GB2106974A

GB2106974A - Door seal

Info

Publication number: GB2106974A
Application number: GB08228483A
Authority: GB
Inventors: Michael Brett
Original assignee: SILICONE ALTIMEX Ltd
Current assignee: SILICONE ALTIMEX Ltd
Priority date: 1981-10-06
Filing date: 1982-10-06
Publication date: 1983-04-20
Also published as: GB2106974B

Abstract

A seal for use in sealing between the surround to an opening, for example of an oven, and a door for closing the opening, comprises a continuous loop (4) of an elastomeric material such as a silicone rubber, provided with a plurality of anchorage members (8), preferably one at each corner of the opening, for securing the seal to a surface of the door or the surround. The size of the loop and the positioning of the anchorage members (8) within the loop is such, in relation to the opening to be sealed, that the seal, in use, is stretched between the anchorage members. The loop (4) is preferably formed from an extruded strip, the ends of which are bonded together, having a hollow portion (6) within which supporting arms (20) of the anchorage member (8) are bonded. This helps to shape the seal correctly at the corners. <IMAGE>

Description

SPECIFICATION Door seal This invention is concerned with a door seal.

The seal of the invention is particularly suitable for use with domestic and industrial oven doors.

Typically, a seal is located between the door and a face against which the door is closing, and is of a material which is resistant to the heat likely to be encountered by the oven. An especially suitable material for the seal is a silicone rubber material, but hitherto problems have arisen in locating the seal around the opening to be closed by the door, so as to ensure a firm uniform seal when the door is closed.

The present invention provides a seal for use in sealing between the surround to an opening and a door for closing the opening, the seal comprising a continuous loop of an elastomeric material provided with a plurality of anchorage members for securing the seal to a surface of the door or the surround, the size of the loop and the positioning of the anchorage members therein being such, in relation to the opening to be sealed, that the seal, in use, is stretched between the anchorage members.

Preferably, where the opening is a regular or irregular polygon, typically a rectangle, each anchorage member is located at a position adjacent to the intersection between two adjacent sides of the opening.

The loop may be in the form of an extruded strip, for example of a silicone rubber, the ends of which are bonded together. The extruded strip may comprise a hollow portion in which a support portion on each anchorage member may be bonded. The support portion may be shaped so as to guide the strip around a curve. This enables the seal to conform to the shape of the opening without the need for special shaping or preforming of the seal at the corners.

As the seal is supported only at the corners, fewer mounting clips are required, permitting the use of the more expensive stainless steel anchorage members without increasing the overall cost of the seal. Further, installation of the seal is simplified, and the use of stainless steel avoids the danger of early failure of the seal due to corrosion of the mounting clips.

The extruded strip preferably comprises, in section, a hollow triangular portion which is deflected and compressed by closure of the door over the opening. Since the ends of the strip are bonded together, the air sealed within the hollow increases in pressure when the oven heats up, and this may serve to improve further the efficiency of the seal.

Reference is now made to the accompanying drawings, in which:~ Figure 1 is a perspective view of a door and oven opening; Figure 2 is an enlarged perspective view of a portion of the seal and oven opening as shown in Figure 1; Figure 3 is a cross-sectional view along the line A-A of Figure 2; Figure 4 is a rear view corresponding to Figure 2, before insertion of the anchorage clip; Figure 5 is a cross-sectional view of an alternative seal; Figure 6 is a perspective view of a second alternative construction according to the present invention; and Figure 7 is a view on the line B-B of Figure 6.

Referring first to Figure 1, a door 1 is adapted to close against an oven housing 2. The housing defines an opening 3 which is surrounded by a seal 4 against which the door closes to prevent egress of heat from the interior of the oven 3. The seal 4 comprises an extruded strip which has, in section, a hollow triangular wing portion 5 which is deflected and compressed by the door, a pair of diverging legs 7 which seal against the face of the housing 2, and a hollow part 6 between the wing portion 5 and legs 7.

An anchorage clip 8 includes two curved supporting arms 20 extending on each side of a hook 9. The supporting arms 20 are inserted into the hollow part 6, by cutting a slit in the inner wall 21 of the strip, and secured using a suitable room temperature vulcanising (RTV) adhesive. The hook 9 engages in an aperture 14 in the face of the oven surrounding the opening 3, the apertures 14 being provided adjacent each corner thereof. The arms 20 may include a strengthening rib 12 therein.

The seals described and illustrated with reference to Figures 1 and 4 are particularly suited for situations where the corners in the loop may be radiused. By a suitable choice of crosssectional shape of the strip and distribution of material thickness it is possible for the strip to create the desired radiused corner without substantial deflection or distortion of the wing portion 5. The strip is jointed in an end to end fashion along one of the straight sides to form a continuous loop. When the anchorage clips 8 are located in the apertures 14 the seal is stretched therebetween and so resiliently maintains the clips 8 in position.

The degree of switch imparted to the seals is chosen so as to exceed any relaxation caused by heat expansion of the seal during use. Due to the continuous nature of the seal and maintenance of shape at the corners of the loop a continuous seal is provided around the opening 3.

Figure 5 shows an alternative section of the strip, having a hollow circular section portion 40 in place of the wing portion 5. This section is preferred for certain applications, but requires cutting and rebonding to form satisfactory corners.

The seal illustrated in Figures 6 and 7 has right angled corners and is made up by mitre cutting the strip and then jointing together at the corners using adhesive to provide a continuous loop. In this embodiment the clips 10 also help to stabilise the joints at the corners.

It will be appreciated that the present invention provides a seal for an oven door which can be tailor-made to fit a particular shape and size of door, and is readily and easily inserted in place by the hooks 9 being inserted into apertures 14 at the corners of the door.

Claims

1. A seal for use in sealing between the surround to an opening and a door for closing the opening, the seal comprising a continuous loop of an elastomeric material provided with a plurality of anchorage members for securing the seal to a surface of the door or the surround, the size of the loop and the positioning of the anchorage members therein being such, in relation to the opening to be sealed, that the seal, in use, is stretched between the anchorage members.

2. A seal according to Claim 1, wherein the opening is a regular or irregular polygon and each anchorage member is located at a position adjacent to the intersection between two adjacent sides of the opening.

3. A seal according to Claim 2, wherein each anchorage member comprises a pair of arms which extend within the seal, one arm on each side of the anchorage members, to support the elastomeric material at the intersection.

4. A seal according to any preceding claim, wherein the loop is in the form of an extruded strip, the ends of which are bonded together.

5. A seal according to Claim 4, wherein the extruded strip comprises a hollow portion and each anchorage member comprises a support portion which is bonded within the hollow portion.

6. A seal according to Claim 5, wherein the support portion serves to guide the strip around a curve, thereby enabling the seal generally to conform to the shape of the opening.

7. A seal according to Claim 4, 5 or 6, wherein the extruded strip comprises, in section, a hollow triangular portion which is deflected and compressed by closure of the door over the opening.

8. A seal according to any preceding claim, wherein the anchorage members each comprise a hook engageable in an aperture provided in the surface of the door or the surround.

9. A seal according to any preceding claim, wherein the anchorage members are formed from stainless steel.

10. A seal, substantially as described herein with reference to, or as shown in, the drawings.