GB2166221A

GB2166221A - Improvements in or relating to disc valves and to structures incorporating such valves

Info

Publication number: GB2166221A
Application number: GB08424903A
Authority: GB
Inventors: Hugh Vernon Barnes
Original assignee: TI GAS SPARES Ltd
Current assignee: TI GAS SPARES Ltd
Priority date: 1984-10-03
Filing date: 1984-10-03
Publication date: 1986-04-30
Also published as: GB8424903D0

Abstract

A valve suitable for controlling gas flow, especially to the burner of a gas-fired appliance, is of the so-called "disc" type in which the flow control member (10) has an operative face which rotates over a plane surface in the valve housing (2) to control gas flow through an opening (5) in that surface. The valve can be mounted on a gas rail (1) to control flow from the rail, in which case the rail may form part of the valve housing (Figure 7) and, in particular, that part providing the plane surface in which the opening (5) is formed. A sealing member (9) is located between the plane surface and the operative face of the flow control member (10). The valve has a spindle (16) which can be releasably-coupled to the control member (10) to rotate the latter. <IMAGE>

Description

SPECIFICATION Improvements in or relating to disc valves and to structures incorporating such valves This invention relates to disc valves especially disc valves for controlling the flow of gases, for example gaseous fuels, and to structures incorporating such valves.

Appliances fired by gaseous fuels have, for many years, incorporated control valves for controlling the flow of the fuel to fuel burners. Many of such valves comprise a frusto-conical plug rotatable in a mating housing. Radial ports in both plug and housing coact to control gas flow. This construction is both expensive to manufacture and to assemble.

Disc valves are a possible alternative to the conventional valve as just described but are not widely used because, heretofore, they have been of a complex and hence expensive construction. Such disc valves employ a lapped disc rotating over a co-operating lapped surface to uncover and cover ports in the latter and thereby control flow through the valve.

In both plug valves and disc valves as described above, careful machining is necessary to ensure mating surfaces that are gas tight.

According to the present invention, a fluid flow control valve comprises a housing having first and second openings at least one of which is located in a plane surface of the housing, a rotatable control member with an operative face lying in a plane parallel to the plane surface, and a sealing member located between the plane surface and the operative face, the arrangement being such that fluid flow from one opening to the other is controllable by rotation of the control member.

The sealing member may be a resilient sealing member.

Resilient means may be provided for resiliently urging the control member towards the plane surface.

The sealing member may be of annular form.

The sealing member may be disposed around the openings located in the plane surface.

The sealing member may be eccentrically disposed with respect to the axis of rotation of the control member.

In one embodiment of the invention, the control member includes a drive member through which rotation is imparted to the control member, and in which the valve further includes a drive spindle rotatable about the axis of rotation of the control member and means for coupling the drive spindle to the disc.

The control member may have a tubular extension disposed coaxially with the axis of rotation of the sealing disc.

The tubular extension may be in telescopic engagement with the drive spindle.

The tubular extension of the control member may have a bore which accommodates the resilient means, the bore being located upon a longitudinal axis substantially coaxial with the axis of the sealing member.

The resilient means may be a helical spring.

The drive spindle may carry a drive plate, and the control member a drive stud, the latter being engageable by the drive plate in such manner that rotation of the spindle is transferred to the disc.

The plate may have driving prongs for engagement with the drive stud.

Preferably, the valve includes a niting arrangement which may comprise a niting surface on the drive plate and a co-operating niting cam on the housing. The surface may be that of a projection on the drive plate.

The cam may be located on a cover of the housing.

The spindle may carry movement indexing means, and in which the housing supports a surface that co-operates with the indexing means.

The co-operating surface may be adjustable in position in a manner such as to change the rate of flow of fluid from the inlet to the outlet for a particular angular position of the spindle.

The co-operating surface may be that of a projection extending axially from a collar rotatably mounted upon the housing.

Part of the housing may be constituted by a gas supply conduit which may be a gas rail.

One of the openings may be formed in the gas rail, the surface of the latter in the vicinity of the opening being adapted to accommodate the sealing member.

The gas rail may also include another opening that communicates with the interior of the housing.

Part of the control member may be cutaway in such manner as to allow, in selected angular positions of the control member, flow of fluid from one opening to the other at a rate dependent upon the area of the cutaway that lies within the sealing member.

Alternatively, or additionally, the control member may have a series of differently sized apertures, and in which rotation of the control member brings the apertures in sequences into the confines of the sealing member, the arrangement being such that the rate of fluid flow from the one opening to the other is determined by the areas of those apertures lying within the confines.

The operative face of the control member facing the annular sealing member may have a V-shaped groove in communication at one end with the cutaway and of transverse cross sectional area that decreases with increasing distance from the cutaway and so orientated that the rate of flow from an opening to the other is initially determined by the extent to which the groove extends into the confines of the sealing member.

The edges of the cutaway, apertures and groove respectively are contoured in such manner as to avoid damage to the sealing member.

By way of example only, embodiments of the invention will now be described in greater detail with reference to the accompanying drawings of which Figure l is a vertical section of a first embodiment, Figure 2 is a scrap view of part of the first embodiment, Figure 3 is a plan view of the first embodiment, Figure 4 is a plan view of part of the first embodiment with certain components removed, Figure 5 is an exploded perspective view of the first embodiment, Figure 6 is a perspective view of the first embodiment, Figure 7 is a vertical section of a second embodiment, Figures 8, 9 and 10 are, respectively, vertical section, view from one end, and side view of a third embodiment, and Figures 11, 12 and 13 are, respectively, vertical section, view from above and side view of a fourth embodiment.

The first embodiment is a valve for controlling the flow of gaseous fuel to a gas burner from a conduit which is shown in Figure 1 as a gas rail 1 but which could be merely a supply conduit.

The valve has a casing 2 of generally cup shaped form with integral extensions 3, 4 whose purpose will be described below. The casing 2 has an inlet 5 in its bottom wall and an outlet 6 that extends radially from the casing 2 between the extensions 3, 4. The inlet 5 is eccentrically disposed with respect to the axis 7 of the valve.

The face of the bottom wall of the casing is also formed with an annular groove 8 that is concentric with the inlet 5. Located in the groove 8 is a resilient sealing element 9 for example an annular '0' ring seal.

Seated upon the annular seal 9 is a disc 10 having a central, upward, tubular extension 11. Part of the disc 10 is cutaway as shown at 12 in Figures 4 and 5 and in a position opposite to the cutaway 12 is an upstanding drive stud 13.

Leading away from the cutaway 12 and formed in the lower face of the disc 10 is a groove 14 of triangular transverse cross-section that decreases in size with increasing distance from the cutaway.

The lower edges of the cutaway 12 and of the groove 14 are smoothly rounded.

The bore 15 of the tubular extension 11 is closed at its inner end and is orientated eccentrically with respect to the longitudinal axis 7 of the valve.

The extension 11 engages telescopically inside the bore of a spindle 16 at whose lower end (as seen in Figure 1) is secured a drive plate 17 of generally circular form. Housed in the bore 15 and compressed between the lower end of the latter bore and the upper end of the bore of the spindle 16 is a helical spring 18. When the valve is assembled, spring 18 urges the disc 10 into gas-tight contact with the seal 9, a more balanced pressure on the latter being obtained as a result of the eccentric positioning of the bore 15 referred to above.

Drive plate 17 has spaced driving prongs 19 (Figure 5) and, in a diametrically opposed location, a radially extending finger 20. The space between the prongs 19 is aligned with the drive stud 13 which fits between them. Although shown as downwardly-inclined in Figures 1 and 5, the prongs 19 could be co-planar with the remainder of the drive plate 17. A slightly longer drive stud may then be required.

About midway of its length, the spindle 16 has a peripheral groove 21 in which is located an '0' ring seal 22.

The open end of the cup-shaped housing 2 is closed by a top cover 23 having a central tubular extension 24 through which the spindle 16 projects as shown in Figure 11. The projecting end of the spindle 16 has a 'flat' 25 to enable the spindle 16 to be operated by a control knob (not shown). The top cover 23 seats on an internal ledge of the housing 1, on which is also seated a leak-preventing washer. The cover is secured in place by distorting the upper edge of the housing 2 as indicated at 26. The top cover 23 has a locating spur 27 which fits into a mating recess 28 formed in the upper edge of the housing 2.

The lower (as seen in Figure 5) face of the cover 23 is formed with one part of a niting mechanism comprising a cam in the form of an annular rib 29 having a gap 30 that defines the OFF position of the tap and a stop 31 that defines the full 'ON' position. The rib 29 co-operates with the finger 20 on the drive plate 17 to provide the niting mechanisms for the tap.

The outer upper face (as seen in Figure 1) of the cover 23 has a mounting block 33 for a ring 34 which fits over the projecting end of the spindle 16. The ring has a curved slot 35 through which passes a screw 36 by which the ring 34 is secured to the mounting block. The underneath surface of the ring 34 is cutaway as at 37 to form a sharplysloped cam face 38 leading to a plateau 39 between end faces 40. The plateau 38 is broken by a shallow radial groove 41.

Extending radially from the spindle 16 at a position along the length of the latter enabling it to cooperate with the cam face 38, is a peg 42. When the valve is in its 'OFF' position with the finger 20 located in the gap 30, peg 42 is positioned as shown in Figure 2 at the commencement of the cam face 38.

To operate the tap, a user first depresses spindle 16 inwardly to allow finger 20 to disengage slot 30 and peg 42 to align with plateau 39. The user now rotates the spindle 16 and this rotation is transferred to disc 10 and because the latter is positioned eccentrically with respect to the inlet 5, cutaway 12 and groove 13 gradually approach the inlet. As soon as the tip of the groove 13 crosses the seal 9, communication at a minimum level is established from inlet 5 to outlet 6 via the groove.

Further rotation of the spindle increases the level of communication and the highest rate is achieved when the cutaway 12 has crossed the seal 9 by an amount that brings finger 27 into contact with stop 31 at which point the tap is fully 'ON'.

As the peg 42 travels along the surface of the plateau 39 it encounters the groove 41 and the user can feel a slight axial movement of the spindle 16. That movement defines the "simmer" position of the valve. Because of the way in which the ring 34 is secured in place via the screw 36 and the slot 35, it is possible to vary the effective position of the groove 41 and thus flow at the 'simmer' position to suit different gaseous fuels with which the tap may be used. By loosening the screw 36, a degree of rotation of the ring 34 is possible within the limits imposed by the arcuate length of the slot 35 and in this way the position of the groove 41 is adjustable.

Should the user attempt to reduce flow much below the 'simmer' rate, peg 42 encounters the face 38 and because of the rather sharp slope of the latter, the spindle 16 is urged by the spring 16 to rotate into the "OFF" position of the valve with a slight "snap" action. This provides a safety feature preventing the user setting the tap to a position at which flow is so low that a stable flame cannot be assured.

It will be appreciated that the "snap"-OFF feature just described is not essential and there may be circumstances in which the tap could be used without it.

As shown in Figure 1, the tap is mounted upon a gas rail 1 and controls the rate of flow of gas from a bore 43 in the rail to the outlet 6 and via an injector secured to the latter to a gas burner (not shown). The tap is mounted on the rail 1 by means of a bracket 44 that extends round the lower surface of the rail and has outward flanges 45 to which the tap is secured by means of bolts 46. A leak preventing gasket is interposed between the base of the tap and the upper surface of the rail as can be seen in Figure 1.

If used with an alternative form of gas rail having integral laterally extending flanges, the tap may be secured in position on the rail by means of bolts 46 that pass through the flanges.

In the embodiment shown in Figure 7, the tap is mounted upon a gas rail, part of which forms a closure for the valve housing. In addition, the annular seal is contained in a circular groove in the surface of the rail.

In Figure 7, parts of the tap that correspond with similar parts of the tap just described with reference to Figures 1-6 have the same reference numbers.

In the embodiment of Figure 7, a gas rail 47 with a longitudinal bore 48 has a plain upper surface machined at spaced intervals along the length of the rail to provide annular grooves each located concentrically with the upper end of passageways leading to the bore 48. One of such grooves and passageways is shown in Figure 7 and referenced 49 and 50 respectively.

The gas rail 47 also has a series of lateral outlet passages formed in it which communicate with short passages each of which lies adjacent a different one of the passageways 50. Figure 7 shows one such lateral passage 51 and communicating passage 52. Each passage 51 is adapted to receive an injector.

The gas tap has an inverted cup-shaped housing 53 with a central tubular, upward extension 54. The housing 53 is seated upon the upper surface of the gas rail as shown in Figure 7 and secured to the rail in a manner not shown. Leakage of gas between the edge of the housing and the surface of the rail is prevented by a gasket 55.

Rotatably mounted in the extension 54 is the spindle 16 of the tap, the spindle carrying the drive plate 17 at its lower end. Telescopically engaged in the bore of the spindle 16 is the extension 11 of the disc 10, the construction of which is identical with that of the disc described above.

Omitted from Figure 7 is the collar 34 and peg 42.

The tap shown in Figure 7 operates in a manner similar to that of the tap shown in Figure 1 to control flow of gas from the bore 48 to the lateral outlet passage 51 and so to a gas burner.

The positions of the inlet and outlet to the valve housing can be reversed and the tap can be configured to operate in other orientations than with the spindle 16 vertical.

Figures 8-10 show another embodiment in which flow through the tap is reversed as compared with that through the valves described above and in which the spindle of the tap is horizontal.

The tap shown in Figures 8-10 has a cup shaped housing 56 formed with a flat base 57 by means of which the tap may be mounted upon a gas rail or other gas supply conduit.

The wall of the housing has an inlet 58 while the base has an outlet 59. Around the outlet 59, the base of the housing has an annular groove in which is located an annular sealing member 60.

Flow of gas from inlet 58 to outlet 59 is controlled by a disc 10 whose construction is similar to that of the disc valves described above with reference to Figures 1 and 7. The disc 10 of the embodiment shown in Figures 8-10 is driven in a similar manner to the discs of the Figures 1 and 7 embodiments.

The tap will also incorporate a niting mechanism part only of which is shown in Figure 8, the drive plate 17 having a finger 18.

The housing 57 has a cover 61 of generally frusto-conical form through which the drive spindle 16 extends. Surrounding the cover 61 is collar 62 with a lateral extension 63 slotted as at 64.

Through the slot passes a screw 65 by means of which the collar 62 is secured to the housing 57.

The collar 62 has a projection 66 on each side of which the collar 62 is deeply slotted as indicated at 67. The inner face of the projection 66 has a small axial recess 68 whose floor is rounded as shown in Figure 9.

Secured diametrically to the spindle 16 at an axial position aligned more or less with the free end of the projection 66 is a pin 69 part of whose length extends outwardly from the spindle.

The embodiment shown in Figures 8, 9 and 10 operates in much the same manner as the embodiment described above with reference to Figures 16. A user first depresses the spindle 16 inwardly to disengage the finger 16 from the slot in the co-operating portion of the niting arrangement after which the spindle is rotated to bring the disc valve 10 into a position giving a desired rate of flow of gaseous fuel from inlet 58 to outlet 59. As the spindle 16 is rotated, the head of the pin eventually passes over the inner face of the projection 66. As it passes over the inner face of the projection, the pin deflects the projection 66 outwardly slightly, the slots 67 ensuring a sufficient degree of resiliency of the projection 66 to enable it to deflect.

As the end of the pin 69 enters the recess 68, the user feels a slight relaxation of the resistance to rotation.

The recess 68 is used to indicate a specific angular position of the spindle 16 corresponding to, for example, a simmer position. By loosening the screw 65, it is possible to rotate the collar 62 within limits set by the arcuate length of the slot 64 and this enables the angular position of the recess 68 to be adjusted slightly to select different gaseous fuels.

The "snap-off" feature is particularly useful in cases in which the tap incorporating it controls flow of gaseous fuel to a burner of the surface combustor type. Such a burner is sometimes used as a grill burner. Combustion of fuel in surface combustor burners becomes inefficient at a very low rate of fuel flow and it is desirable that the burner should not be allowed to operate at such low rates of fuel flow.

This snap-on feature is particularly suitable for use in a grill burner gas control tap an example of which is shown in Figures 11-13. The tap is generally similar to that described above with reference to Figures 1-6 and similar parts have the same reference numbers as in those latter Figures.

The tap has a cup-shaped housing 2 as before, flow from inlet 5 to outlet 6 being controlled by a disc 10 contoured as described above. The housing is closed by a cover 23 with a tubular extension 24 which accommodates the lower part of a drive member 70 having a bore into which extends the extension 11 of the drive disc 10. The upper part of the drive member 70 extends beyond the extension 24 and has an upper bore in which the lower portion of a drive spindle 71 is telescopically received.

The upper portion of the drive spindle is formed with a flat 73. Towards its lower end, the spindle carries a radially-extending peg 73 which forms one element of a niting arrangement for the tap.

The peg 73 passes through a longitudinal slot 74 in the drive member 70. Associated with the peg 73 to form another element of the niting arrangement is a sleeve 75 located externally of the tubular extension 24 of the tap cover 23 to which it is secured by means of a screw 76 that passes through a projecting fab 77 on the sleeve 75 into a boss 78 that is part of the cover 23.

The curved wall of the sleeve has a slot 79, the upper edge of which is formed to provide the other part of the niting arrangement. That edge has a sharply inclined portion 80 leading to a plateau 81 broken by a shallow radial groove 82 adjacent the portion 80.

The tap shown in Figures 12 and 13 operates in a manner similar to that of the taps described above. A user first depresses the spindle 71 inwardly against the combined action of spring 18 aided by a further somewhat stronger spring 83.

This inward movement of the spindle 71 brings peg 73 level with the plateau 81 and moves the prongs on the drive plate 17 with drive stud 13 on the disc 10.

The spindle 71 is now rotated to allow the user to adjust the rate of flow of gas through the tap.

Radial groove 82 identifies the minimum allowable rate of gas flow to the burner. Any attempt by the user to reduce the gas flow below that minimum rate brings the peg 73 on to the portion 80 and allows the combined action of the springs 18 and 83 to raise and rotate the spindle 71 to bring the disc 10 into its 'OFF' position so terminating gas flow to the burner.

It will be appreciated that the problems of accurate machining to produce accurate mating surfaces is avoided in the constructions described above by the use of the resilient annular seals. In addition, the simplified design of the taps described above reduces manufacturing and assembly costs as compared with the prior art disc valves or taps.

It will be appreciated that it is not essential to locate the sealing element in a groove surrounding the inlet or outlet. The element may be located upon the undersurface of the disc in a suitable groove. In that case, however, the element may not be of annular form but of a form determined by, inter alia, the relative positions of the valve inlet and outlets.

For example, if both inlet and outlet are located in the base of the valve housing and the under-surface of the disc provided with a channel able, in particular angular positions of the disc, to place inlet and outlet in communication, the sealing member would be located round the periphery of the channel and be shaped to conform to the peripheral shape.

Again, with a valve housing an outlet in the curved wall of the housing, the rotary disc may be of the form described in the preceding paragraph.

Access to the outlet may be provided by a channel in the base of the valve housing.

Claims

1. A fluid flow control valve comprising a housing having first and second openings at least one of which is located in a plane surface of the housing, a rotatable control member with an operative face lying in a plane parallel to the plane surface, and a sealing member located between the plane surface and the operative face, the arrangement being such that fluid flow from one opening to the other is controllable by rotation of the control member.

2. A valve as claimed in claim 1 in which the sealing member is a resilient sealing element.

3. A valve as claimed in claim 2 in which resilient means are provided for resiliently urging the control member towards the plane surface.

4. A valve as claimed in any one of claims 1-3 in which the sealing member is of annular form.

5. A valve member as claimed in claim 4 in which the sealing member is disposed around the opening located in the plane surface.

6. A valve as claimed in any one of the preceding claims in which the annular sealing member is eccentrically disposed with respect to the axis of rotation of the control member.

7. A valve as claimed in any one of the preceding claims in which the control member includes a drive member through which rotation is imparted to the disc, and in which the valve further includes a drive spindle rotatable about the axis of rotation of the control member and means for releasably coupling the drive spindle to the control member.

8. A valve as claimed in claim 7 in which the control member has a tubular extension disposed coaxially with the axis of rotation of the control member.

9. A valve as claimed in claim 8 in which the tubular extension is in telescopic engagement with the drive spindle.

10. A valve as claimed in claim 8 or 9 and in which the tubular extension has a bore which accommodates the resilient means, the bore being eccentrically disposed with respect to the axis of the drive spindle.

10. A valve as claimed in claim 8 or 9 and in which the tubular extension has a bore which accommodates the resilient means, the bore being located upon a longitudinal axis substantially coaxial with the axis of the sealing member.

11. A valve as claimed in claim 9 or 10 in which the resilient means comprises a helical spring.

12. A valve as claimed in any one of claims 811 in which the drive spindle carries a drive plate, and the control member a drive stud, the latter being engageable by the drive plate in such manner that rotation of the spindle is transferred to the control member.

13. A valve as claimed in claim 12 in which the plate may have driving prongs for engagement with the drive stud.

14. A valve as claimed in any one of the preceding claims and further comprising a niting arrangement.

15. A valve as claimed in claim 14 when appended to claim 12 or 13 in which the niting arrangement comprises a niting surface on the drive plate and a co-operating niting cam on the housing.

16. A valve as claimed in claim 15 in which the housing has a cover through which the drive spindle extends and which carries the niting cam.

17. A valve as claimed in claim 14 when appended to any one of claims 7-16 in which the spindle carries movement indexing means, and in which the housing supports a surface that co-operates with the indexing means to define one of the rotary positions of the spindle.

18. A valve as claimed in claim 17 in which the co-operating surface is adjustable in position in a manner such as to vary the rate of flow of fluid from one opening to the other for a particular angular position of the spindle.

19. A valve as claimed in claim 17 or 18 in which the co-operating surface is that of a projection extending axially from a collar rotatably mounted upon the housing.

20. A valve as claimed in any one of the preceding claims in which part of the housing is constituted by a gas supply conduit.

21. A valve as claimed in claim 20 in which the gas supply conduit is a gas rail.

22. A valve as claimed in claim 20 in which the outlet is formed in the gas rail, the surface of the latter in the vicinity of the outlet being adapted to accommodate the sealing member.

23. A valve as claimed in claim 22 in which the gas rail includes an outlet that communicates with the interior of the housing.

24. A valve as claimed in any one of the preceding claims in which part of the control member is cutaway in such manner as to allow, in selected angular positions of the control member flow of fluid from one opening to the other at a rate dependent upon the area of the cutaway that lies within the sealing member.

25. A valve as claimed in any one of claims 123 in which the control member has a series of differently sized apertures, and in which rotation of the control member brings the apertures in sequences into the confines of the sealing member, the arrangement being such that the rate of fluid flow from one opening to the other is determined by the areas of those apertures lying within the confines.

26. A valve as claimed in claim 24 in which that operative face of the control member has a Vshaped groove in communication at one end with the cutaway and of transverse cross sectional area that decreases with increasing distance from the cutaway and so orientated that the rate of flow from one opening to the other is initially determined by the extent to which the groove extends into the confines of the sealing member.

27. A valve as claimed in any one of claims 2426 in which the edges of the cutaway, apertures and groove respectively are contoured in such manner as to avoid damage to the annular sealing member.

28. A valve substantially as herein described with reference to and as illustrated by Figures 1-6, or Figure 7 or Figures 8-10 or Figures 11-13 of the accompanying drawings.

Amendments to claims have been filed, and have the following effect: (a) Claims 1, 7, 10 above have been textually amended.

(b) Textually amended claims have been filed as follows:

1. A fluid flow control valve comprising a housing having first and second openings at least one of which is located in a plane surface of the housing; a rotatable control member with an operative face lying in a plane parallel to the plane surface, and a sealing member located between the plane surface and the operative face, whereby fluid flow from one opening to the other is controllable by rotation of the control member, the valve further including a drive member through which rotation is imparted to the control member and means for releasably coupling the drive member to the control member.

7. A valve as claimed in any one of the preceding claims, in which the drive member includes a drive spindle longitudinal movement of which con trols the releasable coupling of the drive member to the control member.