HK1071318B - Reservoir module with a piston rod - Google Patents

Description

Storage module comprising a piston rod

The present invention relates to a reservoir module fitted with a piston rod, and a product dispensing device comprising such a reservoir module. In a preferred embodiment, the product dispensing device is an administration device, such as an injection device or an inhalation device for medical, therapeutic, diagnostic, pharmaceutical or cosmetic use. A preferred injection device is an injection pen, in particular a semi-disposable injection pen.

WO97/17095 discloses an injection device comprising a dosing and actuating module and a storage module detachably connected to each other. The storage module is designed as a disposable module, while the dosing and actuating module can be reused with a new storage module after the storage module has been used. The reservoir module comprises a reservoir for the product to be injected and is fitted with a piston rod which acts on a piston contained in the reservoir to deliver the product. The piston rod has an external thread which is in threaded engagement with an internal thread of a dose setting member. The piston rod is guided linearly such that when the dose setting member is rotated, the piston rod is moved towards the piston, thereby changing the micro distance between the front end of the piston rod and the piston. The reservoir module is also fitted with a dose setting member and thus also comprises a piston rod and a dose setting member which are discarded together with the reservoir as a single module after the reservoir has been emptied.

One advantage of the structure of the semi-disposable injection device is that the components of the injection device involved in dosing and delivery need only be configured for delivering the contents of a single reservoir. This reduces the price of these components. Since these components must always be guided back to the initial position by the user after repeated use. They are further exposed to the risk of damage, which cannot be underestimated. Thus for a semi-disposable injection device the reliability of correct selection and delivery of the dose must not be lower than for a fully reusable device. In addition, replacing the entire storage module is simpler than replacing only one storage.

The dose setting member of the known device is pushed into a rear position for dosing the product by a compression spring supported by the housing of the reservoir module. By dosing the product, the piston rod is advanced towards the piston relative to the dose setting member and the housing of the storage module. The product is dispensed through a dosing and actuating means which is mounted in the housing of the dosing and actuating module and pushes against the rear abutment area of the dose setting member. The dosing and actuating means pushes the dose setting member in the forward direction and due to the screw thread fit also the piston rod together with it.

It is an object of the present invention to further reduce the price of a product dispensing device, in particular an injection device using a reservoir module as a piston rod mount, while at the same time maintaining reliability in terms of correct selection and delivery of product doses.

The invention relates to a product dispensing device, in particular an injection device, comprising a storage module and a dosing and actuating module which are detachably connected to one another. The above-described product dispensing device is preferably already formed from only these two modules. The reservoir module comprises a front housing part of the above-mentioned product dispensing device, comprising a reservoir for a product to be dispensed, which is preferably fluid, particularly preferably injectable, and a first connecting element. A piston is received in the reservoir so that product can be dispensed from the reservoir by moving the piston in an advancing direction. The reservoir module further includes a piston rod retained by the front housing portion. Finally, the reservoir module may comprise an injection needle or, for example, a nozzle for needle-free injection.

The reservoir may be constituted by a container accommodated in the housing. In particular an ampoule, may for example form the reservoir. In principle, however, the reservoir can also be formed directly from the housing itself, i.e. without the insertion of a product container. The product is preferably a liquid for medical, therapeutic, diagnostic, pharmaceutical or cosmetic use. The product may be, for example, insulin or growth hormone. The product dispensing device is preferably an injection device, preferably for applications where the user dispenses the product himself/herself, as is common in diabetes treatment. But does not preclude use by trained personnel in the field of hospitalization or outpatient service. In other applications where it is necessary or only necessary to dose the product, the product may also be a paste, for example.

It is also understood that the piston rod may be fixedly, i.e. permanently, connected to the piston, so that the piston and the piston rod are made in one piece. In a preferred embodiment, however, the piston and piston rod are made as separate components, the forward end of the piston rod pushing against the rear side of the piston for dispensing product.

The dosing and actuating module comprises a rear housing part of the product dispensing device, which rear housing part comprises a second connecting means which, together with the first connecting means, forms a detachable connection between the reservoir module and the dosing and actuating module. The front housing part and the rear housing part preferably form the entire housing of the device. The first and second connecting means can preferably form a rotary connection, in particular a screw connection, for example. More preferably, however, the two housing parts are slid linearly onto each other, wherein the first and second coupling means form a linear guide preventing the two housing parts from rotating relative to each other. In addition, they preferably together form a latching device, so that the regions of the housing parts which slide onto one another cannot simply be pulled apart again.

The dosing and actuating module further comprises a dosing and driving device, by means of which a dosing movement for selecting a product dose and a dispensing movement for dispensing a product dose can be carried out relative to the connected housing part.

If the connecting device forms a blocking device, the blocking device preferably comprises a blocking block which only allows the two housing parts to be blocked onto one another in the front position of the actuating element or of the dosing and actuating element of the dosing and actuating device.

Finally, the product dispensing device comprises a dose setting member which is moved in an advancing direction by the dosing and drive means during said dispensing movement and cooperates with each piston rod and at least one housing part such that it can only be moved in the advancing direction together with the piston rod and relative to the piston rod opposite to the advancing direction by the dosing movement of the dosing and drive means. The fit with the piston rod is preferably a threaded fit. In principle, however, the fit may also be formed differently, for example forming a toothed fit allowing the dose setting member to move opposite to the advancing direction but preventing the dose setting member from moving in the advancing direction relative to the piston rod. Although the dose setting element may in principle be a component of the dosing and actuation module, it is preferably a component of the reservoir module, i.e. it is preferably already held on the reservoir module before the reservoir module is connected with the dosing and actuation module.

According to the invention, the front housing part comprises a blocking means and the piston rod comprises a return blocking means which are in blocking engagement with each other, said blocking engagement allowing the piston rod to move in the forward direction relative to the front housing part but preventing movement opposite to the forward direction. As a desired side effect, the blocking fit itself may ensure that the piston rod does not move in the forward direction relative to the front housing part when a product dose is selected. If the piston rod has not been sufficiently firmly fixed by the blocking fit itself for this purpose, the blocking means further comprise a braking means for preventing the piston rod from moving in the forward direction when selecting a product dose by applying an additional frictional force.

In the product dispensing device of the invention, the pressure spring is omitted, as compared to the device of WO97/17095, which in the known device ensures that the piston rod and the dose setting member are in their final position during dosing. The saving of parts at the same time means a cost saving. This increases the saving effect since a reduced number of components are present on one side of the storage module. Since the storage module according to the invention is preferably designed as a disposable module, the saving effect is felt each time such a storage module is replaced.

If the dose setting member participates in the dosing movement of the dosing and drive means, it preferably ensures that: when the coupling necessary for this is established between the dosing and driving means and the dose setting member by connecting the two modules, no dosing movement of the dose setting member occurs. For this purpose, when the module is connected, the dose setting member and the dosing member, or a combined dosing and driving member of a dosing and driving device to which the dose setting member is coupled, are held in a preset position relative to each other with respect to the dosing movement. If the dosing movement is a rotational movement around an axis pointing in the direction of the dispensing movement, the dose setting member and the dosing member or the dosing and driving member are held in a preset rotational angular position relative to each other when the module is connected. The use of a linear guide of the housing parts advantageously ensures that establishing the connection does not result in a dosing movement of the dose setting member if the dose setting member and the dosing member or the dosing and driving member are held in a preset rotational angular position by the front housing part and the rear housing part, respectively. If the housing parts perform a rotational movement relative to each other when the module is connected, the dosing movement of the dose setting member is prevented in another way.

The product dispensing device may comprise a stop which ensures that the reservoir module can only be disengaged from the dosing and actuating module in the forwardmost position of the piston rod. In order to reliably prevent the reservoir module from being used again, the piston rod must in this case be held in its foremost position, so that the user cannot transfer it back to an axial position in which the product can be dispensed again with the same piston rod once the reservoir has been replaced. Preferably however, the blocking cooperation between the return blocking means formed on the piston rod and the blocking means of the front housing part retains the piston rod after each dose of product has been dispensed, thereby preventing its transfer to an earlier axial position. If it is further ensured that the piston rod and the reservoir cannot be separated from each other, the reservoir is advantageously prevented from being replaced in the entire axial position of the piston rod. The blocking fit also simultaneously forms a tight fit at any axial position of the piston rod.

In a preferred exemplary embodiment, the return blocking means are constituted by saw-tooth-shaped teeth which project from the piston rod and form a row of teeth with preferably regular intervals. The present inventors have recognized that the principle of a toothed rack, known per se for quantification, can be advantageously applied to a storage module designed as a disposable module, thereby reducing the cost of the storage module, and as a result, in particular, also the cost of the product dispensing system as a whole. Including a tapered tooth in the forward direction and a series of serrated teeth in the rear stop region, while also providing a secure fit as a by-product of each stop fit that prevents the piston rod from returning.

The tight fit between the blocking means preventing the return of the piston rod and the piston rod is not releasable. In this context, non-releasable means that the user cannot release it without destroying it. It should be excluded from the outset that the storage module can be reworked to a closed loop, in which case the blocking fit can be released, for example, by the manufacturer with a special tool. But it is ensured that a user using the product dispensing device to self-administer a medicament, for example to dispense insulin or growth hormone, cannot replace or refill the reservoir.

The dosing and driving means may be operated manually, semi-automatically or fully automatically. In the first case, both the rotary dosing movement and the translatory dosing movement are done manually. In the second case, one of the rotary dosing movement and the translational dosing movement is done manually, the other movement being done with a motor or by applying another type of force, for example by spring force, when the user starts the corresponding movement with the actuating handle. In the third case, i.e. in the case of a fully automatic dosing and driving device, both the dosing movement and the dispensing movement are performed by a motor or by another force, such as an elastic force. In this case, the dose is only manually selected, for example by means of one or more push-buttons, and the sending movement is similarly initiated by the user by means of its own corresponding actuating handle. In most embodiments the drug delivery device of the present invention is provided with a manual dosing and driving means, in this case referred to as dosing and actuating means. So far as the dosing and actuating means are concerned, this is referred to as a manual embodiment. When referring to dosing and driving means, the invention is not intended to be limited to manual, semi-automatic or fully automatic, but includes each of these embodiments. The term dosing and actuating module is used in connection with all embodiments of the dosing and driving means.

The dosing and driving means may comprise separately a dosing member for performing the dosing movement and a driving member for performing the dispensing movement. Preferably, however, the dosing movement and the sending movement are performed by the same dosing and driving device body, and are therefore referred to below as dosing and driving elements or dosing and actuating elements.

The product is preferably a fluid, particularly preferably a liquid having medical, therapeutic, diagnostic, pharmaceutical or cosmetic use. The product may be, for example, insulin, growth hormone or a thick or thin paste. The administration device is preferably applied for applications in which the product is administered by the user himself, as is common in the treatment of diabetes. But does not preclude use by trained personnel in the field of hospitalization or outpatient service.

In the case of an injection device, the product may be dispensed through an injection cannula or nozzle, such as a needle-free injection. The product can be administered by subcutaneous or intravenous or intramuscular injection or infusion. When administered by inhalation, a selected dose of product may be delivered from the reservoir into a chamber of the inhalation device, for example, and inhaled by vaporisation means. In addition, a few examples of administration contemplate oral swallowing, or administration through the esophagus.

The administration device is particularly preferably semi-disposable. In this case, the front housing part is the support for the reservoir module which is discarded or recycled after the reservoir has been emptied, and the rear housing part is the support for the dosing and actuating module which can be reused in combination with a new reservoir module. Since the storage module can also be handled separately as a disposable module, it can also be a separate subject of the invention. The dosing and actuating module may also be an independent subject of the invention. Likewise, a system comprising a dosing device and at least one storage module which can replace the storage module of the device after use also forms a subject of the present invention. This dual design of the administration device, divided into a portion for single use only and a portion provided for re-use (semi-disposable type), is particularly advantageous for injection pens, but also for inhalation devices or oral swallowing products or manually supplied inhalation devices.

Further preferred embodiments of the invention are described in the dependent claims, wherein features directed only to the administration device or only to the reservoir module or the dosing and actuating module, respectively, are likewise preferred features for the further subject matter of the claims.

Example embodiments of the invention will now be described on the basis of the accompanying drawings. The features disclosed in the exemplary embodiments may be used to advantage, individually or in any combination of these features, to develop the subject matter of the claims. Even features disclosed by one example only, respectively develop other examples or show an alternative, given that the contrary is not disclosed or that only this is possible. Shown here are:

FIG. 1 shows two portions of a storage module according to a first exemplary embodiment;

FIG. 2 shows a storage module obtained from two parts in FIG. 1;

fig. 3 an injection device comprising the storage module of fig. 2 in longitudinal section according to a first exemplary embodiment;

FIG. 4 is a portion of the injection apparatus of FIG. 3;

fig. 5a mechanism holder of a storage module in longitudinal section and in two views;

FIG. 6 a blocking device for the piston rod mounted by the mechanism holder;

figure 7 the piston rod in longitudinal section and in front view;

figure 8 shows the locking block in a longitudinal section, a view and a top view;

fig. 9a second exemplary embodiment of an injection device;

FIG. 10 is a cross-section A-A of FIG. 9;

FIG. 11 is a cross-section B-B of FIG. 9;

FIG. 12 is a section C-C in FIG. 9;

FIG. 13 is a cross-section D-D of FIG. 9;

FIG. 14 illustrates, in perspective view, a mechanism retainer of the second exemplary embodiment;

FIG. 15 shows the mechanism retainer of FIG. 14 in a view;

FIG. 16 is a cross-section A-A of FIG. 15;

fig. 17 shows in perspective a dose setting member of the second exemplary embodiment;

fig. 18 shows the dose setting member of fig. 17 in longitudinal section;

FIG. 19 shows the dose setting member of FIG. 17 in a view;

fig. 20 shows the dose setting member of fig. 17 in a top view;

fig. 21 is a part of the injection device according to fig. 3; and

fig. 22 a part of the injection device according to fig. 9.

Fig. 1 shows a storage component 1 and a mechanism holder 3, which are connected to one another to form the storage module 10 shown in fig. 2.

In addition, fig. 1 and 2 show a piston rod which projects into the mechanism holder 3 at the end of the mechanism holder 3 facing away from the storage component 1 and is mounted by the mechanism holder 3 so as to be displaceable in the longitudinal axis L of the piston rod 4 in the direction of advance of the front end of the storage component 1 facing away from the mechanism holder 3. The storage part 1 is essentially a hollow cylinder with a circular cross-section and comprises at its front end a connection area for connection with a needle holder of an injection needle. The storage part 1 serves to accommodate a storage container which in the exemplary embodiment is formed by an ampoule, the longitudinal section of which can be seen in fig. 3. The outlet at the front end of ampoule 2 is fluid-tightly sealed by a membrane. When the needle holder is fastened to the front end of the storage part 1, the rear part of the injection needle pierces the membrane, thereby establishing a fluid connection between the end of the hollow injection needle and the reservoir 2.

Fig. 3 shows the injection device in its entirety in longitudinal section. A piston is housed in ampoule 2 so as to be displaceable in an advancing direction towards an outlet formed at the front end of ampoule 2. Displacing the piston in the forward direction moves the product out of ampoule 2 and through the outlet and the injection needle.

The piston is pushed by the piston rod 4, and the piston rod 4 pushes against the piston through its front end, thereby moving the piston in the advancing direction when advancing itself. The piston rod 4 is held by the mechanism holder 3 so that it can move in the advancing direction, but not opposite to the advancing direction, once a certain resistance is overcome. The piston rod 4 is prevented from moving backwards opposite to the forward direction by a blocking device 8. The blocking device 8 is axially fixed by the mechanism holder 3, i.e. it is held in the mechanism holder 3 so that it cannot move in and opposite to the advancing direction. But it is mounted by the mechanism holder 3 so that it can rotate about the longitudinal axis L. The blocking means 8 also create a resistance which must be overcome for the forward movement.

Only the blocking means 8 are shown in fig. 6. The blocking means 8 are constituted by a one-piece annular element rotatable about the longitudinal axis L, which is pressed against the mechanism holder 3 between two facing, spaced-apart collars 3b, which collars 3b protrude radially inwards from the inner surface of the mechanism holder 3. The collar 3b forms a fixing means for axially fixing the blocking means 8. From the illustration of the mechanism holder 3 in fig. 5, it can be seen most clearly how the blocking means 8 are mounted in the mechanism holder 3.

In addition, a dose setting member 9 is accommodated in the mechanism holder 3. The dose setting member 9 is made as a threaded nut and is in threaded engagement with the outer thread of the piston rod 4. The dose setting member 9 is secured against rotation by the mechanism holder 3, but is guided to be axially and linearly movable in and opposite to the advancing direction. The piston rod 4 and the dose setting member 9 form a spindle drive for selecting a dose of product to be dispensed.

The ampoule holder 1 and the mechanism holder 3 are interconnected, secured against rotation and displacement, together forming a reservoir module 10 of the injection device, said reservoir module 10 comprising a piston rod 4 and a dose setting element 9 held by the mechanism holder 3 via blocking means 8. The ampoule holder 1 and the mechanism holder 3 together form a front housing part of the injection device. The rear housing part 11 is connected in any locking relationship with the front housing parts 1, 3 described above. The rear housing part 11 forms a support for the dosing and actuating element 12 and, together with the dosing and actuating element 12 and the parts of the locking mechanism and other parts, forms a dosing and actuating module 30 of the injection device.

In addition to the dose setting element 9, the piston rod 4 and the blocking means 8, the dosing and actuating module comprises further components for selecting a dose of product and actuating the injection means. In particular, it comprises a dosing and actuating element 12. The dosing and actuating means further comprise a counting and indicating means 17 for counting and optionally indicating the selected product dose. In particular the counting and indicating means 17 make the dosing and actuating module 30 a high-grade and therefore expensive component of the injection device. Although the less expensive storage module 10 is designed as a disposable module, the dosing and actuation module 30 can be reused, always with new storage modules 10.

For selecting a product dose, i.e. for dosing, the dosing and actuating element 12 is rotatable about the longitudinal axis L and is further mounted by the rear housing part 11 such that it can be displaced linearly along the longitudinal axis L in and opposite to the advancing direction. The dosing and actuating element 12 is hollow and cylindrical and surrounds the piston rod 4 through the front. The rear part of the dosing and actuating element 12 protrudes outwards beyond the rear end of the housing part 11. A rod-shaped dosing follower 13 is inserted into the dosing and actuating element 12 from the rear until the dosing and actuating element 12 has a collar projecting radially inwards. In addition, at the rear end, a closure 14 is inserted into the dosing and actuating element 12 up to the dosing follower 13. The dosing follower 13 is axially fixed relative to the dosing and actuating element 12 between a radially projecting collar of the dosing and actuating element 12 and the closure 14. The dosing follower 13 is also fast and non-rotatably connected with the dosing and actuating element 12. For dosing, the dosing follower 13 projects from the rear into the hollow piston rod 4. The piston rod 4 comprises a connecting portion 4a (fig. 4), which connecting portion 4a cooperates with the dosing follower 13 such that the piston rod 4 and the dosing follower 13, and thus the dosing and actuating element 12, cannot rotate relative to each other around a common longitudinal axis L, but can move relative to each other in and opposite to the advance direction along the longitudinal axis L. For this purpose, the connecting portion 4a is made as a linear guide for the dosing follower 13.

A return device 16 elastically tensions the dosing and actuating element 12, counter to the advancing direction, to the initial position shown in figures 3 and 4. In this initial position, the product can be dosed by rotating the dosing and actuating element 12 about the longitudinal axis L. The selected product dose can then be delivered from the initial position by axially displacing the dosing and actuating element 12. The return means 16 are made of a helical spring acting as a pressure spring, which is accommodated in an annular gap surrounding the dosing and actuating element 12 and is axially supported between a collar of the housing part 11 projecting radially inwards and a facing and radially outwards projecting collar of the dosing and actuating element 12.

The blocking means 8 may fulfil a dual function. On the one hand, it ensures by way of its blocking element 8a that the piston rod 4 cannot be moved back counter to the advancing direction relative to the mechanism holder 3 and thus in particular relative to the piston accommodated in the ampoule 2. In its dual function as a brake, the blocking means 8 also prevents the piston rod 4 from moving forward during dosing, during which the dose setting member 9 is moved axially towards the dosing and actuating member 12 opposite to the advancing direction.

In the initial position shown in fig. 3 and 4, the dose setting member 9 is pressed in the advancing direction against one of the delivery stops 3c (fig. 5) formed by the mechanism holder 3 before dosing. The piston rod 4 is in permanent touch contact with the piston. For dosing, the dose setting member 9 is moved from the stop 3c towards the dosing and actuation member 12 by engagement with the piston rod 4 and linear guidance of the mechanism holder 3. This reduces the fine spacing between the rear stop region of the dose setting member 9 and the front stop region of the dosing and actuating member 12, but on the other hand increases the fine spacing between the front stop region of the dose setting member 9 and the dispensing stop 3 c. The spacing between the rear, delivery stop 3c and the dose setting member 9 is the length of the path the dose setting member 9-and thus the piston rod 4-moves in the advancing direction during the delivery movement of the dose setting member 12 due to the threaded engagement. The sending stop 3c forms a front translation stop. During the dispensing movement, the piston rod 4 pushes with its front end against the piston and in the advancing direction towards the outlet of the ampoule 2, the front end of the piston rod 4 being formed by a plunger body connected to the piston rod 4, so that it cannot move in or opposite to the advancing direction. The longitudinal axis L constitutes the rotation and translation axis of the movement performed for dosing and dispensing the product.

The distance which is present between the dose setting member 9 and the dosing and actuating member 12 when the dose setting member 9 is pressed against the dispensing stop 3c during dosing corresponds to the selectable maximum product dose to be dispensed during dispensing. The stroke movement of the dosing and actuating element 12 has the same length for each delivery. The dosing sets only the distance between the dose setting member 9 and the dispensing stop 3c and thus the path length co-operated by the dosing and actuating member 12 and the dose setting member 9 during dispensing.

The braking function of the blocking means 8 and the braking cooperation which exists for this purpose between the piston rod 4 and the blocking means 8 are apparent from fig. 6 and 7. On the one hand, the blocking device 8 comprises two braking elements 8b for braking engagement, which, like the blocking element 8a in front of them, are each formed by an elastically flexible wheel block. In the exemplary embodiment, the blocking device 8 is made of one single annular element from which four resilient wheel blocks protrude on the abutment side. The wheel blocks are arranged in a uniform distribution over the circumference of the ring element. Two opposite wheel blocks form blocking elements 8a, and two further wheel blocks likewise arranged opposite form braking elements 8 b.

The piston rod 4 thus comprises two return-blocking means 6 formed on the outer surface of the opposite side and extending in the longitudinal direction of the piston rod 4, and two advance-braking means 7 likewise extending in the longitudinal direction of the piston rod 4 on the opposite side. The thread on the piston rod 4 for threaded engagement with the dose setting member 9 is formed by four remaining thread portions 5 extending almost over the entire length of the piston rod 4. The return blocking means 6 and the forward braking means 7 are each constituted by a row of teeth. However, although the teeth of the return stop 6 are made as saw-tooth-shaped teeth, narrowing in the advancement direction, comprising a stop zone directed rearwards and extending transversely to the advancement direction, the two rows of teeth forming the advancement stop 7 do not comprise a stop zone directed forwards with a comparable stop effect. The teeth of the forward brake 7 each present a tooth profile with a smaller slope than the return stop 6. The braking cooperation between the blocking means 8 and the advancement braking means 7 of the piston rod 4 is not intended to prevent the piston rod 4 from advancing, but only to make it more difficult to ensure that the piston rod 4 does not move in the advancement direction during dosing. The front side of the teeth of the forward brake 7 and the rear side of the braking element 8b which is in contact with the front side of the teeth of the forward brake 7 are shaped such that a threshold force which is not reached during the dosing process must be overcome in order to overcome the braking engagement. This threshold force is greater than the force required to move the tooth of the return blocking means 6 in the forward direction past the blocking element 8 a. The threshold force is preferably at least twice as large as the initial frictional force between the return blocking means 6 and the blocking element 8 a. The friction between the latter during the advancing movement likewise increases only gradually between two successive blocking engagements. Instead, the threshold force of the detent engagement must be immediately applied from one detent engagement to the next detent engagement at the beginning of the advancing motion. But the threshold force should not be so great as to make the user cumbersome during the transmission process.

In response to the movement of the dose setting member 9 when a dose is selected, the undesired forward movement of the piston rod is in principle also caused only by the blocking engagement of the blocking means 8. But this movement can be more reliably prevented by the detent engagement than by the mere blocking engagement.

The connection between the reservoir module 10 and the dosing and actuating module 30 is an arbitrary lock. On the one hand, there is a locking fit between the mechanism holder 3 and the housing part 11, which prevents relative movement in the axial direction. In addition to the latching engagement, the front housing parts 1, 3 and the rear housing part 11 are guided directly axially straight onto one another to prevent relative rotation when connected. The axial guide 3d of the mechanism holder 3, which forms a linear guide together with one or more corresponding mating elements of the rear housing part 11, can be seen clearly in fig. 5. The axial guide 3d is formed by a guide area on the guide rib; they may also be formed by guide areas located in axially extending grooves. An axial guide channel is thus obtained. These guide ribs are tapered axially to form an insertion funnel leading into the guide channel for one or more mating elements of the rear housing part 11. In order to better align the housing parts 1, 3 and 11 at the start of the connection, the guide ribs are also tapered in the radial direction. The one or more mating elements of the rear housing part 11 are preferably shaped like the axial portion 3d on the surface-opposite, i.e. inner surface area, of the rear housing part 11.

There is a latching engagement between the first female latching element 3a (fig. 5) of the mechanism holder 3 and a latching ring 20 connected to the rear housing part 11, so that it can move radially but not axially. The locking ring 20 forms a second male locking element 21 which directly engages the first locking element 3a in the radial direction. A locking/latching connection exists between the first latching element 3a and the second latching element 21, which prevents the storage module 10 and the dosing and actuating module 30 from moving axially relative to one another.

Fig. 3 and 4 show the blocking element 21 in blocking engagement with the blocking element 3 a. The blocking element 3a is formed by an annular bead and a groove extending around the outer surface of the mechanism holder 3. The annular stay forms a rear sidewall of the groove. The second latching element 21 is formed by a cam which projects radially inwardly from the inner surface of the latching ring 20 and is pushed radially inwardly in the latching engagement by a restoring device 24 over the inner surface area of the rear housing part 11 into the receiving latching element 3 a. The locking ring 20 is supported radially in its entirety on the inner surface region formed by the rear housing part 11 by means of a restoring means 24, so that the restoring means 24 pushes against the outer surface of the locking ring 20 approximately on the radial extension of the locking element 21. The locking ring 20 surrounds the mechanism holder 3 and is movable radially back and forth as a whole against the restoring force of the restoring means 24, so that the second locking element 21 can be moved into or out of locking engagement with the first locking element 3 a. The rear housing part 11 forms a tight sliding guide for the radial movement of the locking ring 20. On its side diametrically opposite the blocking element 21, the blocking ring 20 forms an unlocking button 22 for the user. In order to radially guide the restoring device 24, which is embodied as a compression spring, a guide cam projects radially from the outer surface region of the locking ring 20 facing away from the locking element 21.

Two blocking cams 23 which press radially outwards against the locking block 25 also project from the outer surface area of the locking ring 20 in the circumferential direction on both sides of the above-mentioned guide cam and axially behind the guide cam. Radial movement of the blocking element 21, which would result in the locking engagement being released, is prevented as a result of the blocking cam 23 pressing against the locking block 25. The locking engagement between the locking elements 3a and 21 is thus ensured by the locking block 25. In each position of the dosing and actuating element 12, a latching engagement is ensured, except for the release position assumed by the dosing and actuating element 12 at the end of its delivery movement. The release position thus coincides with the foremost displaced position which the dosing and actuating element 12 assumes when it presses against the dose setting member 9 during its dispensing movement, while a part of the dose setting member 9 presses against the dispensing stop 3c of the mechanism holder 3. Assuming that the dosing and actuating module 30 is not yet connected to the reservoir module, a mechanical stop for the dosing and actuating element 12 is formed by the stop element 31 of the dosing and actuating device. In an exemplary embodiment, a reset retaining ring for the reset indicator 17 forms the stop element 31. The dosing and actuating element 12 pressed against the above mentioned stop element 31 defines a release position of the dosing and actuating element 12 in this case, the release position defined by the stop element 31 corresponding to the release position defined by the dose setting member 9 pressed against the dispensing stop 3 c.

Fig. 8 shows a lock block 25. In the exemplary embodiment, it is made in one piece from one blocking slide. As shown in fig. 4, the locking block 25 comprises a plate-like body that extends axially when assembled. At one end, a stay 26 extends at right angles from the body. After assembly, the stays 26 extend radially up to the dosing and actuating element 12. The stay 26 serves to fasten the blocking block 25 to the dosing and actuating element 12, for which purpose the dosing and actuating element 12 comprises two annular stays formed on the outer surface area at an axial spacing, which form the following means 15a and 15 b. The front follower means 15a simultaneously also form a bearing collar for the return means 16. The locking piece 25 projects with its struts 26 into the annular gap formed between the followers 15a and 15b and is closed off axially tightly on both sides by the two followers 15a and 15 b.

At the front end facing away from the stay 26, the body of the locking block 25 is provided with an axial groove 27 which is open towards the front end of the locking block 25. This forms blocking tongues 28 extending axially on either side of the groove 27. The blocking cams 23 of the locking ring 20 are arranged such that each of the above-mentioned blocking cams 23 pushes against a blocking tongue 28, provided that the dosing and actuating element 12 is not in the release position. When the locking block 25 is moved axially, the restoring means 24 for the locking element 21 extend through the axial groove 27.

A recess groove 29 is also formed in the body of the locking block 25 and defines the release position of the dosing and actuating element 12. One notch groove 29 is provided for each blocking cam 23. The positions of the notch grooves 29 are chosen such that they cover only the blocking cams 23, thus allowing the blocking cams 23 to be inserted after the dosing and actuating element 12 has been advanced to its release position.

It will be clear that in a particularly alternative arrangement in the exemplary embodiment, a single blocking cam 23 can also be provided, so that the locking piece 25 comprises only one notch recess 29 and possibly also only one blocking tongue piece 28. In addition, the blocking block can in principle be made in one piece with the dosing and actuating element 12. But making it as a separate component offers advantages in terms of production, assembly and cooperation of the dosing and actuating element 12 with the piston rod 4. With regard to the installation length of the locking piece 25, it should also be noted that the locking piece 25 is supported on the inner surface region of the housing 11 on its outer side facing away from the locking element 21. This improves the stability of the secure latching engagement. The housing 11 preferably forms an axial guide for the locking piece 25.

Described below is the function of the injection device, wherein it is assumed that a new reservoir module 10 and a dosing and actuating module 30 that has been used at least once are assembled and then the product is delivered for the first time.

The dosing and actuating element 30 and the new storage module 10 are axially aligned with respect to each other such that their two longitudinal axes are flush with each other. The reservoir module 10 is then inserted through its rear end into the housing 11 of the dosing and actuating element 30, which is open to the front.

This centers the housing parts 1, 3 and the housing part 11 on the tapered end of the guide rib 3d of the mechanism holder 3. While sliding, the two housing parts are guided axially linearly onto one another in the rotational angle position preset by the linear guide until the housing parts 1, 3 and 11 assume a connecting end position in which the latching fit of the latching elements 3a and 21 can be established or can be set themselves.

The dosing and actuating element 12 is locked in a preset rotational angular position relative to the rear housing part 11. The linear guides of the housing parts 1, 3 and 11 and the rotational angle locking positions of the dosing and actuating element 12 are adjusted relative to each other such that a secure non-rotatable engagement between the dosing and actuating element 12 and the piston rod 4 is established in each locking position of the dosing and actuating element 12 and in each rotational angle position of the housing parts 1, 3 and 11 linearly guided to each other.

If the dosing and actuating element 12 is located in an axial position behind the release position relative to the housing part 11, the blocking element 21 is held in its radially innermost position by the blocking block 25. In this position of the blocking element 21, the dosing and actuating module 30 and the storage module 10 cannot be slid onto one another as far as the connection end position and therefore cannot be connected to one another, since the annular strut formed on the outer surface of the mechanism holder 3, which forms part of the first blocking element 3a, is initially pressed against the second blocking element 21.

The annular bead can be reduced tangentially to a short radial projection if it is ensured that the housing parts 1, 3 and 11 can only be fitted in the rotational angular position in which the projection is axially flush with the second latching element 21. The axial struts or radial projections can also form only the first blocking element 3a, since the main function of the first blocking element 3a is to allow a connection to be established between the reservoir module 10 and the dosing and actuating module 30 only when the dosing and actuating element 12 is in its release position. If this condition is fulfilled, the dosing and actuation element 12 will ensure that the dose setting member 9 is in its dose zero position pressed against the dispense stop 3c of the mechanism holder 3 when a connection between the reservoir module 10 and the dosing and actuation module 30 is established.

In order to satisfy the above conditions, the user pushes the dosing and actuating element 12 axially forwards with respect to the rear housing part 11 up to the release position. In this relative position between the rear housing part 11 and the dosing and actuating element 12, the blocking cam 23 can be moved into the recess groove 29 of the blocking block 25. The user therefore not only pushes the dosing and actuating element 12 at least into the release position, but at the same time pushes the first blocking element 20 out of the blocking engagement by means of the unlocking button 22. The storage module 10 can then be moved axially past the annular bead of the first blocking element 3a and can then be inserted into the rear housing part 11. The user may release the unlock button 22. As soon as the first blocking element 21 covers the second blocking element 3a, it snaps closed into the receiving blocking element 3a due to the force of the restoring device 24, so that a blocking fit is established. The reservoir module 10 and the dosing and actuating member 30 are then interconnected in a defined manner with respect to the dose setting member 9 and the piston rod 4. If the dose setting member 9 is still a slight distance from the dispensing stop 3c before the locking engagement is established, this distance is eliminated due to the dosing and actuation element 12 action required to establish the connection. The resulting product delivery is acceptable or even desirable for filling injection needles. This preferably resets the counting and indicating means 17 to zero.

In a defined initial state produced in this way, the user can dose the product. The product is dosed by rotating the dosing and actuating element 12 about the longitudinal axis L and relative to the housing part 11. Since the dosing follower 13 is fast and non-rotatably connected to the dosing and actuating element 12 and a part of it is fast and non-rotatably co-operating with the piston rod 4, the dosing and actuating element 12 moves with the piston rod 4 during its rotational dosing movement. Due to the threaded engagement between the piston rod 4 and the dose setting member 9 and the linear guidance of the dose setting member 9 by the mechanism holder 3, the dose setting member 9 performs an axial translational dosing movement towards the dosing and activating member 12, which is preset by the pitch of the reciprocating threaded engagement. The dosing and actuating member 12 forms a rear translational stop 12c, which rear translational stop 12c limits the translational dosing movement of the dose setting member 9 and thus the maximum dispensing stroke that can be set.

The counting and indicating means 17 count the dose units corresponding to the rotational angular positions of the dosing and actuating element 12 and indicate them by optical means.

Once the desired product dosage is selected, the dosing process is complete. The selected product dose is delivered by a delivery movement of the dosing and actuating element 12 directed in the direction of advance of the piston. During its dispensing movement, the dosing and actuating member 12 presses against and follows the dose setting member 9. The dispensing movement of the dosing and actuating element 12 and the dispensing of the product is ended when the dose setting member 9 is pressed against the dispensing stop 3c of the mechanism holder 3 during the dispensing movement. Once the user releases the dosing and actuating element 12, it is preferably moved back into the new initial position for dosing and dispensing the product again, counter to the advance direction, by the return means 16. The counting and indicating means 17 are preferably coupled to the dosing and actuating element 12 so that it has been reset back to zero at the same time. There may be means for counting and indicating the total amount of product that has been dispensed and thus the amount of product remaining in ampoule 2.

In order to disengage the reservoir module 10 from the dosing and actuating member 30, the dosing and actuating member 12 is advanced up to the release position, i.e. until it is pressed against the dose setting member 9. In this position, the user can again release the latching engagement by pressing the unlocking button 22, detaching the reservoir module 10 from the dosing and actuating element 30.

Fig. 9 to 13 show a longitudinal section and four cross sections of a second exemplary embodiment of an injection device. The injection device of the second exemplary embodiment is identical to the first exemplary embodiment with regard to the latching and latching block 25, so reference is made in this respect to the first exemplary embodiment. In particular, the latch block 25 of the second exemplary embodiment is identical to the first exemplary embodiment in all its functional details. The same is true for the blocking elements 3a and 21.

The position of the locking ring 20 and of the blocking cam 23 relative to the locking element 21 and relative to the locking block 25 in the initial state of the device can be seen particularly clearly from the cross sections in fig. 10, 11 and 12, to which reference is made in this respect also as a representation of the first exemplary embodiment.

The injection device of the second exemplary embodiment differs from the first exemplary embodiment in the mating of the components involved in the dosing process and in the progression of the movement. In addition to the function of the mechanism holder in the first exemplary embodiment, the mechanism holder in particular also fulfils the function of positioning the dose setting element in discrete rotational angular positions which can be changed with respect to the mechanism holder for dosing. In contrast, the blocking device of the second example embodiment is simpler than that of the first example embodiment. The following description is made mainly of differences from the first exemplary embodiment, wherein components having the same basic functions but differing in detail as those in the first exemplary embodiment are denoted by 30 plus the same last digit or are given the same reference numerals as those in the first exemplary embodiment. Without making statements with respect to the second exemplary embodiment, the corresponding statements with respect to the first exemplary embodiment apply to the second exemplary embodiment.

In the second exemplary embodiment, the dosing and actuating member 32 is fast and non-rotatably connected with the dose setting member 39, the dosing and actuating member 32 being axially linearly movable relative to the rear housing part 11 and rotatable around the longitudinal axis L. The dosing and actuating member 32 and the dose setting member 9 are movable relative to each other and to the housing parts 1, 3 and 11 in and opposite to the advancing direction. The piston rod 4 is secured against rotation by the mechanism holder 3. In cooperation with the blocking element of the blocking device 38 made in one piece on the mechanism holder 3, the return blocking device 6, which is functionally identical to the first exemplary embodiment, can prevent the piston rod 4 from moving opposite to the advancing direction, but allows it to move in the advancing direction. The blocking element constitutes both a return stop and a rotation stop for the piston rod 4. In addition, as in the first example embodiment described above, the dosing and actuating element 32 forms a sliding guide for the piston rod 4.

During the dosing process, the dosing and actuating element 32 performs the same rotational dosing movement as the dosing and actuating element 12 in the first exemplary embodiment. But the dose setting member 39 follows during the rotational dosing movement since the fit is tightened and cannot rotate. The threaded engagement between the piston rod 4 and the dose setting member 39 is also comparable to the first exemplary embodiment, so that due to the rotational dosing movement and the threaded engagement with the piston rod 4, one stop 39c formed by the dose setting member 39 is moved during dosing towards the front end of the dosing and actuating member 32 opposite to the advancing direction. In contrast to the first exemplary embodiment, the dose setting member 39 thus performs both a rotational dosing movement and a translational dosing movement relative to the front housing part during dosing, while the piston rod 4 remains stationary. Once the dosing is finished, the dosing and activating element 32's dispensing movement advances the piston rod 4a path length corresponding to the slight distance between the stop area of the dose setting element 39 set by the dosing and the dispensing stop 3c of the mechanism holder 3.

The translational dosing movement of the dose setting member 39 opposite to the forward direction is limited by a rear translational stop 11c formed directly by the rear housing part 11 itself. In the second exemplary embodiment, too, the axes of rotation and translation of the components involved in the product dosing and delivery process constitute the longitudinal axis L.

As in the first exemplary embodiment, the front housing parts 1, 3 form one sliding guide for the dose setting member 39. To form a sliding guide, the inner surface area of the mechanism holder 3 and the outer surface area of the dose setting member 39 are in sliding contact with each other. The dosing and actuation member 32 cooperates with an inner surface area of the dose setting member 39 forming a secure non-rotatable connection between the dose setting member 39 and the dosing and actuation member 32.

In the second example embodiment, the piston rod 4 itself comprises no braking means other than the return blocking means 6. Instead, the front side of the saw tooth of the return stop 6 likewise forms a detent on itself. The piston rod 4 of the second example embodiment may be replaced with the piston rod 4 of the first example embodiment. The mechanism holder 3 of the second exemplary embodiment therefore also has to form at least one braking element, preferably two braking elements, of the first exemplary embodiment in this case.

Fig. 14 to 16 show the mechanism holder 3 of the second example embodiment in a perspective view, a side view, and a sectional view a-a in the side view. As in the first exemplary embodiment, the mechanism holder 3 is embodied as a one-piece sleeve part, preferably as a plastic injection-molded part. It includes a projection 3e on the outer surface of the front sleeve portion. The front sleeve portion is inserted into the storage part 1 and is locked to the storage part 1 by the projection 3e at least non-detachably to the user.

As in the first exemplary embodiment, a blocking element 3e is formed on the intermediate sleeve portion of the mechanism holder 3.

A rear sleeve part connected with the blocking element 3a forms a plurality of axial guides 3d on its outer circumference. These axial guides 3d are constituted by guide ribs projecting radially on the outer circumference of the rear sleeve part. More precisely, the axial guide is formed by the axially extending straight side walls of the above-mentioned guide ribs, so that as in the first exemplary embodiment, an axial guide channel is obtained. These guide ribs project like fingers from the intermediate sleeve part as far as the rear end of the mechanism holder 3, where they taper axially. The axial guide 3d serves to guide the rear housing part 11 in a straight line when the storage module 10 is connected to the dosing and actuating element 30. As can be seen most clearly from fig. 9 and 11, the mating elements 11d project radially inwardly from the inner surface area of the rear housing part 11, corresponding in number and adapted in shape. A mating element 11d projects into each axial guide 3d and is guided linearly by the axial guide 3d when the front housing part 1, 3 and the rear housing part 11 are slid into connection with each other. This ensures that there is no relative rotation between the front housing part 1, 3 and the rear housing part 11 when a secure non-rotatable engagement is established between the dosing and actuating member 32 and the dose setting member 39 during connection.

Since the guide ribs are axially tapered at their rear ends, the guide channel is widened to an insertion funnel, and centering between the front housing part 1, 3 and the rear housing part 11 for connection purposes becomes easier. These guide ribs are also tapered radially at their ends relative to the surface area of the mechanism holder 3, which makes it easier to center the housing parts 1, 3 and 11 relative to one another into the rotational angle position preset by the axial guide 3 d.

Just as the front housing part 1, 3 and the rear housing part 11 are prevented from rotating relative to each other when slid into each other, the dose setting member 39 is also fixed relative to its rotational angular position relative to the front housing part 1, 3, the dose setting member 39 being detachably fixed to allow the rotational movement of the dose setting member 39 required to complete a dose. Thus, on the one hand, in order to allow the dose setting member 39 to perform a dosing movement, but to prevent an undesired dosing movement due to the connection established between the front housing part 1, 3 and the rear housing part 11, the dose setting member 39 is fixed in discrete rotational angular positions by the mechanism holder 3 by means of a releasable locking connection.

Fig. 17 to 20 show respective views of the dose setting member 39. In order to form a locking connection, a plurality of locking grooves 39g are formed on the outer surface area of the dose setting member 39, which are evenly distributed circumferentially apart. Each locking groove 39g is formed by a straight axially extending channel having a rounded profile extension in its cross-section.

The mechanism holder 3 is provided with two locking projections 3g (fig. 15 and 16). These two locking projections 3g project radially inward from the inner surface area of the mechanism holder 3 in the rear sleeve portion of the mechanism holder 3. Which are arranged diametrically opposite to each other. Each surface area of the mechanism holder 3 on which one of the locking projections 3g is formed forms a spring element 3f that is elastically deformable in the radial direction. Due to the elastic deformability and the rounded shape of the locking projection 3g, in combination with the rounded profile of the locking groove 39g, the locking engagement between the locking projection 3g and the opposing locking groove 39g can be released. This is necessary for selecting the dose. On the other hand, however, the locking fit is designed such that the dose setting member 39 is rotationally fixed sufficiently stable so that when the front housing part 1, 3 and the rear housing part 11 are connected, the dose setting member 39 does not exhibit any undesired dosing movement when the rotational coupling between the dosing and actuating member 32 and the dosing and actuating member 32 is established. The locking connection between the mechanism holder 3 and the dose setting member 39 has the advantageous boundary effect of a tactile signal during dosing. In order to maintain good elasticity of the spring element 3f, the rear sleeve section of the mechanism holder 3 is cut off in the region of the surface, so that the spring element 3f is held as a circumferentially extending annular segment which is axially free on both sides.

An axial guide 39d for the secure, non-rotatable engagement between the dose setting member 39 and the dosing and activating member 32 is similarly visible in fig. 17, 18 and 20. The dosing and actuating member 32 is provided with at least one mating element to obtain an axial linear guide, i.e. a rotational stop, between the dosing and actuating member 32 and the dose setting member 39. The axial guide 39d is likewise a guide channel formed by a plurality of guide ribs extending axially in a straight line. Each guiding rib tapers axially and radially at its rear end facing the dosing and actuating member 32, thereby facilitating centering between the dosing and actuating member 32 and the dose setting member 39 when a secure non-rotatable fit is established. The same design as the housing parts 1, 3 and 11 is therefore used for the axial linear guides of the dose setting member 39 and the dosing and actuating member 32.

For the sake of completeness, finally reference is also made to the dosing thread 39a and the delivery stop 39c of the dose setting member 39, which can be seen most clearly in fig. 18.

Finally, two rotational stops are provided for the dose setting member 39, which act at both axial end positions of the dose setting member 39. Reference is also made in this respect to fig. 22.

To prevent the piston rod 4 from moving back due to the rotational dosing movement of the dose setting member 39, a rotational stop 39h is formed at the front end of the dose setting member 39. In this forward position of the dose setting member 39, just after the product has been dispensed or before the dose is selected, the rotational stop 39h cooperates with a rotational counter stop 3h formed on the mechanism holder 3 (fig. 16). A rotation stop 39h axially projects from the front abutment side of the dose setting member 39, and a rotation counter stop 3h projects from an axially facing abutment region of the mechanism holder 3 forming a transmission stop 3c axially opposite the rotation stop 39 h. The cooperation between the rotational stop 39h and the rotational counter stop 3h is such that it allows a rotational dosing movement in a rotational direction, which results in a translational dosing movement of the dose setting member 39 away from the send stop 3c, but prevents a rotational dosing movement in the opposite rotational direction at the front axial end position.

In addition, another pair of rotation stoppers and rotation reversal stoppers are provided, which are shaped and fitted in substantially the same manner as the stoppers 3h and 39 h. The second pair of rotational stops mentioned above are on the one hand the rotational stops 39i axially protruding from the rear abutment area of the dose setting member 39 and on the other hand the rotational counter stops 11i axially protruding from the rear translational stop 11c facing the stop abutment area of the dose setting member 39, but cannot be seen in fig. 9 due to their small size. In this rear end position, the rear pair of rotational stops 11i/39i may prevent the piston rod 4 from moving in the forward direction due to a dosing movement of the dose setting member 39 towards the rear translational stop 11 c.

The height, i.e. the axial length, of all rotational stops 3h, 39h, 11i and 39i is adjusted to the pitch of the cooperating dosing threads of the piston rod 4 and the dose setting element 39. The rotational stops are sufficiently short in the axial direction that the rotational dosing movement of the moving dose setting member 39 away from the respective translational stop 3c or 11c is not hindered.

As can be seen from fig. 9, when the components of the reservoir module 10 are assembled, the dose setting element 39 is screwed onto the piston rod 4 up to a preset axial position. The piston rod 4 is then inserted together with the screwed-on dose setting member 39 from behind into the mechanism holder 3 until its blocking means 38 comes into blocking engagement with the return blocking means 6 of the piston rod 4, thereby establishing a secure non-rotatable engagement between the rotational stop 39h of the dose setting member 39 and the rotational counter-stop of the mechanism holder 3. Even when inserted into the mechanism holder 3, the dose setting member 39 is axially guided straight by the mechanism holder 3 by the locking engagement between the locking projections 3g and the locking recesses 39g until the dose setting member 39 is pressed against the send stop 3c of the mechanism holder 3. In this front end position of the dose setting member 39 relative to the mechanism holder 3a secure non-rotatable fit between the rotational stops 3h and 39h has been established.

In this state, the mechanism holder 3 and the storage part 1 to which the reservoir has been mounted are connected to each other.

In a later step, the rear housing part 11 of the completely assembled dosing and actuating element 30 is slid into the mechanism holder 3, wherein the mechanism holder 3 and the rear housing part 11 are centered relative to each other due to the axial guides 3d and the mating elements 11d of the rear housing part 11 and, once centered, are guided axially straight onto each other due to the guide fit. During the sliding of the rear housing part 11 onto the mechanism holder 3, the dosing and actuating element 32 comes into a secure, non-rotatable engagement with the dose setting member 39, wherein here again a certain centering can be made first with a linear guide corresponding to the axial guide 3d and the engagement element 11 d.

The dosing and actuating element 32 is in locking engagement with the rear housing part in discrete rotational angle positions, in which locking engagement, i.e. in each rotational angle locking position, is axially and linearly guided. The rotational angle difference between two consecutive rotational angle locking positions corresponds to one dose unit. The discrete rotational angular positions of the dose setting member 39 relative to the mechanism holder 3 (locking protrusions 3g and locking recesses 39g) on the one hand and the rotational angular locking position of the dosing and actuating member 32 relative to the rear housing part 11 on the other hand, are adjusted relative to each other such that the two housing parts 1, 3 and 11 always slide linearly past each other in one rotational angular position, such that the dose setting member 39 and the dosing and actuating member 32 are also aligned relative to each other for their secure, non-rotatable fit, such that there is no relative rotation between the components involved in the dosing process, while the storage module 10 is connected with the dosing and actuating member 30.

With regard to further details regarding the assembly of the injection device according to the second exemplary embodiment, in particular the establishment of the latching fit and the function, reference is made to the description of the first exemplary embodiment.

In the injection device according to the first exemplary embodiment, a rotational stop may also be provided which prevents an undesired response movement of the piston rod 4 in both axial end positions of the dose setting member 9 of the first exemplary embodiment. Fig. 21 shows two rotation stoppers made in the same manner as the rotation stopper in the second example embodiment. The rotation reversal stops formed on the housing parts 1, 3 and 11 in the second exemplary embodiment are formed in the first exemplary embodiment on the one hand by the blocking device 8 and on the other hand by the dosing and actuating element 12. This forms a plurality of rotational stops 8h on the abutment side of the blocking means 8 axially facing the dose setting member 9, which rotational stops protrude axially towards the dose setting member 9. Since the blocking means 8 is axially immovably mounted by the front housing part 1, 3 and is fast and non-rotatably connected with the piston rod 4, a rotational stop for the rotational dosing movement between the piston rod 4 and the dose setting member 9 is obtained by a front pair of rotational stops 8h/9 h. The second pair of rotational stops is formed between the dose setting member 9 and the rear translational stop 12 c. As in the second exemplary embodiment, a plurality of rotational stops 12i axially project from the abutment area of the translational stop 12c axially facing the dose setting member 9 towards the dose setting member 9. As in the second exemplary embodiment, the dose setting member 9 is provided with a rotational stop 9i at its rear side, which rotational stop 9i cooperates with a rotational stop 12i at a rear axial end position of the dose setting member 9. In the rear axial end position of the dose setting member 9, the rear pair of rotational stops 9i/12i only allows a rotational dosing movement which results in a translational dosing movement of the dose setting member 9 in the forward direction.

Reference numbers:

1 storage part, ampoule holder

2 reservoir, ampoule

3 mechanism holder

3a first blocking element

3b fixing device

3c send stop, translation stop

3d axial guide

3e projection

3f spring element

3g locking projection

3h rotation stop

4 piston rod

4a connecting part

5 threaded portion

6 Return-blocking device, dentition

7 advancing brake device, tooth row

8 blocking device

8a blocking element

8b braking element

8h rotation stop

9 dose setting element

9h rotation stop

9i rotation stopper

10 storage module

11 rear housing part

11d mating element

11i rotation stopper

12 dosing and actuating element

12i rotation stopper

13 quantitative follow-up device

14 closure

15a follow-up means, annular stays

15b follow-up means, ring-shaped stays

16 restoring device

17 counting and indicating device

18

19

20 locking ring

21 second blocking element

22 unlocking button

23 blocking cam

24 restoring device

25 latch block

26 follow-up means, stays

27 axial recess

28 stop tongue

29 notched groove

30 dosing and actuating element

31 stop element

32 dosing and actuating element

33-37

38 blocking device

39 dose setting member

39a quantitative screw thread

39c send stop

39d axial guide

39g locking groove, axial guide

39h rotation stop

39i rotation stopper

Claims (27)

1. A product dispensing apparatus comprising a reservoir module (10) and a dosing and actuating module (30) removably connected to said reservoir module, said reservoir module (10) comprising:

a) a front housing part (1, 3) of said product dispensing device comprising a reservoir (2) for a dispensable product, a blocking means (8; 38) and a first connecting means (3a, 3 d);

b) a piston housed in said reservoir (2) so that it can be displaced in an advancing direction towards the reservoir outlet to dispense the product;

c) and a piston rod (4), the piston rod (4) comprising a connection to said blocking means (8; 38) return blocking means (6) in blocking engagement, said blocking engagement preventing said piston rod (4) from moving relative to said front housing part (1, 3) opposite to said forward direction;

the dosing and actuating module (30) comprises:

d) a rear housing portion (11) of the product dispensing device, the rear housing portion (11) comprising a second connecting means (20, 21, 11d) for forming a removable connection between the reservoir module (10) and the dosing and actuating module (30) together with said first connecting means (3a, 3 d);

e) and a dosing and driving device (12; 32) by means of which dosing and driving means (12; 32) a dosing movement for selecting a product dose and a delivery movement for delivering a product dose are possible relative to at least one housing part (1, 3, 11);

wherein the product dispensing device further comprises a dose setting member (9; 39), the dose setting member (9; 39) being threadedly engaged with the piston rod (4) such that it is moved together with the piston rod (4) in an advancing direction by the dosing and driving means (12; 32) during said dispensing movement and is moved relative to the piston rod (4) opposite to the advancing direction during said dosing movement, said dosing movement being a rotational movement of the dosing and driving means (12; 32) about the longitudinal axis (L) of the piston rod (4).

2. Product dispensing device according to claim 1, wherein the first connecting means (3a, 3d) and the second connecting means (20, 21, 11d) form an axial linear guide (3d, 11d) to prevent the front housing part (1, 3) and the rear housing part (11) from rotating relative to each other when the front housing part (1, 3) and the rear housing part (11) are connected.

3. Product dispensing device according to claim 1, wherein the first connecting means (3a, 3d) comprises a first latching element (3a) and the second connecting means (20, 21, 11d) comprises a second latching element (21), said latching elements (3a, 21) being in latching engagement for axially securing the housing parts (1, 3, 11) to each other.

4. Product dispensing device according to claim 3, wherein at least one of the blocking elements (3a, 21) is connected to one of the housing parts (1, 3, 11) radially movably against a spring force.

5. Product dispensing device according to claim 1, wherein said dose setting element (9; 39) is axially linearly guided by the front housing part (1, 3).

6. The product dispensing device of claim 1 wherein the dose setting element (39) in each case cooperates with the front housing part (1, 3) in a preset rotational angular position, guided axially straight when cooperating, the cooperation being a locking cooperation.

7. Product dispensing device according to claim 1, wherein one locking projection (3g) and one locking recess (39g) are movable against a return spring force out of locking engagement, one of the locking projection (3g) and the locking recess (39g) being formed on the dose setting member (39) and the other on the front housing part (1, 3) and being in locking engagement with each other.

8. Product dispensing device according to claim 1, wherein the dose setting member (39) comprises at least one stop (39 h; 39i), which stop (39 h; 39i) in the dosing end position of the dose setting member (39) is in blocking engagement with one of the housing parts (1, 3, 11), said blocking engagement preventing a movement of the dose setting member (39) which movement of the dose setting member (39) causes a responsive movement of the piston rod (4) opposite to the advancing direction.

9. Product dispensing device according to claim 1, wherein the front housing part (1, 3) forms a dispensing stop (3c) for the dose setting member (9; 39), said dispensing stop limiting the dispensing movement in the forward direction.

10. Product dispensing device according to claim 1, wherein the dosing and driving means (32) co-operate with the dose setting member (39), wherein said co-operation moves with the dose setting member (39) during the dosing movement and allows the dosing and driving means (32) to move relative to the dose setting member (39) in and opposite to the advancing direction, wherein the dose setting member (39) forms a stop (39c) for the dosing and driving means (32), against which stop (39c) the dosing and driving means (32) pushes during its dispensing movement, thereby moving the dose setting member (39) in the advancing direction.

11. Product dispensing device according to claim 1, wherein the dosing and driving means (12) are mutually cooperating with the piston rod (4), wherein said cooperation moves with the piston rod (4) during the dosing movement, but allows a dispensing movement of the dosing and driving means (12) relative to the piston rod (4).

12. A storage module for a product dispensing apparatus, said storage module comprising:

a) a front housing part (1, 3) of said product dispensing device comprising a reservoir (2) for a dispensable product, a blocking means (8; 38) and a connection device (3a, 3d) for establishing a connection with a dosing and actuating module (30) of the product dispensing apparatus;

b) a piston housed in said reservoir (2) so that it can move in an advancing direction towards the reservoir outlet to dispense the product;

c) a piston rod (4) comprising a piston rod which is connected to said blocking means (8; 38) return blocking means (6) in blocking engagement, said blocking engagement preventing said piston rod (4) from moving relative to said front housing part (1, 3) opposite to said forward direction;

d) a dose setting member (9; 39) (ii) a The dose setting member (9; 39) is threadedly engaged with the piston rod (4) such that it moves together with the piston rod (4) in an advancing direction during the dispensing movement and moves relative to the piston rod (4) opposite to the advancing direction during the dosing movement, which is a rotational movement of the dosing and driving means about the longitudinal axis (L) of the piston rod (4).

13. A reservoir module according to claim 12 in which the blocking means (8; 38) is in a tight fit with the piston rod (4), said tight fit preventing the piston rod (4) from returning to a position it had before it moved in the forward direction, wherein the tight fit is not releasable.

14. Storage module according to claim 13, wherein the secure fit between the blocking means (8; 38) and the return blocking means (6) forms the secure fit.

15. A reservoir module according to claim 12, wherein the front housing part (1, 3) comprises a reservoir part (1) accommodating the reservoir (2) and a sleeve-shaped mechanism holder (3), the reservoir (2) and the sleeve-shaped mechanism holder (3) being manufactured separately and connected to each other such that a user cannot release the connection without damaging it, wherein the mechanism holder (3) holds the piston rod (4).

16. The reservoir module according to claim 15, wherein the mechanism holder (3) forms a dispense stop (3c) for the dose setting member (9; 39) to limit the dispense movement, wherein the dosing movement moves the dose setting member (9; 39) in a direction opposite to the advancing direction, away from said dispense stop (3 c).

17. A reservoir module according to claim 12 wherein the front housing part (1, 3) forms a sliding guide for the dose setting member (9; 39).

18. A reservoir module according to claim 12 wherein the front housing part (1, 3) guides the dose setting member (9; 39) axially straight.

19. A reservoir module according to claim 12 in which the dose setting element (39) in each case detachably cooperates with the front housing part (1, 3) in a preset rotational angular position, guided in an axial straight line when cooperating, the cooperation being a locking cooperation.

20. A reservoir module according to claim 12 wherein a locking projection (3g) and a locking recess (39g) are in locking engagement with each other and are movable out of locking engagement against a return spring force, one of the locking projection (3g) and locking recess (39g) being formed on the front housing part (1, 3) and the other on the dose setting member (39).

21. A reservoir module according to claim 12 in which an axial guide (3d) comprising at least one straight axial guide area is formed on the front housing part (1, 3).

22. A reservoir module according to claim 12, wherein the dose setting element (39) and the front housing part (1, 3) each comprise at least one stop (3h, 39h), which stops (3h, 39h) cooperate in a front dosing end position of the dose setting element (39) to prevent a movement of the dose setting element (39), which movement of the dose setting element (39) causes a responsive movement of the piston rod (4) opposite to the advancing direction.

23. The reservoir module according to claim 12, wherein the blocking means (38) is immovably connected with the front housing part (1, 3) and forms a rotational stop preventing the piston rod (4) from rotating relative to the front housing part (1, 3).

24. A reservoir module according to claim 12 in which the blocking means (8) is mounted by the front housing part (1, 3) such that it can rotate about the longitudinal axis of the piston rod (4) but cannot move opposite to the forward direction.

25. A reservoir module according to claim 12 in which the piston rod (4) comprises a forward stop means (7), the blocking means (8) of the front housing part being in braking engagement with said forward stop means (7), said braking engagement making it more difficult for the piston rod (4) to move in the forward direction.

26. A reservoir module according to claim 12, wherein the return blocking means (6) of the piston rod (4) are constituted by at least one row of saw-tooth teeth.

27. The reservoir module of claim 12, wherein the reservoir module (10) is a disposable module arranged to be replaced in its entirety when the reservoir (2) is emptied.