WASHING MACHINE WATER INLET ISOLATING VALVE

Abstract: An isolating valve (31) for the water supply to a washing machine and adapted for attachment between a main control valve (12) and the inlet end of a supply hose (11) the outlet end of which is to be connected to the washing machine (10). The valve has a piston (40) adapted to open and close a valve port (37) communicating with the supply hose (11) and through which, in use, a small bore tube (49) is positioned to extend to a control valve assembly (25) having a control port (45) communicating with the interior of the supply hose (11) and adapted to be opened and closed by a solenoid valve operable in response to the washing machine control cycle. The piston (40) is adapted to open and close the valve port (37) in response to a difference in water pressure on either side of the piston (40) and in response to water pressure fluctuations in the control valve assembly (25), via the small bore tube (49), as the control port (45) is opened and closed by the solenoid valve. Piston (40) closes progressively on seat (35) reducing noise and water-hammer. An embodiment using a diaphragm (20) rather than a piston (40) is disclosed.

Description: "WASHING MACHINE WATER INLET ISOLATING VALVE" TECHNICAL FIELD This invention relates to improvements in the way water is introduced into a washing a machine, including clothes washing machines as well as dishwashers, and more particularly relates to an isolating valve at the water inlet end of a hose extending from a main control valve to the washing machine. BACKGROUND ART Conventional isolating valves situated at the washing machine end of a supply hose consist of a rubber diaphragm which seals over an outlet by virtue of the upstream water pressure. Relieving the pressure upstream of the diaphragm, via a solenoid valve, results in the diaphragm lifting off the outlet and allowing water to pass through the isolating valve. The valve is normally connected to a main supply valve via a pressurised supply hose. The supply hose can rupture causing flooding of the area surrounding the machine, and in addition the diaphragm has a tendency to slam when opening and closing the outlet which is noisy, and also causes fatigue within the hose and valve assembly which can lead to rupture of the hose, particularly at the hose connections, and/or damage to the valve assembly. DISCLOSURE OF THE INVENTION It is a primary object of the present invention to provide an isolating valve adapted to be positioned at the inlet end of a supply hose to a washing machine which will minimize flooding in the case of hose and/or hose connection failure. In accordance with the invention there is provided an isolating valve for the water supply to a washing machine and adapted for attachment between a main control valve and the inlet end of a supply hose to the outlet end of which hose is to be connected to the washing machine, wherein said valve has a valve member adapted to open and close a valve port communicating with said supply hose and through which, in use, a small bore tube is positioned to extend to a control chamber having a control port communicating with the interior of the supply hose and adapted to be open and closed by a solenoid valve operable in response to the washing machine control cycle, wherein said valve member is adapted to open and close said valve port in response to a difference in water pressure on either side of the valve member and in response to water pressure fluctuations in said control chamber, via said small bore tube, as said control port is open and closed by said solenoid valve. In a first preferred form of the present invention an isolating diaphragm valve is provided and adapted to be positioned at the main control valve end of the supply hose to communicate with a small bore tube exposed to water supply pressure, via small holes through the diaphragm, and extending through the supply hose to a control chamber at the washing machine end of the supply hose. The control chamber in turn communicates with the water inlet to the washing machine via a control port adapted to be opened and closed by a solenoid valve operable in response to actuation of the washing machine control cycle to open the control port and relieve water pressure within the small bore tube whereby the diaphragm will flex to open a main supply port through the isolating diaphragm valve to allow water to flow through the supply hose to the washing machine. Upon deactivation of the solenoid valve, during various stages of the washing machine cycle, the solenoid valve when deactivated closes the control port and the diaphragm valve closes to shut off water supply to the machine. With such an isolating valve and small bore tubing assembly, upon rupturing of the supply hose, or failure of the connections at the main control valve and/or at the machine, water pressure within the hose is reduced, the solenoid valve actuates under spring pressure to close the control port and water pressure within the small bore tube increases to act on the diaphragm within the isolating valve to thereby close the main supply port from the isolating valve. As a result water supply to the washing machine is cut off at the isolating valve upstream of the supply hose and its connections to the isolating valve thus minimising flooding in the surrounding area of the washing machine. Although the isolating valve of the first preferred embodiment of the invention minimises flooding in the event of supply hose rupture and/or failure of the supply hose connections, the use of an isolating valve incorporating a diaphragm which acts abruptly when opening and closing the main supply port can still impose unnecessary fatigue on the supply hose and its connections, as well as the isolating valve itself, but more importantly the noise generated within the water supply system during opening and closing of the valve is still unacceptable in most environments. It is therefor an object of a second preferred embodiment of the present invention to provide an isolating valve adapted to be positioned at the inlet end of a supply hose to a washing machine which will not only minimise flooding in the case of hose and/or hose connection failure, but which also minimises the generation of unacceptable noise when the isolating valve opens and closes. The second preferred embodiment of the invention provides an isolating valve for the water supply to a washing machine and adapted for attachment between a main control valve and the inlet end of a supply hose the outlet end of which hose is to be connected to the washing machine, wherein said valve includes a piston chamber containing a piston adapted to close a valve port communicating with said supply hose through one end of which piston a small bore tube is positioned to extend through the supply hose to a control chamber at the washing machine end of the supply hose and having a control port communicating with the outlet end of the supply hose adapted to be opened and closed by a solenoid valve operable in response to the washing machine control cycle, wherein said piston chamber incorporates apertures to expose both sides of said piston to water supply pressure, wherein said apertures are so sized that upon opening of said control port water pressure within said small bore tube and therefor the piston chamber on the side of the piston remote from the valve port will drop progressively to a value below the water supply pressure, whereby said piston will progressively move away from said valve port to allow water to be supplied to said washing machine through said supply hose, and wherein, upon closing of said control port, water pressure within said small bore tube and therefor the piston chamber on the side of the piston remote from the valve seat, will rise progressively back to water supply pressure to allow the piston to move progressively back to close said valve port. It will be apparent that as opening and closing of the valve port occurs progressively, as distinct from abruptly as is the case with a diaphragm valve, fatigue in the supply hose, its connections and the isolating valve itself, will be reduced and the noise generated during such abrupt opening and closing of the valve will also be significantly be reduced. As with the isolating valve of the first preferred embodiment, in the event of rupturing of the supply hose or failure of the supply hose connections, water pressure in the hose and through the connections will drop to a value below water supply pressure, and the lower pressure on the side of the piston adjacent the valve seat relative to that on the other side of the piston exposed to water supply pressure will cause the piston to move to a position closing the valve port. BRIEF DESCRIPTION OF THE DRAWINGS Two preferred embodiments of the invention will now be described with reference to the accompanying drawings, in which; Figure 1 is a schematic view of the overall arrangement of the main supply valve, isolating valve, supply hose, water control valve assembly and washing machine, Figure 2 is a cross-sectional view of an isolating valve of a first preferred embodiment of the invention together with an associated supply hose and water control valve assembly at the washing machine, and Figure 3 is also a cross-sectional view of an isolating valve of a second preferred embodiment of the invention associated with a supply hose and a water control valve assembly at the washing machine. BEST MODE FOR CARRYING OUT THE INVENTION Firstly with reference to Figure 1 of the drawings, there is shown a clothes or dishwashing installation, incorporating a washing machine 10, a supply hose 11, a main supply valve 12, control valve assembly 25, and an isolating valve 14 in accordance with the preferred embodiments of the invention incorporated between the supply valve 12 and the inlet end of the supply hose 11. Turning to Figure 2 of the drawings, the isolating valve 14 comprises a housing 15 connected at one in water tight engagement with the main supply valve 12 via a threaded connection 16. The housing 15 has an inlet chamber 17, an outlet chamber 18, a pressure sensing chamber 19, and a flexible diaphragm 20 separating the inlet and outlet chambers 17 and 18 from the pressure sensing chamber 17 and adapted, under the influence of pressure differences on either side of the diaphragm, to open and close an inlet port 21 to the outlet chamber 18. When the diaphragm is flexed away from the inlet port 21, water from the main supply valve 12 can pass from the inlet chamber 17 to the outlet chamber 18 and then outwardly from the housing 15 to the inlet end of the supply hose 11 clamped around an outlet port 22 from the housing. When the diaphragm 20 closes the inlet port 21 water is prevented from passing from the inlet chamber 17 to the outlet chamber 18 and therefrom into and through the supply hose 11. The pressure sensing chamber 19 is exposed to water supply pressure via small holes 23 through the diaphragm and communicating with a small bore tube 24 which extends through the supply hose 11 to a control chamber 25a forming part of a control valve assembly 25 comprising a water transfer passage 26 connected at one end to the outlet end of the supply hose 11 and at its other end to a short length of transfer hose 27 connecting the transfer passage 26 to the inlet to the washing machine. The control chamber 25a connects with the interior of the small bore tube 24 via a port 28 and with the interior of the water transfer passage 26 via a control port 29 adapted to be open and closed by a solenoid valve 30 operable in response to actuation of the washing machine control cycle to open the control port 29 and relieve water pressure within the small bore tube 24 and thereby the pressure sensing chamber 20 such that, when the inlet chamber 17 causes the diaphragm 20 to flex away from the inlet port 21 allowing water to flow into the outlet chamber 18, and thereafter through the supply hose 11 to the washing machine. Upon deactivation of the solenoid valve, during various stages of the washing machine cycle, the valve member 30 of the solenoid valve 30, when deactivated and under the -biasing action of a spring 30a closes the control port 29, pressure within the small bore tube 24 and the pressure sensing chamber 20 increases to a degree whereby the diaphragm is forced back to a position closing the inlet port 21 and water supply to the outlet chamber 18 and thus to the supply hose 11 is cut-off. With such an isolating valve 14 and small bore tube 24 assembly, upon rupturing of the supply hose 11 and/or failure of the hose connections at the main supply valve 12, the water transfer passage 16 and/or the washing machine 10, water pressure within the hose 11 is reduced and the pressure within the control chamber 25a via the control port 29 is also reduced, such that the solenoid valve 30 acts under the pressure exerted by the spring 30a to close the control port 29. As a result water, pressure within the pressure sensing chamber 19, the small bore tube 24 and the control chamber 25a increases to an extent whereby the diaphragm 20 flexes back to close the inlet port 21 and water supply to the outlet chamber 18, and thus to the supply hose 11, is cut-off at the isolating valve 14, thus minimizing flooding in the surrounding area of the washing machine. Turning to the embodiment of Figure 3 of the drawings which, not only enables shutting-off of the water supply through the supply hose at the main supply valve 12, also dispenses with the need for an isolating valve incorporating a diaphragm, and the problems associated therewith with regard to fatigue of the supply hose and failure of the connections, as well as noise generated, there is provided the isolating valve 31 comprises a housing 32 connected at one end in watertight engagement with the main supply valve 12 via a threaded connector 16 as with the first embodiment. The opposite end of the housing 32 has an outlet passage 33 the entrance to which forms a valve port 34 with a valve seat 35 protruding into the housing 32 and over which is positioned a cylindrical piston chamber 36 having an open end with a series of slot shaped apertures 37 adjacent the valve seat 35 and an end wall 38 having one or more small apertures 39 therethrough. Both the slot shaped apertures 37 and the small aperture 39 are exposed to water supply pressure when the main supply valve 12 is open. The piston chamber 36 receives a piston 40 adapted to slide backward and forward within the piston chamber as water pressure on either side of the piston changes. The outlet passage 33 is attached, for example by a hose clamp, to the inlet end of the supply hose 11 having its outlet end attached, for example once again by a hose clamp, to a water control valve assemble 25 comprising a control valve housing 42 communicating with the supply hose at one end and the washing machine at the other end and containing a control chamber 43 with a passage 44 through which water can pass from the supply hose to the washing machine via a connecting hose 44a. The control chamber 43 has a control port 45 adapted to be opened and closed by a valve member 48 forming part of a solenoid valve comprising an electromagnetic coil 47 surrounding the control valve housing 42 and activated by an electrical control current from the washing machine control system to move a magnetic core member 48 axially within the housing 42 and connected to the valve member to open and close the control port 45 as dictated by the washing machine control cycle. The interiors of the control chamber 43 and the piston chamber 36 are in communication with each other via a small bore tube 49 extending through the piston 40 to the side remote from the valve seat 35. When the solenoid valve is closed the water pressure within the piston chamber 36 on either side of the piston 40 is equivalent to the water supply pressure as is the water pressure within the small bore tube 49 and the control chamber 43, and as the surface area of the piston on the side remote from the valve seat 35 is greater than that adjacent the valve seat the piston 40 is forced against the valve seat 35 to close the valve port 34 and no water is supplied through the supply hose 11. Upon actuation of the solenoid valve to open the control port 45 the pressure within the control chamber 43 drops, and as a consequence the pressure within the small bore tube 49 drops, and as the aperture 39 through the end wall 38 of the piston chamber 36 is of such a small dimension as to not quickly compensate for the drop in water pressure in the piston chamber on the side of the piston remote from the valve seat 35, the water supply pressure on the opposite side of the piston via the slot shaped apertures 37 acts to progressively move the piston away from the valve seat 35, rather than abruptly as is the case with conventional diaphragm valves, thus allowing water to flow through the isolating valve 14, supply hose 11 and control valve assembly 41 to the washing machine. Upon deactivation of the solenoid valve by the machine control system during the washing cycle, to close the control port 45, water pressure in the piston chamber 36, small bore tube 11 and control chamber 43 progressively increases to water supply pressure and as pressure on either side of the piston approaches equalization the greater piston area on the side thereof remote from the valve seat 35 results in the piston moving progressively back to a position seated on the valve seat 35 and closing the valve port 34, and as a result water supply to the washing machine is stopped at the isolating valve. Therefor, at all times except when the control system of the washing machine requires water to be supplied to the machine during the washing cycle, water supply pressure within the supply hose and at its connections is relieved and in the event of rupturing of the supply hose and/or failure of its connections flooding of the surrounding area is restricted to only water remaining downstream of the isolating valve above the point of rupture and/or connection failure. In addition, as the movement of the piston 40 to close and open the valve port occurs progressively as the relative water pressure on either side of the piston changes progressively, when the solenoid valve assembly is activated and deactivated, as distinct from the abrupt opening and closing operation of a diaphragm valve, the unacceptable noise generated during operation of the isolating valve is also minimised. In situations where a washing machine is supplie d with both hot and cold water an isolating valve will be installed at the inlet ends of the supply hoses for both the hot and cold water.

Claims: CLAIMS 1. An isolating valve for the water supply to a washing machine and adapted for attachment between a main control valve and the inlet end of a supply hose the outlet end of which is to be connected to the washing machine, wherein, said valve has a valve member adapted to open and close a valve port communicating with said supply hose and through which, in use, a small bore tube is positioned to extend to a control chamber having a control port communicating with the interior of the supply hose and adapted to be open and closed by a solenoid valve operable in response to the washing machine control cycle, wherein the said valve member is adapted to open and close said valve port in response to a difference in water pressure on either side of the valve member and in response to water pressure fluctuations in said control chamber, via said small bore tube, as said control port is opened and closed by said solenoid valve. 2. An isolating valve as claimed in claim 1, wherein said valve member is a diaphragm having apertures therethrough to expose both sides of diaphragm to water supply pressure and adapted to open and close said control port in response to water pressure fluctuations in said control chamber via said small bore tube. 3. An isolating valve as claimed in claim 1, wherein said isolating valve comprises a piston chamber containing a piston member, said piston member being exposed to water pressure on both sides thereof whereby said piston member will open and close said control port in response to water pressure fluctuations within said control chamber via said small bore tube. 4. An isolating valve for the water supply to a washing machine, said valve being substantially as hereinbefore described with reference to Figures 2 and 3 of the accompanying drawings.

Inventors: BLAIR SIMON ANTHONY, BLAIR, SIMON, ANTHONY
Applicants: BAILLIEU TIMOTHY JAMES, BAILLIEU, TIMOTHY, JAMES
Application year: 1992
Main classification: F16K47
IPC codes: D06F39, F16K31, F16K47