GB2264595A - Electrical accessory mounting - Google Patents

Abstract

Mounting device for an electrical accessory body (10) relative to an apertured plate or panel includes shroud means having first and second parts both fitting about said body (10) and interfitting retainingly together. In figure 4 the first part (32) can fit inside and snap retainingly engage plate or panel aperturing. The second part (34) can fit retainingly to the accessory body by latches (36A, B) engaging flanges (35A) and to the first part (32) by latches (39). In fig 5, the first part (130) is in two sections that sandwich the plate or panel against springs (143, 144) and snap fit together at (140, 135). In this case, the second part (134) is optional. Further disclosure relates to a facia plate for a wall box, the plate comprising a framework attached to the box by offset screws and snap receiving a recovering, apertured plate. <IMAGE>

Description

TITLE: ELECTRICAL ACCESSORY MOUNTING ETC DESCRIPTION This invention relates to electrical accessories, particularly to mounting same relative to apertured plates or panels.

This invention arises in relation to development of electrical accessories for consumer sides of mains distribution installations, specifically accessories comprising bodies capable of association with spaced flanges engaged by movable retention means of or associated with the accessory body. Such spaced flanges may be of inverted-top-hat section mounting rails of busbar-intrunking distribution systems or of mounting inserts in other accessory mounting boxes, see our co-pending applications Nos GB9113297.7, EPA91305606.5 and EPA 91303434.4.Whether as switches or spur units or socket outlets or whatever, such accessories will normally be presented at their tops or fronts through apertures in cover plates that are securable to the aforesaid trunking or to access provisions such as boxes along its length, or to said other accessory mounting boxes (whether of surfacemounted or recess-mounted types). Such electrical accessory provisions enable a coherent modular range of accessories having bodies to which access for mounting/demounting and wiring or other purposes is available by removing the aforesaid cover plates. However it is now desired to further extend the ranges of application of such accessories, particularly to mounting relative to any apertured plates or panels, and it is an object of this invention to facilitate doing so.

According to one aspect of this invention, there is provided, for mounting of an electrical accessory body to an apertured plate or panel, mounting shroud means comprising first and second parts both fitting about the body, the former to be inside aperturing of the plate or panel and retainingly to engage the plate or panel, and the latter to fit retainingly to the body, the first and second parts further inter-fitting retainingly together.

Retaining fitment to the plate or panel can be by flanging of said first part engaging an outer surface of the plate or panel, and resilient formation(s) of that first part engaging an inner surface of the plate or panel.

A single said first part could extend all round an upper region of the accessory body and its flanging may cover all of edging of the panel or plate about the aperture into which the accessory concerned is to be fitted.

Retaining interfitment between the first and second parts can be by way of complementary formations thereof, conveniently involving resilience. A single said second part could extend over a lower region of the accessory body and over- or under-lap the first part or parts at positioning of said complementary formations.

Retaining fitment to the accessory body can be by movable latches of the body part that engage said second part, conveniently, for accessories in relation to which this invention has arisen, latches that would otherwise secure the accessory body to said spaced flanges. Suitable such latches are of swinging stirrup type and would fit about or beyond said second part or parts.

Use of a single said first part and a single said second part can combine to result in a plate or panel mounting shroud that may enclose substantially all of the body of the accessory below the upper surface of the top of the accessory except for wiring access, clearances for latches, and access to any separation means for the body and top of the accessory.

An alternative to said first part, and constituting another aspect of this invention, is two-part structure in itself, and for its two parts retainingly to fit together, with edging of aperturing of the plate or panel then between them; preferably with resilient compliance between them as to their spacing, thus to accommodate different thicknesses of the plate or panel.

Retaining fitment together can be by snap-fitting of complementary formations of the two parts, say as teeth and indents. In one embodiment, an upper or outer one of the two parts fits inside a lower or inner other of the two parts, and it is convenient for the latter to have interior teeth formations and for the former to have exterior indent formations.

Resilient compliance can be by angled arms extending from a or said lower or inner of the two parts. Such arms may abut and be flexed by panel or plate edging itself engaged by flanging of a or said upper or outer of the two parts. The flanging is conveniently part or extension of flanging engaging the plate or panel, and the angled arms are conveniently in pairs extending from exterior ribbing of the lower or inner of the two parts.

It is preferred for the lower or inner of the two parts to have aperturing for wiring purposes relative to entries to an accessory*within the two parts.

Retention of a or said accessory within the two parts can be by cooperating formations, conveniently interior indents in the upper or outer of the two parts and exterior toothing of the accessory. In that case, the abovementioned second part is not necessary for plate or panel mounting. However, where such second part is employed, there is no need for accessory retention provisions beyond inward flanging of the upper or outer of the two parts; and the second part can engage the accessory and retainingly fit to the inner or lower of the two parts, say onto said ribbing.

It is actually feasible for mounting shroud means hereof to be used relative to a cover plate otherwise intended for finishing a modular accessory unit mounted in a mounting box or trunking of a busbar-in-trunking system.

Then, the result can be an electrical accessory unit attached to its cover plate and thus mountable to standard or other mounting boxes or means in the same way as hitherto. There would be a requirement to modify a preferred and itself inventive feature of such cover plate provisions made by way of a frame part and a fascia part fitting inside the frame part, specifically involving the frame part ordinarily being secured to the accessory unit at positions other than corresponding to standard screwsecurement to standard accessory mounting boxes. The required modification could be provision for additional or alternative securement at such standard positions, say as an alternative or additional pair of screw passage holes.

No problem arises for additional such holes as all holes would be covered by the fascia part.

Specific implementation will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a front view of installation in a plate or panel; Figure 2 is an assembled view of the exploded parts of Figure 4; Figure 3 is a mainly end, but part sectional, view of that installation; Figure 4 is an exploded view of an electrical accessory; and a two part mounting shroud; Figure 5 is an exploded view of a three-part mounting shroud; Figure 6 is an exploded view of a two-part upper or outer mounting shroud provision; Figure 7 is an exploded view of a switch of our modular range; Figure 8 shows progressive assembly thereof; Figure 9 shows variant cover/face-plate provisions; Figures 10A,B,C are detail plan section and specific views of a cover plate tooth; Figures llA,B,C are detail plan, section and specific views of a cooperating capture formation of a frame part;; Figures 12A,B are detail views of another cover plate tooth formation and Figures 13A,B are - detail views of a- cooperating capture formation of frame part Referring first to Figures 1 to 4, an electrical accessory is shown at 10 as a fused spur unit specifically as coming from a modular range such as of our aforementioned co-pending patent applications. The accessory 10 could equally well be a switch or a socket or whatever. It has a lower body part 12 housing electrical connection parts, and a top body part 14 cooperating therewith and shown interfitting by way of cooperating latching parts at each end, see hanging loop 16 and tooth 18 for one end.However, it will be appreciated that this invention is applicable to any self-contained electrical accessory module, and the term "body" as used herein can include both of the lower body part 12 and the top body part 14 of what is shown in the drawings.

For fitting to an apertured plate or panel, as at 22 in unspecific sheet 20 (that could have any configuration with aperture 22) of Figures 1 and 2, the accessory unit 10 is associated with a mounting shroud 30 comprising a first part 32 to go around an upper region of the unit 10, and a second part 34 to go over a lower region of the unit 10.

Specifically, the first part 32 is intentionally a snug fit about sides and ends of the top body part 12, and the second part 34 also fits snugly under and up sides of the lower body part 14. Ends of the first part 32 have recesses, see 33 for one end 31, to clear the latching parts 16, 18, and stop short of wire entries to the lower body part 14. Ends of the second part 34 are open above outwardly directed flanges 35A,B for retaining engagement by swinging stirrup-shaped latches 36A,B of the accessory unit 10.Sides of the second part, also well 37 in its bottom, stop short of the latches 36A,B in their flange engaging positions. (It will be appreciated that the latches 36A,B swing outwardly past bottom end edges of the lower body part in their non-flange-engaging positions.) Sides of the first part 32 are shown with holes 38 for upstanding toothed formations 39 of the second part 34 that can go under the sides of the first part and retainingly latch in the holes 38, say relying on resilience of moulded plastics parts.

Flanging 45 of the first part extending outwardly of its topmost edge engages over the edge of the mounting aperture of the plate or panel 20.

It will be appreciated that the flanging 45 need not be continuous and fully extensive, and that the first and second parts 32,34 need not be substantially continuous.

Indeed, the first and second parts 32,34 could be each or either in two or more component or separate parts, say one at or near each end of the accessory unit 10.

Basic features are only retaining engagement by the or each first part with exterior surface of the plate or panel, and with aperture edging and/or interior surface of the plate or panel; plus inter-engaging retainingly of the or each first part with the or each second part; and retaining engagement of the or each second part by latching means between same and the body of the accessory unit.

In the illustrated embodiment, the flanging 45 is substantially flush or at least not proud of the top surface of the accessory unit 10, but that is not essential. Indeed, the flanging 45 can have any desired nesting and/or decorative effect relative to the accessory lqunit 10. Then flanging 45 is generally preferred, and may be coloured the same as or different from the accessory unit top, or the sheet, plate or panel 20.

It is even feasible for a plate 20 to be of an accessory cover provision that involves an outer frame part and an inner cover or fascia part, i.e. using the aforesaid modular accessory units without spaced-flange mounting therefor.

Referring to Figure 5, the first part 30 just described is effectively replaced by a two-part structure 130 having a lower or inner part 131 and an upper or outer part 132. For housing an accessory that is generally rectangular in plan, the upper or outer part 132 is shown with spaced depending long side walls 133 with indentings 135 near each end. The indentings 135 will be from the outside of the side walls 133, but need not be through holes as actually shown. The side walls 133 fit within the lower or inner part 131 which is also shown rectangular and has interior teeth formations 140 of its long sides to engage retainingly in the indentings 135. Short sides of the lower or inner part 131 have wire-entry holes 141 for the accessory (not shown).

The lower or inner part 131 also has exterior ribbing 142A,B of its long sides from which, and those sides generally, pairs of angled arms 143A,B and 144A,B are shown extending towards flanging 145 of the upper or outer part 132. Resilient compliance afforded by flexure of the arms 143,144 against edging of aperturing of a plate of panel below the flanging 145 assures stable and rattle-free fitting to various thicknesses of apertured panel or plate.

The flanging 145 conveniently also extends at 145A inwardly of the side walls 133 so as to aid capture of the accessory in its mounting thereto utilising a part 134 generally equivalent to the second part 34 described for Figures 11 to 4. The part 134 has outwardly directed flanges 135A,B for stirrup-type latches (not shown), an open well 137, and edge toothing 139 of its side walls to snap-fit into indentations (shown as through-holes) 147.

The parts 131, 132' of Figure 6 are the same as the parts 131, 132 of Figure 5 save that the upper or outer part 132' has interior indentings 146 of its side walls to latch directly to exterior formations of an accessory. The structure of Figure 6 can be used for plate or panel mounting without a stirrup latching part 134.

Turning to Figures 7 to 13, such an outer frame is designated 50 and has an upstanding edge 52 all round. It is shown apertured 54 for an accessory top and can have holes at 56A,B conventionally disposed to connect to conventional accessory mounting boxes. Ordinarily, though, holes at 18A,B are preferred, for other and originally intended applications (as will be described). An inner cover or fascia part 60 is also apertured at 62 for the accessory top and is latchingly associated with the frame 50 by way of lugs 66A,B and holes 68A,B at one side, and lug 69A and hole 69B at the opposite side, with slot 69C to permit removal using a flat-head screwdriver blade.

Such an outer frame and inner or fascia plate latching arrangement is not new in itself, but there is merit in offsetting the attachment holes 58A,B from normal mounting box positions, at least in application to a range of modular accessory units as in our aforementioned patent applications. As shown exploded in Figures 7, 8 and 9, a flange-affording insert 70 is normally separately attached at the standard accessory box screw fixing provisions 72A,B. However, the whole of the outer frame/inner cover arrangement is then removable without disturbing the accessory unit mounting as such.

Also, use of rounded and square or much more square corners for the inner or fascia plate and outer frame plate, respectively, is advantageous in avoiding damage to the inner or fascia plate prior to assembly and/or during installation or at other times afterwards that it is removed, as well as affording a particularly satisfying effect aesthetically in the particular detail illustrated.

Claims (17)

1. Mounting device for an electrical accessory body relative to an apertured plate or panel, comprising shroud means having first and second parts both fitting about said body, the first part to fit inside aperturing of said plate or panel and retainingly to engage said plate or panel, and the first and second parts interfitting retainingly together.

2. Mounting device according to claim 1, wherein the second part has an extent to go round a lower part of said accessory body, and there is overlap between the first and second parts.

3. Mounting device according to claim 1 or claim 2, wherein said interfitting between the first and second parts involves cooperating formations thereof.

4. Mounting device according to claim 3, wherein said interfitting between the first and second parts involves resilience of the cooperating formations.

5. Mounting device according to any preceding claim, wherein the first part has an extent to go all round an upper region of said accessory body.

6. Mounting device according to any preceding claim, wherein the first part has flanging to engage outer surface of said plate or panel.

7. Mounting device according to claim 6, wherein said flanging has an extent to cover all of edging of said plate or panel about its aperture to receive said accessory body.

8. Mounting device according to claim 6 or claim 7, wherein the first part has one or more resilient formations to engage inner surface of said plate or panel.

9. Mounting device according to any preceding claim wherein the second part fits retainingly to said accessory body.

10. Mounting device according to claim 9, wherein retaining fit of the second part to said accessory body is by way of movable latches associated with said accessory body.

11. Mounting device according to claim 10, wherein said movable latches are of swinging stirrup type carried about and beyond the second part.

12. Mounting device according to any preceding claim, wherein the first and second parts combine to enclose substantially all of said accessory body below its upper or top surface except for wiring access, any required clearances for said latches and any required access to separation means for said body and a top or cover part of said accessory.

13. Mounting device according to any preceding claim, wherein the first part is itself of two-part structure with its one and other parts fitting retainingly together, with edging of aperturing of said plate a panel between the one and the other part.

14. Mounting device according to any one of claims 1 to 8, wherein the first part fits to said accessory body and said interfitting of the first and second parts together is with edging of aperturing of said plate or panel between them.

15. Mounting device according to claim 12 or claim 13, wherein the one or first and the other or second parts have between them means for presenting resilient compliance as to -their spacing so as to accommodate to different thicknesses of said plate or panel.

16. Mounting device according to any preceding claim, wherein said resilient compliance is by way of angled arms extending from the other or second part towards the one or first part to engage on the inner surface of said plate or panel.

17. Mounting device substantially as herein described with reference to and as shown in the accompanying drawings.