GB2135158A

GB2135158A - Heating equipment

Info

Publication number: GB2135158A
Application number: GB08401244A
Authority: GB
Inventors: Ulrich Deiss; Heinz Riemath
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-02-03
Filing date: 1984-01-18
Publication date: 1984-08-22
Also published as: GB2135158B; FR2540374A1; IT8419300A0; FR2540374B1; GB8401244D0; DE3303682C2; DE3303682A1; IT1173126B

Abstract

A coupling device for a temperature sensor and an electrical heating element serves to provide thermostatic protection of combined electrical water and air heating in a dishwashing or laundry treatment machine. The device is constructed as a bridge and consists of a ceramic spacer member (10), which comprises a plate (13) engaging over a cap (7) of the sensor (6), the cap being arranged between two length portions (4, 5) of the heating element. At its underside the plate (13) has webs (14, 15), which screen the cap (7) laterally at a certain spacing from the heating element portions (4, 5). <IMAGE>

Description

SPECIFICATION Heating equipment The present invention relates to heating equipment for a dishwashing or laundry drying orwashing machine, and has particular reference to fastening means for a temperature sensor and an electric heating element.

In a known fastening device for this purpose (DE-GM 80 180), the device comprises a bridge having an arm which wedges a tubular heating element through an oblique plane directly against a measuring surface of a temperature sensor in such a manner that the oblique plane of the arm and the measuring surface of the sensor form a gap which narrows in the direction of expansion determined by the increasing heating-up of the element. As a result, the heater element is pressed increasingly firmly against the sensor with increasing change of shape of the heater element. The arm forming the bridge is screwed against a base of a rinsing container of an appliance.

There is, however, scope for an improved fastening device to make possible a temperature sensor and heating element installation in dishwashing machines and laundry treatment machines which have combined water and air heating.

According to the present invention, there is provided heating equipment for a dishwashing or laundry drying or washing machine, comprising a tubular electric heating element extending in a heating chamber, a temperature sensor comprising a sensing head projecting into the chamber to extend between two length portions of the element, and a bridge member which is of a material of low thermal conductivity and which holds the two element portions in thermally conductive contact with the sensing head, the bridge member comprising a plate portion engaging over a free end portion of the sensing head and web means extending from the plate portion and between the sensing head and the two element portions to space and screen the head from the element portions.

With equipment embodying the present invention, the heating can be protected by a thermostat or sensor in a dishwashing machine in economical programs devolving with low water level in the rinsing container. The web means of the bridge member so screen the sensor from the element arranged on either side of the sensor that an overheating protection through heat radiation is formed in the program section "air heating", for example during the drying of dishes or laundry, whilst in the program section "water heating" for the heating-up of rinsing or washing liquid it is possible to prevent the sensor from prematurely switching off the heating due to heat radiation or to an overheated partial quantity of water.

Preferably, the sensing head is provided with a securing tab which extends through an opening in the plate portion and is bent to secure the bridge member to the sensing head. This has the advantage that mounting of the bridge member does not necessitate an additional opening in, for example, wall means of a rinsing container bottom and a seal for such an opening. The bridge member additionally protects the sensor against loosening in its own mount, which is, for example, by way of sealing means in the wall means.

For preference the plate portion extends beyond the web means and at least substantially halfway over each of the two element portions. This results in a simple fastening holding the sensor as well as the heater element portions in defined spacing relative to each other.

Expediently, the plate portion is provided at a side thereof remote from the sensing head with a troughlike depression. A certain quantity of water, which has a cooling effect on the bridge member, can collect in such trough-shaped depression.

Construction of the bridge member in ceramic is particularly advantageous for the desired heat transfer between the heating element and the temperature sensor.

An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Figure 1 is a vertical section through heating equipment embodying the invention; Figure 2 is a cross-section on the line Il-Il of Figure land Figure 3 is a plan view of the equipment.

Referring now to the drawings, there is shown heating equipment comprising a rod-shaped electric heating element 2 which is disposed in, for example, U-shape or loop shape over the base 1 of the rinsing container of a dishwashing or laundry treatment machine. The end portions of the element are combined in a flange 3 and are provided with connections leading outwardly through the rinsing container.

A temperature sensor 6 or thermostat is arranged between two portions 4 and 5 of the element 2. A cap 7 of the sensor projects through a passage 8 into the rinsing container, the sensor being fastened in the passage by means of a seal 9, which can be snapped into place. Provided for the mounting of the element portions 4 and Sat a defined spacing relative to the cap 7 of the sensor is a ceramic spacer member 10, which consists of a plate 13 covering over the end face of the cap as well as the element portions 4 and 5 approximately as far as the vertical centre planes 11 and 12, and two webs 14 and 15 projecting at the underside of the plate between the cap and the element portions.

For the protection of the sensor 6 against falling out of the seal 9 or the passage 8, and for mounting the member 10 on the sensor cap 7 and the element 2, a recess 16, through which a twistable fastening tab 17 of the temperature sensor is inserted, is provided in the plate 13. In addition, the plate 13 has a trough-shaped depression 18 on its upper side for collecting water to cool the member 10.

1. Heating equipment for a dishwashing or laundry drying or washing machine, comprising a tubu

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Heating equipment The present invention relates to heating equipment for a dishwashing or laundry drying orwashing machine, and has particular reference to fastening means for a temperature sensor and an electric heating element. In a known fastening device for this purpose (DE-GM 80 180), the device comprises a bridge having an arm which wedges a tubular heating element through an oblique plane directly against a measuring surface of a temperature sensor in such a manner that the oblique plane of the arm and the measuring surface of the sensor form a gap which narrows in the direction of expansion determined by the increasing heating-up of the element. As a result, the heater element is pressed increasingly firmly against the sensor with increasing change of shape of the heater element. The arm forming the bridge is screwed against a base of a rinsing container of an appliance. There is, however, scope for an improved fastening device to make possible a temperature sensor and heating element installation in dishwashing machines and laundry treatment machines which have combined water and air heating. According to the present invention, there is provided heating equipment for a dishwashing or laundry drying or washing machine, comprising a tubular electric heating element extending in a heating chamber, a temperature sensor comprising a sensing head projecting into the chamber to extend between two length portions of the element, and a bridge member which is of a material of low thermal conductivity and which holds the two element portions in thermally conductive contact with the sensing head, the bridge member comprising a plate portion engaging over a free end portion of the sensing head and web means extending from the plate portion and between the sensing head and the two element portions to space and screen the head from the element portions. With equipment embodying the present invention, the heating can be protected by a thermostat or sensor in a dishwashing machine in economical programs devolving with low water level in the rinsing container. The web means of the bridge member so screen the sensor from the element arranged on either side of the sensor that an overheating protection through heat radiation is formed in the program section "air heating", for example during the drying of dishes or laundry, whilst in the program section "water heating" for the heating-up of rinsing or washing liquid it is possible to prevent the sensor from prematurely switching off the heating due to heat radiation or to an overheated partial quantity of water. Preferably, the sensing head is provided with a securing tab which extends through an opening in the plate portion and is bent to secure the bridge member to the sensing head. This has the advantage that mounting of the bridge member does not necessitate an additional opening in, for example, wall means of a rinsing container bottom and a seal for such an opening. The bridge member additionally protects the sensor against loosening in its own mount, which is, for example, by way of sealing means in the wall means. For preference the plate portion extends beyond the web means and at least substantially halfway over each of the two element portions. This results in a simple fastening holding the sensor as well as the heater element portions in defined spacing relative to each other. Expediently, the plate portion is provided at a side thereof remote from the sensing head with a troughlike depression. A certain quantity of water, which has a cooling effect on the bridge member, can collect in such trough-shaped depression. Construction of the bridge member in ceramic is particularly advantageous for the desired heat transfer between the heating element and the temperature sensor. An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Figure 1 is a vertical section through heating equipment embodying the invention; Figure 2 is a cross-section on the line Il-Il of Figure land Figure 3 is a plan view of the equipment. Referring now to the drawings, there is shown heating equipment comprising a rod-shaped electric heating element 2 which is disposed in, for example, U-shape or loop shape over the base 1 of the rinsing container of a dishwashing or laundry treatment machine. The end portions of the element are combined in a flange 3 and are provided with connections leading outwardly through the rinsing container. A temperature sensor 6 or thermostat is arranged between two portions 4 and 5 of the element 2. A cap 7 of the sensor projects through a passage 8 into the rinsing container, the sensor being fastened in the passage by means of a seal 9, which can be snapped into place. Provided for the mounting of the element portions 4 and Sat a defined spacing relative to the cap 7 of the sensor is a ceramic spacer member 10, which consists of a plate 13 covering over the end face of the cap as well as the element portions 4 and 5 approximately as far as the vertical centre planes 11 and 12, and two webs 14 and 15 projecting at the underside of the plate between the cap and the element portions. For the protection of the sensor 6 against falling out of the seal 9 or the passage 8, and for mounting the member 10 on the sensor cap 7 and the element 2, a recess 16, through which a twistable fastening tab 17 of the temperature sensor is inserted, is provided in the plate 13. In addition, the plate 13 has a trough-shaped depression 18 on its upper side for collecting water to cool the member 10. CLAIMS

1. Heating equipment for a dishwashing or laundry drying or washing machine, comprising a tubu lar electric heating element extending in a heating chamber, a temperature sensor comprising a sensing head projecting into the chamber to extend between two length portions of the element, and a bridge member which is of a material of low thermal conductivity and which holds the two element portions in thermally conductive contact with the sensing head, the bridge member comprising a plate portion engaging over a free end portion of the sensing head and web means extending from the plate portion and between the sensing head and the two element portions to space and screen the head from the element portions.

2. Equipment as claimed in claim 1, wherein the sensor is mounted in wall means of the chamber by eay of sealing means.

3. Equipment as claimed in either claim 1 or claim 2, wherein the sensing head is provided with a securing tab which extends through an opening in the plate portion and is bent to secure the bridge member to the sensing head.

4. Equipment as claimed in any one of the preceding claims, wherein the plate portion extends beyond the web means and at least substantially halfway over each of the two element portions.

5. Equipment as claimed in any one of the preceding claims, wherein the plate portion is provided at a side thereof remote from the sensing head with a trough-like depression.

6. Equipment as claimed in any one of the preceding claims, wherein said material is a ceramic material.

6. Equipment as claimed in any one of the preceding material, wherein said material is a ceramic material.

7. Heating equipment substantially as hereinbefore described with reference to the accompanying drawings.

Superseded claims 1,3 and 6 New or amended claims:

1. Heating equipment for a dishwashing or laundry drying or washing machine, comprising a tubular electric heating element extending in a heating chamber, a temperature sensor comprising a sensing head projecting into the chamberto extend between two length portions of the element, and a holding-down member which is of a material of low thermal conductivity and which holds down the heating element and places the element in thermally conductive contact with the sensing head, the member being fastened to the sensing head and comprising a plate portion engaging over a free end portion of the sensing head and web means extending from the plate portion and between the sensing head and the two element portions to space and screen the head from the element portions.

3. Equipment as claimed in either claim 1 or claim 2, wherein the sensing head is provided with a securing tab which extends through an opening in the plate portion and is bent to secure the member to the sensing head.