Device for applying a fluid

Abstract

The invention relates to a fluid dispensing device comprising a cylinder (13), a piston (26) movable within the cylinder (13) between a front and a rear position and connected to a piston rod (25), and a clamping device (S) connected to the piston rod (25). The clamping device (S) has a ramp (42) that can be rotated by a motor (51) and comprises a ramp track (41) extending along a helical line. The clamping device (S) further has a roller (40) that contacts the ramp track (41) and is rotatably mounted on an impeller (31) connected to the piston rod (25), such that when the ramp (42) rotates in a first direction of rotation (52), the ramp track (41) passes under the roller (40), which is rotating at that time.A dosing adjustment device (36) is provided comprising a spacer (70) and a drive unit, wherein the drive unit can move the spacer (70) from a neutral position, in which the spacer (70) is not positioned between the impeller (31) and the cylinder (13), to an active position, in which the spacer is positioned between the impeller (31) and the cylinder (13), when the plunger (26) is in the rear end position such that the impeller (31) is stopped by the spacer (70) after the roller (40) passes over the transition region (46) and therefore the plunger stroke is shorter during a movement of the plunger (26) towards the open dispensing end compared to when the spacer (70) is in the neutral position. The spacer (70) has a through hole (140) through which a spindle (143) with a thread (142) is guided, and the spacer (70) has a pin (141) that engages with the thread (142).Said thread (142) opens into an annular groove (144, 145) at at least one of its ends.

Description

[0001] The present invention relates to a device for applying a fluid with the features of the preamble of claim 1, which may, for example, be designed as a needleless self-filling syringe with which a liquid drug, a liquid medicine, a liquid vaccine or the like can be administered intramuscularly to animals.

[0002] Such a device is known, for example, from DE 102018 107 102 A1. WO 03 / 103751 A1, WO 2018 / 107220 A1, WO 2017 / 117273 A1 and US 3 057 349 A describe devices that move a piston via a piston rod by means of a clamping device.

[0003] A device for applying a fluid of the type mentioned above should, on the one hand, be as light as possible and thus be portable by a user with one hand for a long time, and at the same time enable the desired needle-free intramuscular injection.

[0004] The object of the invention is therefore to provide such a device for applying a fluid.

[0005] The invention is defined in claim 1. Advantageous embodiments are specified in the dependent claims.

[0006] The device according to the invention for applying a fluid comprises a cylinder having an open dispensing end, a piston displaceable within the cylinder between a front and rear end position, the piston being connected to a piston rod extending along a first direction beyond a rear end of the cylinder opposite the open dispensing end, a check valve (acting as an outlet valve) closing the open dispensing end, and a clamping device connected to the piston rod. The clamping device can move the piston rod in a clamping operation along the first direction until the piston is in its rear end position, thereby filling the cylinder with the fluid to be applied and pre-tensioning the piston rod towards the open dispensing end. For this purpose, the device can have a connection opening into the cylinder. For example, a [missing information] can be attached to the connection.A hose or container holding the fluid to be applied can be attached and secured for use with the device. Preferably, the connection can include a check valve designed as an inlet valve that opens during the clamping process and closes when the fluid is applied. Similarly, the outlet valve closes during the clamping process and opens when the fluid is applied.

[0007] Furthermore, when the piston is in its rear end position, the clamping device can release the piston rod in a dispensing operation, so that the piston, due to the applied preload, moves against the first direction towards the open dispensing end, thereby dispensing fluid in the cylinder via the check valve for application.

[0008] The clamping device comprises a ramp rotatable by means of a motor, with a ramp track extending along a helical path. The ramp track rises from a first plateau along an incline to a second plateau and descends from the second plateau via a drop flank back to the first plateau. The ramp track includes a transition section connecting the second plateau and the drop flank. The clamping device may further comprise a roller contacting the ramp track, which is rotatably mounted in a driver connected to the piston rod. When the ramp is rotated along a first direction of rotation, the ramp track passes under the rotating roller. For the clamping process, the ramp track can be rotated along the first direction of rotation so that the roller runs on the incline section up to the second plateau, thereby moving the piston to its rear end position.For the dispensing process, the tensioning device can rotate the ramp track from a contact of the roller with the second plateau along the first direction of rotation until the roller runs over the transition area and accelerates towards the first plateau due to the pretension, thereby moving the piston towards the open dispensing end.

[0009] The device according to the invention is preferably designed as a self-filling syringe for needle-free application (especially intramuscularly) in animals and / or humans.

[0010] According to the invention, the motor can be connected to the ramp via a coupling, wherein the coupling transmits the torque provided by the motor in the first direction of rotation to rotate the ramp and provides a freewheel opposite to the first direction of rotation, which is designed to cover at least one rotation angle range corresponding to the transition range.

[0011] The clutch can be designed such that the freewheel covers a rotation angle range that is no more than twice the transition range. In particular, the freewheel can cover a rotation angle range that is 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% greater than the transition range.

[0012] The clutch can have a first clutch part connected to the motor and a second clutch part connected to the ramp. One of the two clutch parts can have a protruding engagement element, and the other clutch part can have a recess into which the engagement element fits. The extension of the engagement element in the first direction of rotation can be smaller than the extension of the recess in the first direction of rotation by at least the angle of rotation covering the transition area. Thus, the extension of the recess in the first direction of rotation is larger than the extension of the engagement element in the first direction of rotation, thereby providing the desired freewheel.

[0013] A spring can be arranged between a side face of the engagement element and a side face of the recess that face each other in the first direction of rotation. In particular, a spring can be arranged between all opposing side faces of the engagement element and the recess. The spring(s) can be attached to the engagement element.

[0014] The spring(s) can be designed as compression springs. In particular, they can be implemented as disc springs.

[0015] The engagement element can be designed as a bridge.

[0016] The first coupling part can include the engagement element. Furthermore, the ramp can comprise a base as the second coupling part, with the recess formed in the base.

[0017] One of the two coupling parts can have several projecting engagement elements spaced apart from each other in the first direction. The other of the two coupling parts can have several recesses into which the engagement elements fit. The extent of each engagement element in the first direction of rotation is smaller than the extent of the corresponding recess in the first direction of rotation by at least the angle of rotation covering the transition area.

[0018] According to the invention, the ramp track can run on the end face of a wall extending along a circular path, wherein a cover is provided that covers the ramp track, the driver and the roller and has at least one scraper extending in the opposite direction to the first direction, which extends within the wall to the inside of the wall and thus scrapes lubricant located on the inside from the inside.

[0019] The cover can have several wipers extending in the opposite direction to the first direction, each extending within the wall towards the inside of the wall and thus wiping lubricant located on the inside from the inside, the wipers being spaced apart from each other along the first direction.

[0020] The scrapers can differ in length from the first direction.

[0021] Furthermore, the wipers can differ in their extension towards the inside.

[0022] The scraper(s) can be formed on a frustoconical central section. In particular, they can extend radially from the frustoconical central section. The frustoconical central section can extend in the opposite direction to the first. In particular, the frustoconical central section can extend to the bottom of the ramp.

[0023] The middle section can also have any other shape. In particular, it can be cylindrical.

[0024] According to the invention, the piston rod can be connected to the driver via a joint.

[0025] In particular, to form the joint, the end of the piston rod facing away from the piston can be rounded and movably mounted in a bed.

[0026] The bed can be formed by a connecting part that presses against the rounded end of the piston rod by means of a screw screwed into the rounded end. The bed can also be formed by a curved side of a washer (or a compensating washer).

[0027] Furthermore, the joint can have two washers (or compensating washers) arranged one on top of the other, the facing sides of which are curved so that they move against each other when the piston rod rotates. The two washers can be arranged on a side of the connecting part facing away from the rounded end of the piston rod.

[0028] The joint can be designed as a pivot joint and / or as a joint with exactly one degree of freedom.

[0029] The joint can allow translational movement (preferably exactly one translational movement) perpendicular to the longitudinal direction of the piston rod.

[0030] According to the invention, the device for application can have exactly one cylinder with exactly one piston and exactly one piston rod, wherein the clamping device has two helical springs running parallel to each other, both of which contribute to the applied preload when the piston is in its rear end position.

[0031] The two coil springs can be spaced apart from each other transversely to their longitudinal direction and / or have the same dimensions.

[0032] In particular, the coil springs can be arranged so that their longitudinal directions are parallel to the longitudinal direction of the piston rod.

[0033] The coil springs can be designed as compression springs.

[0034] The piston rod can be connected to two guide rods via a connecting part, with each guide rod extending inside one of the coil springs.

[0035] The clamping device can have at least three helical springs running parallel to each other. In particular, the helical springs can be arranged symmetrically to the motor in a plane perpendicular to the longitudinal direction of the helical springs.

[0036] According to the invention, the device for applying a fluid can comprise a front part having the cylinder and the open dispensing end and a rear part having the clamping device, wherein the front part and the rear part are made of different materials.

[0037] The material of the front part can include titanium, steel or plastic, and the material of the rear part can include titanium, aluminum, magnesium or plastic.

[0038] The device can have a housing enclosing the front and rear parts, with a section of the front part protruding from the housing.

[0039] According to the invention, the device can comprise a metering adjustment device with a spacer and a motion unit, wherein the motion unit can move the spacer, when the piston is in its rear end position, from a neutral position in which the spacer is not positioned between the driver and the cylinder, to an active position between the driver and the cylinder, so that, after the roller has passed over the transition area, the driver is stopped by the spacer and thus the piston stroke is shorter when the piston moves to the open dispensing end compared to the case in which the spacer is in its neutral position.

[0040] The spacer may have a threaded bore into which a threaded rod is inserted, which is rotated to move the spacer between its neutral position and its active position.

[0041] The spacer can be guided in such a way that the spacer is only movable in a plane perpendicular to the piston rod.

[0042] The spacer can be designed in such a way that, when the driver is stopped by the spacer, the roller is not in contact with the spacer.

[0043] The spacer can have a first stop area and a second stop area for the driver, wherein the extension of the spacer along the first direction is smaller for the first stop area than for the second stop area, so that different piston stroke reductions can be set depending on whether the first or second stop area is moved into the active position of the spacer.

[0044] Of course, the spacer can also have three or more stop areas, whereby the extension of the spacer along the first direction is different for the stop areas, so that different piston stroke reductions can be set depending on which stop area is moved into the active position of the spacer.

[0045] According to the invention, the device can include a control unit that measures a characteristic parameter during a clamping and / or dispensing process and determines, by comparing this measurement with at least one predefined value, whether the clamping and / or dispensing process has been carried out as intended. In particular, the measurement of the characteristic parameter can be carried out during the dispensing process and the preceding clamping process, and, by comparing this measurement with the at least one predefined value, it can be determined whether both the clamping and dispensing processes have been carried out as intended.

[0046] Key parameters that can be measured include the current consumption of the motor, the acceleration acting on the application device and / or the sound (or noise; e.g. frequency spectrum, frequency(ies), pitch, energy and / or volume).

[0047] A target current profile with a lower limit and an upper limit can be specified as at least one target value, whereby the control unit determines the clamping process to be as intended if the measured current consumption during the entire clamping process is not less than the lower limit and not greater than the upper limit.

[0048] A target acceleration time profile with an upper limit can be specified as at least one target value, whereby the control unit determines the delivery process as being as intended if the measured acceleration during the entire delivery process is not greater than the upper limit.

[0049] A first upper and a first lower target frequency and / or a first upper and a first lower target amplitude can be specified as at least one target value, whereby the control unit determines the output process to be as intended if a principal frequency of the measured frequency spectrum lies between the first upper and the first lower target frequency and / or the amplitude of the principal frequency of the measured frequency spectrum lies between the first upper and the first lower target amplitude.

[0050] The term "major frequency" here refers specifically to the frequency of the measured frequency spectrum that exhibits the greatest amplitude. The major frequency is usually the frequency that determines the pitch.

[0051] The first upper target frequency can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, or 15% higher than a specified first main target frequency. Furthermore, the first lower target frequency can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, or 15% lower than the specified first main target frequency.

[0052] The first upper target amplitude can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, or 15% greater than a specified first main target amplitude. Furthermore, the first lower target amplitude can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, or 15% smaller than the specified first main target amplitude.

[0053] Furthermore, a second upper and a second lower target frequency and / or a second upper and a second lower target amplitude can be specified as at least one target value, whereby the control unit determines the output process as being as intended if a first secondary frequency of the measured frequency spectrum lies between the second upper and the second lower target frequency and / or the amplitude of the first secondary frequency of the measured frequency spectrum lies between the second upper and the second lower target amplitude.

[0054] The first secondary frequency is understood here to be, in particular, the frequency of the measured frequency spectrum that has the second highest amplitude and thus, after the main frequency, the largest amplitude.

[0055] The second upper target frequency can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, or 15% higher than a specified first target secondary frequency. Furthermore, the second lower target frequency can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, or 15% lower than the specified first target secondary frequency.

[0056] The second upper target amplitude can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, or 15% greater than a specified first secondary target amplitude. Furthermore, the second lower target amplitude can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, or 15% smaller than the specified first secondary target amplitude.

[0057] Of course, a second, third, fourth, fifth and / or further secondary frequencies (whose amplitudes are each smaller) can be measured and taken into account in the same way to evaluate the delivery process.

[0058] The output process is deemed to be functioning correctly if the principal frequency of the measured frequency spectrum is lower than the target frequency and / or the amplitude of the principal frequency of the measured frequency spectrum is greater than the target amplitude. The principal frequency, in this context, refers specifically to the frequency of the measured frequency spectrum that exhibits the greatest amplitude. The principal frequency is typically the frequency that determines the pitch.

[0059] The duration of the clamping process can be measured as a key parameter.

[0060] A first target duration can be specified as a predefined value, whereby the control unit determines the clamping process to be as intended if the measured duration is greater than the first target duration.

[0061] A second target duration can be specified as a predefined value, whereby the control unit determines the clamping process to be as intended if the measured duration is less than the second target duration.

[0062] Furthermore, the swept rotation angle of the ramp track along the first direction of rotation during the clamping process can be measured as a key parameter.

[0063] A target rotation angle can be specified as a predefined value, whereby the control unit determines the clamping process to be as intended if the measured swept rotation angle is greater than the target rotation angle.

[0064] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations given, but also in other combinations or on their own, without leaving the scope of the present invention.

[0065] The invention is explained in more detail below with reference to exemplary embodiments and the accompanying drawings, which also disclose essential features of the invention. These exemplary embodiments serve only for illustration and are not to be interpreted as limiting. For example, a description of an exemplary embodiment with a plurality of elements or components is not to be interpreted as meaning that all of these elements or components are necessary for implementation. Rather, other exemplary embodiments may also contain alternative elements and components, fewer elements or components, or additional elements or components. Elements or components from different exemplary embodiments may be combined with one another unless otherwise specified. Modifications and variations described for one of the exemplary embodiments may also be applicable to other exemplary embodiments.To avoid repetition, identical or corresponding elements in different figures are designated with the same reference symbols and are not explained multiple times. The figures show: . Fig. 1 a perspective view of an embodiment of the application device 1 according to the invention; Fig. 2 a front view of the cylinder-piston assembly 10 of the application device 1; Fig. 3 a sectional view of the cylinder-piston assembly 10 along section line AA in Fig. 2 ; Fig. 4 a sectional view of the cylinder-piston arrangement 10 along the section line BB in Fig. 3 ; Fig. 5 a sectional view of the cylinder-piston arrangement 10 according to section line CC in Fig. 4 Fig. 6 is an isometric view of the cylinder-piston assembly 10, wherein the device is tensioned and the piston is in its rear end position; Fig. 7 is an isometric view of the cylinder-piston assembly 10, wherein the piston is in its front end position; Fig. 8 is a diagram illustrating the path of the ramp track 41, wherein the angle of rotation α is plotted along the x-axis and the stroke along the longitudinal axis of the piston rod 25 is plotted along the y-axis; Fig. 9 is a sectional view of the piston-cylinder assembly 10 in the tensioned state according to Fig. 6 Fig. 10 a front view of the piston-cylinder assembly 10, with the piston in its forward end position; Fig. 11 a sectional view of the piston-cylinder assembly 10 along section line DD in Fig. 10 Figs. 12A-12C illustrate the forces when the roller 40 passes over the transition area 46 towards the ramp 47; Fig. 13 a front view of the base 60 of the ramp 42; Fig. 14 an isometric view of the coupling part 66 non-rotatably connected to the motor 51; Fig. 15 a side view of the coupling part 66; Fig. 16 a front view of the coupling part 66; Fig. 17 a front view of the coupling part 66 inserted into the recess 61 in the base 60; Figs. 18 and 19 illustrations according to Fig. 17 to explain the freewheel provided by the clutch 50; Fig. 20 a schematic front view of the spatial arrangement of the springs 32 and 33 and the motor 51; Fig. 21 a comparative view of the arrangement of a spring and the motor of a conventional application device; Figs. 22 and 23 further views of further embodiments for the spatial arrangement of spring and motor in the application device 1 according to the invention; Fig. 24 a view of the front part 11 and rear part 12 in the connected state; Fig. 25 a view of the front part 11 and the rear part 12 in the unconnected state; Fig. 26 an enlarged detail section of the metering adjustment device 36; Fig. 27A a perspective view of the spacer 70; Fig. 27B a schematic representation of a further embodiment of a spacer 70; Fig. 27C a view of a spacer 70 according to a further embodiment; Fig.27D the section view along the section line AA in . Fig. 27C ; Fig. 27E a representation according to Fig. 27C , where the spacer 70 is shown in its active position; Fig. 27 Fine perspective view of the spindle; Fig. 28 A perspective view of the cover 35; Fig. 29 A front view of the cover 35; Fig. 30 A sectional view along section line BB in Fig. 29 ; Fig. 31 a sectional view along the section line AA in Fig. 29 ; Fig. 32 a front view of the cover 31; Fig. 33 a sectional view of the cover 35 along the section line CC in Fig. 32 Fig. 34: An enlarged sectional view of the front part 11 including piston 26 and part of the piston rod 25; Fig. 35: A schematic sectional view of an insert 96 for the nozzle 16; Fig. 36: A schematic sectional view of piston rod 25, plate 28, guide rods 29 and 30, and springs 32 and 33; Fig. 37: An enlarged view of detail A of Fig. 36 ; Figs. 38 and 39: Diagrams with measured acceleration values ​​during the clamping and unclamping process; Figs. 40 and 41: Diagrams with measured current consumption of the motor 51 during a clamping and unclamping process.

[0066] At the in Fig. 1 In the illustrated embodiment, the device 1 according to the invention for applying a fluid (e.g., a liquid) comprises a housing 2 with a main section 3 and a handle section 4. The handle section 4 is designed so that a user can hold the device 1 by gripping the handle section. Furthermore, the handle section 4 has a trigger 5 for actuating the device. A dispensing area 6 is formed at the front end of the main section 3. The device 1 also has a connection 7 at the upper part of the main section 3, to which, for example, a hose or a container can be connected. The fluid to be applied can be supplied via the hose. Similarly, the fluid to be applied can be contained in the container.

[0067] The handle section 4 transitions at its end pointing away from the main section 3 into a foot 8, which may contain, for example, a power supply (e.g., a battery) for the device 1.

[0068] The device 1 according to the invention, which can also be referred to as the application device 1, is designed, in the embodiment described here, for the needle-free application of the fluid to an animal. The application preferably involves an intramuscular injection of the fluid, which may be, for example, a drug, a vaccine, or the like.

[0069] The application device 1 has a cylinder-piston arrangement 10 which will be described in detail below ( Fig. 3 and 4) and is designed as a self-filling type such that a piston movement towards the delivery area 6 causes the fluid to be ejected and an opposite movement of the piston causes the cylinder to be filled with the fluid for the next ejection process.

[0070] In Fig. 2 bis 5 The entire cylinder-piston assembly 10 is shown without the housing 2. The cylinder-piston assembly 10 comprises a front part 11 and an associated rear part 12. The front part 11 includes a cylinder 13 for receiving the fluid, which has an open discharge end 14 in which a check valve 15 is located, which is in fluid communication with a nozzle 16. The check valve 15 is also clearly visible in the illustration. Fig. 34 The system is designed to allow fluid to be discharged from cylinder 13 via the check valve 15 and the nozzle 16. It is not possible to draw in air or liquid through the nozzle and the check valve 15. The check valve 15 closes in this direction.

[0071] The front part 11 also has a connection 7 in which a further check valve 20 ( Fig. 3 ) is located, which allows a fluid connection from port 7 to cylinder 13 and blocks a fluid connection in the opposite direction. Port 7 has a channel 21 that opens into cylinder 13 via several radial bores 22.

[0072] The additional check valve 20 can therefore be referred to as an inlet valve and the check valve 15 as an outlet valve.

[0073] In cylinder 13, a piston rod 25 is guided with a piston 26 formed at its end pointing towards the open discharge end 14, wherein the piston 26 is shown in the sectional views of Fig. 3 and 4 in its rear end position. In this position, cylinder 13 is filled with the fluid to be discharged.

[0074] The rear end 27, which points the way from the open submission end 14 (good in Fig. 37 (to be recognized) the piston rod 25 is connected via a plate 28 to a first guide rod 29 and a second guide rod 30, which extend parallel to each other and parallel to the piston rod 25 and which are guided in the rear part 12 ( Fig. 4 ). The ends of the guide rods 29 and 30 pointing away from the plate 28 are connected to a driver 31.

[0075] Furthermore, a compression spring 32, 33 (e.g., a coil spring) is arranged for each guide rod 29 and 30, the front ends of which each bear against the plate 28 and the rear ends of which each bear against a stop 34 of the rear part 12. In the Fig. 3 and 4 In the position shown of the piston 26, the springs 32, 33 are tensioned.

[0076] At the rear end of the rear part 12, a cover 35 and a metering adjustment device 36 are provided, which are shown in the isometric view of the cylinder-piston arrangement 10 according to Fig. 6 The driver 31 is not shown, so that it is clearly visible. The driver 31 has a rotatably mounted roller 40, the axis of rotation of the roller 40 extending essentially perpendicular to the longitudinal axis of the piston rod 25.

[0077] The roller 40 runs on a ramp track 41 of a ramp 42 rotating under the roller 40, the ramp track 41 having a single turn, as shown in particular Fig. 6 bis 8 can be seen from this.

[0078] In Fig. 8 The rotation angle α is plotted relative to the pitch difference z parallel to the longitudinal direction of the piston rod 25, assuming that at a rotation angle of α0 = 0° the smallest pitch z0 is present and the piston 26 is thus in a forward end position in which its distance to the open discharge end 14 is minimal. This position of the piston 26 is shown, for example, in the sectional view according to Fig. 11 shown.

[0079] The ramp track 41 has a lower plateau 43, followed by a gradient section 44 that extends to the upper plateau 45. A transition section 46 adjoins the upper plateau 45, leading into a jump ramp 47 (rotation angle α1) that returns to the first plateau 43. Thus, the rotation angle range from α0 to α2 is 360°.

[0080] The jump ramp 47 is characterized by its near-vertical orientation, as it extends from height z1 to height z0 at a rotation angle (here α2). The transition zone 46 is therefore the rotation angle range in which the height z1 decreases continuously from the upper plateau 45 until the rotation angle α2 (= jump ramp 47) is reached. Thus, the rotation angle range from α1 to α2 covers the transition zone 46.

[0081] The ramp 42 is connected to a motor 51 via a coupling 50 ( Fig. 3 ), which rotates the ramp 42 in a first direction of rotation 52 ( Figuren 6 and 7 If the motor 51 now starts the ramp 42 from the one in Fig. 6 In the position shown, in which the cylinder-piston assembly 10 is tensioned, and continues to rotate in the first direction 52 (because a user has actuated the trigger 5), the roller 40 runs over the transition area 46 and then falls along the spring flank 47 towards the lower plateau 43, as the tensioned compression springs 32 and 33 accelerate the plate 28 towards the open dispensing end 14. This also moves the piston rod 25, which is connected to the plate 28, towards the front dispensing end 14, thereby dispensing the fluid contained in the cylinder 13 via the check valve 15 and the nozzle 16 for intramuscular injection in an animal. The application device 1 is designed so that the fluid reliably penetrates the skin and is applied to the underlying muscle. The piston 26 is then in its forward end position, as shown, for example, in the sectional view in Fig. 11 The application device 1 is preferably designed such that, in the forward end position of the piston 26, the driver 31 rests against the rear end of the rear section 12, with the rear end of the rear section 12 forming a stop for the driver 31. In this position, a desired minimum distance still exists between the roller 40 and the ramp track 41, so that the lower plateau 43 of the ramp track 41 is not reached by the roller 40. This prevents the roller 40 from striking the ramp track 41 at the end of the injection process, which could lead to damage to the roller 40.

[0082] After the injection process, the ramp 42 is rotated again in the first direction 52 by means of the motor 51, so that as soon as the roller 40 makes contact with the ramp track 41 in the incline area 44, further rotation causes the driver 31 to move away from the open dispensing end 14 along the longitudinal direction of the piston rod 25. This retensions the compression springs 32, 33, allowing them to reach their maximum tension when the roller 40 reaches the upper plateau 45. Due to the mechanical connection of the driver 31 with the guide rods 29 and 30, the plate 28, and the piston rod 25, this movement of the driver 31 also causes the piston rod 25, and thus the piston 26, to move away from the open dispensing end in the cylinder 13, thereby creating a vacuum.As soon as the built-up vacuum is so great that the inlet valve 20 opens, the fluid is drawn through the inlet valve 20 and the radial bores 22 into the cylinder 13, so that the cylinder 13 is filled with the fluid.

[0083] When the roller 40 (which can also be called cam or roller) has reached the upper plateau 45, the motor 51 stops, so that the cylinder-piston assembly 10 is tensioned and thus the application device 1 is ready for the next application operation, which can be carried out by actuating the trigger 5.

[0084] The plate 28, the springs 32, 33 together with guide rods 29, 30, the driver 31 with roller 40, the ramp 42 together with motor 51 and clutch 50 form a clamping device S for clamping the cylinder-piston assembly 10.

[0085] Furthermore, the application device 1 includes a control unit 54 for controlling the motor 51 and all other electrical components of the device 1. Fig. 3 A circuit board with control unit 54 is shown.

[0086] As previously described, the fluid is applied starting from the in Fig. 6 In the shown rotational position of ramp 42, the ramp is rotated further in the first direction of rotation 52, so that the roller 40 runs from the upper plateau 45 over the transition area 46 and is then accelerated along the jump flank 47 towards the lower plateau 53. However, the difficulty arises when crossing the transition area 46 ( Fig. 12A - 12C The spring force F of the tensioned springs 32, 33 has, in addition to a tangential component Ft, a perpendicular component Fs, which includes a component Fd that points in the same direction as the force of the motor Fm for rotating the ramp 42. This causes the roller 40 running over the transition area 46 to accelerate the rotation of the ramp 42 (in addition to the rotation caused by the motor 51). This can adversely affect the motor 51, causing it to act as a generator for this additional acceleration and producing a voltage peak that can damage the control electronics of the control unit 54. Furthermore, the motor 51 then acts as a brake, resulting in an undesirable braking effect during the rotation of the ramp 42, which undesirably alters the pressure profile during the application process.

[0087] Therefore, the coupling 50 is designed to transmit the torque provided by the motor 51 for rotating the ramp track 41 in the first direction of rotation 52 and simultaneously has a freewheel opposite the first direction of rotation 52, which is designed to cover at least the rotation angle range (from α1 to α2) that corresponds to the transition range 46 (here e.g. 7°).

[0088] To form the coupling 50, a star-shaped recess 61 is formed in a base 60 of the ramp 42 ( Fig. 13 The star-shaped recess 61 comprises a central section 62 and four arms 63 extending from it, each spaced 90° apart circumferentially. As in Fig. 13 schematically shown for one of the arms 63, the side surfaces 64, 65 of the arms 63 are inclined to each other, so that they enclose an angle β which corresponds at least to the rotation angle of the transition area 46 and thus here 7°.

[0089] Furthermore, the coupling 50 comprises a coupling part 66 connected to the motor, which has four star-shaped walls 67, each spaced apart from the others by 90° in the circumferential direction. A spring 69 (here a disc spring) is arranged on each side surface 68 of each wall. The springs 69 serve to support the movement and to dampen it. The walls 67 of the star-shaped contour of the coupling part 66 are inserted into the star-shaped recess 61 of the base 60 of the ramp 42, as shown in the front view. Fig. 17 As shown. Due to the springs 69, each wall 67 is centered in the corresponding arm 63 of the star-shaped recess 61 when no torque is transmitted via the clutch 50.

[0090] When the roller 40 is rotated in the first direction of rotation 52 by means of the motor 51, the front side surfaces 68 seen in the first direction of rotation 52 lie against the corresponding side surface 64 of each arm 63, as shown in Fig. 18 shown.

[0091] When the roller 40, starting from the upper plateau 45, passes over the transition area 46, the ramp 42 is additionally accelerated in the first direction of rotation 52 due to the described spring force (here the component Fd), so that, due to the provided freewheel, the ramp 42 can rotate faster in the first direction of rotation 52 than the coupling part 66 connected to the motor 51. This freewheel ends as soon as the rear side surface 68 of the respective wall 67, as seen in the first direction of rotation 52, abuts the side surface 65 of the corresponding arm 63 of the star-shaped recess 61, as shown in Fig. 19 As shown. Since the freewheel is designed to cover at least the entire transition area 46, the roller 40 is moved beyond the entire transition area 46 as soon as the contact according to Fig. 19 This allows the roller 40 to move freely along the jump flank 47 and reliably prevents the undesirable acceleration of the rotary motion of the motor 51 when crossing the transition area 46.

[0092] In Fig. 20 A schematic front view is shown, illustrating the spatial arrangement of springs 32 and 33 and the motor 51. The two springs 32 and 33 are connected in parallel via the plate 28, so that their spring rates (spring constants) add up. This allows the necessary force (spring force) to be provided when the piston 26 is in its rear end position, enabling the intramuscular administration of the delivered fluid in an animal. Simultaneously, the required installation space for the cylinder-piston assembly 10 can be kept small and compact. As a comparison with the illustration in Fig. 21 As shown, where only one spring 32' is provided instead of the two springs 32 and 33, this would lead to a larger installation space for the corresponding cylinder-piston arrangement 10', since this single spring 33' would have to have a larger diameter to provide the same spring force.

[0093] Of course, it is also possible to connect more than two springs 32 and 33 in parallel. As shown in the schematic diagrams of Fig. 22 und 23 As can be seen, for example, three or four springs 32, 33, 37 and optionally 38 can be provided to achieve a compact design. The more than two (here three or four) springs can preferably be arranged symmetrically to the motor 51, as shown in Fig. 22 und 23 shown.

[0094] As already explained, the front part 11 and the rear part 12 are two separate parts that are connected to each other, as can be clearly seen in the illustrations in Fig. 24 and 25 can be seen from this.

[0095] Preferably, the front part 11 and the rear part 12 are made of different materials. Since the front section of the front part 11 protrudes from the housing 2 ( Fig. 1 ), a material is chosen for this purpose which, for example, has a higher strength than the material for the rear part and / or has better media resistance than the material of the rear part 12.

[0096] The material of the front part can be titanium, steel or plastic (e.g. PEEK).

[0097] For the rear section 12, a material is chosen that is as lightweight as possible. Aluminum, magnesium, titanium, or plastic are preferred.

[0098] The dosing adjustment device 36 comprises, as shown in particular in the enlarged detailed section view in Fig. 26 as well as Fig. 27A As can be seen, a spacer 70, into which a threaded rod 71 is screwed, is coupled via a first and second gear 72, 73 to a shaft 74 of a second motor 75. The threaded rod 71 is in a threaded bore 76 in the spacer 70 ( Fig. 3 ) screwed in. Furthermore, the spacer 70 comprises two laterally projecting guide webs 77, 78 ( Fig. 27A The guide ribs 77, 78 are guided in guide grooves 79 of the cover 35. The guide grooves 79 are best in Fig. 28 recognizable. Furthermore, the cover 35 includes an opening 80 through which the spacer 70 can be moved.

[0099] In the representation according to Fig. 3 The spacer 70 is in its neutral position, in which it does not influence the return movement of the roller 40 and thus of the driver 31 from the upper plateau 45 via the transition area 46 along the jump flank 47 to the lower plateau 43. Fig. 26 The spacer 70, on the other hand, has been moved into its active position, in which it is positioned between the driver 31 and the rear end of the rear part 12 such that it forms a stop for the driver 31. The movement of the spacer from the in Fig. 3 position shown in Fig. 26 The position shown is generated by a rotation of shaft 74, whereby, for example, a clockwise rotation of shaft 74 results in a movement from the position shown. Fig. 3 position shown in Fig. 26 The position shown and a counterclockwise rotation of the shaft 74 causes an opposite movement. Of course, the metering adjustment device 36 can also be designed so that the reverse directions of rotation produce the same movements. The essential point here is that the second motor 75 can rotate the two gears 72 and 73, and thus the shaft 74, in order to convert this rotational movement into a translational movement of the spacer 70 perpendicular to the longitudinal direction of the piston rod 25. This allows the spacer 70 to be moved back and forth between its active position and its neutral position.

[0100] If the spacer 70 is now in the Fig. 26 In the active position shown, the movement of the driver 31 in the longitudinal direction of the piston rod 25 is shortened after the roller 40 has passed over the transition area 46, since this movement now ends when the driver 31 rests against the spacer 70. The extension of the spacer 70 along the longitudinal direction of the piston rod 25 thus corresponds to the shortening of the piston stroke when applying the fluid located in the cylinder 13. This allows a smaller quantity of fluid to be dispensed, enabling the application device 1 to administer two different dosages (here, for example, 2 ml and 1 ml). If the dosage is to be changed, the spacer 70 simply needs to be moved into its position when the roller 40 is at the upper plateau 45. Fig. 26 The shown active position will be brought into play.

[0101] The spacer 70 is designed such that when the driver 31 rests against it, the roller 40 does not make contact with the spacer 70. This prevents the roller 40 from being damaged when the driver 31 is stopped by the spacer 70.

[0102] Using the described spacer according to Fig. 27A It is therefore possible to set a single, lower dosage, as described. Fig. 27B A modification of the spacer 70 is shown, with which it is possible to set two different lower dosages, since the spacer 70 has a first stop area 140A and a second stop area 141A, which are defined by the extension of the spacer 70 along the first direction (in Fig. 27B (from left to right). Since this extension corresponds to the reduction in the piston stroke of piston 26 during the application process, two different reductions in dosage are possible. If the spacer 70 is retracted so far between the driver 31 and the rear end of the rear section 12 that the driver 31 is stopped by section 140A during the application process, a first reduction in the piston stroke occurs. If, on the other hand, the spacer 70 is retracted so far that the driver 31 rests against area 141A during the application process, then a second reduction in the piston stroke occurs, which is greater than the reduction caused by section 140A. This stepped design of the spacer 70 thus makes it possible to set two different reductions in dosage.

[0103] To move the spacer 70 between its neutral position and its active position, the motor 75 is, in the simplest case, activated for a predetermined time, during which it rotates the threaded rod 71. For example, a stop can be provided for both the active and neutral positions, against which the spacer moves. A disadvantage of this design is that the threaded rod 71 can become jammed in the threaded bore 76, and the motor 75 may not be able to supply sufficient force or torque to free it when the spacer 70 is moved in the opposite direction.

[0104] Therefore, according to a further embodiment, the spacer 70 can be Fig. 27C As shown, instead of the threaded bore 76, a through bore 140 with smooth side walls is provided, as shown in the sectional view in Fig. 27D shown is the section AA of the spacer 70 according to Fig. 27C shown. Furthermore, a spring-loaded pressure piece 141 (or spring-loaded pin 141) is provided, which, as shown in the sectional view in Fig. 27D It can be seen that it engages in a spindle thread 142 of a spindle 143, which is provided instead of the threaded rod 71.

[0105] The spring-loaded pin 141 is designed to be pressed against the spindle thread 142.

[0106] The spindle thread 142 is designed such that it terminates in a straight groove 144, 145 at both ends. The straight grooves 144, 145 are characterized by the fact that they have no thread pitch, but rather, viewed in the longitudinal direction of the spindle 143, always have the same height.

[0107] Since the pressure piece 141 engages in the spindle thread 142, rotation of the spindle 143 causes the spacer 70 to move upwards or downwards (i.e., back and forth between the neutral position and the active position). When the end of the spindle thread 142 is reached, the pressure piece 141 runs into the corresponding straight groove 144, 145, so that no further axial movement of the spacer 70 is generated. Only the spindle 143 continues to rotate.

[0108] Preferably, the straight grooves 144, 145 are designed to have a shallower depth than the spindle thread 142.

[0109] If the direction of rotation of the spindle 143 is reversed, the pressure piece 141 (due to the spring preload) falls securely into the deeper spindle thread 142 and the spacer 70 is thus moved in the opposite direction until the pressure piece 141 engages in the other straight groove 145, 144 and thus further rotation of the spindle 143 does not result in any further axial movement.

[0110] In this way, jamming of the spindle 143 in the spacer 70 can be reliably prevented. Furthermore, simple motor control is possible, as the motor 75 only needs to be controlled to drive the spindle 143 for a sufficient duration. Due to the respective straight grooves 144 and 145, free movement is ensured, allowing further rotation of the spindle 143 without axial movement of the spacer 70.

[0111] The spindle 143 can be described as a spindle with freewheel.

[0112] For example, in Fig. 28 As can be clearly seen, the cover 35 comprises a first, second and third scraper 80, 81, 82 which, in the assembled state according to Fig. 3 , extending from a rear end of the cover 35 towards the dispensing end of the application device 1. For example Fig. 28 As can be seen, the wipers 80-82 are formed on a frustoconical central part 83 and are spaced apart from each other in the circumferential direction. The frustoconical central part 83 tapers towards the discharge end, as shown in Fig. 3 as is evident.

[0113] In the assembled state, the frustoconical central section 83 extends to the base 60 of the ramp 41. Similarly, the first scraper 80 extends to the base 60. In a radial direction, the first scraper 80 extends to the inner side 84 of the wall 85, on the end face of which the ramp track 42 is formed ( Fig. 6 ).

[0114] The second wiper 81 is shorter than the first wiper 80 in both the axial and radial directions. Similarly, the third wiper 82 is shorter than the second wiper 81 in both the radial and axial directions.

[0115] Furthermore, the cover 35 includes an intermediate wall 86 in which an axially extending slot is formed, allowing the roller 40, together with its mounting section of the driver 31, to move axially. Otherwise, the intermediate wall 86, together with the lower cover part 88, surrounds the outer surface 89 of the wall 85 in the assembled state. A lubricant (for example, grease) is provided in this remaining space between the cover 35 and the wall 85. This lubricant ensures that the roller 40 rotates as smoothly as possible and is guided on the ramp track 41 with minimal friction. The wipers 80 to 82, due to the relative movement between the ramp track 41 and the wipers 80-82, move any grease that does not remain on the ramp track 41 back towards the ramp track and roller 40, thus ensuring continuous lubrication.The lubricant that accumulates at the bottom of the cover 35 is thus conveyed back to the ramp track 41 and to the roller 40, ensuring the desired permanent lubrication.

[0116] In Fig. 34 Figure 1 shows an enlarged sectional view of the front part 11 including piston 26 and part of the piston rod 25. The cylinder 13 has an annular groove 90 in its rear region (away from the open discharge end 14), in which an O-ring 91 or a sealing ring 91 (e.g., an elastomer seal) is inserted for sealing. Furthermore, a first and a second support ring (92, 93) are arranged in the groove 90 such that the sealing ring 91 is positioned between the two support rings 92 and 93. The groove 90 and the support rings 92 and 93 are dimensioned such that the gap between the support rings 92 and 93 and the piston rod 25 is smaller than the gap between the inside of the cylinder 13 and the piston rod 25. The support rings, which can be made of PTFE or other plastics, reliably prevent part of the sealing ring 91 from being dislodged due to the pressure built up during movement of the piston rod 95.The vacuum is extruded into the gap between the piston rod 25 and the inside of the cylinder 13, which would destroy the sealing ring 91.

[0117] The second support ring 93 prevents the described gap extrusion when the piston rod 25 moves towards the open dispensing end 14, and thus when the fluid is applied. The first support ring 92 prevents the undesired gap extrusion during the opposite movement, and thus when the cylinder 13 is filled with the fluid.

[0118] As in Fig. 34 As can be seen, the nozzle 16 has a tapered through-bore 95 through which the fluid is dispensed during application. The necessary through-bore 95 can also be formed in an insert 96, as shown in Fig. 35 shown, which is then to be screwed into the remaining nozzle base body 97. The insert 96 comprises a base body 98 with an external thread, which includes a receiving area 99 at its distal end. A sapphire element 100 is inserted into the receiving area 99, in which the last section of the through-bore 95 is formed. As shown in the illustration in Fig. 35 As can be seen from the base body 98, the diameter of the last section of the through-hole 95 is the smallest, or smaller than the diameter of the sections of the through-hole 95 formed in the base body 98. This advantageously ensures that the necessary very small diameter of the through-hole 95 at its distal end can be reliably produced, since the section of the through-hole 95 in the sapphire element 100 can be manufactured more precisely than a bore in the base body 98, which is made of metal. The diameter of the last section of the through-hole 95 in the sapphire element 100 can, for example, be in the range of 0.30 to 0.38 mm, with a manufacturing tolerance of no more than 0.02 mm.

[0119] Since the unit consisting of piston rod 26, plate 28, and guide rods 29, 30 is relatively long and high forces act during fluid application, it must be ensured that the piston rod 26 can move freely within the cylinder 13 and does not, for example, become jammed. To this end, the piston rod 26 should be aligned as parallel as possible to the guide rods 29, 30, and this alignment should be maintained over extended periods of use of the application device 1.

[0120] Therefore, the piston rod 25 is not rigidly connected to the plate 28. The connection is designed to allow the piston rod 25 to tilt or rotate relative to the plate 28. The piston rod 25 is thus connected to the plate 28 via a pivot joint. As shown in the illustrations in Fig. 36 and 39As can be seen, a first washer 110 is provided between the rear end 27 of the piston rod 25 and the plate 28. Furthermore, a fixing screw 111, which passes through a corresponding bore in the plate 28, is screwed into the rear end 27. A second and a third washer 113, 114 are arranged between a head 112 of the fixing screw 111. To provide the desired rotatability, the rear end 27 is rounded (here, for example, spherical), and the side of the first washer 110 facing the rear end 27 is correspondingly concave, so that this side forms a bed for the rear end 27. As shown in the illustration in Fig. 37 As can be seen, the first washer 110 sits in a recess in the plate 28, so that the first washer 110 cannot move transversely to the longitudinal direction of the piston rod 25. The side of the first washer 110 facing away from the rear end 27 is flat, since the corresponding base of the recess in the plate 28 is also flat. Thus, the first washer can also be described as concave-flat.

[0121] The second and third washers 113 and 114 are designed such that their facing sides are curved. The side of the second washer 113 facing the third washer 114 has a convex curvature. The side of the third washer 114 facing the second washer 113 is correspondingly concave. The other sides of the second and third washers 113 and 114 are flat. The head 112 of the fixing screw 111 presses the third washer 114 onto the second washer 113, which is thereby pressed against the side of the plate 28 facing away from the rear end 27. The second washer 113 is thus plano-convex, and the third washer 114 is thus concave-plan.

[0122] Due to the selected dimensions and curvatures, the pivot point 115 for the rotation of the piston rod 25 relative to the plate 28 is spaced apart from the plate 28 and on the side of the screw head 112.

[0123] Since the described connection allows the piston rod 25 to rotate relative to the plate 28, it can be ensured that the piston rod 25 can always be moved in the cylinder 13 without jamming.

[0124] The motor 51 can be designed as an electric motor, and in particular as a brushless electric motor. This improves the durability of the application device 1, since with electric motors with brushes, the problem can arise that the brushes can break due to the vibrations that occur during the application of the fluid.

[0125] To detect whether fluid is present in cylinder 13 during the in Fig. 3 In the position of the piston 26 shown, a sensor 55 is provided, which in the embodiment described here is located upstream of the further check valve 20 (which can also be referred to as the inlet valve). The sensor 55 can, for example, distinguish between air and liquid, thus preventing the application device 1 from performing an application process when no liquid is present in the cylinder 13. This prevents damage to the application device 1, as it is designed so that the liquid dampens the movement of the piston rod 25 or the piston 26 during application towards the open dispensing end. If there is no liquid in the cylinder 13, this damping function is lost, which can lead to mechanical damage, e.g., to the piston rod 25, the connection of the piston rod 25 to the plate 28, or to the guide rods 29, 30.The sensor 55 can be designed as a voltage sensor, as a capacitive sensor or, for example, as a light barrier.

[0126] Housing 2 can have a luminous area of ​​120 ( Fig. 1 ), which can illuminate in different colors. Area 120 can, for example, be strip-shaped or have any other form. The different colors can be used to communicate information to the user about the status of the application device 1. For example, a first color (e.g., red) can indicate to the user that the device 1 is not ready for use. A second color can indicate that it is generally ready for operation. A third color can indicate that the cylinder-piston assembly 10 is cocked and that an application process can be carried out by pressing the trigger 5. A fourth color (e.g., green) can indicate to the user that the application process was successful. Furthermore, another color can indicate to the user that an error condition exists.Of course, the described information can be communicated not only through different colors, but also through the same colors, if the differences are represented, for example, by different blinking patterns. Furthermore, it is possible to provide the user with haptic or auditory feedback instead of this described visual feedback. Naturally, visual, haptic, and auditory feedback can also be combined.

[0127] Furthermore, the application device 1 can have an acceleration sensor 130, which is shown by way of example only in Fig. 3 is shown. Since the measured acceleration values ​​for a correct application process differ from those of an incorrect application process, the measured values ​​can be used to determine whether an application process was successful or not. Fig. 38 The measured acceleration values ​​for a successful application process are plotted along the y-axis in g (acceleration due to gravity) against time along the x-axis (in ms). The measured acceleration values ​​are represented as points connected by a line. A test curve is shown as a dashed line. If the acceleration values ​​are below the values ​​of the test curve, it is determined that the application process was successful.

[0128] In Fig. 39 An example of an application process (hereinafter also referred to as a shot) is shown, which was unsuccessful. The acceleration values ​​exceed the maximum value of the test curve, so the shot is considered unsuccessful.

[0129] Furthermore, the current consumption of motor 51 can be measured and evaluated to assess the quality of the shot.

[0130] In Fig. 40 The measured current consumption for the loading and firing process of application device 1 is shown, with the measured current values ​​in A (= amperes) plotted as points connected by a line. The current value is plotted along the y-axis (and over time in ms along the x-axis). A successful loading and firing process occurs when the measured current values ​​are less than the upper limit curve and greater than the lower limit curve (both curves are shown with dashed lines).

[0131] In the case of an unsuccessful shot, the measured current consumption lies outside the range limited by the two limit curves, as shown in Fig. 41 This is shown. In this case, the application process was unsuccessful.

[0132] Instead of or in addition to the accelerometer 130, a sensor 131 for measuring sound or tones (e.g. a microphone) can be provided, which is schematically shown in Fig. 3This is illustrated. The pitches measured during the application process can be used to determine, for example, whether the application was successful. If the measured pitch exceeds a predefined upper limit, or if the measured pitch falls below a predefined upper limit, the application is considered unsuccessful. Similarly, the measured pitch may fall below a predefined lower limit, indicating a faulty application. A measured frequency spectrum can also be used as a parameter, provided it meets a specified target profile for the application to be considered successful. Likewise, the intensity (or volume) profile can be used as a parameter, which must also meet a specified target profile.

[0133] Of course, several of the described parameters can also be used to evaluate the application process. For example, only the dispensing process, only the clamping process, or clamping and dispensing processes together can be measured and evaluated.

[0134] The control unit 54 can perform the described measurement and evaluation of the parameters to determine whether the application process was successful or not. Depending on the decision, the control unit can, for example, generate optical, haptic, and / or acoustic feedback in the manner described.

Claims

1. A device for administering a fluid, comprising a cylinder (13), which has an open dispensing end (14), a piston (26), which is displaceable in the cylinder (13) between a front end position and a rear end position and is connected to a piston rod (25) which, along a first direction, protrudes from a rear end of the cylinder (13) opposite the open dispensing end (14), a nonreturn valve (15) closing the open dispensing end, and a tensioning device (S) connected to the piston rod (25); wherein the tensioning device (S) can move the piston rod (25) along the first direction in a tensioning procedure until the piston (26) is in its rear end position, in order thereby to fill the cylinder (13) with the fluid to be administered and to pretension the piston rod (25) toward the open dispensing end (14), and wherein the tensioning device (S), when the piston (26) is in its rear end position, can release the piston rod (25) in a dispensing procedure such that, owing to the pretension which is present, the piston (26) is moved counter to the first direction toward the open dispensing end (14) and, in the process, fluid in the cylinder (13) is dispensed via the nonreturn valve (15) for administration, the tensioning device (S) has a ramp (42) which is rotatable by means of a motor (51) and has a ramp track (41) extending along a helical line, wherein the ramp track (41) ascends from a first plateau (43) along a region of inclination (44) to a second plateau (45) and descends from the second plateau (45) to the first plateau (43) via a transition flank (47), wherein the ramp track has a transfer region (46) connecting the second plateau (45) and the transition flank (47), wherein the tensioning device (S) moreover has a roller (40) which is in contact with the ramp track (41) and which is mounted rotatably in a driver (31), the latter being connected to the piston rod (25), and therefore, upon rotation of the ramp (42) along a first rotation direction (52), the ramp track (41) runs below the thus rotating roller (40), wherein, for the tensioning procedure, the ramp track (41) is rotated along the first rotation direction (52) such that the roller (40) runs on the region of inclination (44) as far as the second plateau (45) and the piston (26) is thereby moved to its rear end position, wherein, for the dispensing procedure, starting from a contact of the roller (40) with the second plateau (45), the ramp track (41) is rotated along the first rotation direction (52) until the roller (40) runs over the transfer region (46) and, on account of the tensioning, is accelerated toward the first plateau (43) and, as a result, the piston (26) is moved toward the open dispensing end (14), characterized in that a dose setting means (36) is provided which comprises a spacer (70) and a movement unit, wherein the movement unit can move the spacer (70), when the piston (26) is in its rear end position, from a neutral position, in which the spacer (70) is not positioned between the driver (31) and the cylinder (13), into an active position between the driver (31) and the cylinder (13) such that the driver (31), after the roller (40) has run over the transfer region (46), is stopped by the spacer (70) and therefore the piston stroke during the movement of the piston (26) to the open dispensing end is shorter in comparison to the case in which the spacer (70) is in its neutral position, wherein the spacer (70) has a through bore (140) in which a spindle (143) with a spindle thread (142) is guided, wherein the spacer (70) has a pin (141) which protrudes into the spindle thread (142), and wherein the spindle thread (142) leads at at least one of its two ends into an annular groove (144, 145).

2. The device as claimed in claim 1, in which the spindle thread (142) leads at its two ends into an annular groove (144, 145).

3. The device as claimed in claim 1 or 2, in which the depth of the annular groove (144, 145) or the depth of the annular grooves (144, 145) is smaller than the depth of the spindle thread (142).

4. The device as claimed in one of the preceding claims, in which the spindle thread (142) is a single-start thread.

5. The device as claimed in one of claims 1 to 3, in which the spindle thread (142) is a multi-start thread.

6. The device as claimed in one of the preceding claims, in which the pin (141) is designed as a spring-pretensioned pin (141).

7. The device as claimed in one of the preceding claims, in which the spindle thread (142) is rotated by means of a motor (75) of the movement unit in order to move the spacer (70) between its neutral position and its active position.

8. The device as claimed in one of the preceding claims, wherein the spacer (70) is guided in such a manner that the spacer (70) is movable only in a plane perpendicular to the piston rod (25).

9. The device as claimed in one of the preceding claims, in which the spacer (70) is designed in such a manner that, when the driver (31) is stopped by the spacer (70), the roller (40) is not in contact with the spacer (70).

10. The device as claimed in one of the preceding claims, wherein the spacer (70) has a first abutment region (140A) and a second abutment region (141A) for the driver (31), wherein the extent of the spacer (70) along the first direction is smaller for the first abutment region (140A) than for the second abutment region (141A), and therefore different shortenings of the piston stroke can be set, depending on whether the first or second abutment region (140A, 141A) is moved into the active position of the spacer (70).

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