GB2051311A - Multi-port control valve - Google Patents

Abstract

A control valve for a central heating system has a rotor (118) with four parallel sets (A, B, C, D) of apertures (132) which register respectively with four outlets (113, 115, 114, 116) in the housing (110), the interior of which receives fluid through a common inlet (112). The apertures (132) are arranged to give, within one revolution of the rotor, all possible combinations of control of the outlets, from all open to all closed. A motor (130) driving the rotor (118) is controlled e.g. by a cam disc (334) with four parallel peripheral tracks of recesses (339), each track being associated with a respective microswitch (335, 336, 337, 338) which is operated by the recesses (339) of that track at the various operative positions of the rotor (118). The microswitches can be connected in a thermostatically operated control circuit to the motor to supply hot water to four independently controlled zones to be heated. <IMAGE>

Description

SPECIFICATION Multi-port control valve This invention relates to valves for controlling the flow of fluid to a number of passages. It is particularly, but not exclusively, relevant to controlling the supply of hot liquid to different radiators in a central heating system.

According to the present invention there is provided a multi-port control valve comprising a housing having a fluid inlet and a plurality of fluid outlets, a valve member movably located in the housing over the outlets and having a number of apertures therein to register with selected outlets and thereby provide fluid communication between the inlet and the selected outlets, the apertures in the valve member being arranged so that at different selected positions of the valve member different outlets or combinations of outlets are uncovered, a drive motor for moving the valve member through the various said positions, and a control device for stopping the drive to the valve member at any selected position according to a signal received by the control device.

Preferably the control device comprises a reference member and scanning means associated one with the valve member and the other with the valve housing so that as the valve member moves the scanning means scans the reference member, the reference member having a number of reference elements corresponding to the different said positions of the valve member so that the drive tq the valve member can be stopped when the scanning means locates the appropriate element on the reference member.

In one form the scanner comprises a number of microswitches corresponding to the number of fluid outlets, and the reference member comprises a cam with contoured reference elements which operate the microswitches, whereby the microswitches can be connected into the drive motor circuit so as to stop the motor at a selected position of the valve member. A control circuit for the motor may comprise a series of circuit elements in parallel with each other and in series with the motor, each said circuit element comprising a two pole said microswitch in series with a two pole thermostat, the two switching poles of the thermostat being connected to the respective two switching poles of the microswitch.

In another form the control device is associated with a counter which counts the signals received from the scanning means locating successive reference positions and stops the drive to the valve member when the count indicates that the selected position has been reached. The count is preferably arranged to start when the scanning means passes a datum position on the reference member, so that any one position of the valve member is represented by a fixed and unique count from that datum position.

The valve member is preferably rotary so that it rotates unidirectionally and cyclicly through its various positions. In one form the valve member is an apertured disc which rotates over the outlets which are presented in a common plane adjacent that of the disc. In another form the valve member is a drum with apertures around its cylindrical surface which moves adjacent a cylindrical surface of the housing in which are the outlets. If desired there may be two valve members controlling different outlets with a common inlet between the two valve members.

In order that the invention may be more clearly understood, two embodiments will now be described with reference to the accompanying drawings, wherein: Fig. 1 shows a diametrical cross-sectional view through one embodiment of valve, Fig. 2 shows the arrangements of the apertures around the cylindrical surface of the valve member of Fig. 1, Fig. 3 shows a diametrical cross-section through a second embodiment of valve, Fig. 4 shows a cross-sectional side view of a modification to the embodiment of Figs. 1 and 2, Fig. 5 shows a diagrammatic plan view of the motor and control equipment of the Fig. 4 embodiment, and Fig. 6 is a circuit diagram of an electric control circuit suitable for use with the embodiment of Figs. 4 and 5.

Referring to the drawings, and firstly to Fig. 1; the valve comprises a generally cylindrical housing 110, having an axial inlet port 112 at one end and four radial outlet ports 1 13, 1 14, 1 15, 1 16. The outlet ports are arranged two on each diametrically opposite side of the housing, and each port is in a different radial plane A, B, C, D respectively. Within the housing is a valve member 11 8 in the form of a cylindrical drum which fits closely and rotatably inside the housing, one end wall 119 of the drum having a central aperture which closely and rotatably receives an inward spigot extension 120 of the port 112. The other end of the drum is closed, and has a shaft 122 projecting outwardly therefrom through a sleeve 124 around an opening at the end of the housing 110.Sealing rings 125 provide a liquid tight seal between the shaft 1 22 and sleeve 124.

The projecting end of the shaft 122 is keyed to a drive shaft 126 projecting from a gear box 128 of an electric motor 130, mounted to a control box 131 which in turn is mounted to the end of the housing 110. The cylindrical surface of the drum is provided with four rows of apertures 132, each row lying on the radial plane A, B, C or D of one of the outlet ports 113 to 11 6 so that rotation of the drum can bring successive apertures of each row into register with its respective outlet port.

A suitable arrangement of the apertures 1 32 is indicated in Fig. 2, where the cylindrical surface of the drum 11 8 is developed as a plane. Sixteen axial positions around the drum periphery are shown, represented by the reference numerals 1 to 1 6. At position 1 there is no aperture 132, and in successive positions there are different apertures or combinations of apertures. Thus, each of the sixteen positionswill represent a different control of the four outlets 11 3 to 11 6, ranging from no outlet ports open at position 1 to all four outlet ports open at position 1 6.

The drive to the valve is controlled by a control device in the box 131 which comprises electrically insulating disc 134 secured to the projecting end of the shaft 122. The surface of the disc remote from the drum 118 is wiped by electrical contacts 135, 136 and 137 at different radial positions. A ring of sixteen electrically conductive elements (not shown) is set in the surface of the disc so as intermittently to interconnect the contacts 135, 136 as the disc rotates with the drum 118 when each position 1 to 1 6 on the drum registers with an outlet port. One of the electrically conductive elements is extended radially inwardly so as to be wiped by the contact 137 once in every revolution of the drum 118. The contacts are connected to suitable electronic circuitry (not shown) for detecting the position of the drum and controlling the motor 130 accordingly.

A suitable mode of operation is as follows. The disc 1 34 is arranged so that the contact 1 37 makes electrical connection with the disc at a known position of the drum. When the contact 137 makes electrical contact with the disc, a signal is sent to the electronic control circuitry which sets a counter in the circuit so that successive interconnections of the contacts 135, 1 36 are registered on the counter.As mentioned above, each of the elements interconnecting the contacts 135, 136 is set at a position corresponding to one of the positions 1 to 16 on the drum 11 8. Thus, each of the sixteen positions of the drum is represented by a different and unique count on the counter, since the counter will always start from the datum position represented by the position of electrical connection of the contact 137 with the disc 134. By presetting the appropriate count number into the electronic control circuitry, for example by a manually operated dial, the motor will then move the drum 118 to the appropriate position to supply the desired outlet or combination of outlets.Instead of simply presetting a single number into the control circuitry, it is more likely that a control program will be used whereby different count numbers are applied to the circuitry at different times, for example when a thermostat indicates that a particular radiator or area served by an outlet, has reached a suitable temperature, an appropriate count number will be applied to the circuitry so that the drum is rotated to shut off that outlet.

Instead of having the control disc associated with the motor and the contacts associated with the housing, they could of course be mounted the other way around. It will be apparent that in operation of the control device the electrical contacts scan the surface of the disc. Instead of electrical contacts and a disc having electrically conductive elements, other scanning devices could be used, for example using an optical detector, microswitches, induction detection, or any other suitable position detecting principle.

Referring to Fig. 3; this valve comprises a generally flat circular housing 210 having a radial inlet port 21 2 and four axial outlet ports (only three ports 213, 214, 215 are shown) in one face of the housing. A disc 21 8 is rotatable within the housing closely against the face of the housing having the outlet ports. The disc has apertures 232 arranged in rings A, B, C, D of different radius.

The four outlets are likewise located at the different distances A, B, C, D from the axis of the disc so as to register with respective rings of apertures in the disc. A shaft 222 passes through an opening in the wall of the housing opposite the outlets, and at its outer end is connected to a motor 130 through a gear box 128, and carries a control disc 1 34 which is scanned by a suitable scanning device 133, which can for example ibe electrical contacts 135, 136, 137 as in Fig. 1.The disc 218 has sixteen radial positions corresponding to the sixteen axial positions on the drum 118 in Fig. 2, and the apertures 232 are arranged on fifteen of these sixteen radii so as to uncover different outlets or combinations of outlets at different positions of the rotor disc. In other respects, the operation and control is essentially similar to the valve of Figs. 1 and 2.

The foregoing embodiments illustrate the control of up to four outlets. Less than four outlets could be controlled thus. However, more than four outlets controlled by a single rotary valve member would in most cases result in an excessively large number of different positions and apertures to give all the possible combinations of outlet openings. If it is desired to control more than four outlets, two rotors could be mounted in the housing, each rotor controlling up to four outlets and a common inlet supplying fluid to the space between the rotors.

For example, in the embodiment of Fig. 1, a second apertured drum could be mounted within the drum 11 8 and uncovering outlet ports in a cylindrical housing component located inside the inner drum, the inlet 112 being offset from the axis of the housing so as to supply fluid to the annular space between the two drums. Similarly, in the embodiment of Fig. 3, two discs 218 could be mounted on a common axis, uncovering outlets in opposite walls of the housing, the inlet 212 supplying fluid to the space between the two discs.

Referring to Figs. 4 and 5; this embodiment is in many respects similar to that of Figs. 1 and 2, and like parts are given the same reference numerals and will not be described further. The principal difference lies in the replacement of the disc 134 and contacts 135, 136 and 137 by a cam disc 334 secured to the rotor shaft 122, and four microswitches 335, 336, 337, 338, respectively, fixed relative to the valve casing. The microswitches are at four different axial levels and are acted on by recesses 339 along four different parallel tracks around the edge of the cam plate, the recesses corresponding to the different positions of the rotor in register with the outlets.

Fig. 6 shows how the microswitches can be connected into the motor circuit to control the operation of the valve in a hot water central heating system. The circuit comprises four circuit elements A', B', C', D' corresponding to the fluid outlets at A, B, C, D respectively of the valve. The four circuit elements are in parallel with each other and in series with the drive motor 130. Each circuit element comprises one of the microswitches 335, 336, 337, 338, and one of the four room or area thermostats 341, 342, 343, 344 respectively. The microswitches and thermostats are of the two-pole type, and in each circuit element the two switching poles of the microswitch are connected separately to the two switching poles of the thermostat.

The operation of the control circuit is as follows. Let it be assumed, for example, that in the "raised" position shown, the thermostats are indicating that the desired temperature has been achieved, and that in the "lowered" position shown the microswitches are indicating that their respective outlet ports are closed by the valve rotor. Thus no hot water is being supplied to any of the four thermostatically controlled areas.

Suppose now that the temperature drops in the area controlled from A. Thermostat 341 moves to the "down" position, completing the circuit to the motor, which will then drive the rotor until microswitch 335 moves to the "up" position, indicating that the outlet port 113 at A is open, the rest of the microswitches being still in the down position. Note that in the course of its movement the disc 334 will probably move through a series of positions in which the microswitches 336, 337, 338 move into the down position. This merely provides alternative current paths to the rotor, ensuring that the motor continues to rotate until only microswitch 335 is lowered, and the circuit to the motor is therefore broken. When the temperature controlled by thermostat 341 has risen sufficiently, thermostat 341 moves to its raised position completing the circuit to the motor until the rotor is rotated to move the microswitch 335 to its lowered position, indicating that the outlet port 113 is closed.

Claims (8)

1. A multi-port control valve comprising a housing having a fluid inlet and a plurality of fluid outlets, a valve member movably located in the housing over the outlets and having a number of apertures therein to register with selected outlets and thereby provide fluid communication between the inlet and the selected outlets, the apertures in the valve member being arranged so that at different selected positions of the valve member different outlets or combinations of outlets are uncovered, a drive motor for moving the valve member through the various said positions, and a control device for stopping the drive to the valve member at any selected position according to a signal received by the control device.

2. A control valve according to claim 1, wherein the valve member is rotary so that it rotates unidirectionally and cyclicly through its various positions.

3. A control valve according to claim 2 wherein the valve member is an apertured disc which rotates over the outlets which are presented in a common plane adjacent that of the disc.

4. A control valve according to claim 2 wherein the valve member is a drum with apertures around its cylindrical surface which moves adjacent a cylindrical surface of the housing in which there are the outlets.

5. A control valve according to any one of the preceding claims wherein the control device comprises a reference member and scanning means associated one with the valve member and the other with the valve housing so that as the valve member moves the scanning means scans the reference member, the reference member having a number of reference elements corresponding to the different said positions of the valve member so that the drive to the valve member can be stopped when the scanning means locates the appropriate element on the reference member.

6. A control valve according to claim 5 wherein the reference member is a rotary cam having a number of parallel tracks corresponding to the number of outlets, the scanning means comprising a number of microswitches associated with respective tracks and co-operating with contoured portions of the tracks to operate the microswitches at said positions of the valve member.

7. A control valve according to claim 6, in conjunction with a thermostatically operated motor control circuit comprising a series of circuit elements in parallel with each other and in series with the motor, each said circuit element comprising a two pole said microswitch in series with a two pole thermostat, the two switching poles of the thermostat being connected to the respective two switching poles of the microswitch.

8. A control valve substantially as described herein with reference to the accompanying drawings.