in the ring  17 . The step-action indexing-finger star thus formed is designated S.  
         [0031]     The step-action indexing-finger star S, the ring  17 , which contains the inner toothed rim  16 , the disk  15 , which is integrally formed with the sun gear  14 , and the scale ring  26  are aligned concentrically in relation to one another along the axis x, the height of the ring  17  being selected such that both the step-action indexing-finger star S and the sun gear  14 , together with the disk  15 , are accommodated therein.  
         [0032]     The entire planet-gear mechanism  12  as well as the step-action indexing-finger star S and the scale ring  26  are accommodated in a cup-like step-action indexing-mechanism housing  34  with an external diameter adapted to the external diameter of the cartridge  3 .  
         [0033]     The housing  34  has a lateral wall  35 . The latter has a viewing window  36  through which it is possible to see the graduated scale  27  of the scale ring  26 .  
         [0034]     The housing top  37  contains a central aperture  38  which, in the embodiment which is shown in FIGS.  1  to  3 , is surrounded by resilient latching tongues  39  which taper conically in the direction of the housing interior. The aperture diameter is adapted to a diameter of a narrowed portion  40  of a collar  41  which projects centrally beyond the opening-side end wall of the cartridge  3  at the opening end and from which the valve tube  5  extends.  
         [0035]     The housing base  42  is formed by a separate part. The latter is connected to the housing  34 , for example welded or clipped thereto or secured thereon via a press fit, with the above described individual parts of the step-action indexing mechanism being accommodated therein.  
         [0036]     The plate-like housing base  42  has a central bore for the through-passage of a spike, e.g. of the valve tube  5 . Furthermore, the housing base  42  has formed on it a latching component  44  which, for holding the ring  17  in position, engages in a window-like recess  45  correspondingly formed in the lateral wall  18  of the ring.  
         [0037]     Over the same angle region in which the fitting component  44  is disposed on the base, the outer lateral wall of the housing base  42  has a cutout  46 . In the installed state, this is associated with the region of the outlet cross-section of the flow channel  10  in the lower annular housing part  7 .  
         [0038]     Irrespective of the arrangement which is yet to be described with reference to  FIGS. 3 and 4 , the step-action indexing mechanism  11  basically functions as follows:  
         [0039]     The indexing members (step-action indexing-finger star S, ring  17 , disk  15 , planet gear  13  and scale ring  26 ) as well as the housing  34  with the housing base  42  are disposed along axes which extend in the longitudinal direction of the housing  34 , that is to say of the actuating stroke x-x, in the example also of the cartridge  3 . With the exception of the planet gear  13 , all the rest of the components of the step-action indexing mechanism  11  are in fact positioned along the longitudinal axis x-x of the cartridge.  
         [0040]     The step-action indexing mechanism  11  can be disposed in an extremely straightforward manner correspondingly concentrically within the cross-sectional profile of a component, e.g. the cartridge  3 , specifically in the installation space left between the cartridge head  4  and supporting portion  9  of a standard inhaler  2 . The step-action indexing mechanism  11  is supported on the end surface of the supporting portion  9  of the inhaler housing  2  by way of the hub  29  of the step-action indexing-finger star S, this hub being mounted centrally in the indexing-mechanism housing  34 . The valve tube  5 , which passes through the hub  29 , provides for additional centering of the step-action indexing-mechanism unit as a whole.  
         [0041]     Upon execution of an actuating stroke of the cartridge  3 , and associated vertical displacement of the housing  34  in the direction of a supporting portion  9 , the indexing-mechanism housing  34  is carried along via the cartridge head  4 , this taking place with displacement of the housing  34 , of the planet-gear mechanism  12  and of the scale ring  26  relative to the step-action indexing-finger star S, which is supported on a supporting portion, in this case item  9 . Consequently, the step-action indexing fingers  28 , as they are subjected to stressing, and further assisted by the step-action indexing-finger star S sliding upward with rotary action in the lateral-wall slots  19  of the ring  17 , cause the stepwise rotary advancement of the sawtoothed disk  15 . At the same time, the sun gear  14  rotates by the same angle. The step-action indexing fingers  28  thereby move out of the oblique position in the direction of a plane oriented perpendicularly to the longitudinal axis x-x.  
         [0042]     If the sun gear  14  has, for example, merely eight teeth distributed uniformly over the circumference, it is not necessarily the case that every rotary stepping movement of the sun gear  14  results in a rotary movement of the planet gear  13 . Rather, the rotation of the planet gear  13  about its axis, and the accompanying rotary displacement of the scale ring  26 , takes place only after a number of individual rotary steps of the sun gear  14 . This cumulative function may be more advantageous than 1:1 transmission.  
         [0043]     According to the illustration in  FIG. 3 , in certain cases, the entire step-action indexing mechanism  11  can easily be secured with latching action on a collar  41  by means of the housing  34 . In association with the viewing window  36  of an inhaler, this window being located in the housing, the associated portions of the annular housing parts  6  and  7  then likewise have viewing windows  47 ,  48  which, by virtue of the position selected, directed toward the mouthpiece  8  of the housing  2 , are located within the field of vision of the user operating the hand-held unit  1 . For securing the step-action indexing mechanism  11  in position, this mechanism is provided with a guide blade  49  which projects radially from the housing  34 .  
         [0044]     The step-action indexing mechanism  11  is secured with latching action such that, when the cartridge  3  is removed from the housing  2 , the step-action indexing mechanism  11  is also pulled out, remaining on the cartridge  3  in the process. This is quite possible, even in the medical sector, as a result of the special construction of the step-action indexing mechanism because, once removed, the step-action indexing mechanism cannot, for all practical purposes, be actuated, that is to say it cannot adjust itself.  
         [0045]     As an alternative, it is thus also possible, as is illustrated schematically in  FIG. 4 , for the step-action indexing mechanism  11  to be latched to the housing  2 . For this purpose, during initial assembly, the step-action indexing mechanism  11  passes beyond one or more radially inwardly projecting latching protrusions  51  of the housing  2 , which latching protrusions  51  then have collar portions  52 , which project radially from the indexing-mechanism housing  34 , gripping beneath them. The latching protrusions  51  are positioned, as seen in the vertical direction, so as to ensure the vertical displaceability of the step-action indexing mechanism  11  upon stroke actuation of the cartridge  3 . The arrangement selected results in the latching protrusions  51  forming holding-down means which keep the step-action indexing mechanism  11  in the housing  2  when the cartridge  3  is pulled out. It is then also the case that the indexing mechanism cannot adjust itself.  
         [0046]     A further embodiment (not illustrated) may provide for a combination of the embodiments according to the illustrations in  FIGS. 3 and 4  in which the step-action indexing mechanism  11  is latched on the collar  41  on the cartridge head by means of the resilient latching tongue  39 . Such a preassembled cartridge/step-action indexing-mechanism unit is introduced into the housing  2  of the inhaler prior to initial assembly of the latter, collar portions  52  which project radially on the indexing-mechanism housing  34  passing over latching protrusions  51  on the unit housing in a manner corresponding to the second exemplary embodiment, which results in the step-action indexing mechanism  11  being secured definitively in the housing  2 . This latching between the step-action indexing mechanism  11  and inhaler housing  2  is selected to be more pronounced than the latching between the step-action indexing mechanism  11  and cartridge  3  and accordingly, if the cartridge  3  is pulled out following initial use, the latching between the cartridge  3  and step-action indexing mechanism  11  is released. The re-insertion of the cartridge  3  is facilitated by a relatively weak resilient latching formation for interacting with the collar  41  on the cartridge head.  
         [0047]     Both in the case of the above described embodiment and in the case of the embodiment according to the illustration in  FIG. 4 , it is possible to release the latching between the unit housing  2  and step-action indexing mechanism  11  following removal of the cartridge  3  from the housing  2 .  
         [0048]     The illustration in  FIG. 4   a  shows a further embodiment, which builds on the configuration which is shown in  FIG. 4 . Thus, in order to secure the cartridge  3  further—in addition to conventional clamping of the valve tube  5  in the supporting portion  9  on the hand-held-unit housing—provision is made for the cartridge  3  to be blocked in the region of the upper annular housing part  6 . Obliquely downwardly directed restraining fingers  55  thus project from the inner lateral wall of this upper annular housing part  6  and are formed integrally therewith, from the same material. These restraining fingers  55  are positioned such that their free peripheral edges, positioned in relation to the cartridge  3 , pass with blocking action into that narrowed region of the cartridge  3  which is formed behind the cartridge head  4 , in order to thus block the cartridge  3 . Furthermore, the restraining fingers  55  are formed such that, at least when the housing  2  is initially assembled with the cartridge  3 , the cartridge head  4  can pass over them. It is also the case with this insertion operation, however, that no counting takes place.  
         [0049]     The illustration in  FIG. 5  shows a further embodiment. In this embodiment, the cartridge  3  is also secured on the upper inhaler housing part  6  by means of restraining fingers  55 . This upper inhaler housing part  6  can be released from the lower housing part  7 , which forms the mouthpiece  8 , the two housing parts  6  and  7  being separated approximately in the region where the plate-like step-action indexing-mechanism housing  34  is positioned. When the two housing parts  6  and  7  have been put together, they are preferably latched, for which purpose one housing part has a latching nose and the other housing part has a correspondingly placed latching recess.  
         [0050]     As a result of this separation being possible, the mouthpiece  8 , in particular the angled portion which contains the step portion  9 , is easier to clean. This cleaning is further facilitated in that the entire step-action indexing mechanism  11 , which is in the form of a compact subassembly, can be removed extremely straightforwardly from the lower housing part  7  and thus passed on for separated cleaning without the risk of any counting steps taking place.  
         [0051]     The exemplary embodiment illustrated does not provide any securing means—for example latching protrusions  51  which interact with collar portions  52 . Rather, the step-action indexing mechanism  11  as a whole is secured in the lower housing part  7  in conjunction with the cartridge  3  in the use position, with the step-action indexing mechanism  11  being aligned between the supporting portion  9  and the facing end surface of the cartridge head  4  (as is also illustrated with reference to the embodiment which is shown in  FIG. 4   a ). It is also the case that there is no risk of damage during washing, etc., of the removed step-action indexing mechanism.  
         [0052]     It is also the case in this embodiment that the step-action indexing mechanism  11  is secured against rotary displacement about the axis x-x by a positive connection between the step-action indexing mechanism  11  and lower housing part  7 .  
         [0053]     All features disclosed are (in themselves) pertinent to the invention. The disclosure content of the associated/attached priority documents (copy of the prior application) is hereby also included in full in the disclosure of the application, also for the purpose of incorporating features of these documents in claims of the present application.