GB2172389A - Oven luminaire - Google Patents

Abstract

An oven luminaire has an insulating base (1) to which is attached a socket (2) for detachably receiving a screwthreaded cover which will cover a lamp bulb fitted to the base, wherein the socket is formed as a stamped and bent part comprising a collar (3) which has angularly spaced depending lugs (5) which have inwardly bent end portions disposed on a helix, thereby to enable fitting of the screwthreaded cover. <IMAGE>

Description

SPECIFICATION Oven Luminaire Field of the Invention The present invention relates to an oven light fitting or luminaire comprising a base part made from insulating material for receiving electric contacts and a lamp, a metal socket for anchoring the luminaire in a wall of the oven or the like and a glass cover connectable to the socket.

Priorart In a known arrangement, the socket is frontally provided with a collar and with radially outwardly projecting fastening elements and is optionally connectable by means of cut sheet metal lugs to a socket base, whilst the socket is also internally provided with a screw-in thread for the threaded end portion of the glass cover.

On the basis of this prior art, the problem of the invention is to provide an improved oven luminaire which can be manufactured particularly inexpensively and which ensures an excellent dissipation of the heat produced by the lamp.

The invention According to the invention, there is provided an oven luminaire comprising: an insulating base for carrying electric contacts and for receiving a lamp, a socket secured to the base and for anchoring the luminaire to the oven wall, and a transparent cover detachably connected to the socket, wherein the socket is formed as an element stamped and bent from sheet metal which includes an annular collar from which depend angularly spaced lugs extending first downwardly towards the base and second are bent with end portions extending radially inwards, said end portions lying on a helix to enable a screwthreaded collar to be detachably screwed thereto.

Thus, the aforesaid problem is solved in that the socket is constructed as a stamped/bent part, whose annular, substantially flat collar has as fastening elements, optionally cut first lugs bent at least roughly at right angles from the ring plane, in that the collar has between said first lugs further cut second lugs bent at least approximately at right angles from the ring plane and whose ends are bent at least one further time radially inwards and approximately at right angles. These bent ends have a level-differing spacing from the ring plane. The ends are arranged on an imaginary helix, whose pitch corresponds to the thread pitch of the glass cover and consequently the ends form the screw-in thread.

An important advantage of this oven luminaire is that the socket is constructed as a stamped/bent part and is consequently not deep drawn. As a result, the socket can be stamped from a flat sheet metal strip and can subsequently be bent with a simple bending device.

As a result of this construction, the socket body, with the exception of the bent lugs, is completely open, so that the heat produced by the lamp can be easily and largely dissipated.

Another important measure is that the screw-in thread for the glass cover is formed by the second lugs, so that on the one hand the glass cover is reliably secured and on the other a particularly inexpensive manufacture is permitted.

According to a further development, the invention proposes the construction of the first lugs as stop springs which are each freely cut towards the collar at least approximately parallel to the edges of the particular lug and are bent radially outwards in an approximately V-shaped manner.

Due to the fact that the stop springs are cut on said first lugs, which act as fastening elements, an advantageous stiffening of the springs is obtained, because they are rigidly connected via the end of the fastening element to the base, leading to the high degree of stiffness.

The construction as a stamped/bent part permits a suitable material selection, because attention no longer has to be paid to deep drawing processes and the like. The special arrangement of stop springs also permits a favourable material selection, because the starting material for the socket can have limited springiness due to the constructionally created stiffness of the springs.

It is particularly easy to fix the socket to the corresponding oven wall in the recess provided as a result of the stop springs, so that there is no need for additional connecting means, such as screws or the like. Atolerance compensation is also possible, which represents an important advantage compared with bayonet-type locking.

It is advantageously further proposed that the socket base has a radially extending collar with axial engagement slots for the free ends of the first lugs, said ends passing through the said slots and being bent to the rear of the collar. Thus, the collar can be connected very simply to the socket base.

Between the socket base and the collar a space is provided, which is only partly covered by the bent lugs, so that a good dissipation of the lug heat is permitted.

According to a further development, four first lugs are uniformly distributed round the circumference of the collar and in each case two second lugs are formed betwen two adjacent first lugs. This ensures a very reliable mounting and an adequately secure mounting of the glass cover in the thread-forming lugs. Preferably, the collar is curved in approximately V-shaped manner.

This once again permits a good tolerance compensation in the case of the conventionally enamelled metal sheets of the oven wall. Entry of the sheet between the edge of the stop spring and the collar is largely prevented, because the collar is bent over in roughly V-shaped manner in such a way that, between the upper spring edge and the collar, only a very small gap is left. The outer edge of the collar can be bent outwards, so that no sharp edge is formed towards the oven wall.

According to a further development, it is proposed that the first lugs between the bending line of the stop springs and the end portions insertable in the engagement slots are offset radially inwards. This provides an assembly aid and also improves the rigidity of the complete luminaire.

It is also advantageous for the end portions of the first lugs to have a projection in the vicinity of the walls of the engagement slots. This also leads to a stiffening and also ensures a certain prelocking during assembly, so that the support part can firstly be locked onto the socket base, before bending over the lugs and achieving the ultimate assembly positions.

In order to further improve the air circulation, it is proposed that the collar of the socket base is recessed in a radially spring-back manner in the area between the engagement slots.

To be able to fit an earthline to the socket, it is proposed that the collar has a further cut lug which is bent at right angles and whose free end is constructed as a plug. Preferably the lug constructed as a plug is arranged between two second lugs, whereof one forms the start of the thread.

Advantageously the two second lugs forming the start of the thread are narrower than the further second lugs. This leads to the most favourable arrangement of the plug, because it is now positioned with an adequate material cross-section between the lugs forming the two first thread portions, said lugs being narrower, so that the arrangement of the plug only leads to a slight weakening of the screw mounting at an unimportant point.

Advantageously the first lugs are constructed so as to taper in stepped manner towards the free end, the first taper being spaced from the bending edge of the stop spring, the second taper is located on the first bending edge of the offset and the third taper on the second bending edge of the offset. Advan tageouslythe base is made from plastics material.

Brief description of drawings An embodiment of the invention is described hereinafter with respect to the accompanying drawings, wherein: Figure 1 shows a baking oven luminaire, without the screwed-in glass cover, in plan view.

Figure 1 is in side view of the luminaire.

Figure 3 shows a metal blank.

Description of embodiment The oven luminaire essentially comprises a base 1 made of an insulating material and preferably of a plastics material, as well as a not shown lamp or bulb, which can be screwed into the base, a metal socket 2 for anchoring the luminaire in the wall recess of an oven orthe like, and a glass cover connectable to the socket 2. The socket is frontally provided with a collar 3 and radially outwardly projecting fastening elements and is optionally connectable via cut sheet metal lugs to a socket on the base 1. Socket 2 is constructed as a stamped/bent part, whose annular, substantially flat collar 3 has cut first lugs 4 bent at least approximately at right angles from the ring plane and which act as fastening elements.Between said first lugs 4, the collar 3 carries further cut second lugs 5, which are also bent at least approximately at right angles from the ring plane and whose ends are bent radially inwards and approximately at right angles at least once more.

These bent ends have a level-differing spacing from the ring plane and the ends are arranged on an imaginary helix, whose pitch corresponds to the thread pitch of the not shown glass cover, so that the ends form the screw-in thread. The first lugs 4 are constructed as stop springs 6 and are freely cut towards collar 3 and parallel to the edges of the particular lug 4 and are bent outwards radially in approximately V-shaped manner. They are used for locking the support part in the wall of an oven. The socket base has a radially extending collar7 with axial engagement slots 8 for the free ends of the first lugs 4. The ends pass through slots 8 and after assembly has taken place are bent to the rear of collar 7, as can be clearly gathered from the righthand side of Figure 2.

In the illustrated embodiment, four lugs 4 are uniformly distributed round the circumference of collar 3 and in each case two lugs 5 are cut between adjacent lugs 4. Collar 3 is curved inV-shaped manner and has a radially outwardly directed runout edge, so that damage to the oven wall can be avoided. Lugs 4 are radially inwardly offset between the bending line of stop spring 6 and the end portions insertable in engagement slots 8, which provides an assembly aid. Moreover, the end portions of lugs 4 are provided with a projection in the vicinity of the walls of the engagement slots 8, which permits a prefixing during assembly.

In order to improve the heat dissipation, the collar 7 of base 1 is recessed in radially spring-back manner in the area between the engagement slots 8, as can be seen from Figure 1.

On collar 3 is provided a further cut lug 9, which is bent at right angles and whose free end is constructed as a plug. Lug 9 is arranged between two lugs 5, whereof one forms the start of the thread. The lug 9 forming the start of the thread is narrower than the other lug 5.

It is further pointed out that lugs 4 are tapered in stepped manner towards the free end, the first taper being spaced from the bending edge of the stop springs, the second taper is located on the first bending edge of the offset and the third taper on the second bending edge of the offset.

This can more particularly be seen from Figure 3, which shows the stamped/bent part afterthe stamping process and before the bending process.

The invention is not restricted to the embodiment above-described and can be varied in various ways within the scope of the invention as defined in the appended claims.

Claims (15)

1. An oven luminaire comprising: an insulating base for carrying electric contacts and for receiving a lamp.

a socket secured to the base and for anchoring the luminaire to the oven wall, and a transparent cover detachably connected to the socket wherein: the socket is formed as an element stamped and bent from sheet metal which includes an annular collar from which depend angularly spaced lugs extending first downwardly towards the base and second are bent with end portions extending radially inwards, said end portions lying on a helix to enable a screwthreaded collarto be detachably screwed thereto.

2. An oven luminaire comprising a base made from insulating material for receiving electric contacts and a lamp, a socket made from metal for anchoring the luminaire in a wall recess of the oven or the like and a glass cover connectable to the socket, the socket being frontally provided with a collar and radially outwardly projecting fastening elements and is optionally connectable by means of cut sheet metal lugs to a socket base, the socket being internally provided with a screw-in thread for the end portion of the glass cover also provided with a screwthread, wherein the socket is constructed as a stamped/bent part with an annular, substantially flat collar which has first lugs (which are optionally cut and bent at least approximately at right angles from the ring plane) serving as fastening elements, the collar between said first lugs has further cut second lugs, which are bent at least approximately at right angles from the ring plane and whose ends are bent at least once more radially inwards and approximately at right angles, said bent ends having a level-differing spacing from the ring plane, and the ends are arranged on an imaginary helix whose pitch corresponds to the thread pitch of the glass cover and these ends thus form the screw-in thread.

3. An oven luminaire according to claim 2, wherein the first lugs are constructed as a stop spring and are cut freely towards the collar each at least approximately parallel to the edges of the particular first lug, and are bent radially outwards in approximately V-shaped manner.

4. An oven luminaire according to claims 2 or 3, wherein the base has a radially extending collar with axial engagement slots for the free ends of the first lugs, said ends passing through engagement slots and being bent to the rear of the collar.

5. An oven luminaire according to any one of the claims 2 to 4, wherein four first lugs are uniformly distributed around the circumference of collar and in each case two second lugs are formed between adjacent first lugs.

6. An oven luminaire according to any one ofthe claims 2 to 5, wherein the collar is curved in an approximately V-shaped manner.

7. An oven luminaire according to any one of the claims 2 to 6, wherein the first lugs are radially inwardly offset between the bending line of stop springs and the end portions are insertable in engagement slots.

8. An oven luminaire according to any one of the claims 2 to 7, wherein the end portions of the first lugs each have a projection in the vicinity of the walls of engagement slots.

9. An oven luminaire according to any one of the claims 2 to 8, wherein the collar of the base is recessed in a radially spring-back manner in the area between engagement slots.

10. An oven luminaire according to any one of the claims 2 to 9, wherein the collar has a further cut lug which is bent at right angles and whose free end is constructed as a plug.

11. An oven luminaire according to claim 10, wherein the said further cut lug constructed as the plug is arranged between two second lugs, whereof one forms the start of the thread.

12. An oven luminaire according to claim 11, wherein the two second lugs forming the start of the thread are narrower than the rest of the second lugs.

13. An oven luminaire according to any one of the claims 2 to 12, wherein the first lugs are tapered in stepwise manner towards their free ends, the first taper being spaced from the bending edge of stop springs, the second taper being located on the first bending edge of the offset and the third taper being located on the second bending edge of the offset.

14. An oven luminaire according to any one of the claims 2 to 13, wherein the base is formed of plastics material.

15. An oven luminaire substantially as hereinbefore described with reference to the accompanying drawings.