GB2088531A

GB2088531A - A manual control device for a central heating valve

Info

Publication number: GB2088531A
Application number: GB8135499A
Authority: GB
Original assignee: Saunier Duval Eau Chaude Chauffage SDECC SA
Current assignee: Saunier Duval Eau Chaude Chauffage SDECC SA
Priority date: 1980-12-01
Filing date: 1981-11-25
Publication date: 1982-06-09
Also published as: ES507566A0; GB2088531B; BE891295A; FR2495271B1; LU83792A1; FR2495271A1; NL8105384A; IT1145174B; DE8134876U1; ES8302876A1; IT8168550A0

Abstract

The central heating valve for which the manual control 2 is provided is of a type comprising a T-shaped body 1 with a valve seat 14 to co-operate with a valve closure 17 moved down towards the valve closed position by downward movement of spindle 22 against the upward force of spring 19 urging the closure 17 in a direction away from seat 14. The manual control device has an operating knob 27 manually rotatable about socket 28 fixedly clamped to valve body 1 by threaded coupling elements 6, 9. A push-member 30 which moves with knob 27 is applied to spindle 22 by pressure of spring 29 between the socket and push-member. Two helicoidal ramps 37 on the socket co-operate with lugs 32a, 32b on the operating knob. When the latter is rotated, the lugs interact with the ramps to raise or lower the operating knob and push-member 30 relative to the socket 28 and thereby either push the spindle 22 down or allow it to ascend. The device 2 can be removed from valve body 1 and replaced by a device controlling the valve thermostatically. <IMAGE>

Description

SPECIFICATION A manual control device for a central heating valve This invention relates to a manual control device for a central heating valve, said valve being of the type comprising a body of general T shape with first, second and third pipes, the first pipe forming a seat of the valve, the second pipe supporting the control device and a closure member intended to bear on the seat, the third pipe acting as an outlet pipe, and spring means to restore the closure memberto an open position.

In known manually controlled central heating valves, the regulating closure member is moved with respect to its seat by the operation of a control knob acting on a screw/nut system. Valves of this type cannot be equipped with thermostatic control devices, since the latter require that one of the movements, either opening or closing, of the closure members is effected by spring means dependent upon the control, for example a return spring. This is why in known thermostatically controlled valves, the closure member, when it is not subject to the action of the control device, is returned to the open position by a return spring bearing on the one hand against the bottom of a cup integral with the body, on the other hand against a shoulder of the closure member.

An object of the invention is to provide a manual device for a central heating valve, which manual control device can easily be replaced by a thermostatically controlled device without modifying the valve.

According to the invention there is provided a manual control device for a central heating valve, said valve being of a type comprising, a body of general T-shape with first, second and third pipes, the first pipe forming a seat of the valve, the second pipe supporting said control device and a valve closure member intended to bear on the seat, the third pipe acting as an outlet pipe, and spring means to restore the closure member to an open position, said manual control device comprising a socket mounted integrally with the valve body, an operating knob, said socket comprising at least one ramp of substantially helicoidal shape co-operating with at least one lug of the operating knob, a push rod to control the closure member of the valve, said push rod being integral with the operating knob, and spring means located between the socket and the push-rod.

The invention will now be further described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a side elevation of a central heating valve in combination with a manual control according to the invention; Figure 2 is a view similar to Figure 1 but showing in section on a diametral plane the manual control device and the valve in closed position; Figure 3 is a view similar to that in Figure 2 but with the valve in an open position, and Figure 4 is a view showing a developed projection of a helicoidal ramp provided on the socket of the manual control device in Figures 1 to 3.

The valve illustrated in Figures 1 to 3 and intended for a central heating installation comprises a T-piece union forming a body 1 of the valve. The valve is surmounted by a manual control device 2. The body 1 is provided with an inlet pipe 3 and an outlet pipe 4 for the heat-carrying fluid, this fluid entering the body 1 in the direction of arrow fand leaving the latter in the direction of arrow g. The control device 2 is fitted on the end of the third pipe 5 of the body 1 by means of a screwed ring 6 comprising outer fluting.

The pipes 3 and 5 as well as the entire manual control device 2 have a common axis X-X.

The upper pipe 5 has a screw-tap 7 cooperating with a screw-thread 8 of a part of revolution or cup 9 on the axis X-X comprising at its upper end a threaded flange 10 intended to connect the manual control device 2 to the body 1 of the valve by screwing, by means of the tapped connecting ring 6.

Passing through the up 9 from end to end along its axis is a bore 11 tapped at its upper end and provided with a shoulder 12 at its lower end.

The inner cavity 3, defined between these three pipes 3,4 and 5 of the body 1 of the valve, comprises internally, at the side connected to the inlet pipe 3, an annular flange 14 defining a seat for the sealing member of the valve.

The closure member 15 of the valve is composed at its lower end of a sealing member proper 16 extended upwards by a tail 17 whereof the upper part comprises a peripheral shoulder 18 whereof the lower face constitutes a first support face for spring means constituted by a coil spring 19. The second support for the spring 19 is constituted by the bottom of the shoulder 12 of the cup 9. The sealing member 16 supports a layer of elastomer 20 moulded thereon. Provided in the tail 17 of the sealing member 16 is a blind axial hole 21 receiving a sealing member stem 22 supporting a stop ring 23.

A stuffing-box 4, terminated at its upper end by a hexagonal nut 24a is fixed in the bore 11 of the cup 9 by the screw-tap at its upper end. An axial hole 25 passes through the latter from end to end, the hole 25 opening out at its upper end in a bowl and at its lower end in a cylindrical cavity 26 lined by a cup 26a serving to retain a gasket 26b in its housing. The sealing member stem 22 is mounted to slide and is liquid-tight in the axial hole 25 and projects from the bowl. The stop member 23 mounted on the sealing member stem 22 prevents the latter from being ejected upwards under the action of the static pressure of the fluid passing through the valve.

The manual control device 2 is composed of an operating knob 27, a socket 28, inside which is located a calibrated coil spring 29, the developed force of which is greater than that of the return spring 19 and of a push-rod 30.

On its inside, this operating knob 27 comprises a cylindrical bearing surface 31 and is provided at its upper end with two diametrically opposed lugs 32a and 32b and a cylindrical hub 33. Six engaging hooks 34 are provided at its lower end and towards the inside. Engraved on the outer periphery of the base of the operating knob 27 is a graduated scale 27a covering a circular sector having an angle of 150 at the centre and comprising the letter F (for closed) at one of its ends and the letter 0 (for open) at the other end.

This socket 28, of general cylindrical shape, comprises at its upper end a bore 35 on the axis X-X and an outer cylindrical bearing surface 36 cooperating respectively with the hub 33 and the cylindrical bearing surface 31 of the knob 27. Provided in the cylindrical bearing surface 36, towards the top of the socket 28, are two ramps 37 of general helicoidal shape, which are symmetrical with respect to the axis X-X and whereof the developed profile, illustrated in Figure 4, is composed of three horizontal parts 38,39,40 connected by inclined portions 41,42,43,44. On its outer surface, the base of the socket 28 comprises a shoulder 45 allowing the free rotary assembly by ratchet-like engagement of the connecting ring 6 and a polygonal inner surface 46 comprising eighteen faces, cast in one piece and intended to cooperate with the hexagonal nut 24a of the stuffing box 24.Finally, four slots 47 extending from the base to the lower level of the cylindrical bearing surface 36 are provided along four vertical generatrices staggered by 90O with respect to each other in the sidewall of the socket 28 in order to give the latter the flexibility necessaryfor its ratchet-like engagement on the connection ring 6.

The push-rod 30 is constituted by a central cup 48, intended to receive the calibrated coil spring 29 and connected to an outerflange 50 byfour radial orthogonal arms 51 if very slightly less width than that of the slots 47 in which they are guided. One of the arms 51 is provided with a reference marker 52 extending flush with the lower base of the operating knob 27. The outer flange 50 comprises a shoulder 53 intended to be placed in engagement with the ratchet-like engagement hooks 34 of the operating knob 27. The push-rod 30 acts on the sealing member stem 22 by the lower face 54 of its central cup.

Various parts making up the control device are fitted together in the following manner: the socket 30 is fitted in the operating knob 27 in such a way that the lugs 32a and 32b are opposite horizontal parts 38 of the ramps 37 and that the reference marker 52 is in the vicinity of a division close to the letter F of the graduated scale 27a. The calibrated coil spring 29 is introduced into the socket 28, then the push-rod 30 is engaged on the socket 28, its arms 51 cooperating with the slots 47 in the latter and pressed in against the action of the spring 29 until it is engaged by means of the shoulder 53 of the outer flange 50 in engagement with the six hooks 34 of the operating knob 27. The connecting ring 6 is finally mounted to rotate freely on the lower end of the socket 28 and retained on the latter by the shoulder 45.The arrangement formed in this way is ready to be fitted on the valve body 1.

The manual control device 2 is then fitted to the body of the valve 1.

The arrangement constituted by the manual control device 2 is placed in contact by the lowerface 54 of the push-rod 30 with the sealing member stem 22, which is then pushed back against the action of the return spring 19. The connecting ring 6 is then engaged on the screw-threaded flange 10 of the part of revolution 9 and screwed home on the latter, the arrangement being prevented from rotating by the polygonal surface 46 comprising eighteen faces of the socket 28 engaging on the hexagonal nut 24a of the stuffing box 24.

This valve operates in the following manner.

It is assumed that the operating knob 27 is in its inoperative position: the letter F ofthe graduated scale 27a is located opposite the reference marker 52 supported by the push-rod 30. In this position, the lugs 32a and 32b of the operating knob are located opposite the lower horizontal parts 38 of the ramps 37, from which they are separated by a small distancej or clearance. The valve is thus closed (shown in Figure 2) under a predetermined load, equal to the force developed by the spring 29, transmitted by the push-rod 30 and the intermediary of the sealing member stem 22 to the closure member 15. In this position, the operating knob 27 is not stressed axially by the spring 29.

When the operating knob 27 is rotated from F towards 0, after taking up the ciearancej, its lugs 32a and 32b come into contact with the inclined parts 42 of the ramps 37 of the socket 28, which has the effect of transmitting an upwards axial translational movement of the operating knob 27 and to the push-rod 30 which is associated therewith by ratchet-like engagement, releasing the sealing member stem 22, thus allowing the closure member 15 to move away from its seat 14 under the action of the spring 19 and to open the valve. When the lugs 32a and 32b have come into contact with the upper horizontal parts 39 of the ramps 37, the valve is in the fully open position (configuration shown in Figure 3).A further rotation of the operating knob 27 systematically returns the valve to the inoperative position, namely the closed position, since the lugs 32a and 32b project beyond the horizontal parts 40 and are thus once more located opposite the lower horizontal parts 38 of the ramps 37.

It will now be described how to achieve the nominal lift of the valve necessary for regulating the central heating installation. With the operating knob 27 in its inoperative position, its rotation in the direction from F towards 0 brings the lugs 32a and 32b into contact with the ramps 37. This point of contact corresponds to the zero position from the onset of opening. It is thus sufficient to take the line of the graduated scale 27a which is opposite the reference marker 52 in order to have the origin of opening. Since the spacing between each iine of the graduated scale 27a corresponds to a predetermined lift of the closure member 15, it is thus easy to obtain accurately the nominal lift to be effected by rotating the operating knob 27.

The invention has a certain number of advantages, in particular: - the manual control can be replaced easily by a thermostatic control without changing the valve nor the calibration of the central heating installation; - the nominal lift of the valve is established easily by virtue of the graduated scale of the operating knob and makes it possible to regulate the central heating installation easily; - when closed, the bearing force of the sealing member on its seat is exerted by a calibrated spring, therefore independently of the user, which guarantees a long service life for the elastomer lining 20 of the sealing member; - when the valve is in the fully open position, an additional rotation of the operating knob automatically restores it to the inoperative position (closed position), without it being possible to force the mechanism.

One variation of the invention consists of replacing the two ramps 37 of general helicoidal shape of the socket 28 by a single ramp, the operating knob comprising only one lug cooperating with this ramp.

Claims

1. A manual control device for a central heating valve, said valve being of a type comprising, a body of general T-shape with first, second and third pipes, the first pipe forming a seat of the valve, the second pipe supporting said control device and a valve closure member intended to bear on the seat, the third pipe acting as an outlet pipe, and spring means to restore the closure member to an open position, said manual control device comprising a socket mounted integrally with the valve body, an operating knob, said socket comprising at least one ramp of substantially helicoidal shape co-operating with at least one lug of the operating knob, a push rod to control the closure member of the valve, said push-rod being integral with the operating knob, and spring means located between the socket and the push-rod.

2. A manual control device as claimed in claim 1, in which the socket is located inside the operating knob having a cylindrical bearing surface ensuring rotary guidance of the knob on the socket.

3. A manual control device according to claim 1 or claim 2, in which the push-rod comprises a central cup having a lower face to ensure control of the closure member of the valve.

4. A manual control device as claimed in claim 3 in which the push-rod is connected to the operating knob by a flange connected to the central cup by radial arms passing through slots in the socket.

5. A manual control device as claimed in claim 4 in which a said radial arm supports a reference marker.

6. A manual control device as claimed in any one of claims 1 to 5, in which the spring means is a spring compressed between an inner upper part of the socket and a/the central cup in the push-rod.

7. A manual control device as claimed in any one of claims 1 to 6, in which the socket is fixed to the body of the valve by a screw threaded ring.

8. A manual control device as claimed in any one of claims 1 to 7, in which the helicoidal ramp has a profile comprising horizontal parts connected by inclined parts.

9. A manual control device as claimed in any one of claims 1 to 8, in which the socket comprises two said ramps which are symmetrical one to the other with respect to the axis of the socket.

10. A manual control device for a central heating valve, substantially as hereinbefore described with reference to Figures 1 to 3 of the accompanying drawings.