WO2000068603A1

WO2000068603A1 - Stop valve

Info

Publication number: WO2000068603A1
Application number: PCT/IB2000/000632
Authority: WO
Inventors: Bogdan Bogdanovic
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-05-11
Filing date: 2000-05-11
Publication date: 2000-11-16
Anticipated expiration: 2001-11-11
Also published as: AU4601000A

Abstract

A stop valve includes a mechanism (36) that controls fluid flow through a conduit (12) by pinching closed a flexible tube (42) through which the fluid passes. The mechanism of the stop valve does not contact the fluid flowing through the valve and thus does not deteriorate from prolonged exposure.

Description

STOP VALVE

BACKGROUND OF THE INVENTION

This invention relates to stop valves.

Stop valves are typically inserted in pipes to control a flow of fluid through the pipe. Typically, flow is stopped to service the pipe or to service connected fittings such as sinks and toilets.

Existing stop valves rely on O-rings and metal fittings which are in direct contact with the fluid flowing through the pipe. After prolonged contact (eg. ten years), the fluid often degrades the stop valve components which contact the medium. For example, liquids may be corrosive, causing metal parts to rust or O-rings to swell or fail. Liquids may contain minerals which build up and block the operation of the valve. In the case of gaseous fluids, the gas may dry out O-rings or lead to corrosion.

When stop valves fail, the valve might not close properly. Another common failure is that the valve becomes stuck closed. In either situation, the stop valve will need to be replaced. Replacement of stop valves may be particularly difficult because, when the stop valve is removed, nothing remains to stop flow during the replacement process. SUMMARY OF THE INVENTION

According to the invention there is provided a valve for controlling a flow of a fluid which comprises:

a housing defining first and second openings;

a flexible tube defining a conduit in the housing between the first and second openings through which fluid can flow; and

an operating mechanism including an actuator movable transversely relative to the conduit between a first position in which it pinches the tube closed and a second position adjacent to the tube in which the conduit is substantially unobstructed.

The housing may be T-shaped, with an in-line section defining the first and second openings and in which the tube is located, and an intersecting section extending transversely to the in-line section in which the actuator is movable.

Preferably, actuator is cylindrical and has a first end which is rounded complementally to the shape of the tube.

In a preferred embodiment, the end of the actuator is hemispherical and its curvature corresponds to the internal diameter of the tube.

The operating mechanism may comprise an operating member threadedly engaged with the intersecting section and in contact with a second end of the actuator, so that rotation of the operating member causes the actuator to extend or retract, thereby to pinch closed or release the tube.

A locating formation may be formed in the in-line section at one end thereof for retaining the tube in position therein.

The locating formation preferably comprises a frusto-conical formation with an aperture therein, the tube being a tight fit thereon around the aperture. The housing and the operating mechanism may be formed from a tough plastics material, while the tube is preferably formed from a flexible, resilient plastics material.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a front, cross-sectional view of the housing of a stop valve of the invention;

Figure 2 is a front, cross-sectional view of a cap of the valve;

Figure 3 is a top view of the cap;

Figure 4 is a front view of a plunger of the valve;

Figure 5 is a front cross-sectional view of a flexible tube of the valve;

Figure 6 is a front, cross-sectional view of a version of the stop valve housing with an elbow formed integrally with the housing; and

Figure 7 is a front, cross-sectional view of the assembled stop valve using the housing of Figure 6.

DESCRIPTION OF EMBODIMENTS

The invention provides a stop valve for controlling a flow of fluid such as a gas or liquid, and comprises a T-shaped housing, a flexible conduit or tube within the housing, and an actuator or plunger for compressing the tube, with a cap or knob which controls the plunger.

Figures 1 to 6 show the various components of a stop valve of the invention, while Figure 7 shows the assembled valve in section.

Referring first to Figure 1 , the T-shaped housing 10, which may be formed of metal or a tough plastics material, has an in-line tubular section 12 and an intersecting tubular section 14 which extends transversely substantially from, and perpendicular to, the longitudinal axis of the in-line section 12. The in-line section 12 has first and second opposed ends 16 and 20 which are provided with external threads 20 and 22 to permit connection of the housing to piping or other fittings. It will be understood that the dimensions of the housing and the characteristics of the threads will be determined partly by the application for which the valve is intended, and the piping or other fittings to which the valve will be connected in use.

An annular ring or baffle 24 with an upstanding frusto-conically shaped central boss 26 is located in the end 18 and defines an aperture 28 which is coaxial with the longitudinal axis of the in-line section 12 of the housing. The purpose of this formation is explained below. The ring or baffle 24 can be formed integrally with the in-line section 12, or could be an insert which is screwed, glued or welded into position.

Figures 2 and 3 show a cap or control knob 30 which is formed with an internal thread 32 which is complemental to an external thread 34 formed on the outer end of the intersecting section 14 of the housing, so that the cap can be screwed up and down on the longitudinal axis of the intersecting section, and thus displaced transversely relative to the longitudinal axis of the in-line section of the housing.

A plunger 36 is shown in Figure 4 and is seen to comprise a generally cylindrical elongate body with first and second opposed ends 38 and 40 which are rounded hemispherically.

Figure 5 shows a flexible tube 42 having opposed first and second ends 44 and 46 which is received in the housing 10 and through which fluid flows in use.

Figure 6 shows an alternative version of the housing 10, formed in this case with an integral elbow section 46 which is connected to the end of the in-line section 12 of the housing adjacent the ring or baffle 24 and which has an outlet 48.

Referring now to Figure 7, the assembled valve is shown in section. It can be seen that the flexible tube 42 is received within the in-line section 12 of the housing, with its end 46 in tight, sealing engagement with the outer edges of the frusto-conical locating formation 26 of the ring 24. In use, a fitting connected to the end 16 of the housing will prevent the tube from moving away from the locating formation. Preferably, fluid flow through the valve is from right to left in Figure 7, so that thelocating formation effectively prevents fluid from entering the housing, past the end of the tube.

The plunger 36 is received slidably within the bore of the intersecting section 14, and extends beyond the end thereof. The cap 30 is screwed onto the threads 34 of the intersecting section 14, so that rotary motion of the cap causes it to move towards or away from the in-line section 12. When the cap 30 is screwed down, the inner surface of the cap bears on the upper end 38 of the plunger, forcing the lower end 40 of the plunger into contact with the outer surface of the flexible tube 42. The further the cap is screwed down, the further the plunger intrudes into the bore of the in-line section 12, compressing the tube and gradually pinching it off. The curvature of the end 40 of the plunger is similar to and preferably the same as the internal diameter of the flexible tube 42, so that the tube can be pinched shut with a minimum amount of force being applied by the cap 30 to the plunger.

It will be appreciated that the upper end 38 of the plunger must extend sufficiently far beyond the end of the section 14 (or the cap 30 must have a formation which extends into the bore of the section 14) and the travel permitted by the complemental threads 34 of the section 14 and the threads 32 of the cap 30 must be sufficient to move the plunger between a position in which it permits unobstructed flow through the tube 42, and a position in which the plunger pinches the tube fully shut with sufficient force to prevent fluid flow through the tube at the working pressure of the valve. The tube 42 is preferably formed from a material which is sufficiently resilient to resume its tubular shape readily when the plunger is retracted.

In a preferred embodiment of the valve, the housing 10 was moulded from acetal plastics material, while the cap or knob 30 and the plunger 36 were moulded from ABS plastics, both suitably hard and tough for the purpose. The tube 42 was formed from a flexible plastics material such as Alcryn (trade mark) which is resistant to chemical attack and is suitably tough and resilient for the described application. It will be appreciated that other materials could be used, according to the intended application of the valve. For example, the housing 10 could be cast from a suitable metal, and the plunger 36 could also be metal. Because fluid passing through the valve does not come into contact with the moving parts of the valve, the valve is resistant to corrosion, or failure due to a build up of minerals or other solids.

Claims

1. A valve for controlling a flow of a fluid which comprises:

a housing defining first and second openings;

2. A valve according to claim 1 wherein the housing is T-shaped, with an in-line section defining the first and second openings and in which the tube is located, and an intersecting section extending transversely to the in-line section in which the actuator is movable.

3. A valve according to claim 2 wherein the actuator is cylindrical and has a first end which is rounded complementally to the shape of the tube.

4. A valve according to claim 3 wherein the end of the actuator is hemispherical and its curvature corresponds to the internal diameter of the tube.

5. A valve according to any one of claims 2 to 4 wherein the operating mechanism comprises an operating member threadedly engaged with the intersecting section and in contact with a second end of the actuator, so that rotation of the operating member causes the actuator to extend or retract, thereby to pinch closed or release the tube.

6. A valve according to any one of claims 2 to 5 wherein a locating formation is formed in the in-line section at one end thereof for retaining the tube in position therein.

7. A valve according to claim 6 wherein the locating formation comprises a frusto-conical formation with an aperture therein, the tube being a tight fit thereon around the aperture.

8. A valve according to any one of claims 1 to 7 wherein the housing and the operating mechanism are formed from a tough plastics material.

9. A valve according to any one of claims 1 to 8 wherein the tube is formed from a flexible, resilient plastics material.