GB2149228A - An electric light source socket - Google Patents

Abstract

A socket for an electric lighting set comprises an outer housing 1 containing an inner device 2 and formed with a radially inward flange 13. A bulb can be inserted into the housing 1 and held in the device 2 between terminal plates mounted in slots 3 and 4. The device 2 is formed with a head 10 which engages behind the flange 13 to retain the device 2 in the housing 1, a taper on the head allowing the head to be pushed past the flange. <IMAGE>

Description

SPECIFICATION An electric light source socket According to the present invention, there is provided a socket for an electric light source, comprising a tubular outer housing for receiving at one end said light source and at the other end electrical supply conductors, and an inner device in said housing serving to mount electrical terminal members connected to said conductors for supply of electric current to said light source, said inner device being formed with a projection engaging behind a shoulder of said housing to restrain said device against movement relative to said housing in the direction from said other end to said one end.

In order that the invention may be clearly understood and readily carried into effect, reference will now be made, by way of example, to the accompanying drawing, in which Figure 1 shows a vertical axial sectional view through a socket for an electric lamp bulb, and Figure 2 shows a plan view of an inner device of said socket.

Referring to the drawings, the socket is one of a number of identical sockets of a Christmas electric lighting set and comprises a tubular, outer housing 1, and an inner device 2 in the housing 1. The housing 1 is for most of its length internally of a circular cylindrical form extending from its upper extremity. However, its lower end is formed with an annular, radially inward flange 1 3. The housing 1 has been moulded in one piece from electrically insulating, resilient plastics. The device 2 has also been moulded in one piece from electrically insulating, resilient plastics, and is formed with two pairs of vertical slots 3 and 4, each pair of which receives a vertical electrical terminal plate (not shown) for contacting the respective terminals of the bulb itself (not shown).The bulb is inserted into the upper end of the housing 1 and held in the device 2 between the terminal plates mounted in the slots 3 and 4. Electrical leads (not shown) extend from the respective lower ends of the terminal plates down respective vertical slots 5 in the device 2, through respective right-angles around a horizontal annular slot 6 in the device 2, up respective vertical slots 7 in the device 2, over a central core 8 of the device 2, down the respective other slots 7 and respective extensions 9 thereof, to the lower ends of the housing 1 3 and the device 2, and thence towards a mains supply. Thus, each lead is effectively looped over the central core 8.At its lower end, the device 2 is formed with a head 10 which thus provides a projection which engages behind the flange 3 to restrain the device 2 against upward movement relative to the housing 1.

The head 10 is interrupted by the continuations 9. Generally speaking, the device 2 is a close fit in the housing 1 and thus is restrained by the flange 1 3 also from moving downwards relative to the housing 1. The head 10 is of a generally frusto-conical form, with its smaller diameter smaller than the internal diameter of the flange 13, but with its larger diameter larger than the internal diameter of the flange 1 3 but less than the internal diameter of the remainder of the housing 1. The frusto-conical surface of the head 10 converges downwardly, whereby pressing of the head 10 downwards past the flange 1 3 during assembly of the socket is facilitated.

The provision of the head 10 has the advantage of restraining the device 2 from being pulled upwards out of the housing 1, with consequential dangerous exposure of the terminal plates, for example by someone simply wishing to remove the bulb from the socket and replace it by another bulb.

1. A socket for an electric light source, comprising a tubular outer housing for receiving at one end said light source and at the other end electrical supply conductors, and an inner device in said housing serving to mount electrical terminal members connected to said conductors for supply of electric current to said light source, said inner device being formed with a projection engaging behind a shoulder of said housing to restrain said device against movement relative to said housing in the direction from said other end to said one end.

2. A socket as claimed in claim 1, wherein said shoulder constitutes part of an internal protrusion of said housing.

3. A socket as claimed in claim 2, wherein the outline of said projection transverse to said housing decreases in size progressing in the direction from said one end towards said other end, so that a lateral surface of said projection converges progressing in the latter direction, the arrangement being such that, during insertion of said device into said housing in the latter direction, said lateral surface encounters said protrusion and can be resiliently urged past said protrusion until said projection engages behind said shoulder.

4. A socket as claimed in claim 3, wherein said lateral surface is of a substantially frustoconical form and said protrusion is of a substantially circular form.

5. A socket as claimed in claim 2, 3, or 4, wherein said protrusion is in the form of a flange at said other end.

6. A socket as claimed in any one of claims 2 to 5, wherein, with said projection behind said shoulder, said protrusion limits further movement of said device relative to said housing in the direction from said one

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

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION An electric light source socket According to the present invention, there is provided a socket for an electric light source, comprising a tubular outer housing for receiving at one end said light source and at the other end electrical supply conductors, and an inner device in said housing serving to mount electrical terminal members connected to said conductors for supply of electric current to said light source, said inner device being formed with a projection engaging behind a shoulder of said housing to restrain said device against movement relative to said housing in the direction from said other end to said one end. In order that the invention may be clearly understood and readily carried into effect, reference will now be made, by way of example, to the accompanying drawing, in which Figure 1 shows a vertical axial sectional view through a socket for an electric lamp bulb, and Figure 2 shows a plan view of an inner device of said socket. Referring to the drawings, the socket is one of a number of identical sockets of a Christmas electric lighting set and comprises a tubular, outer housing 1, and an inner device 2 in the housing 1. The housing 1 is for most of its length internally of a circular cylindrical form extending from its upper extremity. However, its lower end is formed with an annular, radially inward flange 1 3. The housing 1 has been moulded in one piece from electrically insulating, resilient plastics. The device 2 has also been moulded in one piece from electrically insulating, resilient plastics, and is formed with two pairs of vertical slots 3 and 4, each pair of which receives a vertical electrical terminal plate (not shown) for contacting the respective terminals of the bulb itself (not shown).The bulb is inserted into the upper end of the housing 1 and held in the device 2 between the terminal plates mounted in the slots 3 and 4. Electrical leads (not shown) extend from the respective lower ends of the terminal plates down respective vertical slots 5 in the device 2, through respective right-angles around a horizontal annular slot 6 in the device 2, up respective vertical slots 7 in the device 2, over a central core 8 of the device 2, down the respective other slots 7 and respective extensions 9 thereof, to the lower ends of the housing 1 3 and the device 2, and thence towards a mains supply. Thus, each lead is effectively looped over the central core 8.At its lower end, the device 2 is formed with a head 10 which thus provides a projection which engages behind the flange 3 to restrain the device 2 against upward movement relative to the housing 1. The head 10 is interrupted by the continuations 9. Generally speaking, the device 2 is a close fit in the housing 1 and thus is restrained by the flange 1 3 also from moving downwards relative to the housing 1. The head 10 is of a generally frusto-conical form, with its smaller diameter smaller than the internal diameter of the flange 13, but with its larger diameter larger than the internal diameter of the flange 1 3 but less than the internal diameter of the remainder of the housing 1. The frusto-conical surface of the head 10 converges downwardly, whereby pressing of the head 10 downwards past the flange 1 3 during assembly of the socket is facilitated. The provision of the head 10 has the advantage of restraining the device 2 from being pulled upwards out of the housing 1, with consequential dangerous exposure of the terminal plates, for example by someone simply wishing to remove the bulb from the socket and replace it by another bulb. CLAIMS

1. A socket for an electric light source, comprising a tubular outer housing for receiving at one end said light source and at the other end electrical supply conductors, and an inner device in said housing serving to mount electrical terminal members connected to said conductors for supply of electric current to said light source, said inner device being formed with a projection engaging behind a shoulder of said housing to restrain said device against movement relative to said housing in the direction from said other end to said one end.

2. A socket as claimed in claim 1, wherein said shoulder constitutes part of an internal protrusion of said housing.

3. A socket as claimed in claim 2, wherein the outline of said projection transverse to said housing decreases in size progressing in the direction from said one end towards said other end, so that a lateral surface of said projection converges progressing in the latter direction, the arrangement being such that, during insertion of said device into said housing in the latter direction, said lateral surface encounters said protrusion and can be resiliently urged past said protrusion until said projection engages behind said shoulder.

4. A socket as claimed in claim 3, wherein said lateral surface is of a substantially frustoconical form and said protrusion is of a substantially circular form.

5. A socket as claimed in claim 2, 3, or 4, wherein said protrusion is in the form of a flange at said other end.

6. A socket as claimed in any one of claims 2 to 5, wherein, with said projection behind said shoulder, said protrusion limits further movement of said device relative to said housing in the direction from said one end to said other end.

7. A socket as claimed in any preceding claim, and constituting one of a plurality of identical sockets of an electric lighting set.

8. A socket, substantially as hereinbefore described with reference to the accompanying drawings.