GB2107025A

GB2107025A - Fluid flow control valve

Info

Publication number: GB2107025A
Application number: GB08135830A
Authority: GB
Inventors: Wakichi Takemoto
Original assignee: Kitamura Valve Manufacturing Co Ltd
Current assignee: Kitamura Valve Manufacturing Co Ltd
Priority date: 1981-09-28
Filing date: 1981-11-27
Publication date: 1983-04-20
Also published as: CA1193588A; FR2513725B1; IT8123922V0; JPS5854276A; GB2107025B; DE3205617C2; IT1140408B; NO823256L; FR2513725A1; IT8125888A0; DE3205617A1; AU8840082A

Abstract

A fluid flow control valve wherein a bored ball (3) is pivotally mounted within the valve body (1) on a stem (4), in contact with annular valve seats (8) arranged between the ball and the valve body, and a coil spring (9) is fitted in each annular channel (10) between the valve body and the valve seats. The coils of the spring (9) are inclined in the same direction, and each spring is elastically distorted without changing its length when it is compressed from its opposite longitudinal sides, so that, in their distorted form, the springs urge the annular valve seats into sealing engagement with the ball. <IMAGE>

Description

SPECIFICATION Fluid flow control valve This invention relates to fluid flow control valves of the plug-cock type incorporating a bored ball-like plug pivotally mounted in the valve body.

In conventional valves of this kind, valve seats are held by seat retainers and each seat is urged into sealing engagement with the bored ball by an annular plate spring or a plurality (usually tens or scores) of coil springs. The coil springs are arranged between the seat retainers and the valve body at certain intervals around the periphery of the seat retainers, and the one ends of the springs are inserted in holes formed in the inner surface of the valve body.

However, when plate springs are used, it is difficult to manufacture them, and since the processing cost is high, the manufacturing cost becomes very high especially when a high-grade or costly material is used; further, different sizes of such springs are required depending on the diameter sizes of the valve. When coil springs are used, it is difficult to manufacture the valve body, and a plurality of coil springs are required, their assembly operations involving considerable time and trouble, and thus high cost.

It is an object of the present invention to provide a valve of the kind described, which is compact and simple in construction and capable of being manufactured at low cost, and in which the aforementioned disadvantages are at least reduced.

According to the present invention there is provided a fluid-flow control valve wherein a bored ball is pivotally mounted within the valve body, on a stem and in contact with annular valve seats arranged between the ball and the valve body, characterised in that a coil spring extends along an annular channel between the valve body and each valve seat, the coils of the spring each being inclined in the same direction with respect to the perpendicular to the central longitudinal axis of the coil spring, and each being elastically compressed from its opposite longitudinal sides so that the annular valve seats are urged into engagement with the ball.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings in which: Fig. 1 is a central longitudinal cross-section through a valve according to the present invention; Fig. 2 is an enlarged view of the area A of Fig. 1; and, Fig. 3 is a developed view along the line Ill-Ill of Fig. 2.

Referring to the drawings, there is shown in Fig. 1 a fluid-flow control valve according to the present invention.

Valve body 1 comprises a body cap 1 a and a body member 1 b, which are coupled by bolts 2. A bored ball 3 is pivotally mounted in the body member 1 b on a vertical operating stem 4.

A pair of valve seat retainers 5 are movably fitted in annular recesses 6 cut in the inner surface of the valve body in left and right side parts of valve chamber 1 c, and in left and right fluid paths id and le of the valve body 1.

Each retainer 5 is provided with an annular groove 7 in its inner side, facing the bail 3, in which a valve seat or sealing ring 8 is fitted. A thin cylindrical flange 5a, having the same coaxial diameter as the fluid paths 1 d and 1 e, extends integrally and horizontally from the outer end of the seat retainer 5.

A coil spring 9 whose coils or loops are inclined in the same direction with respect to the perpendicular to the central axis of the coil spring, in the form of saw's teeth, is clearly shown in Fig. 3. When this spring is compressed, from its opposite longitudinal sides, in the direction perpendicular to the central axis of the coil spring (and parallel to the flow path), it can be elastically distorted or flattened without changing its entire length, and its biasing force thus depends on its length.

Inclined-coil springs 9, of appropriate length, are fitted in annular space or channel 10 of each annular recess 6, which is enclosed by the valve body 1 and by the seat retainer 5, and the springs urge the valve seat 8 against the ball 3. Spacers 11 are arranged between the ends of the inclinedcoil springs 9.

It will be understood from the above description that, since the biasing forces on the seat retainers 5 are derived from the inclined-coil springs 9 described above, the desired bias force can readily be obtained by varying the number of the springs 9 and the sum of their lengths.

Therefore, the same kind of inclined-coil spring can be employed, by appropriately cutting to lengths, for various valves having different diameters, for seat retainers to be biased for different pressures of fluid flow, and for valve seats of different materials.

According to the present invention, it has been found that two kinds of inclined-coil springs, having two different loop diameters, fully cover valves having diameters of from 5 to 50 centimetres.

Since the inclined-coil springs have a very strong elastic restitution force, they can be made from a finer coil material than is usual, and can thus be manufactured easily and at low cost even when high-grade materials are used.

Further, the production of the valve body is simple, and the spaces occupied by the inclined coil springs are sufficiently small enough to provide a compact valve body, which also means low manufacturing cost.

According to the present invention, one or a plurality of inclined-coil springs may provide the annular form, without using any spacers 11.

1. A fluid-flow control valve wherein a bored ball is pivotally mounted within the valve body, on a stem and in contact with annular valve seats

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Fluid flow control valve This invention relates to fluid flow control valves of the plug-cock type incorporating a bored ball-like plug pivotally mounted in the valve body. In conventional valves of this kind, valve seats are held by seat retainers and each seat is urged into sealing engagement with the bored ball by an annular plate spring or a plurality (usually tens or scores) of coil springs. The coil springs are arranged between the seat retainers and the valve body at certain intervals around the periphery of the seat retainers, and the one ends of the springs are inserted in holes formed in the inner surface of the valve body. However, when plate springs are used, it is difficult to manufacture them, and since the processing cost is high, the manufacturing cost becomes very high especially when a high-grade or costly material is used; further, different sizes of such springs are required depending on the diameter sizes of the valve. When coil springs are used, it is difficult to manufacture the valve body, and a plurality of coil springs are required, their assembly operations involving considerable time and trouble, and thus high cost. It is an object of the present invention to provide a valve of the kind described, which is compact and simple in construction and capable of being manufactured at low cost, and in which the aforementioned disadvantages are at least reduced. According to the present invention there is provided a fluid-flow control valve wherein a bored ball is pivotally mounted within the valve body, on a stem and in contact with annular valve seats arranged between the ball and the valve body, characterised in that a coil spring extends along an annular channel between the valve body and each valve seat, the coils of the spring each being inclined in the same direction with respect to the perpendicular to the central longitudinal axis of the coil spring, and each being elastically compressed from its opposite longitudinal sides so that the annular valve seats are urged into engagement with the ball. An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings in which: Fig. 1 is a central longitudinal cross-section through a valve according to the present invention; Fig. 2 is an enlarged view of the area A of Fig. 1; and, Fig. 3 is a developed view along the line Ill-Ill of Fig. 2. Referring to the drawings, there is shown in Fig. 1 a fluid-flow control valve according to the present invention. Valve body 1 comprises a body cap 1 a and a body member 1 b, which are coupled by bolts 2. A bored ball 3 is pivotally mounted in the body member 1 b on a vertical operating stem 4. A pair of valve seat retainers 5 are movably fitted in annular recesses 6 cut in the inner surface of the valve body in left and right side parts of valve chamber 1 c, and in left and right fluid paths id and le of the valve body 1. Each retainer 5 is provided with an annular groove 7 in its inner side, facing the bail 3, in which a valve seat or sealing ring 8 is fitted. A thin cylindrical flange 5a, having the same coaxial diameter as the fluid paths 1 d and 1 e, extends integrally and horizontally from the outer end of the seat retainer 5. A coil spring 9 whose coils or loops are inclined in the same direction with respect to the perpendicular to the central axis of the coil spring, in the form of saw's teeth, is clearly shown in Fig. 3. When this spring is compressed, from its opposite longitudinal sides, in the direction perpendicular to the central axis of the coil spring (and parallel to the flow path), it can be elastically distorted or flattened without changing its entire length, and its biasing force thus depends on its length. Inclined-coil springs 9, of appropriate length, are fitted in annular space or channel 10 of each annular recess 6, which is enclosed by the valve body 1 and by the seat retainer 5, and the springs urge the valve seat 8 against the ball 3. Spacers 11 are arranged between the ends of the inclinedcoil springs 9. It will be understood from the above description that, since the biasing forces on the seat retainers 5 are derived from the inclined-coil springs 9 described above, the desired bias force can readily be obtained by varying the number of the springs 9 and the sum of their lengths. Therefore, the same kind of inclined-coil spring can be employed, by appropriately cutting to lengths, for various valves having different diameters, for seat retainers to be biased for different pressures of fluid flow, and for valve seats of different materials. According to the present invention, it has been found that two kinds of inclined-coil springs, having two different loop diameters, fully cover valves having diameters of from 5 to 50 centimetres. Since the inclined-coil springs have a very strong elastic restitution force, they can be made from a finer coil material than is usual, and can thus be manufactured easily and at low cost even when high-grade materials are used. Further, the production of the valve body is simple, and the spaces occupied by the inclined coil springs are sufficiently small enough to provide a compact valve body, which also means low manufacturing cost. According to the present invention, one or a plurality of inclined-coil springs may provide the annular form, without using any spacers 11. CLAIMS

1. A fluid-flow control valve wherein a bored ball is pivotally mounted within the valve body, on a stem and in contact with annular valve seats arranged between the ball and the valve body, characterised in that a coil spring extends along an annular channel between the valve body and each valve seat, the coils of the spring each being inclined in the same direction with respect to the perpendicular to the central longitudinal axis of the coil spring, and each being elastically compressed from its opposite longitudinal side so that the annular valve seats are urged into engagement with the ball.

2. A ball valve as claimed in Claim 1, wherein each coil spring comprises a plurality of end-toend spring lengths.

3. A ball valve as claimed in Claim 1, wherein each coil spring comprises one endless spring.

4. A ball valve as claimed in any preceding Claim, wherein each valve seat is urged towards the bored ball via an annular seat retainer which hoids the valve seat.

5. A fluid-flow control valve, substantially as hereinbefore described with reference to the accompanying drawings.

6. The features herein disclosed, or their equivalents, in any novel selection.