Title - VETERINARY SYRINGE

Abstract

A veterinary syringe is provided having a main body (2), comprising a syringe cylinder (3) having a dispensing front end (4) and a rear end (11) for receiving the fluid to be dispensed, a plunger stem (8) having a front end portion (9) with a plunger (K) movably disposed along a displacement direction (10) in the syringe cylinder (3), and a rear end portion (12) located outside the syringe cylinder (3), a handle (13) having a front gripping portion (14) on the main body (2) and a rear gripping portion (15) pivotally attached to the front gripping portion (14), and a dosing device (50) for adjusting the volume of fluid to be dispensed, wherein the rear end portion (12) of the plunger stem (8) is pivotally attached to the rear gripping portion (15) such that,By rotating the rear gripping portion (15) in the direction of the main body (2), the plunger rod (8), and therefore the plunger (K), moves in the syringe cylinder (3) towards the front dispensing end (4) in order to dispense the fluid present in the syringe cylinder (3), wherein the dosing device (50) is disposed in the main body (2) and provides an adjustable front stop (58) for the plunger rod (8), wherein said stop defines a minimum distance between the plunger (K) and the front dispensing end (4), which can be reached when the plunger (K) moves in the syringe cylinder (3) towards the front dispensing end (4), wherein the adjustable front stop of the dosing device (50) can be brought to at least two predetermined adjustment positions, wherein the position of the front stop (58) differs in the direction of travel (10), and therefore,By adjusting one of the adjustment positions, the maximum stroke of the plunger rod (8), and therefore the maximum volume of fluid that can be dispensed, can be fixed, wherein the rear end portion (12) of the plunger rod (8) is pivotally fixed to the rear clamping part (15) such that a relative pivot movement between the plunger rod (8) and the rear clamping part (15) is the only possible relative movement between the plunger rod (8) and the rear clamping part (15).

Description

The present invention relates to a veterinary syringe having a dosing device for administering, for example, medications in different preselectable quantities. Common known difficulties with known veterinary syringes include that they are difficult to handle to adjust the different preselectable quantities, that medication is undesirably lost when redosing a syringe, and that ergonomic handling is poor because, for example, a plunger rod protrudes backward beyond the handle. The object of the present invention is therefore to make available an improved veterinary syringe. The invention is defined in claim 1. Advantageous developments are specified in the dependent claims. The veterinary syringe may have a main body, comprising a syringe barrel, having a forward dispensing end, for receiving fluid to be dispensed, a plunger rod, having a forward end portion with a plunger, which is movably arranged along a travel direction in the syringe barrel, and a rear end portion, which is located outside the syringe barrel, a handle, which has a front grip portion on the main body and a rear grip portion, which is 2095244 of 42 pivotally attached to the front grip portion, and a metering device for adjusting the volume of fluid to be dispensed. The rearward end portion of the plunger rod may be pivotally attached to the rear grip portion (preferably to a portion of the rear grip portion facing the front grip portion) such that, by pivoting the rear grip portion in the direction of the main body, the plunger rod, and hence the plunger, moves in the syringe barrel toward the front dispensing end to dispense fluid present in the syringe barrel.The metering device may be arranged in the main body and may provide an adjustable front stop for the plunger rod, said stop defining a minimum distance between the plunger (e.g., the plunger surface of the plunger) and the forward dispensing end that can be reached when the forward end portion of the plunger rod moves in the syringe barrel toward the forward dispensing end. This defines how far the plunger is maximally movable in the direction of the forward dispensing end. The adjustable front stop of the metering device may be positioned in at least two predetermined adjustment positions, in which the position of the front stop in the travel direction differs, and thus, by adjusting one of the adjustment positions, the maximum stroke of the plunger rod and thus the maximum volume of fluid that can be dispensed can be adjusted. Since the rear end portion of the plunger rod is pivotally attached to the gripping rear portion, the plunger rod does not protrude above the gripping rear portion and therefore the portion 2 2095244 of 42 rear grip can be ergonomically configured. Therefore, no part of the piston rod (e.g., the rear end portion of the piston rod) protrudes beyond the side of the rear grip portion facing away from the main body. In particular, the side of the rear grip portion facing away from the main body can be configured as a continuous surface. Since the rear end portion of the piston rod is pivotably attachable to the rear grip portion (preferably to a portion of the rear grip portion facing the front grip portion), the side of the rear grip portion facing away from the main body can be configured as a continuous surface, in particular even in the portion opposite the pivotable attachment of the rear end portion.In addition, the side of the rear grip that faces away from the main body can be ergonomically shaped. Of course, the front grip can also be ergonomically configured. The rear grip part can preferably pivot about a first pivot axis relative to the front grip part. The first axis of rotation can extend perpendicular to the direction of travel. In particular, the rear end portion of the shaft is fixed to the rear grip part in a connection region, such that only relative rotation about a second pivot axis, which passes through the connection region, is possible. This connection region is preferably formed in a portion of the rear grip part that faces the front grip part. The second axis of rotation can extend perpendicular to the direction of travel and / or parallel to the 2095244 of 42 first axis of rotation. Due to the adjustability of the front stop in the travel direction, only the set amount of fluid or volume is discharged. If the syringe barrel is refilled, the syringe barrel is completely filled again, and adjusting the front stop does not result in any loss of the fluid contained in the syringe barrel. The fluid can be, in particular, a liquid. The fluid can be a medication, a vaccine, or similar. The metering device may have a rotating element rotatably mounted on the main body and comprising a stop element (e.g., a rib) for each of the predetermined injection positions. The stop elements may be arranged spaced apart from one another in the direction of rotation of the rotating element, so that, by rotating the rotating element, the desired stop element can be positioned as a front stop. In this way, the maximum volume of fluid that can be dispensed can be adjusted reliably and easily (simply by rotating the rotating element). The stop elements may be arranged in a helical main path surrounding a channel through which the piston rod extends. This enables a compact configuration of the dosing device. The rotating element may have a part of 2095244 of 42 cylindrical locking grooves, each groove being assigned to one of the stop elements, and the main body having a locking element which, in the predetermined adjustment positions, is locked into one of the grooves. The desired stop position can therefore be reliably selected and adjusted. The grooves of the locking portion may be formed on an outer circumferential surface of the rotating member (e.g., a cylindrical portion). The piston rod may have a piston rod stop which, when the minimum distance is reached, comes into contact with the front stop. The piston rod stop may be band-shaped and extend in the longitudinal direction of the piston rod and radially. The piston rod stop can have a concavely curved stop surface, for example. In this case, it is preferred that the stop surfaces provided by the stop elements be convexly curved, so as to ensure reliable contact between the two stop surfaces of the piston rod stop, on the one hand, and the correspondingly selected stop element, on the other hand. Of course, it is also possible for the stop surfaces of the stop elements to be concave and for the stop surface of the piston rod stop to be convex. Furthermore, the stop surfaces can be flat. In particular, the rear end portion of the plunger rod is pivotally fixed to the 5-part 2095244 of 42 rear clamping such that a relative pivoting movement between the piston rod and the rear clamping part is the only possible relative movement between the piston rod and the rear clamping part. Therefore, for example, a relative movement in and transversely with respect to the longitudinal direction of the piston rod between the piston rod and the rear gripping part is not possible. Such pivotable fastening of the rear end portion of the piston rod to the rear gripping part may also be referred to as a fixed mounting of the piston rod. The plunger rod can be guided in the main body (in particular the plunger in the syringe barrel) in such a way that the plunger rod (or the plunger) is displaceable or movable only along the direction of travel. By means of the fixed mounting of the plunger rod, a movement component transversely to the direction of travel (or transversely to the longitudinal direction of the plunger rod) can therefore occur at the rear end portion of the plunger rod when the rear gripping part is pivoted towards the front gripping part. This results from the fact that, when the rear gripping part is rotated, the connection region of the pivotable attachment to the rear gripping part moves in a circular arc, with the center point of the circular arc located on the axis of rotation of the two gripping parts.The piston rod can therefore be provided with such elasticity (or, for example, flexibility) that this component of movement transverse to the direction of travel is compensated. This compensation can therefore be achieved, in particular, by means of the. 2095244 of 42 transverse motion component with respect to the direction of travel leading to bending or deflection of the piston rod, which is possible due to the elasticity provided for the piston rod. The handle can be configured such that a spring element is provided separating the two gripping parts. Thus, a basic position of the veterinary syringe can be provided, and to use the syringe, a user must move the rear gripping part in the direction of the front gripping part against the force of the spring. In particular, the syringe (particularly the main body or a portion thereof) may have a rear stop that limits movement of the plunger rod from the forward dispensing end in the opposite direction to the travel direction. The position of the rear stop is preferably fixed and cannot be changed, and the position of the rear stop therefore defines the basic position of the syringe (or the maximum possible pivoting of the rear gripping portion relative to the front gripping portion). The syringe according to the invention may have a connection for a fluid reservoir (or a connector for a fluid reservoir), wherein the connection is fluidly connected to the syringe barrel via a fluid connection. A non-return valve may be provided in the fluid connection to the syringe barrel, said non-return valve blocking the fluid connection and opening only when the pressure in the fluid connection upstream of the non-return valve is higher than the pressure in the 2095244 of 42 syringe barrel at a predetermined value. The connection (or connector) for connecting a fluid reservoir may be formed on the rear of the grip. Fluid may be connected to the syringe barrel from the connection (or connector) via a feed channel extending through the plunger rod. In particular, for this purpose, a non-return valve may be provided on the plunger rod (preferably on the front part thereof), said non-return valve opening only when the pressure in the feed channel is higher than the pressure in the syringe barrel by a predetermined value. Furthermore, the forward dispensing end may be fluidically connected to a forward end of the syringe through a dispensing channel and a non-return valve may be provided in the dispensing channel, said non-return valve opening only when the pressure in the barrel exceeds a predetermined value (relative to the external pressure). The veterinary syringe is therefore preferably designed as a self-filling syringe, since after the predetermined volume of fluid has been dispensed through the non-return valve into the dispensing channel, the rear gripping part is moved away from the dispensing end again by the pretensioning of the spring. This also leads to a corresponding movement of the plunger, as a result of which a negative pressure is generated in the syringe barrel, which leads to the opening of the non-return valve by 8. 2095244 of 42 the plunger rod such that, due to the now free fluid connection from the syringe barrel to the fluid reservoir, the fluid can be drawn from the fluid reservoir into the syringe barrel. As soon as the plunger rod has moved to the rear stop of the syringe, the non-return valve on the plunger rod closes again and the syringe barrel is completely filled again. However, any other design is also possible to provide a self-filling syringe. Thus, a connection for a fluid reservoir can also be provided in the main body or in the syringe barrel itself, with this connection being sealed by a non-return valve that opens only when there is negative pressure in the syringe barrel. In this case, a feed channel in the plunger rod is not required. In the veterinary syringe, the plunger can be securely connected to the front part, with the non-return valve accessible for maintenance purposes (e.g., cleaning) after the plunger is separated from the end part. In addition, an actuatable safety mechanism can be incorporated to prevent the plunger from being unintentionally detached, as the plunger can only be detached from the front part after the safety mechanism is actuated. The detachable connection can be, for example, a screw connection, a bayonet connection or another connection. The safety mechanism may be configured as a rotation lock that blocks rotation (e.g., 2095244 of 42 the unscrewing) of the plunger with respect to the plunger rod (preferably around the longitudinal axis of the plunger rod). The safety mechanism may have a safety cavity as the first safety element and a safety tab as the second safety element. For safety purposes, the safety tab is received in the safety cavity (the safety tab is in contact with the safety cavity) and thus prevents the plunger from separating from the front portion. One of the two safety elements may be formed on the plunger and the other on the front portion. The safety cavity can be configured, for example, as a passage opening in a corresponding wall or as a type of knockout (which does not extend through the entire thickness of the wall). The plunger may have a plunger portion with a plunger surface and a hollow cylindrical locking portion, wherein the first securing element is formed on the wall of the hollow cylindrical locking portion. The first locking element may be formed, for example, at the end of the locking portion facing away from the plunger portion. Furthermore, the hollow cylindrical locking portion may have an internal thread, and the front end portion may have an external thread interacting with the internal thread. The internal thread may have at least one non-threaded region extending (preferably straight) in the longitudinal direction of the hollow cylindrical fixing portion. Therefore, the internal thread may also 2095244 of 42 is referred to as an interrupted internal thread. The at least one thread-free region preferably extends into the end region of the internal thread at the end of the internal thread facing away from the plunger portion. The thread-free region may also extend along the entire internal thread. The internal thread may have two of the thread-free regions which then preferably lie opposite each other. The at least one non-threaded region of the internal thread is preferably offset in the circumferential direction relative to the first fastening element. The hollow cylindrical fixing portion is preferably configured so as to be elastic and deformable. The external thread may have at least one non-threaded region extending (preferably straight) in the longitudinal direction of the piston rod. Therefore, the external thread may also be referred to as an interrupted external thread. The at least one non-threaded region preferably extends into the end region of the external thread at the end of the external thread facing the piston portion. The non-threaded region may also extend over the entire length of the external thread. The external thread may have two thread-free regions which then preferably face each other. In particular, the at least one non-threaded region of the external thread may be offset in the direction 2095244 of 42 circumferential with respect to the second fixing element. It will be appreciated that the features mentioned above and the features to be explained below may be used not only in the combinations specified, but also in other combinations or alone, without departing from the scope of the present invention. The invention is explained in even more detail below on the basis of exemplary embodiments, with reference to the accompanying drawings, which likewise reveal features essential to the invention. These exemplary embodiments are illustrative only and should not be construed as restrictive. For example, the description of an exemplary embodiment with a multiplicity of elements or components should not be construed to mean that all of these elements or components are necessary for the implementation. Conversely, other exemplary embodiments may also contain alternative elements and components, fewer elements or components, or additional elements or components. Elements or components of different exemplary embodiments may be combined with one another, unless otherwise indicated.The modifications and variations described for one example embodiment may also apply to other example embodiments. To avoid repetition, the same or corresponding elements in different figures are designated with the same reference symbols and are not explained multiple times. In the figures: Fig. 1 shows a sectional view of a form of 2095244 of 42 embodiment of the veterinary syringe 1 according to the invention; Fig. 2 shows an isometric view of the piston rod 8 together with the piston K; Fig. 3 shows a front view of the piston rod 8 and the piston K; Fig. 4 shows a sectional view of the piston rod together with the plunger K along the section line AA of Fig. 3; Fig. 5 shows an enlarged view of detail C of Fig. 4; Fig. 6 shows a sectional view of the piston rod together with the plunger K along the section line BB of Fig. 4; Fig. 7 shows an isometric view of the piston rod 8; Fig. 8 shows a front view of the piston rod 8 of Fig. 7; Fig. 9 shows a sectional view of the piston rod along section line AA of Fig. 8; Fig. 10 shows an isometric view of the plunger K; Fig. 11 shows a front view of the plunger K; Fig. 12 shows a sectional view of the plunger K along the axis of the piston. 2095244 of 42 along the section line AA of Fig. 11; Fig. 13 shows a top view of the connecting piece 23; Fig. 14 shows an isometric view of the connecting piece 23; Fig. 15 shows a front view of the connecting piece 23; Fig. 16 shows a sectional view of the connecting piece 23 along the section line AA of Fig. 15; Fig. 17 shows a front view of the rear clamping piece 15; Fig. 18 shows a sectional view of the rear gripping part 15 along the section line AA of Fig. 17; Fig. 19 shows an isometric view of the rear grip part 15; Fig. 20 shows an isometric view of the rotating element 51; Fig. 21 shows a top view of the rotating element 51, and Fig. 22 shows a sectional view of the rotating element of Figs. 20 and 21. 2095244 of 42 In the embodiment shown in Fig. 1 , the veterinary syringe 1 according to the invention comprises a main body 2 with a syringe barrel 3 for receiving the fluid to be dispensed (e.g. a medicament or vaccine in liquid form). The syringe barrel 3 is removably connected to a main part 21 of the main body 2 by means of a threaded connection and comprises a front dispensing end 4 opening into a dispensing channel 5 in which a first non-return valve 6 is seated. It is possible, for example, to couple a cannula, not shown, to the front end 7 of the dispensing channel 5. The syringe 1 further comprises a plunger rod 8 which, with its front end portion 9, is arranged movably along a travel direction 10 in the syringe barrel 3. A plunger K is arranged at the front end portion 9, which plunger, when moved in the direction of the front dispensing end 4, causes fluid to be dispensed out of the syringe barrel 3 through the front dispensing end 4 and the dispensing channel 5, since the first non-return valve 6 is opened due to the pressure built up in the syringe barrel 3 by the movement of the plunger. The plunger rod 8 extends out of the main body 2 beyond a rear end 11 of the syringe barrel 3 and, as will be described in detail later, is connected by its rear end portion 12 in an articulated manner to a rear grip portion 15 of a handle 13 of the syringe 1. The handle 13 has a front grip portion 14 formed 2095244 of 42 on the main body 2 (here in the main portion 21) and the rear grip portion 15. The front grip portion 14 has an upper portion 16 projecting upwardly from the main body 2 and a lower portion 17 projecting downwardly from the main body 2. At the free end 18 of the lower portion 17 of the front grip portion 14, the rear grip portion 15 is pivotally mounted about a first pivot axis (here running perpendicular to the drawing plane of Fig. 1), wherein a spring F provided between the two grip portions 14 and 15 urges the two grip portions 14 and 15 apart. As can be easily seen from the sectional illustration of Fig. 1, the handle 13 is substantially V-shaped. In the basic position of the syringe 1 shown in Fig. 1, the front end portion 9 of the plunger rod 8 lies against a rear stop 19 formed in the main portion 21 and therefore cannot move further away from the front dispensing end 4 in the opposite direction to the travel direction 10. Due to the spring F, this basic position is maintained if no external force is exerted on the rear holding part 15. As can be seen in particular from Figures 1, 4, 5, and 9, the plunger rod 8 comprises a main plunger rod portion 81 with a feed channel 20 which extends through the main plunger rod portion 81 in the longitudinal direction of the plunger rod 8 and which is fluidly connected to the interior of the syringe barrel 3 via a connection channel 21 in the front end portion 9 and a passage opening 70 in the plunger K, a second non-return valve 22 being arranged in the feed channel 20. 2095244 of 42 connection channel 21. In order to be able to mount the second check valve 22 on the front end portion 9 and to be able to, for example, clean it for maintenance purposes, the piston K is removably fixed to the front end portion 9 by means of a screw connection. In detail, the piston K, as can be seen in particular in Fig. 5, comprises a piston portion 71 with a piston surface 72 and an annular piston groove 73 in which a piston sealing ring 74 is received. The piston portion 71 is adjacent to the front end portion 9 by means of a screw. The piston portion 71 is connected to a hollow cylindrical fixing portion 75 which has an internal thread 76 which is not configured continuously in the circumferential direction, but has two opposite threadless regions 77 (Figs. 10 and 12). On the wall of the hollow cylindrical fixing portion 75, a safety recess 79 (or first safety element) is formed at the end 78 which is directed away from the plunger portion 71. Furthermore, on the wall of the hollow cylindrical fixing portion 75 there is a marking 80, which indicates how the second check valve 22 is to be inserted into the connection channel 21. Since the passage opening 70 extends through the entire plunger portion 71 into the hollow cylindrical fixing portion 75, the desired fluid connection can be provided to the supply channel 20 into the syringe barrel 3 when the plunger K is screwed into the front end portion 9. 2095244 of 42 For the screwing-in operation, an external thread 81 is formed on the outside of the front end portion 9, the external thread being interrupted in the circumferential direction by two non-threaded regions 82 which preferably lie opposite one another (Fig. 7-9). At the front end of the front end portion 9, an annular groove 83 is formed in which a sealing ring 84 is received (Fig. 5). Furthermore, the front part 9 is provided with a radially protruding safety tab 85 (or second safety element) which is spaced from the external thread 81 (Fig. 7 and 8) in the direction of the rear end part 12 of the piston rod 8. The dimensioning of the non-threaded regions 82 in the circumferential direction of the external thread 81 is selected in combination with the dimensioning of the non-threaded regions 77 of the internal thread 76 of the shank K such that the shank K can be screwed into the front end portion and a permanent threaded connection is possible. Before the end 78 of the hollow cylindrical fastening portion 75 strikes against the safety tab 85 during the screwing-in process, it is sufficient for the hollow cylindrical fastening portion 75 to be pressed into the areas of the non-threaded regions 77.Due to the resulting deformation of the fixing portion 75, the end 78 of the hollow cylindrical fixing portion 75 can move over the fixing tongue 85 during the screwing operation, and the fixing cavity 79 can be positioned such that, after the described pressing is completed, the hollow cylindrical fixing portion 75 relaxes to its main shape due to its elasticity (the deformation of. 2095244 of 42 the hollow cylindrical fixing portion 75 is thus made reversible). Since the plunger K is positioned such that the fixing cavity 79 faces the fixing tab 85, the fixing tab 85 is inserted into the fixing cavity 79, as shown in Fig. 2 to 6. In this way, the fixing tab 85 engages in the fixing cavity 79, whereby a protection against rotation or a fixing against rotation is obtained. Even if a rotating force is exerted on the piston K, an unwanted unscrewing of the piston K from the front part 9 can be reliably prevented, since the safety tab 85 is inserted into the safety cavity 79 and thus the unscrewing of the piston K from the front part 9 is reliably prevented. For example, when unscrewing the cylinder 3 from the main part 21 of the main body 2 for cleaning purposes, an unwanted rotating force on the piston K may occur if, for example, due to dirt, the friction between the cylinder 3 and the piston K is greater than the friction between the piston K and the front part 9. If, after use of the syringe 1 according to the invention, the second non-return valve 22 has to be cleaned or maintained, the barrel 3 can first be unscrewed from the main portion 21 of the main body 2. Due to the rotational locking by means of the safety tab 85 and the safety recess 79, the plunger K remains here in the front portion 9. In order to now separate the plunger K from the front part 9, the hollow cylindrical fixing portion 75 must be deformed by being compressed in the region of the two opposite threadless regions 77, so that the cross-sectional shape of the portion 19 2095244 of 42 hollow cylindrical fastening 75 is no longer circular, but oval in the region of the fastening recess 79. As a result, the fastening recess 79 moves away from the front part 9 along the radial direction of extension of the guide tongue 85, so that the fastening tongue 85 no longer fits into the fastening recess 79. In this state, the unscrewing of the piston K can be started. The dimensioning of the safety tongue 85 and of the safety recess 79 in the longitudinal direction of the piston rod 8 is selected in the described embodiment such that, after a complete revolution (360°) of the piston K, the wall end 78 of the hollow cylindrical fastening portion 75 in particular no longer touches the safety tongue 85. The piston K can therefore be unscrewed further, since there is no longer a rotation lock. Once the piston K has been unscrewed, the second non-return valve 22 with its valve body 221, its valve spring 222 and its seal 223 is freely accessible and can be cleaned and maintained. The piston K can then be screwed back in as described above, so that the desired rotation lock is achieved by engaging the safety tab 85 in the safety recess 79. The rear end 12 of the rod 8 is connected to a connecting piece 23 (Fig. 1 and Fig. 13-16) which is rotatably mounted on the rear clamping piece 15 and has a tubular fixing 24. At the free upper end 25 (Fig. 1, 17 to 19) of the 2095244 of 42 rear gripping piece 15 is mounted a bottle adapter 26 with a piercing mandrel 27 (Fig. 1) which, for example, can pierce through a membrane of a medicine bottle (not shown) fixed to the bottle adapter 26 when the medicine bottle is fixed to the bottle adapter 26. The bottle adapter 26 further has a tube fitting 28 which is fluidly connected to the piercing mandrel 27. The two ends of a tube 29 are introduced into the two tube adapters 28 and 24, so that the piercing mandrel 27 (and thus the contents of the corresponding medicine bottle) is fluidly connected to the feed channel 20 of the piston rod 8 through the connecting piece 23. The bottle adapter 26 also has a ventilation channel 30 which runs through the drilling mandrel 27 and is connected to the environment via a third non-return valve 31 to prevent the formation of excessive negative pressure in the medicine bottle during the extraction of the liquid. Syringe 1 is configured as what is called a self-filling syringe which, after a discharge operation, automatically fills the barrel 3 of the syringe with the amount of liquid discharged. The user of the syringe 1 can hold the handle 13 with his hand such that the index finger rests on the upper part 16, the middle finger, ring finger and little finger on the lower part 17 of the front grip part 14, and the palm of the hand and the thumb on the rear grip part 15. If the user then presses with his hand, he moves the rear grip part 15 in the direction of 21. 2095244 of 42 main body 2 against the force of the spring F, whereby the plunger rod 8 moves with its front part 9, and therefore with the plunger K, along the travel direction 10 in the syringe barrel 3 towards the front dispensing end 4. In this way a positive pressure is generated in the syringe barrel 3, which causes the first non-return valve 6 to open and thus the fluid can be dispensed through the dispensing channel 5. If the user opens his hand again, the rear gripping part 15 moves away from the main body 2 due to the force of the spring F, whereby the plunger rod 8 together with the front part 9 and the plunger K move in the syringe barrel 3 in the opposite direction to the travel direction 10.The first non-return valve 6 closes and a negative pressure is generated inside the cylindrical syringe 3, which causes the second non-return valve 22 in the front part 9 to open and the liquid from the medicine bottle to be drawn into the cylindrical syringe 3. The rearward movement of the rear gripping part 15 ends when the front part 9 rests on the rear stop 19. The second non-return valve 22 closes again and the inside of the syringe barrel 3 is completely filled again with the fluid to be dispensed. As shown in Figs. 13 to 16, a channel 35 formed in the connecting piece 23 is substantially V-shaped, the connecting piece 23 having a main member 36 with a connection 37 for the rear end portion 12 of the piston rod 8 and for fixing the tube 24 extending obliquely therewith. Two laterally extending pivot pins 38, 39 are formed in the main member 36 and are arranged in a longitudinal direction. 2095244 of 42 are inserted into the corresponding receptacles 40 (Fig. 1719) of the rear grip part 15, and thus the connecting piece 23 is rotatably mounted. By means of this configuration of the syringe 1, the rear end portion 12 of the plunger rod 8 is rotatably mounted in the rear grip part 15 such that a longitudinal or transverse relative movement between the plunger rod 8 and the rear grip part 15 is not possible. It can also be said that the rear end portion 12 of the plunger rod 8 is fixed to the rear grip part 15 in a connection region such that only relative rotation about a second axis of rotation passing through the connection region is possible. As can be seen in particular from Figs. 17-19 in conjunction with Fig. 1, this connection region is formed in a portion 42 of the rear grip part 15 that faces the front grip part 14. The second pivot axis preferably extends perpendicular to the direction of travel and / or parallel to the first pivot axis around which the rear grip part 15 can pivot relative to the front grip part 14. This configuration of the fixing of the rear end portion 12 of the plunger rod 8 to the rear grip part 15 makes it possible for the rear side 41 of the rear grip part 15 facing away from the main body 2 to be ergonomically formed for better handling of the syringe 1. The rear part 41, and thus also in particular the portion of the rear part 41 which is opposite the connection region, can thus be configured continuously (without gaps or holes) and can have an ergonomic shape. 2095244 of 42 corresponding to a user's hand. Since the rear end portion 12 of the piston rod 8 is attached to the rear grip part 15 in the connection region in such a way that only relative rotation about the second axis of rotation is possible, the piston rod 8 is provided with a predetermined elasticity that allows the piston rod 8 to deflect. Thus, during pivoting of the rear grip part 15 towards the front grip part 14, a movement component transversely to the travel direction (or transversely to the longitudinal direction of the piston rod) may occur (e.g., from bottom to top in Fig. 1). This is due to the fact that, when the rear grip part 15 pivots, the connection region of the pivotable attachment with the rear grip part 15 moves in a circular arc, the center point of which lies on the pivot axis of the two grip parts 14, 15.Due to the predetermined elasticity of the piston rod 8, the transverse component of movement with respect to the travel direction leads to bending of the piston rod 8 in such a way that the transverse component of movement with respect to the travel direction is compensated. The elasticity is configured in such a way that the piston rod 8 deflects only to such an extent that the movement of the piston rod 8 with its front end portion 9, and thus with the piston K, in the syringe barrel 3 along the travel direction 10 towards the front dispensing end 4 is not impaired, and thus the piston K displaces easily in the syringe barrel 3. 2095244 of 42 The syringe 1 furthermore has a dosing device 50 which is arranged in the main body 2 and with which the maximum dispensable volume of fluid can be adjusted and fixed. For this purpose, the dosing device 50 comprises a rotating element 51 which is arranged at the rear end of the main body 2 and has a cap 61 (Fig. 1). The rotating element 51 comprises a cylindrical gripping portion 52, a cylindrical locking portion 53 adjacent to the latter, and a cylindrical inner portion 54 adjacent to said locking portion and provided with locking tabs 55, as can be easily seen in particular in Figs. 20 to 22, the end cap 61 not being shown in Figs. 20 to 22. Inside the rotating element 51, a cylindrical channel 56 is formed through which the piston rod 8 runs and is guided.Around the channel 56, stop elements 58 (e.g., ribs 58) are formed, which are spaced apart from one another in the circumferential direction on a helical main path 57 and which preferably have the same height here, so that their stop surfaces 59 facing away from the main path 57 are at different distances in the travel direction 10 from the front dispensing end 4. On the other side of the cylindrical locking portion 53, a groove 60 running in the longitudinal direction is provided for each stop element 58. In the inserted state, shown in Fig. 1, the rotating element 51 is rotatably mounted in the main body 2, with the piston rod 8 extending through the channel 56. 2095244 of 42 In the region of the cylindrical locking portion 53, the main portion 21 of the main body 2 has a projecting locking element 62 which, depending on the rotational position of the rotating element 51, is in locking with one of the longitudinal grooves 60. As can be seen, for example, in Figs. 1, 2, 4, 7 and 8, the plunger rod 8 has a plunger rod stop 65 which extends radially from the main portion of the plunger rod 81 and has a stop surface 66. By movement of the rear gripping portion 15, the plunger rod 8 can be moved in the direction of the forward dispensing end 4 until the stop surface 66 of the plunger rod stop 65 comes into contact with the stop surface 59 of the corresponding stop element 58 in the main helical path 57. Thus, the maximum stroke of the rod 8 for a discharge operation is defined, as a result of which the maximum discharge volume of the fluid inside the barrel 3 of the syringe is also defined. If the syringe 1 is in the basic position, shown in Fig. 1, the maximum desired discharge volume can be defined by rotating the rotating element 51 by actuating the gripping portion 52. Said discharge volume is defined in the main helical path 57 by the stop element 58 which is located opposite the stop 65 of the plunger rod. The maximum discharge volume can therefore be easily defined, ensuring that the user can always dispense the defined volume of fluid into the syringe barrel via the end. 2095244 of 42 front dispenser 4. In the embodiment described here, for example, the stop surfaces 59 of the directly adjacent stop elements can be spaced apart from each other by 1.3 mm in the displacement direction 10, whereby the discharge volume from 0.5 ml to 10 ml can be adjusted in 0.5 ml steps.

Claims

1. A veterinary syringe, having a main body (2), comprising a syringe cylinder (3), having a dispensing front end (4) and a rear end (11) for receiving the fluid to be dispensed, a plunger stem (8), having a front end portion (9) with a plunger (K), which is movably disposed along a displacement direction (10) in the syringe cylinder (3), and a rear end portion (12) located outside the syringe cylinder (3), a handle (13), having a front gripping portion (14) on the main body (2) and a rear gripping portion (15) pivotally attached to the front gripping portion (14), and a metering device (50) for adjusting the volume of fluid to be dispensed, wherein the rear end portion (12) of the plunger stem (8) is pivotally attached to the rear gripping portion (15) such that,By rotating the rear gripping portion (15) in the direction of the main body (2), the plunger rod (8), and therefore the plunger (K), moves in the syringe cylinder (3) towards the front dispensing end (4) in order to dispense the fluid present in the syringe cylinder (3), wherein the dosing device (50) is disposed in the main body (2) and provides an adjustable front stop (58) for the plunger rod (8), wherein said stop defines a minimum distance between the plunger (K) and the front dispensing end (4), which can be reached when the plunger (K) moves in the syringe cylinder (3) towards the front dispensing end (4), wherein the adjustable front stop of the dosing device (50) can be brought to at least two predetermined adjustment positions, wherein the position of the front stop (58) differs in the direction of travel (10), and therefore,By adjusting one of the adjustment positions, the maximum stroke of the plunger rod (8) can be fixed, and therefore the maximum volume of fluid that can be dispensed can be configured, characterized in that the rear end portion (12) of the plunger rod (8) is pivotally fixed to the rear clamping part (15) in such a way that a relative pivot movement between the plunger rod (8) and the rear clamping part (15) is the only possible relative movement between the plunger rod (8) and the rear clamping part (15), wherein the plunger rod (8) is guided in such a way that the plunger (K) is displaceable in the syringe cylinder (3) only along the displacement direction (10),and wherein the piston rod (8) is provided with such elasticity that a component of movement transverse to the direction of displacement (10) that occurs in the rear end portion (12) of the piston rod (8) when the rear gripping portion (15) pivots toward the front gripping portion (14) is compensated by flexing of the piston rod (8). Eleven claims follow.