GB2153163A

GB2153163A - Fused electrical connector

Info

Publication number: GB2153163A
Application number: GB08401503A
Authority: GB
Inventors: Robert William Taylor; John Yair
Original assignee: Cliff Electronic Components Ltd
Current assignee: Cliff Electronic Components Ltd
Priority date: 1984-01-20
Filing date: 1984-01-20
Publication date: 1985-08-14
Also published as: GB8401503D0; GB2153163B

Abstract

An electrical connector has a housing 1 with a recess 2 in which pins 5 to 7 receive an input from one of two different voltages. A drawer 27 fitting recess 3 carries a fuse 23 through which the electrical input from a live terminal 12, 13 derived from a live pin 5) is to be applied to either of two output terminals 15. Drawer 27 is inserted into recess 3 in an upright or inverted position so that the fuse and drawer is received between the legs 12 and 13 of the live terminal and between the two output terminals 15. In one position of the drawer,0 the fuse is connected with a first of the output terminals 15 and insulated by the drawer from the second output terminal 15. The first output terminal can then be used with a first of the two voltages. In the second position of the drawer the fuse is connected with the second output terminal 15 while the first output terminal is insulated by the drawer so that the second output terminal can be used with the second of the two voltages. <IMAGE>

Description

SPECIFICATION A fused electrical connector unit TECHNICAL FIELD AND BACKGROUND ART This invention relates to a fused electrical connector unit through which an electrical input from a selected one of two different voltages is intended to be applied to an appliance, machine or other electrical device which is intended to be powered by one or the other of the two voltages. Usually the unit will be fitted to the appliance to which the power is to be supplied. Many electrical appliances or machines, especially in industry, can be set for use with either one of two selected voltages, say 1 10 volts or 240 volts, and when the appliance has been set for a predetermined voltage it is important to ensure that the greater voltage is not inadvertently applied to the circuitry. With this in mind a correctly rated fuse should be incorporated in the input to the appliance.Where the appliance is capable of being used with either one of two voltages it is usual for the different voltages to be applied to different circuit parts of the appliance depending upon which voltage is available from an external source. It is an object of the present invention to provide a fused electrical connector unit which lends itself to a relatively small, simple and compact structure, carries connection means through which an electrical input can be applied to the unit (and therethrough to the appropriate circuit part of an appliance machine or other electrical device which is to be powered), includes means for selecting which circuit part of the appliance is to be powered and provides a fuse for whichever circuit part is selected.

STATEMENT OF INVENTION AND ADVAN TAGES According to the present invention there is provided a fused electrical connector unit comprising a housing carrying connection means through which an electrical input from a selected one of two different voltages is intended to be applied to the unit; a carrier of electrically insulating material mounted in the housing, said carrier carrying a fuse through which the electrical input is to be applied from a live terminal of the connection means to either of two output terminals, a first of said output terminals being intended for use with a first of the two voltages and the second output terminal being intended for use with the second voltage, and wherein the carrier can be optionally located in the housing in either of two positions, in a first position the carrier connects the fuse with the first output terminal and insulates the fuse from the second output terminal for use of the unit with the first voltage and in the second position the carrier connects the fuse with the second output terminal and insulates the fuse from the first output terminal for use of the unit with the second voltage.

The connector unit of the present invention may be used with advantage on an electrical appliance or machine which is capable of being powered by either of two predetermined voltages, say 100/120v or 220/240v depending upon which power source is available or convenient. Such an appliance will usually have two different circuit parts for the different voltages and the connector unit will usually be mounted on the appliance with one of its output terminals electrically connected to one circuit part of the appliance for one voltage and the second output terminal electrically connected to the other circuit part of the appliance for the second voltage.If it is intended that the appliance is to operate on,say, 11 0v and such a power source is available, the power source is coupled to the connection means of the unit whilst ensuring that the carrier is located in the housing for the fuse to connect between the live terminal and the appropriate one of the two output terminals which connects with the 11 0v circuit part of the appliance while the other output terminal is insulated from the fuse by the carrier. In the event that a 220v power source is available then it is a simple matter to locate the carrier in its second position so that the fuse connects between the live terminal of the unit and the second output terminal which connects with the 220v circuit part of the appliance while the first output terminal is now insulated from the fuse by the carrier.

The connection means of the unit will usually comprise a socket within which are mounted pins which are intended to engage in a plug from the available electrical supply (when the plug is pushed into the socket). For general purposes an alternating current mains supply with live, neutral and earth terminals will be provided and corresponding terminals will be available in the connection means. The live terminal with which the fuse engages may be in constant electrical communication with the corresponding live terminal of the connection means while the neutral and earth terminals of the connection means will be available for connection to the circuitry of the electrical appliance as appropriate.

The optional location of the carrier in either of its two positions can be achieved by rotational adjustment of the carrier within the housing but is preferably achieved by having the carrier removable so that it can be withdrawn from the housing, rotated (say through substantially 180 ) and re-inserted into the housing to selectively change the fusing from one output terminal to the other. Where the carrier is intended to be removed from the housing it is preferably in the form of a drawer in which the fuse is cradled (preferably as a press or snap fit) so that exposed termi nal end parts of the fuse are exposed for connecting with the live terminal and with the appropriate and selected one of the two output terminals (depending upon the orientation of the drawer when it is reinserted into the housing).

The rating of the fuse will naturally be selected in accordance with the electrical characteristics of the appliance with which the unit is to be used. Preferably the fuse is of conventional structure comprising a cylindrical tube of electrically insulating material through which a fuse wire extends and connects with substantially cylindrical end caps of electrically conducting material mounted on the tube.

DRAWINGS One embodiment of a fused electrical connector unit constructed in accordance with the present invention will now be described, by way of example only, with reference to the accompanying illustrative drawings in which: Figure 1 shows a front elevation of the unit in which the carrier has been partly cut away to illustrate the fuse; Figure 2 is a section of the unit taken on the line A-A of Figure 1; Figure 3 is a part section of the unit taken on the line B-B of Figure 1; Figure 4 is a plan view of an output terminal incorporated in the unit as shown in Figure 3, and Figure 5 is a perspective view of the unit showing the carrier and fuse carried thereby withdrawn from the housing.

DETAILED DESCRIPTION OF DRAWINGS The connector unit comprises a one piece housing 1 moulded in plastics or other insulating material and having, in its front, adjacent sockets 2 and 3 and external flanges 4. The flanges 4 provide a convenient means for attaching the unit by screws or otherwise to an electrical appliance or machine which is to be powered by an electrical supply through the unit. For the purpose of the present example it will be assumed that the appliance (not shown) is capable of being operated with an alternating current supply at either 11 0v or 220v and includes appropriate circuitry for such alternative use when connected to a conventional mains supply comprising live, neutral and earth terminals.

Having the aforegoing in mind, the socket 2 accommodates three terminal pins consisting of a live pin 5, an earth pin 6 and a neutral pin 7 which are intended to be received in and mate with complementary and corresponding terminals in a plug (not shown) which is press fitted into the socket 2. The plug will connect with the mains supply at the appropriate 110/220 voltage at which it is intended the appliance should operate. The connector pins 6 and 7 will have terminals (not shown) extending from a rear wall 8 of the housing 1 by which they can be coupled to the appropriate earth and neutral connections respectively on the appliance.

The live pin 5 extends through the rear wall 8 of the housing and is rivetted to an electrically conductive plate 9 which bridges between the rear of the sockets 2 and 3. Located within the socket 3 is a substantially Ushaped live terminal 10 which is secured through its base and through the wall 8 to the plate 9 by a rivet 11 of electrically conductive material. The terminal 10 is of electrically conductive spring material so that its opposed legs 1 2 and 1 3 are resiliently biased towards each other. Also located within the socket 3 are two opposed output terminals 1 4 and 1 5 which are spaced from and substantially in alignment with the legs 1 2 and 1 3 respectively of the live terminal 10 as shown in Figure 1.The output terminals 1 4 and 1 5 are mounted in slots 1 6 and 1 7 respectively in the rear wall 8 of the housing to be insulated from each other and each comprises a pressed metal strip (as best seen from Figures 3 and 4). The metal strip for each output terminal may be of a spring material and is pressed to form a barb 1 9, "L" shaped flanges 20 and terminal connections 21.Each of the output terminals 14, 1 5 is simply fitted to the housing by pressing the terminal from the recess 3 and through the appropriate slot 1 6 or 1 7 so that the flange 20 abuts against the inner side of the rear wall 8 and the barb 1 9 springs out to engage against the outer side of the rear wall 8 to retain the terminal. The terminals 14 and 1 5 are stabilised in the rear wall 8 by the "L" shape of the flanges 20 abutting the opposed sides of the socket 3 and by the terminals lying over flanges 22 moulded in the rear wall.For the purpose of the present example, the connection points 21 of the output terminal 1 4 will be coupled to the 220v circuit part of the appliance to which the unit is fitted while the connection points 21 of the output terminal 15 will be coupled to the 11 Ov circuit part of the appliance.

The live terminal 10 is electrically connected to one or other of the output terminals 14 and 1 5 by a fuse 23 which is of conventional form comprising a cylindrical tube 24 of insulating material through which extends a fuse wire (not shown) to interconnect metallic cylindrical end caps 25 and 26 within which the ends of the tube 24 are respectively received. The fuse 23 is cradled in a drawer 27 of electrically insulating material (conveniently moulded in plastics). The drawer 27 is a press fit into and removable from the socket 3 and has a part cylindrical recess 28 which is substantially complementary to the cylindrical profile of the fuse 23 and within which the fuse is accommodated as a snap or press fit.

As will be seen from Figures 2, 3 and 5 minor parts of the cylindrical profiles of the end caps 25 and 26 project from the recess 28 and it is these parts of the end caps which are intended to connect with the live terminal 10 and with one or other of the output terminals 14 and 15. The drawer 27 can be inserted into the socket 3 in either of two positions, one position corresponding to the drawer being rotated through 180 from the other position so that the drawer can be inserted into the socket 3 in one position as shown in Figure 5 where the mouth of the recess 28 is directed upwardly or in the alternative second position where the mouth of the recess 28 is directed downwardly.In either of these two positions, as the drawer 27 is pressed into the recess 3, the fuse 23 and its accommodating part cylindrical wall 29 of the drawer 27 will be pressed and located simultaneously between the opposed legs 1 2 and 1 3 of the live terminal 10 and between the opposed terminals 14 and 1 5 (as shown in Figures 2 and 3). It will be seen from Figures 2 and 3 that the ends of the terminals 10 and 14 and 1 5 are splayed to facilitate reception of the fuse and drawer and are also bowed to accommodate the surface of the fuse and wall 29 with which they are in contact. The live terminal 10 is spaced from the output terminals 1 4 and 1 5 to correspond with the distance between the fuse end caps 25 and 26.Consequently when the drawer 27 is inserted into the socket 3 in the position shown in Figure 5 the end cap 25 contacts the live terminal 10 through the leg 1 2 thereof (whilst the leg 1 3 is insulated from the end cap 25 by the wall 29 of the drawer) and the end cap 26 contacts the output terminal 14 while the output terminal 1 5 is insulated from the end cap 26 by the wall 29 of the drawer; with this positioning it is intended that a 220v supply is applied to the connector unit through the pins 5 to 7 and that the appliance will operate from this supply through the output terminal 1 4. Alternatively, if an ll0v supply is available to the pins 5 to 7, the drawer 27 is withdrawn from the socket 3, rotated through 180 to its second position and reinserted into the socket 3 so that the fuse and drawer will again be pushed simultaneously between the opposed legs 1 2 and 1 3 of the live terminal 10 and between the opposed output terminals 14 and 1 5. In this second position however, where the drawer 27 is inverted from the position shown in Figures 2 and 3, the end cap 26 will connect with the live terminal through the leg 1 3 thereof (while the leg 1 2 is insulated from the end cap 26 by the wall 29) and the end cap 25 will connect with the output terminal 1 5 (while the output terminal 14 is insulated from the end cap 25 by the wall 29); the 11 0v supply to the connector unit is now available through the fuse 23 and the output terminal 1 5 to the 11 0v circuit part of the appliance.

Preferably the opposed output terminals 1 4 and 15, like the legs 1 2 and 13, are sprung to be resiliently biased towards each other to ensure close contact between the terminals and the fuse.

It will be apparent that the rating of the fuse is appropriate for the characteristics of the appliance to which the unit is fitted. The face of the drawer 27 may carry markings 30 to indicate which of the output terminals 1 4 and 1 5 is operative by the positioning of the drawer and conveniently the drawer has a chamber 31 or other accommodation within which a spare fuse can be retained.

The recess 3 is conveniently located adjacent to the recess 2 so that, when a plug is located in the recess 2, the plug overlies the drawer 27 to prevent its withdrawal.

Claims

1. A fused electrical connector unit comprising a housing carrying connection means through which an electrical input from a selected one of two different voltages is intended to be applied to the unit; a carrier of electrically insulating material mounted in the housing, said carrier carrying a fuse through which the electrical input is to be applied from a live terminal of the connection means to either of two output terminals, a first of said output terminals being intended for use with a first of the two voltages and the second output terminal being intended for use with the second voltage, and wherein the carrier can be optionally located in the housing in either of two positions, in a first position the carrier connects the fuse with the first output terminal and insulates the fuse from the second output terminal for use of the unit with the first voltage and in the second position the carrier connects the fuse with the second output terminal and insulates the fuse from the first output terminal for use of the unit with the second voltage.

2. A unit as claimed in claim 1 in which the carrier is rotatable to be optionally located in either of its two positions.

3. A unit as claimed in either claim 1 or claim 2 in which the carrier is removable from the housing to effect its adjustment from one position to the other prior to the carrier being reinserted into the housing.

4. A unit as claimed in any one of the preceding claims in which the carrier is in the form of a drawer by which the fuse is withdrawn from and reinserted into the housing for dis-engagement and engagement respectively with the live terminal and the selected one of the two output terminals substantially simultaneously.

5. A unit as claimed in claim 4 in which the drawer when withdrawn from the housing is rotated through substantially 180 and reinserted into the housing to selectively change the fusing from one output terminal to the other output terminal.

6. A unit as claimed in any one of the preceding claims in which the fuse is generally cylindrical comprising a tube of electrically insulating material through which a fuse wire extends and which wire connects with substantially cylindrical end caps of electrically conductive material mounted on the tube and wherein the carrier extends part way around the periphery of the end caps to provide exposed peripheral regions of said caps which exposed peripheral regions are intended for connection with the live terminal and with the selected one of the two output terminals.

7. A unit as claimed in claim 6 in which the fuse is received as a snap or press fit in a part cylindrical recess of the carrier.

8. A unit as claimed in any one of the preceding claims in which the live terminal comprises two opposed terminal parts between which the carrier and fuse are received in the first position with the fuse connecting with one terminal part and being insulated by the carrier from the second terminal part and in the second position with the fuse connecting with the second terminal part and being insulated by the carrier from the one terminal part.

9. A unit as claimed in claim 8 in which the live terminal is of substantially U-shape the legs of which comprise the two opposed terminal parts.

10. A unit as claimed in either claim 8 or claim 9 in which the two opposed terminal parts of the live terminal are sprung to resiliently receive the carrier and fuse between them.

11. A unit as claimed in any one of the preceding claims in which the first and second output terminals oppose each other and are sprung to resiliently receive the cradle and fuse between them.

1 2. A unit as claimed in any one of the preceding claims in which each of the first and second output terminals are mounted in a wall of the housing and are retained on said wall by spring barbs which react against the housing.

1 3. A unit as claimed in claim 1 2 in which each of the output terminals comprises a pressed metal strip mounted in a slot in the wall of the housing to extend through that wall.

14. A unit as claimed in any one of the preceding claims in which the connection means and carrier are respectively mounted in two adjacent recesses in the housing with the live terminal electrically connected to a live input of the connection means.

1 5. A unit as claimed in claim 14 in which the connection means comprise pins accom modated within the recess for that means, said recess being intended to receive a plug from which an electrical supply is to be de rived for the pins.

1 6. A unit as claimed in claim 1 5 in which the live terminal connects with a live pin of the connection means through an electrically conductive plate mounted on the housing.

1 7. A unit as claimed in claim 1 6 when appendant to claim 9 in which the live pin and substantially U-shaped live terminal are secured by rivetting to the housing and said electrically conductive plate is retained on said housing and connected to the live pin and live terminal by said rivetting.

1 8. A unit as claimed in any one of the preceding claims in which the carrier is withdrawable from the housing and includes means for accommodating a spare fuse.

1 9. A fused electrical connector unit substantially as herein described with reference to the accompanying illustrative drawings.