GB2098812A

GB2098812A - Electrical plugs

Info

Publication number: GB2098812A
Application number: GB8206409A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-03-19
Filing date: 1982-03-04
Publication date: 1982-11-24
Also published as: GB2098812B

Abstract

An electrical plug which is convenient to assemble has a cover which is slidable over the connection pins and may be press-fastened onto the base. The plug may have coloured markings for visually indicating which wire has to go to which connection pin. The cable wires may be held captive in the apertures between the side of the pins and the cover. Alternatively, a cable entry and retaining means may be provided as an integral part of the cover and/or base, or a resiliently biassed member or two separate members may be provided near the cable entry for gripping the cable wires. The base may also have locating means between the cable entry and each pin for accommodating cable wires, or separate members may be provided for gripping an individual cable wire and insertion in a connection pin.

Description

SPECIFICATION Electrical plugs The present invention relates to electrical plugs, particularly for use with domestic and similar appliances.

Electrical plugs are fitted to cables running from wall sockets to appliances such as cookers, kettles, heaters, hair-dryers and radios. It is often awkward and more time-consuming than expected to fit conventional plugs, especially for the elderly and disabled, because placing the wires in their correct positions in the plug is both fiddly and tricky. A person fitting the plug often does not know which of the wires from the cable is supposed to go to which of the socket connection pins in the plug.

Furthermore it is often difficult to locate the cable in the entry recess provided in a conventional plug and to dispose the cable wires in the plug so that the bared ends of the wires are securely seated in brass connections to the external socket pins to effect a good electrical connection and so that also the cable wires do not extend outwardly of the plug from the entry recess.

In a conventional plug, the bared ends of the wires located in the brass connections must be screwed down and the plug cover is also screwed to the plug base housing the wire connections and pins, thus requiring employment of a screwdriver and screw which can be dropped and/or lost.

It is an object of the invention to obviate these disadvantages and to provide an electrical plug which can be readily fitted and changed.

According to a first aspect of the invention, I propose an electrical plug comprising a base, a plurality of pins located in the base for connection with a socket connected with a source of electricity, a cover matingly securable with the base and a cable entry, the cover having a plurality of apertures therethrough each for receiving a different one of the connection pins such that the cover is slidable over the pins and the bared ends of cable wires can be each held captive between the side of each aperture and each pin to effect an electrical connection.

According to a second aspect of the invention, I propose an electrical plug comprising a base, a plurality of pins moated in the base for connection with a socket connected with a source of electricity, a cover matingly securable with the base, a cable entry and retaining means integral with one or both of the cover and the base for engagement with cable wires near the cable entry so as to hold the cable wires captive.

According to a third aspect of the invention, I propose an electrical plug comprising a base, a plurality of pins located in the base for connection with a socket connected with a source of electricity, a cover matingly securable with the base and a cable entry with two members near the cable entry for holding cable wires captive therebetween.

According to a fourth aspect of the invention, I propose an electrical plug comprising a base, a plurality of pins located in th base for connection with a socket connected with a source of electricity, a cover matingly securable with the base and a resiliently baissed member near the cable entry for holding cable wires captive thereunder.

According to a fifth aspect of the invention, I propose an electrical plug comprising a base, a plurality of pins located in the base for connection with a socket connected with a souce of electricity, a cover matingly securable with the base and a cable entry, the base having locating means between the cable entry and each pin for accommodating cable wires.

According to a sixth aspect of the invention, I propose an electrical plug comprising a base, a plurality of pins located in the base for connection with a socket connected with a source of electricity, a cover matingly securable with the base, a cable entry and coloured markings corresponding to the colours of cable wires for visually indicating the paths from the cable entry for the cable wires.

According to a seventh aspect of the invention, I propose an electrical plug comprising a base, a plurality of pins located in the base for connection with a socket connected with a source of electricity, a cover matingly securable with the base, a cable entry and a plurality of gripping members for each gripping a cable wire and for insertion into a different one of the connection pins.

Electrical plugs having these improvements are especially straightforward and convenient to fit onto the ends of cables e.g. from domestic appliances. The'/ can therefore be fitted with a considerable saving in time and labour and such plugs are particularly helpful for elderly and disabled people.

Several embodiments of the invention are described by way of example with reference to the drawings, in which;- Figure 1 is a diagramma-tic side view of a plug showing a cover having apertures according to a first aspect of the invention; Figure 2 is a diagrammatic side view of a cover as shown in Fig. 1; Figure 3 is a diagrammatic view of a plug as shown in Fig. 1 also showing a bolting means for securing phe cover and the base together; Figure 4 is a detailed view 88 the bolting means for the plug as shown in Fig. 3; Figure 5 is a diagrammatic view showing an alternative cover; Figure 6 is another view of the cover shown in Fig. 5 and shows the seating of the pins in the plug;; Figure 7 is a diagrammatic view of a plug having a projection at the cable entry according to a second aspect of the invention; Figure 8 is a detailed view of the projection shown in Fig. 7; Figure 9 shows an alternative cable entry projection; Figure 10 is a diagrammatic plan view showing a base of an electrical plug having a cable entry according to a third aspect of the invention; Figure 11 is a diagrammatic side view of a cable entry to the base shown in Fig. 10; Figure 12 is a diagrammatic side view of a plug having a cable entry as shown in Fig.

10; Figure 13 is a diagrammatic view of a hinge of a plug as shown in Fig. 12; Figure 14 is a diagrammatic view of an alternative cable entry according to a fourth aspect of the invention; Figure 15 is a diagrammatic side view of another cable entry according to a fourth aspect of the invention; Figure 16 is a diagrammatic view of another cable entry; Figure 1 7 is a diagrammatic view showing a base of an electrical plug according to a fifth aspect of the invention; Figure 18 is a diagrammatic view showing the wire-housing means of Fig. 1 7 in detail; Figure 19 is a diagrammatic side view showing channels in the base; Figure 20 is a detailed diagrammatic view of a wire-receiving means according to seventh aspect of the invention; and Figure 21 is a diagrammatic plan view of a plug in which the ends of the wires are each held in a member as shown in Fig.20.

Referring to the drawings, an electrical plug has a base 1 having neutral, earth, false and live pins 2, 3, 4, 5 respectively, a cable entry 6 for a cable 7 having earth, live and neutral wires 8, 9 and 10 and a cover 11 to cover the base including bared ends of the wires.

The B.S. colour code for the wires is: Brown = Live; Blue = Neutral; Green/Yel low = Earth. Each of the wires is connected respectively to pins, 2, 3 and 4 and is stripped at the end generally by about 1-2 cm for connection to the respective pin.

A first embodiment has a cover 11 having three apertures 1 2 for each receiving one of the connection pins 2, 3 and 4 and the stripped ends of the cable wires can be each held captive between the sides of each aperture and each pin. The plug is shown in Figs.

1 to 4; but only two of the three apertures in the cover are illustrated in the drawings. The earth, neutral and false pins may be split for each receiving the respective one of the wires.

However, the live pin should not be split to avoid the user connecting a wire thereto instead of the false pin and fuse.

The cover may thus be pressed over the pins onto the base. The cover and the base may be secured together by a bolt 13, as shown in Fig. 4. The bolt is knurled at one end for finger-gripping and externally threaded at the other end which passes through a longitudinal aperture 14 in the plug base and can be screwed into an internallythreaded member 15, which may also be externally knurled at one end. The cover is snap-fitted between the knurled members.

The knurled end of the bolt can conveniently be screwed by hand and/or further tightened with a coin; thus, the need for a screwdriver and/or screws is obviated. The bolt may be composed of a plastics material. Alternatively, as shown in Figs. 5 and 6 the cover may extend over the sides of the base. The cover may be secured to the base by two coin tightened screws 16. The pins have two lateral projections 1 7 at the bottom for holding the pins in the base. They are inserted into apertures 1 8 in the base and turned through 90 on projections 1 9 serving as pivots so that the lateral projections engage in undercut slots 20.

As also shown, a fuse 21 is seated in a recess 24 and is externally exposed to allow exchanging the fuse 22 without removing the cover from the base. The fuse is located between the live pin and the false pin, which is small and does not project out of the plug; the fuse is connectible to each by conductive, resilient clips 23. In the alternative shown in Figs. 5 and 6, the fuse is held in place beneath the live and fuse pins and the live pin must be angularly moved so as to allow the fuse to be replaced.

As shown in Figs. 7 and 8 the cable at the cable entry is held down by a lug 24 projecting from the cover 1. The lug is received in a recess 25 complementarily shaped to lug 24 in the base; the cable wires are tightly trapped in the recess by the lug. An alternative securing means is shown in Fig. 9 in which the cover 11 has a projecting recess 26 which tightly covers the cable. This is particularly useful for preventing children being able to meddle with the plug by pulling the cable out.

As shown in Figs. 10 and 11 a member 27 over which the sheathed wires may be passed extends across the cable entry. Between the member 27 and the pins there is a second similar member 28 under which the wires are passed.

The first member 27 may be part of a hinge 29 between the base 1 and the cover 11. The hinge can be fastened by a spindle 30 having a threaded end which is co-operable with a threaded aperture in the hinge as shown in Figs. 1 2 and 13; the spindle is conveniently externally slotted so that it may be screwed by means of a coin.

Referring to Fig. 14 an alternative cable entry has a longitudinal member 28 beneath which sheathed cable wires 8, 9 and 10 are passed. A pair of enclosed springs 31, each act on a different one of the two ends of the member 28 to hold it down. The member may be released by pressing it upwardly and the wires 8, 9 and 10 may then be removed.

Another cable entry is shown in Fig. 1 5 having two members 27 and 28 for holding wires therebetween, of which the one member 28 is fixed, with springs 31 for resiliently biassing the other member. Conveniently, the members 27 and 28 may be of cylindrical shape. The member 27 holds the wires 8, 9 and 10 firmly against the member 28. As shown in Fig. 16, an indentation 52 in the cover 11 is located (when the plug is ready for use) between both members 27 and 28 and the cable entry 6, for preventing the member 27 disengaging with the wires and for holding all the wires in place. As shown in Fig. 5, another alternative wire clamping means is that of three projections 32, each one holding a different one of the wires in place.

Referring now to Figs. 17, 1 8 and 1 9 three tubes 33 run along the base from the cable entry 6 to each pin 2, 3 and 4. Each wire may be pushed through a tube from the cable entry to the respective pin and secured to the respective pin. An alternative means of housing the wires is shown in Fig. 19: the wires may be each seated in one of three channels 34 in the plug base. The tubes may be transparent so that the colours of the wires show through or they may be coloured according to the B.S. colours of the wires so that it is evident which must be secured to which pin. Alternatively, coloured lines may be marked on a conventional base or in the channels.

A member 35, is shown in Fig. 10 having two fingers with mating, serrated edges for gripping the stripped end of a cable wire.

Each gripping member can be easily pushed into a pin connection 2, 3 or 4 as shown in Fig. 1 2. The gripping member may be coloured according to the B.S. system for each pin.

The plug according to the invention can be moulded from non-conductive, hard PVC or rubber/rubberised material.

Claims

1. An electrical plug comprising a base, a plurality of pins located in th base for connection with a socket connected with a source of electricity, a cover matingly securable with the base and a cable entry, the cover having a plurality of apertures therethrough each for receiving a different one of the connection pins such that the cover is slidable over the pins and the bared ends of cable wires can be each held captive between the side of each aperture and each pin to effect an electrical connection.

2. A electrical plug according to claim 1, wherein the cover may be press-fastened onto the base.

3. An electrical plug according to claim 1 or claim 2, wherein the cover extends over the side of the base.

4. An electrical plug according to claims 1, 2 or 3, wherein the cover and the base are securable together by a bolt.

5. An electrical plug according to any one of claims 1 to 4, wherein a fuse is seated in the plug and is externally exposed so as to allow it to be removed from the plug without also removing the cover.

6. An electrical plug comprising a base, a plurality of pins located in the base for connection with a socket connected with a source of electricity, a cover matingly securable with the base, a cable entry and retaining means integral with one or both of the cover and the base for engagement with cable wires near the cable entry so as to hold the cable wires captive.

7. An electrical plug according to claim 6, wherein the retaining means comprises a lug on the cover which can be received in a recess in the base with a cable wire therebetween.

8. An electrical plug according to claim 6, wherein the retaining means comprises a projecting recess in the cover for covering a cable wire.

9. An electrical plug comprising a base, a plurality of pins located in the base for connection with a socket connected with a source of electricity, a cover matingly securable with the base and a cable entry with two members near the cable entry for holding cable wires captive therebetween.

1 0. An electrical plug according to claim 9, wherein one of the members is fixed and the other member is releasable.

11. An electrical plug comprising a base, a plurality of pins located in the base for connection with a socket connected with a source of electricity, a cover matingly securable with the base and a resiliently biassed member near the cable entry for holding cable wires captive thereunder.

1 2. An electrical plug according to claim 11, wherein the resilient bias comprises one or more enclosed springs.

1 3. An electrical plug comprising base, a plurality of pins located in the base for connection with a socket connected with a source of electricity, a cover matingly securable with the base and a cable entry, the base having locating means between the cable entry and each pin for accommodating cable wires.

14. An electrical plug according to claim 13, wherein the locating means comprises a tube.

1 5. An electrical plug according to claim 13, wherein the locating means comprises a channel.

16. An electrical plug comprising a base, a plurality of pins located in the base for connection with a socket connected with a source of electricity, a cover matingly securable with the base, a cable entry and coloured markings corresponding to the colours of cable wires for visually indicating the paths from the cable entry for the cable wires.

1 7. An electrical plug according to claim 16, wherein the coloured markings are lines running from the cable entry to each connection pin.

1 8. An electrical plug comprising a base, a plurality of pins located in the base for connection with a socket connected with a source of electricity, a cover matingly securable with the base, a cable entry and a plurality of gripping members for each gripping a cable wire and for insertion into a different one of the connection pins.

1 9. An electrical plug according to claim 19, wherein the gripping member comprises two fingers having mating, serrated edges for gripping the stripped end of a cable wire.

20. An electrical plug according to any preceding claim, having earth, neutral and live pins which are split for each receiving a cable wire.

21. An electrical plug according to any preceding claim, wherein the cover and the base are securable together by one or more coin-turnable screws.

22. An electrical plug according to any preceding claim, wherein the connection pins have lateral projections for engagement with undercut slots in the base.

23. An electrical plug constructed and arranged substantially as herein described with reference to and as illustrated in Figs. 1 to 4 of the drawings.

24. An electrical plug constructed and arranged substantially as herein described with reference to and as illustrated in Figs. 5 and 6 of the drawings.

25. An electrical plug constructed and arranged substantially as herein described with reference to and as illustrated in Figs. 7 and 8 of the drawings.

26. An electrical plug constructed and arranged substantially as herein described with reference to and as illustrated in Fig. 9 of the drawings.

27. An electrical plug constructed and arranged substantially as hereinbefore described with reference to and as illustrated in Figs. 10 to 1 3 of the drawings.

28. An electrical plug constructed and arranged substantially as herein described with reference to and as illustrated in Fig. 14 of the drawings.

29. An electrical plug constructed and arranged substantially as hereinbefore described with reference to and as illustrated in Fig. 1 5 of the drawings.

30. An electrical plug constructed and arranged substantially as herein described with reference to and as illustrated in Fig. 1 6 of the drawings.

31. An electrical plug constructed and arranged substantially as herein described with reference to and as illustrated in Figs. 1 7 and 1 8 of the drawings.

32. An electrical plug constructed and arranged substantially as herein described with reference to and as illustrated in Fig. 1 9 of the drawings.

33. An electrical plug constructed and arranged substantially as herein described with reference to and as illustrated in Figs. 20 and 21 of the drawings.