WO2008019762A1

WO2008019762A1 - Non-return valve

Info

Publication number: WO2008019762A1
Application number: PCT/EP2007/006825
Authority: WO
Inventors: Kieran Costello
Original assignee: Filtertek B.V.
Priority date: 2006-08-17
Filing date: 2007-08-01
Publication date: 2008-02-21
Also published as: DE202006012645U1

Abstract

The invention relates to a non-return valve (1) with a rotationally symmetrical central part (2) which contains the valve seat (4) and which has an inlet duct (6) and, connected to the latter, outlet openings (14) and which is surrounded by an elastic collar (16) which covers the outlet openings (14) and forms the valve closing member. The non-return valve (1) is formed for medicinal purposes by virtue of the central part (2) being of conical design and the outlet openings (14) being inclined in the axial direction. The elastic collar (16) has a conical shape which approximately corresponds to the central part (2). The collar (16) is preloaded in a locally limited fashion against the upper part (18) of the central part (2).

Description

Filtertek B.V., Industrial Estate, Newcastlewest, County of Limerick, Ireland

Check valve .

The invention relates to a check valve with a rotationally symmetrical, the valve seat-containing central part, which has an inlet channel and associated with these outlet openings and which is surrounded by an elastic sleeve which covers the outlet openings and forms the valve closure member.

A check valve of this type is known, for example, from WO 2004/023010 A1, which is to be used, in particular, in media-carrying pressure lines, for example gas lines and the like, where the medium can have corrosive properties and the non-return valves customary for this purpose, in particular their springs, could damage. In this known valve, the outlet channels connected to the inlet channel of the middle part extend at right angles to the main axis of the inlet channel and also meet at right angles to the rubber sleeve covering their outlet openings, so that the media flow must be deflected twice at right angles when the check valve is open. Furthermore, the inlet channel in the central part ends, as it were, in a dead end, which represents a recirculation-causing media trap. For medical purposes, therefore, this known check valve is in no way suitable, since the two-time right-angle deflection of the media stream, for example in the case of blood, hemolysis or damage to the cells, would cause. Furthermore, the am End of the inlet channel provided, causing a recirculation trap for medical purposes of considerable disadvantage, since in this area dosages of a drug would be lost and there, if the liquid is blood, it could clot in the recirculation zone.

Another check valve of the type described above is known from DE-AS 1,200,623, which is to be used for example in vehicle hoses, inflatable containers and the like. In terms of its construction, this known check valve likewise has the above-mentioned disadvantages.

The invention is therefore based on the object, starting from a check valve of the type mentioned, this form such that it avoids the disadvantages mentioned above.

Starting from a check valve of the type mentioned above, this object is essentially achieved in that the check valve is designed for medical purposes by the central part is conical and the outlet openings are inclined in the axial direction, that the elastic sleeve one, the middle part about corresponding has conical shape, and that the cuff is biased locally against the upper end of the central part.

Apart from the complete solution of the above-mentioned object, the invention achieves the particular advantage that in this check valve, the pumped medium runs almost parallel to the flow in the inlet and outlet, so that it can not come to hemolysis or cell damage in the case of blood. In the known valve is added that the outlet channels have a much smaller diameter as the main intake port and thus constitute a throttle point and increase the pressure drop within the valve considerably. For medical applications, however, the pressure drop must be at a minimum. In the valve according to the invention, therefore, the additional advantage is achieved that the cross-sectional area of the flow path is made as uniform as possible, so that the majority of the pressure drop is formed only by the pressure required to open the localized area of the sleeve.

Furthermore, there is no recirculation area in the check valve according to the invention.

In a preferred embodiment of the invention is to provide that the upper end of the central part forms the valve seat. In this way, the advantage is achieved that the outlet openings of the inlet channel are clearly separated from the valve seat, which is formed by the upper end, so that thereby a further facilitation of the flow is achieved.

In detail, the invention can be further developed in that the middle part is formed integrally with a first housing half containing the axial inlet channel.

It is preferred that the sleeve has a radial annular skirt at its lower end.

The annular skirt is preferably supported on a, surrounding the middle part ring seat. In a particularly preferred embodiment, it is provided here that the annular skirt is clamped by an annular projection on a, an axial outlet channel containing the second housing half against the ring seat. In this way, the advantage is achieved that on the one hand, the assembly of the valve according to the invention is greatly facilitated and on the other hand at the same time by the likewise made of elastomeric material and formed integrally with the sleeve ring skirt, the two housing halves are sealed against each other. The check valve according to the invention therefore consists only of three parts, namely the two housing halves and the elastic sleeve.

Because of this design, the first half of the housing may preferably be connected to the second half of the housing by a simple snap connection, which of course is dimensioned such that a pressure sufficient for sealing is exerted on the annular skirt by the annular projection.

Alternatively, the housing halves can be joined together by ultrasonic welding or by gluing, since the two housing halves preferably consist of a corresponding plastic.

A particularly preferred embodiment according to the invention can be provided in that the collar has an annular bead on its inner side in the region prestressed against the upper end of the central part forming the valve seat. As a result, the necessary opening pressure can be further reduced by merely producing a line contact between the sleeve and the valve seat, which can be of considerable advantage for medical purposes. In detail, the invention can preferably be further developed in that the section of the middle section lying below the valve seat consists of supports extending conically to the valve seat, which separate the comparatively large outlet openings extending up to the valve seat. As a result, the advantage is achieved that from the combination of the conical orientation and the comparatively large outlet openings limiting columns of the flow cross-section through the valve remains almost constant.

Specifically, it can also be advantageous to form an integral annular bead on the upper end of the middle part, which forms the valve seat, opposite the locally prestressed region of the sleeve. This also offers the advantage that the check valve according to the invention closes under linear contact.

In the following the invention will be explained in more detail with reference to embodiments exemplified in the drawings. It shows:

FIGURE 1 is a greatly enlarged side view of a first embodiment of a check valve according to the invention;

FIG. 2 is a sectional view taken along line A-A of FIG. 1, illustrating the valve in the closed state;

FIGURE 3 is a view corresponding to Figure 2 of the valve in the open state;

FIG. 4 is a perspective view of a first housing part; FIG. 5 is a plan view of the housing part of FIG. 4;

FIG. 6 is a sectional view of a check valve according to a second embodiment of the invention in the closed state;

FIG. 7 is a view corresponding to FIG. 6 of the valve in the opened state;

FIG. 8 is a sectional view of another embodiment of a check valve according to the invention in the opened state;

FIG. 9 is a side view of a modified embodiment of the first housing part;

10 is a plan view of the first housing part according to Figure 9, and

FIG. 11 side views and sectional views of the individual parts of the non-return valve according to the invention according to the embodiment according to FIGS. 1 to 5.

Referring first to Figures 1 to 5, there is shown in greatly enlarged view a check valve according to the invention according to a first embodiment, wherein the check valve according to the invention can be used in both gravity conveying and pumping. The opening pressures of the valve of the invention are in the range of up to 20 cm of WS (between 1.5 and 5 psi), depending on the particular design. As can be seen in particular from FIGS. 1 and 2, the non-return valve 1 of the first embodiment according to the invention comprises a first housing half 10 and a second housing half 12, wherein a rotationally symmetrical middle part 2 contains the valve seat 4. The middle part 2 has an inlet channel 6, to which a coaxial outlet channel 8 connects in the second housing half 12. The middle part 2 has outlet openings 14 connected to the inlet channel 6 and is surrounded by an elastic sleeve 16, which is made of an elastomeric material. The collar 16 covers the outlet openings 14 and, in contrast to the above-mentioned prior art above the outlet openings 14, the valve closure member.

In order to make the check valve 1 suitable for medical purposes, the middle part 2 is designed to taper in the direction of its upper end 18, wherein the upper end 18 forming the valve seat 20 preferably has a lower conicity than the lower area 40.

Corresponding to the conicity, the outlet openings 14 are designed to be inclined in the axial direction, so that the flow through the valve 1 experiences virtually no deflection in the opened state.

The elastic sleeve 16 has one, the middle part 2 approximately corresponding conical shape. In an upper region corresponding to the valve seat 20, the sleeve 16 is biased in the axial direction locally against the upper end 18 of the central part 2, so that the upper end 18 forms the valve seat 20 and the prestressed area produces the actual closing member of the valve. As shown, the middle part 2 is formed integrally with the first housing half 10 containing the axial inlet channel 6, which is made of a suitable plastic by injection molding.

The sleeve 16 is provided at its lower end 22 with an integrally formed radial annular skirt 24, which is supported on a, the middle part 2 surrounding ring seat 26. The annular skirt 24 is clamped against the annular seat 26 by an annular, skirt-like projection 28 on the second housing half 12 containing the axial outlet channel 30. Since the annular skirt 24 is made of the same elastomeric material as the sleeve 16, the annular skirt 24 forms an effective seal between the two housing halves 10 and 12.

Consequently, the two housing halves 10 and 12 can be connected to one another in a media-tight manner by means of a simple snap connection illustrated in FIGS. 2 and 3, whereby it must be ensured that sufficient clamping pressure is exerted on the annular skirt 24 by appropriate dimensioning of the parts snapping into each other through the annular projection 28 is, so that it is pressed securely against the ring seat 26.

Alternatively, of course, the two housing halves 10 and 12 can be joined together by ultrasonic welding or by gluing or by another suitable method.

In the operating state of the check valve shown in Figure 2, a return flow from the outlet channel 8 to the inlet channel 6 is effective by the bias of the localized upper portion of the sleeve 16 against the valve seat 20 of the Upper end 18 and acting on the outside of the sleeve 16 prevents pressure.

In the illustrated in Figure 3 open state of the valve, the upper portion of the sleeve 14 is lifted together with the adjoining lower portion of the central part 2 and the valve seat 20 by the media pressure in the inlet channel 6, wherein the conveyed medium through the outlet openings 14 and can flow past the valve seat 20 into the outlet channel 30, respectively, without experiencing any significant deflection. The special design of the central part 2 makes it possible to form the outlet openings 14 correspondingly large. Preferably, the section 40 of the central part 2 located below the valve seat 20 is designed such that it consists of conically extending to the valve seat 20 supports 42 which extend to the lower edge of the valve seat 20 and thereby separate the corresponding likewise also to the valve seat 20 reaching outlet openings 14 from each other ,

In the embodiment according to FIGS. 1 to 5, four such supports 42 are provided, which correspondingly separate four large outlet openings 14 from each other.

The embodiment of the invention illustrated in FIGS. 6 and 7 corresponds in most details to the embodiment described above, so that reference may be made here to the above description, wherein the same reference numerals have been used for the same or equivalent parts.

In the embodiment according to FIGS. 6 and 7, the closed state of the valve 1 is shown in FIG. 6, while FIG. 7 shows the same view in the opened state. Instead of the snap connection, in this embodiment form the housing halves 10 and 12 by ultrasonic welding or gluing together, wherein the seal between the housing halves 10 and 12, as in the embodiment described above, additionally by the clamping of the annular skirt 24, the sleeve 16 against the annular seat 26 of the first housing half 10 ,

Notwithstanding the embodiment described above, the sleeve 16 is provided in the against the valve seat 20 forming O- berende 18 of the central part biased portion 34 on its inner side 38 with an annular bead 36 which forms a sealing ring. In this way, the seal in the closed state by a linear contact, whereby even more accurate values of the opening pressure of the check valve 1 can be achieved, which is particularly important in medical technology of particular importance.

The illustrated in Figure 8 embodiment of the check valve 1 in the open state corresponds in essential details of the embodiment according to Figures 6 and 7, so that reference can be made to the above description with respect to these details, wherein the same or like parts have been used like reference numerals.

Notwithstanding the embodiment according to FIGS. 6 and 7, in this exemplary embodiment an annular bead 44 is formed on the valve seat 20, which in turn ensures that a linear contact is achieved between the region of the sleeve 16 which is localized and prestressed against the upper end 18 of the middle part 2 is made in the closed state, which ensures a precise definition of the opening pressures. For better clarity, FIG. 9 and FIG. 10 show details of the first housing half 10, as can be used in the exemplary embodiment according to FIG. As shown, the annular bead 44 is integrally formed with the valve seat 20 forming upper end 80 of the central part 2. Furthermore, it can be seen from FIGS. 9 and 10 that in this embodiment only three supports 42 are provided in order to delimit the outlet openings 14, so that they can be increased again in order to achieve a uniform flow cross-section.

Figure 11 shows again in side view and sectional view and about twice as large as the check valve 1 according to the invention only three components, namely the first housing part 10, the sleeve 16 and the second housing part 12 is buildable. It will be appreciated that, apart from the advantages of flow routing, the conicity of the central portion 2 and the cuff 16 greatly facilitate the automated assembly of such valves by allowing the cuff 16 to be easily slipped onto the midportion 2, in the manufacture of the snap fit between the housing parts 10 and 12 at the same time the annular skirt 24 is pressed against the ring seat 26 and further at the same time the upper, localized portion of the sleeve 16 is pulled under bias on the valve seat 20.

Some embodiments of a check valve according to the present invention have been described above, and changes and modifications will be apparent to those skilled in the art without departing from the spirit of the invention. All features and advantages of the invention, including design details and spatial arrangements, which emerge from the description, the claims and the drawings, can be essential to the invention both individually and in any desired combination.

LIST OF REFERENCE NUMBERS

= Check valve = middle section = valve seat = inlet channel = outlet channel = first housing half = second housing half = outlet openings = cuff = upper end of 2 = valve seat = lower end of 16 = annular skirt = ring seat = annular projection = outlet channel = snap connection = area = annular bead = inside of 34 = Section = support = annular bead on 20

Claims

20.07.2007BET-out 132 PCTFiltertek BV, Industrial Estate, Newcastlewest, County of Limerick, IrelandPATENTIAL CLAIMS

1. A check valve (1) with a rotationssytnmetrischen, the valve seat (4) containing central part (2) having an inlet channel (6) and associated with these outlet openings (14), and which is surrounded by an elastic sleeve (16) covering the outlet openings (14) and forming the valve closing member, characterized in that the check valve (1) is designed for medical purposes, in that the central part (2) is conical and the outlet openings (14) are inclined in the axial direction, that the elastic Cuff (16) the central part (2) has approximately corresponding conical shape, and that the sleeve (16) locally biased against the upper part (18) of the central part (2) is biased.

2. Check valve according to claim 1, characterized in that the upper end (18) of the central part (2) forms the valve seat (20).

3. Non-return valve according to claim 1 or 2, characterized in that the central part (2) is formed integrally with a, the axial inlet channel (6) containing the first housing half (10).

4. Check valve according to claim 3, characterized in that the sleeve (16) at its lower end (22) has a radial annular skirt (24).

5. Check valve according to claim 4, characterized in that the annular skirt (24) on one, the middle part (2) surrounding the annular seat (26) is supported.

6. Non-return valve according to claim 4 or 5, characterized in that the annular skirt (24) by an annular projection (28) on a, an axial outlet channel (30) containing second housing half (12) is clamped against the annular seat (26).

7. Check valve according to claim 6, characterized in that the first housing half (10) with the second housing half (12) by a snap connection (32) is connected.

8. Check valve according to claim 6, characterized in that the first housing half (10) with the second housing half (12) is connected by ultrasonic welding.

9. Check valve according to claim 6, characterized in that the first housing half (10) with the second housing half (12) is connected by gluing.

10. Check valve according to one of the preceding claims, characterized in that the sleeve (16) in the against the valve seat (4) forming upper end (18) of the central part (2) biased region (34) has an annular bead (36) on its inside (38).

11. Check valve according to one of the preceding claims, characterized in that the below the valve seat (4) lying portion (40) of the central part (2) by conically to the valve seat (4) extending supports (42), which up to the valve seat (4) separating, relatively large outlet openings (14) from each other.

12. Check valve according to one of the preceding claims 1 to 9 and 11, characterized in that the valve seat (20) forming the upper end (18) of the central part (2) in which the limited prestressed region (34) of the sleeve (16) opposite one another one-piece annular bead (44).