US935097A - Outlet-box for electric fixtures. - Google Patents

Description

O. F. ERIGKSON & R. H. BRADSHAW.

OUTLET BOX FOR ELEGTRIC FIXTURES.

APPLICATION FILED JUNE 11, 1908.

Patented Sept.28,1909.

WITNESSES:

UNITED STATES ATE FICE.

OSCAR F. ERICKSON, OF BERKELEY, AND RICHARD H. BRADSHAW, OF OAKLAND,

CALIFORNIA.

OUTLET-BOX FOR ELECTRIC FIXTURES- To all whom it may concern:

Be it known that we, OSCAR F. ERICKSON and RICHARD H. BRADSHAW, citizens of the United States, residing, respectively, at Berkeley, in the count-y of Alameda, and Oakland, in the county of Alameda, and State of California, have invented new and useful Improvements in Outlet-Boxes for Electric Fixtures, of which the following is a specification.

The present invention relates to an improved electric outlet box. Heretofore it has been a common practice to secure fixtures for electric lights direct to the lath and plaster in buildings. The objection to this construction is that, by continuous use, the screws which secure the crowfoot or other fixture to the lat-h and plaster become loose, and the plaster also works out or breaks off, the fixture then having to be repaired.

The object of the present invention is to provide a construction which will obviate this objection, so that the fixture will remain firmly and rigidly in place for an indefinite period without further attention.

In the accompanying drawing, Figure 1 is a broken front view of our improved outlet box; Fig. 2 is a vertical sectional view of the same, showing a crowfoot secured thereon; Fig. 3 is a front view of a face plate; Fig. 4 is a view similar to Fig. 2 showing a face plate and socket supported on the outlet box; Fig. 5 is a front view of a special form of crowfoot used with our invention.

Referring to the drawing, 1 indicates a base, adapted to be secured by screws 2 through three countersunk screw holes to the joist 3 or other rough work of the building, so as to lie flat against said joist. Said base is formed in the center with an elongated aperture 4, through which can pass the electric conducting wires and their insulation. At right angles to the slot l said base is formed with depressed or recessed portions 5, the material within which is connected with the main part of the base by comparatively thin connections, so that either of said depressed portions may be easily knocked out by the blow of a hammer, leaving one, or two, lateral enlargements of the slot 4, when it is desired to pass three, or four, electric wires, with their insulation, through the center of said base, instead of two only, this being done when it is desired to take ofi two or more branch circuits instead of Specification of Letters Patent.

Application'filed June 11, 1908.

Patented Sept. 28, 1909.

Serial No. 437,962.

one. Inany case the slot is of such limited 1 size that the electric wires with their insulations completely fill the slot, thus reduc ing the danger of combustion arising from imperfect electric connections within the box. Said base is formed with a circular wall 6, and, formed upon said base within said wall, and intermediate between the three countersunk holes, are bosses 7 rising not quite as high as the top of the wall. These bosses are provided, so that by means of deep screw holes 8 therein, there may be firmly secured in place a crowfoot 9, which, in general, is similar to those already in use, having a central apertured portion 10 adapted to register with the aperture 4 in the base, and having also feet 11, each foot being formed with a countersunk hole 12 to receive the head of a screw by which the foot is secured to one of said bosses.

The outlet box is secured upon the joist or other rough work, before applying the lath and plaster, and is of such depth, that, when they are applied, the plaster is substantially flush with the upper edge of the wall 6 of the outlet box. A crowfoot, such as is at present used for this class of work, may then be secured to the outlet box, by screwing the same thereupon in precisely the same manner as it has heretofore been screwed to the lath and plaster itself. In other words, the box is so constructed and secured upon the rough work, that any standard crowfoot can be a form of crowfoot, which may be secured more rapidly and easily than the ordinary crowfoot, each foot thereof being formed with a transverse passage 13, connecting a side of the foot with the countersunk screw hole 12 therein, these passages being all formed on the same side of the feet, preferably on the right hand side. Thereby the time required for securing the crowfoot in position is greatly reduced, for, the screws being already partly screwed into their screw holes in the bosses, it is only necessary to place the crowfoot slightly to the left, angularly, of its proper position, and then give the same a slight turn to the right, and then the shanks of the screws will pass into the passages 13 in the feet, so that the heads of said screws will be immediately over the counter-sunk holes 12, and then, on screwing down the screws, the crowfoot is secured in secured upon the box instead of upon the lath and plaster. However, we prefer to use place. This can be done in less than onehalf the time required to screw'the screws through their entire length. The fixture is then secured to the crowfoot in the usual manner.

In cases where it is desired to use snap switches, and other fixtures not requiring a crowfoot we provide a special form of face plate 15, formed with countersunk sockets 16 for screw heads, which sockets are in the proper relative positions, so that screws passed through said sockets can be screwed into the screw holes in the box in precisely the same manner as the crowfoot is secured thereto. Said face plate 15 is also formed with the wire holes 17 and with the screw holes 18, so that it can be secured to any standard socket, switch, or rosette. By giving the face plate the same finish as the fixtures themselves, its use improves the general appearance of the fixture.

An important feature of this invention is that the back and wall of the base are formed in a single piece having no opening, either in the back or in the wall, except those for the screws 2 and for the wires and their insulation, thus providing an entirely metallic casing completely surrounding all the joints connecting the fixture to the line, whereby the danger of combustion being started by defective connections is reduced to a minimum.

We claim:

In combination with a backing for. lath and plaster, and lath and plaster secured thereon, an outlet box having a base and a cylindrical wall formed integral therewith,

said base being secured upon the front wall of said backing and the cylindrical wall having its front edgesubstantially flush with the surface of the plaster, said base having a central aperture, and the backing having an aperture registering with the central aper- OSOAR F. ERICKSON. RICHARD H. BRADSHAW.

Witnesses:

WV. P. WOOLSEY, FRANCIS M. WRIGHT.

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