GB2176348A - Electrical accessory fixing systems - Google Patents

Abstract

An electrical accessory box for mounting of an outlet accessory to ensure secure location thereof comprises an open-topped box (10,50) having at opposite sides (10A,B; 50A,B) slots 16A,B; 56A,B for secure attachment thereto of wing (12,52) which, when so attached, afford substantial engagement surfaces for the accessory. The side walls are slotted through their thickness and from said open top to receive T-shaped (12T) or L-shaped (52T) extensions from the edges of the wings. Wings (52) which are moulded integrally with box 50 are snapped off at thinnings (62A, 62B) before use. Outlet accessory plates (20; 30) are also proposed for use with such a mounting box to provide the thinnest viable surface plate thickness of its periphery (20F) whilst providing a customary thickness at screw accommodating bosses (24) by rearward extensions thereof from the accessory plate or rearward recessing of an outlet accessory recess well (38). <IMAGE>

Description

SPECIFICATION Electrical accessory fixing systems This invention relates to fixing systems for electrical accessory plates and arises from considerations applying to use ofthe plug-and-sockettype connection system proposed in our patent specification no.

21 39433A.

Characteristics ofthat connection system relevant to this invention are attainment of secure location of a socket plate relative to a mounting surface in a manner best suited to engagement therewith of a plug unit in another accessory, for example a wall light bracket which presents particular problems, both in relation to required load-bearing capability and in relation to attaining desired close proximity of the bracket at its junction with the mounting surface.

It is amongst the objects ofthis invention at least to mitigatethe adverse impactof one ormore of such problems.

According to one aspect of this invention, an electrical accessory box for mounting of an outlet accessory, especially socket plates as aforesaid, is open-topped and formed at opposing sides for secure attachmentthereto of wing-like parts which, when so attached, afford substantial engagement surfaces for the rearofa hollow wall panel relative to a hole in which the box andean associated outlet accessory are to be fixed.

In a preferred embodiment, the walls of said opposing sides are slotted clearthrough theirthick ness and from said open top ofthe box and to a prescribed distance therefrom that is related to panel thicknesses,andthewingshavegenerallyT-or L-shaped extensions from their edges to be proximate said opposed sides ofthe box.

The prescribed distance, after taking account also of the thickness ofthe wings is preferably such that the open top ofthe box is inset in said hole ofthe panel with edges of that hole then clamped between the wings and an outlet accessory base or plate.

It is satisfactoryforthewings to extend along half or more ofthe lengths of said opposed sides ofthe box, preferably substantiallythe full lengths thereof, and for said slots and T-or L-shaped extensions to be spaced along such lengths in a symmetrical manner.

It is further advantageous for the wings to have reinforcing ribs on their undersides as affixed to the box and extending from their edges proximate said opposite sides ofthe box acrosstheirwidths to or towards their distal edges.

Thewings hereof may, atleast if of suitable plastics material, be moulded integrally with the box for breaking off to use or discard.

According to anotheraspect of this invention an open-topped electrical accessory mounting box, which may be a box ofthe first aspect, has accessory affixing screw locators, typically threaded bosses or studs upstand from its bottom, that accept rearward extension of an outletaccesory plate to be affixed thereto atthe position of locating screw holes and thereby permit thinnest viable surface plate thickness as same extends beyond said boxovera surface relative to which mounting is made orto be made.

In one embodiment, the outlet accessory plate is of standard size, preferably suiting an architrave box, andits only inset corresponds to accepting a socket unit body, such inset being flanked by screw accom modating bosses further rearwardly extending, Then, and advantageously, a customary 5 or 6 millimetre thicknessfor a surface-mounting accessory plate is attainable at said bosses, but peripheral extension of the plate to go overthe mounting surface to be overlapped can be of much less thickness, say 1 or 2 millimetres.

For our aforementioned system, that, of course, requires a non-customary socket plate, i.e. one of reduced peripheral thickness.

In another embodiment of the second aspect of this invention, the outlet accessory plate is dished sub stantially centrally and further apertured within such dishing to acceptthe whole of a normal plate thickness and rearward projecting body, respectively, and still present a peripheral portion of desired thinness.

The plate of either such embodiment may be provided as part of a fixing kit with the wings ofthe first aspect ofthis invention, even as a conjoint, break-offtype moulding.

Specific implementation of embodiments of this invention will now be prescribed by way of example, with reference to the accompanying drawing, in which: Figure lisa perspective view of an architrave-size accessory mounting box 10 and associated wings 12A,12B; Figures 2,3 and 4 are top, part sectional elevation, and bottom views of a first socket plate 20; Figure 5 is a perspective view of a second socket plate 30; and Figures 6,7,8 and 9 are top plan, end elevation, longitudinal section on X-X of Figure 6, and bottom part plan views of a preferred variant box 50 and wings 52A,52B.

Referring further to the drawing,the electrical accessory mounting box 10its of open-topped struc- ture with long opposing sides 1 0A, 1 0B and shorter ends 1 OC, OD. One ofthe ends (10C) is shown as apertured at 14for entry of mains wiring. Such entry 14 may be of a knock-outtype and be provided as such at each end of the box 10, even at opposite positions in its sides 1 0A, OB. Slots 1 6A, 1 6B are shown extending from the open top of the box 10 in each ofthe opposing sides 1 0A, lOB at spaced positions, actually shown close to the ends of those sides, though such is optional.Upstanding from the closed bottom 1 OE of the box 10 aretubular bosses orstuds 18C,18D at standard spacings for accessory mounting screws into threadings of the interiors ofthe bosses or studs 18C, 18D, orself-tappingthereinto.

The wings 12A, 1 2B are actually identical and each are of an overall length substantially equal to that of the long opposite sides 1 0A, 1 0B ofthe box 10, though they could be shorter if desired. Each ofthe wings 1 2A, 12B is of substantial width, typically a quarter to a half of the width of the box 10, but could be wider if desired.Each ofthewings 12A, 12B has tooth-like extensions 1 2Tfrom its side to be proximate the sides 1 0A, 1 0B ofthe box 10 when fitted thereto, which extensions 1 2T are shown in Figure 1 as being of T-shape in plan,though they couid equallywell be L-shaped, and are positioned and sized astotheir stems or limbs connected to the wings 12A, 12B to fit snugly into the slots 16A, 16B ofthe box 10.Attheir undersides 12U, the wings 1 2A, 1 2B further have ribs 12R extending flush downwardly from the same edges as the teeth 1 2T and also away fromthose edges.

When fitted to the box 10, the wings 12A,12B are a snug supported fit with the teeth 1 2T in the slots 1 6A, 1 6B and ends ofthe ribs 1 2R against box sides 1 OA, 1 OB, such fitting being indicated in the detail sectional view of Figure 1 A also showing only short protrusion ofthe box sides 1 OA, lOB above the wings 1 2A, 1 2B, i.e.to its open top edge lOT. Such protrusion to 10T is less than the normal thickness of a panel 40,for example plasterboard, into an aperture ofwhich the box 10 isto befitted.

Turning tofigures2to Athesocket unit plate20 thereof has a thin peripheral flange 20Fabout a central aperture 22 between underside wells orthickenings 24A, 24B serving as bosses with apertures 26A, 26B for fixing screws. The spacing ofthe holes 26A, 26B corresponds to the bores ofthe studs or bosses 1 8C, 18D ofthe box 10. The central aperture 22 has a flange 22Fformed within a strengthening skirt 22S running from the screw-hole bosses/wells 24A, 24B aboutthe aperture 22 and theflange 22F.Theflangeservesto take a rebated edge of afront plate of our preferred socket units, see also locating formation 22Lwith the main body ofthe socket unit proturding rearwardly and its said front plate flush with the upper or front surface 20U ofthesocketunft plate 20.

Fragmentally, Figure lAfurthershows the socket unit plate flange 20F clamping between it and a said wing 12A, 12B, on the panel 40 about its aperture 40A assumed sized to take the box 10. It will be appreciated that the thickness oftheflange 20F is a matter of choice and can be very much thinner, typically 1 to 2 mm,thannormalsocketunitmounting plate,typically - 5 to 6 mm, and so give a socket unitfront surface that is much nearerflush with a surface in which it is mounted orto be mounted, which is particularly advantageous for affixing wall brackets via feet carrying plug units forthe socket units.The socket mounting plate of Figures 2 to 4 is thus an alternative to the normal socket plate and will usually have a socket unit affixed therein, say by welding.

Another socket mounting plate 30 is shown in Figure 5, again with a thin peripheral flange 30F, and with acentral aperture 32to acceptthe rearward extension of a socket unit body from its normal socket mounting plate, see 34 in the fragmental section of Figure 5A. Such a latter plate (34) is, in fact, accommodated in a well 38 of the plate 30 aboutthe aperture 32 and having screw holes 36A, 36B to register with the bosses orstuds 18C, 18D ofthe box 10 of Figure 1.The whole plate unit 30 of Figure5 is convenientlyformed from the same thickness of material as its flange 30F, with the studs or bosses 1 8C, 1 8D suitably inset so that there is still a clamping action relative to edges of a larger hole 40B in the panel 40 into which flush affixing is required.

Turning to Figures 6 to 9, parts generally equivalent to those of Figure 1 are given references advanced by 40, i.e. '50' (box) is equivalentto '10' (box). Preferred variantsinclude a short upstanding side extension 58D from the side of the screw-fixing stud or boss 58B and aperturedfortaking an earth connection provision (not shown); a more outwardly inclined end 50C with cable feed aperture 54; showing of fixing holes 60A,60B(which mightbeelongatedand/orangled)for the box 50 itself, saywhere fixed against a block in the hollow wall concerned or in a solid wall (without wings 52); moulding of the wings 52A,52B integral with the box5oforsnapping offatthinnings62A,62B; and variantshapeofthe wings 52A, 52B to extend between the slots 56A, 56B with fitting therein and L-shaped teeth 52T.

It will be appreciated thatthe boxwith wings fitted can be entered into a hole in a hollow panel either on string and pulled down into place and/or by using a screw in one ofthe studs or bosses ofthe box, and securing thesocketunit mounting plate to the other stud or bossfirstafterwiring up. Cable entrytothe box through the illustrated hole can have its wires splitto each side ofthe nearest stud or boss, ortaken further into the box at least if that stud or boss is shortened.

Itwill further be appriciated that other cable entry provisions can be made to the box, including knockouts, indeed the shown holecould itself be as a knock-out.

Its also proposed to provide onthe undersides of each ofthe wings 12,52, a boss (not illustrated) to retain a fixing screw for carriage and packaging purposes. The boss is say circular in cross-section and slightlytapered toward the free end, and slotted from theendto receive grippinglythe retaining screwso that it can be held in a position parallel to the wings and preferably extending there-along. The slot is conveniently tapered diversing to thefree end ofthe boss.

Claims (18)

1. An electrical accessory boxfor mounting of an outlet accessory, is open-topped and formed at opposing sides forsecure attachment thereto of wing-like parts which, when so attached, afford substantial engagementsurfacesforthe rear of a hollowwall panel relative to a hole in which the box and an associated outlet accessory are to be fixed.

2. An electrical accessory box as claimed in claim 1 in which the walls of said opposing sides are slotted clearthrough theirthickness andfrom said open top of the box and to a prescribed distance therefrom that is related to panel thicknesses, and the wings have generally T- or L-shaped extensions from their edges to be proximate said opposed sides ofthe box.

3. An electrical accessory box as claimed in claim 2 in which the prescribed distance, after taking account also ofthe thickness ofthe wings is such that the open top ofthe box is inset in said hole ofthe panel with edges ofthat hole then clamped between the wings and an outlet accessory base or plate.

4. An electrical accessory box as claimed in any one of claims 1,2 or3in which the wings extend along half or more ofthe lengths of said opposed sides of the box,

5. An electrical accessory box as claimed in claim 4 in which the wings extend along thefull lengths of said opposed sides of the box.

6. An electrical accessory box as claimed in claim 2 or anyone of claims 3,4 or 5 when appendantto claim 2 in which said slots and T- or L-shaped extensions are spaced along such lengths in asymmetrical manner.

7. An electrical accessory box as claimed in any preceding claim in which the wings have reinforcing ribs on their undersides as affixed tothe boxand extending from their edges proximate said opposite sides ofthe box across their width to ortowards their distal edges.

8. An electrical accessory box as claimed in any preceding claim in which the wings are moulded integrally with the box for breaking offdueto use or discard.

9. An open-topped electrical accessory mounting box has accessory affixing screw locators, upstanding from its bottom, that accept rearward extension of an outlet accessory plate to be affixed thereto at the position of locating screw holes and thereby permit thinnest viable surface plate thickness as same extends beyond said boxoverasurfacerelativeto which mounting is made orto be made.

10. An open-topped electrical accessory mounting box as claimed in claim 9 in which the screw locators are threaded bosses or studs.

11. An accessory mounting box as claimed in claim 9 or lOin which the outlet accessory plate is of standard size, and its only inset corresponds to accepting a socket unit body, such inset being flanked by screw accommodating bosses further rearwardly extending.

12. An accessory mounted box as claimed in anyone of claims 9, 10 or 11 wherein a customary thickness fora surface-mounting accessory plate is attainable at said bosses, but peripheral extension of the plateto go overthe mounting surfaceto be overlapped is of much less thickness.

13. An accessory mounting box as claimed in claim 12 in which the customary thickness is ofthe order of 5 or 6 millimetres and the peripheral extension of the plate has a thickness ofthe order of 1 or2 millimetres.

14. An open-topped electrical accessory mounting box as claimed in claim 9 or lOin which theoutlet accessory plate is dished substantially centrally and furtheraperturedwithin such dishing to acceptthe whole of a normal plate thickness and rearward projecting body, respectively, and still preset a peripheral portion of desired thinness.

15. An electrical accessory box constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawingsoffiguresl and lAorfigures6to9.

16. An outlet accessory plate constructed and arranged substantially as hereinbefore described with reference to and as illustrated in figures2to4orfigure 5.

17. An electrical accessory box as claimed in any of claims 1 to 8 in which at least one of the wings has at least one boss extending from its underside to retain a fixing screw.

18. An electrical accessory as claimed in claim 17 in which the boss has a tapered slot is from the end thereof serving to retain the fixing screw.