GB2105531A

GB2105531A - Improvements relating to fittings for light bulbs

Info

Publication number: GB2105531A
Application number: GB08127448A
Authority: GB
Inventors: Brian Henry Croker
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-09-10
Filing date: 1981-09-10
Publication date: 1983-03-23

Abstract

A socket for the receipt of a light bulb or some other plug-in electrical fitting has a collar 12 which will receive the base portion of the fitting so that the fitting will make contact with pins 14 and 15 connected to the electrical supply. Levers 16 are biased by a spring 24 into contact with the outside of the collar 12 to cause shaped portions 18 to project through slots in the collar for location in a groove formed around the circumference of the base of the fitting to hold the fitting securely in place. This arrangement provides for rapid insertion and release of the fitting within the socket. As an alternative the base of the fitting could have projecting pins 27 received in vertical slots in the collar 12 and held in place by releasable arms 30 which are biased downwardly into contact with the projecting pins. <IMAGE>

Description

SPECIFICATION Improvements relating to fittings for light bulbs This invention is concerned with fittings for receiving light bulbs. The conventional form of fitting comprises a bayonet pin on the bulb received in basically L-shaped slots, requiring the bulb to be pushed in and twisted for complete insertion. This can prove difficult to operate by persons, for example having arthritic fingers and there is the general problem met when trying to remove a hot bulb from the fitting. In any case, continual twisting of the lamp tends to displace the glass globe from the metal cap into which it is received.

According to the present invention there is provided a light bulb fitting comprising a collar for receipt of the base of the light bulb, a gripping device for locating on or in pins or grooves formed on the light bulb base, and biassed in a location holding position, and a lever device on the exterior of the collar for moving the gripping device against the bias to enable the light bulb to be removed from the collar.

With such an arrangement it is possible to provide that the bulb is merely pushed into place and is then automatically held by the gripping device but can of course be released by operating the external lever device.

In the preferred arrangement the gripping device comprises a pair of arms biassed inwardly through slots in the sides of the collars. These arms could locate over pins formed on the light bulb but preferably will be received in slots formed in the light bulb base. If the arm portions projecting inwardly through the slots have rounded surfaces on their inner edges then it may well be possible to push the base of the light bulb past the arm portions until they clip onto the location parts on the light bulb base. In another construction the arm portions which project inwardly through the slots provide straight edges on their inner surfaces. These straight edges will lie in slots of complementary straight shape in the light bulb base.

The biassing means may comprise an arrangement wherein the ends of the arms remote from the lever device are linked by a section of spring metal acting as the biassing means. In a preferred alternative, however, the two lever arms may be biassed apart where they project outside the collar by a spring clip.

In an alternative form of light bulb fitting which is particularly designed to receive light bulbs of a conventional form having extending bayonet pins, the collar may be provided with substantially vertical slots from the top edge for receipt of pins on the light bulb and the gripping device comprises pivoted arms biassed down towards the bases of the two slots to hold the pins on the light bulb. The pivoted arms may be linked to a common operating lever and can be biassed by means of compression springs connected between one of those arms and a fixed portion of the light bulb fitting.

The invention also extends to a combination of a light bulb fitting as hereinbefore defined in accordance with the invention and a light bulb designed to be held by the gripping means. If the bulb is of the type provided with grooves in the base thereof a single groove could be formed all around the base of the bulb. In this instance it is preferred that the electrical contacts for the bulb should be provided by a central stud and a separate surrounding ring of conductive material on the bottom surface of the base of the bulb.

The invention may be performed in various ways and preferred embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 illustrates a part of a light bulb fitting of this invention and a light bulb to be received therein, Figure 2 is a plan view of an alternative light bulb fitting of this invention, Figures 3 and 4 are side and underneath plan views respectively of a modified form of light bulb for use with the fitting as shown in Figure 2, and Figure 5 is a side view of a third form of light bulb fitting of this invention.

The fitting shown in Figure 1 comprises a collar portion 1 within which will be housed the normal contact pins. A piece of springy wire is welded at its centre part 2 to the collar 1 and forms two arms 3 which pass through slots 4 formed in the side walls of the collar 1. These arms then terminate in operating portions 5 which cross over one another and are provided with finger grip parts 6. The bulb for use with this fitting is also shown in Figure 1 and comprises a bulb portion 7 and a base 8 provided with contact studs 9. A slot 10 is formed in two opposite sides of the base 8.

When the light bulb is inserted into the collar 1 it will tend to push apart the arms 3 until they snap back into place in the grooves 10, thus holding the light bulb securely in the collar 1. The bulb can be released by pressing the portions 6 towards one another.

The light bulb fitting shown in Figure 2 has a base member 11 from which projects upwardly an inner collar 12 and an outer collar 13. Within the inner collar 1 2 are three contact pins of which pins 14 are for connection to one pole of a power supply and the central pin 1 5 is for connection to the other pole of a power supply. A bulb gripping device is formed by two levers 16 having operating parts 1 7. The other ends curve around the inner collar 12 and have shaped extensions 1 8 which pass through slots in the side walls of the collar 1 2 towards the interior of the fitting.

The extreme tips 1 9 of the arms 1 6 are received in slots formed in the outer collar 13 and help to make the unit more robust. The base portion of a light bulb to be received in the fitting shown in Figure 2 is illustrated in Figures 3 and 4. This base portion 20 is provided with a groove 21 towards its lower end which will receive the shaped portions 1 8 on the arms 1 6. The underneath surface of the base portion 20 is provided with two contact members joined to respective ends of the filament of the lamp. An outer ring-like contact member 22 will make contact with one or both of the pins 14 in the light bulb fitting of Figure 2 whilst the central contact piece 23 will contact the central pin 1 5 of the light bulb fitting.

The pins 14 and 1 5 will be spring-loaded to ensure firm contact and also to help the light bulb to be ejected when it has to be removed.

A light bulb of the form illustrated in Figures 3 and 4 is inserted into the fitting of Figure 2 by pressing the parts 1 7 of the arm 1 6 towards one another against the bias of a spring 24 so that the shaped portions 18 are retracted, enabling the light bulb to be pressed fully home. Alternatively, with suitable shaping of the parts the mere insertion of the light bulb will force the arms 1 6 outwardly until the shaped portions 18 snap into place in the annular recess 21 in the base of the light bulb.

In the embodiment shown in Figure 5 a standard light bulb is illustrated having a globe portion 25 and a base portion 26 provided with a pair of bayonet pins 27. These pins 27 slide down slots 28 formed on opposite sides of a collar 29 of the light bulb fitting. A pair of lever arms 30 biassed by spring 31 engage pins 27 to hold the light bulb in place but the bulb can be released by pressing a portion 32 of the lever 30 so that the pins 27 are free to slide out through the slots 28.

The lever 30 is pivotally mounted on a screwthreaded ring 33 received on a mounting portion 34 of the light bulb fitting. A spacer ring 35 is provided which will be removed to provide a suitable gap for receipt of the collar of the support of a lamp shade.

Although reference has been made solely to light bulbs, it should be understood that the invention also extend to any other plug-in electrical fittings, in particular the plugs for light extension leads which fit lamp sockets.

Claims (Filed on 10 Sept 1982) 1. A socket for receipt of a light bulb or other plug-in electrical fitting comprising a collar for receipt of the base of the fitting, a gripping device for locating on or in pins or grooves formed on the base of the fitting, and biased in a location holding position, and a lever device on the exterior of the collar for moving the gripping device against the bias to enable the fitting to be withdrawn from the collar.

2. A socket according to claim 1, wherein the gripping device comprises a pair of arms biased inwardly through slots in the sides of the collar.

3. A socket according to claim 2, wherein the arm portions projecting inwardly through the slots have rounded surfaces on their inner edges.

4. A socket according to claim 2, wherein the arm portions projecting inwardly through the slots provide straight edges on their inner surfaces.

5. A socket according to any one of claims 1 to 4, wherein the ends of the arms remote from the lever device are linked by a section of spring metal acting as the biasing means.

6. A socket according to claim 1, wherein the collar is provided with substantially vertical slots from the top edge for receipt of pins on the fitting and the gripping device comprises pivoted arms biased down towards the bases of the slots to hold the pins on the fitting.

7. A socket according to claim 1 and substantially as herein described with reference to the accompanying drawings.

8. The comoination of the socket according to any one of claims 1 to 7 and a light bulb or other plug-in electrical fitting designed to be held by the gripping means.

9. The combination according to claim 8, wherein the fitting is of a type provided with a single groove formed all round the base of the fitting.

10. The combination according to claim 9, wherein electrical contacts for the fitting are provided by a central stud and a separate surrounding ring of conductive material on the bottom surface of the base of the fitting.

11. A combination according to claim 8 and substantially as herein described with reference to the accompanying drawings.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. portions 1 8 on the arms 1 6. The underneath surface of the base portion 20 is provided with two contact members joined to respective ends of the filament of the lamp. An outer ring-like contact member 22 will make contact with one or both of the pins 14 in the light bulb fitting of Figure 2 whilst the central contact piece 23 will contact the central pin 1 5 of the light bulb fitting. The pins 14 and 1 5 will be spring-loaded to ensure firm contact and also to help the light bulb to be ejected when it has to be removed. A light bulb of the form illustrated in Figures 3 and 4 is inserted into the fitting of Figure 2 by pressing the parts 1 7 of the arm 1 6 towards one another against the bias of a spring 24 so that the shaped portions 18 are retracted, enabling the light bulb to be pressed fully home. Alternatively, with suitable shaping of the parts the mere insertion of the light bulb will force the arms 1 6 outwardly until the shaped portions 18 snap into place in the annular recess 21 in the base of the light bulb. In the embodiment shown in Figure 5 a standard light bulb is illustrated having a globe portion 25 and a base portion 26 provided with a pair of bayonet pins 27. These pins 27 slide down slots 28 formed on opposite sides of a collar 29 of the light bulb fitting. A pair of lever arms 30 biassed by spring 31 engage pins 27 to hold the light bulb in place but the bulb can be released by pressing a portion 32 of the lever 30 so that the pins 27 are free to slide out through the slots 28. The lever 30 is pivotally mounted on a screwthreaded ring 33 received on a mounting portion 34 of the light bulb fitting. A spacer ring 35 is provided which will be removed to provide a suitable gap for receipt of the collar of the support of a lamp shade. Although reference has been made solely to light bulbs, it should be understood that the invention also extend to any other plug-in electrical fittings, in particular the plugs for light extension leads which fit lamp sockets. Claims (Filed on 10 Sept 1982)

1. A socket for receipt of a light bulb or other plug-in electrical fitting comprising a collar for receipt of the base of the fitting, a gripping device for locating on or in pins or grooves formed on the base of the fitting, and biased in a location holding position, and a lever device on the exterior of the collar for moving the gripping device against the bias to enable the fitting to be withdrawn from the collar.