US570167A - Edwin t - Google Patents

Description

(No Model.)

E. T. GREENFIELD.

METALLIC JUNCTION BOX AND MEANS FOR UNITING METAL UONDUIT TUBES THERETO.

UNTTED STATES PATENT rrrcn.

EDVIN T. GREENFIELD, OF NEV YORK, N. Y., ASSIGNOR TO THE INTRIOR CONDUIT AND INSULATION COMPANY, OF SAME'PLACE.

METALLIC JUNCTION-BOX AND MEANS FUR UNITING METAL CONDUlT-TUBES THERETO.

SPECIFICATION forming part of Letters Patent No. 570,167, dated October 27, 1896.

Application filed April 6, 1896. Serial No. 586,428. (No model.)

To @ZZ whom, it may concern:

Be it known that I, EDWIN T. GREENFIELD, a citizen of the United States, residing at New York, in the county of New York and State of New York, have made a new and useful lmprovementin Metallic J unction-Boxes and Means for Uniting Metal Conduit Tubes Thereto, of whichthe following is a specilication.

My invention has for its objects, iirst, to increase the efiiciency of junction-boxes of the type named, and, second, to diminish the expense of the structure of such boxes and their attachments.

My invention will be fully understood by referring to the accompanying drawings, in which Figure l represents in plan view the interior of an electrical junction-box provided with my improved means for attaching three radiating conduit-tubes thereto. Fig. 2 is a sectional view of the same, taken on line ma, Fig. l. Fig. 2L is a detail perspective view of one of the split locking-rings for locking the parts together, and Fig. 3 is a longitudinal sectional view illustrating` the application of my improved means of uniting conduit-tubes to j unction-boxes as applied to the joining together of a pair of conduittubes.

Prior to my invention it was old in the art to make metallic j unction-boxes provided with tubular necks adapted to receive interiorly the ends of tubular conduits. It has been customary in the use of such junction-boxes to unite such tubular conduits thereto in various ways, but not, however, with such security as would prevent them from being drawn out of the necks under undue strain. lt is true that such a union might be effected by providing female screwthreads for the inner surfaces of the projecting necks of such boxes and corresponding male screw-threads upon the outer surfaces of the ends of the conduit-tubes; but such methods of union have heretofore been rejected owing to the expense of screw-threading the parts. It was with a view of providing a means of uniting these parts securely together in a cheapA and efficient manner that my present invention was devised, and

I will now proceed to describe the same, referrin g to the drawings in detail. n

I cast junction-boxes B of soft metal in molds, under air-pressure, in a manner well understood by those skilled in metal working, said junction-boxes being provided with any desired number of necks N N N, cast integral with the boxes and screw-threaded on their outer sufaces, the screw-threads be- 6o ing formed, preferably, during the process of casting. These j unction-boxes are then lined with paper H, treated with insulating material, or any preferred insulating-lining may be used and applied in any manner by those skilled in the art.

F F represent lugs which are provided with screw-holes for securing the box to the wall or ceiling.

C represents a detachable cap adapted to 7o be secured to the top of the box by screws s or in any preferred manner.

T T T represent armored conduit-tubes provided with insulating-linings P, the ends of said tubes being adapted to iit snugly Within the inner surfaces of the necks N N N.

R represents a split ring of metal adapted to fit snugly upon the outer surface of the tubes T, said split ring being cone-shaped at one end and adapted to iit in the correspond- 8o ing cone-shaped outer ends of the necks N N N.

D represents a screw-threaded locking-collar which is adapted to iit over the ends of the tubes T so that its inner surface will abut against the base of the split ring R, said locking-collar, with its screw-threads, being cast under pressure in the same manner as was the box B.

E represents a iianged thimble of insulat- 9o ing material adapted to fit in the inner end of the neck N so that its free end extends into the junctionbox slightly beyond the insulating-lining H thereof.

In uniting the parts together the thimbles E are inserted in the manner shown in Fig. 2 into the necks N of the ju notion-box, and the ends of the tubes T are inserted against the anged ends of said thimbles, the lockingcollars D and rings R having first been slipped 1 oo upon said tubes. The locking-collars are then turned through the agency of a pipewrench into locking position, the screwthreads t on the colla-rs i' and the corresponding screw-threads in the locking-collars causing the wedge-shaped rin to vforce the tubes T lirmlyhomc against the llan ges of the thimbles IC. \Vith such an arrangement the wedge action et' the rings R causes the inner ends of the tubes T to be as iirmly united to the junction-boxes as would be possible with screwthreads. In place of the rings R, I might use simple wedges disposed at various peints around the tubes T.

In Fig. 3 I have shown the application of my ilnproved lockingmeans for uniting two armored tubes T T together through the agency of a locking-joint G and the lockingeollars I) D and locking-rings R R, E Ill being insulating gaskets or rings adapted to complete the insulation between the insulating-lining IJ I et' the tubes and the corresponding insulating-lining of the locking joint G.

My claims hereinafter made are designed to cover also the application of this `feature to uniting pipes or tubes together, as well as to the union ot tubes to junctiouboxcs- This invention also has equal utility in connection with concentric systems of conductors in which the outer tube T and the junction-box ll constitute a part et the electrical conducting system.

In the event ot' the use ot' my invention with concentric systems of conductors the outer ends ol.' the tubes T and the inner surlaees ot' the integral necks N should be pretera-bl y electroplated with copper, and the split ring R should be ot' copper or other goed conducting metal. I should prefer also to have the locking-collar D in that eventot' copper, for the purpose oi' increasing the conductivity ot' the system. \\'hen used in connection with concentric systems, the lining II and thimbles E might, il;l preferred, be done away with, the interior or concentric conductor being a \\ellinsulated conductor.

Having thus described my invention, what I claim, and desire to secure by .Letters latent of the United States, is-

l. A junction-box provided with an integral screw-threaded neck, a screw-threz'ided locking-collar and means for lirmly gripping or holding a tube in place in alinement with said neck, said gripping means being adapted to exert a wedgiug action between the neck and the locking-collar, substantially as dcscribed.

2. A junction-box provided with an integral screw-threaded neek,in combi nation wi th a tube adapted to tit snugly within said neck, and a ceneshaped ring for gripping or holding the tube and the neck i'lrmly together, substantially as described.

A j auction-box provided with a series of integral screw-threaded necks, a series el.' tubes adapted to lit each snugly within one oi said necks, and a locking-collar and wedg ing means foreach neck adapted to unite said neck and tube together, substantially as described.

4c. A junction-box provided with one or more eXteriorly-screw-thrcaded necks,in eombination with a screw-threaded locking-collar and a cone-shaped split .ring Vfor grasping or holding' a pipe or tube in alinemcnt with said neck, substantially as described.

5. A metallic junction-box provided with an insulating-lining and a series et' hollow screw-threaded necks, an insulating-thimble for each neck extending within the box, an armored com'luit-tube adapted to lit within each neck, a screw-threaded locking-collar foreach neck, and a locking d evice controlled thereby, all of said parts being so arranged that when the collars are screwed home the parts are rigidly united together, substantially as described.

In testimony whereof I have hereunto subscribed my name this l-th day of; April, 1896.

ICD'WIN T. GREENFIICLD.

Witnesses:

C. J. KINTNEH, W. T. RUETE.

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