US802999A - Fuse-block or cut-out. - Google Patents

Description

2 SHEETS-SHEET 1.

PATENTED OCT. 3l, 1905.

H. W. LAWRENCE. FUSE BLOCK 0R. GUT-OUT.

APrLIoATxoN FILED APR. so, 1904.

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PATENTED OCT. 3l, 1905.

H. W. LAWRENCE. FUSE BLOCK 0R CUT-OUT.

2. T ...n E H n n S T \C v m E Y E H s na APPLICATION FILED APR.80,1904.

NTTED STATES PATENT oEEioE.

HARRY W. LAWRENCE, OF DENVER, COLORADO, ASSIGNOR TO THE NEW ENGLAND ELECTRIC COMPANY, OF DENVER, COLORADO, A CORPORA- TION OF COLORADO.

FUSE-BLOCK OR CUT-OUT.

Specification of Letters Patent.

Patented Oct. 31, 1905.

T0 @ZZ whom it may concern:

Beitknown that I, HARRY W. LAWRENCE, a citizen of the United States of America, residing in the city and county of Denver, State of Colorado, have invented certain new and useful Improvements in Fuse-Blocks or Cut- Outs; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same', reference being had to the accompanying drawings, and to the figures of reference marked thereon, which form a part of this specilication.

My invention relates to improvements in fuse-blocks or cut-outs employed in the electric wiring of private houses, oflice-buildings, 850.; and the objects of my invention are, iirst, to provide a fuse-block adapted to receive the ordinary inclosed cartridge-fuse and also to completely incase the same and which is so constructed as to facilitate the removal or replacement of the fuse or fuses; second, to provide a fuse-block to which the circuitwires are connected in such a manner that accidental short-circuiting, due to the contact of any conducting material with the uninsulated ends of the live Wires, is positively prevented; third, to provide a fuse-block and cover so constructed that should the cover thereof be left off for any purpose nothing could be laid against or hung across or dropped into the block or accidentally work into the block in such a manner as to shortcircuit the poles or arrange itself parallel with the inclosed fuses, so as to conduct the current independent of the fuse from one terminal to the other; fourth, to provide a fuseblock that is adapted to operatively receive any of the inclosed fuses in usesuch as the knife-blade or screw-clamp or spring-clip inclosed fuses-and, fifth, to provide a fuseblock that is constructed to prevent the spring-clamps that hold the inclosed fuses from being sprung back far enough to prevent their resilient return to operative position. I attain these objects by the mechanism illustrated in the accompanying drawings, in which- Figure 1 is a plan View of my improved fuse or cut-out block supplied with the fuses, clamps, and terminals to which the circuitwires are secured, the cover of the block being removed. Fig. 2 is a longitudinal vertical sectional view on the line 2 2 of Fig. 1, the cover being shown thereon. Fig. 3 is a transverse sectional view on the line 3 3 of Fig. 2. Fig. 4 is a transverse sectional View on the line 4 4 of Fig. 2. Fig. 5 is a central longitudinal vertical sectional View through the block and cover. Fig. 6 is a vertical longitudinal sectional view similar to Fig. 2, but omitting the cover, fuse, and clamp; and Fig. 7 is a perspective view of the block, the cover being shown raised above the block.

Referring tothe drawings, the numeral 1 indicates the block, which is preferably constructed of vitrified porcelain, this material being capable of withstanding a very high degree of heat, and 2 the cover, which is of the same or of other suitable material. The block is provided with two longitudinal chambers 3, Which are closed at each end by walls of suitable thickness and separated by a partition 4, which with the sides of the box form the side walls of the chambers 3. Apertures 5 extend through the end walls of each chamber on a level with the floor of the chambers, and terminals 6 are secured in suitable recesses 7 in the floor of the chambers and at the ends thereof. These terminals are such as are in general use and comprise plates 8 and 9 and fuse-clamps 10. The plates 8 are secured within the recesses 7 by screws 11, which extend up through the bottom of the block, the heads of which lie in recesses 12 in the bottom of the block, which recesses are filled with a suitable cement to prevent the screws coming in Contact with any conducting material. Upon the ends of the plates 8, adjacent to the ends of the chambers, are secured the plates 9 by screws 13, and between these plates, which are slightly recessed for the purpose, are clamped the ends of the circuitwires 14 and 15, as will be seen by reference to Fig. 3. To the opposite ends of the plate 8 are riveted the spring-clamps 10, which hold the ends of the cartridge-fuses 10A, and the terminals in each chamber are in alinement with each other and with the apertures 5 in the ends of the chambers. The width of each chamber is such as to prevent the members of the fuse-clamps from being sprung apart more than is necessary in removing and replacing the fuses, thus obviating the possibility of accidentally springing the clamps IOO beyond the limit of their normal resilient tension, which, if it could be done, would ruin the contact of the clips around the terminals of the cartridge fuse and perhaps cause an arc, which mig'ht ruin the cut-out or at least would permit the fuse to drop out, and thereby break the circuit. These fuses are of the type in general use, and therefore require no description. 1n order that the fuses may be easily and conveniently removed or replaced, I form semicircular recesses 16 in the sides of the block and centrally of the length thereof, which extend from the top of the block to the iioor of the chambers, and a corresponding recess 17 is also formed in the partition 4. These recesses 16 and 17 permit the thumb and forelringer to be passed around the fuse, so that it may be easily grasped and withdrawn. The depth of the chambers 3 is such that when the fuses are clamped in position therein they and the cut-out terminals will be a suijcient distance below the top of the block to prevent their contact with any article that might inadvertently be placed across the face of the block and which otherwise would short-circuit the current. As before stated, the chambers are only a little wider than the width ot' the fuse-clamps in order that the clamps may be sprung apart sufiiciently to insert or withdraw the fuses, and in order to obviate the possibility or' articles, such as screws or nails or pieces of wire, from being accidentally dropped into the block in such a manner as to connect with the two terminals of each fuse, which would shunt a portion ofthe current from the fuse and would prevent the fuse from blowing in case an excess of current should pass over the circuit-wires and also to prevent any possibility of such articles being laid or falling across the terminal ends of the two inclosed fuses, and thus short-circuiting their poles. The side walls of the chambers 3 are formed with projections 18, arranged in oppositely-positioned pairs on each side of the central portion of the fuses or of the linger- recesses 16 and 17. These projections extend from the bottom to the top of the chambers and to within a very slight distance of each fuse, making it practically impossible for anything to drop into the block in such a way as to make a circuit with the terminals of each individual fuse. In clamping the circuit-wires to the terminals the insulating material is first cut away from the end of the wire in such a manner as to form a shoulder which when the wire is clamped will rest squarely against the end of the terminal, as shown in Fig. 2. It will then be seen that the bare portion of the wire or that from which the insulation has been removed is entirely inclosed by the terminal; but if the wire should be clamped in such a way as to leave an uninsulated portion between the end of the terminal and the point where the insulation was cut away to form the shoulder the thickness ot' the wall oi the block through which the wires pass tothe terminal would efectually prevent any article from contacting with the wire or wires from the outside and producing a short circuit.

It will thus be seen `from the construction herein shown that both the wires and terminals are so protected as to render accidental short-circuiting and shunting around the fuses between the terminals practically impossible. The construction and arrangement are also Such as to prevent persons coming in contact with the terminals, which sometimes happens with dangerous results, particularly when the circuitwires have become grounded.

The cover 2 of the block is intended to securely close the chambers 3, and in order to accomplish this the under side ot' the cover is provided with downwardlyprojecting ears 19, which are designed to lit snugly in the linger-recesses 16, formed in the sides of the block, and with a central depending ear or lug 20, which tits into the linger-recess 17 of the partition 4. The lug 2O is provided with a screw-hole 21, which opens into a circular recess 22 in the face of the cover ot' suiiicient depth to entirely inclose the head of a screw 23, by which the'cover is fastened to the block. This screw passes through a hole 24 in the bottom of the block, which opens into a square recess 25, capable of receiving a nut 26, which receives the end of the screw. The partition 4 is provided with circular recesses 27 of considerable depth, and from the bottoms o't' these recesses screw-holes 28 extend through the block. Screws are pressed through these holes into any suitable support to which the block may be secured, and the recesses 27 will entirely inclose the heads ot' the screws.

It sometimes happens that when a fuse is blown the inconvenience occasioned thereby is temporarily remedied by connecting the terminals with a piece of fuse-wire. lith the uncovered blocks which are at present employed such an expedient frequently results in a lire by reason of' sparkingr or a l'lash from the blowing of the fuse-wire, and if the fuse-wire is not carefully secured to the terminals sparking is an almost inevitable result; but with a block constructed as herein shown the temporary use of a fuse-wire could not possibly cause a fire, owing to the secure manner in which the terminals are inclosed, and, while my improved cut-out is designed to prevent the use of the common fuse-wire as far as possible, should, however, it be employed the cut-out is so designed that the danger of ire is reduced to a minimum.

The fuse-block or cut-out herein described is thoroughly practical, and its construction by which the wires and terminals are protected obviates short-eircuiting and the danger of lire from the temporary use of 'fuse-wire.

What I claim as new, and desire to secure by Letters Patent, is*

IOO

ISO

1. In a cut-out, a block having chambers separated by a partition, which has a central recess forming communication between the chambers 3 similar recesses in the outer sides of the chambers, in line with the recess in the partition, and apertures through the ends of the chambers; a cover for said block having depending ears upon its under side, which it into the recesses of the sides and partition of the block, a hole in said cover which extends through the central ear, a corresponding hole through the bottom of the block, forming a continuation of the aforesaid hole, and means for securing said block and cover together.

2. In a cut-out, a block having chambers which are separated by a central partition, said chambers having apertures extending through their ends, a recess in each side of the block communicating with a chamber and a similar recess in the partition communicating with both chambers, said recesses extending'from the top of the block to the bottom of the chambers; oppositely-arranged projections on the sides of the chambers, and adjacent to the recesses, which serve to contract the width of the chambers at that point, and holes through the partition for the passage ofsecuring means.

3. In a cut-out, arblocl having chambers which are separated by a central partition, the sides of said chambers and said partition being formed centrally with recesses which extend from their top edges to the bottoms of the chambers; projections on the sides of said chambers adjacent to the recesses, which serve to contract the width of the chambers at this point; apertures through the ends of the chambers and a cover for said block having projecting ears which iit into the recesses in the sides and partition of the block, and means for securing said cover upon said block; in combination with terminals at the ends of said chambers adjacent to and in alinement with the apertures the fuses connecting said terminals, and the circuit-wires extending through said apertures and secured to said terminals the extreme height of said terminals, being less than the depth of the chambers.

4. In a cut-out, the combination of a block having chambers which are reduced in width for a part of their length at their central portions and recesses in the sides of said chambers extending from the top of the sides to the bottom of the chambers; a thick wall at the ends of said chambers having apertures therein which open into the chambers; terminals in the widened ends of said chambers adjacent to and on a line with the apertures; the fuses connecting the terminals and which lie in the narrow portion of the chambers, the said 'fuses and terminals lying below the plane of the top of the block; the cover having depending ears which fit into the recesses of the block, and means for securing said cover upon said block.

In testimony whereof I aflix my signature in presence of two witnesses.

HARRY IV. LAWRENCE I/Vitnesses G. SARGENT ELLIOTT, CLARENCE R. DEDERICK.

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