Device for applying fluid

Abstract

The device for supplying fluid includes a cylinder (13) having an open supply end (14), a piston (25) connected to a piston rod that protrudes from the rear end of the cylinder in a first direction, a first valve that closes the open supply end, a supply passage connected to the cylinder, and a second valve (20) that closes the supply passage. When the valve (20) is open, the fluid to be supplied can enter the cylinder through the supply passage. The movement of the piston toward the open supply end generates a positive pressure in the cylinder, such that when the first valve is open, the fluid to be supplied is supplied via the open supply end. A first sealing element (61) is arranged between the piston and the cylinder, and a second sealing element (62) is arranged spaced apart from the first sealing element in a first direction. The first sealing element is a single-acting sealing element that seals the rear end of the cylinder with respect to positive pressure in the cylinder, and the second sealing element is a single-acting or double-acting sealing element that seals the rear end of the cylinder with respect to negative pressure in the cylinder.

Description

Technical Field

[0001] The present invention relates to a device for administering fluids, which may be designed, for example, as a needle-free self-filling syringe, through which liquid agents, liquid pharmaceutical products, liquid vaccines or the like may be administered to animals (especially via intramuscular administration). Background Technology

[0002] Such a device for administering fluids should be as light as possible, and thus be able to be held by the user in one hand for an extended period of time, while also allowing for the desired injection (especially needle-free intramuscular injection). Summary of the Invention

[0003] Therefore, the object of the present invention is to provide such a device for applying fluid.

[0004] Since the device for supplying fluid according to the invention has a first sealing element designed as a single-acting sealing element and a second sealing element spaced apart from the first sealing element and designed as a single-acting or double-acting sealing element, a good seal can be provided at the rear end of the cylinder with respect to high dynamic pressure and negative pressure. Thus, the first sealing element provides a seal at the rear end of the cylinder with respect to positive pressure, which occurs when fluid is supplied. Furthermore, the arrangement of the second sealing element has the effect of sealing the rear end of the cylinder with respect to negative pressure within the cylinder, which occurs when new fluid is drawn in for the next supply process.

[0005] Therefore, it can be said that a series of seals are provided, which are optimized to seal the rear end of the cylinder with respect to positive pressure (by means of the first sealing element) and with respect to negative pressure (by means of the second sealing element).

[0006] Here, the single-acting first sealing element is specifically understood as a sealing element that seals the rear end of the cylinder with respect to positive pressure in the cylinder but not with respect to negative pressure in the cylinder (and therefore positive pressure outside the rear end of the cylinder). Thus, only the positive pressure in the cylinder is sealed with respect to the rear end.

[0007] A single-acting second sealing element is particularly understood as a sealing element that seals the rear end of the cylinder with respect to negative pressure in the cylinder (and therefore positive pressure outside at the rear end). Here, a double-acting second sealing element (or two-acting second sealing element) is particularly a sealing element that seals the rear end of the cylinder with respect to both positive and negative pressure in the cylinder.

[0008] The first sealing element may in particular have a U-shaped or V-shaped cross-section, wherein the opening of the U-shaped or V-shaped cross-section points in the direction of the opening feeding end.

[0009] In addition, the first sealing element may have a tensioning device (e.g., a spring) that compresses the two arms of the U-shaped or V-shaped cross-section to be radially separated from each other.

[0010] The material used for the first sealing element can be a plastic, polymer, fluoropolymer, polyurethane (e.g., injection-molded or cast polyurethane), elastomer, or PTFE (polytetrafluoroethylene). These materials may contain fillers (e.g., carbon fiber or glass fiber) and / or additives to adjust the desired properties of the sealing element. Therefore, the first sealing element can be made of PTFE or a mixture of PTFE. A PTFE mixture is particularly understood as a mixture of PTFE with at least one other substance (e.g., carbon, carbon fiber, carbon black, glass fiber, organic filler, metal, metal alloy, etc.). If a spring is provided, the spring is preferably made of metal.

[0011] The first sealing element may have an annular sealing member, and a spring element subjecting the annular sealing member to radially inward tension. Therefore, the annular sealing member can be subjected to radially inward pretension in the installed state.

[0012] The annular sealing component can be made of thermoplastic, and the spring element can be made of elastomer. The spring element, in particular, can be designed as an O-ring.

[0013] The second sealing element can be designed in the same way as the first sealing element. The second sealing element is then arranged at 180° relative to the first sealing element (the opening of the U-shaped or V-shaped cross section points away from the mating end of the opening and thus towards the rear end of the cylinder) to ensure the desired seal of the rear end of the cylinder with respect to the negative pressure in the cylinder.

[0014] Alternatively, the second sealing element may be designed as a double-acting sealing element. In this case, the second sealing element could be designed as an O-ring, for example.

[0015] The same material used for the first sealing element can be used for the second sealing element. For example, an elastomer (e.g., a fluoropolymer), PTFE, or a PTFE mixture can preferably be used.

[0016] The first and second sealing elements can be arranged or mounted on the cylinder body such that the piston moves relative to the sealing elements. In this arrangement, the sealing elements are typically referred to as rod seals.

[0017] Alternatively, the first and second sealing elements may be fixed to the piston, allowing the piston to move together with the sealing elements within the cylinder. In this arrangement, the sealing elements are typically referred to as piston seals.

[0018] Furthermore, it is possible to provide a lubricating ring spaced apart from the second sealing element along the first direction. The lubricating ring can be designed as a felt ring or formed of a sponge-like material. Additionally, the lubricating ring can be coated with oil or grease. This ensures good lubrication of the piston during its movement within the cylinder.

[0019] The cylinder block can be designed as one component or multiple components, and particularly two components. In this case, the cylinder block may include a rear cylinder block component, the rear end of which forms the rear end of the cylinder block. A first sealing element and a second sealing element may be arranged in the rear cylinder block component. Furthermore, if a lubrication ring is provided, the lubrication ring may also be arranged in the rear cylinder block component.

[0020] The rear cylinder block component can be connected to another component of the cylinder block (e.g., the front cylinder block component). This connection can be, for example, a releasable connection. For instance, the connection can be configured as a snap-fit ​​closure or a threaded connection.

[0021] The movement of the piston within the cylinder can be manual or motorized. A motor can be provided that performs both movement of the piston away from the open feeding end and movement of the piston toward the open feeding end. Alternatively, the motor can only generate movement of the piston away from the open feeding end, in which case the tensioning unit of the tensioning device (e.g., one or more springs) is tensioned. During the application process, the tensioning unit is released, such that the tensioning energy is converted into movement of the piston toward the open feeding end. In this way, high pressure can be established, which is particularly desirable for needleless application of fluids.

[0022] The tensioning device may have a ramp that can be rotated by a motor and has a ramp path extending along a spiral, wherein the ramp path rises from a first platform to a second platform along an inclined region and descends from the second platform to the first platform via a transition side, wherein the ramp path has a transfer region connecting the second platform and the transition side. Furthermore, the tensioning device may include a roller that contacts the ramp path and is rotatably mounted in a driver connected to a piston rod, so that once the ramp rotates along a first direction of rotation, the ramp path operates beneath the rotating roller. For the tensioning process, the ramp path can rotate along the first direction of rotation, causing the roller to run along the inclined region to the second platform, and the piston thereby moves to its rear end position, where the tensioning unit is tensioned. For the feeding process, starting from the contact between the roller and the second platform, the tensioning device can rotate the ramp path along the first direction of rotation until the roller passes the transfer region and, due to the tensioned tensioning unit, accelerates towards the first platform, thereby causing the piston to move towards the open feeding end.

[0023] The device according to the invention is preferably designed as a self-filling syringe. Here, a self-filling syringe is particularly understood as a syringe in which, during or due to the movement of the piston away from the dispensing end of the syringe, the fluid to be administered is drawn into the cylinder, and wherein the fluid to be administered is dispensed by means of the movement of the cylinder toward the dispensing end. The device according to the invention is preferably designed as a self-filling syringe for needle-free administration (especially intradermal, subcutaneous, or intramuscular administration) to animals and / or humans.

[0024] Of course, the device according to the invention can also be designed as a self-filling syringe with a needle at the dispensing end.

[0025] The first valve can be designed as either a passive or active valve. Similarly, the second valve can also be designed as either a passive or active valve. Here, a passive valve is specifically understood as one whose opening and closing are achieved by positive or negative pressure generated in the cylinder due to the movement of the piston within the cylinder. An active valve is specifically understood as a valve that can be opened and closed by means of an actuator. Here, an open first or second valve is specifically understood as indicating the presence of a desired fluid connection between the cylinder and the feeding end or supply passage. A closed first or second valve is specifically understood as indicating the absence of a fluid connection between the cylinder and the feeding end or supply passage (or that the desired fluid connection is interrupted or blocked when the valve is open). The first valve can be designed as a check valve. Furthermore, the second valve can be designed as a check valve.

[0026] The device can be designed such that the movement of the piston in the first direction generates a negative pressure in the cylinder, and thus, when the second valve opens, the fluid to be supplied is drawn into the cylinder through the supply passage. In particular, the generated negative pressure can open the second valve. Furthermore, the positive pressure in the cylinder generated by the movement of the piston in the opposite direction to the first direction toward the open dispensing end can open the first valve, thereby dispensing the fluid to be supplied from the cylinder through the open dispensing end.

[0027] It should be understood that the features described above and those explained below can be used not only in the specified combinations, but also in other combinations or individually, without departing from the scope of the invention. Attached Figure Description

[0028] The invention will now be explained in more detail based on exemplary embodiments with reference to the accompanying drawings, which also disclose features essential to the invention. These exemplary embodiments are illustrative only and should not be construed as limiting. For example, the description of exemplary embodiments having multiple elements or components should not be construed as indicating that all such elements or components are necessary for implementation. Rather, other exemplary embodiments may include alternative elements and components, fewer elements or components, or additional elements or components. Unless otherwise stated, elements or components of different exemplary embodiments may be combined with each other. Modifications and variations described with respect to one exemplary embodiment may also apply to other exemplary embodiments. To avoid repetition, the same elements or corresponding elements in different drawings are denoted by the same reference numerals and will not be explained repeatedly. In the figures:

[0029] Figure 1 A perspective view of an exemplary embodiment of the application device 1 according to the present invention is shown;

[0030] Figure 2 A front view of the cylinder / piston assembly 10 of the application device 1 is shown;

[0031] Figure 3 The cylinder / piston assembly 10 is shown along... Figure 2 A sectional view of section line AA in the diagram;

[0032] Figure 4 The cylinder / piston assembly 10 is shown along... Figure 3 A sectional view of section line BB in the diagram;

[0033] Figure 5 The cylinder / piston assembly 10 is shown along... Figure 4 A sectional view of section line CC in the diagram;

[0034] Figure 6 An isometric view of the cylinder / piston assembly 10 is shown, wherein the assembly is tensioned and the piston is in its rear end position;

[0035] Figure 7 An isometric view of the cylinder / piston assembly 10 is shown, with the piston in its front-end position;

[0036] Figure 8 A diagram is shown that shows the outline of ramp track 41, with the rotation angle α plotted along the x-axis and the stroke plotted along the longitudinal axis of piston rod 27 on the y-axis.

[0037] Figure 9 It shows that it is based on Figure 6 A cross-sectional view of the cylinder / piston assembly 10 in its tensioned state;

[0038] Figure 10 A side view of the cylinder / piston assembly 10 with the piston in its front end position is shown;

[0039] Figure 11 The cylinder / piston assembly 10 is shown along... Figure 10 A sectional view of section line DD in the diagram;

[0040] Figure 12 An enlarged cross-sectional view of the front component 11 is shown;

[0041] Figure 13 It shows that according to Figure 12 A magnified detail image of detail E, in which, with Figure 12 Compared to the view in the image, piston 25 is positioned closer to the opening feeding end 14;

[0042] Figure 14 An enlarged view of the annular cross-section in an embodiment of the first sealing element 61 is shown; and

[0043] Figures 15 to 18 An enlarged view of the annular cross-section of another embodiment of the first sealing element 61 is shown. Detailed Implementation

[0044] exist Figure 1 In the exemplary embodiment shown, the device 1 for dispensing fluid (e.g., liquid) according to the present invention includes a housing 2 having a main portion 3 and a handle portion 4. The handle portion 4 is designed so that a user can hold the device 1 by gripping the handle portion 4. Furthermore, the handle portion 4 has a trigger 5 for actuating the device 1. A dispensing region 6 is formed at the front end of the main portion 3. Additionally, in the top region of the main portion 3, the device 1 has an attachment 7 to which a hose or container can be connected. The fluid to be dispensed can be delivered via the hose. Similarly, the fluid to be dispensed can be held in the container.

[0045] The handle portion 4 transitions into the base 8 at its end away from the main portion 3, for example, the power source for the device 1 (e.g., a battery) may be contained in the base 8.

[0046] In the exemplary embodiments described herein, the device 1 according to the invention (also referred to as the administering device 1) is designed for administering fluid to an animal without needles. The administration preferably involves intramuscular injection of the fluid, which may be, for example, a pharmaceutical product, a vaccine, or the like.

[0047] The application device 1 has a cylinder / piston assembly 10, which is described in more detail below. Figure 3 and Figure 4 And it is a self-filling type, such that the movement of the piston toward the feeding area 6 causes the fluid to be discharged, and the opposite movement of the piston causes the cylinder to be filled with fluid for the next discharge process.

[0048] Figures 2 to 5 The complete cylinder / piston assembly 10 without housing 2 is shown. The cylinder / piston assembly 10 includes a front component 11 and a rear component 12, with the front component 11 connected to the rear component 12. The front component 11 includes a cylinder 13 for containing fluid, the cylinder 13 having an open feeding end 14, a first check valve 15 located in the open feeding end 14, the first check valve 15 being in fluid connection to a nozzle 16. Figure 12 The first check valve 15 can also be clearly seen in the enlarged cross-sectional view of the front component 11, and the first check valve 15 is designed to allow fluid from the cylinder 13 to be supplied via the first check valve 15 and the nozzle 16. It is not possible to draw in air or liquid via the nozzle 16 and the first check valve 15. The check valve 15 is closed in this direction.

[0049] An attachment 7 is also formed at the front component 11, and a second check valve 20 is also formed thereon. Figure 12 Located in attachment 7, a second check valve 20 allows fluid connection between attachment 7 and cylinder 13 and prevents fluid connection in the opposite direction. Attachment 7 has a channel 21 (or supply channel 21) that leads to cylinder 13 via a plurality of radial holes 22.

[0050] The second check valve 20 can be called the inlet valve, and the first check valve 15 can be called the outlet valve.

[0051] Piston 25 has piston end 26 pointing toward the open feeding end 14. Piston 25 is guided in cylinder 13, wherein piston 25 is in Figure 3 , 4 The cross-sectional view of cylinder 12 shows it at its rear end. In this position, cylinder 13 is filled with the fluid to be supplied. Piston 25 is designed here as a rod with a constant cross-section, wherein the portion of the rod that moves back and forth in cylinder 13 is called piston 25, and the portion of the rod that protrudes rearward from cylinder 13 is called piston rod 27.

[0052] The rear end of piston rod 27 (at Figure 4 (Clearly shown in the image) Pointing away from the opening at the feeding end 14, the rear end 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 25 and are guided in the rear component 12. The ends of the guide rods 29 and 30 away from the plate 28 are connected to the actuator 31.

[0053] Furthermore, compression springs 32 and 33 (e.g., coil springs) are arranged for each guide rod 29 and 30. The front ends of the compression springs 32 and 33 are supported on the plate 28, and the rear ends of the compression springs 32 and 33 are supported on the adjacent portion of the rear component 12. Figure 3 and Figure 4 In the position of piston 25 shown, springs 32 and 33 are tensioned.

[0054] Located at the rear end of the rear component 12 is a cover 35, which is based on... Figure 6 The cylinder / piston assembly 10 is not shown in the isometric view so that the actuator 31 can be clearly distinguished. The actuator 31 has a rotatably mounted roller 40, wherein the axis of rotation of the roller 40 extends substantially perpendicular to the longitudinal axis of the rod piston 25.

[0055] Roller 40 operates on ramp path 41 of ramp 42, which rotates below roller 40, wherein ramp path 41 has a single winding, as particularly... Figures 6 to 8 It can be seen in the image.

[0056] exist Figure 8 In the diagram, the rotation angle α is plotted with reference to the pitch difference z in the longitudinal direction parallel to the piston rod 27. It is assumed that at a rotation angle α0 = 0°, there exists a minimum pitch height z0, and the piston 25 is therefore in its front-end position, where the distance from the piston front end to the open feeding end 14 is minimized. This position of the piston 25 is, for example, based on... Figure 11 It is shown in the sectional view.

[0057] The ramp path 41 has a lower plateau 43 adjacent to an inclined region 44 that extends to an upper platform 45. The upper platform 45 is adjacent to a transfer region 46, which incorporates a transition side 47 (rotation angle α1), which in turn leads to the first platform. The rotation angle range from α0 to α2 is therefore equal to 360°.

[0058] The transition side 47 is characterized by its almost vertical extension, as it extends from height z1 to height z0 at a rotation angle (α2 in this case). The transition region 46 is therefore the range of rotation angles from height z1, which continuously decreases from the upper platform 45 until reaching the rotation angle α2 (= transition side 47). Thus, the rotation angle range from α1 to α2 covers the transition region 46.

[0059] The inclined slide 42 is connected to the motor 51 via the coupling 50. Figure 3 ), motor 51 in the first rotation direction 52 ( Figure 6 and 7The ramp 42 rotates. If tensioned from the cylinder / piston assembly 10... Figure 6 Starting at the position shown, motor 51 now further rotates ramp 42 in the first rotational direction 52 (because the user has actuated trigger 5). Due to the tensioned compression springs 32 and 33 accelerating plate 28 in the direction toward open dispensing end 14, roller 40 operates on transfer area 46 and then descends along transition side 47 in the direction toward lower platform 43. Consequently, piston 25, connected to plate 28, also moves toward open dispensing end 14, and fluid contained in cylinder 13 is then discharged via first check valve 15 and nozzle 16 for intramuscular injection into the animal. The dispensing device 1 is designed to allow fluid to safely pass through the skin and be administered to the muscle located beneath the skin. The piston tip is then in its forward position, for example, as shown in the image. Figure 11 As shown in the cross-sectional view, the feeding device 1 is preferably configured such that, in the forward position of the piston front end, the drive 31 is supported on the rear end of the rear component 12, thus the rear end of the rear component 12 forms an abutment of the drive 31. In this position, a desired minimum distance remains between the roller 40 and the ramp path 41, preventing the roller 40 from reaching the lower platform 43 of the ramp path 41. This prevents the roller 40 from impacting the ramp path 41 at the end of the discharge process, which could potentially damage the roller 40.

[0060] After the discharge process, the ramp 42 rotates again in the first rotation direction 52 by means of the motor 51, such that once the roller 40 contacts the ramp path 41 in the inclined region 44, further rotation has the effect that the actuator 31 moves away from the open feeding end 14 along the longitudinal direction of the piston 25, thereby re-tensioning the compression springs 32, 33 and reaching their maximum tension when the roller 40 reaches the upper platform 45. Due to the mechanical connection of the actuator 31 with the guide rods 29 and 30, the plate 28 and the piston rod 27, this movement of the actuator 31 has the effect that the piston 25, and consequently the piston tip, also moves away from the open feeding end in the cylinder 13, thus establishing a negative pressure. Once the established negative pressure is large enough to open the inlet valve, fluid is drawn into the cylinder 13 through the inlet valve and the radial hole 22, so that the cylinder 13 is filled with fluid.

[0061] When the roller 40 (also referred to as a cam or cylinder) reaches the upper platform 45, the motor 51 stops, thereby tensioning the cylinder / piston assembly 10 and thus preparing the device 1 for the next injection process, which can be done by actuating the trigger 5.

[0062] The plate 28, springs 32 and 33, guide rods 29 and 30, driver 31 with roller 40, and ramp together with motor 51 and coupling 50 form a tensioning device S for tensioning cylinder / piston assembly 10.

[0063] In addition, the applicator 1 includes a control unit 54 for controlling the motor 51 and all other electrical components of the applicator 1. Figure 3 A printed circuit board with control unit 54 is shown.

[0064] In the case of application device 1, the important part is cylinder 13 ( Figure 12 and 13 The rear end 60 of the applicator 1 is well sealed because the intended use of the applicator 1 results in high dynamic pressure as well as negative pressure. In the cylinder 13 with pressure space 70, there is positive pressure (during fluid injection) and negative pressure (during aspiration of new fluid for the next injection process). The piston 25 moves much slower during aspiration than during injection. Standard O-ring seals are generally not designed for high dynamic pressure because the O-ring wears out quickly. Furthermore, for example, wear of the O-ring seal can have the disadvantage of clogging the outlet valve. This can lead to malfunction and thus require repair work, and also result in unintended higher maintenance costs.

[0065] According to the present invention, a first sealing element 61 and a second sealing element 62 are therefore provided along a first direction ( Figure 12 (From left to right) is spaced apart from the latter. The first sealing element 61 is designed as a single-function sealing element or a single-acting sealing element that blocks the rear end 60 of the cylinder 13 with respect to positive pressure in the cylinder 13. The first sealing element 61 may be annular and have a U-shaped cross-section (or a V-shaped cross-section), wherein the open end of the U-shaped cross-section (or V-shaped cross-section) opens toward the front end or the opening fitting end 14. Under positive pressure in the pressure space, the two arms of the U-shaped cross-section (or V-shaped cross-section) of the first sealing element 61 are then compressed radially apart from each other, so that the desired sealing effect can be ensured. The first sealing element 61 may have a spring element 61' in the U-shaped cross-section (or V-shaped cross-section), which has compressed the two arms of the U-shaped cross-section (or V-shaped cross-section) radially apart from each other to reinforce the desired sealing effect, such as Figure 14 As shown.

[0066] However, since the single-acting sealing element does not block or only poorly blocks the rear end 60 of the cylinder body 13 with respect to negative pressure in the pressure chamber, a second sealing element 62 is provided. In the exemplary embodiment described herein, the second sealing element 62 is designed as a dual-function sealing element or a double-acting sealing element (e.g., it may be an O-ring seal) that blocks the rear end 60 of the cylinder body 13 with respect to negative pressure in the pressure space 70.

[0067] Since the first sealing element 61 blocks the rear end 60 when there is positive pressure in the pressure space 70, the pressure on the second sealing element 62 is no longer as high as in the case of positive pressure in the pressure chamber compared to previously known solutions, and thus the unwanted wear on the O-ring seal is greatly reduced.

[0068] In addition, a lubrication ring 63 may be provided, which is disposed between the cylinder 13 and the piston 25. The lubrication ring 63 may be, for example, a felt ring or a sponge-like material. For example, the lubrication ring 63 may be coated with oil or grease to ensure optimal possible lubrication of the piston 25.

[0069] exist Figure 12 and 13 In the illustrated embodiment, the first and second sealing rings, along with an optional lubricating ring 63, are arranged in fixed positions on the cylinder 13, allowing the piston 25 to move relative to the first and second sealing rings and the optional lubricating ring 63. Alternatively, the first and / or second sealing rings (preferably both) can be arranged in fixed positions on the piston 25, allowing the piston 25 to move together with the sealing rings. The lubricating ring 63 can also be arranged in a fixed position on the piston 25.

[0070] from Figure 13 As can be clearly seen in the enlarged detail view, the first sealing ring, the second sealing ring, and the optional lubrication ring 63 are arranged in the rear cylinder block component 64. The rear end of the rear cylinder block component 64 also forms the rear end 60 of the cylinder block 13. Furthermore, the rear cylinder block component 64 is connected to the front cylinder block component 66 of the cylinder block 13 via a snap-fit ​​closure 65.

[0071] This makes the cylinder body 13 compact, allowing it to be removed entirely from the device. The compact cylinder body 13 can then be disassembled into multiple parts, and for example, only the rear cylinder body part 64 with the sealing ring and lubrication ring 63 needs to be replaced. Alternatively, during maintenance, only the first and second sealing rings and optionally the lubrication ring 63 can be replaced, and the rear cylinder body part 64 can be reused.

[0072] exist Figure 15 In the illustrated embodiment, the first sealing ring is designed as a grooved ring. In this case, in particular, the obtuse-angled sealing edge can have a larger angle α at the grooved annular surface (compared to the outer face of the sealing edge which has a smaller angle β). Rigid polyurethane can be used as the material.

[0073] Figure 16 It shows Figure 15 Modification of the grooved ring.

[0074] exist Figure 17 middle, Figure 15The grooved ring was modified to be in the form of two parts and additionally have a resilient O-ring that radially presses the sealing edge outward and ensures the desired pretension.

[0075] Figure 18 Another possible embodiment of the first sealing element 61 is shown. In this embodiment, a sealing ring (e.g., PTFE or a PTFE compound) is provided, which has an elastomeric O-ring on its outer surface. The elastomeric O-ring is used to press the sealing ring onto the piston 25. For this purpose, the first sealing element 61 (together with the elastomeric O-ring) is located in a corresponding receiving groove in the rear cylinder block component 64.

Claims

1. A device for applying fluid, comprising: The cylinder body (13) has an open feeding end (14). A piston (25), which is displaceable within the cylinder (13) between a front end position and a rear end position and is connected to a piston rod (27), which protrudes along a first direction from the rear end (60) of the cylinder (13) opposite the open feeding end (14). The first valve (15) closes the opening supply end (14). Supply channel (21), the supply channel being connected to the cylinder (13), and The second valve (20) closes the supply channel (21). in, When the second valve (20) is opened, the fluid to be supplied can enter the cylinder (13) through the supply channel (21), and The movement of the piston (25) toward the open dispensing end (14) in the opposite direction to the first direction generates positive pressure in the cylinder (13), such that when the first valve (15) is opened, the fluid to be supplied from the cylinder (13) is dispensed via the open dispensing end (14). In order to seal the rear end (60) of the cylinder (13), a first sealing element (61) is arranged between the piston (25) and the cylinder (13), and a second sealing element (62) is arranged at a distance from the first sealing element (61) along the first direction. The first sealing element (61) is designed as a single-acting sealing element that seals the rear end (60) of the cylinder (13) relative to positive pressure in the cylinder (13) but not relative to negative pressure in the cylinder (13). The second sealing element (62) is designed as a single-acting or double-acting sealing element that seals the rear end (60) of the cylinder (13) at least relative to the negative pressure in the cylinder (13).

2. The apparatus according to claim 1, wherein, The first sealing element (61) is annular and has a U-shaped or V-shaped annular cross-section, wherein the open end of the U-shaped or V-shaped annular cross-section points to the opening feeding end (14).

3. The apparatus according to claim 2, wherein, The first sealing element (61) has a spring element (61') arranged in the U-shaped or V-shaped annular cross section and the spring element presses the two arms of the U-shaped or V-shaped annular cross section apart from each other.

4. The apparatus according to claim 1, wherein, The first sealing element (61) has an annular sealing member and a spring element (61') that causes the annular sealing member to be subjected to radially inward tension.

5. The apparatus according to claim 4, wherein, The annular sealing component is made of thermoplastic, PTFE, or a mixture of PTFE, and the spring element (61') is made of an elastomer.

6. The apparatus according to claim 1, wherein, The second sealing element (62) is designed as an O-ring seal.

7. The apparatus according to claim 1, wherein, The first sealing element (61) and the second sealing element (62) are arranged in fixed positions on the cylinder (13) such that the piston (25) moves relative to the first sealing element (61) and the second sealing element (62).

8. The apparatus according to claim 1, wherein, The cylinder (13) has a front cylinder portion (66) and a rear cylinder portion (64), the front cylinder portion (66) being releasably connected to the rear cylinder portion (64), the rear end of the rear cylinder portion (64) forming the rear end (60) of the cylinder (13), wherein the first sealing element (61) and the second sealing element (62) are arranged in fixed positions on the rear cylinder portion (64).

9. The apparatus according to claim 8, wherein, The rear cylinder portion (64) is releasably connected to the front cylinder portion (66).

10. The apparatus according to claim 9, wherein, The releasable connection between the rear cylinder portion (64) and the front cylinder portion (66) is provided by means of a snap-fit ​​closure.

11. The apparatus according to claim 1, wherein, A lubrication ring (63) is provided, which is arranged spaced apart from the second sealing element (62) in the first direction.

12. The apparatus according to claim 1, wherein, The first valve (15) is designed as a check valve and / or the second valve (20) is designed as a check valve.

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