GB2381962A

GB2381962A - Modular power outlet

Info

Publication number: GB2381962A
Application number: GB0225178A
Authority: GB
Inventors: Clive Grenville Merrell
Original assignee: BRENCHAM
Current assignee: BRENCHAM
Priority date: 2001-11-07
Filing date: 2002-10-30
Publication date: 2003-05-14
Also published as: GB0225178D0; GB0126828D0

Abstract

A modular power outlet 10 having holes 13,14,15 for receiving a plug and electrical contacts within the holes to connect the plug pins to separate busbars 16,17,18. The busbars form male connectors 26 and female connectors 24 located at opposite ends of the housing. The structure allows individual modules to be interconnected.

Description

ELECTRICAL SOCKET This invention relates to an electrical socket of the general type incorporated into a power distribution unit (PDU) which provides a row of electrically interconnected sockets, each being adapted to have typically a two or three pin electrical plug engaged therewith.

Generally adjacent sockets of such a PDU are electrically connected by hard wiring, i. e. by means of electrical wiring utilising conventional screw terminals. This renders it difficult to reduce the depth of the housing forming the body of the PDU, something which is desirable when the PDU is to be used in a confined space, such as at the rear of a computer cabinet.

Moreover bad connections are possible with such hard wiring when using screw terminals. It is also desirable to reduce manufacturing labour costs for such PDUs.

An object of the invention is to provide an improved electrical socket of this type.

According to one aspect of the invention an electrical socket comprises a casing defining an inlet for reception of at least two pins of an electrical plug engageable with the socket, electrically conductive means within the casing, the pins of said plug being in electrical contact with the electrically conductive means when said plug is in engagement with the socket, in use, and said electrically conductive means defining one of a male connector and a female connector, such that said socket can be electrically interconnected, in use, by engagement of said one of said male and female connectors with the

other of said male and female connectors provided by a further electrical socket.

According to another aspect of the invention an electrical socket comprises a casing defining an inlet for reception of at least two pins of an electrical plug engageable with the socket, electrically conductive means within the casing extending from a first opening at one exterior part of the casing to a second opening at another exterior part of the casing, the pins of said plug being in electrical contact with the electrically conductive means when said plug is in engagement with the socket, in use, and said electrically conductive means defining a male connector at said first opening and a female connector at said second opening, such that two such electrical sockets can be electrically interconnected by the engagement of said male connector of one electrical socket with said female connector of the other electrical socket or vice versa.

Preferably the electrically conductive means are a number of busbars corresponding to the numbers of pins of said electrical plug.

According to a second aspect of the invention a power distribution unit comprises a plurality of said electrical sockets, according to said first aspect, electrically interconnected.

Preferably each of said electrical socket is fitted in a body of the power distribution unit by sliding, clipping or as a snap-fit. Desirably the body is of aluminium and conveniently the inlet of each electrical socket is at 45 to the length of the body.

The invention will now be described, by way of example, with reference to the accompany drawings, in which: Figure 1 is an exploded view of two interengaging electrical sockets of one aspect of the invention, with one of the sockets shown open to reveal the interior thereof, Figure 2 is a plan view of the open socket of Figure 1 interconnected at its respective opposite ends with two further identical sockets shown closed, and, Figure 3 is an enlarged view of respective busbars forming female connectors at one end of the open socket of Figure 1 engaged with respective busbars forming male connectors of an adjoining identical electrical socket, in use, at its other end.

Whilst the main aspect of the invention relates to an electrical socket which can be electrically interconnected to an identical or substantially identical socket so as to provide, with a series or row of such interconnected sockets, a variety of multiple outlets for engagement by respective electrical plugs, it will be noted that the invention also relates to a unit incorporating such an interconnected row/series of sockets, this unit being known as a power distribution unit and having an input of electrical cable to the socket at one end of the unit to supply electrical power thereto.

As shown in the drawings, a socket of the invention is generally rectangular comprising a plastics material casing having an outer cover part 10 and a

body part 11 which are interconnected together by screw means 11 a extending from the underside of the body part 11 into screw-threaded columns or the like on the inside surface of the cover part 10. At each of the longer sides of the body part 11 is a pair of spaced chamfered projections 12, which are shaped so as to clip, slide or snap-fit, in use, in a U-shaped aluminium channel, which forms a body of a power distribution unit containing a multiplicity of interconnected such sockets. The body can be of any suitable alternative shape or material which provides a robust construction.

Each cover part 10 is provided with an inlet formed as three rectangular openings 13,14 and 15 therethrough to receive the three pins of a conventional flat-pinned 13 Amp electrical plug which meets the requirements of BS 1363. As can be seen from the drawings, the openings are however arranged in the cover part 10 at an angle of 45 for a purpose to be described. It will be appreciated that the cover part 10, and its corresponding body part 11 can however be adapted for alternative forms of electrical pins, i. e. a plug with three round pins, or a plug with only two pins, either round or flat. Moreover although convenient, the arrangement of openings 13 to 15 need not be at 45 as shown but could be aligned with the casing either longitudinally or transversely.

The interior surface of the cover part 10 is formed with various moulded ribs to mount a spring loaded latch lOa, so that with no pin in the opening 13, a finger lOb of the latch projects into the opening 13 in a conventional manner.

When the plug is inserted into the socket, the Earth pin of the plug engages

against the finger to move it out of the opening 13 against the loading of spring 1 duc.

The body part 11 has various mouldings in its interior to define respective locations for respective socket contacts 13a, 14a and 15a in alignment with the respective openings 13,14 and 15, so that when the electrical plug is engaged at the cover part 10, with its pins extending through the openings 13 to 15, such pins are received in, and engaged with, the socket contacts 13a, 14a and 15a respectively. As can be seen from Figures 1 and 2 of the drawings, the socket contact 13a is aU-shaped component, preferably of bronze, with upstanding parallel arms 13b being arranged to grip the Earth pin of the plug therebetween. For each of the Neutral and Live pin socket contacts, the contact is formed by a generally conventional U-shaped bronze component with the Neutral or Live pin of the plug being received down into the Ushape which is received in an outwardly recessed moulded pocket of the body part 11. Similarly the longer Earth pin of the plug can extend into a recessed pocket below the upstanding arms 13b of the socket contact 13a. As shown in Figures 1 and 2 of the drawings, each socket contact 14a and 15a has a flat integral arm 14b, 15b respectively at one end of the U-shape of the contact, this being engaged by an abutment on the inside surface of the cover plate 10 when the cover part 10 and body part 11 are screwed together, thereby to hold each of the arms 14b, 15b in place on a moulded platform in the interior of the body part 11, and thus hold the contacts 14a and 15a themselves in place.

Respective moulded ribs upstanding from the inner face of the body part 11 define respective location channels for three brass strips in the form of

busbars 16,17 and 18 which are in electrical contact with the socket contacts 13a, 14a and 15a respectively. The locations defined by the mouldings are of generally'zig-zag'form, with each busbar being shaped to follow the shape of such channel. In particular, each busbar comprises a first straight section 19 and a second straight section 20 of substantially the same length as a section 19, the second section being parallel to the first section but out of the plane thereof. A shorter third straight section 21 of the busbar defines, with the first straight section, respective opposite ends of the busbar, with the third section being in the same plane as the first section. Connecting the first section to the second section, and the second section to the third section, are respective short angled surfaces 22,23 respectively, which slope away from the surface 20 in opposite directions but at the same side thereof.

Conveniently all three busbars are formed as pressings.

As can be seen from the drawings, the end of the section 21 for busbars 16 and 17, and section 19 for busbar 18, has a central rectangular part pressed out of its plane to define an integral tag 24 which is bent so as to lie generally parallel to the plane of the remainder of the section and define a female connector in the form of a socket or pocket therebetween, this pocket being at the side of the section remote from the section 20. Adjacent the free end of the section 19 for busbars 16 and 17, and section 21 for busbar 18, there is formed a central circular through-hole 24a.

The channels formed by the mouldings of the body part 11 are such that all three busbars are of the same shape and of identical form in relation to the tag 24 and hole 24a with the exception that for the busbar 18 the tag and hole are in the sections 19 and 21 respectively as described, whereas for the other

two busbars 16,17, the arrangement is reversed so that the tag is in each case at the end of the shorter section 21 and the hole is adjacent the end of the longer section 19 of each busbar. Moreover for the busbar 16, the angled surface 23 is formed with a through-hole. As can be seen from the drawings, this hole is to receive a rivet 25 which connects to this angled surface an end wall of the U-shaped component defining the socket contact 13a, the moulded channel for the busbar being cut-away at this location to enable this riveted connection to be disposed. Similarly for the other two busbars 17 and 18 the moulded channel in which the busbar is received is interrupted at the location of the socket contacts 14a and 15a respectively, the busbar, at each of these locations being received within the U-shaped part of the contact component.

This ensures that when the Live and Neutral pins of the electrical plug are received into the socket contacts, contact is additionally made with the busbar which carries the electrical current, as will be described. Since, in each case, the arms 14b, 15b are tightly held down, the U-shape of the component itself flexes to receive the pin, and in this regard, each pocket of the moulding in which the components 14a and 15a are received is somewhat oversized to allow for this flexing.

As can be seen from the drawings, the moulded channels for the busbars, and the lengths of the various sections of the respective busbars are arranged so that the end of each of the respective longer straight sections 19 of the busbars 16 and 17, and the end of the shorter section 21 of busbar 18 extend out of the body part 11 through openings at one shorter side thereof, i. e. the right hand side as shown in Figure 1, to form respective male connectors or pins 26. In contrast at the opposite shorter side of the body part 11, identical openings are provided, but here the respective ends of the shorter sections 21

of the busbars 16 and 17 and the end of the longer section 19 of the busbar 18 terminate flush with said openings to provide, a little way into the interior of the body part 11 respective sockets each formed by a section of the busbar together with its associated tag 24 as shown in detail in Figure 3. Each tag 24 is so formed in relation to the end moulding in which it is received that the main part of the section out of which it is formed is forced slightly out of the plane of its aligned section so that interconnection between two such sockets is possible, with the projecting three pins at the side of one socket being tightly received in the respective three'pockets'at the opposite side of the other socket so as electrically to interconnect the two sockets. In other words the male connectors or pins 26 of one socket engage with the respective corresponding female connectors of the other socket. To assist the electrical interconnection, the side of each socket from which the pins 26 project is formed with respective spaced barbs 27 which are received in respective openings 28 in the'socket'side of the other electrical socket which forms the interconnection. The engagement and release of these barbs can be by way of slightly tilting the one electrical socket relative to the other. This mechanical connection ensures that, for example during transit, the two sockets do not become disengaged accidentally. The tags 24 are preferably slightly bowed to engage the respective holes 24a of the pins received in the respective pockets.

As mentioned above, it is intended that the principle use of a socket of the invention is as part of a power distribution unit which provides an interconnected series of such sockets, with an end one of such sockets being connected to a conventional electrical cable supply, being adapted in any suitable manner if necessary. The sockets are arranged to be slidingly or

snap-fittingly engaged or clipped into a U-shaped aluminium channel or body of the power distribution unit by means of the projections 12, with adjacent sockets being electrically interconnected by virtue of the male and female connectors described above. If required the unit can also incorporate additional options such as a switch, an indicator light, a surge projection module, a fuse module for the like.

Thus with such a power distribution unit, there is no hard wiring between adjacent sockets, and this allows the height of the unit to be reduced. This is particularly advantageous as this form of power distribution unit is often used in a reduced space environment, i. e. bolted at the rear of a computer cabinet or a recess in a desk or other work station. This is in contrast to a portable extension socket unit where the height thereof is generally of little importance. Moreover the use of the interconnected sockets enables such a unit to be'custom built', i. e. with a specially selected number of sockets of a chosen type, i. e. for two or three pin plugs with the pins being either flat or round. Moreover by angling the pin plug openings at 450 as described, the leads will hang to one side of the power distribution unit when this is mounted vertically at, for example, the rear of a computer cabinet, with the whole arrangement having a lower profile than an equivalent hard wired unit.

It will be appreciated that the male connectors, i. e. the pins at one side of one unit will engage in the female connectors, i. e. the sockets at the equivalent opposite side of an adjacent identical socket with the pin engaging between the main section and the tag 24 pressed out therefrom, as shown best in Figure 3. Additionally, as described, each busbar is in electrical contact with an associated pin of the inserted plug, either by way of the upstanding arms

13b of the contact 13a which is riveted to the Earth-line busbar, or by way of the U-shaped components 14a and 15a into which the Live and Neutral pins of the plug are received so as to contact the Live and Neutral busbars respectively. It will be appreciated that the interconnection of the sockets along the power distribution unit transfer electrical supply from the cable at one end of the unit, along the busbars to the remote end socket of the unit in an efficient and effective manner. Due to the simplicity and ease of assembly and interconnection of the units, manufacturing labour costs are accordingly reduced.

In one alternative socket embodiment, the female connector is disposed outside of the openings provided in said one side of the socket, instead of being formed flush therewith. Alternatively the female connector could instead be disposed inside the socket. The connecting male pins of an adjacent socket would be correspondingly adapted.

In another alternative arrangement one socket could be formed with male connector (s) at its opposite sides respectively, to engage with respective female connector (s) of two sockets placed at respective opposite sides of said one socket respectively. Said two sockets placed at said opposite sides would each be formed with female connector (s) at its respective opposite sides.

Thus the corresponding power distribution unit would be made up of a series of interconnected sockets which are alternately male/male socket, female/female socket, male/male socket, female/female socket and so on. In a still further embodiment, the busbars 16,17 and 18 and their respective associated socket contacts 13a, 14a and 15a could be formed in one piece rather than being separate parts as shown.

Claims

CLAIMS 1. An electrical socket comprising a casing defining an inlet for reception of at least two pins of an electrical plug engageable with the socket, electrically conductive means within the casing, the pins of said plug being in electrical contact with the electrically conductive means when said plug is in engagement with the socket, in use, and said electrically conductive means defining one of a male connector and a female connector, such that said socket can be electrically interconnected, in use, by engagement of said one of said male and female connectors with the other of said male and female connectors provided by a further electrical socket.
2. A socket as claimed in Claim 1, wherein the electrically conductive means extend from a first opening at one exterior part of the casing to a second opening at another exterior part of the casing, said electrically conductive means defining a male connector at said first opening and a female connector at said second opening, such that with said further electrical socket being of the same form, said two such electrical sockets can be electrically interconnected by the engagement of said male connector of one of said electrical sockets with said female connector of the other electrical socket or vice versa.
3. A socket as claimed in Claim 2, wherein the electrically conductive means comprise a number of busbars each extending from said first opening to said second opening.

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4. A socket as claimed in Claim 3, wherein the number of busbars corresponds to said number of pins.
5. A socket as claimed in Claim 3 or Claim 4, wherein the inlet for said at least two pins is formed with an electrical socket contact for each of said pins.
6. A socket as claimed in Claim 5, wherein an earth pin socket contact is formed as a U-shaped component with upstanding arms to grip said earth pin therebetween, said component being electrically connected to a section of the busbar for said earth pin.
7. A socket as claimed in Claim 6, wherein the component is electrically connected to the busbar by a rivet.
8. A socket as claimed in Claim 6 or Claim 7, wherein said component is electrically connected to part of said busbar adjacent said female connector thereof.
9. A socket as claimed in Claim 5, wherein a neutral pin socket contact and/or a live pin socket contact is formed with a U-shaped part to receive said neutral pin or live pin of said plug, a part of the busbar associated with the pin socket contact being received in said pin socket and being engaged by said pin, in use.

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10. A socket as claimed in Claim 9, wherein the neutral pin socket contact and/or the live pin socket contact comprises an arm extending from the Ushaped part and held in position in said casing.
11. A socket as claimed in Claim 9 or Claim 10, wherein the or each of neutral pin socket contact and/or live pin socket contact is received in a moulding of the casing.
12. A socket as claimed in Claim 11 when dependent on Claim 10, wherein the arm is received on a platform of said moulding.
13. A socket as claimed in any one of Claims 3 to 12, wherein each busbar is located in a channel formed between ribs of the casing.
14. A socket as claimed in Claim 7, wherein the busbar connected to the U-shaped component forming the earth pin socket contact is located in a channel formed between ribs of the casing, said ribs being cut-away at the position of said rivet.
15. A socket as claimed in Claim 11, wherein the or each moulding interrupts a channel formed between ribs of the casing, in which channel is located the busbar, said part of which is received in said moulding.
16. A socket as claimed in any one of Claims 3 to 15, wherein said female connector is formed as a socket defined by a part of the busbar and a tag deformed therefrom.

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17. A socket as claimed in any one of Claims 3 to 16, wherein said male connector is formed by an end of the busbar.
18. A socket as claimed in Claim 4, comprising an earth pin socket contact, a live pin socket contact and a neutral pin socket contact, with the respective busbars associated with the earth and live pin socket contacts being of identical shape.
19. A socket as claimed in any one of Claims 3 to 18, wherein each busbar is a brass strip.
20. A socket as claimed in any one of Claims 3 to 19, wherein each busbar is a pressing.
21. A socket as claimed in any one of Claims 1 to 20, wherein said casing is square or rectangular and the pin plug openings defined by said inlet are together at 45 to the respective pairs of opposite sides of the casing.
22. An electrical socket comprising a casing defining an inlet for reception of at least two pins of an electrical plug engageable with the socket, electrically conductive means within the casing extending from a first opening at one exterior part of the casing to a second opening at another exterior part of the casing, the pins of said plug being in electrical contact with the electrically conductive means when said plug is in engagement with the socket, in use, and said electrically conductive means defining a male connector at said first opening and a female connector at said second opening, such that two such electrical sockets can be electrically

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interconnected by the engagement of said male connector of one electrical socket with said female connector of the other electrical socket or vice versa.
23. A power distribution unit comprising a plurality of electrical sockets as claimed in any one of Claims 1 to 22, which are electrically interconnected.
24. A unit as claimed in Claim 23, comprising a body, in which said electrical sockets are fitted by sliding, clipping or as a snap-fit.
25. A unit as claimed in Claim 24, wherein the body is U-shaped in transverse section.
26. A unit as claimed in Claim 24 or Claim 25, wherein the body is of aluminium.
27. A unit as claimed in any one of Claims 23 to 26, wherein adjacent sockets are mechanically interconnected by barbs at a side of one socket being engaged in corresponding openings in a side of an adjacent socket.
28. An electrical socket substantially as hereinbefore described, with reference to, and as shown in the accompanying drawings.
29. A power distribution unit substantially as hereinbefore described, with reference to, and as shown in the accompanying drawings.