WO1990003816A1

WO1990003816A1 - Disposable injection device

Info

Publication number: WO1990003816A1
Application number: PCT/AT1989/000088
Authority: WO
Inventors: Ewald Pickhard
Original assignee: Ewald Pickhard
Priority date: 1988-10-03
Filing date: 1989-10-03
Publication date: 1990-04-19
Also published as: AU4337989A; HU895714D0; BR8907685A; KR900701341A

Abstract

A disposable injection device (1) has an injection cylinder (2) that contains a piston (8) and a piston rod (6) linked to the piston in particular by a coupling device (7). The piston rod is preferably longer than the injection cylinder (2). On the side of the ampule that faces away from the piston rod (6) is arranged a coupling arrangement (3) for coupling an injection needle (4) to the injection cylinder (2). A trigger (9) and/or a warrant seal (27) are coupled to the piston (8) and/or to the piston rod (6).

Description

Single-use injection device

The invention relates to an injection device for single use as described in the preamble of claim 1. .

Various injection syringes are already known which can be provided with different safety devices in order to ensure that the injection devices are used once. In order to avoid multiple use, it is already "known - according to GB-OS 2 195 537 by the same applicant - to surround the injection needle with an originality seal, for example a protective cover. When using an injection syringe, this tamper-evident seal and the protective cap must now be removed, so that after the use of the injection device, the destruction of the tamper-evident seal can be recognized at any time and thus it can be determined whether the injection device has already been used or not. In addition, it is also already known to provide in the syringes themselves, for example, between the syringe needles and the syringe cylinders, by tamper-evident closures formed by membranes or the like, which are only sealed immediately before the injection device is used. be thrust so that the medicament is sealed in the syringe barrel until it is actually used. It is also disadvantageous in these injection devices that after the medication has been ejected from the syringe barrel, by actuating the syringe plunger, another medication can be sucked into its syringe barrel and the injection device can thus be used a second time in an unauthorized manner. This poses a great danger, particularly in countries with low hygiene awareness, which in many cases leads to an epidemic spread of mostly infectious diseases, in particular AIDS.

The present invention is now based on the object to provide an injection device that can be used for filling a further or new Medikamen¬ tes after the ejection ^• preferably a small amount of medicament no more.

This object of the invention is achieved by the features specified in the characterizing part ^'of the patent claim 1. The surprising advantage of this solution is that after a movement of the piston rod with the piston in the direction of the syringe needle, a safety device is activated which reliably prevents the piston from moving backward away from the injection needle in the direction of the piston rod, or the syringe cylinder or the piston destroyed. This solution, which appears to be surprisingly simple, now makes it possible for an injection device to be destroyed at best, even with the use of brute force, but to prevent multiple use of the injection device. A further development according to claim 2 is advantageous, since regardless of whether the entire amount of medication has been squeezed out of the syringe cylinder or only a small part of the medication has been squeezed out, the safety device can be activated and the pulling up of another medicament can be reliably prevented .

A further development according to claim 3 is also expedient. It is advantageous here that the locking ring is taken along by the piston during movements away from the injection needle, so that any medication can also be sucked into the syringe cylinder in the injection device according to the invention can. If, on the other hand, the syringe cylinder is filled with the necessary medication and the plunger with the plunger rod is adjusted only a small amount, in particular a path corresponding to a thickness of the locking ring parallel to the longitudinal axis of the syringe cylinder, in the direction of the injection needle, the triggering device is activated activated. Carrying the piston is then only possible when shear forces are exerted in the direction of the injection device, but not when tensile forces are exerted, since the drive connection between the piston rod and the piston is released or is released when tensile forces are exerted.

Another development is described in claim 4 ben. This design has the advantage that in the event of a relative displacement between the piston and the securing ring of the triggering device, the coupling elements are released in their radial direction of movement, and thus a force-transmitting movement between the piston and the piston rod only in the direction of the piston It is possible to squeeze a medicament through the injection needle. However, an embodiment according to claim 5 is also possible. As a result, a higher friction or holding force is built up between the inner wall of the syringe cylinder and the locking ring, which holds the locking ring securely in the syringe cylinder when the piston rod moves in the direction of the piston, so that the coupling elements of the coupling device released between the piston rod and piston.

A further development according to claim S is also advantageous, as a result of which a relative movement between the securing ring and the piston or piston rod is promoted without the action of an external force.

Furthermore, an embodiment according to claim 7 is also possible, since this provides a non-positive connection when the medicament is drawn up, in which case the plunger is moved in the direction of the plunger rod or the open end of the syringe cylinder, while the latter is slight - Most movement in the opposite direction

Snap arms move out of the locking ring and can thus be transmitted to the piston with only more compressive forces, since when a tensile force is exerted, the now free snap arms pass over the bulge of the attachment of the piston and the piston rod is thus uncoupled.

Another development describes the patent claim 8, whereby when the piston or the piston rod moves in the direction of the injection needle through the oblique surfaces of the piston rod or the coupling parts of the piston rod, the retaining ring is pressed with increasing force against the inner wall of the syringe barrel un _{d is} thus fixed in its position, and the desired relative movement between the coupling elements and the see- Ring have taken place and the coupling arms are released in the radial direction. Of course, it is also possible to connect the radially adjustable snap arms to the piston instead of the piston rod. The advantage of this solution also lies in the fact that, during transport or in the event of strongly fluctuating tolerances, the locking rings cannot move out of their position surrounding the coupling elements without the application of force, but this relative displacement to release the coupling elements only by applying force is possible from the outside.

Another embodiment variant is protected in claim 9. As a result, after the piston has been displaced in the direction of the injection needle, the retaining ring is no longer carried by the driver and remains in its position pressed against the inner wall of the syringe barrel. As a result, the spring comes out over the extensions and, with its roughened or ground ends, is guided along the inner wall of the syringe barrel. The inner wall is cut open or destroyed. If, in addition, an attempt is made to move the plunger back in a direction opposite the injection needle in order to suck up another medicament, the spring expands against the inner wall and, if at all, the plunger can only be pulled back by destroying the inside of the syringe barrel, as a result of which a leak between Piston and syringe barrel inside is reached, so that usually no more medication can be drawn up.

However, an embodiment according to claim 10 is also possible. When the piston is pulled back again in a direction opposite to the injection needle, the clamping action is increased due to the angled extensions and, if necessary, by the cutting edges or claws the surface of the syringe barrel is destroyed in such a way that no sealing seal between the plunger and the barrel and therefore no vacuum for drawing in a medicament can be generated in the syringe barrel area facing the injection needle.

Another development is characterized in claim 11, whereby in any case a security against undesired use is prevented even if the inner wall of the syringe cylinder is destroyed, since the drive connection between the piston rod and the piston is released by pulling out the coupling pins connected to the spring and this means that it is no longer possible to carry the piston with the piston rod when a tensile force is exerted.

An embodiment according to claim 12 is also advantageous, as a result of which the support members run onto the attachment surfaces of the retaining ring and press them apart against the inner wall of the syringe barrel via the cone-shaped attachment surfaces and clamp them against one another in such a way that a further backward movement of the piston does not occur is more possible.

It is also possible, however, to have an embodiment according to claim 13. This results in a self-locking between the plunger and the locking ring and thus the syringe barrel, so that the plunger only moves in the direction and counter to the injection needle with extremely large forces which already destroy the injection device can be.

Another further development is described in claim 14. This achieves a predefined radial contact pressure of the retaining ring on the inner wall of the syringe barrel, so that there is certainly a relative displacement between the piston rod or the piston and the locking ring is reached, so that the coupling device between the piston and the piston rod is reliably released or unlocked.

The embodiment according to claim 15 is advantageous, whereby it is ensured that the locking ring is displaced relative to the coupling device by the amount which ensures safe uncoupling of the coupling elements.

Another embodiment variant is disclosed in claim 16. By designing the coupling elements with a control edge distanced from the contact surface of the piston, it is surprisingly easy to carry out a lifting height defined by this control edge with the piston from an end position distanced from the outlet in the direction of the outlet and again in the direction of the distanced end position. without thereby already releasing the coupling element, the piston by the coupling elements of the support arms. This lifting height can be selected by this design so that the volume change which can be achieved therewith after the application of a medicament or a solution to be injected before the application, the process of expelling e.g. with aspirated air or after the punctuation and before the injection of the drug depot, the process of aspiration, in particular blood aspiration, is also made possible.

Furthermore, an embodiment according to claim 17 is also provided, whereby a guide surface is provided on the coupling element in a surprisingly simple manner, which causes the piston rod to be guided. However, further development according to claim 18 is also possible. This configuration ensures that the central guidance of the piston rod takes place in cooperation with the control strip on the coupling element with the locking ring over the entire lifting height.

An embodiment according to claim 19 is also possible. The space required for the retaining ring in the free space after the triggering process is thus kept small, which results in smaller dimensions overall for an injection device.

Another embodiment variant is provided according to claim 20. This is surprisingly simple to ensure that there is no frictional connection between the control strip or the control surface of the coupling elements and the securing ring.

However, an embodiment according to claim 21 is also possible. This ensures that the coupling elements, which are elastic in the radial direction, can spring open sufficiently, which surprisingly simply ensures that the coupling device is uncoupled.

Another development is described in claim 22. As a result, the relative movement between the piston rod moved in the direction of the injection needle and the locking ring which is immobile relative to the syringe barrel means that the latter is taken up by the free space. As a result, the coupling elements which are elastic in the radial direction can spring open and release the coupling element arranged on the piston, as a result of which the piston can only be moved further in the direction of the outlet in order to inject or expel the medicament located in front of the piston. bump. A movement of the piston in the direction of the end position distant from the outlet in order to be able to draw up another medicament or a further solution is therefore no longer possible.

However, an embodiment according to claim 23 is also possible. This surprisingly simply prevents an unintentional renewed coupling of the already released trigger device when the piston rod makes a premature counter-movement.

Another embodiment variant is provided according to claim 24, whereby a secure holding of the piston is guaranteed and the longitudinal mobility between the latching arms and the piston can be used in a simple manner for decoupling.

A further development according to patent claim 25 is also advantageous, since the latching arms spread apart on the expanding core as a result of the arresting arms and thus the coupling connection between the piston rod and the piston is released. If the opening element or the expanding core is provided with a cone angle, which brings about a self-locking effect or enables a latching in the latching arms, then a re-engagement and thus a drive connection between the piston rod and piston is prevented with a high degree of certainty. However, multiple use of the injection device is also impossible.

Another embodiment describes patent claim 26. This embodiment offers the advantage that, depending on the distance between the projections of the piston and the recess in the expansion ring, unhindered forward and backward movement of the piston is possible, as a result of which, for example, _A s _D iπeren with such a trained Inktionvorπch- tion is possible, however, when the solution is completely squeezed out of the interior of the injection device, the latching arms snap into the recesses of the expansion ring with their locking lugs and are thus held in an open position which re-engages the locking lugs of the locking arms in the projections should be reliably prevented on the rear side of the piston and thus also a multiple use of the injection device is excluded.

In one embodiment according to claim 27, the connection between the piston rod and the piston is made in a surprisingly simple manner, so that the piston can be moved in the direction of the injection needle by means of the piston rod for drawing up the medicament, but after the medication has been squeezed out, the Preventing the piston from refilling the injection device.

An embodiment according to claim 28 is also advantageous. This enables the clutch device to be activated due to the relative movement between the piston and the piston rod.

However, an embodiment according to claim 29 is also possible, as a result of which a positively actuated uncoupling is achieved when the piston rod moves forward in the direction of the piston.

Training according to claim 30 is also possible. As a result, a very compact shape for the clutch device and a further guide arrangement on the piston can be achieved with very small dimensions of the components and thus of the injection device as a whole. In the same way, a further development according to claim 31 is also possible. Due to the integrated arrangement of the coupling elements on the piston rod, additional components can be saved, as a result of which the assembly effort is reduced and the costs for the production of such parts are saved, while at the same time increasing the functional reliability.

However, a further development according to patent claim 32 is also advantageous, as a result of which the coupling elements can automatically move from a position of use into a rest position or a disengagement position.

An embodiment according to claim 33 is also advantageous, as a result of which the coupling elements are forced to remain in a position of use and, without further devices, are ensured that they come to a defined rest position after this state of constraint has been removed.

Furthermore, an arrangement according to claim 34 is also possible, whereby an unintentional jamming of the coupling elements and an undesired entrainment of the piston after the piston and piston rod have been uncoupled can be prevented.

However, a further development according to claim 35 is also possible. This makes it surprisingly easy to form the drive connection between the piston rod and the piston by optionally forming coupling elements on the piston or else on the piston rod.

A further development according to claim 35 is also advantageous, as a result of which, after the coupling element has been uncoupled or relaxed, the coupling element returns to its original position and the coupling elements thereby become disengaged. Furthermore, an embodiment according to claim 37 is also possible, as a result of which a sufficiently secure transmission of force between the piston rod and the piston is ensured during the drawing up of the medicament into the cylinder chamber, so that failure of the injection device is reliably prevented.

Another development is described in claim 38, whereby the risk of malfunction of the coupling device is effectively prevented.

An embodiment according to claim 39 is also advantageous because it enables the coupling device to be installed in the rest position of the coupling elements and the position to be used after installation by interposing the actuator.

However, an embodiment according to claim 40 is also possible because it allows the actuator to be moved into an area in which the coupling elements can assume their rest position.

Furthermore, training according to claim 41 is also possible, as a result of which the plunger can be moved from an initial position for filling the syringe barrel to a starting position for injecting.

Further advantageous refinements of the injection device according to the invention for single use are described in the further subclaims.

Further advantages result from the features characterized in the further patent claims. For a better understanding of the invention, this will be explained in more detail using the exemplary embodiments shown in the drawings.

Show it:

1 shows an injection device in a side view, cut prior to the drawing up of a medicament into the syringe barrel;

Figure 2 is a side view of the syringe barrel filled with medication;

3 shows the injection device after the medication has been pressed out and the action of a tensile force on the

Side view of the piston rod;

4 shows the injection device according to FIGS. 1 to 3 in

Front view cut along the lines IIII-IIII in Fig.1;

5 shows a side view of part of an injection device with an embodiment variant of a trigger device according to the invention;

6 shows the side view of the injection device according to FIG. 4 after activation of the triggering device;

P - 7 a part of an injection device with a differently designed triggering device according to the invention in side view; 8 shows the injection device according to FIG. 7 in a front view, cut along the lines VIII-VIII in FIG. 7;

9 shows another triggering device for an injection device, cut in a side view and a simplified schematic illustration;

10 shows a part of an injection device with a trigger device according to the invention of a different design, in a side view, in section;

11 shows the injection device according to FIG. 10 with a position of the piston removed from the outlet in a side view, cut;

12 shows a part of an injection device with another triggering device in a side view, cut away;

13 shows another embodiment of an injection device according to the invention with a positively actuated opening device in a side view and in a greatly simplified schematic representation;

14 shows another embodiment variant of an injection device according to the invention with a positively actuated opening organ, cut in a side view and a greatly simplified schematic illustration; __ _^

15 shows an injection device designed according to the invention in a side view, in section, in a simplified schematic representation; 16 shows a part of the injection device according to FIG. 15 in a side view with the coupling elements unlocked;

17 shows a side view of a variant of an actuator of an injection device according to the invention designed with an unlocking device;

18 a different embodiment variant of an actuator for a coupling device according to the invention of the injection device in a side view, in section;

19 shows another embodiment of an actuator of a coupling device of the injection device designed according to the invention in a side view, in section, in a highly simplified schematic illustration;

20 shows a possible embodiment of an actuator in

Side view;

Fig. 21 shows another embodiment of an actuator in

Side view;

22 shows a further embodiment of a coupling device of the injection device according to the invention in FIG

Side view, cut;

23 shows an injection device according to FIG. 22 with the coupling elements in the uncoupled position;

24 shows another embodiment of a coupling device according to the invention of the injection device in a side view, in section; 25 shows a section through a disposable syringe according to the invention, the piston end face with the locking member being shown at a distance from the end position;

«-_

26 shows a section analogous to FIG. 25 through the front section of the syringe with the latching element engaged;

0 Fig> 27 the plunger when receiving a used cannula;

2B shows the front section of the disposable syringe after removal of the cannula;

29 shows the cannula secured in the interior of the plunger;

30 shows an enlarged illustration of a second embodiment of the foremost piston section with the locking member before it enters and locks into place

Syringe cone;

31 shows a section through an injection device according to the invention in side view with another embodiment for a tamper-evident device or triggering device.

32 shows the side view of the injection device according to FIG. 31 after a large part of the liquid has been pressed out;

33 shows the injection device according to FIGS. 31 and 32 with an intermediate position of the triggering device or tamper-evident device during aspiration; 34 shows a side view of part of an injection device designed according to the invention, with a triggering or tamper-evident device that allows aspiration;

FIG. 35 shows the injection device according to FIG. 34 in a side view when the triggering or locking device has been triggered;

Pig- 36 a piston of the injection device according to Figure 34 in section along the lines XXXVI-XXXVI in Figure 34;

37 shows a piston of the injection device according to FIGS. 34 to 36 in section along lines XXXVII-XXXVII in FIG. 35;

38 is another side view of another embodiment of an injection device according to the invention with a triggering or tamper-evident device that allows aspiration.

1 shows an injection device 1, which consists of a syringe cylinder 2 and an injection needle 4 connected to it via a coupling arrangement 3. The coupling arrangement 3 is arranged on a tubular outlet 5 of the syringe cylinder 2. In the interior of the syringe cylinder 2, a piston rod 6 is arranged displaceably in the longitudinal direction thereof and is connected in motion to a piston B via a coupling device 7. A triggering device 9 is assigned to the clutch device 7. The piston 8 can consist of a rubber or plastic part or a corresponding plastic insert, on the circumference of which sealing elements, such as O-rings or rubber sleeves or the like, are arranged. With this rubber the piston 8 rests against an inner wall 10 of the syringe barrel and divides it into a cylinder chamber 11 connected to the outlet 5 and a cylinder chamber 13 assigned to an opening 12 of the syringe barrel 2.

A coupling element 15, for example a bulge-like thickening, is connected to the piston 8 via an extension 14 from the piston 8. Between this thickening and the piston 8 engage from the inner wall 10 of the syringe cylinder 2 with their projections 16 as snap arms designed in the radial direction elastically deformable coupling elements 17. The coupling elements 15 and 17 are fixed in their engaged position by a trigger device 9 designed as a locking ring 18. The safety ring 18 can consist of a closed ring or also of a C-shaped ring or of two half rings. These are arranged on the sides of the coupling elements 17 opposite the projections 16, the support arms 19 and the inner wall 10 of the syringe barrel. The securing ring 18 has a circular ring width that is greater than a distance 20 between the support arms 19 and the inner wall 10 of the syringe barrel less an overlap width 21 between the coupling elements 15 and 17. This ensures that as long as the retaining ring 18 is in its position in contact with the piston θ, the coupling elements 17 cannot deform radially in the direction of the inner wall 10 and thus a drive connection between the piston rod 6 and the piston 8 consists. Now, after mounting the injection needle 4 with the piston rod 6, which, like the syringe cylinder 2 can be provided with handles 22 for easier operation, is pulled out of the syringe cylinder 2, as can best be seen in FIG. 2, while the injection needle 4 in an open taking medication is immersed, the vacuum created by the retraction of the piston 8 in the cylinder chamber 11 draws in medication 23 or a body fluid, indicated schematically by small lines. If a sufficient amount of medication 23 is now accommodated in the cylinder chamber 11, the medication after the injection needle 4 has been inserted into a human or animal body is pressed out by the injection needle 4 by pressing the piston 8 in the direction of the outlet 5.

In order to prevent the injection device 1 from being refilled with a medication 23 after a large part of the medication 23 present in the cylinder chamber 11 has been dispensed, the triggering device 9 is provided. This works in such a way that when the piston rod 6 moves with the piston 8 in the direction of the outlet 5 or the injection needle 4, the retaining ring 18, which is under a biasing force directed radially outward against the inner wall 10 of the syringe cylinder 2, passes through the latter facing smooth surfaces of the support arms 19 which are arranged parallel to the associated inner side of the locking ring 18 is not taken. The piston rod 6 and the piston 8 therefore move relative to the locking ring 18 in the direction of the outlet 5 or the injection needle 4. The locking ring 18 therefore remains in its position because, due to the radial preload, the holding force built up in connection with the coefficient of friction between the inner wall 10 and the locking ring 18 is greater than any adhesion that may exist between the smooth surfaces of the support arms 19 and the inner surface facing them of the locking ring 18. This relative movement of the Sicherungs¬ ring 18 against the piston 8 is not the least possible because he _b away as opposed to a movement from the outlet 5 ei he _d, the locking ring 18 on the piston 8 supported can and forcibly pushed in the opposite direction between the support arms 19 and the piston 8, a free space 24 is arranged which is sufficient to allow radial movement of the coupling elements 17 or the support arms 19 and projections 16 connected to them. This free space 24 must have at least a length which corresponds to a length 26 of the support arms 19 running parallel to a central axis 25 of the syringe cylinder 2. If the piston has now been moved at least by the length 26 in the direction of the outlet 5, the locking ring 18 is in the free space

24, as shown in Fig. 2 in thin lines. From this moment on, the injection device 1 can no longer take any medication.

Like FIG. 3, namely, when a tensile force 26 'is exerted on the piston 8, the coupling elements 17 — as shown by thin lines in FIG. 3 — are deformed radially outward in the direction of the inner wall 10, as a result of which the projections 16 emerge from the undercut between the coupling elements 15 formed by a thickening and accordingly the piston rod 6 detaches from the piston 8 and can be pulled out of the syringe cylinder 2 relative to the piston 8.

Since even if the piston 8 would also be pushed out manually, for example, the piston with the locking ring centered in the correct position can only be reinserted into the position shown in FIG It is unlikely that medical personnel in developing countries will assemble the injection device 1 in order to use it a second time contrary to the hygienic regulations for injecting medication 23. It can be seen from FIG. 4 that the piston rod 6 has three coupling elements 17 which are evenly distributed over the circumference and which engage between the coupling element 15 or the thickening and the piston 8.

5 and 6 show another embodiment variant of an injection device 1 according to the invention. Since the basic structure of the injection device is the same, the same reference numerals are used for the same parts as in the figures described above.

The injection device 1 again consists of a syringe cylinder 2, an outlet 5 onto which an injection needle 4 can be attached via a coupling arrangement, and a piston 8 which is movable inside the syringe cylinder 2 and which is coupled to the piston rod 6, for example via a screw connection or can also be made in one piece with this. In the area of the piston 8 of the piston rod 6, a triggering device 9 is again provided, which interacts with a tamper-evident device 27. This tamper-evident device 27 consists, for example, of an approximately V-shaped spring element 28, for example a flat spring made of steel or any other material, for example also a plastic spring with metal parts which are arranged in the leg end regions and cast or otherwise connected to it. The spring element 28 is held in a slot 29 in a projection 30 molded onto the piston in the region of its base. The two leg ends 31 may also, as shown in the drawing, even in Rich¬ the inner wall 10 having angled projections 32 tung be seen ver¬ that ric ausge¬ approximately perpendicular to the inner wall 10 are tet _h. These angled extensions can also be sanded in their frontal areas and provided with cutting edges or scratching surfaces or claws. These are supported in the position shown in FIG. 5, prepared for receiving the medicament, in which the injection device 1 is still unused, in an inner surface 33 which is marked by a

Locking ring 34 formed trigger device 9. While an outer circumferential surface 35 lies with an exact fit and, if appropriate, under radial prestress on the inner wall 10, an inner diameter 36 is larger than an outer diameter 37 of the piston rod in this area. Thus, the locking ring 34 sits fairly strictly in the syringe barrel 2. If a medicament is now sucked in through the schematically illustrated injection needle 4, the piston 8 is moved together with the piston rod 6 in a direction opposite the outlet 5, the locking ring 34 being moved through the circle ¬ ring 38 protruding over the outer diameter 37 of the piston 8 entrains the locking ring 34. The user of such an injection device 1 must exert a somewhat greater pulling force, but independently of this the joint movement of the piston 8 with the piston rod 6 is perfectly possible. If a sufficient amount of medication 23 is now taken up in the syringe, this medication can be dispensed to a person or an animal, for which purpose the piston 8 with the piston rod 6 is moved in the direction of the outlet 5 - arrow 39. Since there is now a corresponding distance between the piston rod 6 and the inner diameter 36 of the bore of the locking ring 34, but the locking ring 34 is prestressed in the direction of the inner wall 10, the locking ring remains in its position and it is pushed forward by the piston rod 6 the tamper-evident device 27 entrained via the slot 29 in the piston 8 moves relative to the retaining ring 34, so that the leg ends 31 or extensions 32 emerge from the retaining ring 34 and through the spring element 28 inherent spring force against the inner wall 10 of the syringe barrel 2 are pressed. When the piston 8 is pushed forward in the direction of the outlet 5, the surface of the syringe barrel 2 is already roughened or, with a corresponding design with claws or cutting edges, is permanently destroyed such that a tight seal between the inner wall 10 and the piston 8 during a possible backward movement of the piston 8 against the arrow 39 can no longer be reached.

If a user tries in an unauthorized manner to use the injection device 1 a second time to dispense a medicament and if he wants to pull the piston 8 back over the piston rod 6 against the direction of the arrow 39, the spring element 28 still spreads stronger in the walls, and an even stronger tightening of the piston rod 6 either destroys the injection device 1, for example by breaking off the handles 22, or the piston rod 6 breaks in a predefined weakening area 40, which is caused by a material weakening of the piston 8 can be defined or formed in cross section. But even if there is no destruction of the coupling device between the piston rod 6 and the piston 8, the retraction of the spring element 28 by means of the extensions 32 destroys the inner wall in such a way that there is insufficient vacuum in the cylinder chamber 11 ¬ sucking a drug 23 can be built.

After the piston 8 has been moved so far in the direction of the arrow 39 that the spring element 28 with its extensions 32 lies against the inner wall 10 of the syringe barrel 2, it is pushed along via a further driving ring 41. How better 5, it is also possible that the driver 38 is arranged on its own central part 42, in which a piston rod body 43 is snapped.

This Ausbild.ung has the advantage that the locking ring 34 is always immediately behind the driver 38. If the securing ring in its end region facing the piston 8 is now provided with an attachment surface 44 which is inclined towards the central axis 25, the locking ring 34 would move due to the pretensioning against the inner wall 10 when the piston 8 moves against the direction indicated by the arrow 39 remain standing, and the spring element 28 entrained through the slot 29 in the piston 8 run onto these extension surfaces 44 and are additionally spread against the inner wall 10, so that a further movement of the piston against the direction of arrow 39 would be impossible. This also ensures that the piston 8 after a medicament has been drawn up and that part of the medicament has been pressed out can be moved by a maximum of the distance between the driver 38 and the piston rod body 43 or also a stop.

Instead of a U- or V-shaped spring element, the tamper-evident device 27 can also be formed by separate S- or L-shaped brackets made of flat material or steel wire. The spring elements or wire brackets can be fastened in the piston 8 by means of ultrasound embedding or gluing. It is also possible to find the sufficiency with only one spring element resting against one point of the inner wall of the syringe cylinder.

Another embodiment of the triggering device 9 is shown in FIGS. 7 and 8. The embodiment corresponds essentially to that shown in FIGS. 5 and 6, so that again the same reference numerals are used for the same parts. In addition, in this embodiment the driver 38 is provided with a nose or spring 45 which engages in a slot 46 of the C-shaped locking ring 34. A width 47 of the spring 45 is greater than a distance between two opposite end faces 48 of the locking ring 34 in the relaxed state of the locking ring 34.

Now is the friction surface between the end faces 48 and

Spring 45 is considerably less than the friction surface between the outside of the locking ring 34 and the inner wall 10 of the syringe barrel 2, so the spring together with the piston 8 and the piston rod 6 become fixed relative to that caused by the spreading effect caused by the spring 45 move set circlip 34 and it is thus »ensured with a high degree of certainty that the tamper-evident device 27 or the spring element 28 with its extensions 32 emerges from the circlip 34 and comes to rest directly against the inner wall 10. The effect of the tamper-evident device 27 then corresponds to that as has already been described with reference to FIGS. 5 and 6, in order to avoid repetition, reference is made. Of course, this spring 45 can also be used in the injection device according to FIGS. 1 to 3.

Another embodiment of a securing ring 49 is shown in FIG. 9, which can be used, for example, in connection with a triggering device 9 according to FIG. However, the securing ring 49 differs from the embodiment shown in FIGS. 1 to 3 in that the support arms 19, which are connected to the piston rod 6, bear against a conical inner surface 50 of the securing ring 49, _{which is shown in} FIG Tapered towards the outlet 5. Also are the inner wall 10 of the syringe barrel 2 assigned claws 51 or friction-increasing extensions. If the piston rod 6 is now moved in the direction of the outlets 5 in order to squeeze out the medication 23, when the support arms 19 move along the conical inner surface 50, the securing ring is expanded or spread in the direction of the inner wall 10 of the syringe barrel 2, so that the claws 51 can fix in the inner wall to ensure that this can not move with the piston rod 6. If the support arms 19 have overcome the narrowest point of the conical inner surface 50, the coupling elements 17 formed by snap arms can move radially freely and the desired protective effect is provided against double use of the injection device 1, as is shown in the exemplary embodiment according to FIG .1 to 3 was written, a.

Finally, it should be pointed out that the individual exemplary embodiments can each form independent solutions according to the invention and also the tamper-evident device 27 alone without a trigger device 9 or with any other trigger device or the trigger devices 9 each without the tamper-evident device 27 can also form independent solutions according to the invention, with which the advantages according to the invention can be achieved.

Furthermore, it is shown in FIG. 5 that, using the tamper-evident device 27 and the spring element 28, a coupling device 7 between the piston 8 and the piston rod 6 can also be achieved at the same time if these mutually guided parts are penetrated with radially extending bores 52, 53 engage in the coupling pins 54 connected to the spring elements 2Θ. If the piston 8 moves when the piston 8 moves in the direction of the arrow 39 Pushed 38 out of the retaining ring 34, the spring element 28 snaps outward and thus simultaneously pulls the coupling pins 54 out of the bores 52 in the piston rod 6, so that when a force exerted on the piston rod is directed against the arrow 39, the force Piston rod 6 is pulled out of the piston and thus a

I further medication 23 with the piston 8 can no longer be sucked up.

In the standard disposable syringes, the syringe barrel is usually made of polypropylene while the plunger is made of polyethylene. The embodiment according to FIGS. 5 to 7 is advantageously suitable for syringes constructed in this way. The piston made of polyethylene cannot seal the surface damage formed by the tamper-evident device 27, so that the injection device is unusable. For the execution with rubber pistons, however, the embodiments according to FIGS. 1 and 2 are advantageous.

Another embodiment variant of an injection device 1 according to the invention is shown in FIGS. However, since the basic structure of the injection device 1 is the same, the same reference symbols are used for the same parts as in the figures described above. The injection device 1 again consists of a syringe cylinder 2, an outlet 5 and a piston 8 which is movable in the interior of the syringe cylinder 2 and which is coupled to the piston rod 6, for example via a coupling device 7. In the area of the piston 8

Piston rod 6 is again provided with a triggering device 9. This triggering device is formed by a, set over a An¬ 14 by the piston 8 distanced coupling element 15, a bead-like thickening eispielsweise _b and, with the Piston rod 6 connected coupling elements 17, which protrude from it in the direction of the piston 8 and are elastically deformable in the radial direction. The coupling elements 15 and 17 are fixed in their engaged position by a release device 9 designed as a locking ring 18. The locking ring 18 is arranged between the support arms 19 and the inner wall 10 of the syringe barrel 2.

A control edge 102 is arranged on the support arms 19 at a distance 100 measured axially parallel from a contact surface 101 on the piston 8. A free space 24 is formed from the contact surface 101 in the direction of the piston rod 6 and the support arms 19 in the direction of the inner wall 10 of the syringe barrel 2. In this free space 24, the securing ring 18 is arranged, which has an inner diameter 103 which is larger than a diameter 104 of an enveloping circle comprising the support arms 19. Compared to the inner wall 10 of the syringe barrel 2, the locking ring 18 is difficult to move. The support arms 19 form control strips or control surfaces 105, which are arranged concentrically to the central axis 25, relative to the locking ring 18 over the distance 100. The cross-sectional area of the free space 24 of the control edge 102 is enlarged in the direction of the piston rod 6 and the central axis. In this area, a diameter 106 of the coupling elements 17 umschrei¬ reproduced circle smaller than the inner diameter 103 of the retaining ring 18, reduced by at least twice the _Ov erdeckungsbreite 21 of the coupling elements 15,17. A length 107 of the free space 24 is greater than the distance 100, zuzüg¬ Lich a length 108 of the retaining ring 18. Advantageously, ann _k but also the length 107 of the free space 24 nor a Ü he _b _d eckungslänge 109 of the coupling device 7 is increased. be trained. By being at a distance 100 from the Contact surface 101 arranged control edge 102, a lifting height 110 is fixed, up to which the triggering device 9 is not effective. If the injection device 1 is now prepared for dispensing a medication 23, as can be seen better in FIG. 6, by moving the piston 8 in the direction of the outlet 5 by a lifting height 110, for example air 111 drawn in from the injection device 1 be removed. If the lifting height 110 is chosen to be smaller than the distance 100, the triggering device 9 does not take effect and it is thus possible, after the injection needle 4 has been set by moving the piston 8 in the direction of the arrow 112 around the lifting height 110, to perform an aspiration process, which ultimately occurs with everyone Injection should be carried out. If, subsequently, as already described in FIG. 1, the piston 8 is moved by more than the distance 100 in the opposite direction to the arrow 112 for the application of the medicament 23, the securing ring 18 is received by the free space 24, as corresponds to the dash-dotted line . This allows the radially elastic support arms 19 to spring open and the coupling element 15 arranged on the piston 8 is released. The piston 8 with the support arms 19 which are supported on the front-side contact surface 101 can thus only be moved in the direction of the outlet 5. The piston 8 can no longer be taken along in the direction of the arrow 112, which effectively prevents the injection device from being refilled. The change in volume required for expelling air 111 and for sucking in blood, for example, for performing the aspiration can be determined by the appropriate choice of distance 100 for control edge 102. For example, the suction volume can be adapted exactly to the volume of the needle channel 113 and that of the outlet opening 114. When using a clear material for the syringe barrel 2 The processes can already be observed from the needle opening 115 facing the piston 8, as a result of which the lifting height 110 can also be kept small.

A further variant of a coupling device 7 is shown in FIG. The same reference numerals are used again for components already shown in FIGS. 1 to 11. A coupling element 15 is arranged on the piston 8 via an extension 14. This coupling element 15, e.g. formed by a bead-shaped thickening, an approximately identical coupling element 116, which is connected to the piston rod 6, is assigned. The coupling elements 15, 116 are surrounded by half-shell-shaped connecting elements 117, an outer diameter 118 of the connecting elements 117 being slightly smaller than an inner diameter of the securing ring 18 concentrically encompassing the connecting elements 117. The outer diameter of the securing ring 18 is thus chosen that a relative movement between syringe barrel 2 and circlip 18 difficult due to higher pressing force or friction force, but between t circlip 18 and connecting element 117 by choice of

Diameter, as described above, is easy. As a result, when the piston rod 6 moves axially in the direction of an arrow 119, the relative movement between the connecting element 117 and the securing ring 18 disengages the latter after a stroke 120 has been covered, as a result of which the divided connecting elements 117 are lost due to the outer circumference being omitted by the Lock ring 18 fall off and release the coupling elements 15, 116. In this embodiment too, the choice of the axially parallel lengths of the securing ring 18 and the connecting elements 117 makes it possible to precisely predetermine the volume change possible by means of a piston movement until a decoupling process occurs. Therefore, this embodiment is also suitable for the venting of the syringe to be carried out on the occasion of the administration of a medicament or a solution by injection, as well as for a possibly required aspiration.

As is also indicated schematically in FIG. 11, knobs 121 projecting over the inner wall 10 of the syringe cylinder 2 can limit the movement of the piston 8 via the securing ring 18. These knobs 121 can, as is currently the case with commercially available disposable syringes, be formed by deformations of the syringe cylinder, which also prevented the plunger from falling out.

Otherwise, the control bar or the control surface 105 does not have to extend over the entire length of the distance 100 of the coupling element 17 or support arm 19, but can, as is schematically indicated in FIG. 6 by dashed lines, only by lugs 122 extending over part of the distance 100 may be formed.

Furthermore, it is shown in FIG. 11 that the lifting height 1.10 in the present exemplary embodiment was set to this extent for the sake of clarity, but it could, for example, have a maximum size delimited by a dash-dotted line 123. A radial movement of the coupling elements of the support arms 19 by the locking ring 18 would still be prevented even with a movement extending up to the line 123 and acting in the direction of the arrow 112, and thus a movement of the piston 8 in the direction of the arrow 112 would be possible .

In Figure 13 an alternative embodiment is a tamper-preventing apparatus shown after the invention ausgebil¬ _d eten injection device 1 two hundred and first The injection device tion, as in the previously described exemplary embodiments, consists of a syringe cylinder 2, an outlet 5, a piston 8 arranged in the syringe cylinder 2, which separates a cylinder chamber 11 for receiving a solution 221 from a cylinder chamber 13. The piston 8 is provided with a guide projection 239, which has a projection 241 separated by a groove-shaped recess 240. This projection 241 engages around latching arms 242, which are formed on the piston rod 6 or are connected to it, and in doing so snap into the recess 240 with locking lugs 243. In addition, the locking lugs 243 are provided with conically widening support surfaces against the piston 8, which are supported on a support surface 244 widening conically against the piston 8 by the groove-shaped recess 240. While part of this conical support surface, which can for example run at a cone angle 245 of approximately 45 degrees, is formed by the groove-shaped recess 240, while a further support surface part 246 is arranged on an expansion ring 247. In principle, this support surface 244 forms an inclined plane along which the locking arms 242 slide outward when the piston rod 6 is subjected to a force in a direction indicated by the arrow 248 in a position indicated by dashed lines. Depending on the size of the cone angle 245, a smaller or larger force component is exerted on the piston 8 in the direction of the arrow 24Θ, through which a certain solution 221 can be discharged through the outlet 5, as is the case for venting the Injection device '1 or when aspirating is necessary. As long as the locking arms 242 do not overlap a bead 249 of the expansion ring 247 and do not engage in a recess 250 located between the bead 249 and the rear side 231 of the piston 8, the piston 8 can still counteract by the action of the piston rod 6 withdraw the arrow 248. However, to get the solution 221 out of the cylinder chamber 11 through the To have to press out outlet 5, such a high force must be exerted that the locking arms 242 or their locking lugs 243 snap into the recess 250. Characterized in that, as shown by dash-dotted lines, the locking arms 242 then directly on the back 231 of

Support piston 8 ^' , this can be moved freely in the direction of arrow 248 relative to the syringe barrel 2. If, however, the user of such an injection device 1 tries to use the piston 8 a second time to draw up another solution 221, he pulls the locking arms 242, which are locked in the expansion ring 247, with the expansion ring from the piston 8 via the piston rod 6 from. For this purpose, the expansion ring 247, as also shown in the drawing, is guided with sufficient radial play on the guide projection 239, so that any adhesive force that may be present between the expansion ring 247 and the guide projection 239 is not sufficient to retract the piston 8 against the direction of the arrow 248 and at the same time to apply such a high force that a solution 221 can be sucked up.

FIG. 14 also shows an injection device 1 according to the invention, which comprises a syringe cylinder 2 and a piston 8, which divides the syringe cylinder 2 into two cylinder chambers 11 and 13. In order to prevent the injection device 1 from being used several times without authorization, there is a projection on the rear side 231 of the piston 8

241 arranged, which is held by a guide projection 239 at a distance 251 from the rear 231 of the piston 8. This projection 241 is overlapped by locking arms 242, which engage behind the projection 241 with locking lugs 243. On the projection 241, on the side facing away from the piston 8, a spreading core 252 is supported, which is inside the latching arms

242 is arranged and is designed as a cone. The latching arms run in the one adjoining the projection 241 part extending in the direction of the piston rod 6 over a length which corresponds at least to the distance 251, parallel to the longitudinal axis 202 of the syringe barrel 2. An incline of the conical end of the expanding core 252 is selected such that there is a relative adjustment between the locking arms 242 and the expansion core 252 by a distance 253 which is at least slightly smaller than the distance 251, the latching arms 242 are pivoted apart in the radial direction by an expansion path 254 which has at least one overlap width 255 between the locking lugs 243 and the projection 241 corresponds.

Furthermore, at a distance 253 from the base of the cone forming the expansion core 252, a locking lug 256 protruding in the direction of the cone is arranged.

If a solution 221 is now sucked in by the injection device, the piston can be withdrawn via the locking lugs 243 of the latching arms 242 against an extrusion direction shown by an arrow 248. If, now, the solution to be pressed 221 out of the cylinder chamber 11 through the outlet 5, so the piston rod 6 in the direction ^"of the outlet 5, ie in the direction of the arrow 248 is moved. This comes at the beginning of the movement of the piston rod 6 to a Relativbewe- between the latching arms 242 and the piston 8, a smaller portion of the force applied in the direction of the arrow 248 being transmitted as a feed force to the piston 8 corresponding to a cone angle 245 at a small cone angle and a larger portion at a larger cone angle, where This forward movement makes it possible to discharge a corresponding amount of the solution 221 through the outlet 5 to vent the injection device 1. If the piston 8 is now for example If a short piece of aspiration is withdrawn, this can be done as long as the piston rod 6 has not moved by the distance 253 relative to the piston 8 and the cone of the expanding core 252 has engaged in the latching lugs 256. If, on the other hand, the full feed force in the direction of arrow 248 is required, for example to press the solution 221 out of the cylinder chamber 11 into a human body, the feed force caused by the expanding core 252 in the direction of the longitudinal axis 202 is not sufficient, so that the locking arms 242 are pushed ever closer to the rear 231 of the piston 8 until the expanding core 252 engages in the latching lugs 256 and thus the latching arms 242 arrive in the position shown in broken lines. Thus, the locking lugs 243 are no longer in engagement with the projection 241, and from this moment the piston 8 can only be supported by the locking lugs 243 of the locking arms 242 being supported directly on the rear side 231 of the piston 8 in the direction of the Outlet 5 are moved. If, on the other hand, an attempt is made to pull the plunger back in the direction of the arrow 248 and, for example, to pull up another medicament or another solution, the locking arms 242 with the locking lugs 243 are moved back between the projection 241 and the syringe barrel 2 without the plunger 8 is taken along. Since the injection devices 1 of this type, as shown in FIGS. 11 and 12, require the dismantling of the individual parts and the subsequent assembly of correspondingly complex assembly devices in order to get a functional injection device 1 again and immediate reuse is not possible under any circumstances Sufficient security appears to be eliminated by multiple use and thereby a corresponding infection of patients treated immediately in succession with the same injection device. An injection device 1 is shown in FIG. 15, which consists of a syringe cylinder 2 and an injection needle 4 connected to it via a coupling arrangement 3. The coupling arrangement 3 is arranged on a tubular outlet 5 of the syringe barrel 2. In the interior of the syringe cylinder 2, a piston rod 6 is arranged so as to be displaceable in the longitudinal direction thereof and is connected in motion to a piston 8 via a coupling device 7. An unlocking or triggering device 9 is assigned to the clutch device 7. The piston 8 can consist of a rubber or plastic part or a corresponding plastic insert, on the circumference of which sealing elements, such as O-rings or rubber sleeves or the like, are arranged. With this plunger 8 or the rubber sleeves or O-rings, the plunger 8 lies against an inner wall 10 of the syringe barrel 2 and divides it into a cylinder chamber 11 connected to the outlet 5 and an opening 12 of the syringe barrel 2 associated cylinder chamber 13.

The piston 8 is essentially a tubular component, which forms a piston surface 314 at its end facing the outlet 5. An approximately bead-shaped guide extension 315 is arranged on its end opposite the piston surface 314. The coupling device 7 of a tamper-evident device 317 is arranged in the recess 316 formed by the tubular component. At the end of the piston rod 6 facing the piston 8, in the direction of the piston 8 and approximately parallel to a longitudinal axis 318 of the syringe barrel 2, there are approximately finger-like coupling elements 319 with ends 320 formed by a thickening, which are arranged at their ends in the direction of _the piston rod 6 against another coupling element 321 connected to the piston, namely an annular support surface 322 narrowing the recess 316 of the piston 8. support. The lugs 320 of the coupling elements 319 form in the direction of the longitudinal axis 318 and approximately parallel to them arranged contact surfaces 323 for an approximately cylindrical actuator 324. The lugs 320 with the lugs 320 in the recess 316 of the piston 8 are longitudinally movable in the direction the longitudinal axis 318 slidably mounted.

A range of motion 325 in which the piston rod 6 can move relative to the piston 8 is through an end wall 326 of the piston 8 in one direction and in the opposite direction, that is to say toward the opening 12 of the syringe barrel 2, through which the support surfaces 322 the coupling elements 321 limited. The piston rod 6 can thus move a distance 327 from the position shown in full lines to the position shown in broken lines.

An actuating element 328 counteracts the common forward movement of the coupling elements with the actuator 324 arranged between their contact surfaces 323. This actuating member 328 forms the unlocking or triggering device 9 and is arranged in the recess 316 and connected in one piece to the piston 8. The actuator 328 is approximately frustoconical and aligned concentrically to the longitudinal axis 318 and extends from the end wall 326 of the piston 8 in the direction of the actuator 324.

The actuator 324 ensures that the coupling elements 319 overlap with the coupling element 321 in a use position in which the lugs 320 engage the coupling element 321, the support surface 322 of the piston 8. This will prevent that with a zie Zurück¬ _h s of the piston 8 from the solid lines to the position indicated in broken lines position, the piston 8 with the piston rod 6 is taken. As a result, when the injection device 1 is pulled open, medicament can be drawn in from a container via the injection needle 4.

If, after the medication has been drawn up, the piston rod 6 is moved in the direction of an arrow 329, this movement is countered by the pressure required to press out the medicament contained in the interior of the cylinder chamber 11 through the injection needle. This pressure is higher than the frictional resistances between the piston 8 and the piston rod 6 or the lugs 320, as a result of which the piston rod 6 moves forward relative to the piston 8. After a short displacement movement, this now results in the actuator 324 hitting the actuating member 328 and no longer being able to move forward in the direction of the injection needle 4 or the end wall 326 of the piston 8, while the coupling elements 319 continue to move forward can move to the dashed position. There they are supported with their end faces 330 on the end wall 326, as a result of which a correspondingly high compressive force can be exerted, so that the medicament 23 can be pressed out of the cylinder chamber 11 against the resistance of the medicament when it passes through the injection needle 4. During the forward movement of the coupling elements 319 via the path which is moved forward the length of the actuating element 328 by which it projects from the end wall 326 in the direction of the piston rod 6, the actuator 324 is removed from the area of the contact surface 323 of the lugs 320 is moved into a space 331 arranged between the coupling elements of this contact surface 323.

To carry out this relative movement between the piston 8 and the coupling elements 319, the recess 316 of the piston 8 has a depth 332 which is equal to or greater than that Sum of a length 333 of the contact surface 323 of the coupling elements 319 and a height 334 of the actuating element 328. Furthermore, a width 335 of the actuating element 328 is smaller than a distance 336 between the lugs 320 in their rest position and a distance 337 of the clearance space 331 larger than a diameter 338 of the actuator 324.

As can be seen from FIG. 16, the radially adjustable coupling elements 319 can thereby reach a rest position, in which they are located within a conical envelope surface that tapers in the direction of the end wall 326 of the piston B. The fact that an outer width 339 between the lugs 320 of the coupling elements 319 which are in the rest position is smaller than a width 340 of an opening 341 of the piston 8 means αip lugs 320 and the support surface 322 in this position. As a result, the drive connection between the piston rod 6 and piston 8 is interrupted in a direction opposite the arrow 329, as a result of which a new suction of a medicament via the injection needle 4 and the opening into the cylinder chamber 11 is effectively prevented and therefore this injection device 1 is only for is single use. This can reduce the dangers that can arise from multiple use of an injection device, such as e.g. Infectious diseases, AIDS, etc., especially where such an injection device has been used several times for reasons of efficiency, can be effectively prevented.

In Figure 17 is to the actuator 324 in position between the de-- Kuoplungsele ducks 319 dargest- Mt. The actuator 324 is ': where au- integrally a substantially cylindrical body having ^• terschiedlichen diameters formed, wherein a the' 328 tätigungsglied opposite diameter 342 is larger and a transition 343 to a smaller diameter range is formed by a truncated cone. The surface area with the diameter 342 forms an expansion surface 344 for the contact surface 323 of the coupling elements 319. The contact surface 323 has extensions 345 associated with the transition 343, which protrude beyond the contact surface 323 in the direction of the longitudinal axis 318. With this design, a force acting on the actuator 324 from the actuator 328 in the direction of an arrow 346 is opposed by a resistance which can be determined by the shape of the transition 343. This makes it possible to influence the time at which the tamper-evident device 317 is triggered by constructive measures, as a result of which it is also possible to aspirate with such an injection device 1.

This design of the actuator 324 and the increased resistance which has to be overcome in order to release the movement of the coupling elements or to decouple or push out the actuator 324 prevent the piston rod 6 from getting in Rich in the event of an inadvertent incorrect movement ¬ device of the injection needle 4 before the medication is pulled out the decoupling process takes place and thus the injection device 1 is unusable.

FIG. 18 shows an actuator 324 with a locking pin 347, which acts in the direction of the longitudinal axis 318 and which acts as a spacer element 348, which is arranged on the end of the actuator 324 opposite the actuator 328. This locking pin 347 supports the actuator 324 against a force, corresponding to the arrow 346 in the direction of the piston rod 6. When a certain force is exceeded, the locking pin 347 is kinked, as a result of which the actuator 324 can be pressed into the position shown in dashed lines and thus, as already shown that of Figure 2, the coupling device 7 solved. Through the choice of the material and the dimension of the locking pin 347, a desired resistance value against the triggering of the clutch device 7 can also be selected in this embodiment. The locking pin 347 can be integrally connected to the actuator 324, for example molded, as is also possible to glue, weld or inject it on the end face. To achieve a suitable kink resistance, it is of course also possible to manufacture the locking pin 347 from a wide variety of materials.

FIG. 19 shows a further embodiment variant of the actuator 324, in which the spacer element 348 is shown by a spring arrangement 349, which is arranged in the free space 331 between the coupling elements 319. The spring arrangement 349 is formed from at least two spring elements 350 which are connected to the piston rod 6 in terms of movement. The spring elements 350 extend approximately at an angle between 30 degrees and 50 degrees, preferably 45 degrees, from the longitudinal axis 318 in the direction of the piston 8 and are arranged within a slot 351 of the coupling elements 319. The protruding end of the spring element 350 has a joint arrangement 352 in which a push rod 353 is mounted. This connects the spring element 350 with an extension 354 of the actuator 324 to a swivel bearing 355 arranged at the front end of the extension 354. This arrangement forms a so-called over-center lock which, due to the action of the spring elements 350, causes the actuator 324 to move Direction of arrow 356 provides resistance. If the pivot bearing exceeds a connecting line 357 in the direction of the piston rod 6 due to the action of the actuator 328 during a relative movement between the piston rod 6 and the piston 8, the effect of the spring elements 350 will Actuator brought into the end position shown in dashed lines, whereby the coupling elements 319 come to a rest position in which the lugs 320 release the support surfaces 322 of the piston 8 and thus the drive connection between the piston rod 6 and the piston 8 is interrupted.

20 and 21 show further design variants of the spacer elements 348 for the actuators 324. So it is e.g. possible to achieve a corresponding deformation path wavy or in the form of a

Form expansion element 35B. Furthermore, it is possible to provide these spacing elements 34Θ with weakening cross sections 359 in order to influence the buckling behavior and thus to determine the desired resistance to a deformation force in the direction of arrow 356.

Another embodiment variant for the coupling device 7 is shown in FIGS. 22 and 23. The piston B has an approximately cylindrical recess 316 with a diameter 360 that is larger than a diameter 361 of one

Opening 362 of the piston 8. The region of the recess 316 which is arranged opposite the opening 362 is provided with a truncated cone-shaped constriction. Due to the different diameters 360, 361, the annular support surface 322, which is arranged approximately perpendicular to the longitudinal axis 318, is formed for the projections 320 of the coupling elements 319 connected to the piston rod 6 and projecting in the direction of the piston 8. The end region of the coupling elements 319 has a bevel, which, in cooperation with the frustoconically narrowing recess 316 of the piston 8, causes a movement of the end regions of the coupling elements 319 and thus of the lugs 320 with a relative movement between the piston and the piston rod 6 . On the opposite inner surfaces 363, the coupling tion elements 319 a locking device 364, which is formed by oppositely arranged hook-shaped extensions 365.

As can now be seen better from FIG. 23, the latching device 364 is brought into engagement after a stroke 366 has been covered and the coupling elements 319 are positioned in a position in which a width 367 of the lugs 320 is smaller than the diameter 361 of the opening 362 of the piston 8. Thus, the clutch device 7 ^f disengaged and moving the piston 8 by means of the piston rod 6 in the direction of P eiles 356 no longer possible. As a result, the injection device 1 can no longer be refilled with a medicament and thus effective protection against reuse of such an injection device 1 is provided.

FIG. 24 shows that, according to the invention, the clutch device 7 can also be formed by the clutch elements 319 being arranged on the piston 8. The piston rod 6 has the support surface 322 forming the coupling element 321 for the lugs 320 of the coupling elements 319. The active position of the coupling elements is achieved by the actuator 324 arranged between the coupling elements 319. The actuating element 328 protruding in the direction of the actuator 324 is arranged on an end face 369 of a recess 370 of the piston rod 6 facing the piston B. By a relative movement between the piston 8 and the piston rod 6 when ejecting the Injektionsvor- device 1, the actuator 324 is moved be¬ from the actuator 328 in a space 371 between the coupling elements 319, whereby they by their radial adjustability in i _rs in dashed lines shown rest position, _b ei the clutch device 7 is released and the width 367 between the lugs 320 of the coupling elements 319 is smaller than an opening width 372 of the piston rod 6. As a result, effective protection against refilling of the injection device 1 is achieved even in this embodiment variant and reuse is prevented.

In principle, it should be noted that in all of the exemplary embodiments shown, the parts fastened to the piston rod can optionally be exchanged for the parts fastened to the piston.

While in the previous exemplary embodiments the coupling elements usually overlap one another in regions in order to enable locking or entrainment of the individual parts, it is also possible, among other things, to provide the mutually facing surfaces of the coupling elements with a high To provide a surface with a coefficient of friction and only to brace it against one another, so that the frictional force is sufficient to take the plunger with the injection needle 4 when the medicament is drawn up.

In the case of the opposite movement, that is to say when the medicament is squeezed out, however, the resistance would then not be sufficient or the friction surface would widen in the direction of the piston 8, so that the piston rod 6 can move relative to the piston 8 and through the unlocking device described above lines of the piston 8 is released from the piston rod 6.

An advantage of the previously described embodiments of the injection device designed according to the invention is that the material fatigue does not adversely affect the safe function for uncoupling the piston, even when the injection devices 1 are stored for a longer period of time. bens 8 can affect the piston rod 6. It is particularly advantageous here if the pretensioning of the coupling elements, which enables the coupling elements 319, 321 to be decoupled by changing their distance from one another or the envelope circle diameter enclosing them, are made of plastic, so that after removing the actuator ¬ member 324 these return to their smaller dimensions and thus can emerge from the coupling element 321 enclosing them.

In order to ensure a safe unlocking when the actuator 324 is pushed out, it is also possible to connect the transition surfaces to the projections 320 or the support surface 322 with roundings or inclined surfaces, so that after the actuator is released 324 when exercising one

Pulling force on the piston rod 6, the coupling elements 319 are pressed together in the direction of the longitudinal axis 318 of the syringe cylinder 2 and thus a decoupling from the piston 8 and the piston rod 6 is achieved.

In Figure 25 is with the cylinder 401 of a disposable syringe be¬ lines, in which a piston 402 is found ^* ührt, wherein the end face 403 sealingly engages the inner surface of the cylinder four hundred and first Guide ribs 404 are also indicated for guiding the piston. The cylinder 401 has a syringe cone 405, on which a cannula can be attached before the syringe is used.

The piston "402 has on its end face 403 a projecting to the syringe cone 405 latch part 406 on whose greatest external diameter a larger than the smallest inner diameter b in the interior of the syringe cone 405. For locking the locking member in the syringe cone 405 on En _d e _d it Spritzenhubes is the locking part 406 remote, as indicated by 407. When the piston 402 is displaced into its end position, the shoulder 407 interacts with a stop 40B which is arranged on the inner surface of the syringe cone 405 and defines the smallest inside diameter of the same, so that after a movement of the piston 402 into the end position of the syringe stroke Locking of the locking part 406 by the interaction of the shoulders or stops 407 and 408 takes place as shown in FIG.

For proper disposal of the cannula after use of the disposable syringe, as shown in more detail in FIGS. 27 and 29, the syringe cone has a predetermined breaking point in the area facing the cylinder 401, which is formed by a circumferential groove 409. Above this predetermined breaking point, the spike cone 405 carries drivers 410, which can be formed in a particularly simple manner by an external toothing. The locking part 406 is designed as a pin which can be inserted into the piston end face, so that after the locking part 406 has been locked in the syringe cone 405, thereby preventing further use of the syringe by preventing it from being opened again, the piston 402 is released from the locking member can and is used for disposal of the cannula 411 used. For this purpose, an internal toothing 413 provided in the grip area 412 of the piston 402 interacts with the toothing or the drivers 410 on the syringe cone, so that after the catches 410 or inner toothing 413 are snapped in, the syringe cone is rotated when the piston 402 is turned In the area of its predetermined breaking point, for example a circumferential groove 409 breaks, and the remnants of the syringe cone 405, together with the cannula 411, are safely held inside the piston 402. The two separate components of the disposable syringe, namely the cylinder 401 and the piston 402 with the cannula 411 accommodated in its interior are therefore unsuitable for further use, as is clearly shown in FIGS. 4 and 5.

In the embodiment shown in FIG. 30, the same reference numerals have again been used for the same components. The piston 402 in turn has a locking part 406 in the region of its end face 403, which is locked by stops 408 at the end of the syringe stroke with stops 408 on the syringe cone. For a correspondingly easy passage, the locking member has axially extending slots 414. The locking member 406 is in turn designed to be detachable from the piston 402, with carriers formed by a toothing 415 being provided for securing the bearing. In order to prevent erroneous locking of the locking part 406 in the syringe cone 405 before pulling on a pharmaceutical agent, elastically deformable and axially projecting stops 416 are provided on the end face 403, which stop before the further pulling up of the Oppose piston 402 in the setting for slight resistance. When the pharmaceutical agent is applied, however, this resistance can easily be overcome in order to discharge the entire and desired amount of the pharmaceutical agent, whereupon when the end face 403 is in contact with the end face of the cylinder, a locking mechanism via the interacting stops or Paragraphs 407 and 408 take place.

After removal of the plunger after use of the syringe, in contrast to the embodiment shown in FIGS. 27 and 29, the opening in the plunger intended for receiving the locking part 406 and the one for securing the position of the locking part 406 can now be provided. αese _h enes driver 410 for disposal of the cannula 411 be pulled up. For this purpose, the end face 403 is guided over the cannula 411 until the drivers 410 on the syringe cone 405 engage with the drivers 410 in the region of the end face 403 and the syringe cone 405 after twisting the piston together with the cannula 411 after tearing the syringe cone 405 is received in the area of its predetermined breaking point inside the piston 402. By locking the locking part 406 in the syringe cone 405 and also by partially separating the syringe cone 405 together with the cannula, it is no longer possible to reuse the syringe.

31 to 33 show an embodiment variant of the injection device 1 according to the invention, which in turn has a syringe cylinder 2, an injection needle 3 and a coupling arrangement 3 for connecting the injection needle 3 to the syringe cylinder 2. A piston 8 is arranged in the interior of the syringe cylinder 2 and is coupled to the piston rod 6 via a coupling device 7. The piston rod 6 comprises a central part 420 which has, for example, a circular cross section and from which guide flanges 421 project in the radial direction at 90 degrees.

Coupling elements 319 designed as latching arms 423 protrude from an end face 422 of the piston rod 6 facing the piston. Usually, two or more coupling elements 319 distributed around the circumference and separated by slots are arranged. The coupling elements 319 are provided with a shoulder 320, which is provided with locking lugs 424 projecting outwards in the circumferential direction and on the opposite inside with an internal thread 425. The locking lugs 424 have support surfaces 322 which are supported on projections 426, which form coupling elements 321 and are fixedly connected to the piston 8. The projections 426 protrude over the surface of a recess 427 in the direction of the latching arms 423. Ijie approaches 320 are biased towards the surface of the recess 427 by a tension member 428, so that the detents 424 and the projections 426 overlap. The tensioning member 428 protrudes in the direction of an end face 429 of the piston 8 and is supported on an actuating member 328 extending from the end face 429 in the direction of the piston rod 6. The actuating member 328 and the tensioning member 428 form the triggering device 9. The tensioning member 428 is provided on its surface with an external thread 430. This external thread is designed as a steep thread. The internal thread 425 and the external thread 430 belong to the same thread type, so that the tensioning member 428 is adjustably mounted in the internal thread 425.

If the piston 8 with the piston rod 6 is now moved away from the injection needle 3 in order to draw up a liquid or a liquid medication therethrough, the piston 8 is moved by the latching lugs 424 which engage with the projections 426 Movement of the piston rod 6 entrained.

If the absorbed liquid or medication is to be squeezed out, the piston rod 6 must be moved in the direction of an arrow 431. The feed force in the direction of arrow 431 is transmitted from the piston rod 6 to the piston 8 by the tensioning member 428 to the actuating member 328 of the piston 8. The compressive force exerted on the piston via the piston rod 6 now causes the tensioning member 428 to move about a central longitudinal axis 432 owing to the steep thread which is used for the external thread 430 starts to turn. This leads to the fact that the tensioning member 428 moves back from the position shown in FIG. 31 to the position shown in FIG. 33, a perfect drive connection both in the direction of arrow 431 and over this entire path covered during this exertion of the pressure force given in an opposite direction. This now means that the piston 433 shown in FIG. 33 also allows the piston to be withdrawn at any time counter to the direction of advance of the arrow 431. This lifting height 433 can thus be used for aspiration. This process of aspiration is important after the injection needle has been inserted into a body for the administration of a medicament in order to determine whether or not the person administering the liquid medication has hit a blood vessel. This is determined by applying a small amount of the liquid medication, whereupon the plunger is pulled back against the direction of arrow 431. If the person administering the medication has now hit a vein, for example, he pulls blood into the syringe barrel 2 when the plunger 8 is withdrawn. Because of the transparent design of the syringe barrel 2, the person administering the medication can therefore recognize this immediately.

Following the aspiration, the required amount of medication is then sprayed out, as a result of which a correspondingly high compressive force is required in order to move the piston 8 forward by means of the piston rod 6. This leads to a further rotation of the tensioning element 428 in the internal thread 425, whereupon this falls into a free space 331, as shown in FIG. 32. This will move towards the surface of the

Recess 427 directed bias of the locking arms 423 is lifted and the locking arms spring into the position shown in full lines in FIG. In this there is now a diameter 338 of an enveloping circle surrounding the projections 320 smaller than a width 340 of an enveloping circle encompassed by the projections 426, so that when the piston rod 6 moves counter to the direction indicated by the arrow 431, the piston rod 6 emerges from the recess 427 and the piston therefore no longer moves back in the direction of the piston rod 6 ¬ can be pulled.

This construction of the injection device 1 thus ensures that after the application of a quantity of medication which is greater than that quantity of medication required for aspiration, the action of the triggering device 9 means that the injection device 1 is released by the uncoupling of the piston 8 and the piston rod 6 is destroyed and the injection device can therefore no longer be used for a further injection process.

Of course, the choice of the lifting height 433, via which a positively actuated guiding of the tensioning member 428 in the latching arms 423 is achieved, makes it easy to determine that route and any amount of medication that can be used for aspiration.

Furthermore, the design of the latching arms 423, in particular their shape in order to achieve a pretension directed in the direction of the actuating member 328, can also be freely selected. It is thus possible to manufacture the piston, which in particular consists of a molded plastic part, with the directly integrally formed latching arms 423 in such a way that the latching arms assume the shape shown in FIG. 32, and in the position according to FIG .31 are held only by the expansion effect with the tendon 428. On the other hand, it is also possible to design the support surfaces 322 as a conical surface 8 widening in the direction of the piston 8, so that after the tension member 428 has been removed and the piston rod 6 has been withdrawn from the piston 8. out, the locking arms 423 are pressed together, and thus also a decoupling of the elements 319 and 321 forming the coupling device 7 takes place. In addition, any other embodiment known in the art that is suitable for this purpose is applicable. It is only essential that the drive connection between the piston rod 6 and the piston 8 is maintained over the desired lifting height 433 and then automatically released, so that a single use of the injection device 1 is ensured with a high degree of certainty.

34 to 37 show a further embodiment of an injection device 1, in which only a part of the syringe cylinder 2 is shown, the connection between the syringe cylinder 2 and the injection needle 3 corresponding to the exemplary embodiments described in the preceding figures or according to FIGS Designs from the prior art can be formed.

This embodiment is in principle similar to the embodiment shown in FIGS. 15 to 17, which is why the same reference numerals are used for the same parts. A piston guided in the syringe cylinder 2 is again arranged! which is connected to the piston 8 by means of a coupling device 7, in the embodiment described in detail in FIGS. 15 to 17. The coupling elements 319 and 321, which are designed as projections 426 or locking lugs 424, serve this purpose. To hold the coupling elements 319 in a position covering the coupling elements 321, the actuator 324 is provided, which is actuated by the actuator. tion member 328 forms a trigger device 9. The function of these Auslösevor¬ described with reference to Figure 15 to 17 will now device 9 by the arrangement of an additional Originalitätssich ^{'erungsvorrichtung} 435 over a certain forward feed size 436 turned off by itself the support arms 437

Support piston rod 6 directly on piston 8. These support arms 437 are each formed by parts of the guide flanges 421 of the piston rod 6 separated from a central web 439 by a slot 438. These support arms 437 are provided with projections 440 at a distance corresponding to the desired feed size 436 from the maximum filling position of the syringe barrel 2.

If the piston 8 with the piston rod 6 is now moved in the direction of the injection needle 3 by a smaller amount than the feed size 436, nothing changes in the position of the support arms 437 in relation to the piston 8. In this position, the piston 8 can therefore be pulled out of the syringe cylinder 2 at any time by moving the piston rod 6 back.

If, on the other hand, the piston rod 6 is pushed into the syringe cylinder 1 by an amount larger than the feed size 436, the support arms 437 are deformed in the direction of the longitudinal axis 318 after the projections 440 have entered the syringe cylinder 2, so that the support arms 437 are no longer on the Support the end face 441 of the piston 8 facing the piston rod 6, but instead enter the recess 434 within the coupling elements 321. However, this also moves the coupling elements 319 in the direction of the piston surface 314.

The actuator 328 pushes the actuator 324 into the free space 331 between the coupling elements 319, so that there is no longer any overlap between the lugs 320 and the support surfaces 322. This is an unlock tion between the piston rod 6 and the piston 8 reached. If the user now tries to pull the piston 8 out of the syringe cylinder 2 again with the piston rod 6 in order to draw up further medication, the coupling elements 319 emerge unhindered from the recess 434 and the piston rod releases from it without it to take the piston 8.

36 and 37, the piston rod 6 comprises four support arms 437, each offset by 90 degrees to one another in the circumferential direction, and the coupling elements 319 are also designed in the form of a segment of a circle and separated from one another by slots 442. The arrangement of the support arms 437 or coupling elements 319 distributed over the circumference prevents the various individual parts from being forced into the syringe barrel even when handled carelessly, thereby ensuring rapid and safe actuation of the injection device.

With the arrangement of the additional tamper-evident device 435, a feed size 436 for the aspiration can now be adapted in a simple manner by the arrangement of the projections 440 to different applications of the injection devices 1.

In addition, compared to the known injection devices currently in use, this injection device has only one single part, namely the actuator 324. The manufacturing costs are thus very low and the mass use of such an injection device, especially in the developing countries, is possible with a high level of security against repeated use. With the injection devices according to the invention described above in the various exemplary embodiments, it is advantageously possible to produce all individual parts from plastic. Only in the case of very small injection devices, for better sealing of the plunger 8 from the syringe barrel 2, is it advisable to arrange an O-ring made of rubber or the like for sealing purposes in the region of the plunger 8.

Of course, it is also possible that individual

Parts, such as the actuator 324 or the piston 8, can be made of a silicone rubber or optionally a stainless steel or the like. Likewise, it is also possible for the syringe barrel 2 to consist of both plastic and glass.

A further injection device 1 is shown in FIG. 38, which is essentially designed in accordance with the embodiment shown in FIGS. 34 to 37. The same reference numerals are therefore used for the same parts. The embodiment shown in FIG. 38 now differs from that shown in FIGS. 34 to 37 in that the actuation of the support arms 437 instead of the interaction of the projections 440 with the inside of the syringe barrel 2 is due to the interaction of the support arms 437 with one between the same and the inside of the syringe barrel arranged retaining ring 442.

For this purpose, the support arms 437 are provided with links 443, which are assigned to the locking ring 442 arranged between the support arms 437 and the syringe cylinder 2. This, for example, C-shaped locking ring 442 has an inner diameter 444 which is smaller than a diameter 445 of an enveloping circle surrounding the support arms 445. The ins special C-shaped locking ring is also preloaded in the radial direction or has a larger outside diameter than the inside diameter of the syringe barrel 2. As a result, it can only be displaced in the longitudinal direction of the syringe barrel 2 when considerable force is exerted. For this purpose, it can also be provided with corresponding roughening on the outside facing the syringe barrel 2. If the piston 8 is now pulled out of the syringe cylinder 2 via the piston rod 7 and thus the liquid, in particular the liquid medicament, is drawn into the syringe cylinder 2, this locking ring 442 is pulled along over the shoulders of the piston 8 facing the piston rod 6. If the piston rod 6 with the piston 8 adjoins it in the direction of the arrow 431, that is to say to squeeze out the liquid, the locking ring 442 remains in its position and the piston rods with their support arms 437 move relative to the locking ring in the direction of the injection needle 3. The piston rod 6 with the piston 8 can now be moved as desired in or against the direction of the arrow 431 via the lifting height 433, without decoupling between the piston 8 and the piston rod 6.

If this stroke height 433 is exceeded, the run-up surface 446 runs onto the locking ring 442 and the support arms 437 are deformed in the direction of a central longitudinal axis 432 of the syringe cylinder 2, as a result of which the piston rod 6 is displaced relative to the piston 8 and in the direction thereof can move and by means of the actuator 328, the actuator 324 between the coupling elements 319 is removed, whereupon the coupling device 7 and thus the drive connection between the piston rod 6 and the piston 8 is canceled for movements against the arrow 431. Finally, it should also be pointed out that various details of the injection devices described in the above exemplary embodiments can also be exchanged among one another and the individual exemplary embodiments or combinations of individual solution variants of the release device or tamper-evident device or the pistons 8 or piston rods 6 in each case can represent independent, independent solutions according to the invention.

In the embodiment shown in FIGS. 34 to 37, a length 447 of the stop 320 is shorter than a length 448 of a guide surface 449 of the locking arms 437. A height of the projections 440 is dimensioned such that it deforms the locking arms 437 by a pivoting angle 450, which leads to an inward adjustment of the locking arms 437 by an amount greater than an overlap width 451. Furthermore, for a reliable release of the coupling connection, it is advantageous if a distance 452 is greater than the length 448.

Claims

Patent claims

1. Injection device for single use with a syringe barrel, a piston guided in the syringe barrel and a piston rod connected to the latter, in particular via a coupling device, which preferably has a length which is greater than the length of the syringe barrel and with one on the Coupling arrangement provided on the side of the syringe cylinder facing away from the piston rod and via which an injection needle can be coupled to the syringe cylinder, characterized in that a triggering device (9) is provided for the piston (8) and / or the piston rod (6). and / or a tamper-evident device (27) is assigned.

2. Injection device according to claim 1, characterized in that the triggering device (9) and / or an originality 'securing device (27) is arranged on the side facing away from the coupling arrangement (3) for the injection needle (4).

3. Injection device according to claim 1 or 2, characterized ge indicates that the trigger device is formed by a particular one-piece locking ring which is loosely guided on the piston rod (6) and between the piston rod (6) and an inner wall (10) of the Syringe barrel (2) attached is arranged and is supported with an end face facing the injection needle (4) on the side of _the piston ⁽ 8 ⁾ and / or a driver (38) facing away from this and that the coupling device ⁽ 7 ^{) is arranged} approximately in the same cross-sectional area is like the circlip (18,34,49). »)

4. Injection device according to one or more of claims 1 to 3, characterized in that the piston rod (6) and / or the piston (8) in the region of the facing end with radially movable coupling elements (17) of a coupling device (7) and that a release device (9), in particular a C-shaped locking ring (18, 34, 49), is arranged between the radially adjustable coupling elements (17) and the inner wall of the syringe cylinder (2), a thickness of the locking ring (18, 34, 49) is greater than a distance (20) between the inner wall (10) of the syringe barrel (2) and the radially adjustable coupling elements (17) in their engagement position minus a coverage width (21) between the coupling elements (17) and the projection (16).

5. Injection device according to one or more of claims 1 to 4, characterized in that the safety ring (18, 34, 49) is designed to be radially resilient in the direction of the inner wall (10) of the syringe cylinder (2) .

6. Injection device according to one or more of arrival ^'- Messages 1 to 5, characterized in that the syringe barrel (2) facing outside of the backup ring (18,34,49) having a reibungserhohenden pad and / or clamping parts and / or clamping rings is provided.

7. Injection device according to one or more of claims 1 to 6, characterized in that the piston (8) has a cylindrical projection ⁽ 14 ⁾ which is directed in the direction of the piston rod (6) and which is turned away from the piston The end is provided with a circumferential bead forming a coupling element (15) and the piston rod (6) is provided with a plurality of snap arms which form the coupling elements (17) and are directed towards the piston (8) and which have projections (16) directed towards one another. are provided and the projections (16) of the piston rod (6) between the

Bead and the piston (8) are arranged and that the locking ring (18, 34, 49) is arranged in the free space between the snap arms and the inner wall (10) of the syringe barrel (2).

8. Injection device according to one or more of claims 1 to 7, characterized in that the coupling elements (17) of the piston rod (6) in the direction of the piston (8) with conically extending support surfaces to be tapered against the piston are provided and preferably the

Retaining ring (18, 34, 49) is provided with a conical bore which widens in the direction of the open end of the syringe barrel (2).

9. Injection device according to one or more of claims 1 to 8, characterized in that the piston rod (6) is provided with a driver (38) formed, for example, by an annular projection, the outer diameter of which is smaller than an inner wall (10) of the syringe cylinder (2) and that on the side facing the piston rod (6) a securing ring (34, 49) is arranged, which has projections projecting in the direction of the piston (8), which the driver (38 ) protrude in the direction of the piston (8) and a tamper-evident device (27), for example one in In the direction of the inner walls (10) of the syringe barrel (2), prestressed approximately V-shaped or U-shaped spring elements (28) are supported, which are held in the region of their base on the piston (8) or the piston rod (6).

10. Injection device according to one or more of claims 1 to 9, characterized in that the V- or U-shaped spring is provided with angled projections in the region of its leg ends and the end faces are equipped with cutting edges or claws.

11. Injection device according to one or more of claims 1 to 10, characterized in that the U- or V-shaped spring element (28) is mounted on the piston (8) in the region of the base and auf¬ in the region of its free legs Coupling pins (54) facing each other, which are inserted into radially extending bores (52, 53) penetrating the piston (8) and the piston rod (6) in the overlap region.

12. Injection device according to one or more of claims 1 to 11, characterized in that the securing ring of the triggering device on the side facing the piston is provided with a cone-like tapering surface against the injection needle, which is provided with smaller ones within an enveloping circle The diameter of the support members provided as the attachment surface cooperates, these support members preferably having contact surfaces that widen conically in the direction of the injection needle.

13. Injection device according to one or more of claims 1 to 12, characterized in that a cone angle of the surfaces or contact surfaces is approximately 4 degrees. -52-

14. Injection device according to one or more of claims 1 to 13, characterized in that the safety ring is C-shaped and the piston rod or the piston has a nose or spring which extends into the region of the inner wall of the syringe cylinder is provided, which has a width which is greater than a distance between the mutually facing end faces of the C-shaped locking ring in the relaxed state and preferably the mutually facing surfaces of the nose or spring and the end faces of the locking ring are designed with low friction.

15. Injection device according to one or more of claims 1 to 14, characterized in that a length of the nose or spring is greater than a minimum coupling path of the coupling device between the piston rod and the piston.

16. Injection device according to one or more of claims 1 to 15, characterized in that the coupling element (17) is provided with a control edge (102 *) which is parallel to the central axis of the piston rod (6) by a distance (100) is arranged by a contact surface (101) of the locking ring (18) facing the control edge (102), which corresponds to a stroke height (110) of the piston (8), in which a stroke volume is at least the volume of a needle channel (113) the injection needle (4) and possibly an outlet opening (114).

17. Injection device according to one or more of claims 1 to 15, characterized in that between the control edge (102) and the contact surface (101) a continuous control strip or control surface (105) on the coupling element (17) or support arm (19) is arranged.

18. Injection device according to one or more of claims 1 to 17, characterized in that the securing ring (18) parallel to the central axis (25) is one of the distance ⁽ 100) between the control edge ⁽ 102) and the contact surface (101). has a corresponding length and preferably a

The length of the control bar or control surface (105) is smaller than the distance (100).

19. Injection device according to one or more of claims 1 to 18, characterized in that a length of the control bar or the control surface (105) of the securing ring (18) extending parallel to the distance (100) is smaller than the distance (100).

20. Injection device according to one or more of claims 1 to 19, characterized in that a diameter (118) of an enveloping circle surrounding the control strip or control surface (105) or the coupling elements (17) or connecting elements (117) is smaller is as an inner diameter (103) of the locking ring (18).

21. Injection device according to one or more of claims 1 to 20, characterized in that the diameter (106) of the coupling elements (17) or the piston rod (6) in the region of the control edge (102) against the contact surface (101) extending part of the free space (24) surrounding enveloping circle by twice the overlap width (21) between the coupling elements (15, 17) is smaller than the inner diameter (103) of the retaining ring (18).

22. Injection device according to one or more of claims 1 to 21, characterized in that the free space (24), starting from the contact surface (101), has an axially parallel length (107) which is greater than the length ( 108) of the locking ring (18), plus the distance (100).

23. Injection device according to one or more of claims 1 to 22, characterized in that the free space (24), starting from the contact surface (101), has an axially parallel length (107) which is greater than the length ( 108) of the locking ring (18), plus an overlap length (109) of the coupling elements (15, 17).

24. Injection device according to one or more of claims 1 to 23, characterized in that the coupling device (7) is connected to the piston (8) or the piston rod (6) by projections (241) and to the piston ¬ rod (6) or the locking arms (242) connected to the piston (8), the locking arms (242) engaging behind the projection (241) by means of locking lugs (243) and that the projection (241) along the locking arms ( 242) is displaceable parallel to the longitudinal axis (202) of the syringe barrel (2) and a distance between the latching arms (242) narrows with increasing distance (253) from the projections (241).

25. Injection device according to one or more of claims 1 to 24, characterized in that between the projection (241) and the latching arms (242) an expanding core (252), which can be moved independently of these and serves as an opening member (215). is arranged.

26. Injection device according to one or more of claims 1 to 25, characterized in that the projections (241) are arranged at a distance (251) from the rear (231) of the piston (8) and on the projection (241) a support surface (244) for the latching arms (242), which widens conically in the direction of the rear, connects, a part of the support surface part (246) closer to the rear (231) of the piston (8). the supporting surface (244) is arranged on an expanding ring (247) which is adjustably mounted independently of it and which has a recess (250), in particular a groove or an undercut for the locking lugs (243) of the latching arms (242).

27. Injection device one or more of claims 1 to 26, characterized in that the coupling device

(7) with the piston (8) or the piston rod (6) has movement-connected coupling elements (319, 321) and an associated, relatively adjustable actuator (324) of the tamper-evident device (317) with which the coupling elements ( 319, 321) are held in engagement in a use position.

28. Injection device according to one or more of claims 1 to 27, characterized in that the piston rod (6) within one in the direction of the injection needle (4) through an end wall (326) of the piston (8) and in the opposite direction through the the piston (8) movement-related coupling elements (321) limited range of motion (325) is adjustable relative to the piston (8) and that the tamper-evident device (317) has a decoupling device with an actuator (328) which is in the range of motion (325) protrudes.

29. Injection device according to one or more of claims 1 to 28, characterized in that the actuating member (328) forms a stop for the actuator (324) for permanent uncoupling of the coupling elements (319, 321).

30. Injection device according to one or more of claims 1 to 29, characterized in that the coupling device (7) and the tamper-evident device (317) in the region, preferably inside, of an approximately cylindrical recess (316) of the piston (8 ) are arranged.

31. Injection device according to one or more of claims 1 to 30, characterized in that the coupling device (7) and the tamper-evident device (27) projecting in the region of an end face of the piston rod (5) in the direction of the piston (8) , are arranged approximately finger-like coupling elements (319).

32. Injection device according to one or more of claims 1 to 31, characterized in that the coupling elements (319, 321) connected to the piston rod (6) and / or the piston (8) have an end face of the piston rod (6) and / or protrude from the piston (8) in the direction of the longitudinal axis (318) and are designed to be elastically deformable in a plane perpendicular to the longitudinal axis (318).

33. Injection device according to one or more of claims 1 to 32, characterized in that the with

Piston (8) and the piston rod (6) connecting coupling elements (319, 321) are formed by annularly arranged, resiliently deformable locking fingers in radial direction.

34. Injection device according to one or more of claims 1 to 33, characterized in that the coupling elements ⁽ 319, 321 ⁾ , in particular the latching fingers, are arranged within a conical, preferably conical, envelope surface.

35. Injection device according to one or more of claims 1 to 34, characterized in that the coupling elements (319) connected to the piston rod (6) are provided with projections (320) which are formed by a stop with which Piston connected coupling element (321) is assigned.

36. Injection device according to one or more of claims 1 to 35, characterized in that a distance between the coupling elements (319), in particular the detent fingers, in the end region facing the actuating member (328) is smaller than a distance between the shoulders (320) of the coupling elements (319,) or an enveloping circle diameter surrounding them, the coupling elements (321) which are connected in motion with the pistons (8).

37. Injection device according to one or more of claims 1 to 36, characterized in that the coupling elements (319, 321) connected to the piston (8) and / or the piston rod (6) by the actuator (324) in radia¬ ler direction adjusted, in particular deformed and overlap in the direction parallel to the longitudinal axis (318) or engage in one another.

38. Injection device according to one or more of claims 1 to 37, characterized in that a distance running in the diametrical direction or the diameter of one surrounds the projections (320) of the coupling elements (319). the enveloping circle in the decoupling position is smaller than an opening width between those formed by the support surfaces (322) of the piston (8)! Coupling elements (321).

39. Injection device according to one or more of claims 1 to 38, characterized in that the approximately cylindrical actuator (324) has an outer diameter (342) which is greater than a distance in the radial direction or a inner envelope between the coupling elements (319) in the uncoupling or rest position.

40. Injection device according to one or more of claims 1 to 39, characterized in that the longitudinal play between the coupling elements (319, 321) extending in the direction of the longitudinal axis (318) is equal to or greater than a length of an approximately cylindrical expansion surface the actuator (324) or the actuators.

41. Injection device according to one or more of claims 1 to 40, characterized in that a distance (327) between the projections (320) or an enveloping circle diameter surrounding them is greater than the opening width between when the coupling elements (319) are in the use position the coupling elements (321) formed by the stops or support surfaces (322) of the piston (8) and / or the piston rod (6).

42. Injection device according to one or more of claims 1 to 41, characterized in that the actuating member (328) of the unlocking or triggering device is motionally connected to the piston (8) and / or the piston rod (6) and extends in the direction of the coupling elements (319, 321).

43. An injection device according to one or more of the An¬ claims 1 to 42, characterized in that the Betäti¬ supply member ^{⁽³²⁸⁾} in the direction of the longitudinal axis (318) has a length, the area equal to or greater than a length of a ground (323) between the coupling elements (319) and the actuator (324).

44. Injection device according to one or more of claims 1 to 43, characterized in that the coupling elements (319) and the actuating member (328) are in the

Cover the uncoupling position of the coupling elements (319, 321) in the axis-parallel direction by a length which is equal to or greater than a distance in the radial direction or an inner envelope circle between the coupling elements (319) which are in the rest position.

45. Injection device according to one or more of claims 1 to 44, characterized in that in the end region of the coupling elements (319) there is a free space (331) for the actuator between the inner side surfaces opposite the facing projections (320) (324) is arranged ^* and a distance (337 ⁾ between the inner side surfaces of the coupling elements (319) is greater than a diameter (338) or a distance between at least two spreading surfaces (344) of the Actuator (324).

46. Injection device according to one or more of claims 1 to 45, characterized in that the actuator (324) is formed in one piece from two cylindrical bodies having a different diameter.

47. Injection device according to one or more of claims 1 to 46, characterized in that an extension (345) projecting in the direction of the longitudinal axis (318) is arranged on the side surface of the coupling element (319).

48. Injection device according to one or more of claims 1 to 47, characterized in that a height of the extension (345) corresponds approximately to half the difference between the different diameters of the actuator (324).

49. Injection device according to one or more of claims 1 to 48, characterized in that at least one of the actuating member (328) opposite end face of the actuator (324) extends in the direction of the longitudinal axis (318) and is elastic therein deformable spacer element (348) is arranged.

50. Injection device according to one or more of claims 1 to 49, characterized in that the spacer element (348) is designed to be kink-elastic over at least one weakening cross-section (359).

51. Injection device according to one or more of claims 1 to 50, characterized in that the spacer element (348) has a snap-in over-center lock in the event of a relative movement exceeding a preset stroke.

52. Injection device according to one or more of claims 1 to 51, characterized in that the decoupling device is formed by a locking device (364) which is effective in the radial direction and is arranged between the coupling elements (319) of the piston rod (6). 53. Injection device according to one or more of claims 1 to 52, characterized in that the coupling elements (319) are provided on the mutually facing sides with locking projections projecting in the same direction.

54. Injection device according to one or more of claims 1 to 53, characterized in that an overlap width of the latching lugs is greater than a double overlap width of the coupling elements (319).

55. Injection device according to one or more of claims 1 to 54, characterized in that the actuator (324) or the tensioning member (428) is provided with an external thread (430), in particular a steep thread, which in the area of the lugs ( 320) is assigned an internal thread (425) of the same type.

55. Injection device according to one or more of claims 1 to 55, characterized in that a lifting height (433) of the tensioning member (428) is of different sizes.

57. Injection device according to one or more of claims 1 to 56, characterized in that the latching arms (423) with one against the piston (B ⁾ and one against the

Tendon (428) projecting approach (320) are provided.

58. Injection device according to one or more of claims 1 to 57, characterized in that the piston rod (6) is provided with guide flanges (421) which are designed as support arms (437) in the end region facing the piston, and Can be adjusted in the radial direction with respect to the central web (439) of the piston (6) via slots (43B). 59. Injection device according to one or more of claims 1 to 5B, characterized in that a projection (440) is arranged at a distance corresponding to a feed size (436 ⁾ from the end of the syringe barrel (2) facing the piston rod and a height of the projection is greater than a coverage width between the end face of the piston (8) and the end faces of the support arms (437) facing it.

60. Injection device according to one or more of claims 1 to 59, characterized in that a length of a guide surface of the support arms (437) is equal to or greater than a length of the lugs (320) on the side facing the actuator (324) plus one possible distance in the direction of the longitudinal axis (318) between the actuator (328) and the actuator (324).

51. Injection device according to one or more of claims 1 to 5, characterized in that a distance between an end face of the actuating member (328) facing the actuator (324) and the end position of the coupling elements (319) closest to the piston surface is greater as a length of the approaches (320). on the side facing the actuator (324).

62. Injection device according to one or more of claims 1 to 61, characterized in that the support arms (437) on the side facing the syringe barrel (2) have a link (443) arranged between them and the piston (8) is arranged between the piston rod (6) and the inner side of the syringe barrel (2) facing it, securing ring (442).

63. Injection device according to one or more of claims 1 to 62, characterized in that the piston (402) carries a locking part (406) projecting from the syringe cone (405), the largest outer diameter (a) of which is larger than the smallest Inner diameter (b) of the syringe cone ⁽ 405), and that the locking part (406) can be locked in the syringe cone ⁽ 405) at the end of the syringe stroke.

64. Injection device according to one or more of claims 1 to 63, characterized in that the locking part (406) has axial slots (414).

65. Injection device according to one or more of claims 1 to 64, characterized in that the locking part (406) is designed as a pin which can be inserted into the piston end face.

66. Injection device according to claim 63, 64 or 65, characterized by the fact that the piston end face carries elastically deformable stops projecting in the axial direction. ι

57. Injection device with a cylinder (401), a piston (402) sealingly guided therein and a syringe cone (405) onto which a cannula can be plugged, characterized in that the syringe cone (405) has a predetermined breaking point, in particular a circumferential groove (409), is equipped and carries on its circumference drivers (410) above the predetermined breaking point, which can be operatively connected to drivers on the inner circumference of a receiving opening for the cannula in the piston. 68. Injection device according to claim 67, characterized in that the drivers on the syringe cone (405) are designed as external teeth and the drivers on the inner circumference of the receiving opening of the piston (402) are designed as internal teeth.

B e z u g s z e i c h e n a u f s t e l l u n g

1 injection device 41 drive ring

2 syringe cylinders 42 middle part

3 Coupling arrangement 43 piston rod body

4 injection needle 44 attachment surface

5 outlet 45 spring

6 piston rod 46 slot

7 coupling device 47 width

8 pistons 48 end face

9 release device 49 circlip

10 inner wall 50 inner surface

11 cylinder chamber 51 claw

12 Opening 52 hole

13 cylinder chamber 53 bore

14 approach 54 coupling pin

15 coupling element 100 distance

16 projection 101 contact surface

17 coupling element 102 control edge

18 circlip 103 inner diameter

19 support arm 104 diameter

20 Distance 105 control bar / control surface

21 coverage width 106 diameter

22 handle 107 length 23 drug 108 length

24 Free space 109 Cover length

25 central axis 110 lifting height

26 Length 26 'traction 111 air

27 Tamper-evident device 112 arrow

28 spring element 113 needle channel

29 slot 114 outlet opening

30 approach 115 needle opening

31 leg end 116 coupling element

32 extension 1f7 connecting element

33 inner surface 118 diameter

34 circlip 119 arrow 35 circumferential surface 120 stroke

35 inner diameter 121 knobs

37 outside diameter 122 approach

38 driver 123 line 39 arrow 201 tamper evident

40 weakening area 202 longitudinal axis 215 Opening device 338 diameter 221 solution 339 outer width 231 rear 340 width

239 guide extension 341 opening

240 recess 342 diameter

241 projection 343 transition

242 locking arm 344 spreading surface

243 locking nose 345 extension

244 support surface - 346 arrow

245 cone angle

347 locking pin

246 support surface part 348 spacer element

247 expanding ring 349 spring arrangement

248 arrow 350 spring element

249 bead 351 slot

250 recess 352 joint arrangement

251 distance 353 push rod

252 expanding core 354 extension

253 distance 355 pivot bearing

254 spreading path 356 arrow

255 coverage width 357 connecting line

255 locking lug 358 expansion element

314 piston surface 359 weakening cross-section

315 guide extension 360 diameter

316 recess 361 diameter

317 Tamper-evident device 362 Opening

318 longitudinal axis 363 inner surface

319 coupling element 364 locking device

320 approach 365 extension

321 coupling element 366 stroke

322 support surface 367 width

323 support surface 36B

324 actuator 369 end face

325 Movement area 370 Recess 326 End wall 371 Free space

327 distance 372 opening width

32B actuator 401 cylinder 329 arrow 402 piston 330 face 403 face

331 clearance 404 guide rib

332 depth 405 syringe cone

333 length 406 locking part 334 height 407 heel

335 width 408 stop

336 distance 409 circumferential groove

337 distance 410 drivers 411 cannula

412 grip area

413 internal toothing 414 slot

415 gearing

416 stop 420 central part 421 guide flange

422 end face

423 locking arm

424 locking lug 425 internal thread

426 head start

427 recess

428 tendon 429 front

430 external thread

431 arrow

432 middle longitudinal matter

433 lifting height

434 recess

435 Tamper-evident device

436 feed size

437 support arm 438 slot

439 Mittelsteg

440 head start

441 end face 442 circlip

443 backdrop

444 inside diameter

445 diameter 446 contact surface

447 length

448 length

449 guide surface 450 swivel angle