US1178199A - Electrical fuse. - Google Patents

Description

LE. WOOD.

ELECTRICAL FUSE. Avucmon FILED MAY21, 1913.

1 178, 99. 'Patented Apr. 4, 1916.

UNITED STATES PATENT OFFICE.

JOHN E. WOOD, 0F NEW YORK, N..Y., ASSIGNOR TO METROPOLITAN ELECTRIC MFG.

CO., A CORPORATION OF NEW JERSEY.

ELECTRICAL FUSE.v Y

Specification of Letters Patent.

Patented Apr. 4, 1916.

Application filed May 21, 1913. Serial No. 768,911.

-zen of the United States, residing at the city of NewYork, borough of Brooklyn, and State of New York, have invented cer` tain new. and xuseful Improvements in Electrical Fuses, of which the following is a full, clear, and exact description.

This invention relates to inclosed 'fuses for electric circuits.

The object is to provide primar1ly for making. the terminals and the fuse elements into 'a mechanically distinct and independent unitary structure from the inclosing casing. Such a construction affords many advantages which will be pointed out hereinafter.

The invention consists essentially in connecting the metallic terminalsvof an inclosed fuse mechanically together by means of a stout bar of non-conducting material.

The invention also consists in certain details of construction relating to the casing of the fuse and to means for connecting and disconnecting the fuse element therewith.

In the accompanying drawing; Figure 1 is a plan of the unitary structure comprising the inclosed fuse element; Fig. 2 is a side elevation of the same; Fig. 3 is a view similar to Fig. 1, when associated with the casing; Fig. 4 is an end View of the casing with parts broken away; and Fig. 5 1s a section of one of the end caps of the casing.

The fuse element comprises essentially two terminal plates 1 and 2 connected together by a bar 3 of non-conducting material and the fusible strip 4 through which the current passes from one terminal to the other. The bar 3 is permanently fixed to the two terminal plates 1 and 2 by means of rivets 5 or in any other suitable manner.

The bar is of sufficiently stout material and Y of such a size as to sustain all the strains to which the device will be subjected in handling or use. The fusible strip 4 may be of any approved form and it is secured at its extremities tothe respective terminal plates l and 2 by means of bolts 6 and nuts 7 instead of' by solder as is the usual practice. Since the two terminal plates are permanently secured together by the bar 3 and the bolts 6 are permanently located at a definite distance apart, the fusible strip can be-made of a standard shape and size and be quickly adjusted and connected to the terminals by fuse in the circuit.

means of the bolts and nuts referred to, and by this method of mountingythe fuse, the latter is not liable to injury through lack of support when being assembled and the bolts and nuts furnish perfect contact between the fuse and the plates. This unitary structure is to be inclosed in a suitable caslng which is of the ordinary tubular form indicated in the drawing by 8. This tube surrounds the adjacent ends of the terminal plates and the fuse element and connecting bar, the outer ends of the terminals 1 and 2 projecting through and beyond the ends of the tube to afford means for connecting the Each end of the tube is provided with a metal cap 9 havingl a narrow fiange 10 extending laterally inward and which holds in place a loose metal disk 11, the edges of the same being clamped between the flange 10 and the end of the tube. This disk is provided with a number of perforations 12 to afford ventilation to the in-v terior of the casing andit is also provided with a diametrical slot 13 extending nearly but not quite across it. This slot is of such dimensions as to just'allow one of the terminal plates to pass through it. The flange l() of the cap is provided at opposite points with notches 14.- of such size as to nicely fit the edges of the terminals 1 and 2 and the depth is such, as to permit the terminal when lined up with the two notches, to pass through them. The flange 10 adjacent one side of each notch 11 is deeper than at other places and formed with an eccentric surface 15. This portion being likewise bent'outward or away from vthe disk 11 as shown in Fig. 5. Theterminal plates 1 and 2 are each provided with oppositely disposed notches 16 which are adapted to receive the edge of flange 10 on the cap.

To assemble the unitary fuse structure in the casing, the disk 11 and cap 9 are first applied to one end of the tube 8, then the fuse structure is passed through the opposite end of the tube and the plate 1 is directed through the slot 13 in the disk after which by twisting the unitary structure and rotating the' disk. the plate 1 is brought into alinement with the notches 14 through which then the plate readily passes. The Aplate is slipped through until its notches 16 come into the plane of the flange 10 whereupon the unitary structure is rotated a half turn, which brings the inclined surfaces on the flange against the bottom of the notches 16 and causes a frictional engagement therewith, which prevents the cap and plate from rotating in either direction farther with respect to each other. The other cap and disk are then slipped over the endof the other terminal plate until the notches 16 in the plate are in the plane With the flange 10, when the cap is rotated to bring the eccentric surfaces 15 into the notches 16. At the instant of the engagement by ythe surfaces 15, the faces of these parts of the flange which project outward, engage the ends of notch 16, which causes one cap to be drawn along the tube toward the other and holds all of the parts together by friction.

To disassemble the structure in order to refill the fuse, the unitary structure is simply rotated in the opposite direction through a half turn to bring the notches of one of the terminal plates into line with notches, 14, whereupon the unitary structure can be bodily Withdraivn from the tube. When thus withdrawn, it will be seen that the process of removing the ends of the destroyed fuse and substituting a good fuse ca'n be easily and quickly accomplished, because of the fact that the two terminals are firmly secured together.

The structure as a Whole, has great mechanical strength on account of the reinforcing bar 3 and the strain of handling the device either in applying it to the contacts with which it is to be associated, or in removi g it therefrom is sustained by the unitary structure and not by the tubular casing. For this reason the casing may be of lighter and less expensive material than usual and may be even made of iexible and ireproof material should those qualities be desired. The fuse element can be easily examined or handled at any time Without getting it out -of adjustme'ritor getting the contacts out of alinement and'thus introducing difliculty in replacing the element in the casing.

It is to be understood of course, that the interior of the casing is to be filled as usual with non-conducting material in commi either a refllable or non-refillable inclosedl fuse, but its advantages are best obtained in the refillable type.

Having described my invention, I claim:

1. In an inclosed fuse, a tubular casing open at both ends, flanged caps ttinglexteriorly over the ends of said casing, closing `disks interposed between the flanges of said caps and the ends of said casing, a unitary fuse structure contained in said casing and projecting through slots in said disks, means on said structure and flanges of said caps, respectively, for drawing'the caps toward each other upon relative rotation thereof and for locking said caps in position.v

2. In an inclosed fuse, the combination with a tubular casing, the flanged caps and closing disks, said disks having slots'and the flanges having oppositely disposed notches, a unitary fuse structure contained in said tube and projecting through the slots in said disks, said structure having notches adapted to embrace the flanges of the caps and means for limiting the relativerotation of the caps and unitary structure.

In Witness whereof, I subscribe my signature, in the presence of' two witnesses.

JOHN E. WOOD. Witnesses: WALDo M. CHAPIN, REUBEN LOUER.

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