GB2215010A - Fluid valve - Google Patents

Abstract

A one-way fluid valve comprises a valve body 13 (14) having therein a generally annular valve seat 19 (23), a valve member 15, 16, (25, 26) having a face shaped to engage the valve seat, and at least three elongated projections 22 extending in parallel from the valve member from points radially within the seat-engaging face, the valve member being mounted in the valve body for linear movement towards and away from the valve seat in a direction parallel to the projections. Each projection may be arcuate or circular in cross section. <IMAGE>

Description

PWID VALVE The present invention is a novel form of one-way valve for controlling the flow of a fluid.

One-way valves hitherto available have taken a wide variety of forms and are used in a wide range of applications.

One form of axial-f low fluid valve comprises a valve member mounted for linear movement in an axial direction relative to an annular valve seat. The linear movEment of the valve member is usually determined either by a rigid shaft upon which the valve member is fixedly mounted, which shaft is able to reciprocate axially in a suitable channel, or by mounting the valve member slidably on a fixed shaft. However the need for such a fixed shaft or a mounting for a reciprocating shaft introduces limitations into the design of the valve assembly and may also impede the flow of fluid through the valve.

It is an object of the present invention to provide a novel form of valve which has one or more advantages in certain applications over alternative valves which are available.

The valve according to the present invention comprises a valve body having therein a generally annular valve seat, a valve mEmber having a face thereof shaped to engage said generally annular valve seat, and at least three elongated projections extending in parallel alignment fran said valve member from points radially within said seat-engaging face, said valve member being mounted within said valve body for linear movement towards and away fran said valve seat in a direction parallel to the length of said projections.

The at least three projections may take the place of a shaft for mounting the valve member but preferably a generally cylindrical shaft is provided which extends from the valve member in the opposite but parallel direction to the projections.

The projections may nonetheless form the main guide defining the linear finrearsrtt of the valve member, either replacing the guide afforded by a shaft support or supplementing it as desired.

The at least three projections are preferably syTErtetrically placed around the inner circumference of the seat-engaging surface and are preferably all disposed at the same radial distance from the axis thereof. In a preferred form of the valve, the generally annular valve seat forms one end of a hollow cylindrical fluid passage through the valve and the projections are so disposed as to slidably engage the concave inside face of the cylindrical passage. In this form of the valve, the projections may each have a curved radially outer face which may, as desired, conform to a greater or lesser extent to the curvature of that concave inside face. Thus the projections may be circular in transverse cross-section or may be arcuate in such cross-section.

In general, it is preferred to provide just three such elongated projections and these are sufficient to guide the valve member and maintain it in an axially. central position relative to the valve seat. However one or more additional projections may be provided to afford even greater control over the position and linearity of movement of the valve member.

The valve member nray be minted freely for movement towards or away fram the valve seat determined solely by the pressure of fluid on each side of the valve member. Hbwever in many applications, readily recognised by those skilled in the art, it is necessary or desirable to urge the valve member positively towards a closed or open position in the absence of specific pressure in the fluid flowing through the valve. This may readily be achieved by providing an extension or compression: spring acting upon the valve member, especially a compression spring urging the valve member into engagement with the valve seat.

The invention will now be further described with reference to the accompanying drawings, wherein:- Fig. 1 is a vertical sectional view of a double-acting pump incorporating two preferred forms of the onemy valve according to the present invention; Fig. 2 is a transverse sectional view taken along the line II-II of Fig. 1, shewing one form of the projections which are a feature of the valve of the present invention; and Fig. 3 is a view ccrresponding to Fig. 2, showing an alternative form of the projections.

The illustrated double-acting pump, which is described in detail in a cop ending application filed on the saze date as this present application, canprises a piston 4 reciprocating in a cylinder 5 upon a shaft 6 driven by an air cylinder (not shown).

By reciprocation of the piston 4, a fluid product is pumped fram an inlet 7 to an outlet 8 via two routes alternately. One of the fluid flow routes catprises tabular conduits 9 and 10 and that part of the cylinder 5 which is on the side of the piston 4 remote frcm the shaft 6. The other fluid flow route ccmprises tubular conduits 11 and 12 and that part of the cylinder 5 which is on the shaft side of the piston 4.

Fluid flow through the pump is controlled by inlet valves and a double outlet valve mounted in valve bodies 13 and 14 respectively. Within the inlet valve body 13 are two valve members 15 and 16, each supported upon a shaft for reciprocal linear movement towards and away fran an annular valve seat.

The valve member 15 is mounted upon a shaft 15a which slides within a cross-member 17. A helical spring 18 acting between the valve member 15 and the cross-member 17 urges the valve member into engagement with an annular valve seat 19. The other inlet valve member 16 is similarly urged into engagement with an annular valve seat 20.

The central portion of the interior length of the valve body 13 forms a cylindrical concave face 21 extending betwEen the valve seats 19 and 20. Projecting fran the front of each of the valve members 15 and 16 into the space between the two valve seats are elongated guides 22 (three on each valve member).

As shown in enlarged cross-sectional detail in Fig. 2, the guides 22 are each arcuate in cross-section and are of similar curvature to the adjacent face 21. These guides 22 assist the shaft upon which the associated valve member is supported in keeping the valve member axially centralised with respect to the corresponding valve seat.

Fig. 3 shows an alternative cross-sectional shape for the guides 22.

The outlet valve body 14 has two annular valve seats 23 and 24, facing each other across the interior of the valve body. Between the valve seats and axially disposed with respect to the valve seats are located two valve mEmbers 25 and 26. Each of the valve members has an inclined annular surface on its forward. face, of such shape and dimensions as to mate closely with the associated valve seat. From each said forward face, within the inner circumference of the inclined annular surface, three linear projections extend, similar to the projections 22 of Fig. 2. The projections are a close sliding fit within cylindrical chambers 27 and 28 in the valve body 14.

On the rear face of the valve member:25 is a hollow shaft 29, into which a solid shaft 30 on the rear face of the valve member 26 projects. A helical spring 31 encircles the shaft 30 and is located within the hollow shaft 29 and thereby urges the two valve members 25 and 26 apart into contact with the respective valve seats 23 and 24. The projections from the faces of these two valve members hold the valve members in alignment with the valve seats throughout operation of the valve.

It can be seen that, while the projections 22 are of assistance in the operation of the inlet valves of the illustrated double-acting pump, they are essential to the operation of the double outlet valve, since the valve members 25 and 26 would simply be displaced fran alignment without then.

The use of the valves according to the present invention has been exemplified as applied to a double-acting pump but the valves are equally suitable for use in other contexts, especially where precise operation of the valves is important.

Claims (11)

1. A one-way fluid valve comprising a valve body having therein a generally annular valve seat, a valve member having a face thereof shaped to engage said generally annular valve seat, and at least three elongated projections extending in parallel alignment from said valve member from points radially within said seat-engaging face, said valve member being mounted within said valve body for linear movement towards and away fran said valve seat in a direction parallel to the length of said projections.

2. A one-way fluid valve as claimed in claim 1, wherein the at least three projections are symmetrically disposed around the inner circumference of the seat-engaging face.

3. A one-way fluid valve as claimed in claim 1 or claim 2, wherein the projections are disposed at the same radial distance from the axial centre of the seat-engaging face.

4. A one-way fluid valve as claimed in any of the preceding claims, wherein the generally annular valve seat forms one end of a hollow cylindrical fluid passage through the valve and the projections are so disposed as to slidably engage the concave inside face of the passage.

5. A one-way fluid valve as claimed in claim 4, wherein the projections each have a curved radially outer face.

6. A one-way fluid valve as claimed in claim 5, wherein the projections are arcuate in transverse cross-section and conform at least to sane extent to the curvature of the inside face of the fluid passage.

7. A one-way fluid valve as claimed in claim 5, wherein the projections are circular in transverse cross-section.

8. A one-way fluid valve as claimed in any of the preceding claims, wherein the valve mfmber is urged into engagement with the valve seat by a spring.

9. A one-way fluid valve as claimed in any of the preceding claims, wherein a generally cylindrical shaft extends fran the valve member in the opposite but parallel direction to the projections.

10. Tws fluid valves as claimed in claim 9, mounted back-to-back upon telescopically overlapping shafts.

11. A one-way fluid valve substantially as hereinbefore described with reference to, and as illustrated in, the acccmpanying drawings.