GB2115108A - Rotary valves - Google Patents

Abstract

A valve is provided with a tamper- proof operable part (18) rotation of which moves the valve member (14). The operable part (18) may be removed from a valve member driving spigot (19) and replaced thereon in a different position in which movement of the operable part (18) is prevented by abutment between pin (29) and a notch in the part (18). <IMAGE>

Description

SPECIFICATION Improvements in or relating to valves The present invention relates to valves for controlling fluid flow in pipes and is concerned with operable means either for automatic or manual operation to open, close or otherwise, changing the condition of a valve.

It is usual for valves whether manually or automatically operable to be operated through an operating member to which, usually, rotary motion is applied.

When the valve comprises a stop cock, the rotary movement of the operating member is conventionally clockwise to close the valve and anti-clockwise to open the valve.

Such rotary operation is usual even in valves in which the closure member itself does not undergo rotary movement to provide opening, closing or diverting means as the case may be, such as a gate valve for example.

It is desirable, for valves adapted to control certain fluids, for example gas, and other fluids which fluids present a potential hazard, to prevent unauthorised operation of the valve to prevent or minimise the possibility of the occurrence of accidents. For example, with gas valves having an operational member, the operating member may be adapted to be engaged by a key supplied to competant persons but not for general issue.

Unfortunately such a solution is not entirely satisfactory since in order to keep down the costs of valves, the operational member to which the key is supplied is of a simple shape, for example square in cross-section, the operating member being engageable by a key having a recess of similar square cross-section.

It will be apparent that such an operating member may be engaged by other means such as a spanner, a wrench or pliers and thus does not provide a satisfactory solution.

It is an object of the present invention to provide a new or improved valve means which provides a more satisfactory solution to the problems mentioned above.

According to one aspect of the present invention, we provide a valve means comprising an inlet, an outlet and a valve member movable between a first position in which said inlet and said outlet are in flow communication to a position in which flow communication is prevented, said valve having an operable part adapted for engagement to provide said movement, said operable part being securable to said valve member in a first position in which movement of said valve member by movement of said operable part is possible, and in a second position in which movement of said valve member is prevented.

Movement of the valve member may be prevented by preventing movement of the operable part itself, or alternatively allowing movement of said operable part but connecting the operable part to the valve member in a manner such that a drive between the two parts is not possible.

Preferably the operable part is detachably secured to the valve member and is adapted so that it may be secured to the valve member in two different positions, in one of which operation of the valve member by movement of the operable part is possible, and in the other of which movement of the operable part is not possible, thereby maintaining the valve member in a predetermined stationary position.

The means for preventing movement of the operable part may conveniently be obsccured by the operable part to prevent simple observation as to the reason for non-operation of the valve member.

The invention will now be described in more detail by way of example only, with reference to the accompanying drawings, wherein: Figure 1 is a side elevation partly in section of a valve incorporating the present invention; Figure 2 is a plan view of the valve shown in Figure 1; Figure 3 is a perspective view of the operable part and its connection to the valve member.

Referring to the drawings, a valve has a body generally indicated at 10 and ports 11 and 12 one of which may be inlet and the other an outlet.

Avalve member 13 comprises a substantially spherical part having a through bore 14 therethrough, the valve member 13 being mounted for rotation within the valve body 10 about an axis 16 and sealingly engaging the two ports 11 and 12 through annular seals 17 and 15 respectively.

The spherical valve member 13 is provided with an external operable part 18 rotation of which about the axis 16 causes movement of the valve member 13.

The valve member 13 is provided with an upwardly extending spigot 19 which is sealingly engaged by a seal 20 with the valve body, the spigot 19 having a rectangular like cross-section shown in dotted outline in Figure 3, and which engages in the corres pondinglyshaped recess in the operable part 18.

Such a cross-section on the spigot 14 may be formed by machining two diametrically opposed "flats" on the spigot which may originally be formed with a cicular cross-section.

The operable part 18 has an upper part 24 having a substantially square external cross-section and a central bore 20.

The square cross-section of the upper part 24 allows engagement of the operable part 18 by a key, having a square cross-section recess, to operate the valve to move the valve member 13 from a position in which the through bore 14 connects the two ports 11 and 12 to a position in which the ports 11 and 12 are cut off from each other.

The operable part 18 is secured by a threaded member 21 which abuts a shoulder 22 provided on the operable part, the threaded member 21 engaging in a complementary threaded through bore provided in the spigot 19. Since the recess in the operable part 18 and the spigot 19 having corresponding crosssections which closely fit with each other, a drive relationship between the spigot 19 and the operable part 18 is ensured.

The lower part 25 of the operable part 18 has a curved surface part 26 around part of its circumference, which curved part 26 is terminated at each end by shoulders 27 and 28. An upwardly extending pin 29 extends out of the substantially plain surface 30 of the valve body 10, which pin 29 is adapted to be abutted by the shoulders 27 and 28 to define predetermined set positions which may for example correspond to the valve being fully on and fully off respectively.

It will be appreciated that, depending on the number of ports provided on the valve, the porting arrangement provided in the valve member itself, the operable member may have any number of predetermined "set" positions defined for example by a detent arrangement between the operable part 18 and the valve body.

In the positions illustrated in the drawings, the operable part 18 may be moved quite freely between its limit positions defined by the shoulders 27 and 28 abutting the pin 29 to move the valve between its on and "off" positions and all positions inbetween.

The remainder of the external surface of the lower part 25 of the operable part 18 is of substantially square cross-section having two surfaces 32 and 33 substantially at right angles to each other, between which a notch 34 is provided. The notch 34 may be formed in the external surface as shown, or alternatively may be provided by a through bore or blind more extending upwardly from the lower surfaces of the operable part 181.

The valve has the valve member 13 shown in an on position, the through bore 14 extending between the ports 11 and 12, and itwill be noted thatthe notch 34 is angularly spaced from the pin by 90 .

If the operable part 18 is rotated through 90" so that the notch 34 is diametrically opposite the pin 29 then since the cross-section of the spigot 19 is of rectangular cross-section and the cross-section of the recess in the operable part 18 is of similar configuration, if the fastener 21 is removed and the operable part 18 disengaged from the spigot 19, it may be replaced on the spigot after having been rotated about the axis 14 through 1800. If it is placed on the spigot 19 after having been rotated through 1800, the notch 34 will partially surround the pin 29 and relative movement between the operable part 18 and the valve body 10 about the axis 14 will be prevented.The threaded fastener 21 may then be replaced and the operating member 18 and hence the valve member 13 is rendered inopeative with the valve member closing one port from the other.

It will be appreciated that in some valves it may be preferential to provide means for securing the valve member in an "on" position, an "off" position or possibly both, and relative interfering parts on the operating member and on the valve body may be so positioned to provide such alternatives.

The valve means of the present invention provides a very satisfactory method of preventing undesired interference with the positioning of the valve members while not completely preventing operation, for example in the cases of emerency.

It is envisaged that the threaded fastener 21 may be provided rather than with a longitudinal slot for engagement by a screw driver with a formation that may be engaged only by a particular form of key, and it is further envisaged that a cap or cover plate may be provided over the manually operable part 18 or at least in the recess formed in the upper surface thereof to obscure the head of the fastener 21.

Claims (14)

1. A valve means comprising an inlet, an outlet and a valve member movable between a first position in which said inlet and said outlet are in flow communication and a second position in which flow communication is prevented, said valve having an operable part settable in one of a plurality of different positions, in one of which positions movement of said valve member by movement of the operable part is possible and in another position in which movement of said valve member by the operable part is not possible.

2. A valve means as claimed in Claim 1 wherein movement of the valve member by the operable part is prevented by means preventing movement of the operable part itself.

3. A valve means as claimed in Claim 1 wherein movement of said valve member is not possible when said operable part is in said other position by discontinuation of driving engagement between said operable part and said valve member.

4. A valve means as claimed in any one of the preceding claims wherein said operable part is detachably secured to the valve member and is settable relative to the valve member in two different relative positions, in one of which positions operation of the valve member by movement of the operable part is possible, and in the other of which movement of the operable part is not possible.

5. A valve means as claimed in any one of the preceding claims wherein the means for preventing movement of the operable part is obscured by the operable part at least when said operable part is in its other position.

6. Avalve means as claimed in any one ofthe preceding claims wherein connecting means are provided connecting said valve member to said operable part, said operable part being releasably connected to said connecting means to permit of connection thereto in either one of two relatively different positions in one of which movement of said valve member by movement of said operable part is possible and in the other of which movement of said valve member by the operable part is not possible.

7. A valve means as claimed in Claim 6 wherein abutment means are provided adapted to abut said operable part when connected in said other position.

8. A valve means as claimed in Claim 6 or Claim 7 wherein said valve member is adapted for movement about a first axis, said operable part being mounted for movement about the same axis to move said valve member and being releasably connected to said valve member in a manner to permit of connection in two different positions angularly spaced about said axis.

9. A valve means as claimed in any of Claims 6 to 8 wherein said connecting means comprises a spigot-like member extending substantially along said axis and wherein said operable part is adapted to engage said spigot.

10. A valve means as claimed in any one of Claims 6 to 9 wherein the means for preventing movement of said operable part comprises abutting surfaces, one on said operable part and one on a valve body on which said valve member is mounted for movement.

11. Avalve means as claimed in Claim 10 wherein the means for preventing movement of said operable part comprises a protrusion provided on said valve body, which protrusion is engageable by said operable part when in said other position.

12. Avalve means as claimed in Claim 11 wherein said protrusion comprises a pin-like member extending from said valve body and which is engageable within a recess in said operable part when said operable part is in said other position.

13. A valve means substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

14. Avalve means including any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawings.