US805154A - Fuse-terminal. - Google Patents

Description

N0- 805,154. PATENTED NOV. 21, 1905. H. E. PROGUNIERE FUSE TERMINAL.

APPLICATION FILED APR. 3, 1903.

.. mun uz| UNITED STATES PATENT OFFICE.

FUSE-TERMINAL.

Specification of Letters Patent.

Patented Nov. 21, 1905.

Application filed April 3, 1903. Serial No. 150,878.

To all whom it may concern:

Be it known that I, HENRY E. PRocUNIER, a citizen of the United States, residing at Oak Park, in the county of Cook and State of Illi nois, have invented new and useful Improvements in Fuse-Terminals, of which the fol lowing is a specification, reference being had to the accompanying drawings, forming a part thereof.

The purpose of this invention is to provide a conveniently applicable device of the nature of a lightning-arrester in connection with fuse-terminals for telephone or telegraph cables and like purposes, the same being specifically designed and adapted for use with the fuse-terminals which are shown in Letters Patent granted to me dated Novemger 28, 1899, No. 637,894, for terminal head- The invention consists of the features of construction of the terminal and associated parts, including the lightning-arresting device, which are set out in the claims.

In the drawings, Figure 1 is a perspective view of a portion of a fuse-terminal head, showing fuse-terminals provided with my improved device. Fig. 2is a partly-sectional detail elevation showing one of the terminals on a larger scale, the base or support being shown in transverse section. Fig. 3 is a view similar to Fig. 2, showing the fuse connection and the lightning-arrester withdrawn from operative position and shown in the positions in which they are respectively held for insertion. Fig. 4 is an axial section of the fuseterminal with lightning-arrester in place.

Fig. 5 is a View similar to Fig. 2, showing a.

heating-coil in the fuse connection. Fig. 6 is a section at the line 6 6 on Fig. 3. Fig. 7 is a view similar to Fig. 6, showing a modification.

In the above-described drawings, A repre sents the box or terminal-head into which the cable-wires are led at the bottom and con nected severally to the inner ends of the insulated terminals, respectively, the several line-wires being attached to the exterior arms of the respective terminals. The terminalpost or fuse-terminal comprises the copper or brass central element 1, having at the outer end the offset and rifted finger 2. Onto the stem of this central element there is first passed a metal washer 3, which stops against the finger 2. Next back of this washer upon the stem of this central element there is an insulating-sleeve 4, which is reduced from the end remote from the washer 3 back to a shoulder 5. Onto this reduced portion the copper finger-piece 6, having suitable eye 7, is passed back to the shoulder 5 and is followed by an insulating sleeve or washer 8, between which and the shoulder the finger-piece is held securely when the terminal is clamped in place. The reduced end of the insulatingsleeve 4 extends beyond the washer or sleeve 8 a distance srrtlicient to guard and insulate the central elementl through the thickness of the wall of the terminal-box A, an insulating-washer 9 being applied at the inner end to complete the insulation, said washer being guarded by a metal washer 10 outside of it, and a nut 11 on the threaded inner'end of the central element 1 serving to bind all of the several parts of the terminal together and to the wall of the box.

The finger-piece 6 at one end is adapted for binding the line-wire to it, and at the opposite side of the post it has two lugs 12 12, which are turned up from its opposite lateral edges to form between them a rift or slot in the same plane with the rift 2 in the offset arm 2 of the element 1, these rifts being designed and adapted to receive the spring contact-fmgers 13 13 of the fuse-plate 14, said plate of insulating material having the fusewire 16 wrapped about it connecting the spring-fingers 13 13, each pair of which is made of a single strip of spring metal folded to embrace the insulating-plate, a tang 13 struck from one fold being protruded past the inner edge of the plate 14 through an aperture in the opposite fold and clenched down outside the latter to hold the plate 14 securely between the folds of the finger. The circuit is completed, as will be understood, by the insertion of this fuse-plate, electrically connecting the central element 1 with the finger piece 6. Said finger-piece is extended from the point at which the lugs 12 12 are folded up to grasp the fuse-plate, forming a spring-finger 17, which projects back of the inner end of the fuse-plate parallel with the outer surface of the wall of the box Aand along the surface of said wall. Extending under the entire row of similarlyprojecting spring-fingers from the several terminal-posts there is secured a conductingplate 18, properly connected with the ground and hereinafterv called the ground-plate. Between this plate and the several spring-fingers 17 there are interposed the so-called lightning-arresters, being two carbons 20 20, separated by a thin disk of material, such as mica or silk 21, of proper non-conducting quality. The device comprising these three elements-.to wit, the two carbons and the interposed mica or silk element ofl'ers so great resistance to the passage of any current which may come in on the line-wire that such current will pass by way of the fuse-wire unless and until it is sufliciently strong to melt the latter, and then it will pass from the spring finger 17 through the carbons and forming an are past or through mica to the ground-plate will be dispersed without injury to the instrument. For convenience in applying and retaining the carbons 20 20 they are formed with shallow grooves upon their opposite surfaces, which make the contact with the spring-linger 17, on the one hand, and the ground-plate 18, on the other hand. The spring-finger is adapted to run in the groove of the piece next to it, and the ground-plate preferably has guide ribs or bosses, as 19 19, struck up from its surface to similarly engage the groove of the other carbon piece. The construction of the carbon and mica device broadly is not new, being used for like purpose in other situations. Its detail construction and relation of the parts to this instrument is of my invention.

Telephone and telegraph lines are liable to be exposed to excessive currents by the crossing of wires carrying heavier currents under circumstances which may not immediately melt the fuse-wire when the construction is such as above described, and such excessive charge passing into the cable is liable to work injury at the exchange. To defeat such. injury, a fuse comprising a heating-coil may be interposed in the position occupied by the fuse-plate above described. In Fig. 5 I have shown such a device, 25 representing the heat-coil, whichis soldered to the light springfinger 26, provided on the finger-piece, instead of the lugs 12 12 of the other construction and tending to spring away from the end of the heat-coil when detached there from by the melting of the fuse-wire, leaving the spring-linger 17 to carry the current through the carbons, as in the other construction.

Some features of the construction above described should be specially noticed as affording certain special advantages.

First. The line-wire, it will be noticed, is attached to the terminal-post at a point near the base of the latter, while the conductors which enter the terminal-head from the cable receive said current beyond the fuse at a point much more remote from said base, the post being insulated over the whole extent of the intervening distance. A highpotential current accidentally getting onto the line-wire would with this construction find the greatest body of metal, and consequently its easiest line of passage at the base, and with the construction above described it is separated from ground connection only by the thickness of the thin sheet of mica or silk. In case either the fuse is melted by sudden overcharge or the heatcoil operates to melt it in the case of what is commonly called a sneak-current the current is certain to take the path to the ground rather than to form an arc across the wide gap created by the melting of the fuse-wire.

Second. The specific construction of the post comprising the insulating- sleeves 4 and 8, between which the finger-piece 6 is bound, and the specific construction by which the nut at the inner side at the same time clamps the finger-piece in place and binds the entire post to the box render the attachment and detachment of this element andany adjustment which it may require easy and convenient.

Third. The making in one piece of the finger-piece for the attachment of the fuse and the finger for making contact with the carbons and the relation of that finger-piece to the wall of the box on which the post is mounted renders the whole most conveniently accessible and easy to repair and adjust, and the construction in both these respects is less expensive than one in which two or more points of support are necessary.

Fourth. The construction of the fuse-plate with spring-fingers 13, adapted to be entered between rigid parts and to make sure contact by reason of the resiliency of said spring-[ingers, is to bedistinguished from the common construction in which the fuse-plate or fuseholding device has a rigid finger requiring spring contact elements for its engagement.

I claim- 1. I11 a fuse-terminal in combination with a base or supporting plate, a conducting-post having a terminal for a fuse connection; an insulating-sleeve on the post stopped at one end thereon and reduced back from the other end to extend into the base and form a shoulder; a second insulating-sleeve on the reduced portion of the first between said shoulder and the base a conducting-plate on said reduced portion between the shoulder and the second sleeve having a second terminal for holding the fuseplate; an insulatingwasher on the post at the opposite side of the base from said second sleeve; nuts on. the inner end of the post for binding all the parts together by longitudinal stress.

2. In a fuse-terminal, in combination with a base or supporting plate, a conducting-post extending through the plate having at one side of the plate a fuse connection; insulatin sleeves on the post stopped longitudinflly in opposite directions by the post and the plate respectively; a conducting-plate penetrated by the post and bound between the sleeves, one of the latter having a reduced portion which passes within the plate to insulate it from the post, and insulated the plate to space and insulate the post therenieans for binding the post to the plate. from, and insulated means for binding the 3. In a fuse-terminal, in combination with post to the plate. I 5 a base or supporting plate, a conducting-post In testimony whereof I have hereunto set 5 penetrating the plate and having at one side 'my hand, in the presence of two witnesses, at of the latter a fuse connection; insulating- Chicago,1llin0is,this 17th day of March, A.D. sleeves on the post stopped longitudinally in 1903. opposite directions by the post and plate respectively; a conducting-plate penetrated HENRY PROCUNIER' 10 by the post without contact therewith and In presence 0f bound between the sleeves, one of the latter FRED G. FISCHER, having a reduced portion which penetrates EDWARD T. WRAY.

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