Abstract:
An injection device for injecting selectable amounts of a substance includes an activating mechanism including an axially moveable operating button which can rotated in a resting position only, a tubular drive element non-rotatably connected to the operating button, an axially fixed and non-rotatable guiding element, and an axially moveable driven member held non-rotatably in the device. A rotational grid is operationally between rotatable and non-rotatable components of the injection device such that the operating button can be moved two rotational directions when in the resting position whereby a selected amount of the substance to be injected can be selectively varied. For example, a dosage inadvertently selected too large by rotating the operating button too far in one direction can, in accordance with the present invention, be reduced by rotating the operating button in the opposite direction. In some embodiments, the rotational grid is adapted to produce a clicking sound when the operating button is rotated.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S)  
       [0001]     This application is a continuation of International Application No. PCT/CH2003/00532, filed Aug. 7, 2003, which claims priority to German Application No. 10237258.6, filed on Aug. 14, 2002, the contents of which is incorporated in their entirety by reference herein.  
       BACKGROUND  
       [0002]     The present invention relates to devices and methods for administering or delivering substances, including injection devices and methods for making and using them. More particularly, it relates to an injection device for administering an injectable product, in doses, from a product container or ampoule provided with a piston.  
         [0003]     In one embodiment, the injection device comprises a generally tubular activating means which can be driven manually, an operating button on which axial movements and rotational movements can be performed, a drive element which is non-rotatably connected to the operating button and follows the movements of the operating button, and a driven member, operably coupled to the drive element, which can be moved in the advancing direction of the piston, wherein when the operating button is moved axially, the drive element can be shifted in the advancing direction of the piston from a resting position to an end position and back again, this movement transferable onto the driven member.  
         [0004]     An injection device of the type suitable for the present invention is known from EP 0 581 924 B1 (belonging to the Applicant), the disclosure and teachings of which are incorporated herein by reference. The known injection device serves to inject respectively selectable amounts of a liquid product, which preferably contains a medical or therapeutic active agent, from a product container provided with a piston, in particular from an ampoule. The device comprises a tubular activating means which can be driven manually and which comprises an operating button which can be axially and rotationally moved, a drive element which is non-rotatably connected to the operating button and follows the movements of the operating button, a driven member which is non-rotatable with respect to a casing of the device, and a guiding element for the driven member.  
         [0005]     In the known device, a drive element—on which the driven member is movably mounted—can be shifted axially, i.e. in the advancing or dispensing direction of the piston, by a distance predefined by the mechanism, from a resting position to a front end position. The product dosage to be delivered is set by rotating the operating button.  
         [0006]     In one embodiment, a rotational grid is provided between non-rotatable and rotatable parts of the known injection device and comprises two discoid locking elements which oppose each other and each comprise a plurality of locking protrusions and a plurality of locking recesses preferably corresponding to or complementing the locking protrusions, and which co-operate with each other.  
         [0007]     When the dosage to be injected is set by rotating the operating button, the locking protrusions slide off on the locking recesses, producing a sound which is uniquely dependent on the rotational movement of the operating button. In the device of EP 0 581 924 B1, a clicking sound is produced every time the locking protrusions resile into the locking recesses formed to correspond to them. By counting out on the basis of the sound produced, in particular on the basis of the number of clicking sounds, the patient can set the quantity of the new injection dosage purely aurally, i.e., without looking at the device. Setting the dosage to be injected aurally in this way has proven very advantageous, in particular for patients who have developed impaired vision due to an illness, as is, for example, often the case with diabetes patients.  
         [0008]     In the prior art, the rotational grid consists of two disc-shaped locking elements on which serrated locking protrusions or locking recesses, respectively, are arranged at regular intervals in the circumferential direction. The two locking elements are pressed against each other by means of a spring serving as a restoring element, such that the rotational grid and/or operating button can only be rotated in one rotational direction and are blocked in the other rotational direction. This has the disadvantage that a dosage which has been set by rotating the operating button in the first rotational direction can only then be increased further, i.e., by rotating the operating button further in the first direction, but cannot be reduced by rotating the operating button back in the opposite rotational direction. Thus, if the patient has inadvertently selected too large a dosage, for instance because he has incorrectly counted the number of clicking sounds, then the incorrectly selected dosage must first be delivered by advancing the driven member to the front end position. The driven member must then be moved back to the resting position before a new dosage can be set. This procedure is tedious, fraught with error and unnecessarily wastes a lot of product.  
       SUMMARY  
       [0009]     It is an object of the present invention to provide an injection device wherein the dosage to be administered can be simply and reliably pre-set, and wherein it is also possible at any time to reduce a dosage which has once been set.  
         [0010]     In one embodiment, the present invention comprises an injection device for injecting selectable amounts of a substance includes an activating mechanism including an axially moveable operating button which can rotated in a resting position only, a tubular drive element non-rotatably connected to the operating button, an axially fixed and non-rotatable guiding element, and an axially moveable driven member held non-rotatably in the device, wherein a rotational grid is operationally between rotatable and non-rotatable components of the injection device such that the operating button can be moved two rotational directions when in the resting position whereby a selected amount of the substance to be injected can be selectively varied. For example, a dosage inadvertently selected too large by rotating the operating button too far in one direction can, in accordance with the present invention, be reduced by rotating the operating button in the opposite direction. In some embodiments, the rotational grid is adapted to produce a clicking sound when the operating button is rotated.  
         [0011]     The present invention relates to an injection device for injecting respectively selectable amounts of liquid, preferably insulin, from an ampoule. A manual activating means comprises: an operating button which can be axially moved, and rotated in a (rear) resting position only; a tubular drive element which is non-rotatably connected to the operating button; an axially fixed and non-rotatable guiding element; and a driven member which can be axially moved, is held non-rotatably in the device and advances the piston of the ampoule. A rotational grid is provided between rotatable and non-rotatable parts of the injection device and, when the operating button is rotated, produces acoustic sounds, for example clicking sounds, in accordance with the dosage set. In accordance with the invention, the rotational grid is configured such that the operating button can be moved in both rotational directions in its (rear) resting position. A dosage which has inadvertently been selected too large by rotating the operating button too far in a rotational direction can, in accordance with the invention, be reduced again by simply rotating the operating button back in the opposite rotational direction, wherein audible acoustic sounds can also be produced when rotating the operating button back, on the basis of which the patient can determine the set dosage aurally.  
         [0012]     An injection device in accordance with the invention is characterised in that the rotational grid is configured such that the operating button can be moved in both rotational directions in its resting position, i.e., when the driven member is spaced apart from the piston. Because the device in accordance with embodiments of the present invention comprises a rotational grid which emits acoustic sounds—preferably, clicking sounds—when rotated, the patient can also continue to pre-set the dosage audibly or aurally, in particular on the basis of counting the number of clicking sounds. This ensures that dosing is simple and reliable. Because, in accordance with the invention, the rotational grid can be moved in both rotational directions in the resting position, the dosage which has been selected once can also simply be reduced again, without delivering the product unnecessarily, as explained above.  
         [0013]     Preferably, the rotational grid produces the aforesaid acoustic clicking sound not only when the operating button is rotated in the first rotational direction, for example clockwise, but also when the operating button is rotated in the opposite rotational direction, for example anti-clockwise. Thus, the patient can also orientate himself on the basis of the produced acoustic sound and deduce the respectively set dosage when rotating the operating button and/or rotational grid back. The injection device in accordance with the invention can therefore be simply and reliably operated, even without being read.  
         [0014]     In accordance with a preferred embodiment, the operating button and together with it the driven member can only be axially adjusted from the resting position to the front end position when the rotational grid is locked in and the locking protrusions are co-operating substantially completely with the locking recesses formed to correspond to and/or complement them. In this simple way, it is possible to ensure that only a dosage which is set by rotating the operating button by an integer multiple of the circumferential angular intervals of the locking protrusions can be administered.  
         [0015]     In the aforesaid embodiment, a number of locking bodies, for example recesses running in the axial direction and correspondingly formed protrusions running in the axial direction, are preferably formed on the outer circumference of the operating button or on an element arranged non-rotatably with respect to it, wherein the number of locking bodies preferably corresponds to the number of locking protrusions formed on the facing sides of the locking elements of the rotational grid. Only when the locking bodies permit the operating button and the driven member coupled to it to advance axially can the set dosage actually be administered.  
         [0016]     In some preferred embodiments, the aforesaid locking bodies also produce an acoustic sound, in particular clicking sounds, which are preferably produced synchronously with the acoustic sounds, in particular the clicking sounds, of the rotational grid, such that the angular positions of the locking bodies preferably correspond substantially to the angular positions of the locking protrusions and/or recesses of the rotational grid.  
         [0017]     In accordance with a preferred embodiment, a second restoring element is provided which axially retracts an ampoule holder—which forms a first locking element, for example a lower disc, of the rotational grid or is coupled to it—towards the operating button, such that the rotational grid locks in, wherein in the locked-in position of the rotational grid, the locking protrusions co-operate substantially completely with the locking recesses formed to correspond to them, engaging substantially completely with them. The second restorer can, for example, be between the rear part of the injection device, where the activating means which can be manually driven sits, and the ampoule holder.  
         [0018]     In some preferred embodiments, the restoring force of the second restoring element is smaller than that of the first restoring element, such that the rotational grid is not mounted rigidly, but rather sprung, such that the locking elements of the rotational grid, abutted against each other by the restoring elements, elastically resile when the locking protrusions slide off on the locking recesses, which makes the acoustic sound produced even more audible.  
         [0019]     The present invention can be applied to devices of the type described in EP 0 581 924 B1, although it is not in principle restricted to the specific embodiment described in EP 0 581 924 B1. In such an embodiment, a drive element—on which the driven member is movably mounted—can be shifted axially, i.e. in the advancing direction of the piston, by a distance predefined by the mechanism, from a resting position to a front end position. Over a part of the predefined distance, the driven member does not abut the piston of the product container. Over the remaining part of the predefined distance, the driven member abuts the piston stopper, such that when the driven member is advanced further by the remaining part of the predefined distance, the piston is axially advanced, such that a product, such as a medicinal substance or liquid, is delivered from the product container. Once the product has been delivered, the driven member is returned to the resting position with the aid of a restorer. If the driven member were again advanced axially by the distance set for the previous injection, no further product would be delivered from the product container because the driven member is not able to abut the piston.  
         [0020]     In some embodiments, the product is dosed as in the following steps. In its resting position, the operating button can moved rotationally. When the operating button is rotated in the resting position, for example clockwise, the driven member—which is not then abutting the piston—is axially advanced in a controlled way, shortening the interval between the driven member and the piston. The distance by which the interval between the driven member and the piston is shortened when the operating button is rotated corresponds to the distance during which the driven member abuts the piston as it is advanced to the front end position, in order to deliver another product dosage from the product container. The rotational angle by which the operating button is rotated in the first direction, for example clockwise, thus unequivocally defines the product dosage to be delivered.  
         [0021]     In one embodiment, the present invention comprises a method of injecting a selectable amount of a substance, comprising the steps of providing an injection device comprising an activating mechanism comprising an axially moveable operating button which can rotated in a resting position only, a tubular drive element non-rotatably connected to the operating button, an axially fixed and non-rotatable guiding element, an axially moveable driven member held non-rotatably in the device, and a rotational grid operationally between rotatable and non-rotatable components of the injection device such that the operating button can be moved two rotational directions when in the resting position, and rotating the operating button to select an amount of the substance to be injected, wherein if too large an amount is inadvertently selected by rotating the operating button too far in one direction, the too large an amount can be reduced by rotating the operating button in the opposite direction. In some embodiments, the rotational grid is adapted to produce a sound when the operating button is rotated, the method further comprising assessing the amount selected by listening to the sound. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]      FIG. 1  is a longitudinal section through an injection device of the type which is suitable for use in the present invention;  
         [0023]      FIG. 2  schematically shows a rotational grid in a longitudinal section, in accordance with an embodiment of the present invention;  
         [0024]      FIG. 3  schematically shows another embodiment of a rotational grid in accordance with the invention, in a developed view;  
         [0025]      FIG. 4  is a cross-section along line A-A of  FIG. 1 ;  
         [0026]      FIG. 5  is a cross-section along line B-B of the injection device in accordance with  FIG. 1 ;  
         [0027]      FIG. 6  is a cross-section along line C-C of the injection device in accordance with  FIG. 1 ;  
         [0028]      FIG. 7  is shows details of a portion of  FIG. 3 , in an enlargement; and  
         [0029]      FIG. 8 , including  FIGS. 8   a - 8   c,  depicts three different angular positions of an operating button of an injection device in accordance with the invention. 
     
    
     DETAILED DESCRIPTION  
       [0030]     In the figures, identical reference numerals indicate identical or substantially functionally identical elements and functional groups.  
         [0031]     In order to better illustrate the functionality of an injection device in accordance with the invention, an injection device is shown in a longitudinal section in  FIG. 1 . This type of device may be understood by reference to  FIG. 2  of EP 0 581 924 B1, belonging to the Applicant. The present invention is not, however, restricted to this specific embodiment of an injection device.  
         [0032]     Referring then to  FIG. 1 , a front part  2  of the injection device comprises an exchangeable ampoule  4  in which a piston  5  sits such that it can be axially adjusted, said piston  5  delivering the substance stored in the ampoule, which preferably contains a medical or therapeutic active agent, through an injection needle  6 . The rear part  3  of the device has an activating means  7 , designed in the shape of a tube, which can be operated by hand. The activating means  7  comprises an operating button  8 , a driven member formed substantially as a rod  9  with a flange  19 , a guiding element  24  and a drive element  11 .  
         [0033]     As shown in the cross-sections in accordance with  FIGS. 4-6 , the rod  9  has plane surfaces on both sides and otherwise exhibits a circular cross-section which bears a thread. This thread sits in a female thread  27  of the drive element  11 , which sits non-rotatably in the injection device. The drive element  11  can be transferred, together with the entire activating means  7 , from a (rear) resting position to a (front) end position by axially activating the operating button  8  and conveying this movement via the guiding element  24 , against the force of a spring  16  serving as a first restorer. The rod  9  participates in this axial advancing movement, wherein the flange  19  situated on the rod  9  eventually presses against the piston  5  of the ampoule  4 , pushes it forwards and thus effects the injection.  
         [0034]     The rod  9  sits non-rotatably, but can be moved axially, in the guiding element  24 . The guiding element  24  for its part is connected non-rotatably to the operating button  8 . As shown in the cross-section in accordance with  FIG. 4 , the guiding element  24  has an inner contour which (except for any suitable tolerances) is adapted to the outer contour of the rod  9  as described above. The operating button  8 , the guiding element  24  and the rod  9  can only be rotated in the (rear) resting position of the activating means  7 . The rod  9  then rotates in the female thread  27  of the drive element  11  arranged non-rotatably in the injection device, and is this adjusted forwards when the operating button  8  is rotated in a first rotational direction, for example clockwise. As will also be explained below, the operating button in accordance with the prior art cannot be rotated back in the opposite direction—i.e. in the aforesaid case, anti-clockwise—in the state shown in  FIG. 1 .  
         [0035]     As described above, a substance is injected by axially advancing the operating button and the flange  19  serving as the driven member towards the front end position, wherein the operating button and therefore the flange  19  can each be advanced by a unitary, predefined distance only, which is, for example, pre-set by stoppers in the activating means  7  and by the maximum stroke of the operating button  8 . If, after an injection, the operating button  8  is guided back to the (rear) resting position, then no further substance would be delivered from the ampoule  4  if the operating button  8  and the flange  19  were again advanced axially. In order to deliver a subsequent, new dosage, the flange  19  has to be advanced by a distance corresponding to the dosage to be administered, by rotating the operating button  8  in the first rotational direction, such that the distance between the flange  19  serving as the driven member and the piston  5  is shortened by said pre-settable distance. Thus, when the operating button  8  and the flange  19  serving as the driven member are again advanced, the flange  19  abuts the piston  5  at the end of its axial advancing movement and shifts it axially forwards by the distance set by the rotational movement of the operating button  8 , such that a new dosage is delivered from the ampoule  4  which is substantially unequivocally defined by the rotation of the operating button  8 .  
         [0036]     The tubular drive element  11  is connected to the operating button  8 , fixed against rotating. The operating button  8 , which can be axially moved, can only be rotationally moved in its (rear) resting position, and—in accordance with EP 0 581 924 B1—only in one rotational direction, in order to axially advance the flange  19  serving as the driven member. The rod  9 , whose threaded parts on the circular surfaces  13 ,  13 ′ engage with the female thread  27  of the drive element  11 , is held in the interior of the drive element  11 . The rod  9  penetrates through the drive element  11  and the guiding element  24 . The latter is fixedly connected to the rear part  3  of the injection device and can move neither axially nor rotationally. The opening in the guiding element  24 , adapted to the rod  9 , ensures that the rod  9  can only move axially and not rotationally.  
         [0037]     If the operating button  8  is manually advanced axially, it shifts the drive element  11  as far as its (front) end position, which is defined by a stopper  31 , for example a stopper of the drive element  11  on the guiding element  24 . This axial movement is transferred onto the rod  9  sitting in the female thread  27  of the drive element  11 , the rod  9  only being able to move axially and not rotationally.  
         [0038]     The axial movement is performed against the force of a spring  16  which serves as a first restorer and sits in a cavity between the drive element  11  performing the axial movement and a sleeve part  21  of the rotational grid  20  to be described below. The spring  16  urges and moves the activating means  7  back to its resting position again.  
         [0039]     Because the rod  9  is mounted non-rotatably in the guiding element  24 , the rotational movement exerted on the operating button  8  in order to set the next injection dosage cannot be transferred onto the rod  9 . Rather, the rod  9  is non-rotatably driven axially forwards by the rotating female thread  27  of the drive element  11 , via the threaded parts on the circular surfaces  13 ,  13 ′ (cf.  FIG. 4 ), and so moves the flange  19  to the position corresponding to the next injection dosage to be dispensed. When the flange  19  is axially advanced, the distance between the flange  19  and the piston  5  is reduced in accordance with the rotation of the operating button  8 .  
         [0040]     The flange&#39;s  19  path from the (rear) resting position to the (front) end position of the activating means  7  remains constantly the same and corresponds to the constant distance by which the flange  19  is separated from the piston  5  before the injection dosage is set. Thus, by rotating the operating button  8  in the (rear) resting position, the injection dosage to be administered can be set in advance. By rotating the operating button  8  in the first rotational direction in a controlled way, the injection dosage can thus be substantially unequivocally defined.  
         [0041]     In order that the injection dosage can also be reliably set aurally or audibly, on the basis of acoustic sounds, a two-part rotational grid is known from the generic EP 0 581 924 B1 which only permits the operating button  8  to rotate in the first rotational direction, for example clockwise, and blocks it from rotating in the second, opposite rotational direction, for example anti-clockwise. When the rotational grid is rotated, locking protrusions slide off on locking recesses, such that a defined acoustic sound, e.g. a clicking sound, is produced in unique correlation with the rotational movement of the operating button  8 .  
         [0042]     The rotational grid  20  sits generally between the non-rotatable and rotatable parts of the injection device. The rotational grid  20  is schematically shown in  FIG. 7 . In accordance with EP 0 581 924 B1, the rotational grid  20  comprises two locking elements  21 ,  22  which abut each other in the aforesaid resting position and comprise a plurality of serrated locking protrusions, and/or locking recesses formed to correspond to the protrusions, running in the circumferential direction and preferably arranged at regular angular intervals, as shown in  FIG. 7 . The locking element  22  corresponds to the ampoule holder  29  or is mechanically coupled to it. The locking element  21  corresponds to a sleeve part of the tubular drive element  11  which is rotatably mounted and non-rotatably connected to the operating button  8 .  
         [0043]     When the two locking elements  21 ,  22  are rotated relative to each other, the serrated locking protrusions slide off on the correspondingly formed and/or complementary locking recesses. Because the two locking elements  21 ,  22  are pressed against each other by means of the restoring force of the spring  16  serving as a first restorer, the two locking elements  21 ,  22  resile after completely sliding off a serrated locking protrusion, which produces a clearly audible clicking sound which serves as an acoustic sound for setting the injection dosage “aurally”. The rotational grid in accordance with EP 0 581 924 B1—and, correspondingly, as set forth in WO 87/02895—can only be moved rotationally in one rotational direction. Thus, if the operating button  8  is rotated too far in the first rotational direction, for instance because a user has incorrectly counted the number of clocking sounds, then the operating button  8  cannot be rotated back. The incorrectly set injection dosage cannot therefore be reduced again. Rather, the substance has to be unnecessarily delivered by axially advancing the operating button  8  and a new injection dosage cannot be reset until the operating button  8  has returned to the (rear) resting position.  
         [0044]     In accordance with the present invention, the rotational grid  20  comprises more than two locking elements which can be rotated relative to each other, in some embodiments, three locking elements which can be rotated relative to each other.  FIGS. 2 and 3  schematically show two exemplary embodiments of the present invention.  
         [0045]      FIG. 2  shows a partial longitudinal section of a first exemplary embodiment in which the rotational grid  20  comprises a lower sliding sleeve  36 , a sagittal ring  37  comprising locking protrusions  41  and serving as an intermediate disc and an upper sliding sleeve  38 . The upper sliding sleeve  38  is non-rotatably connected to the operating button  8  (not shown in  FIG. 2 ), for example via the schematically shown cylindrical intermediate piece  42 . The lower sliding sleeve  36  is preferably connected to the ampoule holder  29 , for example via the schematically shown cylindrical intermediate piece  43 .  
         [0046]     The disc-shaped sliding sleeves  36 ,  38  serving as locking elements and the sagittal ring  37  comprise a plurality of locking protrusions  31  and locking recesses formed to correspond to and/or complement the protrusions.  
         [0047]     If the upper sliding sleeve  38  is rotated to the left, then the locking recesses formed in it slide off on the locking protrusions  41 , resulting in their being axially retracted against the restoring force of the spring  16 . If the upper sliding sleeve  38  is rotated further to the left, the locking recess eventually engages with the next locking protrusion  41 . Due to the restoring force of the spring  16 , the upper sliding sleeve  38  resiles and thereby produces an audible clicking sound. Due to the corresponding PF separation of the locking protrusions  41  on the sagittal ring  37 , it is blocked to the left when the upper sliding sleeve  38  is rotated, thus remaining in the locking recesses formed on the facing side of the upper sliding sleeve  38 .  
         [0048]     If, by contrast, the operating button  8  (not shown) is rotated to the right in  FIG. 2 , i.e. in the opposite rotational direction, then the locking protrusions  41  on the upper facing side of the sagittal ring  37  and the locking recesses formed on the facing side of the upper sliding sleeve  38  remain hooked to each other, and the locking recesses formed on the lower facing side of the sagittal ring  37  slide off on the locking protrusions formed on the upper facing side of the lower sliding sleeve  36 . This axially retracts the sagittal ring  37  and the upper sliding sleeve  38 , against the restoring force of the spring  16 . If the operating button  8  is rotated further to the right, the locking protrusions formed on the lower facing side of the sagittal ring  37  eventually engage with the next locking recess on the upper facing side of the lower sliding sleeve  36 , wherein the upper sliding sleeves  38  and the sagittal ring  37  resile due to the restoring force of the spring  16 , producing a clearly perceptible clicking sound.  
         [0049]     In accordance with the invention, therefore, clicking sounds or suitable, generally comparable acoustic sounds are produced when the operating button  8  is rotated both clockwise and anti-clockwise. The patient thus only has to note in which direction he or she is turning the operating button  8  and can thus deduce or assess the set or selected injection dosage from the number of clicking sounds. If an inadvertently too large an injection dosage has been set by rotating the operating button  8  in the first rotational direction, for example clockwise, then in accordance with the invention, the user can rotate the operating button  8  in the opposite rotational direction, i.e. in reverse, for example, anti-clockwise, and reduce the injection dosage again. Clicking sounds or comparable acoustic sounds are also produced when the operating button  8  is rotated back, from which the user can deduce the injection dosage.  
         [0050]     In the exemplary embodiment in accordance with  FIG. 2 , the locking protrusions  41  provided on mutually opposing facing sides of the sagittal ring  37  serving as the intermediate disc are arranged—as viewed in the advancing direction of the piston  5 —at mutually flush angular positions.  
         [0051]      FIG. 3  shows another exemplary embodiment in accordance with the present invention, in which locking protrusions on an upper and lower disc, each serving as a locking element, are arranged—as viewed in the advancing direction of the piston  5 —at angular positions offset with respect to each other, in the resting position of the operating button  8 . In accordance with  FIG. 3 , the rotational grid  20  comprises an upper disc  21 , a lower disc  22  and an intermediate disc  23 . The upper disc  21  and the lower disc  22  comprise a plurality of serrated locking protrusions  41 , in some preferred embodiments, arranged at regular angular intervals. Corresponding to or complementing these, the intermediate disc  23  also comprises locking protrusions and locking recesses. The upper disc  21  pressed towards the lower disc  22  by the restoring force of a spring  16  (not shown in  FIG. 3 ) serving as a first restorer. In the resting position of the operating button  8 , the locking protrusions  41  preferably engage substantially completely with the locking recesses formed to correspond to them.  
         [0052]     When the upper disc  21  is rotated relative to the lower disc  22 , the result is the progression of movement shown schematically in the views in accordance with  FIG. 8 , including  FIGS. 8   a - 8   c.    FIG. 8   a  shows the initial state of the rotational grid  20  in the resting position of the operating button  8  (not shown), in which the overall height of the rotational grid  20  is at a minimum. When the upper disc  21 —which is non-rotatably connected to the operating button  8  (not shown in this Figure)—is rotated to the left, the locking protrusions formed on the upper facing side of the intermediate disc  23  remain hooked to the locking recesses formed on the lower facing side of the upper disc  21 , such that the locking protrusions formed on the lower facing side of the intermediate disc  23  slide off on the locking recesses, formed to correspond to them, on the upper facing side of the lower disc  22 . When rotated further, the locking protrusions formed on the lower facing side of the intermediate disc  23  eventually reach the next locking protrusions. Due to a restoring force, the discs  21 ,  22 ,  23  are then pressed onto each other, such that the initial position of the rotational grid  20  shown in  FIG. 8   a  is again assumed. When the upper disc  21  and intermediate disc  23  resile, a perceptible clicking sound is produced.  
         [0053]     When the upper disc  21  is rotated in the opposite rotational direction, i.e. to the right in  FIG. 8   c,  the result is a corresponding progression of movement which can be directly gathered from  FIG. 8   c.    
         [0054]     The various locking elements of the rotational grid  20 , i.e. the discs  36  to  38  in the exemplary embodiment in accordance with  FIG. 2  and the discs  21  to  23  of the second exemplary embodiment in accordance with  FIG. 3 , respectively, are reset and abutted against each other with the aid of two restorers, preferably springs, as follows. As shown in  FIG. 1 , the front part  2  is connected to the rear part  3  of the injection device via the coarse thread  30 . While the tubular drive element  11  sits in the rear part  3 , the ampoule  4  sits in the front part  2  of the injection device. An ampoule holder  29 , which is, in some embodiments, in the shape of a hollow cylinder and through which the flange  19  serving as the driven member penetrates, lies on the upper facing edge of the ampoule  4 . In order to elastically mount the ampoule  4  in the front part  2  of the injection device, a spring  35  serving as the second restorer sits between the ampoule holder  29  and the rear part  3 . If the ampoule  4  is sitting loosely on the ampoule holder  29 , for instance because the front part  2  is not yet completely screwed onto the coarse thread  30 , then the second spring  35  pushes the ampoule  4  and the ampoule holder  29  axially forwards. Because one side of the rotational grid  20  in accordance with the invention, for example the lower disc  36  in  FIG. 2  or the lower disc  22  in  FIG. 3 , is coupled to or formed by the ampoule holder  29 , the rotational grid  20  thus disengages. In this position, the operating button  8  can be rotated back without locking resistances, for example in order to fully return the flange  19  and the rod  9  to an initial position when a new ampoule  4  is to be inserted, the piston  5  of which is initially in the rearmost end position.  
         [0055]     The length of the ampoule  4  and the length of a receptacle serving to store the ampoule  4  in the front part  2  are adjusted to each other, such that when the front part  2  is completely screwed onto the coarse thread  30 , the rotational grid in accordance with the invention fully locks in, i.e. assumes an initial position in which the complementary locking protrusions and locking recesses engage substantially completely and full-face with each other, as shown for example in  FIG. 2 ,  FIG. 3  and  FIG. 8   a.    
         [0056]     In this initial position, the second spring  35  is preferably not fully compressed, such that when the rotational grid  20  in accordance with the invention is rotated, the progressions of movement of the locking elements of the rotational grid  20 —described above on the basis of  FIGS. 2, 3  and  8 —can be performed, in order to produce acoustic sounds, preferably clicking sounds.  
         [0057]     The operating button  8  for delivering the dosage set can preferably only be axially shifted from the (rear) resting position to the (front) end position when the rotational grid  20  is locked in, i.e. when it assumes the initial position shown in  FIG. 2  and in  FIGS. 3 and 8   a,  respectively, in which the locking protrusions and the locking recesses engage substantially completely and full-face with each other. This measure ensures that the dosings which may be administered cannot be set across a continuum, but only in integer multiples of minimum dosages which are substantially unequivocally pre-set by the angular distance of the locking protrusions of the rotational grid  20 . This simultaneously ensures that when the rotational grid  20  is rotated by one locking protrusion, corresponding to increasing or reducing the dosage set by a minimum dosage, a clicking sound or comparable acoustic sound is produced. In accordance with this preferred embodiment, the operating button  8  can only be axially shifted when—after the aforesaid resiling and the clicking sound thus produced—the rotational grid  20  again assumes the initial position shown in  FIGS. 2, 3  and  8   a,  respectively.  
         [0058]     For this purpose, a number of locking bodies can be arranged on the outer circumference of the operating button  8  or on an element—for example, a guiding sleeve—arranged non-rotatably with respect to it, wherein the number of locking bodies corresponds to the number of locking protrusions on the facing sides of the locking elements  21 - 23  and  36 - 38 , respectively, of the rotational grid  20  in accordance with the invention. As shown schematically in  FIG. 6 , which is a cross-section along line C-C in  FIG. 1 , the operating button  8  bears four locking bodies  14  on its outer circumference in this example, which are arranged at equal angular intervals, i.e. at 90°, and are formed as axially running protrusions, wherein  FIG. 6  is based on the non-restricting assumption that the rotational grid respectively comprises four locking protrusions and/or locking recesses on the facing sides of the locking elements. In their angular position with respect to the locking protrusions and/or locking recesses on the respective facing sides of the rotational grid  20  in accordance with the invention, the locking bodies  14  can be arranged flush or offset. Only when an axial groove, formed in the ring surrounding the operating button  8  to correspond to the locking body  14 , is flush can the operating button  8  be axially shifted. This angular position is preferably co-ordinated with the angular position in which the rotational grid  20  is locked in.  
         [0059]     In the injection device-shown in  FIG. 1 , the fixed guiding element  24  lies in front of the tubular drive element  11 . The drive element  11 , installed non-rotatably in the injection device  1 , can of course also be arranged in front of the guiding element  24  in accordance with the present invention, said arrangement being known, for example, from WO 87/02895. Instead of the cylindrical ampoule  4  shown in the figures, a different vessel comprising a piston  5  can also be used as the product container.  
         [0060]     While a specific embodiment has been described above, similar to the injection device known from EP 0 581 924 B1 belonging to the Applicant, the present invention is not in principle restricted to this specific embodiment. Rather, the present invention can in principle be applied to comparable injection devices in which a rotational grid or comparable latching block is provided between non-rotatable and rotatable parts of the device. An example of another such embodiment is known from WO 97/17096 belonging to the Applicant. This document is expressly to be incorporated by the present application by way of reference. In an injection device comparable to WO 97/17096, the dosage is set by rotating an operating button. When the operating button is rotated, a threaded nut is shifted along a thread, altering the distance between the threaded nut and the piston of the ampoule. When the operating button is axially activated, the threaded rod and the piston are axially adjusted by the distance pre-set in this way, in order to deliver the product in doses.  
         [0061]     The injection device in accordance with the invention may be preferably used in auto-therapy by diabetes patients in which they self-administer insulin doses prescribed by their doctor. For this purpose, in some embodiments, the injection device preferably comprises a 30-gauge or 31-gauge injection needle  6 .  
         [0062]     In the foregoing description, preferred embodiments of the invention have been presented for the purpose of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms or steps disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments were chosen and described to provide the best illustration of the principles of the invention and its practical application, and to enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth they are fairly, legally, and equitably entitled.