GB2217110A

GB2217110A - Device for fixing thermostats

Info

Publication number: GB2217110A
Application number: GB8905922A
Authority: GB
Inventors: Luigi Arreghini
Original assignee: Industrie Zanussi SpA
Current assignee: Industrie Zanussi SpA
Priority date: 1988-03-29
Filing date: 1989-03-15
Publication date: 1989-10-18
Anticipated expiration: 2009-03-15
Also published as: FR2629630A3; IT8834015V0; DE8903227U1; ES1009600Y; ES1009600U; IT215689Z2; GB8905922D0; FR2629630B3; GB2217110B

Abstract

A fixing device for fitting a thermostatic sensor (5) in a water container (3) of a clothes washing machine provided with at least one electrical heating element (4) is disclosed. The sensor (5) is provided with at least one bulb (6) which is sensitive to the temperature of the water in the container (3) and which is enclosed by a metal casing (7) provided with zone (8) of enlarged cross section, and a portion (9) of insulating material which is introduced into the metal casing and which encloses at least one electrical switch which can be connected to the heating element (4) and which can be actuated to close or open in dependence on the temperature detected by the bulb. Resilient engagement means (15, 16) are provided in association with a through hole (13) passing through the wall of the container (3), and engage against the enlarged zone (8) of the sensor when the bulb is introduced through the through hole (13) with the interposition of at least one seal (12). The seal (12) bears against and is compressed against a seat (14) provided in the interior of the through hole (13). <IMAGE>

Description

DEVICE FOR FIXING SENSOR ELEMENTS SUCH AS THERMOSTATS OR THE LIKE The invention relates to a device of simple type for permitting rapid and secure fixing of sensor elements such as thermostats or the like in the appropriate position of use thereof in electrical domestic appliances.

To provide for thermostatic control of the temperature of the water contained in heated containers such as for example clothes washing machine drums, suitable thermostatic sensors are normally employed, comprising a suitably shaped bulb and an electrical switch which can be actuated at a predetermined control temperature by thermal expansion of a liquid contained in the bulb, the switch being connected to at least one electrical heating element for heating the water and being operable to switch the heating element on and off repeatedly, thereby to produce the predetermined heating temperature for the water.

In particular, such thermostatic sensors are fitted in -posit-.on using a sealing gasket which is introduced through a corresponding hole provided in the wall of the tub of the clothes washing machine, and then introducing the sensors themselves through corresponding openings provided in the seal, in such a way that each sensor is fixed in the associated seal, possibly also using suitable adhesives, in the condition in which the bulb remains in contact with the water contained in the tub while the electrical contacts of the sensor are disposed on the outside of the tub, to be connected by way of conventional electrical connectors to the associated heating element of the machine.While operating in a satisfactory and reliable fashion, thermostatic sensors which are fixed in position in that way do however require the use of suitable shaped seals for fitting the sensors themselves, and a series of complicated operations which are impractical in use for fitting the seals and the sensors in the associated tubs of clothes washing machines.

Therefore, the aim of the present invention is to overcome the above-described disadvantages by means of a fixing device of a simple kind, which is suitable for providing for quick and secure fixing of the thermostatic sensors in the appropriate position of use.

According to the present invention, there is provided a fixing device for fitting in position a thermostatic sensor for a washing machine, said sensor being capable of controlling the heating temperature of the water contained in a container provided with at least one electrical heating element and being provided with at least one bulb which is sensitive to the temperature of the water and which is enclosed by a casing provided with a zone at one end of the bulb which is of enlarged cross section, and a portion of insulating material which extends into said casing and which encloses at least one electrical switch which can be connected to said heating element and which can be actuated to close or open in dependence on the temperature detected by said bulb, resilient engagement means provided in association with a through hole passing through the wall of said container, said engagement means being capable of engaging against said enlarged terminal zone of said sensor when said bulb is introduced through said through hole with the interposition of at least one seal.

The features of the invention will be more clearly apparent from the following description which is given solely by way of non-limiting example and with reference to the accompanying drawings in which: Figure 1 is a view in longitudinal section of part of a container for the water for a clothes washing machine, the container being provided with the fixing device according to the invention, and Figure 2 is a plan view of the container shown in figure 1, incorporating the present fixing device.

Referring to the drawings, shown therein is a container 3 for containing the water for a clothes washing machine, the container preferably being of a box-like shape and being arranged to contain at least one electrical water heating element 4 which is operatively connected into the electrical circuit of the machine.

The container in particular is produced separately and is connected in per se known manner to the lower part and the upper part and also to the discharge of the clothes washing machine thereby to provide a clothes washing machine with a washing liquid recirculating system, like that described for example in European patent number 0146719 filed on 24 October 1984 by Industrie Zanussi SpA.

In order to be able to control the temperature to which the water in the container 3 is heated, the machine uses a conventional thermostatic sensor 5 which can be mounted in the container, using the means described hereinafter.

The thermostatic sensor comprises a bulb 6 of cylindrical shape, which is responsive to the water temperature and which is enclosed by a corresponding metal casing 7 provided with an enlarged terminal zone 8 of circular shape, and a portion 9 of insulating material which is introduced into the metal casing 7 and which encloses at least one electrical switch (not shown), the terminals 10 and 11 of which can be connected by way of conventional connectors (not shown) to the electrical heating element 4, the switch being actuable to close or open in dependence on the temperature detected by the bulb 6.

The thermostatic sensor 5 is disposed in the appropriate position of use by previously fitting a seal 12 of annular shape over the bulb 6 of the sensor, and then introducing the bulb 6 into a corresponding through hole 13 which passes through the wall of the container 3, in such a way that the seal comes to bear and is compressed against a circular seat 14 provided in the interior of the hole 13, thus ensuring that the hole is sealingly closed.

To ensure that the thermostatic sensor 5 is fixed in position, the present fixing device is further provided with a pair of resilient engagement tongues 15 which are provided in one piece in the wall of the container 3 at a position corresponding to the through hole 13 and in mutually diametrally opposite positions, wherein the tongues can be spread apart to permit the thermostatic sensor 5 to pass therebetween, and the tongues each being provided with a respective tooth 16 engageable against the corresponding enlarged terminal zone 8 of the sensor when the sensor is introduced into the hole 13 in the above-described manner.

Consequently, by virtue of using the present fixing device which is of a simple nature and which is convenient to use, it is possible to provide for quick and secure fixing of the thermostatic sensor in the appropriate position of use thereof, in which only the bulb 6 of the sensor is in contact with the water contained in the container 3 for thermostatic control of the heating temperature thereof, while the insulating portion 9 of the sensor is disposed outside the container, whereby the terminals 10 and 11 of the switch can be connected to the electrical heating element 4.

It will be appreciated that the thermostatic sensor may also be fixed in position by providing tongues or further engagement elements which are shaped differently from the above-mentioned tongues, with the option of using one or more locking screws 17 which can bear against the enlarged terminal zone 8 of the sensor and which can be screwed into and unscrewed from corresponding screwthreaded holes 18 which are also integrally provided in the wall of the container 3 (see figure 2).

Claims

1. A fixing device for fitting in position a thermostatic sensor for a washing machine, said sensor being capable of controlling the heating temperature of the water contained in a container provided with at least one electrical heating element and being provided with at least one bulb which is sensitive to the temperature of the water and which is enclosed by a casing provided with a zone at one end of the bulb which is of enlarged cross section, and a portion of insulating material which extends into said casing and which encloses at least one electrical switch which can be connected to said heating element and which can be actuated to close or open in dependence. on the temperature detected by said bulb, resilient engagement means provided in association with a through hole passing through the wall of said container, said engagement means being capable of engaging against said enlarged terminal zone of said sensor when said bulb is introduced through said through hole with the interposition of at least one seal.

2. A fixing device according to claim 1 wherein said seal is capable of bearing against and is compressed against a seat provided in the interior of said through hole.

3. A fixing device according to claim 1 wherein screws or the like are provided, which engage against said enlarged terminal zone and which can be screwed into and unscrewed from corresponding screwthreaded holes in said container.

4. A fixing device constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

5. A washing machine having a sensor fixed therein by the device of any one of the preceding claims.

6. A washing machine according to claim 5 and which is a clothes washing machine.