US1735331A - Outlet box - Google Patents

Description

Nov. 12, 1929. J, J. MERRILL OUTLET BOX Filed Aug.- 18. 1921 3 Sheets-Sheet 1 Nov. 12, 1929. MERRILL 1,735,331

OUTLET BOX Filed Aug. 18. 1921 5 Sheets-Sheet 2 Nov. 12, 1929. J, MERRILL OUTLET BOX Filed Aug; 18, 1921 3 Sheets-Sheet 3 Patented Nov. 12, 1929 UNITED STATES PATENT OFFICE JOHN J. MERRILL, 0F IPSWICH, MASSACHUSETTS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO ELECTRIC OUTLET COMPANY, INC, OF NEW YORK, N. 'Y., A CORPORATION 01' NEW YORK OUTLET IBOX Application filed August 18, 1921.

This invention relates to outlet boxes or similar devices for supporting electric fixtures or switches on a lath and plaster wall or ceiling, which has already been erected.

Prior to my invention the supporting means which have been employed for lath and plaster walls, or ceilings, in practice, have not, so far as I am aware, been satisfactory, principally, for the reason that the plaster surface provides an insecure support for a metal base plate or the like, as the plaster is liable to crumble, and laths aflord an unplastering which it engages, or to cause damage to the plaster adjacent thereto.

I accomplish this object by providing a form of box or casing which is adapted to be inserted into an opening between alternate laths formed by removing a section of the intervening lath, and to be held-in position by clamping the lath and plaster wall between clamping members thereon, said members extending over suflicient area to avoid danger of injury to the plaster.

For a more complete understanding of my invention reference is made to the accompanying drawing in which:

Fig. 1 is a sectional View. at the line 1-1 of Fig. 2, of a preferred embodiment of my invention. in position in a wall.

Fig. 2 is a plan view thereof from the back side of the wall.

Fig. 3 is a similar view from the front side of the wall, or from within the room.

Serial No. 498,274.

Fig. 4 is a transverse section, at line 44 of Fig. 2.

Fig. 5 is a detail perspective view of the wlire clamping means which I preferably emp oy.

Fig. 6 is a detail sectional view of the fixture supporting nipple.

Fig. 7 is an elevation illustrating the manner of placing the casing in position in a wall.

Fig. 8 is a sectional view at line 88 of Fig. 9 illustrating a slightly modified form of the invention.

Fig. 9 is a plan view from the inner side of a lath and plaster ceiling.

Fig. 10 is a detail view of the bridge plate which I employ under certain conditions.

Fig. 11 is a detail view of a metal covered conductor clamp.

According to my invention, I provide a box or casing of sheet metal of approximately square form, comprising the end walls, a, a, and side walls I), b, and a bottom 0 which is connected thereto by interlocking the edges or by other suitable means. The end walls a are extended beyond the side walls I) at the bottom side, and the edges thereof are curved or bevelled from the inner edges of the sidewalls to the middle portion thereof, the bottom, which is attached to said edges, being similarly shaped so that the portion of the casing beyond the inner edges of the sides Z), 6 has bevelled or curved sides and flat ends. The end portions of the strip of material, of which the bottom 0 is formed, are extended outward at right angles or perpendicularly to the side walls, 6, to form flanges 01, said flanges extending throughout the length of the side walls and having rounded corners.

A clamping plate 6 is provided having a square or rectangular aperture therein, which is adapted to receive the walls a, a and b, b of the casing, so that it may slide freely thereon, and aligning apertures are provided in said plate and in the flanges d, to receive clampin screws f, the apertures in the flanges being screw threaded therefor.

In the formation of the casing sides and bottom, circular portions are struck out, and practically severed from the adjacent metal, without actually removing said portions, so that they may be easily pushed out from within the casing, to form apertures thru which the heavily insulated conductors, which are located between the inner and outer walls,

may be passed into the casing, where they will be connected to the fixture wires. In order that the conductors may be drawn into the casing at any convenient point, a pair of circular, severed portions 0 are provided in each side portion of the curved or bevelled bottom a and a similar pair of circular portions (1., are formed in each of the end walls a, in the rear of the flanges d and closely adjacent the plane thereof.

A clamping frame g, for the wires, after they are inserted, is provided within casing, said frame being of the same rectangular form as the sides of the casing and adapted to be adjusted to and from the bottom thereof. Arms h, having inwardly bent portions, are extended from the inner sides of the frame, and screws 2' are passed thru said end portions and threaded in the bottom of the casing, to hold said frame in clamping position.

The middle portion of the bottom 0 is provided with an aperture in which a nipple j is inserted, said nipple being externally screw threaded and having a flange j at one end, which is clamped against the back or outer side of the bottom by a nut is, which is screwed on to the nipple against the inner side of the bottom. To hold the nipple from turning, when the nut k is tightened, a lug j is provided on the flange j, which engages in an aperture 0 formed in the bottom 0, as shown in Fig. 6 The bottom 0 has its middle portion flattened and inwardly dished or bevelled about the nipple receiving aperture therein, and the surface of the flange j which engages the bottom is slightly rounded and bevelled, so that the angular position in which the nipple is clamped in the aperture of the bottom may be somewhat varied.

As previously stated, the above described device is primarily designed for installation in a lath and plaster wall or ceiling, already constructed, as distinguished from an installation in a building in process of construction, and, in practice, is so formed that the distance between the exterior surfaces of the side walls I; are approximately equal to the width of an ordinary lath, plus twice the width of the space between two laths. When the casing is installed, a section of one lath, as w, is sawed therefrom, which is equal in length to the distance between the end walls a, and which, in practice, is preferably the same as the distance between the side walls I), so that, when the plaster is removed,

a square hole is formed in the wall or cening, which is bounded by the severed ends of the lath w, from which the piece has been removed, and the edges of the two adjacent laths y and z. I

When the casing is to be inserted in the hole thus formed, the screws f and plate e are entirely removed, and the casing is held by the nipple j in such a position that one of the flanges d is first inserted. Then the casing is moved inwardly and swung laterally towards one side of the hole until the other flange is carried in past the opposite side of the hole, and then the casing is swung so that its sides are perpendicular to the laths, and drawn outward, so that the square portion of the casing is inserted in the hole and the flanges d engage the inner sides of the adjacent laths y' and 2, as indicated in Fig. 7. As the casing should be made as deep as conditions permit, the beveled or approximately cylindrical construction of the bottom of the casing is important, as it enables the casing to be placed in position in the wall from within the room of the building, notwithstanding the narrow space which is usually provided between the inner and outer wall thereof,

and, at the same time, the necessary depth from the wall surface, is secured. When the casing is in position in the wall, its sides a and b will extend slightly beyond the surface of the plaster, under normal conditions. The plate 6 is then placed in position on the protruding ends of said walls, which holds it in predetermined relation thereto, and, by using the holes in the plate as a guide, holes may be drilled thru the laths y and a, which will register with the screw threaded holes in the flanges d. The screws f are then passed thru the plate e and the laths and screwed into the flanges, so as to clamp the intervening laths and plaster between the plate and flanges, as shown in Fig. 1.

Before the casing is placed in position, apertures, as 0"in Fig. 2, are formed by pushing out the partly severed portions a or c, at the points where it is desired to have the conductors enter the casing. If the conductors are to be passed thru apertures in one side of the bottom, then the conductors may be drawn thru the wall opening and then passed thru the casing apertures, before the casing may be inserted while the conductors are in the apertures, otherwise, the conductors usually must be fished thru the apertures after the casing is in position. To do this is usually not especially difficult if the conductors may be easily bent, but it is very diflicult to do this, in many instances when a metal encased conductor is employed.

When the installation is on a wall, the conductors almost invariably run vertically, or at right angles to the laths, so that they may be conveniently drawn thru the bottom open ings, either at one or both sides, under the i ever, the conductors, in most instances run parallel to the floor timbers, and in 9. rec- 'tion parallel to .the-laths, so that, if the box or 'casing is installed in the relative position to the laths shown in Figs. 1 and 2, unless the conductors can'be sharply bent they must be fished thru the openings in the end .walls a. The metal covered conductors usually employed cannot be bent sufliciently to permit insertion thru the bottom apertures, and it isve diflicult to fish them thru .apertures in t e end walls a.

To obviate this difliculty, and to provide means whereby the box may always be set in a position in which the conductors may be drawn thru the bottomo ings corresponding to the apertures c I provide means whereby the box ma be set in a position 90 from that shown in i 1 and 2, said means being illustrated in Figs. 8 to 10, and consisting of a metal bridge plate m of oblong form aving a centrally located aperture, of approximately the same size and shapes as that in the clamping plate e, and having the corners of its end portions rounded and adapted to extend approximately from the middle of one lath to the middle of the lath next but one adjacent thereto, when placed in transverse osition thereon.

The width 0 metal between the side edges of plate m and the edges of the aperture therein is less than the distance from the holes for the screws 7, in the flanges d, to the point where the flanges meet the bottom 0 of the box. A down-turned lip '12. is formed on the plate, at each side of the a erture, of somewhat less width than the thickness of a lath.

When it is desired to set the box at right angles to the position shown in Fig. 2, the plate m is passed up thru the ceiling opening in a diagonal position, the length of the diagonal of the o ening and the width of the plate being ma e to correspond and then the plate is placed in transverse relation on the laths so that its end portions rest on the uncut laths and its side portions on the end portions of the lath which has been cut, and so that the flanges 11. extend down into the ceiling opening. The conductors will then be drawn down thru the opening and passed thru the apertures in one side of the bottom of the box and then the latter will be passed up thru the ceiling opening and the opening of the plate m in such a position that, when the box is swung down into the position in which itis to be held, its flanges will rest on the side portions of the plate, as shown in Figs. 8 and 9. The plate e will then be clamped in position, as before described, the screws 7 passing thru the end portions of the cut lath, past the edges of the late m and into the flanges, as already descri ed, ex-

ceptthatthe screws f pass thru the cut lath instead of thru the uncut laths.

Under these conditions the flanges do not directly engage the laths, but indirectly enage all of them which are adjacent the open- '1ng thru the plate m and, as the latter is clamped firmly against the laths, and the flanges against the late, the box is as firmly connected to the ce1ling as if it were in the opposite position. The plate m also serves to protect the laster as the conductors are drawn thru t e opening.

It will be apparent that, by employing theplate m, when necessary, the box may always be set so that the conductors may be passed into it .thru the o enings in the bevelled or rounded portion 0? the bottom, under all conditions.

When conductors are employed which are not metal covered and are passed thru either the bottom or end openings, they may be clamped in position by clamping the frame 9 against them by means of screws 2', as indicated in Fig. 5. If, however, metal covered conductors are employed and the wiring regulations require that the coverings be grounded, it is necessary to provide an elec trical connection between the covering and the box which is better than would be afforded by the frame g. As when the plate m is provided, it is only necessary to provide openings thru the opposite portions of the bottom a. This permits a form of clamp to be employed for mechanically and electrically connecting the conductor to the box. which would take up too much room therein, if arranged at all sides thereof, but which may be employed on opposite sides only.

For this class of work a slightly modified form of box or casing is employed which is shown in Figs. 8 and 9, and principally differs from that already described in that the bottom 0 is flattened at the portions thereof which are apertured, or cutawa to enable apertures to be readily formed, while no provision whatever is made for apertures corresponding to the apertures a in the end walls, a Under these conditions, ring clamps 0 are preferably attached to the end walls, a in register with the bottom apertures, as shown in Figs. 8 and 11, so that, when the conductors, are inserted, they will be passed thru the clamps 0, which will be tightened about the conductors when they have been pulled into position.

After the box has been secured in position, the nipple j may be set in a perpendicular position and then firmly clamped before the fixture is attached, even though the casing may be held in a somewhat tilted position. The fixture will be attached to the nipple in a well known manner, as indicated in dotted lines in Fig. 1, and, after the connections have been made, the whole fixture support will be concealed by a suitable canopy or shield. When a switch is installed in the casing the nipple will not be employed.

The casing sides and bottom are adapted to be stamped out of sheet metal and the whole casing may be manufactured at small expense.

It will be noted that the above described device possesses various practical features of advantage. The casing flanges are firmly clamped either directly or indirectly against the back surfaces of the laths, so that forces tending to swing the fixture will be effectively resisted thereby, and, as the clamping plate extends over a considerable area of the surface of the plaster, crumbling of the plaster, or other injury thereto, is unlikely to occur. The security with which the casing is attached to the wall is not dependent on the engagement of screws or nails directly with the laths and the lath, which is necessarily cut, or weakened, to enable the conductors to be passed thru the wall, is not relied on at all to support the box, whether the bridge plate m is employed or not. It is to be further noted that a metal wall is rovided between all the adjacent wood wor of the building and the connections within the casing or canopy.

While the device is primarily and especially designed for use in connection with a lath and plaster wall or ceiling, it may also be used to advantage in connection with an inner wall which is constructed of wall board.

From the description given it should be evident that the improved box proper rests wholly behind the wall when in place and has integral flanges formed therewith which bear against the wall and so carry the load of the fixture. The fixture supporting means, as will appear hereinafter, is integral with this portion of the box so that the load on the fixture supporting means is transmitted directly to the integral flanges. The clamping plate serves to hold all of the parts in fixed relation to the wall.

While I have shown and described the embodiment of my invention as used for supporting an electric light fixture, it may also be used to advantage for supporting an electric switch, and it will be understood that the word fixture in the specification and claims, where the context permits applies equally to an electric light fixture and to an electric switch.

- Iclaim:

An outlet box having end walls, side walls secured to the end walls and of a lesser height than the latter, whereby the end walls project beyond the side walls, a bottom wall secured to the projecting portions of the end walls and abutting the lower edges of the side walls, flanges formed on the ends of the bottom wall and projecting at right angles to the side walls from the points at which the walls

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