AU8193698A - Electrical wall box - Google Patents

Description

4el" F P/00/011 Regulation 3.2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD

PATENT

LI I is 8$ fl n a 7i .1; .ii: 1: Name of Applicant: Address of Applicant: Actual Inventor: Address for Service: Concept 2000 Ply Ltd Unit 3 33 Hector Street Osborne Park Western Australia 6017 Australia Sergio Cotellessa Griffith Hack, Patent Trade Mark Attorneys, Level 6, 256 Adelaide Terrace, Perth, Western Australia 6000, Australia Standard Complete Specification for the Invention Entitled: ELECTRICAL WALL BOX Details of Associated Provisional Applications: Australian Provisional Application No PO 9206 dated 15 September 1997 The following is a full description of this invention, including the best method of performing it known to me: -2- ELECTRICAL WALL BOX The present invention relates to an electrical wall box, particularly, though not exclusively, for use in brick and masonry walls.

In order to facilitate the electrical wiring of brick and masonry walls it is necessary to cut recesses into the walls for the installation of electrical conduits. Electrical cables are passed through the conduits and routed to various electrical switches such as light switches and power point switches etc. The switches typically comprise an electrical wall box which is fitted into a cavity cut into the wall and a face plate :which can be screwed onto the wall box. During the construction of new houses, cavities are cut into the walls prior to rendering and plastering in order to receive the wall boxes. In the case of renovating existing plastered walls, the cavities are cut through the existing plaster, render and bricks. In both cases, after the wires have been routed into the wall box and prior to connection of the face plate, a plasterer will replaster the wall in the vicinity of the wall box.

In practice, the above process of installing wall boxes has several inherent deficiencies. One significant problem is that often during the plastering phase for brick walls, the wall box is completely covered with plaster. This results in plaster and render entering the wall box and, loss of the wall box. It is estimated that approximately 5% of wall boxes are lost in this manner. To subsequently find the wall box in order to complete the wiring and apply the face plate, an electrician will typically tap the wall and listen for differences in sound. However this can cause additional damage to the surrounding plaster resulting in a need for repair work thus increasing the overall building costs. Also, at times it is difficult to accurately align the wall boxes so that they sit flush or parallel to the surface of the wall.

It is an object of the present invention to provide an electrical wall box which can assist in overcoming one or more of the above noted disadvantages in the prior art.

-s 3 According to the present invention there is provided an electrical wall box adapted for insertion into a cavity formed in a wall, said wall box including: a box having a peripheral edge defining an opening over which a face plate can be connected; and, a plurality of coplanar projections extending laterally from the peripheral edge for engaging the wall about the periphery of the cavity to prevent the wall box from falling through the cavity and holding the peripheral edge of the wall box substantially parallel with the wall.

Preferably each projection is in the form of a lug.

-10 Preferably there are at least three projections, where at least one of the projections extends from a different side of the peripheral edge to the other projections.

Advantageously, there are four projections, where respective pairs of projections -extend in diametrically opposite directions.

I Advantageously, when the peripheral wall is in the shape of a quadrilateral, the projections extend from each comer of the quadrilateral.

Preferably the wall box further includes a plurality of sets of teeth formed on an outside surface of opposite side walls of the wall box for gripping the wall when inserted into the cavity.

Preferably the wall box further includes a detachable cover that can extend over the peripheral wall to inhibit ingress of plaster or render into the wall box, the cover provided with a marker projecting from the cover and of a length to extend beyond Sany plaster or render normally applied to the wall after insertion of the wall box to .1 enable the locating of the wall box. Advantageously the marker is located at the centre of the cover. This enables an electrician or other tradesman to accurately 25 ascertain the boundary of the cover and wall box. -4- Preferably the marker comprises a flexible pin formed integrally with the cover.

Preferably the cover is flexible so that it can be pushed inwardly to facilitate the breaking of plaster or render applied thereto.

preferably the cover is formed integrally with the wall box and is attached thereto by a frangible web of material. Advantageously, the frangible web is perforated to assist in the detachment of the cover from the wall box.

In an alternate embodiment, releasable fastening means is provided for acting between the cover and wall box. The releasable fastening means typically can be in the form of a number of small pins formed onone of the peripheral edge and the cover; and, holes for receiving the pins formed in the other of the wall box and the cover.

i "An embodiment of the present invention will now be described by way of example S. only with reference to the accompanying drawings in which: Figure 1 is a plan view of a wall box in accordance with the present invention; Figure 2 is a end view of the wall box shown in Figure 1; Figure 3 is a side view of the wall box shown in Figures I and 2; Figure 4 is a plan view of a cover for the wall box; Figure 5 is a side view of the cover shown in Figure 4; and Figure 6 is a view of section A A of the covershown in Figure 4.

Referring to Figures 1 3, an electrical wal box 10 adapted for insertion into a Referring to Figures 1- ripheral edge 14elect cavity formed in a wall (not shown) includes a box 12 having peripheral edge T *I14 r l which defines an opening 16 over which a face plate (not shown) can be connected.

Typically, the face plate is a conventional face plate which may hold a switch andlor a power socket. A plurality of coplanar projections in the form of lugs 18 extend laterally from the peripheral edge 14. The lugs 18 engage or abut the wall about the periphery of the cavity into which the wall box 10 is inserted to prevent the wall box from falling through the cavity and also to hold the wall box 10 substantially parallel with the wall.

The box 12 is in the form of a rectangular box with an open top which forms the opening 16. The box 12 includes a bottom wall 20 opposite side walls 22 and 24 and opposite front and back walls 26 and 28.

There are, in this embodiment, four lugs 18 each one extending from the corners of the peripheral wall 14. The lugs 18 nearest back wall 28 extend in diametrically opposite directions and perpendicular to respective adjacent side walls 22 and 24.

Similarly, the lugs 18 nearest the front wall 26 extend in diametrically opposite 15 directions and perpendicular to respective adjacent side walls 22 and 24.

Six sets of teeth are formed on the outside surfaces of side walls 22, 24. Two sets of teeth 30 are formed on side wall 22, one set being coplanar with front wall 26 and the other set being coplanar with back wall 28. Two sets of teeth 30 are also formed on side wall 24, one set extending coplanar with front wall 26 and the other set extending coplanar with back wall 28. Each set of teeth 30 comprises three separate teeth which are in the general shape of triangular serrations similar to those found on cutting saws. Another set of teeth 32 is provided on each of side walls 22 and 24.

The sets of teeth 32 are formed intermediate the length of respective side walls 22, 24 and, in this embodiment, comprise four teeth each. The purpose of the set of teeth 30 and 32 is to grip the surface of the wall about the cavity in which the wall box 10 is inserted.

The walls 20, 22, 24, 26 and 28 are provided with knock out circular plugs 34 that are formed integrally with the wall box 10. Selected ones of the plugs 34 are k.

-6knocked out to allow for the routing of conduit and electrical cable into the wall box t0.

Four upstanding pins 36 are provided on the peripheral edge 14 for releasably engaging detachable cover 38 (shown in Figures 4 and A separate pin 36 is provided near each corner of the wall box 10 and on portions of the peripheral edge 14 which are coextensive with the front wall 26 and back wall 28. Cover 38 is provided with four holes 40 which are located so as to register with, and receive the pins 36 when the cover 38 is attached to the wall box 10 to cover the opening 16.

.The cover 38 is rectangular in shape and has a planer peripheral lip 42. Each side of I 10 the lip 42 leads to a steeply inwardly and upwardly sloping surface 44 The surfaces 44 in turn lead to surfaces 46 which slope gently upwards and in an inward direction.

Each of the walls 46 leads to a central rectangular planer surface 48. Extending perpendicular from the middle of the surface 48 is a marker in the form of flexible pin 50. The pin 50 is of a height or length so that when the cover 38 is applied to a -15 wall box 10 held within a cavity in the wall, the pin 50 will extend beyond the normal thickness of render and plaster applied to the wall. This facilitates the easy location of the wall box The cover 38 is made from a thin plastics material that can easily depress or collapse when pushed inwardly. This provides a mechanism for easily cracking and breaking any plaster overlying the cover 38 so that the inside of the wall box then can he accessed and a face plate connected.

The face plate (not shown) is connected to the wall box 10 in the conventional manner by use of slide couplings. Slide couplings 52 (which do not form part of the invention) are located in slots 54 formed in each of the front wall 26 and back wall 28. Each slide coupling 52 is provided with a threaded hole 56 which can be Saccessed through a recess 58 formed centrally in portions of the peripheral edge 14 S- which coextend with the front wall 26 and back wall 28- "p -7 The manner of use of the wall box 10 will now be described.

Prior to the installation of wall box 10 a cavity is cut in a brick or masonry wall for receipt of the wall box 10 and one or more channels may also be cut in the wall to receive conduits through which cables are passed for routing into the wall box Depending on the position of the conduits carrying the electrical cables one or more of the plugs 34 would be removed to allow the entry of the conduit and electrical cable into the wall box 10. Wall box 10 is then pushed into the wall cavity to a position where the lugs 18 bear against the outer surface of the wall. The lugs 18 prevent the wall box 10 from falling through the cavity and also ensure that the wall 10 box 10 is parallel or flush with the wall. The cover 38 can then he applied to the wall box 10 and held in place by the engagement of the pins 36 in tile holes 40. A plasterer may then repair or finish off the wall around the wall box 10. In doing so, it is likely that the plasterer will cover the entire cover 38 with plaster and render I save for the pin 15 When an electrician returns to complete the wiring of the house, the wall box 10 is located by simply looking or feeling for the pin 50. Once located, the electrician can simply push in the vicinity of the pin 50 causing the cover 38 to depress or collapse.

This results in the cracking and breaking of the plaster overlying the cover 38. The cover 38 can then be simply pulled of the wall box 10 leaving a relatively clean 20 break or cut of plaster around the edge of its peripheral lip 42. Thereafter, the electrician can complete the wiring and apply the conventional face plate in the normal manner, by use of screws which engage the holes 56 in the slide couplings 52.

The teeth 30 and 32 would typically be embedded in render or filler which is placed |I 25 in a space formed between the outside of side walls 22 and 24 and the size of the ,cavity in which the wall box 10 sits. This assists in holding the wall box 10 firmly in the wall.

~-ru IP-- -P In an alternate embodiment, it is envisaged that the cover 38 is formed integrally with the wall box 10 so that a web or hinge is formed along the part of peripheral edge 14 coextensive with the front wall 26 and a length 42A of the lip 42. The hinge would be formed to normally bias the cover 38 in a closed position to cover the opening 16. Once the wall has been refinished by a plasterer, cover 38 would be removed simply by pivoting it outwardly (after the breaking or cracking of overlying render/plaster) about its hinge and either physically tearing the hinge or using a knife to cut the hinge. To assist in the detachment of the cover 38 from the wall box 10 in this embodiment, the hinge or web can be formed with a line of perforations. In this tO embodiment, at least the pins 36 on the part of peripheral edge 14 coextensive with front wall 26 will not be required. The remaining pins 36 immediately above back wall 28 may optionally be obtained or moved.

From the above description it is apparent that a wall box construction in accordance with embodiments of this invention is unlikely to be lost through a cavity in he wall 15 because of the action of the lugs 18. Similarly, the wall box 10 will be flush or parallel with the wall provided that the lugs 18 bear against the wall. This greatly assists in the fitting of a face plates during the wiring process. Also, the cover 38 assists an electrician in locating the wall box if covered by plaster as well as prevents ingress of plaster and other materials during finishing of the wall.

20 To assist in the use of the wall box 10 with timber frame houses/buildings holes H, are formed in the lug 18 and holes H 2 are formed in opposite side walls 22 and 24.

This enables the wall box 10 to be held in place by mechanical fasteners such as nails, screws or bolts which pass through holes H, and/or H,.

Now that embodiments of the invention have been described in detail it will be apparent to those skilled in the relevant arts that numerous modifications and variations may be made without departing from the basic inventive concepts. For example, the wall box 10 is shown as being essentially rectangular in shape however it can of course be made to any required shape. Further, the number. pocirion and shape of the lugs 18 can be varied from that shown in Figures 1 3. For example, -9rather than having two lugs 18 extending from each of the side walls 22 and 24, the wall box can be provided with a single lug 18 extending from each of walls 22, 24, 26 and 28. Alternately, the box can be provided with three lugs 18 extending from peripheral edge 14 adjacent three of the four walls 22 28. Additionally, the cover 38 may be made of a different configuration to that shown in Figures 4 6 provided that it can be detachably coupled to the wall box 10 preferably is flexible so that it can be depressed or collapsed upon the application of pushing force.

All such modifications and variations are deemed to be within the scope of the present invention the nature of which is to be determined from the foregoing S, 10 description and the appended claims.

Claims (11)

1. 3. A wall box according to claim 2 wherein, there are four projections, where respective pairs of projections extend in diametrically opposite directions.
2. 4. A wall box according to claim 3 wherein, when the peripheral wall is in the shape of a quadrilateral, the projections extend from each corer of the quadrilateral.
3. 5. A wall box according to any one of claims 1-4 wherein, each projection is in the form of a lug.
4. 6. A wall box according to any one of claims 1-5 further including a plurality of sets of teeth formed on an outside surface of opposite side walls of the wall box for gripping the wall when inserted into the cavity.
5. 7. A wall box according to any one of claims 1-6 further including a detachable cover that can extend over the peripheral wall to inhibit ingress of plaster or render into the wall box, the cover provided with a marker projecting from the cover and of a length to extend beyond any plaster or render normally applied to the wall after insertion of the wall box to enable the locating of the wall box. Advantageously the marker is located at the centre of the cover. P- ~Pnon~cT111I-~P- Imwp- ~wn~N_~=cc~o2~~WIZ~ L~3--C- 11 This enables an electrician or other tradesman to accurately ascertain the boundary of the cover and wall box.
6. 8. A wall box according to claim 7 wherein, the marker comprises a flexible pin formed integrally with the cover.
7. 9. A wall box according to claim 7 or 8 wherein, the cover is flexible so that it can be pushed inwardly to facilitate the breaking of plaster or render applied thereto. A wall box according to any one of claims 7-9 wherein, the cover is formed integrally with the wall box and is attached thereto by a frangible web of material.
8. 11. A wall box according to claim 10 wherein, the frangible web is perforated to assist in the detachment of the cover from the wall box.
9. 12. A wall box according to any one of claims 7-9 wherein, releasable fastening I means is provided for acting between the cover and wall box.
10. 13. A wall box according to claim 12 wherein, releasable fastening means Stypically can be in the form of a number of small pins formed on one of the Speripheral edge and the cover; and, holes for receiving the pins formed in the other of the wall box and the cover.
11. 14. An electrical wall box substantially as herein described with reference to and as illustrated by the accompanying drawings. Dated this 27th day of August 1998 CONCEPT 2000 PTY LTD By Its Patent Attorneys GRIFFT HACK Fellows Institute of Patent Attorneys of Australia