GB2188704A

GB2188704A - Flow control valve assembly

Info

Publication number: GB2188704A
Application number: GB08705028A
Authority: GB
Inventors: Paolo Fornasari
Original assignee: Eltek SpA
Current assignee: Eltek SpA
Priority date: 1986-04-04
Filing date: 1987-03-04
Publication date: 1987-10-07
Also published as: FR2596778B1; IT207788Z2; FR2596778A1; IT8653230V0; AU7056787A; GB8705028D0; DE8703441U1

Abstract

In a flow control valve assembly, preferably for conveying incoming water to inlet ports corresponding to compartments for different substances used during washing machine wash and rinse cycles and wherein the valve includes two thermoactuators 11, 12 each comprising a plunger 15, 16 movable relative to a casing which contains a thermally expandable mass, the plungers actuate, together and/or individually, mechanical components for shifting a valve element 24, 25 to positions 0-3 corresponding to respective outlet ports. Preferably each casing 11, 12 is associated with a thermistor (PTC) 13, 14 electrically connected to the machine's timer. The plungers 15, 16 act on a lever 17 articulated to the valve element 24. <IMAGE>

Description

SPECIFICATION Flow control valve assembly This invention relates to a flow control valve assembly, in particular for use with electronic timers in washing machines.

An electromechanical timer presently used in washing machines has a projecting longitudinal shaft with a cam at one end that actuates, through a roller, a rocker arm articulated on a flow control valve which, according to the position of the cam, deviates the flow of water coming from an inlet controlled by a solenoid valve. Water is directed to the dispenser for detergent, size, or other substances contained in separate compartments, and used during the cycle.

Figure A of the accompanying drawings shows the above-described known assembly, with a water inlet coupling a connected to the water supply, a solenoid valve b controlling the flow of water into the machine, and a nozzle c directing the water into a valve t with a port d across an air break x. The valve t is articulated at e with one end of a rocker lever f pivoted at g and moving against a spring r; the other end of the lever f is connected to a rod i at h. The rod i terminates in a small roller in contact with the profile of a cam I integral with a shaft s that can be actuated in a rotary fashion by a timer m.

The cam 1, actuated by the timer m, urges the lever f into different angular positions, causing the valve t to shift to respective positions in which its port d is in register with respective ports n, o, p, and q. These ports convey the water to the detergent compartment or compartments containing other substances such as size or fabric softener. This type of valve, commonly installed in washing machines, can be actuated by an electromechanical timer having a built-in electric motor, can assemblies, and other components. Washing machine manufacturers now tend to replace the electromechanical timers with electronic ones which are more reliable, but cannot actuate the type of valve described above.

Therefore, it has been necessary to install, in addition to the inlet solenoid b, a solenoid valve for each water conduit port n-q, where each conduit leads to a separate compartment for detergent or other substances.

The solution has two drawbacks: the cost of the machine is considerably increased as some washers need up to five solenoid valves, including the inlet valve b, resulting in an increased probability of malfunctions given the number of solenoid valves installed.

What is desired is a flow control valve that does not require the use of solenoid valves, and can be used in conjunction with electronic timers, which by virtue of their static design only electrically actuate some components of the valve.

A purpose of the present invention is to create a reliable, low-cost device.

The invention provides a flow control valve assembly comprising at least two thermoactuators, each having a casing containing a thermally expandable mass and a plunger extending from and axially movable with respect to the casing; the free ends of the plungers actuating, together and/or individually, mechanical components arranged to shift a flow control valve element to positions corresponding to respective outlet ports.

In a preferred embodiment there are two thermoactuators each consisting of a hermetically sealed casing containing a waxy mass having high thermal dilative properties that urges a plunger in a rectilinear fashion with considerable power; each of the casings is associated with at least one thermistor (PTC), which is connected electrically to an electronic timer; the mobile plungers of the thermoactuators are connected to mechanical components, which in turn can actuate the flow control valve with respect to the different ports (e.g corresponding to compartments containing substances used during wash and rinse cycles of a washing machine).

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 illustrates a preferred embodiment of the valve assembly; Figure 2 shows the positions of a mechanical component when one, both, or neither of the thermoactuators comprised in the valve assembly are energised.

With reference to Fig. 1, a housing 10, preferably made of an electrically insulating plastics material, contains two thermoactuators comprising casings 11, 12 associated with thermistors 13, 14 energised by independent circuits 21, 22 connected to the electronic timer of a washing machine. A plunger 15, 16 protrudes from each casing 11, 12, and is partially immersed in a waxy mass having high thermal dilative properties contained in each casing.

The free ends of the plungers 15, 16 are appropriately spaced, and rest against a depending lever 17 whose lower end 17a is mounted in a guide 18 and whose upper end 17b articulates with a mobile mechanical component 24 commanding a valve element 25.

When either or both of the thermistors 13, 14 are energised through the respective circuits 21, 22 the thermally expandable mass contained in the respective casings 11 and 12 urges either or both of the plungers 15, 16 to move in a rectilinear fashion.

With reference to Figs. 1 and 2, the initial position of the upper end 17b of the lever 17 indicated by "0" corresponds to the de-energised state of both thermoactuators (11/13 and 12/14). The lever 17 can be moved into the angular position indicated by "1" by ener gising the lower thermoactuator (12/14). Position "2" is achieved when both thermoactuators (11/13 and 12/14) are energised. Lever 17 can be moved into the angular position indicated by "3" by energising the upper thermoactuator (11/13) alone. Springs 19, 20 react elastically to the various angular positions of the lever 17 caused by the thermoactuators. The positions of the lever 17 are controlled by the machine's electronic timer, which supplies electric power to the thermistors 13 and 14, bringing valve element 25 into positions corresponding to ports n, o, p, q (Fig A) depending on the cycle programme selected.

The thermoactuators generate considerable power in the form of an axial thrust transmitted to the mobile plungers, and therefore to the lever 17 or equivalent mechanical components.

The housing 10 has a slot 23 allowing lever 17 to move freely.

Water from a solenoid valve is supplied to the inlet indicated by arrow y in Fig. 1 and passes across an air break, required by pollution control standards.

The above described valve assembly provides a valid, low-cost alternative to banks of solenoid valves in washing machines equipped with electronic timers.

Claims

1. A flow control valve assembly comprising at least two thermoactuators, each having a casing containing a thermally expandable mass and a plunger extending from and axially movable with respect to the casing; the free ends of the plungers actuating, together and/ or individually, mechanical components arranged to shift a flow control valve element to positions corresponding to respective outlet ports.

2. An assembly as claimed in claim 1, in which two said thermoactuators act on a mobile element in opposition to the reaction of elastic means, and are operable so as to shift the water flow control valve element to four different positions.

3. An assembly as claimed in claim 1 or 2, in which the thermoactuators are connected to an electronic timer with independent circuits.

4. An assembly as claimed in any preceding claim, including a solenoid valve from which the flow control valve is supplied via an air break.

5. An assembly as claimed in any preceding claim, in which the plungers act on a mobile lever.

6. An assembly as claimed in any preceding claim, in which each thermoactuator has a thermistor as a heat source.

7. A flow control valve substantially as described with reference to, and as shown in, Figs. 1 and 2 of the accompanying drawings.

8. A washing machine having a flow control valve assembly according to any preceding claim.