GB2274218A

GB2274218A - Mounting electrical accessories in panels

Info

Publication number: GB2274218A
Application number: GB9400205A
Authority: GB
Inventors: Michael John Attridge; Grant Matthews
Original assignee: MK Electric Ltd
Current assignee: Novar ED&S Ltd
Priority date: 1993-01-09
Filing date: 1994-01-07
Publication date: 1994-07-13
Anticipated expiration: 2014-01-07
Also published as: SG48211A1; GB9300338D0; SA94140751B1; CN1092551A; GB2274218B; GB9400205D0

Abstract

An electrical accessory is mounted in a first or a second apertured support plate (1). The accessory may be inserted into the aperture (2) from the front in the case of the first support plate (1) and from the rear in the case of the second support plate. Resiliently deformable mounting latches (8, 12) may co-operate respectively with the first or second support plate (1) when the accessory is inserted into the aperture (2). The size of the body of the accessory and the size of the aperture (2) may be such that a plurality of accessories may be fitted side-by-side within the aperture (2). One latch set may be inwardly directed and the other outwardly directed (30, 31, fig. 8). The accessory may be provided with latches at opposite sides thereof. <IMAGE>

Description

MOUNTING ELECTRICAL ACCESSORIES This invention relates to mounting electrical accessories in or on a support plate and more particularly to an electrical accessory adapted to be mounted in or on an apertured support plate.

Electrical accessories, such as switches and plug sockets for household and commercial use commonly comprise plates of metal or plastics material which are attached to a wall or other supporting structure and which support the circuit elements of the accessory. A wide variety of accessories including switches and sockets, fixed connection units, fuse units and circuit breakers are wallmounted in this way, the circuit elements being attached to the back of the plate and being accommodated in either a box or an aperture in the wall behind the plate. As different accessories are generally of different shapes and sizes, each accessory requires a specific design of plate to support it. The elements of the accessory accommodating the working parts behind the plate may be integral with the plate or attached to the plate by screws.

In British Patent number 2194395 there is described a means whereby a single supporting plate may support a variety of interchangeable electrical accessories of different types, so that the type of accessory installed may be varied at will, but once installed in the plate the accessory cannot readily be removed from the plate without removing the plate from a box or surface on which it is mounted.The aforesaid British Patent describes and claims an assembly comprising a support plate provided with an aperture and at least one electrical accessory to fit in the aperture, the plate comprising projections extending into the aperture and abutting a rear surface of the accessory when the accessory is fitted in the aperture, and the rear surface of the accessory comprising rearwardly extending resilient prongs having outwardly directed flanges to engage a rear surface of the plate, so that the accessory may be inserted in the aperture while a force Is exerted on the prongs to deform them inwardly, and after release of said force the accessory is held in place by abutment of said projections with the accessory and by abutment of said flanges with the plate. The assembly of British Patent 2194395 has proved to be extremely successful in practice, but it requires the accessory to be inserted into the support plate from the front. In many situations, particularly with single wall mounted switches, this may not be convenient, and it would be desirable for the accessory to be inserted into the support plate from the rear. This is not readily achieved using the arrangement of British Patent 214395.

European Patent application number 0487893 discloses patching modules, each of which has inwardly displaceable snap fitting means located on three side faces thereof and divergent ramps arranged on the fourth surface so that the module can be snap fitted into a panel from either the front or the rear.

European Patent application number 0147828 discloses a connector housing having a body portion which is provided on four side faces thereof with inwardly resiliently displaceable holding fingers, the holding fingers being arranged such that the fingers on adjacent faces extend in opposite directions to each other to enable the connector to be snap fitted into a plate from either the front or the rear.

The present invention provides a system whereby an electrical accessory body design can be produced such that it can be mounted in a support plate either by insertion from the front or from the rear, depending on the type of support plate used in the desired application and whereby a plurality of accessories can be mounted in an appropriately dimensioned support plate. The system of the invention has improved versatility, can be simpler in construction and can be easily assembled, thereby reducing manufacturing, inventory and installation costs.

According to a first aspect of the present invention there is provided an electrical accessory adapted to be mounted in a first or a second apertured support plate, the accessory being adapted to be inserted into the aperture from the front in the case of the first support plate and from the rear in the case of the second support plate, and resiliently deformable mounting means adapted to co-operate with the first or second support plate when the accessory is inserted into the aperture to secure the accessory to the first or second support plate, the body of the accessory and the aperture in the first or second support plate being dimensioned such that a plurality of accessories may be fitted side-by-side within the aperture.

According to another aspect of the present invention there is provided an electrical accessory adapted to be mounted in a first or a second apertured support plate, the accessory being adapted to be inserted into the aperture from the front in the case of the first support plate and from the rear in the case of the second support plate, and resiliently deformable mounting means adapted to co-operate with the first or second support plate when the accessory is inserted into the aperture to secure the accessory to the first or second support plate, wherein said mounting means comprises at least one inwardly resiliently deformable prong and at least one outwardly resiliently deformable prong.

According to a further aspect of the present invention there is provided an electrical accessory adapted to be mounted in a first or a second apertured support plate, the accessory being adapted to be inserted into the aperture from the front in the case of the first support plate and from the rear in the case of the second support plate, and resiliently deformable mounting means adapted to co-operate with the first or second support plate when the accessory is inserted into the aperture to secure the accessory to the first or second support plate, wherein said mounting means are located at two opposed sides of the accessory.

The resiliently deformable mounting means may be attached to a support plate, or provided as a separate component, but preferably it is mounted on the body of the electrical accessory and most preferably integrally moulded therewith.

In a preferred embodiment of the invention the resiliently deformable mounting means is provided with locating features such that the electrical accessory is a snap fit in the aperture of the first or the second support plate, that is to say, the accessory is adapted to be received in or on the support plate by the application of gentle pressure against the resilience of the mounting means until the accessory snaps into place and is retained by the mounting means in its mounted position. For example, the resiliently deformable mounting means may comprise resiliently deformable prongs arranged on the body of the electrical accessory, and preferably located at opposed sides (preferably the ends) thereof. Preferably there is provided a first prong which is deformable towards the body to permit the accessory to be mounted on the first support plate, and a second prong which is deformable away from the body to permit the accessory to be mounted on the second support plate. Although, other orientations are possible, preferably the resiliently deformable prongs are mounted on the body in such a manner that they are forwardly directed, that is to say they face towards the front of the electrical accessory.

The invention further provider an assembly comprising an electrical accessory as hereinbefore defined in combination with a first support plate, the accessory being adapted to be inserted from the front of the first support plate, and an assembly comprising an electrical accessory as hereinbefore defined in combination with a second support plate, the accessory being adapted to be inserted from the rear of the second support plate.

Preferably, the first and second support plates each have an aperture adapted to receive the body of the accessory therein, and are provided with locating features which mate with corresponding locating features on the accessory body to ensure correct positioning. The first and second support plates may be of the same or different shape or construction. The first support plate is preferably provided with an aperture configured such that an edge region of the support plate adjacent the aperture co-operates with the resiliently deformable mounting means on the body of the accessory so as to secure the accessory within the aperture. Preferably the edge region of the first support plate adjacent the aperture is held between first and second resiliently deformable prongs of the mounting means so as to secure the accessory within the aperture.For example the first support plate may have an aperture provided with a cut-out portion defining a shoulder or shoulders on at least one edge region thereof, and the first prong may be resiliently inwardly-deformable, enabling the accessory to be pressed into the aperture, and such that it snaps back, when the accessory is in position, with a portion of the first prong abutting the rear surface of the first support plate behind the shoulder or shoulders of the cut-out portion. In this position, the edge region is preferably gripped on each side and held between the first prong abutting the rear surface and a portion of the second prong which abuts the front surface of the first support plate at an edge region of the aperture therein.

The aperture in the first support plate may be dimensioned to receive only one electrical accessory, the shape and dimensions of the aperture then corresponding to those of a single accessory, or the aperture may be dimensioned to receive two, three or more similar accessories side-by-side, all the accessories being held in the aperture by the same method. When more than one accessory is held in a single plate aperture, the accessories may be the same or functionally different. The width of the aperture may be a whole multiple of a single modular width and the or each electrical accessory may have a width equal to said modular width or a whole multiple thereof.

The second support plate may be provided adjacent the aperture with means for engaging with a second prong of the resiliently deformable mounting means so as to secure the accessory to the second support plate. For example, the second prong may be adapted to engage with a rearwardly extending projection on the second support plate adjacent to the edge of the aperture. In a particularly preferred embodiment the second prong is provided with a retaining bar flanking an apertured or recessed internal region thereof, which region is adapted to receive an outwardlyfacing lug of a rearwardly-extending projection on the second support plate.

The aperture in the second support plate may be of any convenient size and shape to enable the electrical accessory to perform its function. Thus it may be configured to accommodate a switch rocker, or provide access for an electrical plug, in the case of an electrical plug socket.

Preferably retaining means is provided to prevent inward deformation of the second prong or prongs. Such means may comprise an apertured insert, extending across the front face of the accessory body, which may be clipped into position to hold out the second prong or prongs against inward movement.

Preferably the second prong is provided with a retaining bar flanking an apertured or recessed internal region thereof adapted to receive an engaging means which may comprise an outwardly-facing lug on the rearwardlyextending projection of the second support plate.

In the case of a front mounted electrical accessory, a tool may be provided to enable the accessory to be removed from the first support plate. In the case of a rear mounted electrical accessory, it will not in general be necessary to remove the accessory from the second support plate, although of course this can be done if so desired by applying leverage to the second prong.

The support plates themselves may be provided with circuit elements which cooperate in conjunction with the accessories mounted in the plate aperture. For example, the plate may be provided with holes forming a socket to receive the pins of a plug, the rear of the plate may support the terminals and other socket components for establishing electrical contact with the plug pins to connect the plug in a circuit, and an aperture in the plate adjacent the holes may accommodate a switch in the manner described above to open and close the circuit.

The support plates may be provided with holes to receive screws for attaching the plate to a box or a wall in known manner.

The invention thus provides a single and unique electrical accessory body design which can be used interchangeably with either of two novel support plate designs to provide an assembly which can be used in a wide variety of situations. Thus for example a simple wall switch for a lighting circuit can be constructed by attaching the switch body to the rear of a face plate having a hole through which the rocker switch can protrude.

In a more complex, modular, construction, a number of switches can be assembled on a support plate from the front in side by side relationship, and then surrounded by a face plate of the picture frame type.

The electrical accessory may be a one or two-way switch, particularly a rocker switch, a plug socket, a fixed connection unit, a fuse unit, a circuit-breaker, an indicator light, or like device.

Support plates and electrical accessories to be mounted on them according to embodiments of the invention will now be described with reference to and as illustrated in the accompanying Drawings in which: Figure 1 shows a front elevation of a rocker switch assembly according to the invention with portions of the switch body indicated by broken lines; Figure 2 shows the rocker switch assembly of Figure 1 in end elevation; Figure 3 shows the rocker switch of Figure 1 in side elevation, partly in section; Figure 4 shows a rear view of the rocker switch of Figure 1; Figure 5 shows a second embodiment of a rocker switch assembly according to the invention; Figure 6 shows the body of the rocker switch of Figure 5 in side elevation with the position of the wall mounted box illustrated by broken lines; Figure 7 shows the rocker switch body of Figure 6 in end elevation; and Figure 8 shows the rocker switch assembly of Figure 5 in exploded view and including a cover plate.

Referring to Figures 1 to 4, the rocker switch assembly comprises a support plate (1), of generally rectangular shape, having a rectangular aperture (2) therein. The support plate has fixing holes (3) for the introduction of screws or bolts for mounting the rocker switch assembly in the usual way. Extending through the aperture (2) is a switch rocker (4) which is pivotally mounted and activates a switch contained in the switch body (5). The body is provided with holes (6) providing access to terminals through which wires can be introduced and secured by means of threaded bolts (7).

At each end of the rectangular body (5) there are provided pairs of resiliently deformable prongs (8, 9) which are adapted to secure the body to different types of support plate. In the embodiment of Figures 1 to 4, the support plate is provided with rearwardly-extending projecting walls (10) having outwardly facing lugs (11), shown in Figure 2 and illustrated by broken lines in Figure 3. The inner resiliently-deformable prongs (8) have, as best seen in Figure 2, a retaining bar (12) carried by three prong supports (13) (the central prong support is concealed behind the outer prong (9)). The three prong supports and the retaining bar (12) define two apertures (14).In assembly the switch body is inserted to the rear of the support plate with the switch rocker extending through the aperture (2), and finger pressure is applied to push the inner prongs (8) against the lugs (11) on the rearwardly extending walls (10). This pressure deforms the resilient prongs (8) outwards so that the retaining bar (12) can pass over the lugs (11) until it snaps back against the wall (10). The switch body is then mounted on the support plate (1) and held by the combination of the retaining bar (12) and the lugs (11) which protrude through the apertures (14). In this embodiment the outer prongs (9) play no part in attaching the switch body to the support plate.

In Figures 5 to 8 there is shown a rocker switch assembly in which the switch body is inserted into the support plate from the front. The assembly of this second embodiment comprises a support plate (21) of generally rectangular shape, having a rectangular aperture (22) therein. On each end of the rectangular aperture (22) there is provided a cut-out portion (23) having shoulder regions (24). Within the aperture there is mounted a switch body (25) having a switch rocker (26) pivotally mounted thereon. The body (25) and switch rocker (26) are of the same construction as that shown in Figures 1 to 4.

The assembly is completed by an insert (27), the purpose of which will be explained later, and a face plate (28) having a rocker aperture (29). At each end of the rectangular switch body (25) there are provided pairs of resiliently deformable prongs (30, 31) for attachment of the switch body to the support plate (21).

In a first stage of assembly, the insert (27) is applied to the front of the switch body and pushed over the switch rocker (26). The insert has an aperture (32) (Figure 5) through which the switch rocker can protrude.

End regions (33) of the insert press against the resilient inner prongs (30) such that the insert is a press fit on the switch body (see Figure 6) and the end regions (33) act to prevent the resilient inner prongs (30) from being forced inwards. In the next step the switch body (25) is placed in the aperture (22) of the support plate (21) and pressed into place by applied finger pressure. The outer resilient prongs (31) are accepted into the aperture '23) and are resiliently deformed inwards as the switch body is pressed into place. As the prongs (31) pass through the aperture (22), a point is rehashed at which they can snap back into place when the shoulders (34) on the prongs (31) (see Figure 7) are beyond the shoulders (24) in the cut-out portions of the aperture of the support plate (21).Prong shoulders (34) then cooperate with shoulders (24) on the support plate to prevent the switch body from being moved forwardly of the support plate. Further rearward progress of the switch body through the aperture is prevented by the prongs (30) whose projections (35) contact the edge regions of the front face of the support plate (21). The switch body is then held between the shoulders (34) on prongs (31) and projections (35) on prongs (30). The assembly is completed by securing the support plate to a wall mounting box (36) (Figure 6) and securing the faceplate (28) to the assembly. In the assembled rocker switch assembly the switch rocker (26) protrudes through the aperture (29) in the faceplate (28) and can be operated in the usual way.

If it is desired to change the rocker switch, or to remove it for any reason, a tool may be used to deform the prongs (31) inwards thereby releasing the switch body from the support plate.

The invention provides an elegant and versatile system for mounting an electrical accessory on or in a support plate which provides maximum flexibility and allows a single accessory body construction to be used in a variety of situations.

The readers attention is directed to all papers and documents which are filed concurrently with this specification and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps or any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

Claims

1. An electrical accessory adapted to be mounted in a first or a second apertured support plate, the accessory being adapted to be inserted into the aperture from the front in the case of the first support plate and from the rear in the case of the second support plate, and resiliently deformable mounting means adapted to co-operate with the first or second support plate when the accessory is inserted into the aperture to secure the accessory to the first or second support plate the body of the accessory and the aperture in the first or second support plate being dimensioned such that a plurality of accessories may be fitted side-by-side within the aperture.

2. An electrical accessory adapted to be mounted in a first or a second apertured support plate, the accessory being adapted to be inserted into the aperture from the front in the case of the first support plate and from the rear in the case of the second support plate, and resiliently deformable mounting means adapted to co-operate with the first or second support plate when the accessory is inserted into the aperture to secure the accessory to the first or second support plate, wherein said mounting means comprises at least one inwardly resiliently deformable prong and at least one outwardly resiliently deformable prong.

3. An electrical accessory adapted to be mounted in a first or a second apertured support plate, the accessory being adapted to be inserted into the aperture from the front in the case of the first support plate and from the rear in the case of the second support plate, and resiliently deformable mounting means adapted to co-operate with the first or second support plate when the accessory is inserted into the aperture to secure the accessory to the first or second support plate, wherein said mounting means are located at two opposed sides of the accessory.

4. An electrical accessory according to any of the preceding Claims, wherein the resiliently deformable mounting means is mounted on the body of the electrical accessory.

5. An electrical accessory according to any of the preceding Claims, in which the resiliently deformable mounting means is provided with locating features such that the accessory is a snap fit in the aperture of the first or second support plate.

6. An electrical accessory according to any of the preceding Claims, wherein the resiliently deformable mounting means comprises resiliently deformable prongs arranged on the body of the electrical accessory.

7. An electrical accessory according to Claim 6, in which the resiliently deformable prongs are located at opposed sides of the body of the electrical accessory and comprise, on each side of the body, a first prong which is deformable towards the body to permit the accessory to be mounted on the first support plate, and a second prong which is deformable away from the body to permit the accessory to be mounted on the second support plate.

8. An electrical accessory according to Claim 6 or 7, in which the resiliently deformable prongs are mounted on the body in such a manner that they face towards the front of the electrical accessory.

9. An electrical accessory according to any of the preceding claims, wherein, the accessory has a body provided on at least one side with two forwardly directed resiliently-deformable prongs, a first inwardly-deformable prong and a second outwardly deformable prong, the accessory being adapted to be inserted from the front of a first support plate having an aperture adapted to receive the body of the accessory and configured such that an edge region of the first support plate adjacent the aperture can be held between the first and second prongs so as to secure the accessory within the aperture and the accessory being further adapted to be inserted from the rear of a second support plate having an aperture adapted to permit functional operation of the accessory and having means for engaging with the second prong so as to secure the accessory to the second support plate.

10. An electrical accessory according to any of Claims 7 to 9, in which the first prong has a portion thereof adapted to abut the rear surface of the first support plate at an edge region thereof and the second prong has a portion adapted to abut the front surface of the first support plate at an edge region of the aperture therein.

11. An electrical accessory according to any of Claims 7 to 10, in which the second prong is provided with a retaining bar flanking an apertured or recessed internal region thereof adapted to receive engaging means on the second support plate.

12. An electrical accessory according to any of Claims 7 to 11, in which retaining means is provided to prevent inward movement of the second prong.

13. An electrical accessory according to Claim 12, in which the retaining means comprises an apertured insert, extending across the front face of the accessory body, which may be clipped into position to hold out the second prong against inward movement.

14. An electrical accessory according to any of the preceding Claims, that is a one or two-way switch, a plug socket, a fixed connection unit, a fuse unit, or an indicator light.

15. An electrical accessory according to Claim 14, in which the one or two-way switch comprises a rocker switch.

16. An electrical accessory according to any of the preceding Claims, substantially as hereinbefore described and illustrated in the accompanying Drawings.

17. An electrical accessory substantially as hereinbefore described.

18. An assembly comprising an electrical accessory according to any of the preceding claims in combination with a first support plate, the accessory being adapted to be inserted from the front of the first support plate.

19. An assembly according to Claim 18, in which the first support plate has an aperture adapted to receive the body of the accessory therein, and is provided with locating features which mate with corresponding locating features on the accessory body to ensure correct positioning.

20. An assembly according to Claim 18 or 19, in which the accessory is a snap fit in the first support plate aperture.

21. An assembly according to Claim 19 or 20, in which the aperture is configured such that an edge region of the support plate adjacent the aperture cooperates with resiliently deformable mounting means on the body of the accessory so as to secure the accessory in the aperture.

22. An assembly according to Claim 21, in which the edge region of the first support plate adjacent the aperture is held between first and second resiliently deformable prongs of the mounting means so as to secure the accessory within the aperture.

23. An assembly according to Claim 22, in which the first support plate has an aperture which is provided with a cut-out portion defining a shoulder or shoulders on at least one edge region thereof, and the first prong is resiliently inwardly-deformable, enabling the accessory to be pressed into the aperture, and such that it snaps back when the accessory is in position with a portion of the first prong abutting the rear surface of the first support plate behind the shoulder or shoulders of the cut out portion.

24. An assembly according to Claims 22 or 23, in which the edge region of the first support plate adjacent the aperture is gripped between the first prong and a portion of the second prong which abuts the front surface of the first support plate at an edge region of the aperture therein.

25. An assembly according to any of Claims 18 to 24, in which the aperture in the first support plate and the body of the accessory are dimensioned so that a plurality of similar accessories may be fitted side by-side within the aperture.

26. An assembly according to any of Claims 18 to 25 substantially as described with reference to Figures 5 to 8 of the accompanying Drawings.

27. An assembly comprising an electrical accessory according to any of the proceeding claims in combination with a second support plate, the accessory being adapted to be inserted from the rear of the second support plate.

28. An assembly according to Claim 27, in which the second support plate has an aperture adapted to receive the body of the accessory therein, the aperture being adapted to permit functional operation of the accessory from the front of the second support plate.

29. An assembly according to Claim 27 or 28, in which the second support plate has an aperture adapted to receive the body of the accessory therein, and is provided with locating features which mate with corresponding locating features on the accessory body to ensure correct positioning.

30. An assembly according to any of Claims 27 to 29, in which the accessory is a snap fit in the second support plate aperture.

31. An assembly according to any of Claims 27 to 30, in which the second support plate is provided adjacent to the aperture with means for engaging with a second prong of the resiliently deformable mounting means so as to secure the accessory to the second support plate.

32. An assembly according to Claim 31, in which the second prong is adapted to engage with a rearwardly extending projection on the second support plate.

33. An assembly according to Claim 31 or 32, in which the second prong is provided with a retaining bar flanking an apertured or recessed internal region thereof, which region is adapted to receive an outwardly-facing lug of a rearwardly-extending projection on the second support plate.

34. An assembly according to any of Claims 27 to 33 substantially as described with reference to figures 1 to 4 of the accompanying Drawings.

35. An assembly comprising an electrical accessory and a first or a second support plate substantially as hereinbefore described.