GB2229588A

GB2229588A - Electrical connector

Info

Publication number: GB2229588A
Application number: GB9003728A
Authority: GB
Inventors: Mcarthur * Ralston Archibald
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-02-18
Filing date: 1990-02-19
Publication date: 1990-09-26
Anticipated expiration: 2010-02-19
Also published as: GB2229588B; GB9003728D0

Abstract

A plug 1 is wired by pushing the wires 15 of a cable 14 through apertures 4 in the body 2 of the plug 1 and pressing upon fixing devices 7 which secure the wire 15 in place. The fixing device 7 may also retain plug pins 3. The pins may be provided with slotted insulation displacement contacts e.g. 110b (fig. 9). A hinged flap 6 and U-shaped chamber 5 form an external cable clamp. <IMAGE>

Description

"Electrical Connector" This invention relates to an electrical connector.

The conventional three-pin electrical plug is an indispensable part of modern life, serving as an electrical connector for many appliances. However, such plugs do have their drawbacks: fitting them to a cable is time-consuming and complicated, often involving different types of screwdriver and awkward manipulation of the conductors into the plug terminals. These operations may be difficult for the elderly or less dexterous and, once fitted, there is also danger of the wires working loose.

According to the present invention, there is provided an electrical connector comprising a hollow body containing at least one terminal, the body having at least one aperture for receiving a conductor, guide means in the body for directing a conductor inserted through the aperture into engagement with the terminal internally of the body, and a fixing device for the or each terminal actuable from outwith the body to fix the conductor in electrical contact with the terminal.

Preferably, the connector is a plug and each terminal is in circuit with a pin extending from the body.

Most preferably, said fixing device is coterminous with the wall of the body once in its fixing position.

Preferably also, a plurality of apertures is provided, one for each conductor in a cable for directing each conductor into a respective guide means and thus into engagement with a respective terminal.

Preferably, the or each terminal comprises an electrically conductive blade member, and the conductor is held in contact with the blade member by the fixing means.

Preferably, said conductor is insulated and upon arrival at the blade member the action of positioning the fixing device internally forces the conductor between the blade member and the fixing device, so cutting through the insulating material and providing a means of electrical connection with the blade member.

Preferably, the or each pin is fitted through the body so as to be axially moveable until locked in position by actuation of said fixing device shaped to resist unlocking movement.

Preferably, said fixing device is actuable in a single operation from the outside of the body and, once actuated is flush with, or recesses into, the wall of the body and locked against removal.

Preferably, said body has an external means of securing the cable externally of the aperture. For example, a hollow tube or a U-shaped channel with a hinged flap may be provided.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: Fig. 1 is a perspective view of a 13A plug forming an electrical connector in a first embodiment of the present invention; Fig. 2 is a plan view of the plug of Fig. 1 with the top removed; Figs. 3A and 3B are respectively a side view and a perspective view of a neutral pin assembly of the plug of Fig.l; Figs. 3C and 3D are similar views of an earth pin assembly; Figs. 3E and 3F are similar views of a live pin assembly; Fig. 4 is an exploded perspective view of the earth pin assembly of Fig. 3 and an associated fixing device; Fig. 5 is a perspective view of the plug of Fig. 1 before attachment to a cable;; Figs. 6a, 6b and 6c are respectively a front view, a side view and a perspective view of an earth pin assembly in a second embodiment of the invention; Figs. 7a, 7b and 7c are respectively a side view, a front view and a perspective view of a neutral pin assembly in the embodiment of Fig. 6; Figs. 8a and 8b are respectively a side view and a front view of a live pin assembly (minus the fuse bracket section) in the embodiment of Fig. 6; Fig. 8c is a perspective view of the live pin assembly of Figs 8a and 8b with its fuse bracket; Fig. 8d is a side view of the fuse bracket section of Fig. Sc section; and Fig. 9 is an exploded perspective view of the earth pin assembly of Fig. 6 and its associated fixing device; and Fig. 10 is an exploded perspective view of an earth pin assembly and its associated fixing device in a third embodiment of the invention; Fig. 11 is a view of the embodiment of Fig. 10 with a wire positioned ready for engagement; and Fig. 12 is a perspective view of the earth pin assembly and part of the fixing device of Fig. 10 in engagement without a wire.

As seen in Fig. 1, the electrical connector of the present embodiment is in the form of a 13A plug 1 of British Standard type, and comprises a hollow body 2 from which extend three pins 3 (only two of which are seen in Figs 1 and 5). Fig. 1 shows the plug 1 serving as termination for a flexible cable 14 having insulated conductors 15a, 15b and 15c. The cable 14 is secured relative to the plug 1 by a flex grip comprising a channel 5 and a movable flap 6 latchable therein. The conductors 15 extend through apertures 4 into respective guides 8a, 8b, Sc (Fig. 2) for electrical connection with the pins 3.

Referring to Fig. 3, each pin 3 is in electrical connection with a respective blade member 10. In the case of the neutral pin 3a and the earth pin 3b, the blade members lOa, lOb are formed as part of a channel section directly secured (eg by welding) to the head of the pin. The live pin 3c is in circuit with its blade member lOc via a cartridge fuse 9.

Each blade member 10 is formed with a converging slot 11.

The blade members 10 coact with fixing devices 7 (see especially Fig. 4) each comprising a plastics block serrated at 12 on opposed vertical faces and defining a vertical slot 13 of a width to accept the blade member 10.

Fig. 5 shows the plug 1 before it has been fitted to the cable 14, with its fixing devices 7 raised above the body 2 of the plug 1, ready to be pushed into place.

The plug 1 is fitted onto the cable 14 as follows. The cable 14 is placed against the body 2 so that each of the three wires 15a, I5b and 15c may be cut to a length corresponding to the distance from the apertures 4 to its respective pin 3. The cable 14 is positioned in the channel 5 (Fig 1) and each of the wires 15a, 15b and 15c is manually pushed through its respective aperture 4 and so into its individual guide 8 and on to its blade member 10 where it rests upon the slot 11. The fixing device 7 is now pushed down into the body 2 so that it is flush with the surface, and firmly held within the body 2 by the action of the serrated edges 12. The guide 8 is spaced from the blade member 10 to define a gap for the fitment of the fixing device 7 over the wire 15 and blade member 10.This action results in the wire 15 being forced down into the slot 11, which cuts through the insulation of the wire 15 and provides an electrical connection. At the same time, the wire 15 is secured on either side of the groove 11, because its insulation is still present on either side of the slot 11, and the fixing device 7 both encloses the blade member 10 and the wire 15, and secures the pin 3 against the body 2 so that it too may not move. This position thus provides an enclosed, insulated and secure electrical connection.

The flap 6 is then positioned over the cable 14 so securing it in place.

A second embodiment of the plug is shown in Figs 6-9.

The features of this embodiment which are the same as the first have corresponding reference numbers, and those which are modified have the reference number plus 100 ie 10 ,becomes 110. The second embodiment has modified blade members 110 and fuse bracket 17 as shown in Figs 6-8. The blade members 110 are now continuous with the pins 3 and the shape of the neutral and live blade members 110a and llOc are further changed by angling 16 so that the wires (not shown) can run directly into the slot 11. In this embodiment, the fuse (not shown) is held within its bracket 17 so that, in conjunction with a removable section (not shown) of the body the fuse may be changed without dismantling the plug 1.

Fig. 9 demonstrates that the fixing device 7 still coacts with the blade members 110 in the same way as in the first embodiment.

A third embodiment of the fixing device of the plug is shown in Figs. 10-12. Modified features of this embodiment are numbered as in the first embodiment plus 200 ie 7 becomes 207. A fixing device 207 is fitted with a spring 18 and gripping member 19 which provide a slot 213. The gripping member 19 is spring-loaded into the body of the fixing device and shaped to embrace the blade member 210 (Fig. 12).

The slots 213, 211 engage to grip a wire 215 firmly between them.

This embodiment may receive wires of different diameter as the V-shape of the slots ensures that the width of space 20 between them varies depending on the depth to which the spring-loaded gripping member embraces the blade member 210.

The spring 18 thus provides a range of positions of the gripping member in which the wire is securely fastened.

It is apparent that this invention gives several advantages over the conventional electrical connectors available, for example the three-pin plug. It may be adapted for one-, two or three-pin plugs and for other forms of connector (eg sockets) but, in any case, the invention may be used quickly and easily in a one-step operation. Once fitted, the electrical contact is firmly secured within the fixing device, thus preventing the cable from working its way loose and so becoming dangerous.

A further safety aspect of this invention is that an electrical connection is only provided when the fixing device is flush with the top of the body, which must itself be firmly in place. If contact is not made because, for example, the fixing device is not pushed down firmly or far enough, or the top half of the plug is loose or absent, the pins will not be held securely inside the body of the plug and so cannot be connected with the socket. A further modification of the fixing device, such as a lever, may be included to allow less dexterous persons to position it correctly.

The guiding means may be moulded channels or enclosed tunnels that may encase the wire and so provide a completely insulated connection once the fixing device is in place.

These channels may be constructed so as to avoid the necessity of cutting down the wires before fitting th plug, eg they may be extended to equal lengths. Surface marks could be included on the body to indicate the length of each wire required. If identifying marks were also put on the wires themselves, such plugs could be used by people with defective vision.

The neck of the plug provides an extra gripping action securing the cable in relation to the apertures, so avoiding unnecessary wear of the cable. The connector of the invention may be made watertight by the addition of gaskets, thus allowing immersion in water.

If it is necessary to remove the plug from the cable or change the fuse, this may be done in the usual way by removing the top. Alternatively, the plug may be modified to allow changing the fuse without dismantling the whole piug.

A number of materials may be used for the body eg plastics, rubber, and the fixing device may be of the same or different material and may be coloured to highlight its position. The fixing device may have a serrated edge as shown or some other means of securing it over the blade member and within the body.

The invention therefore provides a safe and easy method of fitting a plug in seconds, and may be cheaply manufactured with iow capital investment.

Modifications and improvements may be added without departing from the scope of the invention.

Claims

1. An electrical connector comprising a hollow body containing at least one terminal, the body having at least one aperture for receiving a conductor, guide means in the body for directing a conductor inserted through the aperture into engagement with the terminal internally of the body, and a fixing device for the or each terminal actuable from outwith the body to fix the conductor in electrical contact with the terminal.

2. An electrical connector as claimed in Claim 1, wherein the electrical connector is a plug and each terminal is in circuit with a pin extending from the body.

3. An electrical connector as claimed in Claim 1 or Claim 2, wherein said fixing device is co-terminous with the wall of the body once in its fixing position.

4. An electrical connector as claimed in any of the preceding Claims, wherein a plurality of apertures is provided, one for each conductor in a cable, for directing each conductor into a respective guide means and thus into engagement with a respective terminal.

5. An electrical connector as claimed in any of the preceding Claims, wherein the or each terminal comprises an electrically conductive blade member, and the conductor is held in contact with the blade member by the fixing means.

6. An electrical connector as claimed in Claim 5 wherein said conductor is insulated and upon arrival at the blade member the action of positioning the fixing device internally forces the conductor between the blade member and the fixing device, so citing through the insulating material and providing a means of electrical connection with the blade member.

7. An electrical connector as claimed in Claim 2 or in any of Claims 3-6 when dependent on Claim 2, wherein the or each pin is fitted through the body so as to he axially moveable until locked in position by actuation of said fixing device shaped to resist unlocking movement.

8. An electrical connector as claimed in any of the preceding Claims, wherein said fixing device is actuable in a single operation from the outside of the body and, once actuated, is flush with, or recesses into, the wall of the body and locked against removal.

9. An electrical connector as claimed in any of the preceding Claims, wherein said body has an external means of securing the cable externally of the aperture.

10. An electrical connector as claimed in Claim 9 wherein said external means is provided as a hollow tube.

11. An electrical connector as claimed in Claim 9 wherein said external means is provided as a U-shaped chamber with a hinged flap.

12. An electrical connector substantially as hereinbefore described with reference to the accompanying drawings.