ELECTRICAL ADAPTOR

Abstract: An electrical adaptor is arranged to receive an electrical plug of one standard type and to be inserted into sockets of other standard types. Selection of different pin configurations to allow insertion into the various sockets is by way of a rotatable end portion having apertures therein. The end portion is large in comparison to the adaptor as a whole and may be easily manipulated for the selection of the various pin configurations. The adaptor preferably includes a fuse link in the live connection, and the fuse may be accessed through the end portion when it is in a particular rotational position.

Description: Electrical Adaptor The present invention relates to electrical adaptors which allow an electrical appliance connected to a conventional plug according to one standard to be connected to an electrical supply outlet of a type according to a different standar . It is known to provide such adaptors with a choice of pin configurations which may be selected for plugging into various electrical supply sockets. The selection means provided on such adaptors is typically quite small and requires considerable manual dexterity to use due to the smallness of the parts required to be moved. The present invention provides an electrical adaptor comprising a main body having first and second ends, a plurality of socket contacts arranged to receive an electrical plug inserted through apertures in the first end of the main body, a plurality of pins adapted to be selectively extended from said second end in a plurality of configurations, each of said pin configurations being suitable for insertion into and connection with a standard electrical socket, and means within the adaptor arranged to make appropriate live and neutral connections between a plug inserted into said socket contacts and the pins when in position for insertion into an electrical socket; the adaptor further comprising an end portion having a cross sectional area substantially the same as or larger than the second end of the main body and a plurality of apertures therein and rotatably mounted on the second end of said main body whereby the end portion may be rotated to a plurality of rotational positions with respect to the main body, each of said rotational positions corresponding to one of said pin configurations, the apertures in said end portion being arranged such that the pins for each pin configuration may be extended from the second end when the end portion in is the respective corresponding rotational position. The present invention therefore provides an adaptor having a selection means for the various pin configurations which is relatively large and which is simple to use. The present invention preferably includes a fuse link in the live connection within the main body, the fuse link being accessible through a further aperture in the end portion. In order that the present invention may be better understood preferred embodiments thereof will be described by way of example, with reference to the accompanying drawings, in which: Figures la and lb show two perspective views of a first preferred embodiment; Figure 2 is a cross-sectional view of the adaptor shown in figures la and lb; Figure 3 shows the front of the adaptor with the selection means- removed; Figure 4 illustrates one of the pins incorporated in the preferred embodiment. Figure 5 illustrates a fuse link incorporated into the adaptor according to a second preferred embodiment; and Figure 6 illustrates the front of the adaptor modified according to the embodiment of figure 5. The electrical adaptor according to the preferred embodiments of this invention allows an electrical appliance having a European standard 2-pin plug, either with or without external earth contacts, to be connected but without earth connection to electrical supply sockets of other standard types, referred to herein as US style sockets, UK style sockets and European recessed sockets. The adaptor of the preferred embodiments has an end portion which rotates to allow the selection of the various pin configurations necessary to plug into supply sockets of the types mentioned above. Figures la and lb show two views of the first preferred embodiment in its closed position. The adaptor 1 may be described as being a tapered shape with two ends, the larger being referred to as the front and the smaller as the rear. At the front of adaptor 1 is a front portion 2 having a number of holes therein. At the rear of adaptor 1 is a recessed socket 3 which may be adapted to receive European standard 2-pin plugs and/or a US 2-pin plug and/or an Australian (southern hemisphere) 2-pin plug. The following description- is in terms of a European plug and it is understood that small changes may be required to the socket design for use with US or southern hemisphere style plugs. In use, a standard European plug is inserted into recessed socket 3 and selected pins are extended from within adaptor 1 through holes in the front portion 2, as will be described in details below, in either the US standard configuration, the Australian (southern hemisphere) standard configuration, the UK standard configuration or that of a standard European recessed socket. The recessed socket 3 is not described in detail herein as it is quite standard in the art of adaptors such as this. It will be evident from figure la that the generally circular hole in the rear of adaptor 1 in the preferred embodiment is shaped to receive an earthed European plug although the adaptor makes no electrical earth connection. Mouldings 4 are in positions corresponding to the positions of wiping earth contacts in a recessed European socket, and mouldings 5 receive the lugs found on corresponding earthed European plugs. Within socket 3 is wall 6 in which are two holes, not shown in figure 1 adapted to receive the pins of a European plug. Behind each of said holes is a metal is a metal clip adapted to make electric contact with a respective one of the pins of a European plug inserted into socket 3. Figure 2 is a cross-sectional view of adaptor 1 showing socket 3 and front portion 2. Figure 2 also shows clip 7 behind wall 6 which receives a pin of a European plug as described above. As can be seen in figure 2 front portion 2 is a snap fit onto the front of adaptor 1 and is held in position by way of protuberances 8 on front portion 2 and a corresponding recess in the main body of the adaptor. The front end of the adaptor is circular and the recess runs the full length of the perimeter, thereby allowing front portion 2 to rotate about the major central axis of the adaptor. Within adaptor 1 behind front portion 2 are positioned contact plates 9, one of which is shown in figure 2. Each contact plate 9 is electrically connected via a contact pin 10 to a respective clip 7 as shown. Contact plates 9 enable the selected pins of the adaptor to be electrically connected to clips 7 and hence to the pins of a plug inserted in socket 3 of the adaptor, as will be described below. Figure 3 illustrates the front of adaptor 1 with front portion 2 removed. The circular end of the main body of adaptor 1 is shown, as are the two contact plates 9. As mentioned above each of contact plates 9 is electrically connected to one of clips 7. Each contact plate 9 has therein holes 11, 12 and 13. Holes 11, 12 and 13 have behind them cavities within adaptor 1 within which are pins adapted to conform to various standards which may selectively be withdrawn through holes 11, 12 or 13 to provide plug configurations for connection to sockets of US, UK or European style sockets. Holes 11 in contact plate 9 are of a size to allow flat cross-section pins of appropriate dimensions to fit a standard US style socket to pass through. Such pins are provided in adaptor 1 and when not in use are positioned in cavities behind holes 11 within adaptor 1. When required the pins are caused to slide through holes 11. Figure 4 illustrates such a US style pin. The pin comprises the flat cross-section portion 30 which has a narrower end portion 31. Over end portion 31 is positioned movable plate 32 and spring 33 which are retained by fixed plate 34. In order to fix the pin in position, main portion 30 is caused to slide through one of holes 11 and movable plate 32 rests against the inside of the contact plate. The pin is then pulled further through the hole, compressing spring 33, and is turned. The biasing of the spring then fixes the pin in position and ensures electrical connection between the pin and the contact plate. The pins in holes 11 may either be positioned parallel to each other for use with US sockets, or may be angled with respect to each other for use in some southern hemisphere countries. Holes 12 in contact plates 9 are of a size to allow rectangular cross-section pins of appropriate dimensions to fit live and neutral connections of a standard UK style socket to pass through. Such pins are provided in cavities behind holes 11 and when required the pins are caused to slide though holes 11. These UK pins have a spring fixing similar to that described above with respect to the US pins and when required are withdrawn through holes and 11 turned to be in the correct orientation to fit in a UK style-socket. Holes 13 in contact plates 9 are provided to allow pins of appropriate dimensions to fit a standard European style socket to be selected. Each hole 13 is basically circular, and has slotted portions 14, 15 and 16. Slots 16 extend to the edges of contact plates 9 and a channel is formed thereby which joins the two holes 13. A plastic housing is provided behind holes 13 within the adaptor which has the same cross-section as the combination of holes 13 and slots 14, 15, 16. The plastic housing also has two bores passing though it concentric with the two holes 13 through which the pins to fit a European socket extend. When the European standard pins are in position the plastic housing is withdrawn out of holes 13 such that its length in front of the front plate 2 when fitted is the same as the depth of a European recessed socket. The pins which are provided are long enough such that they extend through the plastic housing far enough to fit a European socket and have a threaded end portion which screws into the thread around hole 13. This fixes the pins and housing in position and provides electrical connection between each pin and its respective contact plate 9. The ribs along the housing corresponding to slots 14 enable the housing to be plugged into a European recessed socket and they co¬ operate with parts corresponding to mouldings 5 described above in socket 3. The moulding is described in this embodiment as being plastic but clearly any insulating material may be used to manufacture the housing. When the European pins are not required the pins and the housing are returned to the cavity or cavities behind holes 13 within adaptor 1. The selection of the various pin configurations will be described with reference to a comparison between the front portion 2 shown in figure lb and figure 3. With the front portion 2 in the position shown in figure lb it will be appreciated that the UK standard pins may be caused to slide through holes 12 in contact plates 9 and through hole 17 and fixed in positions as described above, thereby to extend from the front of the adaptor. The UK standard configuration is completed by a dummy 'earth' pin extending from hole 18. This adaptor provides no earthing connection but in order to be plugged into a standard UK socket an earth pin must be present in order to move the shutter in the socket to allow access for the live and neutral pins. The dummy pin may therefore be manufactured of any material but in the preferred embodiment it is plastic. As can be seen in figure lb hole 18 is a circular recess with a rectangular slot. The dummy earth pin is provided in a cavity behind hole 18. It is caused to slide through the slot in hole 18 and turned to be fixed in position seated in the circular recess. The fixing may be similar to the fixing described above for the UK and US live and neutral pins, or may be any other convenient arrangement. For the dummy earth pin, no electrical connection is necessary. Hole 18 is not central in front portion 2 and therefore when front portion 2 is turned from the position in figure lb, the earth pin cannot be withdrawn. To select the European pin configuration, front portion 2, is turned through 180° from the position shown in figure lb. In this position hole 17 is aligned with holes 13 and slots 14, 15, 16 and the European pins and housing may be withdrawn through hole 17. To select the US in configuration, front portion 2 is turned to align holes 19 with slots 11 in contact plates 9. In this position the US pins may be withdrawn through holes 19 and fixed in position as described above. Therefore the selection of the desired pin configuration is effected by rotation of front portion 2. When front portion 2 is in a position to select a particular pin configuration, the pins of other configurations are retained within adaptor 1 by front portion 2. Front portion 2 may also be rotated to a closed position in which all of the pins are retained within adaptor 1, for instance if front portion 2 is rotated 90° from the position shown in figure lb. To assist in the selection of the various pin configuration, marks may be applied to the main body of adaptor 1 and the periphery of front portion 2 to indicate the correct rotational positions for the various pin configurations. As shown in figures la and lb front portion 2 has cut-away portions 20. The resulting shape is easy to grip in order to turn front portion 2. Front portion 2 is also provided with arcuate slots 21. These slots enable protuberances 8 (shown in figure 2) to be moulded and allow front portion 2 to be snapped onto the adaptor 1 during assembly. The marks to assist in the selection of the various configurations may be on the flat surfaces cut¬ away portions 20, or alternatively may be visible through holes in these surfaces, those holes being either slots 21 or further apertures not shown in the drawings. Figures 5 and 6 illustrate a second preferred embodiment of this adaptor which is a modification of the first in which a fuse link is incorporated into the design in order to provide increased safety. Figure 5 is a cross sectional view of the fuse link in this embodiment. As is apparent from a comparison of this figure with figure 2, in this embodiment one of the contact pins 10 is replaced with a fuse link to provide the electrical connection between the respective socket 7 and contact plate 9. The contact pin to be replaced is preferably that in the live side of the adaptor, that being the usual position for a fuse in a plug or adaptor. In the preferred arrangement described below a standard replaceable cartridge fuse is included in the adaptor. However the design may be modified to include any known fuse arrangement. The fuse link illustrated in figure 5 comprises fuse base holder 51, sleeve 52 and fuse top holder 53 which has fuse screw cap 54 attached to it. Fuse base holder 51 is made from an electrically conductive material and is riveted to socket contact 7 in order to make electrical contact thereto. Fuse top holder is also made from an electrically conductive material and screws into an additional hole provided in contact plate 9 as shown in order to make electrical contact thereto. Fuse screw cap 54 is manufactured from an electrically insulating material. Sleeve 52 is also manufactured from an electrically insulating material and acts to provide mechanical spacing between the fuse top and base holders 53 and 51. As shown a cartridge fuse 55 is positioned between the fuse base holder 51 and the fuse top holder 53, there being an electrically conductive spring 56, preferably conical, between the fuse and the fuse base holder and this ensures good electrical contact at each end of the fuse. Thus the electrical connection between the socket contact 7 and the contact plate 9 is only via the fuse 55. The fuse screw cap 54 as illustrated is provided with a groove to enable it, together with the fuse top holder, to be unscrewed for instance using a screwdriver. To replace the fuse 55 the fuse screw cap 54 together with the fuse top holder 53 is unscrewed from the contact plate 9. An old fuse can then be removed and a new one inserted into sleeve 52 before replacing the fuse top holder 53 and fuse screw cap 54. Figure 6 shows front portion 2 ' which is used in this preferred embodiment. Front portion 2 ' is a modified version of front portion 2 described above and has therein holes 17, 18 and 19 for the selection of the various pin configurations. There is also provided an • additional hole 60 in front portion 2' such that the front portion can be rotated to a position in which fuse screw cap 54 may be accessed through hole 60. This position is preferably a different position to the positions described above for the selection of the various pin configurations.

Claims: CLAIMS : 1. An electrical adaptor comprising a main body having first and second ends, a plurality of socket contacts arranged to receive an electrical plug inserted through apertures in the first end of the main body, a plurality of pins adapted to be selectively extended from said second end in a plurality of configurations, each of said pin configurations being suitable for .insertion into and connection with a standard electrical socket, and means within the adaptor arranged to make appropriate live and neutral connections between a plug inserted into said socket contacts and the pins when in position for insertion into an electrical socket; the adaptor further comprising an end portion having a cross sectional area substantially the same as or larger than the second end of the main body and a plurality of apertures therein and rotatably mounted on the second end of said main body whereby the end portion may be rotated to a- plurality of rotational positions with respect to the main body, each of said rotational positions corresponding to one of said pin configurations, the apertures in said end portion being arranged such that the pins for each pin configuration may be extended from the second end when the end portion in is the respective corresponding rotational position. 2. An electrical adaptor according to claim 1 having a tapered shape, the second end being larger than the first end. 3. An electrical adaptor according to claim 1 or 2 in which the end portion mounted on the second end is shaped so as to be easily gripped for rotation by hand between said rotational positions. 4. An electrical adaptor according to any of claims 1 to 3 in which one of said pin configurations is adapted to co-operate with a standard European style socket. 5. An electrical adaptor according to any of claims 1 to 3 in which one of said pin configurations is adapted to co-operate with a standard North American style socket. 6. An electrical adaptor according to any of claims 1 to 3 in which one of. said pin configurations is adapted to co-operate with a standard UK style socket. 7. An electrical adaptor according to any of claims 1 to 6 arranged to receive a European style plug. 8. An electrical adaptor according to any of claims 1 to 7 further comprising means to receive a fuse in series with one of the live and neutral connections in the adaptor. 9. An electrical adaptor according to claim 8 in which said fuse may be inserted through said second end. 10. An electrical adaptor according to claim 9 in which said end portion has therein a further aperture positioned to allow access to said ' fuse when the end portion is in a predetermined rotational position.

Inventors: WRIGHT PHILIP, WRIGHT, PHILIP
Applicants: ROSS GROUP PLC
Application year: 1992
Main classification: H01R31
IPC codes: H01R27, H01R31