GB2090874A - Automatic washing machine with improved water supply circuit - Google Patents

Abstract

A washing machine provided with a water supply circuit 9 comprising a controlled inlet valve 5, an air gap portion 6, a decalcifier 11, a salt container 12 and a tank 8 for metering the decalcifier regeneration water. The tank 8 communicates at its top with the outside atmosphere and with the air gap portion 6. The supply circuit further comprises, preferably downstream of the connection of the decalcifier to the salt container, a closure member 19 for the supply conduit 7 of the machine tub 4 and which is controlled by a pump 20 of the machine for closing the supply circuit in one phase, prior to regeneration of the decalcifier, in which the inlet valve is opened. The closure member 19 may comprise an expansible resilient bellows member connected to the discharge of the pump 20. <IMAGE>

Description

SPECIFICATION Automatic washing machine with improved water supply circuit The present invention relates to an automatic washing machine, particularly of domestic type, with an improved water supply circuit.

As is known, washing machines, more particularly dish washing machines, normally incorporate a decalcifier for the supply water, the active substances in which (ionic exchange resin or the like) have to be periodically regenerated with a metered amount of water which is firstly passed through a suitable salt container.

The regeneration water may be taken directly from the water mains system by way of an electrically operated valve which is controlled by the programmer of the machine to open in a given phase of the operating cycle for a suitable period of time. However, metering of the regeneration water, which is controlled exclusively on a time basis, is found to vary in an undesirable manner, since it does not take into account the changes in pressure which normally occur in the water mains system.

For more accurate metering, it is therefore preferred that the volume of regeneration water should be defined by means of a tank which is open at the top and which is provided at a predetermined level with an overflow connected to the washing tub of the machine.

In order to avoid connecting a suitable electrically actuated control valve directly to the water mains system (in which case the reliability of the electrically operated valve could be compromised by the high mains pressure), the tank is preferably supplied by the water losses from the conduit separator with which the supply conduit for the washing tub is provided. The bottom of the tank is connected to the salt container by way of an electrically operated valve; when that valve is open, the metered amount of water collected in the tank flows under the force of gravity through the salt container and thus into the decalcifier, to effect regeneration thereof.

The electrically operated valve which is disposed between the tank and the salt container is subjected to negligible pressures, but is in contact with salt water which can cause incrustation phenomena at the movable members of the electrically operated valve itself.

As is known in fact, virtually all the part of the water supply circuit disposed downstream of the metering tank is involved with salt water, so that an electrically operated valve disposed at any point whatever in that part of the circuit scarcely turns out to be reliable.

According to the invention, there is provided an automatic washing machine comprising: a washing tub; at least one pump: and a water supply circuit comprising a controlled inlet valve, a free air gap portion and a decalcifier, a salt container having an outlet connected to the decalcifier and an inlet connected to a tank for metering of the decalcifier regeneration water, the tank communicating in its upper portion with the outside ambient atmosphere and with said air gap portion, and a closure member controlled, in use, by said pump for at least partially closing said circuit in a phase of the operating cycle of the machine, preceding regeneration of the decalcifier, in which the inlet valve is open.

The washing machine according to the invention therefore does not require any electrically operated valve, either upstream or downstream of the metering tank, for controlling the decalcifier regeneration phase. Filling of the tank and the regeneration phase are controlled by a simple closure member which can be of a material not substantially influenced by contact with salt water, thereby imparting a high degree of reliability to the entire water circuit of the machine.

The features and advantages of the invention will be more clearly apparent from the following description, given by way solely of non-limiting example, with reference to the accompanying drawings in which: Figure 1 is a diagrammatic view of the water supply circuit of a preferred embodiment of washing machine according to the invention, Figures 2 and 3 show a detail, on an enlarged scale, of the circuit of Figure 1, in two respective operating positions.

Referring to Figure 1, the washing machine comprises a supply conduit 9 for connecting the water main to the washing tub 4 of the machine by way of the series circuit of an electrically operated inlet valve 5, a free air gap portion 6 and a decalcifier 11.

In the case for example of a dish washing machine, the conduit 9 terminates within the tub 4 with an extension portion 7 (Figures 2 and 3) which can be designed as described in European patent application No. 80102829.1 in the name of the present applicants.

In particular, the upper end of the extension portion 7 is partially inserted into a bell member 10; for greater ease of comprehension of the structural and functional details of the members 7 and 10, reference should be made to the abovementioned patent application.

The supply circuit of the washing machine further comprises a salt container 12 having an outlet connected to the decalcifier 11 by way of a non-return valve 13, and an inlet connected by way of a conduit 14 to the bottom of a metering tank 8.

In substance, the tank 8 may be for example of the type described in Italian patent application No. 34036 B/79, filed on 15th November 1979, in the name of the present applicants (British Patent Application 8035760). In particular, the tank 8 communicates in its upper portion with the air gap portion 6 of the supply conduit and, by way of a connecting conduit 15 and an aperture 16 therein, with the ambient outside atmosphere. The aperture 16 is also connected to the washing tub 4, for the discharge of vapours.

The metering tank comprises, preferably integrally therewith, a small basin 17 communicating in its upper part with the remainder of the metering tank and disposed below the air gap portion 6, for collecting therefrom the normal water losses. The bottom of the basin 17 communicates with the conduit 15 and thus with the tub 4 by way of a calibrated hole 18 having a flow capacity substantially corresponding to the above-mentioned losses from the air gap portion 6.

The supply conduit 9 is provided, preferably downstream of the connection between the decalcifier 11 and the salt container 12, with a closure member 19 which is capable of being actuated by a pump 20 of the machine. In the case of a dish washing machine, the closure member may equally well be actuated by the discharge pump or by the circulating pump, while in the case of a clothes washing machine, it is obviously actuated by the discharge pump.

As shown in Figure 1, the closure member 19 is preferably disposed in line with the extension portion 7 of the supply conduit, within the washing tub.

For example, the closure member may comprise a resilient bellows-type member which is fixed to the bell member 10 above the distribution mouth opening of the extension portion 7.

The bellows assembly defines a closed chamber connected to the discharge of the pump 20 by way of a suitable opening in the bell member 10 and a control tube 21. When the pump is switched off, the closure member 19 is in the normal position shown in Figure 2 in which it permits the supply water to be discharged from the extension portion 7 of the conduit 9. When the pump 20 is in operation, the closure member 19 is caused to expand resiliently against the discharge mouth opening of the extension portion 7, as shown in Figure 3, thereby at least partially closing the supply conduit 9.

The pump 20 is actuated by the programmer (not shown) of the machine for a suitable period of time during a phase, immediately preceding regeneration of the decalcifier 11, in which the electrically operated inlet valve 5 is controlled to an open position; the design of this arrangement is within the capability of a man skilled in the art.

In operation, when the electrically operated valve 5 is open to pass water into the tub 4 by way of the decalcifier 11 , the pump 20 is switched off and the water losses from the portion 6 are completely collected by the basin 17 and conveyed into the tub by way of the calibrated hole 18 and the conduit 1 5, whereby the tank 8 remains empty. As already stated, before the regeneration phase, the electrically operated valve 5 is opened and the pump 20 comes into operation, causing the conduit 9 to be closed by the closure member 19. Consequently, substantially all the water from the water main overflows from the air gap portion 6 into the basin 17, with a flow rate which is substantially higher than that of the hole 18.The water thus rapidly overflows from the basin 17, filling the metering tank 8; any excess water that may be present overflows into the tub 4 by way of the conduit 15.

After a certain period of time, the electrically operated valve 5 is closed and the pump 20 is switched off, whereby the closure member 19 returns resiliently to the position shown in Figure 2. At that point, the decalcifier regeneration phase beings; the water collected in the tank 8 flows under the effect of gravity through the salt container 12, the valve 13 and decalcifier 11 , and passes into the washing tub 4.

It will be appreciated that the above-described washing machine can be modified in many ways, excepting the particular features claimed hereinafter.

For example, the closure member 19 could be of the normally closed type; in that case, the pump 20 will be actuated to open the closure member whenever the electrically operated valve 5 is opened, except during the phase of filling the metering tank 8, before regeneration of the decalcifier 11. In addition, the pump 20 will be actuated to perform the actual regeneration operation.

Claims (6)

1. An automatic washing machine comprising: a washing tub; at least one pump: and a water supply circuit comprising a controlled inlet valve, a free air gap portion and a decalcifier, a salt container having an outlet connected to the decalcifier and an inlet connected to a tank for metering of the decalcifier regeneration water, the tank communicating in its upper portion with the outside ambient atmosphere and with said air gap portion, and a closed member controlled, in use, hy said pump for at least partially closing said circuit in a phase of the operating cycle of the machine, preceding regeneration of the decalcifier, in which the inlet valve is open.

2. A washing machine according to claim 1 wherein said closure member is disposed in the supply circuit downstream of the connection of the decalcifier to the salt container.

3. A washing machine according to claim 1 or 2 wherein said closure member comprises a resilient bellows-type member defining a closed chamber connected to the discharge of said pump, the bellows-type member being capable of being actuated between a normal open position and an expanded position of at least partially closing said supply circuit.

4. A washing machine according to claim 1,2 or 3 wherein the supply circuit terminates with an extension portion which extends into the tub of the machine, the closure member being disposed in operative association with said extension portion.

5. A washing machine according to any one of the preceding claims wherein the metering tank is normally supplied with the water losses which occur at said air gap portion, and the tank comprises a basin which communicates in its upper portion with the remainder of the tank and which is capable of collecting said water losses and which is provided at the bottom with a hole connected to the washing tub and calibrated at a flow capacity substantially corresponding to said losses.

6. A washing machine constructed and arranged to operate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.