GB2160621A

GB2160621A - Valve operating mechanisms

Info

Publication number: GB2160621A
Application number: GB8413896A
Authority: GB
Inventors: Arthur Leighton Brake; Derek Charles Grocott
Original assignee: Baj Vickers Ltd
Current assignee: Baj Vickers Ltd
Priority date: 1984-05-31
Filing date: 1984-05-31
Publication date: 1985-12-24
Also published as: GB8413896D0; GB2160621B

Abstract

An operating mechanism for controlling the valve of a compressed gas bottle comprises a valve- opening probe 8 mounted to move on a screw-threaded member. As shown probe 8 is advanced by means of a screw-jack 14 either by manual rotation of a wheel 12 or by an electric motor 22 through a reduction gearing. The neck of the bottle is preferably retained in position by a spring-loaded pince- nez latch (25, 26, Fig. 6) which, when the probe is advanced, is prevented from opening by a detent 24 coupled to the screw-jack mechanisms; thus the detent prevents coupling of a new bottle while the probe is advanced and prevents removal of a coupled bottle while the probe is advanced. <IMAGE>

Description

SPECIFICATION Valve The present invention relates to valves. More particularly the present invention relates to a valve operating mechanism. The present invention also extends to a valve and its operating mechanism, to a coupling mechanism and to a valve and its coupling mechanism and is suitable for gas stored at high pressure, especially when release of the high pressure gas is used as a source of energy.

According to one aspect of the present invention a valve operating mechanism for movement of a probe to open or close the valve in which the probe is mounted to move on a threaded member. Movement of the probe may be effected either manually or electrically. Manual operation may be via a wheel, rotation of which effects axial movement of the probe. Electrical operation may for example be via a motor, such as a 28 volt DC motor, which can be operated by a push button control mechanism. Whether manually or electrically operated the movement of the probe may be through a geared wheel. In this way by adjustment of the gearing ratio opening or closing movement of the valve can be brought about with a suitable power requirement. A gearing ratio of between 1 5:1 and 20:1, such as 18:1, is suitable.

The valve operating mechanism of the present invention is particularly useful for operating a valve in which the probe has three positions: probe fully extended into the valve to open the valve and release pressure, probe fully retracted to close the valve and an intermediate vent position in which residual pressure is vented to the atmosphere.

According to a second aspect of the present invention a release arrangement, preferably a finger latch quick release mechanism is supplied for connecting a valve and its operating mechanism to a gas container which is conveniently made through an adaptor valve in the neck of the gas container. A form of release arrangement comprises a scissor or pince-nez arrangement with a pivot between the ends, the arms at one end biased inwardly. The arms at the end holding the container are biased inwardly either directly or by biasing the opposite end outwardly. Release of the container is conveniently made by inward movement at the ends of the arm distant from the container preferably by means of a finger operated quick release mechanism.The ends of the arms engaging the container preferably have detents which engage cooperating slots, either in the neck of the container itself or in the adaptor valve in the neck of the container.

This provides a positive locking with the container.

The release arrangement according to the second aspect of the present invention may usefully be combined with the valve operating mechanism according to the first aspect of the present invention.

According to a third aspect of the present invention a valve operating mechanism may have a detent bar to prevent operation of the valve under certain conditions. This aspect of the invention may be combined with either of the first or second or first and second aspects of the present invention. When in combination with the first aspect of the present invention it can be used to prevent opening of the valve and subsequent release of pressure before the operating mechanism is properly positioned by preventing its attachment and opening of the valve with the probe in the extended position.

Such a detent bar may be conveniently used with a geared operating device when it may be directly linked to the gearing for operating the probe so that it is driven from the intermediate gear. This may then act as a stop preventing positioning of the valve operating device whilst the probe is extended in the pressure release position. The probe must be first retracted into the valve closed position before it can be fixed to the container.When in combination with the second aspect of the present invention the detent bar preferably cooperates with the finger operated release mechanism to prevent the operating mechanism from attaching to the container whilst the detent bar is engaged and necessitating its withdrawal for positioning the mechanism and once positioned to engage the release mechanism and lock it in the non-release position preventing withdrawal until the detent bar is itself withdrawn.

Thus a combination of all three aspects of the present invention prevents coupling with the container whilst the probe is extended thus preventing an inadvertent release of pressure, prevents removal of the cylinder before the probe has been withdrawn and the pressure shut down by closing the valve, and prevents removal of the cylinder before venting.

The invention may be put into practice in various ways but one embodiment of a valve and its coupling mechanism in accordance with the present invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a longitudinal view of a stand with a gas bottle in place in phantom lines with a valve and its coupling in accordance with the present invention; Figure 2 is a longitudinal view of only the valve and its coupling as shown in Fig. 1, similar to Fig. 1, but in section; Figure 3 is an enlarged view of the portion A of the valve shown in Figs. 1 and 2 in the closed position; Figure 4 is a view similar to that of Fig. 3 showing only part of the valve shown in Fig.

3 with the valve in the vent position; Figure 5 is a section along the line C-C of Fig. 2; and Figure 6 is a section at right angles to Figs.

2 and 5 showing the coupling mechanism.

Fig. 1 shows a mounting 1 for a gas bottle 2 including a valve and coupling mechanism 3. The bottle is held in place in the mounting 1 by a belt 4 around the circumference of the bottle whilst the neck 5 with its valve 6 are held in place by the coupling mechanism 7.

The valve 6 and coupling mechanism 7 are shown in more detail in Figs. 2 and 5.

Fig. 2 shows the valve and coupling in section. Figs. 3 and 4 show part of the valve in greater detail to show its operation. The valve itself operates by the extraction or retraction of a probe 8. Fig. 3 shows the probe extracted into the valve and the valve in the open position with an O-ring 9 compressed and held by a spring 10. Fig. 4 showing only the probe end has the probe partially retracted in the vent position so that gas can flow along the outside of the probe to a vent 1 3. When the probe is fully retracted out of the valve to close the valve (not shown) the O-ring 9 is uncompressed. Such a valve is described in our copending application published under No. 2103765A.

The valve may be operated manually or electrically and operation of the valve is via extraction or retraction of the probe 8 to open or close the valve. The valving unit is designed to open and close a valve by movement of a probe, such as an adaptor valve on a high pressure cylinder, and to provide a venting for residual pressure after closure of the valve.

When manually operated rotation of the wheel 1 2 moves the probe along the longitudinal axis (from side to side as shown by arrow P in Fig. 2) with the wheel handle directly attached to a screw threaded shaft or screw jack 14 via a spindle 1 6 (Figs. 2 and 5), which joins a shaft 1 7 (Fig. 5). The spindle is attached to a fairly coarse screw threaded shaft 14 of pitch 0.75. Over this screw threaded portion is a collar 1 5. Rotation of the wheel 1 2 screws the threaded portion 14 into or out of the collar 1 5 to extend or retract the probe 8. Full extension of the probe from full retraction is accomplished by three rotations of the wheel.A fixed cross piece 1 8 is located adjacent the threaded shaft 14 and is located within a cavity 1 9 within the valve body 20 with sufficient clearance between the cross piece and the walls of the cavity to allow free rotation of the cross piece. The travel of the cross piece on rotation of the wheel and thus the travel on the probe 8 is limited by the cavity 1 9. The limit of movement to the right is by the cavity wall 21. This can be most easily seen in Figs. 2 and 5.

Initial rotation of the wheel by one turn closes the vent 1 3 to atmosphere and continued rotation drives the probe into the adaptor valve releasing the pressure to the outlet port 11. Rotation of the wheel in the opposite direction initially withdraws the probe to close the adaptor valve and continued rotation vents the gas to atmosphere. A total of 3 turns are required to move the probe changing from a completely open valve to a completely closed valve.

Fig. 5 shows spindle 1 6 attached to a shaft 1 7 of slightly larger diameter than the spindle 1 6 and thus shaft 1 7 is attached to the screw threaded portion 14 and at this junction the cross piece is placed. As in the embodiment shown in Fig. 2 the limit of travel to the right is the cavity wall 21. This embodiment comprises a 28 volt DC motor which can be geared via a gear wheel 23 to operate extension or retraction of the probe. Such a motor will provide appropriate power for operation with a gear ratio of 1 8:1 and instead of three revolutions of the wheel for full travel of the probe it will need 54 revolutions of the motor.

A suitable small power requirement is thus demanded and a small battery may be used, for example a 28 volt DC motor. In this case the motor torque required to open the valve is approximately 40% of its maximum torque, (70z ins = 4.94 X 10-2Nm). Once the adaptor valve is completely opened or completely closed, the operating unit automatically shuts off. This may be achieved by arranging the power supply to the motor to provide a rise in current which automatically shuts off the unit, once the adaptor valve is completely opened or completely closed.

Movement of the probe 8 either via the manual rotation of the wheel 1 2 or via electrical operation from the motor 22 via the geared wheel 23 can be linked to a detent bar 24 which moves axially with the probe 8 and cross piece 1 8. The valve 6 may be attached to the gas cylinder 2 by a finger operated quick release mechanism 28. The detent bar 24 driven from the intermediate gear 23 engages and locks the release mechanism.

This prevents the entry of the adaptor valve when the probe is extended, prevents removal of the cylinder before withdrawal of the probe and pressure shut down and prevents removal of the cylinder before venting. As a further precaution a pressure operated detent could be added giving additional safety in the event of failure of the adaptor valve. However, for most purposes this situation of adaptor valve failure will be sufficiently well indicated by continued audible venting.

The quick release coupling mechanism is shown in more detail in Fig. 6. This comprises a two piece pince-nez arrangement with simple gearing. The two halves of the pince-nez 25,26 have pivot points 27. When the ends 28,29 of the halves 25,26 are pushed together the ends 30,31 of the halves 25,26 are held apart allowing the neck 5 of a gas bottle 2 to be held and clamped in place under the force of a spring which biases the ends 28,29 outward and thus the ends 30,31 inwards. To release the bottle the ends 28,29 are again pushed together overcoming the biasing force of the spring and levering the ends 30,31 outward. The coupling mechanism is prefereably operated by a quick action release latch as shown at 28 (Figs. 1 and 2) and also preferably engages with a stop or detent bar 24 as described above.

In this way the arms 25,26 can not be moved apart to accomodate the neck of the container and thus fasten the valve and its coupling mechanism to the container until the detent bar 24 is retracted. This can easily be accomplished by one or more protrusions 33 on the end 31 of arm 26 to abut the bar 24 or alternatively cooperate with a slot (not shown) in the bar 24. Once in position on the container a positive engagement may be effect by the valve and its coupling by means of stops 32 which can grip the neck of the container or cooperate with suitable grooves in the container.

Claims

1. A valve operating mechanism for movement of a probe to open or close the valve in which the probe is mounted to move on a threaded member.

2. A valve operating mechanism as claimed in Claim 1 in which movement of the probe is effected manually by rotation of a wheel to produce axial movement of the probe.

3. A valve operating mechanism as claimed in Claim 1 in which movement of the probe is effected electrically by a motor.

4. A valve operating mechanism as claimed in Claim 3 in which the motor is operated by a push button control.

5. A valve operating mechanism as claimed in any one of the preceding claims in which movement of the probe is via a geared wheel.

6. A valve operating mechanism as claimed in Claim 5 in which the gearing ratio is between 15:1 and 20:1.

7. A valve operating mechanism as claimed in any one of Claims 3 to 6 in which the motor is a 28 volt DC motor.

8. A valve operating mechanism comprising a detent bar to prevent operation of the valve under certain conditions.

9. A valve operating mechanism as claimed in Claim 8 in which the detent bar moves in association with movement of the probe.

1 0. A valve operating mechanism as claimed in Claim 9 preventing operation of the valve operating device whilst the probe is in the pressure release position.

11. A valve operating mechanism as claimed in Claim 8, 9 or 10 directly linked to gearing for operation of the probe.

1 2. A release arrangement for connecting a valve and its operating mechanism to a gas container comprising a scissor arrangement with a pivot between the ends, the arms of the scissor being biased inwardly at one end for connection to the gas container.

1 3. A release arrangement as claimed in Claim 1 2 in which the arms are biased inwardly directly or by biasing the opposite ends outwardly.

14. A release arrangement as claimed in Claim 1 2 or 1 3 in which the ends of the arms engaging the container have detents which engage cooperating slots in the gas container or an adaptor fitted on the gas container.

1 5. A release arrangement as claimed in Claim 12, 1 3 or 14 in connection with a valve operating mechanism as claimed in any one of Claims 1 to 7.

1 6. A release arrangement as claimed in Claim 12, 1 3 or 14 in connection with a valve operating mechanism as claimed in any one of Claims 8 to 11 in which the detent bar cooperates with the release arrangement preventing attachment of an operating mechanism whilst the detent bar is engaged or extended.

1 7. A release arrangement as claimed in Claim 1 6 in which one the release arrangement is attached it can not be released until the detent bar is itself disengaged or retracted.

1 8. A valve operating mechanism or a release arrangement or a combination thereof substantially as specifically described herein with reference to any one or any combination of one or more of the Figures of the accompanying drawings.