GB2227376A

GB2227376A - Removable electric lighting fitting

Info

Publication number: GB2227376A
Application number: GB8827319A
Authority: GB
Inventors: Raymond Wiltshire; Morris Kleiner; David Morgan; Colin Moore-Fay; Herbert Budwig; Stan Foster-Rooke; Philip Wright
Original assignee: HITECH LIGHTING PLC
Current assignee: HITECH LIGHTING PLC
Priority date: 1988-11-23
Filing date: 1988-11-23
Publication date: 1990-07-25
Also published as: GB8827319D0

Abstract

A downlighter light fitting comprises an outer part which normally remains in an installed position (e.g. in a ceiling) and an inner assembly or "shuttle" which is readily removable from, and replaceable in, said outer part. The "shuttle" comprises a lampholder retained by bent-over end portions of limbs (23) of springs of the outer part. Removal and replacement of the "shuttle" is effected by a minor upward movement which displaces the bent-over ends of the limbs (23) of the springs retaining recesses. As replacement is effected, said ends move into engagement with said recesses. The fitting allows a lamp replacement or a repair to be effected at a site remote from the point of use of the light fitting so that the hazard time inevitably spent on a ladder, chair or the like is at a minimum. <IMAGE>

Description

ELECTRIC LIGHTING This invention relates to electric lighting and particularly to so-called "downlighter" light fittings of the kind where a lamp is recessed behind a bezel, the latter being mounted substantially flush with the exposed surface of a ceiling or other surface.

Such downlighter fittings are well known and are very popular for business, industrial and domestic use.

They work effectively but, of course, replacement of the lamp bulbs is necessary at intervals which can be relatively frequent if a large number of such lamps is involved.

Generally speaking, in order to reach such a lamp and its mounting, it is necessary to pull the lamp and the mounting downwardly through the bezel whilst standing on a ladder, chair or the like and to change that lamp and/or perform a corrective operation on its mounting, still precariously mounted on the ladder, chair or the like which is sometimes behind an opaque door. The re-lamped and/or repaired mounting is restored to its operative position by pushing upwardly through the bezel.The dangers that are inherent in such an operation are too obvious to require stating in detail and it is a principal object of the present invention greatly to reduce these dangers by providing an assembly that can quickly and easily be removed from, and replaced in, its operative position so that the time spent on a ladder, chair or the like is as small as possible and any replacement or repair operation that is required can be carried out at leisure in a safe position and thus without significant danger.

According to the present invention, there is provided a downlighter light fitting comprising a mounting and an electric lamp operably connectable to that mounting, wherein said lamp and its mounting form parts of an assembly that are readily removable from, and replaceable in, the remainder of the fitting.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 is a side elevation of a complete downlighter light fitting in accordance with the invention, Figure 2 is a side elevation as seen in a horizontal direction that is perpendicular to the viewing direction of Figure 1, and Figure 3 is a side elevation as seen in the same direction as Figure 2 but showing an internal mounting of the assembly of Figure 2 that, in accordance with a principal feature of the invention, is removable from, and replaceable in, the remainder of the fitting.

Referring to the accompanying drawings, the downlighter light fitting that is illustrated therein has a circular bezel 1 that is intended to be disposed substantially flush to the lower surface of a ceiling or the like. The bezel 1 may be white, black, gold, chrome, graphite grey or may have any other desired colour or finish that may match, or contrast with, that of the ceiling itself. In addition, whilst it is convenient for the bezel 1 to be circular, it may be square or may have any other shape.

Two brass or other pins 2 project upwardly from a top plate 5 of a removable shuttle assembly of the fitting. These pins 2 are spaced apart and are substantially parallel to one another, each of them being seated in a corresponding ceramic or other insulating bush 4 and the lowermost end of each pin 2, beneath the corresponding bush 4, being connected to a bayonet or Edison Screw lamp holder 13 in a substantially conventional manner by corresponding flexible conductors 3 each of which is insulated except at its opposite ends.

The fitting comprises an outer part which will normally remain in its installed position in a ceiling or the like and this outer part exhibits a pair of phosphor bronze or other contact clips 6 each positioned to make a conductive connection to a corresponding one of the pins 2. Each contact clip 6 is connected by a conducting screw to a terminal post 7 which post, in turn, is connected to the base of a corresponding hexagonal brass bush 8. Each bush 8 is formed with a screw-threaded hole which receives a screw 9 to enable the bush 8 concerned to be reliably, and substantially permanently, connected to an electrical conductor which will supply the lamp that will be installed in the fitting.It can be seen in Figure 2 that an earthing screw 10, provided with appropriate washers, is secured to an upper horizontal plate of opposite downwardly extending portions 11 of the outer fixed part of the fitting.

The outer part of the fitting which is being described carries, on two horizontal tongues 14, a pair of coil springs 15 terminating in long substantially straight limbs 16. As can be seen in Figure 1, the limbs 16 at each side of the fitting are integrally interconnected by a horizontal portion 17. The opposite straight ends of the two springs 15 are entered into fixed anchorages 18. As previously mentioned, the outer part of the fitting which is being described normally remains in a fixed position in a ceiling or the like and horizontal portions 17 of the springs 15 are manually twisted upwardly, further to tighten the coils of these springs 15, by the person who initially installs the fitting.At least the horizontal portions 17 of the springs then firmly engage the ceiling in which the fitting is to be installed and/or other members so that the outer part of the fitting will not be removed downwardly when a lamp bulb change or other operation is necessary.

Substantially symmetrically identical retention springs 19 are arranged at opposite sides of the downwardly extending portion 11 of the outer fixed part of the fitting. Each retention spring 19 is formed from heat treated stainless steel spring wire and its upper end is bent through substantially 1800 around an anchorage 20 (Figure 2), a washer 21 being provided to ensure that the spring 19 does not become disengaged from the anchorage 20.The spring 19 has a short downwardly extending limb 22 and a much longer downwardly extending limb 23 the opposite ends of both of these limbs being bent over inwardly through substantially 900 with the upper bent over portion entered into a simple hole in the adjoining portion 11 whilst the lower bent over portion, at the lower end of the limb 23, is entered through a slot 24 in the same portion 11 where it normally contacts a lower recess 25 in a member 26 whose shape can best be seen in Figure 3 of the drawings.

A coiled compression spring 27 has its upper end anchored to the upper plate of the outer part of the fitting that will remain in place, said spring 27 extending downwardly to urge the top plate 5 of the removable inner portion or "shuttle" of the fitting in the same direction.

If a lamp in the holder 13 should fail, or if some component of the removable portion or shuttle of the fitting should break or cause trouble, an operator who has to reach the downlighter fitting to change the lamp and/or effect a repair merely stands on a ladder or chair and pushes, through a central circular hole of the bezel 1, the lamp and the internal portion or shuttle of the fitting upwardly. This initially further compresses the spring 27 and causes the pins 2 to move further into the clips 6. However, at the same time, the member 26 moves upwardly so that the lower recess 25 thereof moves out of engagement with the inwardly turned portion at the lower end of the limb 23 of the spring 19.The spring 19 is arranged so that the portion in question tends to be disposed centrally of the slot 24 and the result is that the inwardly projecting portion at the lower end of the limb 23 of the spring 19 moves to the right as seen in Figure 2 after which, as soon as the operator no longer pushes the inner part of the fitting upwardly, the spring 27 will push that inner part downwardly and out of the central hole in the bezel 1, this movement being ended merely by pulling downwardly so that the pins 2 leave the clips 6 and the spring 27 no longer engages the top plate 5. The two springs 19 at opposite sides of the fitting, which no longer retain the removable inner portion or shuttle thereof, engage the members 26 by their lower inwardly directed ends which move upwardly along the righthand sides of the two members 26 as the portion shown in Figure 3 is removed.Upon reinsertion of that portion after the lamp has been replaced or a repair has been effected on a bench or table at a safe position remote from the installation site, the inwardly bent lower ends of the springs 19 move downwardly along the lefthand sides of the members 26 as seen in Figure 3 as installation proceeds until they snap past the projections immediately to the left of the recesses 25. If the upward installation pressure is then discontinued, the inner portion or "shuttle" of the fitting will remain reliably retained in its operative position with the lower inwardly bent over ends of the retention springs 19 in the corresponding recesses 25 and with the spring 27 compressed to some extent to prevent any vibration or the like.

It will be appreciated that a downlighter light fitting in accordance with the invention enables an operator to remove, and subsequently replace, the inner mounting or "shuttle" of the fitting from the relatively fixed outer part thereof so that the lamp of the fitting can be replaced or any repair that may be required can be undertaken either or both at a site remote from the position of use itself so that the time taken on a ladder, chair or the like is an absolute minimum.

Although a light fitting in accordance with the invention will normally operate lamps that require "mains" electricity, it will immediately be apparent that this is by no means essential and that, for a number of purposes, lamps which operate at a relatively low voltage could equally well be installed in each of the holders 13.

Claims

CLAIMS:

1. A downlighter light fitting comprising a mounting and an electric lamp operably connectable to that mounting, wherein said lamp and its mounting form parts of an assembly that are readily removable from, and replaceable in, the remainder of the fitting.

2. A fitting according to claim 1, wherein, when said assembly is retained in its operative position in the remainder of the fitting, that operative position involves the compression of spring means.

3. A fitting according to claim 1 or claim 2, wherein said assembly comprises shaped members exhibiting recesses, the recesses in these shaped members being arranged to cooperate, in the retained or operative position of the assembly, with portions of retention springs.

4. A fitting according to claim 3, wherein, in the released or inoperative position of said assembly, said portions of the retention springs are disengaged from said recesses and are slidable along curved edges of the members which exhibit said recesses.

5. A fitting according to any preceding claim, wherein the fitting exhibits an earthing connection.

6. A fitting according to any preceding claim, wherein the fitting exhibits means by which said remainder thereof will tend positively to be retained in its operative position upon the removal of said assembly therefrom.

7. A fitting according to any preceding claim, wherein said fitting includes a bezel that is intended to be disposed substantially flush to the lower surface of a ceiling or the like.

8. A downlighter light fitting substantially as hereinbefore described with reference to the accompanying drawings.

8. A fitting according to any preceding claim, wherein said assembly comprises a bayonet-type lamp holder.

9. A downlighter light fitting substantially as hereinbefore described with reference to the accompanying drawings.

Amendments to the claims have been filed as follows

1. A downlighter light fitting comprising a mounting and an electric lamp operably connectable to that mounting, wherein said lamp and its mounting form parts of an assembly that are readily removable from, and replaceable in, the remainder of the fitting, said assembly comprising shaped members exhibiting recesses, the recesses in these shaped members being arranged to co-operate, in the retained or operative position of the assembly, with portions of retention springs, and wherein, in the released or inoperative position of said assembly, said portions of the retention springs are disengaged from said recesses and are slidable along edges of the members which exhibit said recesses.

2. A fitting according to claim 1, wherein said edges of the members which exhibit said recesses are curved edges.

3. A fitting according to claim 1 or 2, wherein, when said assembly is retained in its operative position in the remainder of the fitting, that operative position involves the compression of spring means.

4. A fitting according to any preceding claim, wherein the fitting exhibits an earthing connection.

5. A fitting according to any preceding claim, wherein the fitting exhibits means by which said remainder thereof will tend positively to be retained in its operative position upon the removal of said assembly therefrom.

6. A fitting according to any preceding claim, wherein said fitting includes a bezel that is intended to be disposed substantially flush to the lower surface of a ceiling or the like.

7. A fitting according to any preceding claim, wherein said assembly comprises a bayonet type lamp holder.