GB2276047A

GB2276047A - Electrical outlet earth strap arrangement

Info

Publication number: GB2276047A
Application number: GB9404747A
Authority: GB
Inventors: David Langman Cook
Original assignee: PDL Holdings Ltd
Current assignee: PDL Holdings Ltd
Priority date: 1993-03-11
Filing date: 1994-03-10
Publication date: 1994-09-14
Anticipated expiration: 2014-03-10
Also published as: HK1000300A1; GB9404747D0; NZ247121A; GB2276047B

Abstract

An electrical outlet (1) in which contact assemblies and an earth contact and earth strap (10) arrangement engage with the rear of a front plate (2). The front plate (2) includes fixing screw apertures (6, 7) arranged to allow the free end of the earth strap (10) to be located to form a contact seat in one of the fixing screw apertures (6, 7). The earth strap (10) may have a hooked end (9) and the fixing screw apertures may include recesses (8) which are shaped to receive said hooked end (9). The outlet (1) may include a switch arrangement. <IMAGE>

Description

IMPROVEMENTS IN/OR RELATING TO METHODS OF MANUFACTURING ELECTRICAL OUTSETS AND/OR ELECTRICAL OUTSETS MANUFACEURED THEREBY This invention relates to methods of manufacturing electrical outlets and/or electrical outlets manufactured thereby.

The manufacture of electrical outlets must be kept to a high standard of safety and reliability. The present invention is concerned with the manufacture of electrical outlets switched or unswitched in a more effective manner without reducing either the safety or the reliability.

The assembly steps as will be set out hereafter include fitting an earthing strap in the outlet without any separate jointing or riveting in the fixing screw aperture.

In one aspect the invention may consist in a method of forming an electrical outlet having a front mounting plate with plug sockets and mounting screw apertures there through and a contact holding base engagable with the rear of the mounting plate said method comprising the steps of assembling the contact assemblies on or within the base with the earth contact assembly including an earth strap engaging the base and contact assemblies with the rear of the front plate so that the contact assemblies operably align with the plug sockets and the free end of the earth strap engages within one of the apertures for a fixing screw to provide a contact seat upon which in use the fixing screw is seated to make an earth connection.

In a further aspect the invention consists in an electrical outlet comprising a front plate having plug sockets and mounting screw apertures formed there through a contact assembly holding base engagable with the rear of the front mounting plate said base adapted to receive the contact assemblies in operable location to align in use with the plug sockets in the front plate with said earth contact assembly including an earth strap arranged so that the free end thereof in use engages within one of the apertures for a fixing screw to provide a contact seat upon which in use the fixing screw engages to make an earth connection.

The invention consists in the foregoing and also envisages constructions of which the following gives examples.

One preferred form of the invention will now be described with reference to the accompanying drawings in which: Figure 1 is a front plate of a switched electrical outlet to meet British Standards; Figure 2 is a rear view of the outlet in the assembled position; Figure 3 is a sectional view showing the switch in more detail; Figure 4 is a further sectional view showing a contact assembly in more detail; Figure 5 is a view of the base and contact assemblies in place ready to be engaged with the front plate; Figure 6 is a detail showing the earth strap engaged in the fixing aperture and with the contact seat contacting the fixing screw; and Figure 7 is a detailed perspective view of the earth strap.

In the preferred form of the invention disclosed reference has been made to a particular plug configuration suitable for British Standards but it will be appreciated that the invention may be applied to a wide variety of electrical outlets irrespective of the Standard adopted. It may also be applied to a wide variety of electrical outlets both switched and unswitched and while the base and contact assemblies would be different the general principles as disclosed herein would remain the same.

The electrical outlet 1 has a front plate 2 through which are formed openings or sockets 3, 4 and 5 for the pins of a plug. The front plate also includes apertures 6 and 7 for the fixing screws. Apertures 6 and 7 are recessed to accommodate to the screw head as is more particularly shown in Figure 6. A further recess or channel 8 is formed to receive the hooked end 9 of the earth strap 10 as will be more particularly described hereafter.

A moulded plastics base 11 is designed to receive contact assemblies. In the example given a switched outlet is shown with the phase connection 12 supporting a shaped arm 13 having at the end thereof a V fold 14 (see Figure 3) to provide a fulcrum about which the switch member 15 may pivot establishing the make or break contact assembly 16 operable by the rocker assembly 17. The other contact is carried on a strap 18 which is shaped at 19 to form the recess for the phase pin.

A simple terminal connector and pin engaging contact 20 provides the neutral contact assembly.

The earth contact 21 has riveted thereto the earthing strap 10. All of these components may be assembled in position ready to be mounted on the front plate.

As will be seen from Figure 5, the earth strap comprises essentially an L shaped member with one arm of the L stepped back and having the hooked end 9 to engage in the recess in the aperture in the front plate for the fixing screw. The shape of this member will depend upon the configuration of the outlet but the broad principle is shown clearly in Figures 6 and 7.

Once the contact assembly has been formed on the base with the earthing strap in place the contact assembly is brought into engagement with the front plate with the hooked end of the earth strap engaging through the appropriate fixing screw outlet in the front plate. The earth strap is then moved back into place to engage in the recess 8 and when so located the mounting screws 22 are inserted to mount the contact assembly and base on the front plate.

In use when the fixing screw 23 is in place the head of the screw sits on the contact seat 9 of the earthing strap as is shown in Figure 6. This provides the required earth to the fixing screw without any separate assembly or riveting step between the earth strap and the fixing aperture.

For convenience the fixing screws 23 are carried on the back of the outlet as also are plugs 24 to engage in the recess above the placed fixing screw 23. For convenience the recesses to receive the earth strap are formed in each fixing aperture.

The present invention allows an electrical outlet switched or unswitched to be assembled more effectively without in any way impairing the reliability and safety of the outlet.

Claims

CLAIMS:

1. A method of forming an electrical outlet having a front mounting plate with plug sockets and mounting screw apertures there through and a contact holding base engagable with the rear of the mounting plate said method comprising the steps of assembling the contact assemblies on or within the base with the earth contact assembly including an earth strap engaging the base and contact assemblies with the rear of the front plate so that the contact assemblies operably align with the plug sockets and the free end of the earth strap engages within one of the apertures for a fixing screw to provide a contact seat upon which in use the fixing screw is seated to make an earth connection.

2. A method of forming an electrical outlet as claimed in claim 1 including forming the earth strap with a hooked end and positioned to engage through a fixing aperture in the front plate to provide a contact seat or the fixing screw when engaged through said aperture.

3. A method of forming an electrical outlet as claimed in claim 2 wherein the front plate has the aperture for the fixing screw shaped to receive the hooked end in a locating recess while still leaving an appropriate aperture for the fixing screw and allowing the earthing contact.

4. A method of forming an electrical outlet when performed substantially as herein described with reference to the accompanying drawings.

5. An electrical outlet comprising a front plate having plug sockets and mounting screw apertures formed there through a contact assembly holding base engagable with the rear of the front mounting plate said base adapted to receive the contact assemblies in operable location to align in use with the plug sockets in the front plate with said earth contact assembly including an earth strap arranged so that the free end thereof in use engages within one of the apertures for a fixing screw to provide a contact seat upon which in use the fixing screw engages to make an earth connection.

6. An electrical outlet as claimed in claim 5 wherein said base is arranged to have mounted thereon or therein the contact assemblies in a manner such that the contact assemblies and base can be brought into engagement as a unit for mounting on the rear of the front plate in an operable position.

7. An electrical outlet as claimed in claim 5 or claim 6 wherein the earth strap has a hooked end and the front plate has a recess associated with mounting screw aperture to receive the hooked end so that when in place the exposed surface of the hooked end provides a contact seat which is engaged by the head of the fixing screw when inserted into position to mount the electrical outlet.

8. An electrical outlet as claimed in any one of claims 5 to 7 wherein a switch may be incorporated in the base assembly and a switch aperture incorporated in the mounting plate to allow the rocker or other operating means of the switch to protrude through the front plate.

9. An electrical outlet when constructed, arranged and operable substantially as herein described with reference to the accompanying drawings.