GB2099988A - Composite panel structures e.g. oven doors - Google Patents

Abstract

A panel structure suitable for oven doors of cookers comprises two sheet metal panels 1,2 each with a peripheral flange 3,4. The panels are detachably secured together in nested relationship with the flanges in close proximity by means of releasable fasteners of unitary form passed through aligned apertures 10,12 in the flanges. The fasteners have first and second surfaces that engage respectively the flanges 3,4 on the members and draw the flanges together when the fasteners are in position. <IMAGE>

Description

SPECIFICATION Improvements in or relating to composite panel structures This invention relates to composite panel structures and has particular although not exclusive reference to such structures adapted to act as doors. The invention has especial application to the doors for cooking appliances, for example to oven doors.

Many oven doors are made up from sheet metal panels with peripheral flanges, the panels being nested together in spaced relationship with the flanges on a panel locating in close proximity to those on the other panel. Metal strips secured to the inside face of one of the panels impart a degree of rigidity to the assembly. The panels are secured together by screws passed through holes in one panel adjacent the periphery thereof and screwed into brackets secured to the inner face of the other panel.

Such a construction has many component parts and is consequently expensive to produce and assemble.

According to the present invention, a composite panel structure comprises first and second panel members each with a peripheral flange, the flanges being apertured at spaced locations round the members, and in which the panel members are held together by releasable fasteners of unitary form passed through the holes, each fastener having a first and second surface that engage respectively the flange on the first member and the flange on the second member in such mannerthatwhen the fastener is in position, the surfaces draw the flanges together and hold them.

Each panel member may be generally planar, the flanges extending in a direction generally at right angles to the plane of the panel.

The panel members may be nested together in spaced relationship with the flanges in close proximity one with the other.

When embedded in a door, there may be a door latch located between the panels one of which is apertured adjacent the latch in such manner as to permit the latch to engage a door catch.

By way of example only, an oven door embodying the invention will now be described in greater detail with reference to the accompanying drawings of which Figure 1 is a rear view of the door, Figure 2 is a perspective view of a corner of the door showing parts thereof in a separated orientation, Figure 3 is a section through a part of the door, and Figures 4, 5and 6 are, respectively, rear view, first side view and second side view of a component.

The door is of composite panel construction being made up of an inner panel 1 which forms the inside face of the door, and an outer panel 2 which forms the outside face of the door.

The panels are of generally rectangular shape when seen in elevation as in Figure 1 and each panel 1,2 is of generally planarform and has a peripheral flange 3, 4 respectively extending at right angles to the panel. Both flanges are continuous, that 4, on panel 2, being of constant height throughout its length, whilst that 3 on panel 1 is cut away, as indicated at 5, at each corner.

The face of panel 1 is formed with a raised wall 6 separated from the edge of the panel by a flat surface 7. Within the raised wall 6 the panel 1 is "dished" inwardly slightly towards a central flat area 8. The formation of the wall 6 and the inward dishing imparts a degree of rigidity to the panel. The flange 3 is formed with surfaces 9 that are raised slightly above the surface of the remainder of the flange.

There are four such surfaces 9, each being located adjacent a corner at the top and bottom of the door.

The positions are indicated diagrammatically in Figure 1 and referenced 9. Each surface 9 has a square hole 10 positioned approximately centrally of the surface.

On the flat surface 7 at each corner of the panel is a group 11 of three holes of semi-circular shape orientated as shown on a larger scale in Figure 2.

The face of panel 2 is plane, and formed in the flange 4, in positions aligned with the holes 10 in the flange 3, are square holes 12.

To assemble the door, the panels 1, 2 are nested together, the flange 3 on panel 1 being located inwardly with respect to flange 4 on panel 2 and lying closely adjacent thereto, the surfaces 9 being in contact with the inside face of the flange 4. The panels are disposed in spaced relationship and are then secured together by removable fasteners entered through the holes 12 and 10. The fasteners are of a resilient material, for example a plastics material and are of a configuration such that when in position the surfaces 9 are pressed against the adjacent inside face of the flange 4.

Sealing strips to reduce the escape of hot air and cooking fumes from between the door and its frame are normally fitted to the surface 7. Such strips may comprise, as shown in Figure 2, a core comprising a metal strip 13 round which is wrapped a jacket 14 of a resilient heat resisting material - for example a silicone rubber. The ends of the metal strip project from each end of the jacket and are used to locate the sealing strip on the surface 7 by inserting the ends of the metal strip in the appropriate one of the group of holes 11. In the case of the strip shown in Figure 2, the ends of the metal strip are inserted into the centre hole 15 of the group 11 of the holes.

The remaining holes in the group 11 are used to locate and hold the end of the metal core of an adjacent sealing strip, these holes providing alternate locations depending upon the orientation of the door.

It is, of course, to be understood that the door described above may be hinged to a door frame in any suitable manner. The door may be hinged along one vertical edge or it may be a drop-down door in which case it is mounted along its lower edge.

The door shown in Figure 1 has apertures 26, 27 for the reception of door restraints, the door being suitable for hinges either on its right- or left-hand side. To change from right- to left-hand hinging the door is simply turned through 180 . Such a change in orientation requires a change in the arrangement of the sealing strips because they are fixed along the top and sides only of the door.

Additionally, a latching mechanism and a door knob are normally fitted to the door to enable a user to open and shut the door easily and to hold the door shut when required.

Conveniently, a latching mechanism is concealed between the two panels being secured to one or the other and being operable by a door handle mounted upon the outer panel 2. A door catch fitted to the door frame has access to the latching mechanism via an aperture in panel 1. Apertures 24 and 25 are shown in Figure 1,the latching mechanism being located behind one or other of these depending upon the location of the catch.

As has been explained above, the fasteners holding the panels together are removable so that, in the event that it becomes necessary to repair or replace the latching mechanism, ready access to the latter can be obtained merely by removing the fasteners and separating the panels.

The releasable fasteners may be of any suitable form but preferably they are of a configuration such that after insertion through the holes 12 and 10 a turn or partial turn of the fastener serves both to lock the latter in position and to draw the flanges 3 and 4 together.

One suitable form of fasteners is shown in Figures 4, 5 and 6. It is of a one-piece construction of moulded nylon. On the rearface of a slightly domed head 16 is formed a slightly raised area 17 of square shape when seen in plan. Extending from the raised area 17 is the stem 18 of the fastener, this also being of square shape when seen in plan as in Figure 4 but rotated through 45 with respect to area 17. The end face 19 of the stem is bevelled as at 20 and because of the orientation of the stem relative to the surface 17, the stem has four inclined faces of which three referenced 21 can be seen in Figure 5. Edges of two of the faces 21 are referenced 22 in Figure 6.

To use the fastener, the stem is passed through the hole 12 in flange 4 of panel 2 and through hole 10 in flange 3 of panel 1. The positions of the flanges 3, 4 are then as shown in Figure 6.

By means of a diametral slot 23 in the head 16, the fastener is then rotated through 45 . As the fastener rotates, the inclined faces 21 contact the inner face of flange 3 and urge the flange into close contact with flange 4, the two flanges being "squeezed" between the head 16 and the faces 21. At the same time, surface 17 moves out of alignment with hole 10, the two flanges then being locked together between surface 17 and surfaces 21,the "squeeze" action being assisted by a degree of resiliency in the fastener itself. This position is shown in Figure 5.

To remove the fastener should this become necessary, a rotation of 45" allows the fastener to be withdrawn.

When used as an oven door, the space between the panels 1,2 contains a thermally insulating material for example glass wool, or a sheet of aluminium foil.

The invention can be used in the construction of other doors than oven doors, for example, it may be embodied in doors for hot cupboards.

Additionally, the invention may be used in the construction of composite panel structures used as partition walls. In such cases, the panels employed may have peripheral flanges of forms other than that described above, for example, the flanges may include an outwardly directed surface in which the holes corresponding with the holes 10 and 12 mentioned above are formed.

The raised surfaces 9 described above are particularly advantageous when the panels are of vitreous enamelled sheet metal because they reduce the possibility of damage to the enamel coating caused by flexing of the flange which might otherwise occur when the fasteners are placed in position. However, such surfaces are not essential in constructions not requiring vitreous enamelled panels.

Claims (6)

1. A composite panel structure comprising first and second panel members each with a peripheral flange, the flanges being apertured at spaced locations round the members, and in which the panel members are held together by releasable fasteners of unitary form passed through the apertures, each fastener having a first and second surface that engage respectively the flange on the first member and the flange on the second member in such manner that when the fastener is in position, the surfaces draw the flanges together and hold them.

2. A composite panel structure as claimed in claim 1 in which each panel member is generally planar and in which the flanges extend in a direction generally at right angles to the plane of the panel member.

3. A composite panel structure as claimed in claim 2 in which the panel members nest together in spaced relationship with the flanges in close proximity one with the other.

4. A door structure as claimed in any one of the preceding claims in which a door latch is located between the panel members one of which is apertured adjacentthe latch in such manner as to permit the latch to engage a door catch.

5. A door structure substantially as herein described with reference to and as illustrated by the accompanying drawings.

6. A cooker having an oven door of the composite panel construction as claimed in any one of the preceding claims.