CA2606540C

CA2606540C - Check valve, especially for medical use

Info

Publication number: CA2606540C
Application number: CA2606540A
Authority: CA
Inventors: Jan Willem Marinus Mijers; Brendan Hogan
Original assignee: Filtertek BV
Current assignee: Illinois Tool Works Inc
Priority date: 2004-06-17
Filing date: 2005-06-15
Publication date: 2010-11-09
Anticipated expiration: 2025-06-15
Also published as: WO2005123176A1; EP1755730B1; DE502005009277D1; EP1755730A1; CA2606540A1; DE202004009521U1

Abstract

The invention relates to a non-return valve, particularly for medial applications, comprising a first tube connection housing (2), a second tube connection housing (4) and a diaphragm disk (6), which is made of flexible material, is placed between both tube connection housings, and which, in the existence of an excess pressure inside an entry passage in the first tube connection housing, can be lifted off from a valve seat (12) annularly surrounding an inlet space connected to the entry passage (8). In the existence of an excess pressure inside an outlet passage (24), the diaphragm disk can be securely pressed against the valve seat in the shortest of times, and is provided with an annular bead (14) on its outer peripheral area. This annular bead is accommodated inside opposing annular grooves of the hose connection housing. The diaphragm disk is provided with openings (20) radially outside the valve seat that are connected to an outlet space. A formation (28), which lies on the side of the diaphragm disk (6) facing the outlet space (22) and which holds or prestresses the diaphragm disk (6) in the direction of the inlet space (10), is provided on the wall (26) of the second tube connection housing (4) located opposite the diaphragm disk (6). Said formation (28) is placed inside the boundary given by the valve seat (12).

Description

Check Valve, especially for Medical Use.

The invention relates to a check valve, especially for medical use, having a first hose connector housing and a second hose connector housing and a membrane disk of flexible material po-sitioned between the two hose connector housings which with an overpressure in an entry passage in the first hose connector housing can be lifted from an annular valve seat surrounding an entry space connected with the entry passage and which with an overpressure in an exit passage safely and in minimal time can be pressed onto the valve seat, wherein the membrane disk at the outer circumference thereof is provided with an annular protrusion which is received within annular grooves oppositely provided in the hose connector housings, wherein the membrane disk radially exterior of the valve seat is provided with openings which are connected to an exit space.

Such a check valve is known from the European patent 0 612 537 according to a prior proposal of the applicant.

In the medical technique, such check valves are used for the lines of infusion systems, syringes, diagnosis equipment, in-travenous hose lines and in connection with syringe pumps.
Such check valves have to have closing times of few fractions of seconds and have to close safely to avoid any reflux of possibly contaminated fluids. Since such check valves in the medical technique merely are used as a one-way article simul-taneously the production, on the one hand, has to be extremely economical and, on the other hand, statistically very accu-rate. Additionally, there are stringent legal provisions and tests to ensure a continuous and uniform safety in function.
In Germany, this for example is tested in detail by the TUV
before after achieving positive results, a release for the medical application is achieved. These demands have been met in connection with the above-mentioned check valves according to a prior proposal of the applicant since in this known con-struction the annular grooves receiving the annular protrusion at the circumferential area of the membrane are designed such that during the assembly the two hose connector housings are creating radially directed tension forces in the membrane disk such that thereby an adjustment of the tension forces in the membrane can be achieved ensuring an extremely fast and safe action of the check valve.

The practical use of this known check valve however has shown that it is desirable to enable the provision of valves having higher opening pressures in a simple manner. For example in connection with the use of syringe pumps it has to be ensured that said pump not simply can run empty due to the difference in height between the patient and syringe pump since the valve could already open because of the geodetic height. Since such valves however usually are assembled from injection moulded parts, the production of valves having different opening pres-sures lead to substantial costs of the moulds.
Followingly, it is the task to be solved by the present inven-tion to improve valves of the above-identified kind in such a way that by simple means different opening pressures can be provided.
In a valve of the above-identified kind this task basically is solved according to the invention by the features that on the wall of the second hose connector housing opposite to the men-brane disk there is provided a formation engaging the side of

2 the membrane disk facing the exit space which is holding or pretensioning, respectively, the membrane disk in the direc-tion of the entry space and that the formation is positioned within the limits defined by the valve seat.
It is obvious that by the support of the membrane disk within the valve seat provided by the formation or by the magnitude of the opposite pretension created by the formation within the membrane disk a simple possibility is provided to manufacture valves of different opening pressures by either modifying the radius within which such a formation is positioned within the limits of the valve seat or modifying the height of the forma-tion and followingly the magnitude of the opposite pretension.
This with low mould costs can simply be achieved by merely modifying one half of the mould used for the production of the second hose connector housing.

In a preferred embodiment according to the invention, the for-mation is made pervious to media, i.e. that the formation is scarcely impeding the flow through the opened valve.

An especially preferred embodiment according to the invention can be created by the features that the formation is formed by a number of projections which are surrounding the entry open-ing of the exit passage from the exit space in the shape of a crown.

Further, it is preferred that the formations are monolithic with the second hose connector housing.
In the following, the invention is more detailly described with reference to an exemplary embodiment shown in the draw-ing. The drawing shows a cross-sectional view of the check

3 valve according to the invention in one possible embodiment and in the final assembled state.

The check valve 1 shown in the drawing is especially suitable for medical use and is for example suitable for opening pres-sures between 0,14 and 0,42 bar while check valves of the above-identified kind according to a prior proposal of the ap-plicant are designed for pressure differences between 0,1 to 0,002 bar.
The check valve 1 is consisting of a first hose connector housing 2 and a second hose connector housing 4 which for ex-ample are produced by injection moulding from plastics and a membrane disk 6 clamped between these housings. The membrane disk 6 is consisting of a flexible material, e.g. silicon.

The first hose connector housing 2 is having a first entry passage 8 leading to an entry space 10. The entry space 10 is surrounded by an annular valve seat 12 against which the mem-brane disk 6 is pretensioned.

The membrane 6 in the area within the valve seat 12 is unitary such that substantial tension forces can be transmitted ra-dially from the interior to the exterior and vice versa. At the outer circumferential area the membrane 6 is provided with an annular protrusion 14 which for example is injection moulded to the membrane disk 6 in case the membrane disk, too, is made by injection moulding of the silicon. In the first hose connector housing 2 in the front face thereof there is provided an annular groove 16, wherein an annular groove 18 of the second hose connector housing in the assembled state is oppositely positioned. During the assembly of the first hose connector housing with the second hose connector housing the annular protrusion 14 is received within the two oppositely

4 positioned annular grooves 16 and 18 of the two hose connector housings 2 and 4 and simultaneously the membrane disk 6 is pretensioned against the valve seat 12.

As further can be learnt from the drawing, the membrane disk 6 radially exterior of the valve seat 12 is provided with open-ings 20 positioned on a radius which are connecting an annular space 21 in the first hose connector housing 2 radially exte-rior of the valve seat 12 with an exit space 22 of the second hose connector housing 4, the latter being connected with an exit passage 24 of the second hose connector housing 4.

The wall 26 of the second hose connector housing 4 is posi-tioned opposite to the membrane disk 6 and is limiting the exit space 22 in the upward direction. On the wall 26 there are provided projecting formations generally designated with 28 which are pervious to media. The formations 28 are support-ing the membrane disk 6 or are pretensioning the membrane disk 6 in the direction of the entry space 10, respectively. As shown, the formations 28 are positioned within the limits de-fined by the valve seat 12.

In the exemplary embodiment shown, the formation 28 is formed by a number of projections 30. The projections 30 in the shape of a crown are surrounding the entry opening 32 of the exit passage starting from the exit space. As shown, the projec-tions 30 by injection moulding are formed monolithically with the second hose connector housing 4. It is obvious that by the height of the projections 30 the oppositely directed preten-sion exerted on the membrane disk 6 can be modified which ob-viously is leading to a modification of the opening pressure of the check valve 1. As an alternative it is possible, too, to modify the distance between the valve seat 12 and the pro-jections 30 in a radial direction, wherein thereby the lever

5

6 PCT/EP2005/006425 between these parts is changed in its size. Hereby, too, a modification of the opening pressure of the check valve 1 is possible.

For the assembly the two hose connector housings 2 and 4 by means of an inner annular projection 34 on the first hose con-nector housing 2 and by means of an exterior annular projec-tion 36 on the second hose connector housing 4 which are in-terengaging can be connected. After providing this connection, the final assembly for example can be done by ultrasonic weld-ing.

All features and advantages of the invention which can be learnt from the specification, the claims and the drawing in-cluding constructive details and positions in space can be substantial for the invention individually as well as in cb-liberate combination.

REFERENCE NUMERALS
1 = check valve 2 = first hose connector housing 4 = second hose connector housing 6 = membrane disk 8 = first entry passage 10 = entry space 12 = annular valve seat 14 = annular protrusion 16 = annular groove 18 = annular groove 20 = openings 22 = exit space 24 = exit passage 26 = wall 28 = formation 30 = projections 32 = entry opening 34 = inner annular projection 36 = exterior annular projection '7

Claims

What is claimed is:

1. A check valve for liquid applications comprising:
a first hose connector housing defining an entry passage extending into an entry space at least partially defined by an annular valve seat;
a second hose connector housing coupled with the first hose connector housing, the second hose connector housing defining an exit passage, an outer rim, a plurality of supporting surfaces spaced circumferentially about the exit passage the supporting surfaces defining recesses therebetween, and at least one groove fluidly connecting at least one recess with the exit passage, the second hose connector housing defining a series of discontinuous protrusions spaced circumferentially about the exit passage and extending generally toward the entry passage; and a generally flexible membrane disk clamped between the first and second hose connector housings such that the membrane disk engages the protrusions and selectively engages the valve seat, the membrane disk defining at least one opening located radially outwardly from the valve seat, where the membrane disk is configured to be movable between a seated position, where the entry space and the exit passage are fluidly sealed from each other by the membrane disk, and an unseated position, where the entry space and the exit passage are fluidly connected via the at least one opening;
wherein the valve seat is located radially outwardly from the protrusions such that the protrusions about the exit passage circumferentially support the membrane disk toward the entry space and pretensions the membrane disk against the valve seat such that an unseating pressure required to move the membrane disk from the seated position to the unseated position is at least partially determined by the radial distances between the valve seat and the protrusions, and wherein the supporting surfaces each define a first radial portion extending substantially along the radial distance between the exit passage and the outer rim and a second radial portion connected to the first radial portion adjacent the exit passage and extending across a portion of the radial distance between the exit passage and the outer rim, thereby defining a second recess between the first radial portion and second radial portion fluidly connected to the recess between supporting surfaces, wherein the membrane disk opening overlies a recess between the first and second radial portions such that the membrane disk at the unseated position under high differential pressures engages the first and second radial portions.

2. A check valve as in claim 1, wherein the protrusions are configured to permit fluid flow from the opening in the membrane disk to the exit passage.

3. A check valve as in claim 2, wherein the protrusions are generally circumferentially equally spaced.

4. A check valve as in claim 3, wherein the protrusions define a generally crown-shaped formation.

5. A check valve as in claim 4, wherein the protrusions and the second hose connector housing are a single, unitary component.

6. A check valve as in claim 1, wherein the coupled first and second hose connector housings define an annular groove of greater diameter than the annulus of the valve seat, and the membrane disk includes an annular protrusion, wherein the disk annular protrusion is configured to be received in the annular groove defined by the coupled first and second hose connector housings.

7. A check valve for liquid applications comprising:
a first hose connector housing defining an entry passage extending into an entry space at least partially defined by an annular valve seat;
a second hose connector housing coupled with the first hose connector housing, the second hose connector housing defining an exit passage, an outer rim, a plurality of supporting surfaces circumferentially about the exit passage, wherein each supporting surface includes a projection located within the diameter of the annular valve seat and extending generally toward the entry passage and further includes a first radial portion extending substantially along the radial distance between the exit passage and the outer rim, the supporting surfaces defining recesses therebetween, and at least one groove fluidly connecting at least one recess with the exit passage; and a generally flexible membrane disk clamped between the first and second hose connector housing such that the membrane disk engages the supporting surface projections to pretension the membrane disk against the valve seat and selectively engage the valve seat, the membrane disk defining at least one opening located radially outwardly from the valve seat, where the membrane disk is configured to be movable between a seated position, where the entry space and the recess are fluidly sealed from each other, and an unseated position, where the entry space and the recess are fluidly connected via the at least one opening such as to fluidly connect the entry passage with the exit passage;
wherein the membrane disk is positioned such that at least one membrane disk opening overlies at least one recess in the second hose connector housing and the membrane disk at the unseated position under high differential pressures engages the first radial portions and fluidly connects the entry space with the exit passage via the at least one membrane disk opening, the recess, and the groove in the second hose connector housing, and wherein the supporting surfaces each further define a second radial portion connected to the first radial portion adjacent the exit passage and extending across a portion of the radial distance between the exit passage and the outer rim, thereby defining a second recess between the first radial portion and second radial portion fluidly connected to the recess between supporting surfaces, wherein the membrane disk opening overlies the recess between the first and second radial portions such that the membrane disk and the unseated position under high differential pressures engages the first and second radial portions of the supporting surface projections to thereby fluidly connect the entry space with the exit passage via the membrane disk opening, the recess between the first and second radial portions, the recess between supporting surfaces and the groove in the second hose connector housing.

8. A check valve as in claim 7, wherein the second hose connector housing defines a plurality of recesses respectively positioned between adjacent supporting surfaces and a plurality of grooves each fluidly connecting one of the recesses with the exit passage.

9. A check valve as in claim 8, wherein the supporting surfaces each extend generally radially to the outer rim of the second hose connector housing.

10. A check valve as in claim 9, wherein the supporting surfaces define a broadening width along a direction toward an outer rim of the second hose connector housing.

11. A check valve as in claim 8, wherein each of the grooves is positioned between adjacent supporting surfaces.

12. A check valve as in claim 8, wherein the membrane disk defines a plurality of openings located radially outwardly from the valve seat and wherein each of the openings is generally kidney-shaped.

13. A check valve as in claim 12, wherein the second hose connector housing defines six supporting surfaces and the membrane disk defines eight openings.

14. A check valve as in claim 7, wherein the supporting surface projections are positioned on the inner end of the supporting surface and adjacent to the exit passage, and positioned within a radius of the valve seat.

15. A check valve as in claim 7, wherein the supporting surfaces each have at least a portion that define a generally concave surface.

16. A check valve as in claim 7, wherein the coupled first and second hose connector housings define an annular groove of greater diameter than the annulus of the valve seat, and the membrane disk includes an annular protrusion, wherein the disk annular protrusion is configured to be received in the annular groove defined by the coupled first and second hose connector housings.

17. A check valve as in claim 7, wherein the coupled first and second hose connector housings define an annular groove of greater diameter than the annulus of the valve seat, and the membrane disk includes an annular protrusion, wherein the disk annular protrusion is configured to be received in the annular groove defined by the coupled first and second hose connector housings.

18. A check valve as in claim 7, wherein the coupled first and second hose connector housings define an annular groove of greater diameter than the annulus of the valve seat, and the membrane disk includes an annular protrusion, wherein the disk annular protrusion is configured to be received in the annular groove defined by the coupled first and second hose connector housings.

19. A check valve as in claim 18, wherein the supporting surfaces each have at least a portion that define a generally concave surface.