IL99574A - Wall or ceiling box - Google Patents

Description

m n is τρ> nosij? WALL OR CEILING BOX WALL OR CEILING BOX BACKGROUND OF THE INVENTION This invention relates generally to wall boxes for recessed installation in walls or ceilings to accommodate wire connections or switches, electrical receptacles, antenna or telephone apparatus, and more particularly to wall boxes that have a structure that provides for positive locking or clamping of the the box to the wall or ceiling.

Generally, electrical wall boxes are made of metals or plastics that are approved by the electrical code of the local or national standards authority, and the designs may vary for different, approved modes of construction. For example, a method of affixing a wall box to a brick veneer or wood frame construction usually is, in the case of new construction, the application of the wall box to a wooden stud prior to the application of the plasterboard or lathing and plaster or drywall construction of gypsum board or pressboard or plywood, etc., to form the wall. The affixing is usually performed by nailing or screwing a sidewall of the box to the wooden stud or providing an extension to the box for application to the stud, the extension being provided with projections, usually stamped when made of metal, to act like nails for securing it and its attached box to the stud. For ceiling boxes a shaft of a standard length for straddling and being nailed to a pair of adjacent wooden beams has a box adjustably secured thereto along the shaft.

For old construction, the adding of a wall box, when the stud is not available, often entails the useage of a pair of generally F shaped sheet metal members where the vertical portion extends beyond the upper, horizontal portion of the member such that the vertical portion, when held within the wall with the horizontal portions projecting perpendicular to the wall, prevents the member from being removed from the wall. The length of the vertical portion is longer than the hole containing the wall box. Bending the horizontal members over the adjacent edge of the box into the interior of the box prevents it from being pulled out from the wall.

Another system uses angle brackets secured to the outer surface of the wall and to the box, and relies upon a screw into the wall at a position that is weak, since it is adjacent the edge of the hole. Extra large non-standard cover plates would be required effectively to move the screw away from the edge.

Certain types of wall material are not suited for this mode of attachment.

A system has been proposed utilizing a wall box of plastic having a pair of tapered, narrow, striated members adapted to extend from the body of the wall box from an axially oriented position, perpendicular to the box opening, outwardly to engage the inside wall edge of a hole in a wallboard such that a stria engages the edge to prevent box removal. Because the edge of, for example, gypsum board is weak, this arrangement tends to cause a destruction or crumbling of the gypsum material at the point of contact, thereby producing an undesirable loosening of the box.

Because of the lack of standardization amongst the countries of the world, various shapes for wall/ceiling boxes are in usage.

Quite often the box shape is dictated by the shape of the body of switches, electrical receptacles, etc. A need exists for an universal system to accommodate wall or ceiling boxes for both new construction and renovation of existing structures.

Buildings having cement, brick or cinder block walls generally utilize toothed metal members as part of the switch, receptacle, or other component to be installed, the toothed members being arranged to project and engage the hard surface of the hole, which acts as the box. This type of component should also be utilizable with any box system for the new, modern, thin gypsum board, plywood, etc. walls or ceilings.

A need still exists in order to satisfy current building requirements for an easily manufactured, inexpensive system that does not require labor intensive installation with complicated steps requiring skilled labor.

SUMMARY OF THE INVENTION This invention provides for the utilization of a wall or ceiling box structural arrangement that permits a positive locking of the box in walls of a specified thickness.

Accordingly it is a primary object of this invention to provide a wall or ceiling box that has a positive locking structural arrangement.

It is another object of this invention to provide a ceiling or wall box that is easy to install without skilled labor.

It is still another object of this invention to provide a ceiling or wall box design of any material capable of containaing any sparking that may occur wich is approved by building codes.

It is a further object of this invention to provide a wall/ceiling box structure that allows for the use of components having toothed locking members as an aid in obtaining a positive locking arrangement for the box to the wall/ceiling. a ceiling or wall box that does not require a stepped hole for locking the box in the box aperture or rely on edge engagement of the locking structure.

Still another object of this invention involves the provision of a wall or ceiling box for use with a preformed building sheet of predetermined thickness having an opemng of a predetermined shape and size, comprising, a box forming an enclosure open at one end and having a bottom at an opposite end with a wall forming a body portion between the ends of said box, said body portion being of said predetermined shape and of a size to fit within the opening, a flange proximate to the open end of said box body for engagement with a building sheet to prevent movement of said box through the opening of the building sheet, and a pair of cantilever beams, each having a latching surface as a part thereof facing and generally parallel with said flange and spaced therefrom by a distance substantially equal to the thickness of the building sheet, said cantilever beams being formed of said wall forming said body portion by slotting said wall such that each beam has a movable free end remote from an end attached to and a part of said wall, the ends of said slotting at the attached end of said beam being in alignment along a line substantially normal to said flange.

An additional object of this invention to produce a wall or ceiling box that is easy and economical to produce of conventional, currently available materials that lend themselves to standard mass production manufacturing techniques.

The invention will now be described in connection with certain preferred embodiments by way of example with reference to the following illustrative figures in order to understand the inventive concept.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURES 1 and 3 are horizontal projections of the box of this invention; and FIGURES 2, 4 and 5 are profile projections of the box of this invention with the latch mechanism in its locking position.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the Figures wherein like numerals denote like parts, there is shown a cylindrical wall or ceiling box 10. The box may be of almost any cross section that could be acceptable in accord with standards for electrical apparatus, such as switches, receptacles or the like. Also the material may be any of those approved by the designated standards authority. For convenience in illustrating the invention, a fireproof plastic material such as NURIL, suited for injection molding, is chosen to provide a very economical, fireproof structure having elastomeric and other properties suited to wall or ceiling boxes, as will become apparent from the following description.

A relatively narrow flange 12 is joined to the hollow cylindrical wall or body portion 14 for its insertion into a wall or ceiling recess of like cross section. The cylindrical body 14 has a bottom portion 16 such that the resultant structure 10 forms a cup shaped box with a lip or flange 12. Depending upon the apparatus to be contained in the box 10, a pair of diametrically opposed bosses 18 have holes that are internally threaded at 20 to receive correspondingly threaded screws (not shown) that may be provided for securing the apparatus, for example, a switch or electric receptacle. Alternatively, the bosses 18 need not be threaded if self tapping screws are provided. Any shaped conventional knockout opening with slots or grooves for easy removal, as illustrated at 22 in the various figures, for enabling the introduction of wiring to the interior of box 10 or for providing a mounting place for apparatus may be utilized.

One form of a locking mechanism for box 10, for example, for use with a wall of 12.5 mm. or other standard thickness of plywood or gypsum board, etc., involves the provision of a tongue or cantilever beam 24 whose normal position would be in alignment with the cylinder body 14, since it is formed integral with the body 14 as shown in Figure 2. The natural resiliency of the tongue 24 to axial and radial forces, as it tries to assume its position as part of the body 14, is utilized. For ease of explanation one of the latch members 26, shown in Figure 1, is held within the cylindrical body 14, its position for insertion of box 10 into its recess in the gypsum board, while the other, diametrically opposed, latch member 26 is in its locking position. Figure 3 shows both latch members 26 in locking position.

Each cantilever beam 24 has on its outer surface, as an integral part thereof, a latch member 26 with a wall or ceiling engaging surface 28 for engagement with the inner surface of the wall or ceiling. The outer wall or ceiling surface is in engagement with the flange 12 and the wall or ceiling is thereby clamped between the flange 12 and surface 28 of latch member 26.

The end 30 of the latch member 26 may extend to be in contact with the surface 33 of the clearance slot 32 of the tongue 24 to act as a lock for the latch member within the box, while the box is being inserted in the wall or ceiling recess. Overcoming the frictional resistance would enable the movement of the latch member into its wall or ceiling interior surface engaging position. Alternatively, a piece of cardboard or celluloid (not shown) could be provided, if deemed desirable, to keep the latch arrangement within the box 10 for its easy insertion into a recess in the wall or ceiling. The latch member 26 could have an area at its end 30 of a dimension to the underside of the flange 12 slightly less than the thickness of the wall or ceiling in order to obtain a tight locking fit of the box 10 with the recess in which it is applied.

The remainder of surface 28 could be parallel with the inner wall/ceiling surface, or the entire latch member surface 28 could be slightly out of parallelism with the flange 12 in order to achieve substantially the same effect.

Strengthening supports 34 may be provided to produce additional rigidity to the latch member 26 for its cantilever mounting to cantilever beam 24. Further aspects of the design will become more apparent in the following explanation of the operation for installation of the box 10 in its environment.

OPERATION For the purpose of explanation only, it is assumed that a 12.5 mm. gypsum board wall has had a round hole of appropriate size and shape to match an electrical box 10 with a clearance sufficient for easy insertion of the box, the flange 12 width being sufficient to provide engagement with the gypsum board. Templates are usually used for size and shape conformation.

After removing any required knockout plugs 22 and installing required hardware, the diametrically opposed, curved cantilever beams 24 with their latch members 26 are pressed inwardly and held in position, usually by the engagement of the latch member end 30 with the edge of the clearance slot 32 at the free end of the curved (for a cylindrical box) cantilever beam. It should be noted that the tongue or cantilever beam 24 bends inwardly and outwardly along an axial line on the periphery of body 14 at its joinder with the cylindrical body, for example, along a line through stress relief enlargements 36 of slot 32 as shown in Figure 4. If the box material has elastomeric properties, a force opposed to the inward latching of latch member end 30 with slot edge 32 is exerted to align the tongue 24 toward its position of alignment with the body 14.

The box 10 is then inserted in the prepared hole or recess with the underside of flange 12 in engagement with the outer surface of the gypsum board. The release of latch members 26 for engagement with the interior surface of the gypsum board is effected by applying pressure to the interior, free end of cantilever beam 24 until it is in alignment with the cylindrical body 14. The surface 28 of latch member 26 is forced to engage the inner surface of the gypsum board wall with greater pressure at the end of the latch member attached to the free end of cantilever beam 24, since in this area the distance to the underside of flange 12 can be slightly less than the thickness of the gypsum board, thus locking the box in place. Elastomeric properties of the tongue and body material provides an axial force of the latch member against the gypsum board, when in the locked position. When electrical components having extensible toothed members are utilized, they may be extended to engage the interior, free end of tongue 24 to further lock the attached latch member 26 against inward movement. The elastomeric forces in the locked position now oppose movement of the tongue 24 from its aligned position with the body 14. The free edge, opposite to its joinder with tongue 24, of the latching surface 28 could have a slight bevel, if desired, to avoid damage to the edge of the hole or recess which the surface 28 might engage. The surface 28 could then be in engagement with the gypsum board along a substantial length of the latch member 26 in order to engage an area of the inner gypsum board wall. The generally parallel arrangement of the tongue or cantilever beam 24 with the flange 12 allows for the greater supported length of the surface 28.

Removal of the box 10 may be effected by many modes, one of which is to provide a hole (not shown) in the cantilever beam 24 near its free extremity for insertion of a small screwdriver or a screw for pulling the latch member out of engagement with the gypsum board. Of course, the tongue 24 could be also liberate (for example with a screwdriver) at slot 32 to desengage it from Although the invention has been described with reference to a particular embodiment, it will be understood to those skilled in the art that the invention is capable of a variety of alternative embodiments within the spirit and scope of the appended claims.

Claims (10)

WHAT IS CLAIMED IS:

1. A wall or ceiling box for use with a preformed building sheet of predetermined thickness having an opening of a predetermined shape and size, comprising, a box forming an enclosure open at one end and having a bottom at an opposite end with a wall forming a body portion between the ends of said box, said body portion being of said predetermined shape and of a size to fit within the opening, a flange proximate to the open end of said box body for engagement with a building sheet to prevent movement of said box through the opening of the building sheet, and a pair of cantilever beams, each having a latching surface as a part thereof facing and generally parallel with said flange and spaced therefrom by a distance substantially equal to the thickness of the building sheet, said cantilever beams being formed of said wall forming said body portion by slotting said wall such that each beam has a movable free end remote from an end attached to and a part of said wall, the ends of said slotting at the attached end of said beam being in alignment along a line substantially normal to said flange.

2. A wall or ceiling box as defined in claim 1 wherein said box is generally cylindrical.

3. A wall or ceiling box as defined in claim 1 wherein said box is removable by movement of said beams with latching surfaces from their latching positions in contact with said building sheet to an insertion and withdrawal position within said enclosure.

4. A wall or ceiling box as defined in claim 1 wherein said flange is placed a distance from said open end of said box by a dimension equal to the thickness of a coating to be applied on the building sheet.

5. A wall or ceiling box as defined in claim 1 wherein each of said latching surfaces is integral with said beam and slightly out of parallelism to provide a reduced dimension to said flange at the free end of said beam.

6. A wall or ceiling box as defined in claim 1 wherein each said surface is beveled at the edge first to engage said building sheet to avoid damage thereto and has a reduced dimension to the flange at the free end of the beam to produce a tight fit with a building sheet.

7. A wall or ceiling box as defined in claim 1 including a removable portion of said box for access to the interior of said box.

8. A wall or ceiling box as defined in claim 1 wherein the material of said box has elastomeric properties tending to bias the beams toward their locking position in alignment with said body when they are moved therefrom.

9. A wall or ceiling box as defined in claim 1 wherein said surface is a part of a latch member which is formed to cooperate at the free end of said beam with an edge of said body, formed by slotting, to latch releasably its beam such that said surface is within said box.

10. A ceiling or wall box substantially as hereinbefore described with reference to the accompanying drawings. FOR THE APPLICANT atent ttorney