US1761760A - Fuse cutter - Google Patents

Description

June 3, 1930.

Filed-May 2, 1927 3 Sheets-Sheet 1 v 1 511 1 W w 4 m F (gc 5 l J lllllllllllllllllllllllllllllll II llllllllmll .INVENTOR Jizmefl Vim flerfiqyarli ATTORN EY June 3, 1930.

J. VAN DER BOGART usE'cuTTER Filed May 2, 1927 5 Sheets-Sheet 2 x W f Jmil iii liliiiiiiiii WITN ESSES INVENTOR fame; Van Derfiqyari.

ATTORNEY June 3, 1930. J. VAN DER BOGART FUSE CUTTER Filed May 2, 19,27 3 Sheets-Sheet 3 In ullhfi WITNESSES t 15 INVENTOR I 1 y" i F v James Vkmflarfigazi. if? M 47W ATTORNEY:

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Patented June 3, 1930 UNITED STATES PATENT orrrce JAMES. VAN DER BOGART, 0F OSSINIHG, NEW YQRK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEEV YORK FUSE CUTTER Application filed May 2, 1927.

This invention relates to fuse cutters, an ob1ect of the invention benig to provide means of cutting and spreading the cut ends.

is applied to, and provides a means for extinguishing any are formed, thus breaking the current completely.

It is common. knowledge that electrical fuses are designed with an appreciable tinielag; that is to say, a fuse does not melt instantaneously at its rated current, or even at a current of several timesthis value. Standard specifications require that a fuse shall carry twice its full, rated current for thirty seconds before melting Reference to data collected on this subject will disclose that a metal fuse may carry for a considerable number of seconds a current several times that at which it is rated This being the case, it often happensthat grave damage may be done to an electrical circuit or apparatus thereof by an excessive current caused by a short-circuit, or other means, which current though being sufficient, and sustained long enough to destroy apparatus, is, nevertheless, insuflicient to melt the fuse in the circuit before this damage has been done, for the reasons just mentioned.

It is perfectly evident that if some practicallyinstantaneous means of mechanically cutting a fuse be provided, the circuit will be more fully protected than it was before the installation of this device. If the action be quite instantaneous and thorough, all damage to the circuit can be averted. lvherefore, I propose the following device: An apparatus, which through manual, automatic, or a combination of manual and automatic control, and by any actuating power, such as compressed air or an electromagnet mechanism, is arranged to open any electrical circuit, or network of electrical circuits by cutting the metal fuse, or fuses, thereof, and spreading the two parts of Serial No. 188,389.

each sufiiciently far apart or by any other means extinguish the are formed by the current at the parting of the fuse.

I have concentrated my attention upon a specific oevice of this sort, applicable to electric locomotives and electric motor cars, operating on rail-ways. The specific apparzu tus may be described as follows 2 A series of devices applied to electric locomotives or'cars having ribbon fuses in the main current supply circuits and located immediately adjacent the third rail, trolley, or other current collectors, the operation of which devices, by manually controlled compressed air, will break all current between apparatus and the current collectors, by cutting the aforementioned fuses and, spreading the leaves thereof su'liiciently far apart to extinguish any are formed.

This invention contains advantages, some of which may lee-enumerated as follows:

The invention of a fuse cutter, as herein before described, which complements the function of metal fuses, and supplants such protective devices as circuit breakers and overload relays.

A device which will open an electrical circuit under load where other means fail.

A means of cutting meta-l fuses and parting the same, at once extinguishing any are formed.

A fuse cutter which may be arranged for manual or automatic control, at hand or from a remote point.

A fuse cutter which serves to break all cu"- rents at their source, so to speak, thus protecting not only all locomotive apparatus but also the circuits and cables between these apparatus and the current collectors. The current is killed at a point external to the cab and immediately adjacent tne current collectors, such for example, as the third rail current collecting shoes of the locomotive, which is the only safe method of protecting cab equipment and occupants.

A fuse cutter which by virtue of its very ruggedness and simplicity is uniquely applicable to electric locomotives and cars, where service requirements are severe and exacting.

Ii fuse cutter which through variations device or and elaborations in design is applicable to more delicate or complicated electrical. circuits, so long as the latter are fused.

\Vith these and other objects .in view, the invention consists in certain novel features of construction and coi'nbinations and arrangements of parts, which will be more fully hereinafter described and pointed out in the claims.

In the accompanying drawings Figure 1 is a diagrammatic plain view illustrating a plurality of my improved fuse cutters connected to a common source of air supply and operating from either end of an electric locomotive or other body on which the apparatus is supported;

Figure 2 is a view mainly in side elevation and partly in section showing my improved sealed cut out cock;

Figure 3 is a view mainly in elevation and partly broken away illustrating my i1nproved fuse cutter in connection with an ordinary standard type of fuse box;

Figure lis a view similar to Figure 3 showing the fuse cut and the ends thereof spread apart by my improved device;

Figure 5 is a view in section on the line 55 of Figure l;

Figure 6 is a top plan view of Figure l;

Figure 7 is a perspective view of my improved fuse cutter.

1 represents a support, which for purposes of description we may assume to be an electric locomotive, but as above described the invention is applicable to any apparatus and will be described for convenience in connection with an electric locomotive.

2 are the air cylinders of my improved fuse cutters. \Vhere the electric locomotive is arranged to operate on a third rail. system ordinarily a plurality of third rail contact shoes are carried at both the front and rear ends of-the locomotive on each side thereof so as to insure continuity of current supply over gaps in the third rail which may be locat-ul on either side of the track. More over, these current collecting shoes customarily are carried directly on the trucks of the locomotive so as to facilitate proper alignment of the current collecting shoes with the third rail conductor. l vith such a locomotive the most advantageous position for the fuses in the main current supply circuits is directly adjacent the third rail shoes since with. such location the blowing or opening of the fuses effectively insulates all circuits on the locomotive from the third rail supply source. Thus, as illustrated diagrammatically in Fig. 1, the several. pairs of my improved fuse cutters 2 may be assumed to be located directly adjacent the third rail collecting shoes at each of the four corners of the locomotive. 3 is an air supply tank. f is an enginemans brake valve. 5 are pipes connecting the tank 3 with the respective cylinders 2, the air through said pipes being controlled by a pair of cocks 6 located adjacent the respective ends of the locomotive so that the air to the fuse cutting devices may be controlled from either end of the locomotive.

These cocks 6 have their operating arms 7 held by breakable or removable seals 8 and each is vented, as indicated at 9, to guard. against any leakage effectually forcing down the pistons and cutting the fuses and also permitting venting to allow the cutters to return to normal position.

My invention has particularly to do with the means for severing the fuses and a preferred form of such means is illustrated in detail in Figures 3 to 7, inclusive.

10 represents the back board of a fuse box 11 which forms a fuse blowout arc chute open at the lower side, and 12 is a laminated fuse secured at its ends in the spaced apart clamping jaws 12 and 12", which are disposed at opposite ends of the are chute formed by the fuse box 11 and included in the electric circuit of the motor.

My improved fuse cutter comprises a unit, consisting of a cylinder 2 secured to the back of the fuse box 11 by means of metal straps 13 and provided with a piston 14 fixed to a rod 15 which projects through the bottom of the cylinder 2.

A coil spring 16 is located in the cylinder between the lower end of the cylinder and the piston 14 tending to press the piston upwardly. It will be understood, however, that other suitable means may be employed for holding the piston in normal position at one end of the cylinder. One of the air pipes 5 connnunicates with the upper end of the cylinder 2 so that air may be directed into the cylinder to force the piston downward.

An angle bar 17 is secured to the lower end of the rod 15 and supports a vertical 18 of fiber or other insulating material, this bar 18 being located in front of the back board 10 of the fuse box 11. The insulating bar 18 carries a spreader or block 19 at its upper end, normally located above the fuse 12, and a cutting blade 20 is carried by the block or spreader 19 in position to cut the fuse when the block is forced downwardly. As clearly shown in Figs. 5 and 7 the cutting blade 20 is pointed and provided with diverging cutting edges. This form of cutting blade is particularly adapted for severing laminated ribbon fuses of heavy current carrying capacity, such as shown in Fig. 3. lVith such fuses supported at their ends between clamps disposed at opposite ends of the arc chute, the fuses may hang loosely in catenary form, as illustrated in the drawing. The pointed cutting blade 20 is arranged for movement in the arc chute in a path intersecting the fuse as indicated in Figs. 4 and 5, so that the point of the blade first engages with the central part of the upper lamination of the fuse, Upon continued movement of the cutting blade the diverging cutting edges sever the suc cessive laminations of the fuse from the center outwards. In this way the cutting pressure of each diverging cutting edge is balanced against the other, thereby eliminating any tendency for the fuse to swing out of the path of the cutting blade.

As indicated diagrammatically in Figure 1 a plurality of these fuse cutting devices are provided in the supply circuit or circuits of the locomotive or other apparatus, all

of which will be simultaneously operated to disconnect entirely all the electrical apparatus and circuits on the locomotive from the supply source when one of the cocks 6 is I opened.

The operation is as follows:

The enginenian upon the first indication of any electric trouble such as a short circuit, flashover, sustained arc in any apparatus, or

I any danger to himself or to other persons or equipment from the electrical current in the circuits of the locomotive, immediately opens fully the cut out cock 6 nearest him by giving the handle a sharp pull breaking the wire seal 8. The opening of this cock admits main reservoir air pressure to all of the operating cylinders 2 simultaneously and instantly. The high pressure and sudden admission of this air causes a very rapid a, and energetic movement of the pistons carrying the spreaders 19 and knives or blades 20 downwardly, cutting the fuses and holding the cut ends apart. This operation opens the circuit and maintains it open as long as desired. \Vhen the cock 6 is closed the spring 16 will return the parts to normal position, the accumulated air escaping through the vent in the cock.

VYhile I have illustrated what I believe to be a preferred embodiment of my invention, it obvious that various changes and alterations might be made in the general form of the parts described without departing from my invention and hence I do not limit a myself to the precise details set forth but consider myself at liberty to make such changes and alterations as fairly fall within the spirit and scope of the appended claims.

I claim:

1. As a new article of manufacture, a fuse cutter and spreader for a ribbon fuse including a pointed metal blade having diverging cutting edges for transversely severing the ribbon fuse each way from the center of the fuse, outward, and an insulating member for holding the severed ends of the ribbon fuse apart.

2. The combination of a fuse box having a ribbon fuse mounted th rein, and a fuse cutter and spreader operatively connected to a fuse box, and including a pointed metal blade having diverging cutting edges for cutting the fuse transversely from the center outward, and a spreader of insulating material connected to follow the said cutting blade (to hold the ends of the fuse apart after severance thereof and remotely controlled power means for quickly operating the said cutting blade and spreader into engagement with the fuse.

3. As a new article of manufacture, a remotely controlled fluid pressure operated fuse cutter and spreader comprising a movable spreader block of insulating material, a metal cutting blade mounted to move in advance of said block, a cylinder, a piston in the cylinder operatively connected to the spreader and the cutting blade, means for holding the spreader block and the cutting N blade in spaced relation with the fuse, and

means for admitting fluid under pressure to the cylinder to operate the cutting blade and the spreader successively into engagement with the fuse.

4. The combination of a fuse box forming an arc chute open at one side and having spaced apart clamping jaws disposed at opposite ends of the arc chute, a renewable laminated ribbon fuse having its ends se cured in said clamping aws with the intermediate po-rtion of the fuse centrally disposed in said are chute, and a fuse cutter and spreader operatively connected to said fuse box and including a pointed metal blade mounted for movement in said are chute in a path intersecting said fuse and provided with diverging cutting edges for cutting the fuse transversely from the center outward, a spreader block of insulating material connected to move simultaneously with and behind said cutting blade to hold the ends of the fuse apart after severance thereof, a cylinder, a piston in the cylinder operatively connected to the spreader and cutting blade, means for maintaining the piston at one end of said cylinder to hold the said cutting blade and spreader in spaced relation with the fuse, and means for admitting fluid under pressure to the cylinder to operate the cutting blade and spreader block successively into engagement with the fuse.

5. The combination of a fuse box forming an arc chute open at the bottom and having spaced apart clamping jaws disposed at opposite ends of the arc chute, a renewable laminated ribbon fuse secured at its ends in said clamping a pressure cylinder mounted vertically on said fuse box, a reciprocating piston in the cylinder, means for holding the piston at the upper end of the cylinder, a cutter blade mechanically connected with said piston to be held above said fuse and operated into engagement therewith to sever the fuse upon downward move ment of the piston in the cylinder, a spreader of insulating material connected with the cutter blade to hold the severed ends of the fuse apart, and means remote from the cylinder for admitting fluid under pressure to the cylinder to operate said piston downward therein.

JAMES V AN DER BOGART.

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