GB2355865A

GB2355865A - Electrical connecting device

Info

Publication number: GB2355865A
Application number: GB9925580A
Authority: GB
Inventors: Gordon Joseph Clarke
Original assignee: INNOVATIVE POWER SOLUTIONS Ltd
Current assignee: INNOVATIVE POWER SOLUTIONS Ltd
Priority date: 1999-10-28
Filing date: 1999-10-28
Publication date: 2001-05-02
Anticipated expiration: 2019-10-28
Also published as: GB2355865B; GB9925580D0

Abstract

A connecting device (10) for connecting an electrical plug (50) of a first configuration with a socket of differing configuration. The connecting device comprises a casing (11,12) having two or more parts permanently locked together, a plurality of pins (13,14) projecting from the casing for insertion into the socket, and an aperture (23,24) in the casing communicating with a chamber therein for receiving an electrical plug. Connecting means connect each pin (51) of the electrical plug with a respective pin projecting from the casing (13,14). Guide means (28,29,30) in the casing guide the electrical plug into contact with the connecting means and a clamping device (34) retains the electrical plug in the chamber.

Description

2355865 ELECTRICAL CONNECTING DEVICE The present invention relates to a

connecting device (also known as a convertor plug or an adaptor) for allowing an electrical plug to be connected with a socket of differing configuration. In the example described, the converter plug is for allowing a European or US style two-pin electrical plug to be connected to a UK style three-pin receiving socket.

However, the invention is equally applicable to other types of plug, with two or more pins, and other types of socket.

Various types of converter plugs are already known, for example as described in GB 2261774, EP 0342942 and EP 0531383. In these examples, the two pin plug is fitted into the casing of the converter plug before the latter is fully assembled. Therefore, access to the other electrical components within the converter plug is possible and since it is subsequently necessary to assemble and secure the casing of the converter plug, the whole operation is relatively slow and labour intensive.

The present invention provides a connecting device for connecting an electrical plug of a first configuration with a socket of differing configuration, the connecting device comprising a casing having two or more parts permanently locked together, a plurality of pins projecting from the casing for insertion into the socket, an aperture in the casing communicating with a chamber therein for receiving an electrical plug, connecting means for connecting each pin of the electrical plug with a respective pin projecting from the casing, guide means in the casing for guiding the electrical plug into contact with the connecting means and a clamping device for retaining the electrical plug in the chamber. 5 Preferably, the connecting means comprise two or more pairs of resilient arms each receiving a respective pin of the electrical plug therebetween.

The guide means may comprise a plurality of walls defining a side wall and an end wall of the chamber, the end wall having spaced apertures through which the pins of the electrical plug can pass in order to contact the connecting means. 15 In one embodiment, the guide means comprises an insert located in the casing.

Preferably, the clamping device comprises a clamping bar and a tightening means.

The clamping device may be operable to clamp the pins of the electrical plug between the bar and an abutment surface. 2S Alternatively, the clamping device may be operable to clamp the body of the electrical plug between the bar and an abutment surface.

Conveniently, the abutment surface is formed by a part of the guide means.

The tightening means may comprise at least one screw.

The clamping bar may be formed with a recess to f it over each pin.

In one embodiment, the casing parts are permanently locked together by a plurality of cooperating detent means.

Each detent means may comprise a pair of projections having a tapered distal end and a locking shoulder, wherein the tapers allow opposing projections to slide over one another and to snap over the shoulders into locking engagement.

In other embodiments, the casing parts may be is permanently locked together by adhesive, welding or screws.

Similarly, the insert may permanently located in the casing by means of cooperating detents.

The invention will now be described in detail, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is an exploded perspective view of a connecting device in accordance with an embodiment of the present invention; Figure 2 is a cross section along the line A-A of the device of Figure 1 before insertion of the electrical plug; Figure 3 is a cross section along the line A-A of the device of Figure 1 after insertion of the electrical plug; and Figure 4 is a cross section along the line B-B of the device of Figure 3.

A converter device 10 in accordance with the present invention is illustrated in Figure 1. In this example, the device consists of a generally square casing formed from two parts, 11 and 12, although it could consist of a different shaped casing and/or with more than 2 parts. The casing parts 11, 12 are formed from an insulating material, and are typically plastic mouldings.

The f irst casing part 11 consists of a base 11a with an upstanding perimeter wall 11b. Three pins for connection to a UK style mains socket protrude from the base 11a. Two of the pins 13 are the live and neutral pins and are formed from a conductive material. The third pin 14, in this example, is a non-conductive dummy pin 14, because this is the earth pin, the equivalent of which is not usually present in a European or US style 2-pin electrical plug. However, the device 10 could be intended for use with a three pin electrical plug, in which case the third pin 14 would also be conductive.

The first casing part 11 may also hold a fuse 15 which is accessible by removing a snap-fit cover (not shown) from an aperture 16 in the base 11a, in a conventional manner.

The first casing part 11 further contains two pairs of resilient jaws 18, each in communication with a respective conductive pin 13 via conductive connecting means 17.

The second casing part 12 consists of a cover 12a with a downwardly depending perimeter wall 12b. The perimeter walls 11b, 12b of the first and second casing parts 11, 12 are connected togther to form the casing by a number of cooperating detent mechanisms, typically in the form of projections 19, 20. The distal end of 21 of each projection 19,20 is tapered so that as the casing parts 11,12 are pressed together, opposite pairs of projections 19,20 slide over one another and snap into locking engagement on their respective shoulders 22, as seen in Figures 2 and 3. In this example, four pairs of cooperating projections 19, 20 are used to secure the casing parts 11, 12 together. It will be appreciated that a different number and alternative locking mechanisms could be used. For example, the two casing parts 11,12 could be hinged together along one side rather than completely separate and they may be connected together by tamperproof screws, adhesive, ultrasonic or solvent welding etc.

once the casing parts 11, 12 are locked together, it is virtually impossible to disconnect the two parts without seriously damaging or destroying the device 10. Therefore, as described herein, this is considered as a permanent fixing of the two casing parts 11, 12.

The two casing parts 11, 12 each have a trapezoidal opening 23, 24 in part of the perimeter wall 11a,12a such that when the casing parts 11, 12 are locked together, the openings 23, 24 together create a single aperture in the side of the device 10 which is sized and shaped to allow insertion of the 2pin electrical plug 50. Other shapes of aperture are of course possible depending on the profile of the 2pin plug body.

Guide means is provided within the device 10 to define a chamber 40 for receiving the 2-pin electrical plug 50 in the correct orientation to ensure good contact between the pins 51 of the 2-pin plug 50 and the resilient jaws 18 and to prevent unwanted contact between any other parts. Preferably, this guide means consists at least in part of a separate insert 25, made of a non-conductive material such as a plastic moulding.

The insert 25 is located within the first casing part 11. In the embodiment shown this is by means of a circular opening 26 which fits over a cylindrical boss 27 integral with the casing part 11 and projecting upwardly from the base 11a, although other forms of locating the insert 25 can be used. The insert 25 may be permanently locked in position within the casing by means of cooperating detents similar to those described above for joining the two casing parts 11, 12, or any other convenient method.

The insert 25 is formed with walls 28, 29, 30 which define one side of the chamber 40 within the plug 10 which receives the 2-pin plug 50. The other side of the chamber 40 is defined by the interior surface of the second casing part 12, which may be formed with integral ribs or other projections (not shown) to mirror the shape provided by the walls 28, 29, 30 of the insert 25.

The insert 25 is also provides an end wall 31 of the chamber, although this end wall 31 could also be formed by one or more projections from the first or second casing parts 11,12. A pair of spaced apertures 32allow the two pins 51 of the 2-pin electrical plug to pass through the end wall 31 to make contact with the resilient jaws 18.

Beneath each resilient jaw 18, extensions of the insert 25 provide abutments 33 against which the pins 51 of the 2-pin electrical plug 50 may be clamped as described below to retain the plug 50 within the device 10. As seen in Figure 4, the abutments 33 extend down to the base 11a. to provide a firm bracing against which the pins 51 can be clamped.

The retaining means preferably comprises a clamping bar 34 located between the second casing part 12 and the insert 25. The clamping bar 34 comprises a T-shaped plastic moulding. The spine 35 is a hollow cylinder which is received within the cylindrical boss 27 of the first casing part 11. Arms 36 project from opposite sides of the spine 35. Each arm 36 is preferably formed with a shaped recess 37 to fit over a pin of the 2-pin electrical plug. The clamping bar 34 is biased towards the second casing part 12 by means of a spring 38 captured between the spine 35 and the inner surface of the first casing part 11, inside the boss 27. The end face of the spine 35 may be provided with a circular groove to receive the end of the spring 38.

A screw 39 is insertable through a hole in the base 11a of the f irst casing part 11, coaxial with the cylindrical boss 27 and the spine 35. The screw 39 can be tightened in a self -tapping manner into the spine 35 in order to pull the clamping bar 34 down to clamp the pins 51 of the 2-pin plug 50 between the arms 36 and the abutment surfaces 33. In this way, the 2-pin plug 50 is retained within the connecting - 8 device 10 as seen in Figure 3 and 4. The screw 39 may be tamperproof in that it cannot be removed without drilling it out of the connecting device 10, leading to destruction of the device, and thus is considered as a permanent connection. Alternatively, a conventional removable screw may be used.

A number of alternative clamping arrangements are possible. For example, the clamping bar 34 may be arranged to clamp on to the body of the electrical plug instead of its pins. In this case, the clamping bar 34 may be an inverted U-shape, allowing a screw to be tightened into each arm of the U to clamp it on to the plug body. The self tapping clamping screw(s) may be replaced by conventional screw (s) and nut (s), allowing a clamping arrangement which is releasable.

The connecting device 10 can be assembled by positioning the pins 13, 14, the resilient jaws 18 and connecting means in the first casing part 11, positioning the insert 25, the spring 38 and the clamping bar 34 and then snapping the second casing part 12 into place.

In order to use the converter device 10, the 2 pin plug 50 is inserted through the aperture 23,24 into the chamber 40 of the connecting device 10. It is guided by the insert 25 until the pins 51 engage in the resilient jaws 18. The screw 39 can then be tightened into the spine 35 of the clamping bar 34 to permanently retain the plug 50 in the connecting device 10.

In this way, the connecting device 10 can be supplied to manufacturers of electrical goods ready assembled and without allowing access to the interior of the casing. Fitting of the 2-pin plug 50 requires only its insertion into the casing and tightening of the clamping screw 38. Thus, assembly at the stage of manufacturing the electrical appliance is simplified and the device 10 is inherently safer by not allowing contact or access to the electrical components within the casing.

It will be apparent to those skilled in the art that a number of modifications and variations to the precise structure described can be used without departing from the scope of the invention. In particular, while the device is described for is connecting a US or European style 2-pin plug to a UK style socket, the device can be adapted to any type of plug with any socket of differing configuration.

Claims

CLAIMS:

1. A connecting device for connecting an electrical plug of a first configuration with a socket of differing configuration, the connecting device comprising a casing having two or more parts permanently locked together, a plurality of pins projecting from the casing for insertion into the socket, an aperture in the casing communicating with a chamber therein for receiving an electrical plug, connecting means for connecting each pin of the electrical plug with a respective pin projecting from the casing, guide means in the casing for guiding the electrical plug into contact with the connecting means and a clamping device for retaining the electrical plug in the chamber.

2. A connecting device as claimed in claim 1, wherein the connecting means comprise two or more pairs of resilient arms each receiving a respective pin of the electrical plug therebetween.

3. A connecting device as claimed in claim 1 or claim 2, wherein the guide means comprises a plurality of walls defining a side wall and an end wall of the chamber, the end wall having spaced apertures through which the pins of the electrical plug can pass in order to contact the connecting means.

4. A connecting device as claimed in claim 3, wherein the guide means comprises an insert located in the casing.

5. A connecting device as claimed in any of claims 1 to 4, wherein the clamping device comprises a clamping bar and a tightening means.

6. A connecting device as claimed in claim 5, wherein the clamping device is operable to clamp the pins of the electrical plug between the bar and an abutment surface.

7. A connecting device as claimed in claim 5, wherein the clamping device is operable to clamp the body of the electrical plug between the bar and an abutment surface.

8. A connecting device as claimed in claim 6 or claim 7, wherein the abutment surface is formed by a part of the guide means.

9. A connecting device as claimed in any of claims 5 to 8, wherein the tightening means comprises at least one screw.

10. A connecting device as claimed in claim 6, wherein the clamping bar is formed with a recess to fit over each pin.

11. A connecting device as claimed in any preceding claim, wherein the casing parts are permanently locked together by a plurality of cooperating detent means.

12. A connecting device as claimed in claim 11, wherein each detent means comprises a pair of projections having a tapered distal end and a locking shoulder, wherein the tapers allow opposing projections to slide over one another and to snap over the shoulders into locking engagement.

13. A connecting device as claimed in any of claims 1 to 10, wherein the casing parts are permanently locked together by adhesive, welding or screws. 5

14. A connecting device as claimed in claim 4, wherein the insert is permanently located in the casing by means of cooperating detents.

15. A connecting device substantially as hereinbefore described with reference to the accompanying drawings.

44625: SEM: CAP: FURNMCS