GB2236219A - Trailing multi-socket outlet - Google Patents

Abstract

A trailing multi-socket outlet comprises a housing, six identical substantially straight metal strips (64, 66, 68) disposed longitudinally in the housing, two of the strips being arranged for coupling to the phase pin of a plug, two to the neutral pin, and two to the ground plug, the strips also defining contact indentations (62) arranged for friction fit with the pins of a plug. The axis of each socket outlet is rotated by an angle alpha to an axis perpendicular to that of the housing. Contact indentations (62) may be suitable for round-pin plugs (figs 4a, 4b not shown). <IMAGE>

Description

SOCKET STRIP The present invention relates to electric socket strips Electric socket strips are known in the art. Such strips are designed to permit the simultaneous utilization of a plurality of plugs in a single outlet socket. Such strips are generally limited to use of plugs having a rear cable outlet, those having a side cable outlet (right-angle plug) being too bulky to fit adjacent one another.

Furthermore, conventional socket strips generally comprise a great number of internal parts. Each like pole (phase, neutral, and ground) must be connected together to the appropriate electric wire, and each pole requires a contact coupling it to the connecting wire. Generally, the pole interconnections comprise individual wires coupled to the contact, as by screws, and the contact is generally a small piece of metal retained in place, as by screws, within the socket strip housing.

There is known a socket strip manufactured by MK Electric Ltd., London, England, shown in Fig. 1, wherein each pole interconnection comprises a single strip of metal bent to shape to fit within the housing. While this is an improvement over individual connecting wires, three differently shaped strips are required, and the contacts are still individual pieces of metal.

It is an aim of the present invention to provide a socket strip which is simple, requires a minimum of parts, is inexpensive to manufacture and can be used with plugs having either side or rear cable outlets.

There is thus provided in accordance with the present invention a socket strip including a housing, six identical substantially straight metal strips disposed longitudinally in the housing, two of the strips being arranged for coupling to the phase pin of a plug, two to the neutral pin, and two to the ground pin of a plug, the strips also defining contact indentations arranged for friction fit with the pins of a plug.

According to a preferred embodiment, the housing includes plastic or other insulating material disposed between the strips connecting the electrical poles.

According to a further aspect of the present invention there is provided -a multi-socket strip including a plastic moulded box including two mating parts, a top cover part defining a plurality of sockets, each plug receivina location defining three apertures adacted te receive a complementary pin of a plug, and a bottom part having a plurality of pin supports moulded in plastic in register with the apertures in the top cover part; and three pairs of identical, essentially straight metal strips disposed in the bottom part, each pair defining at integrally formed contact at one socket pin position of each socket and arranged to be coupled to the appropriate pole of the entering electrical power supply source According to a preferred embodiment, each of the sockets is rotated such that the socket axis defines an angle between 150 and 300, most preferably 78026', with an axis perpendicular to the strips.

Embodiments of the invention are described, by way of example only, with reference to the accompanying drawings in which: Figs la and ib are plan views of the respective top and bottom parts of a socket strip according to the prior art; Figs. 2a and 2b are plan views of the respective top and bottom parts of a socket strip constructed and operative in accordance with one embodiment of the s invention; Figs. 3a and 3b are plan views of the respective top and bottom parts of a socket strip constructed and operative in accordance with an alternate embodiment of the present invention; and Figs. 4a and 4b are plan views of the respective top and bottom parts of a socket strip constructed and operative in accordance with another embodiment of the present invention.

With reference t6 Figs. la and Ib, there are shown respective top and bottom parts of a socket strip according to the prior art. The socket strip comprises a plastic housing including a top cover 10 and a bottom part 12. Cover 10 defines a plurality of pin receiving apertures 14 and 16. It will be appreciated that the socket strip is particularly adapted to the type of plug utilized in Great Britain. In this plug, the phase and neutral pins are identical and aligned with one another, while the ground pin is larger and disposed perpendicular thereto. Accordingly, apertures 14 for the phase and neutral pins are disposed parallel to the longitudinal axis of the housing while apertures 16 for the ground are disposed perpendicular thereto.

As can be seen in Fig, ib, each of the three types of pins is connected to one another by a differently shaped brass strip 18, 20, 22. The brass strips are coupled to the wires leading to the electric supply. In addition, a plurality of metallic contacts 24 are provided, one associated with each of the pins of each plug. Thus, this socket, while simpler than conventional wired sockets, requires a large number of parts, a variety of moulds for the connecting strips, and a great deal of labour on assembly.

The present invention relates to simplified socket strips for use with either side cord or rear cord electric plugs. According to the present invention, the socket strip comprises a molded plastic housing which includes guide and insulation means for a plurality of essentially straight strips which act as the wiring between the pins of the plugs and as the contacts with each pin.

According to a preferred embodiment of the invention. there are provided six strips, esch pair of strips being coupled to one of phase, neutral or ground.

Most preferably, all six strips are identical.

Alternatively, four strips may be identical with the other pair identical to one another. The sockets in the strip may be arranged in an array, each perpendicular to the longitudinal axis of the housing, as known, or at an angle thereto, in order to facilitate placement of the substantially linear strips.

Referring now to Figs. 2a and 2b, there is shown in plan view the respective top and bottom parts of socket strip constructed and operative in accordance with one embodiment of the present invention. The socket strip comprises a plastic housing including a removable top portion 30 and a bottom portion 32. Top portion 30 defines a number of sockets including a plurality of pin receiving apertures 34, 36 as known.

The housing preferably comprises a plastic box made of an engineering plastic with high resistance to heat and fire, such as "Noryl", manufactured by General Electric Plastic Co., U.S.A., Nylon 6/6, ABS, or the like. The socket strip may comprise any desired number of sockets, preferably between three and eight sockets, and most preferably four or six sockets.

As seen .in Fig. 2b, bottom portion 32 includes three pairs of metal strips 40, 42, 44 each arranged for coupling to an outside source of electricity as at connection points 38. Metal strips 40, 42 and 44 are substantially straight strips of brass, copper or any other metal which ensures electrical contact (i.e., low resistance) defining contact indentations 46 periodically spaced therealong.

According to the most preferred embodiment, illustrated in Fig. 3, all six strips are identical.

According to an alternate embodiment, illustrated in Figs. 2a and 2b, the four strips 40, 42 are identical while the pair of strips 44 to ground are different therefrom. It will be appreciated that the strips are arranged in the housing bottom 32 so that contact indentations 46 are in registration with apertures 34, 36 in the assembled socket Housing bottom 32 is preferably moulded to define guide means 48 for supporting the strips. Guide means 48 also serve as spacer elements to prevent inadvertent contact between the various electrical poles.

Alternately, guide means 48 may define plastic sleeves arranged to surround and support the contact indentations 46.

According to the illustrated embodiment, a seat 50 is provided in the housing for a cable 52 which is coupled to the electric power supply. According to one embodiment, a two-pole switch (not shown) is coupled between cable 52 and the metal strips, as known. The two-pole switch preferably has an associated small electric LED which turns on when current is passing through the strip. The socket strip may be mounted on a wall, a work table or any other fixture, and when the plugs are plugged in, the power is turned on by means of the switch.

Referring now to Figs. 3a and 3b, there are shown respective top and bottom portions of a socket strip constructed and operative in accordance with an alternate embodiment of the invention. Like elements in Figs. 2a and 2b have like reference numerals. According to this embodiment, each of the sockets is rotated such that the socket axis defines an angle alpha of between 15 and 300, most preferably 18026', with an axis perpendicular to the strips. Accordingly, the pin receiving apertures 34, 36 in top portion 60 are disposed at this angle as are the contact indentations 62 which are in registration with the apertures.

It will be appreciated that, due to the rotation of the sockets, strips 64, 66 and 68 are differently shaped from those of Fig. 2b. This angle permits the usage of strips which are all identical to one another.

In Figs. 4a and 4b there is shown another alternate embodiment of the invention, similar to that of Figs 3a and 3b. In this embodiment, provision is made for circular pins or for plugs having pins of slightly different size or shape than those of the previous embodiments. Accordingly, apertures 72 and 74 in top portion 70 are circular in shape, while contact indentations 78 in strips 76 are hemispherical.

It is a particular6 feature of a preferred embodiment of the present invention that six identical brass strips are utilized. Since at least four of the strips are identical, the required number of moulds and the necessary stock are greatly reduced. This will substantially reduce the cost of production of a multi socket strip by reducing the raw material costs and the labour costs for assembly. By using these strips, socket production can be industrialized, with machines placing the metal strips and connecting them to the appropriate poles.

It will be appreciated by those skilled in the art that the invention is not limited to what has been shown and described hereinabove by way of example.

Rather, the scope of the invention is limited solely by the claims which follow.

Claims (1)

1. CLAIMS:

   7. A socket strip comprising: a housing defining at least three sockets; and six substantially straight metal strips disposed longitudinally in the housing, two of the strips being arranged for coupling to the phase pins of at least three plugs, two to the neutral pins thereof, and two to the ground pins thereof; said strips also defining contact indentations arranged for friction fit with the pins of said at least three plugs.

   2. A socket strip according to claim 1 and wherein said six strips are identical to one another.

   3. A socket strip according to claim 1 and wherein four of said strips are identical to one another, and two of said strips are identical to each other but different from said four strips.

   4. A socket strip according to any of the preceding claims and further comprising spacer elements disposed between the pairs of strips.

   5. A socket strip according to claim 4 and wherein said spacer elements are integrally moulded with the housing.

   6. A multi-socket strip comprising: a plastic moulded box comprising two mating parts, a top cover part defining a plurality of sockets, each socket defining three apertures adapted to receive a complementary pin of a plug, and a bottpm part; and three pairs of essentially straight metal strips disposed in the bottom part, each par defining an integrally formed contact means at one pin receiving position of each socket and arranged to be coupled to the appropriate pole of the entering electrical power supply source.

   7. A multi-socket strip according to claim 6 and wherein said bottom part defines a plurality of strip guide means integrally formed therewith.

   9. A multi-socket strip according to either of claims 5 and 6 and wherein said six strips are identical to one another.

   10. A multi-socket strip according to either of claims 5 and 6 and wherein four of said strips are identical to one another, and two of said strips are identical to each other but different from said four strips.

   11. A multi-socket strip according to any of the preceding claims and wherein each of the sockets is rotated such that the socket axis defines an angle of between 15 and 300 with an axis perpendicular to the strips.

   12. A multi-socket strip according to claim 11 and wherein said angle is 180261.

   13. A socket strip substantially as hereinbefore described with reference to any of Figures 2 to 4 of the accompanying drawings.

   14. A multi-socket strip substantially as hereinbefore described with reference to any of Figures 2 to 4 of the accompanying drawings.