Device for dispensing liquid media
Patent Information
- Application Number
- JP2024556404
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-03-22
- Filing Date
- 2023-03-22
- Publication Date
- 2026-02-10
AI Technical Summary
Conventional dosing devices often require multiple activations to remove air and achieve accurate liquid dispensing, leading to dosage loss and inefficiency, which is critical in medical applications.
A device with a first and second housing portion, a piston, a plunger, and inner and outer seals that allow for efficient liquid filling and separation, enabling immediate release of the administered dose without air entrapment.
The device ensures immediate and accurate dispensing of liquid media, minimizing dosage loss and maintaining product integrity, particularly beneficial in medical applications where precision and efficiency are paramount.
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Abstract
Description
[Technical field]
[0001] The present invention relates to a device for the portioning and dispensing of a liquid, preferably a therapeutic medium, according to the preamble of claim 1. [Background technology]
[0002] The dosing device for fluids has a dosing housing, such as that known from EP 3072597 A1, which projects into the fluid container, in which a piston is guided in a sealed manner. A pressure chamber is formed in the dosing housing. A valve acting in the opposite direction to the fluid container is designed to close at overpressure and open at underpressure. The geometry of the pressure chamber defines the dispensing volume per stroke. The piston is provided with an axial piston bore and is held in a rest position by a return spring. When the piston is actuated and moves axially, the fluid in the pressure chamber is first compressed, creating an overpressure, which closes the valve. As soon as the valve closes, the piston continues to move axially and the fluid is conveyed through the piston bore when the valve closes. Summary of the Invention [Problem to be solved by the invention]
[0003] Conventional dispensing devices often must first be actuated several times to initially evacuate the dispensing housing by pumping several times before liquid is drawn from the contained supply. Thus, a precisely divided dispensed volume is only achieved after repeated actuations. Furthermore, some systems are prone to loss of volume after extended periods of non-use, as the liquid in the dispensing housing leaks back into the reservoir by gravity.
[0004] Losses of dose, when combined with repeated strokes of the dosing device, are not an issue in some technical applications. In medical products and pharmaceuticals, however, they become a determining factor or disadvantage. For example, in pharmaceutical development of nasal spray pumps, rapid response in addition to dosing accuracy per stroke must be tested and suitable support must also be available on the product.
[0005] A generic type of splitting and dispensing device is known from DE 102009017459 A1. Other dispensing devices are known from DE 10151781 A1, EP 1 194246 A1 or EP 2 939 750 A1. WO 2016 / 174031 A1 discloses a flexible dispensing housing which contracts when fluid is actuated and dispensed.
[0006] The invention is based on the problem of achieving a device that responds without delay when activated, releases the administered dose immediately, is manufacturable at low cost and has a small number of parts. [Means for solving the problem]
[0007] To achieve this objective, a device for dispensing a liquid medium is proposed having the features of claim 1. a first housing part and a second housing part arranged to be longitudinally movable relative to one another on a common longitudinal axis between an unactuated rest position and an actuated end position; a piston disposed in an axially fixed relationship with respect to the first housing portion; a plunger disposed in axially fixed relation to a second housing portion, the second housing portion being disposed in longitudinal alignment with the piston and having a closed end face and a plunger casing; a dosing cavity bounded by an inner wall of the piston and capable of being lowered by actuation of the plunger of the device; a fluid channel extending from the dosing cavity and in fluid communication with a valve-controlled outlet of the first housing portion; It is equipped with:
[0008] The device of the present invention is characterized by an inner seal formed on the inner wall of the plunger and an outer seal formed on the outside of the plunger casing which fits snugly against the plunger when the plunger is partially or completely lowered into the dosage cavity.
[0009] The operation of the device can be divided into individual stages. The first stage is the idle or initial state, where the device is not yet activated. In this state, there is no contact between the piston and the plunger, and therefore no mutual sealing. The therapeutic liquid can therefore flow unhindered into and fill the dosing cavity.
[0010] However, in the second and third stages, i.e. when the plunger is partially lowered into the dosing cavity and when the plunger is fully lowered, the inner seal tightly seats against the opposing outer seal, so that from the second stage onwards the dosing cavity is isolated from the liquid supply of the surrounding storage space. In the third stage, pressure is applied to the separated medium, forcing it outwards towards the outlet.
[0011] Advantageously, but not necessarily, the designs of the device according to the invention are given in separate subclaims.
[0012] In a first design, it is provided that a liquid channel is arranged in the piston, which starts at the bottom of the dosing cavity but extends initially along the piston.
[0013] The storage space for accommodating the medium is preferably part of the second housing part. The valve-controlled outlet is preferably arranged in the first housing part.
[0014] It is beneficial for the functioning of the dosing cavity if the arrangement of the inner seal and the outer seal is located in and surrounded by the storage space.
[0015] It is beneficial for the function of the dosing cavity if the plunger is arranged on the plunger carrier facing away from the end face, where the plunger carrier is arranged in the storage space and is provided with a number of openings through which the medium flows. The openings may be distributed around the circumference of the plunger carrier. In this case, the plunger carrier forms the movement space of the axially movable piston arranged therein.
[0016] The inner wall of the dosing cavity may be designed as a cylindrical longitudinal section over most of its length, adjoined by a longitudinal section that conically tapers towards the plunger.
[0017] A valve is also proposed, which is arranged at the transition between the dosing cavity and the liquid channel. The valve is designed to open only towards the liquid channel. In the displacement phase, the valve allows compression in the dosing cavity. Only when the expulsion phase is reached does the valve open and free the liquid channel for the medium to flow, whereby the valve prevents leakage, backflow or contamination of the medium contained in the storage space once expulsion is completed. [Brief description of the drawings]
[0018] Exemplary embodiments of the device are described in further detail below with reference to the drawings. [Figure 1] FIG. 1 shows a first embodiment of a device for dispensing a liquid medium, namely still in the inoperative or initial position. [Diagram 2] FIG. 2 shows the same device at an intermediate stage of operation, where the dosing cavity has initially been separated from the storage space. [Diagram 3] FIG. 3 shows the same device in the end position of operation, ie at the end of the dispensing phase. [Figure 4] FIG. 4 shows a second embodiment of a device for dispensing a liquid medium, namely in the intermediate stage shown in FIG. 2 for the first embodiment. [Diagram 5] FIG. 5 shows a third embodiment of a device for dispensing a liquid medium, again in the intermediate stage shown in FIG. 2 with respect to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] The device shown in figures 1 to 3 in a first embodiment is used for the fractional dispensing (metered dispensing) of liquid media, in particular therapeutic liquids such as nose drops or eye drops. The device may also be used for dispensing other media and media for other purposes in portions, i.e. in defined, reproducible volume units. The device has a first housing part 1 and a second housing part 2, which are arranged for longitudinal displacement relative to one another along a common longitudinal axis A between a non-activated rest position (figure 1) and an activated end (end) position (figure 3). Activation by the user is usually performed by pressing the thumb against the end of the second housing part 2 and simultaneously placing two fingers on the first housing part 1 to absorb the counter pressure.
[0020] The housing parts 1, 2 can be designed rotationally symmetrically, which facilitates handling. The housing parts 1, 2 are equipped with fixing structures 4a, 4b which are actuated on one side. The fixing structures 4a, 4b allow the two housing parts 1, 2 to be pressed against one another while dispensing, i.e. releasing a dose of liquid, but do not allow the two housing parts 1, 2 to be released from one another. A spring 7 between the housing parts 1, 2 ensures that when not actuated, the fixing structures 4a, 4b are pressed back into the initial or rest position, i.e. until they come into contact with one another.
[0021] Part of the second housing part 2 is a storage space 5 in which the liquid medium to be dispensed is accommodated. The amount is sufficient to perform a large volume ejection. Depending on the design of the housing parts 1, 2, the storage space 5 may also include part of the space located in the first housing part 1.
[0022] The piston 10 is part of the first housing part 1 and is therefore axially fixed therein. The piston 10 has the shape of a punch and extends along a longitudinal axis A. The piston 10 is provided with a central liquid channel 11 which leads to a valve unit 12 arranged in the first housing part 1. In the figure, the channel cross section of the liquid channel 11 is exaggerated for representation reasons.
[0023] Part of the valve unit 12 is a valve body 15 which is biased in the closing direction by a closing spring 14 and operates in a pressure-dependent manner. In the closed position shown in Figure 1, the valve body 15 closes an outlet 16 located at the end of the first housing part 1.
[0024] The valve body 15 is designed to open against the spring pressure of the closing spring 14 only if the pressure of the liquid medium is high enough, thereby opening the outlet 16. In this way, the liquid flows out of the liquid channel 11, preferably partially around the valve unit 12, to the outlet 16 and from there it ejects.
[0025] At its other end, the liquid channel 11 terminates in a dosing cavity 17. The dosing cavity 17 is a pan-shaped, essentially cylindrical space on the end and longitudinal axis A of the piston 10. The dosing cavity 17 is circumferentially surrounded by an inner wall 19 of the piston 10. The inner wall 19 is completely closed. At its one axial end, the dosing cavity 17 has a base 18 (FIG. 2) from which the liquid channel 11 extends. At its other end, the dosing cavity 17 is open.
[0026] The plunger 20 is part of the second housing part 2 and is therefore axially fixed thereto. The plunger 20 extends along the longitudinal axis A and is therefore longitudinally aligned with the piston 10. The plunger 20 has the shape of a punch and has an end face 21 facing the dosing cavity 17 and a plunger casing 22. The end face 21 is designed as a closed pressure face. In the embodiment shown, the plunger casing 22 is also closed, but may also be provided with an opening.
[0027] The plunger 20 of the second housing part 2, in cooperation with the piston 10 of the first housing part 1, is intended to descend during actuation of the device into the dosing cavity 17 and, as it descends, to apply the pressure necessary to first divide a quantity of liquid in the dosing cavity and then to expel the quantity of liquid. The relative movement performed here is along the longitudinal axis A.
[0028] For both of these effects, a graduated seal is required between the dosing cavity 17 and the plunger 20. For this purpose, the inner wall 19 of the piston 10 surrounding the dosing cavity 17 forms an inner seal 31. When the plunger 20 is at least partially lowered into the dosing cavity 17 (FIG. 2) and when the plunger 20 is completely lowered into the dosing cavity 17 (FIG. 3), an opposing seal 32 located on the outside of the plunger casing 22 rests (abuts) against the inner seal 31 without a gap. In the present embodiment, this outer seal 32 is a sealing bead that extends in the shape of a ring around the plunger casing 22 at the level of the end face 22.
[0029] Figure 2 shows the initial contact between the piston 10 and the plunger 20, which contact takes place at the seals 31, 32. From this point 35 onwards, the division in the dosing cavity 17 is complete. No more liquid can enter the dosing cavity. From this point onwards, a pressure phase starts with the expulsion of the dispensed amount of liquid. Its completed form is shown in Figure 3.
[0030] In contrast, Fig. 1 illustrates an unactuated rest or initial state, in which there is not yet a seal between the inner wall 19 of the piston 10 and the plunger 20. In this state, the piston 10 is arranged at an axial distance from the plunger 20, so that the seals 31, 32 are also not yet in contact and therefore the therapeutic liquid can enter the dosing cavity 17 unhindered. In particular, the arrangement of the inner seal 31 and the outer seal 32, which are therefore located in and surrounded by the storage space 5, provides for a reliable inflow of liquid from the storage space to the dosing cavity 17.
[0031] Also contributing to this inflow is the fact that the plunger 20 is arranged in a plunger carrier 36, located in the storage space 5 and equipped with a number of openings 37 through which the medium can flow. The openings 37 are arranged in a distributed, preferably evenly distributed, manner over the circumference of the plunger carrier 36. The interior of the plunger carrier 36 forms the movement space of the piston 10, which moves axially therein.
[0032] At the intermediate stage shown in Figure 2, where the seals 31, 32 come into contact for the first time, in order to keep the mechanical stresses in the edge areas low, the inner wall 19 of the dosing cavity 17 is designed as a cylindrical longitudinal section over most of its length, adjacent to a shorter, conically tapering longitudinal section towards the plunger 20.
[0033] FIG. 1 also shows a valve 40, which is arranged between the dosing cavity 17 and the liquid channel 11, in the exemplary embodiment located at the base 18 of the cavity 17. The valve 40 is not explicitly shown in the other figures of the drawing. The valve 40 allows compression in the dosing cavity 17 during the displacement phase. The valve 40 opens only when the expulsion phase is reached and then releases the liquid channel 11 for the dispensed liquid quantity to flow through. After completion of the liquid expulsion, the valve 40 prevents backflow or contamination of the residual volume in the piston bore. The dosing device can thus structurally and functionally protect the filling material in the container from contamination.
[0034] Figure 4 shows a second embodiment of the device. As shown in figure 2 for the first embodiment, only intermediate stages are shown. When dealing with the second embodiment, the arrangement of the housing parts is reversed from that shown in figures 1 to 3. The first housing part 1 with the piston 10 and the outlet 16 is located at the top, and the second housing part 2 with the plunger 20 is located at the bottom. Due to the upward facing outlet 16, this embodiment is suitable for example for administering nasal drops, whereas the first embodiment is more suitable for administering eye drops in the medical field.
[0035] Figure 5 shows a third embodiment. Again, as shown in Figure 2 for the first embodiment and in Figure 4 for the second embodiment, only intermediate stages are shown.
[0036] When dealing with the third embodiment, the arrangement of the housing parts 1, 2 is of little importance. By way of example, an arrangement with a horizontal longitudinal axis A is shown here, so that the outlet 16 is also horizontal with respect to the corresponding application.
[0037] In FIG. 5, the storage space 5 for the liquid medium to be dispensed is again surrounded by the solid housing material of the second housing part 2 and further by an inner lining 45 in the form of a bag. The lining 45 is made of a flexible material that is impermeable to liquids. The lining 45 initially lies (abuts) against the inner wall of the housing part 2 but is not connected and is designed and sealed in such a way that the contained liquid is trapped in a completely airtight manner. If the volume of the liquid gradually decreases as a result of repeated releases, the size of the lining 45 will decrease accordingly as the bag shrinks. However, the (remaining) storage space 5 thus surrounded remains completely filled with liquid medium at all times, so does the area around the dosing cavity 17 at all times. [Explanation of symbols]
[0038] 1 First housing part 2 Second housing part 4a fixed structure 4b Fixed structure 5. Storage Space 7. Spring 10 Piston 11 Liquid Channel 12 Valve unit 14 Closing spring 15 Valve body 16 Outlet 17 Dosing cavity 18 base 19 Inner wall 20 Plunger 21 End face 22 Plunger casing 31 Inner seal 32 Outer seal part 36 Plunger carrier 40 Valve 45 Lining A Longitudinal axis
Claims
1. A device for dispensing a liquid, preferably a therapeutic medium, comprising: a first housing part (1) and a second housing part (2) arranged to be longitudinally movable relative to one another along a common longitudinal axis (A) between an inactive rest position and an activated end position; a piston (10) arranged axially fixed in the first housing part (1); a plunger (20) arranged axially fixed to the second housing part (2), aligned longitudinally with the piston (10), and comprising a closed end face (21) and a plunger casing (22); a dosing cavity (17) surrounded by the inner wall (19) of the piston (10) and in which the plunger (20) can be lowered by actuation of the device; a liquid channel (11) extending from said dosing cavity (17) and in fluid communication with a valve-controlled outlet (16) of said first housing part (1); Equipped with A device in which an inner seal (31) formed on the inner wall (19) of the piston (10) fits snugly against an outer seal (32) formed on the outside of the plunger casing (22) when the plunger (20) is partially or completely lowered into the dosing cavity (17).
2. the liquid channel (11) starts at the base (18) of the dosing cavity (17) and extends initially along the piston (10); The device of claim 1 .
3. The valve-controlled outlet (16) is located in the first housing part (1).
3. A device according to claim 1 or 2.
4. A part of the second housing part (2) is a storage space (5) for storing a medium.
3. A device according to claim 1 or 2.
5. The arrangement of the inner seal portion (31) and the outer seal portion (32) is located in the storage space (5) and is surrounded by the storage space (5); The device of claim 4.
6. The plunger (20) is disposed on a plunger carrier (36) facing away from the end face (21); The plunger carrier (36) is located in the storage space (5) and has a plurality of openings through which a medium can flow. The device of claim 4.
7. The openings are distributed, preferably evenly distributed, around the circumference of the plunger carrier (36). The device of claim 6.
8. The interior of the plunger carrier (36) is designed as a movement space for the piston (10) arranged axially movably therein. The device of claim 6.
9. the inner wall (19) of the dosing cavity (17) is designed as a cylindrical longitudinal section over most of its length, adjacent to a longitudinal section that tapers conically towards the plunger (20); 3. A device according to claim 1 or 2.
10. a valve (40) is arranged at the transition between the dosing cavity (17) and the liquid channel (11); 3. A device according to claim 1 or 2.
11. A part of the second housing part (2) is a storage space (5) for accommodating a medium, the valve (40) allows compression in the dosing cavity (17) in the displacement phase and opens only when the expulsion phase is reached to release the liquid channel (11) for the medium to flow through, and the valve (40) prevents leakage, backflow or contamination of the medium contained in the storage space after expulsion is completed. The device of claim 10.