DE8625001U1 - Check valve for liquid lines on medical apparatus and devices or similar. - Google Patents

Description

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The invention relates to a check valve as defined in the preamble of claim 1 by

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In the aforementioned check valve, a hat-like structure made of rubber or rubber-like material is arranged inside a valve housing with a hose connection at both ends. A check valve is cut out in the bottom of this hat-like structure, which folds away in the desired flow direction of the liquid and thereby releases the valve opening, but closes when liquid backflow occurs, with the only valve seat surface of the flap-like shut-off body resting against the edge areas of the valve opening*

The well-known check valve, which has an external diameter of about 8 mm, is used in infusion or injection lines for patient care to separate injections and infusions or different infusion agents from one another.

Based on the check valve of this type described at the beginning, the aim of this invention is to create a check valve that is particularly suitable for additional applications. This aim was achieved in accordance with the characteristic part of the.

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It has been shown that the plunger-type shut-off body - in comparison to the state of the art described at the beginning - allows a significant reduction in the outside diameter with the same flow volume/time unit. This is achieved by the flow cross-section on the outside circumference of the plunger-type shut-off body, i.e. in

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surface. While the previously known check valve has an outside diameter of about 8 mm for the same flow volume/time unit, the check valve according to the invention has an outside diameter of only ¹⁴ mm. This considerable reduction in the construction volume makes the check valve according to the invention particularly suitable for integration in multi-way valve blocks.

Because, according to the invention, at least one spacer body is provided adjacent to the outflow side provided axially at one end of the cylindrical interior, which spacer body forms an axially limited displacement of the shut-off body relative to the valve housing and at the same time forms a flow space connecting the flow channels with the outflow side , the invention allows a simple construction and different valve response or valve switching times. The aforementioned features of the invention imply a displacement of the shut-off body relative to the valve housing from a very small value (short valve switching time) to a larger value (longer valve switching time).

In a further embodiment of the invention, the radial cross-section of the cylindrical interior of the valve housing

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and a base body of the shut-off body is circular-cylindrical. In this case, an annular gap is advantageously formed between the wall of the circular-cylindrical interior and the outer surface of the shut-off body by elevations on the valve housing or shut-off body side (which are guides).

While the shut-off body is soft and elastic, the valve housing is made of a much harder plastic. This combination of materials allows the valve seat surface on the shut-off body side to fit particularly tightly against the valve seat surface on the valve housing side in the event of fluid backflow. This is particularly the case when the corresponding seat surfaces are conical with the same cone angle.

A special feature of the invention is the embodiment in which the spacers or spacer feet provided on the downstream side are designed to be spring-loaded and press the valve seat surface of the shut-off body firmly against the valve seat surface on the valve housing side with an overcoming closing pressure. This embodiment means a defined opening pressure that is desired for certain embodiments and can be predetermined by the return spring force of the spacers. The check valve therefore only opens at a certain fluid pressure, but closes particularly quickly when fluid flows back.

Further embodiments according to the invention result from additional subclaims.

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A preferred embodiment according to the invention is shown in more detail in the drawings, which show:

Fig. 1 an exploded view of a check valve with a two-part valve housing and a plunger piston as a shut-off body,

Fig. 2 a front view of the shut-off body according to the arrow marked II in Fig. 1 and

Fig. 3 the check valve according to Figures 1 and 2, assembled in view and partially sectioned.

A check valve (Fig. 3), designated overall with 10, consists of a two-part valve housing 11 with a cylinder part 12 and a cover part 13.

Cylinder and cover parts 12, 13 each form a hose connection piece 14 or 15 with axially open supply lines 16, 17 at both ends. The inflow side is at 16 and the outflow side at 17.

It is conceivable that infusion tubes not shown are pushed onto the tube connection sockets 14, 15 with a press fit.

Cylinder part 12 and cover part 13 form rotationally symmetrical plastic injection molded parts made of relatively hard plastic with a Shore A hardness of approx. 90-95.

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A cylindrical interior space 18 with a circular-cylindrical cross-section is provided within the cylinder part 12. The circular-cylindrical interior space 18 is connected to the drain line 17 in a fluid-conducting manner via an opening la with a circular cross-section.

The cover part 13 has, on its side adjacent to the cylinder part 12, a contact flange 20 and a collar 21 offset from it, to which an outer cone 22 with an annular outer cone surface 23 (VentiJ counter seat surface) is connected at the end. The outer diameter D of the contact flange 20 is equal to the outer diameter

diameter D of the cylinder part 12. The inner diameter D of the collar 21 corresponds approximately to the inner diameter O^ of the circular cylindrical interior 18. In this way, the collar 21 can be inserted tightly into the inflow side of the circular cylindrical interior 18, whereby the flush-aligned contact flange 20 with its radial annular surface 24 lies snugly against the radial annular surface 25 of the cylinder part 12. The joint can be secured by suitable measures, e.g. by gluing.

Within the circular cylindrical interior 18, a shut-off body 26 designed in the manner of a plunger piston with a radial sliding seat is accommodated so as to be axially displaceable back and forth in the direction &khgr;.

The shut-off body 26 is also a plastic injection-molded part, which, however, is made of a relatively soft plastic with a Shore A hardness of 50-55.

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To guide it on the inner wall 27 of the circular-cylindrical interior 18, the shut-off body 26 has axial ribs of equal cross-sectional thickness and part-circular cross-section that are evenly distributed over the outer surface 28 of its base body 29. These axial guide ribs can be clearly seen in Fig. and are designated there with the reference number 30.

The guide ribs 30 form an annular gap 33 consisting of several axial chambers or flow channels 36 between the inner surface 27 of the circular-cylindrical interior 18 and the likewise circular-cylindrical outer surface 28 of the base body 29 of the shut-off body 26, which can be seen in Fig.

In the embodiment shown, the base body 29 of the shut-off body 26 is designed with a full cross-section over its entire axial length. Adjacent to the inflow side, i.e. adjacent to the valve counter seat surface 23, the base body 29 forms a corresponding valve seat surface 31 in the form of a circular ring-shaped inner cone. It should also be mentioned in this context that a circular cylindrical through-opening 32 is provided adjacent to the supply line 16 and is connected to it, which passes centrally through the collar 20, the contact flange 21 and the outer cone 22.

Fig. 3 shows that the valve seat surface 31 fits tightly against the valve counter seat surface 23. This is ensured by spacer feet 30 as one-sided extensions of the axial ribs

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34, which can be compressed due to the elastic properties of the plastic used and due to their shape (slimness or free bending) as soon as a predetermined fluid pressure is present in the supply line Iu, 32,

The spacer feet 34 simultaneously create a flow space 37 which, when the valve 10 is in the open position, connects the downstream side 19, 17 with the flow channels 36.

As soon as the shut-off body 26 (i.e. its spring-loaded spacer feet 34) which is pre-tensioned in the closed position in a certain sense in the embodiment shown in Fig. 3 has given way to the fluid pressure on the inflow side (at 16), a fluid flow occurs in the inflow direction a. As soon as the fluid pressure on the inflow side (at 16) falls below a minimum level, the spring-elastic restoring force of the spacer feet 34 (possibly in conjunction with a backflow of the fluid in the direction r) ensures that the shut-off body 26 closes within a very short time.

In the embodiment shown in Fig. 3, the total axial length L of the shut-off body 26 is gl< or slightly larger than the length measured at the same point.
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the total axial length L of the shut-off body 26 is equal

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If the valve switching time is to be increased when the flow is reversed (the liquid flows in direction r), the axial length L of the shut-off body 26 can be reduced,

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for example by partially shortening the spacer feet 34,

In practice, it has been shown that a rapid closing process in the reverse flow direction is further promoted by the fact that a particularly conical recess is provided on the front side of the base body 29 facing the outflow side (at 17).

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Overall, it remains to be mentioned that the drawings are on a greatly enlarged scale. This is clear from the fact that the external diameter D is only 4 mm.

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Claims (12)

Patent attorneys / Dipi.-Ing. HaraRdOstrigä-i · :öjpT.-ing. Bernd Sonnet Wuppertal-B armen Stresemannstraße 6-8 Authorized by the European Patent Office Patemanwalle Ostriga & Sonnet, PO Box 2013 27. D-5600 Wuppertal 2 0/g Applicant: Mr. Rolf Holthaus Harlinger Str. 12 5880 Luedenscheid Designation of the invention: Check valve for liquid cables on medical devices and devices or the like. Expectations 1. Non-return valve for lines on medical apparatus and devices or the like, with a valve housing made of plastic and a soft-elastic shut-off body, the only valve seat surface of which rests against a single valve counter-seat surface on the valve housing side in the event of fluid backflow, characterized in that the valve counter-seat surface (23) is provided axially at one end of a cylindrical interior (18) of the valve housing (11), that the valve seat surface (31) is formed by a plunger piston (26) as a shut-off body, which is connected on the outer circumference by guides (30) on the inner surface (27) of the cylindrical interior (18) with Pösischeckkufitö Oedli-.y, Vqlksbaiik cÖmbll, Cümmcribank AG, <TT» (0202) Essin · · ».Wupferlal'Harmcm * · · Wuppertal-BarmCn, £fc 557040 (BLZ36010043)44504-431 « &eacgr; i\hkZ 310*60(338) 158»&iacgr;&iacgr; (IiU33040001)4034823 Rolf Holthaus _f · _fe . 1 ll · J 1 5·&bgr; 1)1 · 1.111 » ·« · · ·■ II ■ «fl« B 111 ■ · · * 11111 she ■ 11111 11 : 1 ti 1 1 1 1 '■ radial sliding seat is guided a-axially (at &khgr;), that flow channels (35) are formed essentially on the outer circumference of the shut-off body (26) and that adjacent to the axially other end of the cylindrical interior (IS) provided outflow side (at 17) at least one spacer body (34) is provided, which forms an axially limited displaceability of the shut-off body (26) relative to the valve housing (11) and at the same time a flow space (37) connecting the flow channels (36) with the outflow side (at 17). 2. Check valve according to claim 1, characterized in that the radial cross section of the cylindrical interior (18) of the valve housing (11) and of a base body (29) of the shut-off body (26) are circular-cylindrical. 3. Check valve according to claim 1 or claim 2, characterized in that between the wall (27) of the cylindrical interior (18) and the outer surface (28) of the shut-off body (26) an annular gap (33) is formed by elevations (30) on the valve housing or shut-off body side as guides. 4. Check valve according to one of claims 1 to 3, characterized in that the guides are formed by axial ribs (30) evenly distributed over the outer surface (28) of the shut-off body (26). 5. Check valve according to one of claims 1 to 4, characterized in that the valve seat surface (31) and the valve counter seat surface (23) are conical with the same cone angle. Il MH Il * Rolf Hoithaus I t t t I I 6. Check valve according to one of claims 1 to 5, characterized in that the valve counter-face (23) on the valve housing side forms a rotationally symmetrical annular inner cone surface and the valve seat surface (31) of the shut-off body (26) made of soft elastic plastic forms an annular outer cone surface. 7. Check valve according to one of claims 1 to 6, characterized in that the base body (29) of the shut-off body (26) is designed to have a full cross-section at least over a part of its axial extent. 8. Check valve according to one of claims 1 to 7, characterized in that at least two or three axially directed feet (34) of the same axial length, particularly evenly distributed over the circumference of the shut-off body, are formed as spacers on the shut-off body (26) adjacent to the valve housing-side downstream side (at 17). 9. Check valve according to one of claims 1 to 8, characterized in that the spacer feet (34) can be bent or compressed when pressure is applied on the inflow side (in direction a). /j If t I 10. Check valve according to one of claims 1 to 9, characterized in that the spring-loaded or bendable spacer feet (34) hold the valve seat surface (31) of the shut-off body (26) tightly against the valve housing-side valve counter seat surface (23) with an surmountable closing pressure. Rolf Holthaüs ti · · * ■ ti lit &igr; t*· tttitt ti &igr; ti · · &igr; ic«' M * i ti Il « f -A- 11. Check valve according to one of claims 1 to 10, characterized in that when the valve (10) is closed, including the spacer body or feet (34), the total axial length (L ) of the shut-off body (26) is less el as the total axial length (L^) of the cylindrical interior (18) (cf. Fig. 3). 12. Check valve according to one of claims 1 to 8, characterized in that the front side of the shut-off body (26) has a particularly conical recess (35) adjacent to the outflow side (at 17).