GB2081529A

GB2081529A - Electric plug assembly

Info

Publication number: GB2081529A
Application number: GB8123209A
Authority: GB
Original assignee: BICC PLC
Current assignee: Balfour Beatty PLC
Priority date: 1980-07-30
Filing date: 1981-07-28
Publication date: 1982-02-17

Abstract

In an electric plug assembly comprising an insulating plug body from which the plug pins project and a length of flexible insulated multi-conductor cable whose electric conductors are permanently electrically connected to the associated plug pins, a metal tab 3, directly or indirectly electrically connected to one of the cable conductors within the plug body, has a hole 4 extending through the tab and one of the plug pins 1 has, projecting axially from the pin, an integral spigot 2 which protrudes through the hole in the tab and is so distorted by the formation of a depression 5 that the tab is permanently clamped to the pin. <IMAGE>

Description

SPECIFICATION An improved electric plug assembly This invention relates to electric plug assemblies and is especially, but not exclusively, concerned with electric plug assemblies for use in domestic and similar wiring systems.

According to the invention, we provide an improved electric plug assembly comprising an insulating plug body from which at least two plug pins project and a length of flexible insulated multi-conductor cable whose electric conductors are permanently electrically connected to the associated plug pins, wherein a tab of metal or metal alloy, directly or indirectly electrically connected to one of the cable conductors within the insulating plug body, has a hole extending through the tab and wherein one of the plug pins has, projecting from the pin at or adjacent that one of its ends within the insulating plug body, an integral spigot which protrudes through the hole in the tab and is so distorted that the tab is permanently clamped to the pin.

Preferably, the integral spigot projects lengthwise from the end of the pin within the insulating plug body and is distorted in a direction substantially parallel to the pin axis to clamp the tab permanently to the end face of the pin. Distortion of the spigot is preferably effected by controlled impact punching, in a direction substantially along the spigot axis, a depression of such a depth as to cause the material of the spigot to flow outwardly from the spigot axis and to overlie and clamp the tab to the end face of the pin.

Each pin of the electric plug assembly may have, projecting from the pin at or adjacent that one of its ends within the insulating plug body, an integral spigot which protrudes through a hole in one of a number of tabs of metal or metal alloy, each directly or indirectly electrically connected to one of the cable conductors, and which is so distorted that the tab is permanently clamped to the pin.

Where the or a metal tab is indirectly electrically connected to one of the cable conductors, it may be spot welded or otherwise permanently electrically connected to one of two resilient clips for reception of a cartridge fuse. Where the or a metal tab is directly electrically connected to one of the cable conductors, it may be formed with an integral ferrule in which the bare end of the cable conductor is crimped.

The arrangement hereinbefore described of permanently connecting a plug pin to one of the conductors of a flexible cable is applicable to both to an electric plug assembly of the kind in which the plug pins protrude through holes in a preformed body of electrically insulating material, the conductors of a length of flexible insulated multi-conductor cable are permanently electrically connected to associated plug pins, and a moulded plug body of electrically insulating material wholly or partially encapsulates the preformed body and the plug pins and associated conductor connections with an appropriate length of each pin protruding from the plug assembly and is permanently bonded to the insulating covering of an adjacent part of the length of cable, and to an electric plug assembly of the kind in which the plug pins protrude through holes in one of two preformed shells of electrically insulating material, which shells are welded or otherwise permanently secured together to form an insulating plug body housing the permanent electrical connections between the plug pins and the electric conductors of a length of flexible insulated multi-conductor cable.

The invention will be further illustrated by a description, by way of example, of the preferred method of permanently electrically connecting the live pin of a 1 3A three-pin plug assembly to a resilient fuse clip with reference to the accompanying drawing which shows a fragmental isometric view of the live pin and a metal tab, partly in section.

Referring to the drawing, the live pin 1 has, projecting axially from one end of the pin, a spigot 2. The metal tab 3 through which a hole 4 extends is applied over the spigot 2 so that it protrudes through the hole and the spigot is distorted by controlled impact punching, in a direction substantially along the spigot axis, to form a depression 5 of such a depth as to cause the material of the spigot to flow outwardly from the spigot axis and overlie and clamp the tab 3 permanently to the end face of the pin 1. The other end (not shown) of the tab 3 is spot welded to one of the resilient fuse clips of the plug.

1. An electric plug assembly comprising an insulating plug body from which at least two plug pins project and a length of flexible insulated multi-conductor cable whose electric conductors are permanently electrically connected to the associated plug pins, wherein a tab of metal or metal alloy, directly or indirectly electrically connected to one of the cable conductors within the insulating plug body, has a hole extending through the tab and wherein one of the plug pins has, projecting from the pin at or adjacent at that one of its ends within the insulating plug body, an integral spigot which protrudes through the hole in the tab and is so distorted that the tab is permanently clamped to the pin.

2. An electric plug assembly comprising an insulating plug body from which at two plug pins project and a length of flexible insulated multi-conductor cable whose electric conductors are permanently electrically connected to the associated plug pins, wherein a tab of metal of metal alloy, directly or indi

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION An improved electric plug assembly This invention relates to electric plug assemblies and is especially, but not exclusively, concerned with electric plug assemblies for use in domestic and similar wiring systems. According to the invention, we provide an improved electric plug assembly comprising an insulating plug body from which at least two plug pins project and a length of flexible insulated multi-conductor cable whose electric conductors are permanently electrically connected to the associated plug pins, wherein a tab of metal or metal alloy, directly or indirectly electrically connected to one of the cable conductors within the insulating plug body, has a hole extending through the tab and wherein one of the plug pins has, projecting from the pin at or adjacent that one of its ends within the insulating plug body, an integral spigot which protrudes through the hole in the tab and is so distorted that the tab is permanently clamped to the pin. Preferably, the integral spigot projects lengthwise from the end of the pin within the insulating plug body and is distorted in a direction substantially parallel to the pin axis to clamp the tab permanently to the end face of the pin. Distortion of the spigot is preferably effected by controlled impact punching, in a direction substantially along the spigot axis, a depression of such a depth as to cause the material of the spigot to flow outwardly from the spigot axis and to overlie and clamp the tab to the end face of the pin. Each pin of the electric plug assembly may have, projecting from the pin at or adjacent that one of its ends within the insulating plug body, an integral spigot which protrudes through a hole in one of a number of tabs of metal or metal alloy, each directly or indirectly electrically connected to one of the cable conductors, and which is so distorted that the tab is permanently clamped to the pin. Where the or a metal tab is indirectly electrically connected to one of the cable conductors, it may be spot welded or otherwise permanently electrically connected to one of two resilient clips for reception of a cartridge fuse. Where the or a metal tab is directly electrically connected to one of the cable conductors, it may be formed with an integral ferrule in which the bare end of the cable conductor is crimped. The arrangement hereinbefore described of permanently connecting a plug pin to one of the conductors of a flexible cable is applicable to both to an electric plug assembly of the kind in which the plug pins protrude through holes in a preformed body of electrically insulating material, the conductors of a length of flexible insulated multi-conductor cable are permanently electrically connected to associated plug pins, and a moulded plug body of electrically insulating material wholly or partially encapsulates the preformed body and the plug pins and associated conductor connections with an appropriate length of each pin protruding from the plug assembly and is permanently bonded to the insulating covering of an adjacent part of the length of cable, and to an electric plug assembly of the kind in which the plug pins protrude through holes in one of two preformed shells of electrically insulating material, which shells are welded or otherwise permanently secured together to form an insulating plug body housing the permanent electrical connections between the plug pins and the electric conductors of a length of flexible insulated multi-conductor cable. The invention will be further illustrated by a description, by way of example, of the preferred method of permanently electrically connecting the live pin of a 1 3A three-pin plug assembly to a resilient fuse clip with reference to the accompanying drawing which shows a fragmental isometric view of the live pin and a metal tab, partly in section. Referring to the drawing, the live pin 1 has, projecting axially from one end of the pin, a spigot 2. The metal tab 3 through which a hole 4 extends is applied over the spigot 2 so that it protrudes through the hole and the spigot is distorted by controlled impact punching, in a direction substantially along the spigot axis, to form a depression 5 of such a depth as to cause the material of the spigot to flow outwardly from the spigot axis and overlie and clamp the tab 3 permanently to the end face of the pin 1. The other end (not shown) of the tab 3 is spot welded to one of the resilient fuse clips of the plug. CLAIMS

2. An electric plug assembly comprising an insulating plug body from which at two plug pins project and a length of flexible insulated multi-conductor cable whose electric conductors are permanently electrically connected to the associated plug pins, wherein a tab of metal of metal alloy, directly or indi rectly electrically connected to one of the cable conductors within the insulating plug body, has a hole extending through the tab and wherein one of the plug pins has, projecting lengthwise from the pin at that one of its ends within the insulating plug body, an integral spigot which protrudes through the hole in the tab and is so distorted in a direction substantially parallel to the pin axis that the tab is permanently clamped to the end face of the pin.

3. An electric plug assembly as claimed in Claim 2, wherein the integral spigot of the pin is distorted in a direction substantially along the spigot axis to form a depression of such a depth that the material of the spigot flows outwardly from the spigot axis and overlies and clamps the tab to the end face of the pin.

4. An electric plug assembly as claimed in any one of the preceeding Claims, wherein each pin has, projecting from the pin at or adjacent that one of its within the insulating plug body, an integral spigot which protrudes through a hole in one of a number of tabs of metal or metal alloy, each directly or indirectly electrically connected to one of the cable conductors, and wich is so distorted that the tab is permanently clamped to the pin.

5. An electric plug assembly as claimed in any one of the preceeding Claims in which the or a metal tab is indirectly electrically connected to one of the cable conductors, wherein the metal tab is spot welded or otherwise permanently electrically connected to one of two resilient clips for reception of a cartridge fuse.

6. An electric plug assembly as claimed in any one of the preceding Claims in which the or a metal tab is directly electrically connected to one of the cable conducrors, wherein the plug pins protrude through holes in a preformed body of electrically insulating material, and a moulded plug body of electrically insulating material wholly or partially encapsulates the preformed body and the plug pins and associated conductor connections with an appropriate length of each pin protruding from the plug assembly and is permanently bonded to the insulating covering of an adjacent part of the length of cable.

7. An electric plug assembly as claimed in any one of the Claims 1 to 5, wherein the plug pins protrude through holes in one of two preformed shells of electrically insulating material, which shells are welded or otherwise permanently secured together to form the insulating plug body housing the permanent electrical connections between the plug pins and the electric conductors of the flexible insulated multi-conductor cable.

8. A three pin electric pug assembly comprising an insulating plug body from which three plug pins project and a length of flexible insulated multiconductor cable whose electric conductors are permanently electrically connected to the associated plug pins, wherein the live pin is permanently electrically connected to a resilient fuse clip substantially as hereinbefore described with reference to and as shown in the accompanying drawing.