WO2004015824A1

WO2004015824A1 - Electrical sockets in which electrical plugs are inserted to pick-up power

Info

Publication number: WO2004015824A1
Application number: PCT/ZA2003/000076
Authority: WO
Inventors: Ray Mazzullo; Toit Johan Du; Adrian Mazzullo; Graeme Eric Farsham; Frederick Jakobus Slabbert
Original assignee: Ray Mazzullo; Toit Johan Du; Adrian Mazzullo; Graeme Eric Farsham; Frederick Jakobus Slabbert
Priority date: 2002-07-31
Filing date: 2003-06-10
Publication date: 2004-02-19

Abstract

A rotary socket structure including a rotatable drum (12) is disclosed. Three electrically conductive rings (30, 32, 34) are fast in rotation with the drum and three fixed contact structures (24, 26, 28) are provided each including contacts touching the rings. The drum is rotatable with respect to the contacts and the rings. The drums slide with respect to, and maintain electrical connections to, the contacts during such rotation. The structure further includes live, neutral and earth wires (18, 20, 22) each including a metallic core and an insulating sheath, the contact structures (24, 26, 28) being attached onto said wires so that parts of the contact structures are in electrical connection with said cores.

Description

ELECTRICAL SOCKETS IN WHICH ELECTRICAL PLUGS ARE INSERTED TO PICK-UP POWER

FIELD OF THE INVENTION

THIS INVENTION relates to electrical sockets into which electrical plugs are inserted to pick-up power.

BACKGROUND TO THE INVENTION

Boxes containing a number of electrical sockets in a side-by-side array are widely used to enable a number of pieces of equipment to be plugged in and

supplied with power simultaneously.

Most plugs are of simple construction and have two or three pins. They are small enough to be plugged into the sockets of a multi-socket box without

interfering with one another. However, with the advent of equipment such as cell phones, using rechargeable batteries, the situation has changed. The plug pins now protrude in many instances from a bulky housing which contains^'a transformer, a rectifier and other components required to convert a.c. mains power to the lower voltage d.c. current needed for charging purposes.

The bulk of such a housing means that, once plugged into a socket, it can overlap an adjacent socket and prevent the adjacent socket being used. To overcome this problem it has been proposed that the sockets should be rotatable in the socket box. This enables a socket to be rotated in its box so that a bulky plug can be positioned away from an adjacent socket.

In this regard reference can be made to UK Patent Specification No. 2330700B and corresponding South African specification No. 98/9683.

The present invention seeks to provide an improved socket structure and an improved socket box which includes multiple socket structures.

BRIEF DESCRIPTION OF THE INVENTION

According to one aspect of the present invention there is provided a rotary socket including a rotatable drum, three electrically conductive rings fast in rotation with said drum, three fixed contact structures each including contacts touching said rings, the drum being rotatable with respect to said contacts and the rings sliding with respect to, and maintaining electrical connections to, said contacts during such rotation, and live, neutral and earth wires each including a metallic core and an insulating sheath, said contact structures being attached onto said wires so that parts of the contact structures are in electrical connection with said cores.

That one of the contact structures which is between the "live" wire and the "live" ring can include a switch and can further include a fuse. Said switch can be in the form of a contact that can be moved between a closed "on" position in which it bridges between two parts of the contact structure and an open "off" position in which there is a gap between itself and one of said parts.

According to a further aspect of the present invention there is provided an electrical socket box comprising a casing, at least two rotary sockets mounted in said casing for rotation about parallel but spaced axes, each socket including plug pin receiving receptacles, power supply wires extending along the casing, such wire including a metallic core and an insulating sheath, contact structures connecting the cores of said wires to said receptacles, and switch means in said contact structures between each "live" plug pin receptacle and the "live" wire.

Each "live" contact structure can include two spaced apart blades, each switch means including a contact which can be slid from an "on" position in which it bridges across said blades and an "off" position in which it is spaced from one of said blades.

Each of said live contact structures can also include a fuse cartridge, said fuse cartridge and said switch means being interlocked so that the fuse cartridge can only be removed whilst the switch is in the "off" position.

Each rotary socket can include a rotatable drum, there being three electrically conductive rings fast in rotation with said drum and three fixed contact structures each including contacts touching said rings, the drum being rotatable with respect to said contacts and the rings sliding with respect to, and maintaining electrical connections to, said contacts during such rotation. By providing two sets of live, neutral and earth wires, and connecting some of the rotary sockets to one set of wires and other of the rotary sockets to the other set of wires, it is possible to provide normal mains power and "clean" (dedicated) power for computers and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present 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 pictorial view of a rotary socket;

Figure 2 is a pictorial view of the live contact structure of the rotary socket in its open "off" condition;

Figure 3 is a pictorial view of the contact structure of Figure 2 in its closed "on" position;

Figure 4 is a pictorial view of the neutral contact structure of the rotary socket;

Figure 5 is a pictorial view of the earth contact structure of the rotary socket;

Figure 6 is a top plan view of the rotary socket;

Figure 7 is an elevation showing a fuse cartridge in a first position;

Figure 8 is a similar view showing a fuse cartridge close to its final position;

Figure 9 is a side elevation showing the fuse cartridge in its fully inserted position and with a switch in its "off" position;

Figure 10 is a similar view showing a switch in its "on" position;

Figure 11 is a top plan view of the rotary socket with plastic parts omitted and the switch in its "off position;

Figure 12 is a view similar to Figure 11 but showing the switch in its "on" position;

Figure 13 is a pictorial view of the rotary socket but with plastic parts omitted and with the live contact structure in the open, "off" position;

Figure 14 is a view taken from the opposite side to Figure 13 but showing the live contact structure closed and hence "on";

Figure 15 is a view similar to Figure 14, and having the switch in the "off" position;

Figures 16 and 17 are diagrammatic pictorial views from opposite directions of the. fuse cartridge and the switch, the switch being shown in the "off" position'

Figures 18 and 19 are diagrammatic views similar to those of Figures 16 and 17 and showing the switch in the "on" position; and

Figure 20 is an "exploded" view of the components of a drum of the rotary socket.

DETAILED DESCRIPTION OF THE INVENTION

The rotary socket 10 illustrated in Figure 1 comprises a rotatable drum generally designated 12 which has plug pin openings 14 in a top cover 16 thereof. Fixed, live, neutral and earth wires 18, 20, 22 are connected by contact structures 24, 26 and 28 to conductive rings 30, 32, 34 fast in rotation with the drum 12. Each wire 18, 20, 22 comprises a metallic core and an insulating sheath.

The contact structure 24 shown in Figures 2 and 3 comprises a fixed contact 36 which has tabs that are crimped onto the wire 18. A short length of the insulating sheath of the wire 18 is removed so that the tabs touch the metal core of the wire 18.

A sliding contact 38 is free to move on a blade 40 forming part of the

contact 36. The contact 38 comprises two parallel leaves 42 and 44 joined at their upper ends by a sleeve 46 which is almost completely circular in cross section. The arrangement is such that when the leaves 42, 44 are forced apart to allow the blade' 40 to be inserted between them, the sleeve 46 is resiliently deformed and exerts a restoring force which presses the leaves 42, 44 against opposite sides of the blade 40.

The contact structure of Figures 2 and 3 further includes a pair of fuse holders 48 and 50 which carry a fuse 52. Between the fuse holder 50 and the ring 30 there is a fixed contact 54. At its outer end the contact 54 is bent into a generally U- shaped section 56, the two limbs of which resiliently grip a blade 58 forming part of the fuse holder 50. At its radially inner end the contact 54 is punched and then deformed to provide a central upper tab 60 and two lower tabs 62. The tab 60 is in contact with the top surface of the ring 30 and the tabs 62 are in contact with the lower surface of the ring 30. The deformation of the tabs 60, 62 results in a gripping action being exerted on the ring 30 by the tabs 60, 62 so that electrical contact is made whilst, however, permitting the ring 30 to rotate with respect to the tabs 60, 62.

Internally the ring 30 is formed with a series of notches 64 and is extended inwardly to provide an integral plug pin receptacle 66.

The fuse holder 48 is formed with a blade 68 which is aligned with the blade 40. In the position illustrated in Figure 2 the sliding contact 38 is clear of the blade 68 and the "live" circuit is thus open and no power is supplied to the ring 30. In Figure 3 the contact 38 has been slid to the position in which it bridges across the blades 40 and 68. Thus power is supplied through the fuse holders 48, 50, the fuse . 52, fixed contact 54 and tabs 60, 62 to the ring 30.

The ring 32 (Figure 4) is shown as being connected to the wire 20 by a contact 70 which constitutes the contact structure, 26. The contact 70 bridges directly from the neutral wire 20 to the ring 32 as it is not necessary to fuse this circuit or ' provide any way in which it can be opened or closed. Apart from this difference, the structure of Figure 4 is similar to the structure of Figures 2 and 3 and, where applicable, like parts have been designated with like reference numerals with the addition of the suffix .1.

In Figure 5 the "earth" circuit is illustrated. A contact 72 constitutes the contact structure 28 and is crimped onto the wire 22. In the same way as the contact 70 does, the contact 72 bridges directly from the wire 22 to the ring 34. Those parts in Figure 5 which correspond to the parts in Figures 2 and 3 have been designated with the same reference numeral plus the suffix .2. It will be noted that the ring 34 is not notched. A telltale light in the form of a neon 74 (see Figures 1 , 6 and 11 etc.) is provided for showing that the contact 38 has been moved to the position in which it bridges between the blades 40 and 68 and that power is thus being supplied to the socket. The flying contact wires of the neon 74 are connected one to the contact 54 and the other to the contact 70.

The fuse holders 48 and 50 are secured to a base 79 of insulating material thereby to form a fuse cartridge 76. The cartridge 76 is located by inserting the blade 58 into the section 56 and then sliding the contact 38 onto the blade 68 using a switch operating arm 84 (see Figures 7 etc.).

A lid 92 closes-off the entrance to the space in the casing 78 which receives the fuse cartridge 76. Columns 93 extending downwardly from the lid 92 presses on a base 79 and prevents the cartridge 76 from moving.

To remove the cartridge 76 it is necessary to open the switch 84 by sliding the contact 38 away from the blade 68. This releases the blades 68 which is otherwise locked in place.

On the underside of the lid 92 there is a latch element 94 which is mounted on a pivot 96 accessible from above the lid 92. When the lid 92 is closed, the ends of the latch element 94 are in sockets provided therefor in the main casing 78. To open the lid 92, the element 94 is turned so that its ends move out of the sockets. Two shallow recesses (not shown) are provided in the upper surface of

the cartridge 76 adjacent the lid 92, the recesses being at opposite ends of the lid 92 along the lid's longitudinal axis.

Turning finally to Figure 20, the drum 12 comprises a main cylindrical body 98 having a transverse partition 100 with openings 102 in it for the receptacles 66, 66.1, 66.2. A shutter 104 and a shutter return spring 106 are provided between the partition 100 and the cover 16. One end of the leaf spring 106 is located by two posts 108 and the shutter rotates on a pivot 110.

Externally the body 98 has splines 112 with gaps in them. The live ring 30 is slid on the body 98 from the lower end thereof with the splines 112 in the notches 64. The splines terminate just below a top rim 114 of the body 98. Once the ring 30 is immediately below the rim 114, it can be turned through a short distance to misalign the notches 64 and the splines 112 and prevent the ring 30 moving back down the body. Likewise the ring 32 is slid onto the body 98 until it is aligned with intermediate gaps in the splines 112. It is then rotated to misalign its notches 64.1 and the splines 112 and lock the ring 32 in place.

A base 116 snap fits into the body 98 and grips the ring 34 between itself and the body 98. Posts 118, 120, 122 upstanding from the base 116 locate and support the receptacles 66, 66.1 , 66.2 so that they cannot move downwardly when the pins of a plug are inserted through the openings 14. If a second set of wires 18, 20, 22 is run along the other side of the box, and some of the sockets 10 are connected to these, it is possible to provide normal mains power and also "clean" (dedicated) power for computers and the like.

In Figure 7, a second set of wires 18.1 , 20.1 , 22.1 are shown extending through the casing 78. These are the "clean" (dedicated) power wires. Dedicated sockets 10 can be connected to these by appropriately positioning the contact structures of these sockets so that they pick up power from the wires 18.1 , 20.1, 22.1 instead of from wires 18, 22 and 22.

Claims

CLAIMS:

1. A rotary socket including a rotatable drum, three electrically conductive rings fast in rotation with said drum, three fixed contact structures each including contacts touching said rings, the drum being rotatable with respect to said contacts and the rings sliding with respect to, and maintaining electrical connections to, said contacts during such rotation, and live, neutral and earth wires each including a metallic core and an insulating sheath, said contact structures being attached onto said wires so that parts of the contact structures are in electrical connection with sajd cores.

2. A rotary socket as claimed in claim 1 , wherein that one of said contact structures which is between the "live" wire and the "live" ring includes a switch and a

fuse.

3. A rotary socket as claimed in claim 2, wherein said switch is in the form of a contact that can be moved between a closed "on" position in which it bridges between two parts of the contact structure and an open "off" position in which there is a gap between itself and one of said parts. -■

4. An electrical socket box comprising a casing, at least two rotary sockets mounted in said casing for rotation about parallel but spaced axes, each socket including plug pin receiving receptacles, "live" and "neutral" power supply wires extending along the casing, each such wire including a metallic core and an insulating sheath, contact structures connecting the cores of said wires to said receptacles, and switch means between each "live" plug pin receptacle and the "live" wire.

5. An electrical socket box as claimed in claim 4, wherein each "live" contact structure includes two spaced apart blades and each switch means includes

a contact which can be slid from an "on" position in which it bridges across said blades and an "off" position in which it is spaced from one of said blades.

6. An electrical socket box as claimed in claim 4, wherein each live contact structure includes a fuse cartridge, said cartridge and said switch means being interlocked so that said cartridge is only removable whilst the switch is in the "off" position.

7. An electrical socket box as claimed in claim 4, wherein each rotary socket includes a rotatable drum, there being three electrically conductive rings fast in rotation with said drum and three fixed contact structures each including contacts touching said rings, the drum being rotatable with respect to said contacts and the rings sliding with respect to, and maintaining electrical connections to, said contacts during such rotation.

8. An electrical socket box as claimed in claim 4, wherein said socket box includes two sets of live, neutral and earth wires, some of the rotary sockets being connected to one set of wires and other rotary sockets to the other set of wires thereby to permit normal mains power and "clean" (dedicated) power for computers and the like to be provided.