US2508655A - Clamping connector - Google Patents

Description

3, 1950 M. M. SILVERMAN CLAMPING CONNECTOR INVENTOR Filed July 25, 1.945

mill/I 41 MONTE M. SlLVERM/AN ATTORNEY Patented May 23, 1950 CLAMPIN G CONNECTOR Monte M. Silverman, Los Angeles, Calif., assignor' to T & M Manufacturing Company, Los Angeles, Calif.,

a firmcomposed of Thomas and J. J. Masterson Michael Application July 23, 1945, Serial No. 606,664

4 Claims. 1

This invention relates to improvements in clamping connectors for electric cabinet boxes such as switch boxes, gutter" boxes and the like.

The objects of the invention are to provide a connector for metal cabinet boxes which is simple 7 in construction; which is easily applied thus making possible a saving in time; which rigidly holds together two or more boxes or affords rigid support for one or more boxes on another; which provides a conduit through which the electric wires may be quickly and'easily passed without injury to the insulation; which provides good electrical connection between the members clamped together thereby affording a good ground circuit. I

These and other objects are attained by my invention, which will be clearly understood from the following description and the accompanying drawing in which:

Fig. 1 is a cross-sectional view showing my clamping connector as used to clamp together the adjoining walls of swtch boxes and the like;

Fig. 2 is an end elevational view of the sleeve member of my device;

Fig. 3 is an end elevation of the assembled clamping connector;

Fig. 4 is an end elevational view of the spacer member of my device;

Fig. 5 is a side elevation of the spacer member;

Fig. 6 is an enlarged fragmentary view of a portion of the spacer member;

Fig. 7 is a cross-sectional view taken on the line l-'l of Fig. 6;

Fig. 8 is an end view of a modification of the sleeve member;

Fig. 9 is an enlarged fragmentary edge view of a tooth of Fig. 8.

In connection with electric wiring practice, it is often desirable to use two or more metal cabinet boxes positioned close together, and to connect these two boxes with each other mechanically by means which will form a conduit through which electrical conductors or wires may pass from one box to the other. It has been common practice to use externally threaded pipe nipples and nuts, or internally threaded bushings to connect two boxes together in this manner. These require not only more expensive parts, but also require much more time to properly install, and the arrangement is mechanically not very rigid, and as ordinarily applied, the electrical connection between the parts is not good enough to provide a satisfactory grounding circuit.

My connector may be made of strong parts, and because of the clamping action, afiords means for 2 rigidly connecting and supporting one box on another, for example a, switch box may be supported on a gutter box, and may be used without further support or attachment. Referring to the drawings, my clamping nector consists of a sleeve I0, a'spacer II and a lock nut l2. As shown in Fig; 1 two partition walls of switch boxes or the like, (represented by broken lines) are engaged, at knock-cu disc holes, between the flange [3 of the" sleeve land the lock nut E2 on the threads IE3 at the-end 0f the'sleeve opposite the flange l3, with the spacer member l i intermediate the partition walls being joined. The electrical wires (not shown) are passed through the cylindrical opening of the sleeve, the sharp edges having been removed to avoid abrasion oi the insulation on the wire.

The sleeve it consists of a cylindrical body having an outside flange i3 with ears M which may be grasped by thefinger or engaged by a suitable tool. The under side. of the flange I3 is relieved or undercut so that the edges of the ears I l make good physical and electrical contact with the metal wall, the ears being purposely sharp edged so that they will scariiy and cut through the paint or lacquer finish on the partition walls. The sleeve Ill is provided at the end opposite the flange with external thread [5, upon which the lock nut l2 may be threadedly engaged, the lock nut l2 also being dished or relieved so that its ears I6 will scarify and cut into the surface of the partition walls being clamped by the device.

The spacer member H is a cylindrical body loosely fitting over the outside of the sleeve l0. adapted to space apart the partition walls of the switch boxes, etc. In order to make good mechanical and electrical contact, the sleeve I0 is provided on both ends with staked scarifying ears I! with extended abutting portion HA (see Figs. 4 to 7) which are sharp edged and adapted to scarify and cut into the finish and metal of the partition walls, to make good electrical contact, and also to prevent loosening of the clamping device by vibration, etc. A plurality of staked ears are formed on each end of the spacer.

As shown in Figs. 8 and 9, the ears it of the flange i3 of the sleeve it may be slightly twisted or canted to form a leading edge I9A which is better adapted to scarify the paint or lacquer finish on the metal walls of the switch boxes, etc., and to form a vibration-proof contact with the surface. The ears of the locking nut may also be slightly canted to give better scarifying action on the metal surface to be clamped.

the bushing by the ears while tightening the nut on the assembly with his other hand, or by means of a suitable tool applied to the nut. In other types of connectors between boxes, it frequently requires two workmen, because one man cannot see to manipulate the necessary tools simultaneously in the two boxes. When the ears of the flange are canted to better scariiy the metal sure face, the application of a tool to the sleeve may not be required.

My device is simple and inexpensive to manufacture and to install. The parts may, of course, be made of any suitable length and diameter to meet. the requirements for standard electrical wiring fixtures. The parts are preferably made of heavy stock so that rigid mechanical connections between boxes may he made I V I-claim: a

'1. A clamping connector. for.- electrical switch boxes and the like consisting or a sleeve having an outwardly extending flange atone end and external threads at the other end, the said flange having spaced peripheral scarifying ears adapted for? hand gripping and said flange having its sur-- face adjacent the ontersur face of the sleeve relieved to permit direct contact of said ears, with a metal wall to be clamped thereagainst; a cy linidrical-sspacer adapted to fit over said sleeve, the endsof said spacer having staked scariiying ears; and a locking nut adapted to screw onto the threads of said sleeve, said locking nut having scarifyingears and havinga relieved surface between its threaded. hole and said ears on the side of said nut adfiacent said spacer.

2. A clamping connector for electrical switch boxes and the like consisting of a sleeve having an outwardly extending flange at one end and external threads at the other end, the said flange having spaced peripheral ears, said ears being canted and adapted to scarify' a'metal wall to be clamped thereagainst; a {cylindrical spacer adapted to fit over said sleeve, the ends of said spacer having staked scarifying ears; and a locknut adapted to screw onto the threads of said sleeve, said locking nut having scarifying ears.

3. A clamping connector ,for electrical switch boxes and the like, consisting of a sleeve having an outwardly extending flange at one end and external threads at the other end, the said flange be n pmtvided with canted peripheral ears; a

cylindrical spacer adapted to flt over said sleeve,

REFERENCES, metric The toilet ns r i ree s are. it e r n. e le. of is; atent UNITED STATES PATENTS;

Number Name Date "756,246 Apr. 5, i904 850,242- Olson Mar. 1 2', 1%32 1,955,106 Von Normann Apr; 1'7; 19-34

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