GB2126691A - Closure valve - Google Patents

Abstract

A water tap includes a main valve member 20, cooperating with a valve seat 22, the member 20 being in the form of a piston working in a dash-pot cylinder 18, the valve member 20 being movable, via a spindle 36, with lost motion. When the spindle 36 is depressed, via an operating knob, 80, the subsidiary valve member 60 is moved downwardly to its open position and the valve member 20 is moved downwardly into cylinder 18, while water from the cylinder 18 flows past the subsidiary valve, out of the tap. When the operating knob is released, the subsidiary valve member is drawn up into its closed position, and in turn draws the member 20 upwardly, so that the sole communication with cylinder 18 is provided through a restricted bleed passage 94, and thus the cylinder 18 fills only slowly so that the valve member 20 moves only slowly into engagement with its valve seat 22 after a predetermined period. The period for which the valve remains open can be adjusted by adjusting the operating stroke of the valve by an adjustment member 70, or by altering the effective size of the bleed passage 94 by inserting therein an end part of a "C" shaped clip of wire of appropriate diameter. <IMAGE>

Description

SPECIFICATION Closure valve This invention relates to a closure valve, for example for a water tap, of the kind adapted to close automatically after a predetermined period reckoned from termination of an opening operation of the valve.

More particularly, the present invention relates to a valve of the kind referred to which is so contrived as to close in a gradual manner so as to be non-concussive, i.e. so as to avoid "hammering" in a water supply system to which the valve is fitted and to give a water delivery for a predetermined period before self-closing.

Taps equipped with such valves are commonly used in wash-rooms in public places, hospital wash-rooms and the like, being primarily designed to avoid undue wastage of water.

It is an object of the present invention to provide an improved valve of the kind referred to.

According to the present invention there is provided a closure valve including a main valve member reciprocable, via an actuating member, towards and away from a co-operating valve seat, and a dash-pot cylinder in which works a piston formed by or connected with the main valve member, said actuating member being arranged for operation of a subsidiary valve seat around a first passage communicating with said dash-pot cylinder, said dash-pot cylinder having a restricted bleed passage communicating therewith and biasing means being provided biasing said actuating member in the direction to move the main and subsidiary valve members towards their respective closed positions, the actuating member being capable of limited lost motion relative to the main valve member, the arrangement being such that, with the valve in a closed condition, an initial movement of the actuating member in a direction to move the main valve member away from its valve seat displaces the subsidiary valve member away from its valve seat before causing movement of the main valve member and piston, so that the dash-pot chamber is readily changed in volume with the fluid thereby displaced passing through said first passage, and the arrangement further being such that when the actuating member is thereafter released, said biasing means first displaces the actuating member relative to the main valve member and piston to engage the subsidiary valve member with its valve seat to close said first passage, before causing movement of the main valve member towards its valve seat, so that, due to the throttling effect of said restricted bleed passage on the fluid which must pass therethrough to allow the corresponding movement of said piston in the dash-pot cylinder, engagement of the main valve member with its valve seat occurs only after a delay.

In the preferred embodiment, the volume of the working chamber of the dash-pot cylinder is increased during such movement of the main valve member towards its valve seat, so that fluid is drawn into the dash-pot cylinder through said restricted bleed passage during such movement of the main valve member towards its valve seat.

However, it would, of course, be possible, alternatively, to construct the valve so that fluid was displaced from the dash-pot cylinder through said restricted bleed passage during such movement of the main valve member towards its valve seat.

An embodiment of the invention is described below by way of example, with reference to the accompanying drawings, in which: FIGURE 1 is an axial section view of a water tap incorporating a valve embodying the invention; FIGURE 2 is a plan view of a circlip forming part of the valve of Figure 1; and FIGURE 3 is an axial section view, similar to Figure 1, of a variant tap.

Referring to the drawings, a tap to supply a wash-hand-basin, comprises a body 10 having a fixing flange 12 adapted to engage a supporting surface, the body 10 having an inlet spigot 14 for connection to a supply of water under pressure and a delivery spout 1 6. The inlet spigot 14 extends along a vertical central axis of the body, while the delivery spout 1 6 extends transversely relative to the said vertical axis.

The body 10 defines internally a dash-pot cylinder 1 8 having said vertical axis as its central axis, the lower end of which cylinder, defined by a lower end wall of the housing 10, is closed.

Mounted for vertical reciprocating movement in the cylinder 1 8 is a member 20 which affords, in combination, a piston working in the cylinder 1 8 and a valve member which, in co-operation with a valve seat 22 afforded by a head member 24 screwed into the upper end of the body 10 controls, and, in the closed position of the valve serves to cut off, the supply of fluid from the inlet spigot 14 to the delivery spout 1 6.

The head member 24 is substantially annular in cross-section and co-axial with cylinder 18. The valve seat 22 is provided by an annular rib 22 formed at the lower end of the head member 24, adapted to co-operate with a seating washer 26 carried in an annular groove formed in the upper end of the member 20. The head member 24 is sealed with respect to the body member 10 by means of a "0"-ring 28 received in a circumferential groove formed around the member 24 adjacent its lower end and engaging the internal wall of the body 10. An axial water passage 30 extends into the head member 24 from the lower end thereof, the entrance to said bore being bounded by the valve seat 22. Bore 30 is stepped down to a smaller axial bore 34 which passes upwardly through head member 24 and in which an actuating spindle 36 is mounted as a close sliding fit, and sealed with "0" rings 50.

Radial passages 40 connect the water passage 30 with a circumferential groove 41 formed around the head 24 at a position just above "O"-ring 28 and forming an exit water-way. The spigot 14 has an internal passage which communicates, via a water-way which skirts the dash-pot cylinder, with the central bore of the body 10 in a port 44 positioned below the "O"-ring 28, whilst the delivery spout 16 has an internal passage which communicates with the main bore of the body 10 in a port 46 which is in register with the groove 41.

The actuating spindle 36 has a smooth cylindrical section extending through the bore 34 and formed with circumferential grooves in which the "O"-rings 50 are located, the spindle 36 extending through the bore 30 and carrying, at the lower end of said plain cylindrical section, an enlarged hexagonal boss 52 which is received in a bore 54 extending from the upper end of the member 20 within a central projection which is bounded by the annular groove receiving the seating washer 26. Extending from the lower end of the hexagonal boss 52 is a further, co-axial, cylindrical part 56 of reduced diameter with respect to the part extending through passage 34, said part 56 extending with clearance through a central aperture formed through the member 20 and into a recess defined by a bore 58 extending axially into the member 20 from the lower end thereof.The lower end of the portion 56 is screwed to engage with a subsidiary valve member 60 carrying at its upper end a seating washer 62 encircling the spindle portion 56 and adapted to co-operate with a downwardly facing annular valve seat 64 provided by the member 20 at the upper end of the recess afforded by the bore 58. It will be appreciated that the last-noted recess is in communication, via the lower end of the bore 58, with the chamber defined within the dash-pot cylinder 1 8 between the member 20 and the lower end of the cylinder 1 8.

At its upper end, the spindle 36 is screwthreadedly engaged in an internally screwthreaded axial bore formed in a sleeve 70, the lower end of which is received within an axial counter-bore 72 extending from the upper end of the head member 24 and terminating at its lower end in an annular abutment shoulder 74. At its upper end the sleeve 70 has a radially outwardly extending flange 76 and a compression spring 78 acts between the head member 24 and the flange 76 to urge the sleeve 70, and thus the spindle 36, upwardly. The spring 78 is located at its upper and lower ends in respective seats formed around the spindle 76 and member 24.The upper end of the sleeve 70 is covered by a cap-like operating knob 80, having a peripheral cylindrical wall 82 extending slidably through an aperture provided at the upper end of a cap 84 which is screwthreadedly engaged on an externally threaded flange 83 provided on the head member 24. A radially outwardly extended flange at the lower end of the wall 82 co-operates with a radially inwardly extending flange of the cap 84.

(The inner edge of the last-mentioned flange defines the aperture in the cap 84 through which extends the knob 80). These co-operating flanges retain the knob 80 captive and limit its upward movement relative to the cap 84 and the remainder of the valve. Within the cap 84 a further compression spring 90 acts between the head member 24 and the lower end of the operating knob 80 to urge the latter upwardly, independently of the position of sleeve 70. It will be appreciated that the upper end of the member 24, the sleeve 70 and the springs 78 and 90 are all enclosed within the cap 84 and operating knob 80.

Adjacent the lower end of the member 20, the latter is fitted with an annular cup washer E, affording the piston seal, retained by a nut 92 screwed onto the lower end of the member 20.

The space within the bore 58 communicates, via a small radial bleed 94 adjacent the upper end of the bore 58, with an annular groove 96 formed around the member 20 above the cup washer E.

In the closed position of the valve as shown in Figure 1, the spring 78 urges the spindle 36 upwardly to urge the valve member 60 upwardly against the valve seat 64 and thus to urge the member 20 upwardly to engage the seal 26 with the valve seat 22, thereby preventing the passage of fluid from the passage within the spigot 14 to the delivery spout 1 6. It should be noted that the length of the spindle portion 56 is such that in the closed position of the valve the lower end of the hexagonal boss 52 is spaced upwardly somewhat from the lower end of the bore 54, so that the spindle 36, with the valve member 60, is capable of limited lost motion with respect to the member 20, between the position shown in Figure 1 and a position in which the lower end of the hexagonal boss 52 engages the lower end of the bore 54.

The lower end of the bore 54 is formed with a frusto-conical countersink, so that the lower end face of the boss 52 does not form a seal with the lower end of the bore 54 when engaged therewith but defines, with the lower end of the bore, six segmented openings to the region of the countersink. Furthermore the spindle portion 56 extends with substantial radial clearance through the central aperture in the member 20 and the hexagonal form of the boss 52, in co-operation with the cylindrical bore 54 affords passages for fluid between the boss 52 and the wall of the bore 54.As a result, when, starting from the closed position of the valve shown in Figure 1, the knob 80, and thus the sleeve 70, is depressed, so that the spindle 36 and thus the boss 52 and valve member 60 are moved downwardly relative to the member 20 until the lower end of the hexagonal boss 52 engages the lower end of the bore 54, the sealing washer 62 is displaced downwardly away from the seat 64 and a passage for the flow of fluid is established from the chamber of the dashpot cylinder 18, between the bore 58 and valve member 60, past the valve seat 64, around the cylindrical portion 56 and between the boss 52 and bore 54 to the water passage 30 and thus to the delivery spout. During continued downward movement of the spindle 36 and cap 80 against the biasing force of the springs 78 and 90, water is displaced from the dash-pot chamber through the last mentioned passage by the downward movement of the member 20, the downward displacement of the member 20 away from the valve seat 22 allowing water to pass from the inlet spigot to the delivery spout.

When downward pressure on the cap 80 is released, the cap 80 is returned immediately by the spring 90 to its former position. However, the spindle 36 and sleeve 70 are initially moved upwardly by the spring 78 only so far as to engage the washer 62 with the valve seat 64 so that the only path of fluid communication between the chamber of the dashpot cylinder and the inlet and outlet of the valve is via the bore 58, through the restricted bleed passage 94, the annular groove 96 and the clearance between the wall of the cylinder 18 and the portion of the member 20 above the cup washer E.In practice, this clearance is great enough for the extent of the restriction to flow of fluid to the chamber of the dash-pot cylinder 1 8 via the passage 94 to be determined substantially solely by the dimensions of the bore 94 (or, where, as described below, a flowrestricting clip is utilised, by the dimensions of the bore 94 and the portion of such clip engaged therein). The restriction to flow afforded by the bleed passage 94 is such that the return of the main valve member 20 to its closed position under the influence of the spring 78 occurs only slowly so that the valve closes only after a predetermined time after release of knob 80, for example after 1 5 seconds, for example for a hand-rinse purposes.

The time taken for the valve to close can be altered by altering the effective flow cross-section through the bleed passage 94, and this may conveniently be done by engaging in the passage 94 a bent-in end portion 100 of a clip 102 (Figure 2) formed, for example, of phosphorbronze wire, the clip comprising a part-circular portion, for example extending over an arc of 2250, the portion 100 extending radially inwardly from one end of the part-circular portion. When fitted, the part-circular portion 102 is accommodated in the annular groove 96. By utilising different clips of the same shape but made from wire of different diameters, different values of restriction may be provided, to give different closing times for the valve.

The closing time of the valve may also be varied by varying the length of stroke of the spindle 36.

On the assumption that the cap 80 and with it the sleeve 70 and spindle 36 are depressed until the lower end of the sleeve 70 abuts the shoulder 74, the length of stroke may be adjusted by screwing the sleeve 70 further on to the spindle 36 or unscrewing it further from the spindle, or, which amounts to the same thing, by screwing the spindle 36 along the sleeve 70.To facilitate such adjustment, the upper end of the spindle is preferably formed with a transverse slot for a screw driver and the flange 76 is made hexagonal in plan, or is formed with diametrally opposed flats, for engagement by a spanner. (It will be noted that in the position of the valve shown in Figure 1, since the upper end of the sleeve 70 is shown as being in engagement with the cap 80 when the valve is closed, the sleeve 70 is set for maximum stroke.) The spindle 36 may, instead of being operated by a manually depressable knob 80, as shown, may be actuated by a lever cam mechanism, incorporating a lever operable, for example, by the arm or elbow of the user, this mode of operation being one favoured for hand-washing facilities associated, for example, with hospital operating theatres.Furthermore, a water valve corresponding in construction to the tap described may be disposed remotely from, for example, a spigot mounted to supply a wash-hand basin, such valve being, for example mounted on the floor or the wall and being adapted to be hand, knee, or foot operated.

The variant of the tap shown in Figure 3, in which parts corresponding with parts in Figure 1 have the same reference numerals, has the same construction as the tap of Figure 1, except in the respects noted below.

In the tap of Figure 3, the axis of body 10 is, for aesthetic reasons, inclined forwardly relative to the abutment face 11 at its lower end, which corresponds to the underside of flange 12 in Figure 1, and from which spigot 14 extends perpendicularly downwardly.

Instead of the cylinder 1 8 being provided directly in the body 10, it is provided within a cylindrical dash-pot 19, closed at its lower end, received with clearance in a cylindrical bore 13 in the body 10, which bore 1 3 communicates at its lower end with the interior of spigot 14. The dashpot 1 9 has, at its upper end, an outwardly turned peripheral flange which is clamped between the underside of a member 24a and an annular shoulder formed in body 10 between the bore 13 and a slightly enlarged, co-axial bore which receives the member 24a. The wall of the dashpot 1 9 has, adjacent its upper end, below said flange, one or more apertures (not shown), corresponding in function to the port 44 in the embodiment of Figure 1.

In place of the unitary head member 24 of Figure 1 ,the tap of Figure 3 has a head member which, although of substantially the same form, is formed in two parts, comprising said lower part 24a, which provides the valve seat 22 and the parts 40, and an upper part 24b screwed into the upper part of body 10 and clamping the part 24a against the flange of the dash-pot 1 9, part 24b being sealed with respect to body 10 by an O-ring 25. The two-part construction of the member 24a, 24b, makes it possible to renew the valve seat 22, by replacing the part 24a, simply and at little expense.

The actuating spindle 36 is of slightly different form, having, instead of the hexagonal boss 52 merely a cylindrical part formed with flats on opposite sides. The sleeve 70 of Figure 1 is replaced by an annular collar 71 in screw threaded engagement with a screw threaded part of spindle 36, above the upper part 24b. The collar 71 is normally fixed with respect to spindle 36 by a locking screw 73 screwed into a screw threaded radial bore through the collar 71 and bearing against the spindle 36.Above the screw threaded portion of spindle 36 which receives the collar 71 extends a further screw threaded part, of slightly smaller diameter, which is screwed directly into an operating knob 81 which has an external shape approximately the same as that of the operating knob 80 in Figure 1 and which is held captive in cap 84 in like manner to the cap 80 in Figure 1 but is normally fixed with respect to spindle 36 and prevented from unscrewing by a locking screw 83 screwed into a screw threaded radial bore in cap 81 and engaging the spindle 36 within the cap.

The knob 81 and the spindle 36 are urged upwardly relative to the housing 10 and cap 84 by a single helical compression spring 91 acting between member 24b and the underside of operating knob 81 and passing, with clearance, around the collar 71.

Adjustment of the stroke of the spindle 36 is, in the embodiment of Figure 3, simply effected by unscrewing the cap 84, releasing the locking screw 73, screwing the collar 71 up or down the spindle 36 and thereafter tightening the screw 73 and replacing the cap 84 once more.

It will be appreciated that the valves described with reference to the drawings not only operate to cut off the supply of water after a predetermined period, but also ensure a gradual closure, thereby eliminating concussive or "hammering" effects.

Claims (10)

1. A closure valve including a main valve member reciprocable, via an actuating member, towards and away from a co-operating valve seat, and a dash-pot cylinder in which works a piston formed by or connected with the main valve member, said actuating member being arranged for operation of a subsidiary valve member cooperating with a subsidiary valve seat around a first passage communicating with said dash-pot cylinder, said dash-pot cylinder having a restricted bleed passage communicating therewith and biasing means being provided biasing said actuating member in the direction to move the main and subsidiary valve members towards their respective closed positions, the actuating member being capable of limited lost motion relative to the main valve member, the arrangement being such that, with the valve in a closed condition, an initial movement of the actuating member in a direction to move the main valve member away from its valve seat displaces the subsidiary valve member away from its valve seat before causing movement of the main valve member and piston, so that the dash-pot chamber is readily changed in volume with the fluid thereby displaced passing through said first passage, and the arrangement further being such that when the actuating member is thereafter released, said biasing means first displaces the actuating member relative to the main valve member and piston to engage the subsidiary valve member with its valve seat to close said first passage, before causing movement of the main valve member towards its valve seat, so that, due to the throttling effect of said restricted bleed passage on the fluid which must pass therethrough to allow the corresponding movement of said piston in the dash-pot cylinder, engagement 6f the main valve member with its valve seat occurs only after a delay.

2. A closure valve according to claim 1 wherein, during movement of the main valve member towards its valve seat, the volume of the dash-pot chamber is increased, with the fluid necessary to occupy the increase in volume being drawn into the dash-pot chamber via said bleed passage.

3. A closure valve according to claim 1 or claim 2 wherein said main valve member is integral with said piston and said actuating member is movable along the coincident axes of the dash-pot cylinder and main valve member.

4. A closure valve according to claim 3 wherein said first passage is defined between an axial bore through the combined main valve member and piston, on the one hand, and an axial spindle, afforded by said actuating member on the other hand, with said subsidiary valve seat being provided by the combined main valve member and piston and the subsidiary valve member being carried by said spindle.

5. A closure valve according to claim 3 or claim 4 wherein said restricted bleed passage is formed between a radial bore in said piston on the outer side of a circumferential seal around the piston and an end portion, extended into said bore, of a clip accommodated in a circumferential groove formed around the piston.

6. A closure valve according to any preceding claim, wherein the travel of said actuating member from the closed position thereof to an open position, and thus the full operating stroke, is adjustable, to adjust the time elapsing, after release of the actuating member from an open position at the limit of said travel, until the valve closes.

7. A closure valve according to claim 5, wherein the travel of said actuating member from the closed position thereof to an open position, and thus the full operating stroke, is adjustable, the closure time of the valve being variable or adjustable by adjustment of the effective crosssection of the bleed passage by substitution of said clips of different diameter, or by adjustment of the length of operating strokes, or by a combination of both these measures.

8. A closure valve substantially as hereinbefore described with reference to, and as shown in, Figures 1 and 2 of the accompanying drawings.

9. A closure valve substantially as hereinbefore described with reference to, and as shown in, Figure 3 of the accompanying drawings.

10. Any novel feature or combination of features disclosed herein.