US1180397A - Wire-clamp. - Google Patents

Description

D. C. HOOKER.

WIRE CLAMP.

APPLICAHON FILED NOV-29.1915.

Patented Apr. 25, 1916.

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DUNCAN C. HOOKER, OF FARMINGTON, CONNECTICUT, ASSIG-NOR TO THE JOHNS-PRATT COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION OF CONNECTICUT.

WIRE-CLAMP.

Specification of Letters Patent.

Application filed November29, 1915. Serial No. 63,919.

v and useful Improvement in Wire-Clamps,

of which the following is a specification.

This invention relates to those clamps which are provided for connecting branch circuit wires with main circuit wires where the amount of current to be tapped is relatively small and soldered joints are not necessary. These clamps are chiefly used in connection with cut-out blocks, branch blocks, fuse. blocks, meter testing blocks, switch blocks, rosettes. sockets and slmilar electrical devices.

It is common practice to peel a short sectionof the insulationoii from the main wire and apply some form of mechanicalclamp to the bared condu ctor.-- The principal objection to hitherto existing types of clamps has been that if the clamps were madeso' as to properly fita small wire theywere napplicable to a large wire, and woe versa, 1f

the clamps were designed to receive large wiresthey would not properly'clamp small This lack of adaptability has led to wires. considerable trouble, time, and consequent expense to the wireman, as it was necessary for him to hammer and bend the clamps in order to adapt them to a larger wirethan that for which they were designed, or to fill inthe interstices with sheet metal or short bits of wire inorder to adapt them to smaller wires than that for which they were designed. v

The object of the present invention is to produce a simple andcheap clampwhich is so designed that it can be quickly manipulated'by any one in such a mannerthat it will'properly fit any size of wire in a range which practice has shown to be sufiicient to cover all commercial conditions.

Figure I 'ofthe accompanying drawings shows a plan of .a clamp which embodies the invention. Fig. 2 shows a side view of the device arranged to clamp large wires. Fig. 3 shows the same device arranged to clamp wires of intermediate size. Fig. 4 shows a side View of the device arranged to clamp small wires.

The'clamp has a tap strap 1 of any desired length and width. This strap 3 is stamped of sheet brass or other conducting metal with one end bent so as to provide a transversely extending V-shaped recess 2. The

cap plate 3,vformed ofbrassand substan tially the same width as the strap plate,'has

one end flat and its other end stamped so as.

to form a similar transverse \l-shaped recess 4. The, 'V-shaped endof the strap 1 ispreferably somewhat larger than the V- shaped end of the cap 3. Extending through the strap. and cap plates, and preferably threaded into the former, is a screw 5,.which may or may not be provided.with a binding nut 6 having a rounded inner end. The

perforations through the plates for the screw are so located that when the cap is turned one way the V-shaped end of the cap will be opposite the V-shaped end' of the strap, and when the cap is turned around its flatend will be opposite the 'V-shaped end of the strap.

To clamp a wire of large size the plates are put together so that the apexes of the two V-shaped ends will be opposite each other and will project in opposite, directions (as shown. in Fig. 2). When the screw is turned in, or. the nut is tightened, so as to bind the plates together, the wire will be tightly pinched at .four points, thus making strong mechanical and efficient electrical contact. is so small that when the parts are assembled in this waythey fail to make a satisfactory mechanical and electrical engagement with the wire, the cap plate is swung around on the screw so as to'bring its flat end opposite to the V-shaped opening in the strap plate (asshown in Fig. .3) Then when the screw is turned in, or the nut is tightened, the wire will be gripped between two sides of the V- shaped recess in the end of the strap plate andone side of the fiat end of the ca plate. It the wire is too small to be e ciently If the diameter of the main wire clamped in this way the cap plate is removed andturned over so that theapexes of the 'two V-shaped 61'lClS 'Wlll be opposite but will project in the same direction (as shown'in Fig. 4). Then when the screw is turned in,

or the nut is tightened, the small wire will The recesses in the two plates are V- shaped so there will be contact with the wire at three points, when the parts are assembled for clamping a smaller wire (as shown in igs. 3 and at), and at .four points when they are assembled for clamping .a

larger wire (as shown in Fig. 2), and thus insure sufficient mechanical contact to prevent heating. These clamps may be cheaply made in this simple manner in large quantities and used by any wireman for tapping a main wire of any size in common commercial use, according to the conditions which are found at the point to be tapped.

This invention obviates the necessity of providing clamps of Various sizes or requiring the \vireman to bend the ends of the plates if the main wire is larger than the length with the strap plate so-that the cap plate may be turned around and bound to the strap plate with the V-shaped ends opposite each other,'or with the fiat end of the cap plate opposite and closing the opening in the V-shaped end of the strap plate, and

copies of this patent may be. obtained for five cents each, by addressing the thereby provide for clamping Wires of different diameters.

2. A wire clamp consisting of a strap plate having a V-shaped end, a cap plate closes the opening in the V-shaped end of the strap plate.

3. A wire clamp consisting of a sheet metal strap plate having one end bent V- shape, a sheet metal cap plate having one end flat andthe other end bent V-shape, the V-shaped end of the cap plate being smaller than the V-shapedf end of the strap plate, and detachable means holding the plates together so that they may be assembled with the V-shaped ends adjacent to each other and opening in the same direction, or opening in opposite directions, or assembled with the fiat end of the cap plate covering the opening in the V-shaped end of the strap plate, and thereby provide for efficiently clamping wires of widely different diameters.

DUNCAN o. HOOKER.

"Commissioner of Patents.

Washington, D. G."-

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