US2204299A - Repeater circuit breaker - Google Patents

Description

Filed Sept. 23, 1936 3 Sheets-Sheet 1 Irp- L i Mmm g 0 June 11, 1940.l G, L, CARUSLE 2,204,299

REPEATER CIRCUIT BREAKER Filed Sept. 23, 1936 3 Sheets-Sheet 2 June Il, 1940. G, L CARUSLE 2,204,299

REPEATER CIRCUIT BREAKER Filed Sept. 23, 1936 5 Sheets-Sheet 5 Patented June 1l, 1940 UNITED STATES PATENT OFFlCE REPEATER CIRCUIT BREAKER George L. Carlisle, Greensburg, Pa., assigner, by mesne assignments, to Railway and Industrial Engineering Company, Greensburg,

poration of Delaware Pa., a cor- This invention relates to repeater circuit breakers, and particularly to multiplefuse constructions of the type in which the fuses are successively connected into a circuit as an overload results in the blowing of an adjacent fuse.

An object of this invention is to provide a repeater circuit breaker including a plurality of 'pairs oi terminals between which drop-out fuses are removably supported, and a plurality of switches for successively connecting one terminal of each pair to the corresponding terminal of the next pair when the associated fuse blows. An object is to provide a repeater circuit breaker or fused cutout including a plurality of r sets of terminals removably supporting drop-out fuse units, and connecting switches on the hinge terminals of the several sets for progressively connecting the hinge terminals to a line as the fuse units blow and drop to inoperative position. A further object is to provide fused cutouts, and multiple fused cutouts of the type in which a fuse unit is wedged between a pair of vertically spaced terminals and retained in position only so'long as the fuse remains intact, and in which a stop is provided for initially stressing theupper ter-I minal and for limiting the movement of the fuse unit into the upper terminal.

These and other objects and advantages of the invention will be apparent from the following specifications when taken with the accompanying drawings in which:

Fig. l is a side elevation of an embodiment of the invention with parts shown inr section as viewed on line I---I of Fig. 2; 'one fuse being shown in blown or inoperative position;

-Fig. la is a fragmentary sectional view substantially on line Ia-Ia of 'Fig- 3;"

Fig. 2 is a front elevation of the same, but with the blown fuse omitted and with ysome parts shown in section;

Fig. 3 is a top plan view of the upperterminals; and l Fig. 4 is a top plan view of the lower terminals and their supporting insulator.

In the drawings, the reference numeral I identifies a cylindrical insulator whichis be mounted in substantially vertical position upon a support, not shown, by appropriate means such as the clamp 2. An elongated plate or strip 3 is carried by the upper insulator cap 4 to support a` plurality of upper or jaw terminals that are adapted to exert a pressure on and approximately along the fuse units. As illustrated, the jaw terminals include a pair of spaced and approximately parallel members 5 that, preferably, are

formed of a single resilient rod. ,The rear ends of the jaw members overlie the plate 3 and engage in notches in the edge of the channel bar 6 which is clamped to plate 3 by the bolts l. The rod members 5 extend forwardly from the plate 3 and may have loops 8, for greater resiliency, between their anchored ends and their outer flaring ends 9 which form a jaw or guide for receiving the upper end of a fuse unit, These guide portions 9 of the side members preferably are flared upwardly from the seat portions I0 which are to engage the fuse unit and which may be, and preferably are, substantially straight sections extending tangentially to the path of movement of the contact portions of the fuse units. The movement of the fuse units into the jaw terminals is limited, las will be explained hereinafter, by a stop bar II that extends transversely beneath the rod members 5 adjacent the seat portions, and which is so positioned as to establish an initial stress in the rod members 5. The stop bar II has lugs I2 that engage and position the rod members 5, and preferably, the -stop bar Ii and clamp bar 6 are formed as a single skeleton unit, being connected by integral struts I3. The conductor I4 from the live or power side of the circuit is connected to the upper terminals in any desired manner, for example by a clamp I5 that is integral with the clamp bar 6;

The several lower or hinge terminals are car- 'ried byv a transversely arranged insulator IB which is mounted on the lower end of the insulator I by a bracket I1, and a cooperating clamp which, in the case of an odd number of fuse units, may be integral with the central lower terminal. As shown, lugs I8 are provided at the upper and lower edges of the terminals; the upper lug of the central terminal I9 being directly bolted to the bracket I1 while the lower lug is secured to the bracket by a bolt 2D. The other lower terminals are secured to the circumferentially grooved insulator I6 by U-bolts 2| that extend around the insulator and pass through the lugs- I8.

Each lower or hinge terminal I9 has an inner or boxlike section that is seated against the insulator I6, and forwardly extending side arms of skeleton form that terminate in hooks or seats 22 that receive the trunnions of the fuse units.

The lower terminals are preferably of identical' construction but, for convenience of description, the numerals ISB, IBR are applied to the terminals at the right and left, respectively, of the central terminal I9 of Fig. 2. The clamp 23 for connection to the protected conductor 24 is se- 'ill so long as the fuse 39 remains intact.

cured to a boss or lug 25 at the inner face of the outside lower arm of the terminal ISB, and the correspondingly located lugs 25 of the other terminals carry resilient contact jaws 26 for cooperation with contact arms 21 that are pivotally mounted on terminals I 9B and I9. Each contact jaw 2G is a resilient strip of approximately U-form with a long lower leg that normally rests against the extension 25 of lug 25 and extends below the terminal to form a. guide for the cooperating contact arm 21. As indicated by the position of contact arm 21 of terminal 59B in Fig. 4, the extension 25 constitutes a stop which prevents the contact arm 21 from swinging beyond the point at which it will be pressed against the lower face of the terminal by the resilient strip 26. The inner ends 21 of the contact arms extend upwardly through the lower walls of the terminals ISB and I9 and are journalled in bosses 28 in the upper walls of the terminals. Pins 29 are passed through the contact arms 21 above the lower wall to secure the contact arms in place. Each contact arm 21 normally rests in a latch seat 39 on the side arm of the associated terminal, and is urged towards the contact jaw of the adjacent terminal by a coil spring 3I.

The outer end of each contact arm 21 extends across the gap between the arms 22 of the associated terminal and may be reversely bent to form a hook which. may be engaged by the usual insulated fuse puller to return the Contact arms i? to their latch seats 30.

The fuse units are of known design and comprise elongated expulsion tubes 32 of insulating material having upper conducting members 33 provided with transverse lugs 34 that engage the seat portions I9 of the jaw terminals, and lower conducting members 35 upon which the yokes are pivoted by pins 31. Trunnions 38 on the yokes are removably received in the hook arms 22 of the hinge terminals and the fuse units are retained in wedged position between the upper resilient jaw terminals and the hinge terminals The fuse may be of the fusible or the explosive type and is secured between the upper end cap 40 and the clamp bolt 4I on the yoke 35.

The fuse 39 should be drawn taut to press the stop 42 of yoke 3G against the extension 43 of the conducting member 35 at the lower end of the expulsion tube. It frequently happens, however, that the fuse 39 is loosely drawn, as indicated in Fig. l, and an appreciable gap is left between the stop surfaces 42, 43. A substantial angular movement must take place before there is any appreciable decrease in the distance between the trunnions 38 and the upper contacts 34 when the yoke trunnion is located close to the axis of the tube 32 and at a substantial distance from the trunnions 33. The effective length of the fuse unit therefore does not depend upon a close contact of the stop surfaces 42, 43 and, by initially stressing the rod members 5 of the jaw terminal i against the stop bar II, the fuse units will be firmly wedged in place in spite of a loose adjustment of the fuse wire 39. In actual practice with an initial pressure of the rod members 5 on the stop bar I I of the order of about l5 pounds, it has .y been found that fuse units of from one to three feet in length can be supported in the terminals with as much as one to one and one-half inch slack in the fuse wires, The stop bar II has the additional function of preventing the angular movement of the fuse tube assemblies beyond their intended operative positions. The resilient rod members 5 present the possibility that, except for the rigid stop bar II, the upper end of a fuse assembly may be inadvertently forced so far beyond its intended position that it cannot drop to inoperative position when the fuse blows.

The parts are illustrated in the positions which they occupy when the rst fuse has blown, the fuse of the second or central set of terminals is in circuit, and the third fuse is in reserve. When each of the three fuse units is intact, only the fuse within the tube 32B is connected into the circuit as the contact arms 21 are retained in their latch seats 3G. When the fuse blows, the yoke 36 of tube 32B is no longer held against movement about its pivot 31, and the fuse unit collapses under the pressure exerted upon it by the upper spring terminal members 5. The fuse assembly 32B therefore drops into inoperative or blown position, as shown in Fig. l, and in so doing moves the contact arm 21 of that unit out of its latch seat 30 and the spring 3| rotates the contact arm 21 into the spring contact jaw 26 of the next adjacent terminal. The fuse 39 of tube 32 is therefore connected in the circuit when, as illustrated, the Contact arm 21 of terminal IBB is engaged with the Contact jaw 25 of terminal I 9. The third fuse or unit 32B, is in reserve position as the terminal I SR is insulated from terminal I9. The terminal ISR- will be connected to the line 24 through the Contact arms 21 and terminals I9, ISB when the fuse 39 of tube 32 is blown by an overload. The tube 32 is ejected from the upper or jaw terminal in such an event,

and the dropping of tube 32 will force the contact "i arm 21 of terminal I9 out of its latch seat 30 and the terminals I9 and ISR will thus be connected. Terminal I9 was previously connected to terminal ISB when the first fuse failed, and therefore the fuse of the third unit is automatically connected into the circuit.

The repeater action is initiated by the dropping of a fuse tube, but the weight or momentum of the tube is not relied upon to eilect the closing of the switch to the succeeding fuse unit. Accumulations of dirt and of sleet or ice may retard the dropping of a fuse tube, but the tube will develop sufiicient force to release the contact 21 from its latch seat 30 even under the most disadvantageous conditions, and the spring 3l throws the contact 21 to its seat 26 with sufiicient force to dislodge sleet and ice, thus ensuring a positive contact engagement that is independent of the rate at which the fuse tube drops to opencircuit position.

It is to be understood that the invention is not limited to the specific constructions herein illustrated and described, nor to any particular number of fuse units, and that many variations in the size, shape and relationship of the parts fall within the spirit of my invention as set forth in the following claims.

I claim:

l. A repeater fuse assembly of the type in,- oluding a plurality of drop-out fuse assemblies normally retained in operative position between pairs of upper and lower terminals, and means for successively connecting said fuse assemblies into a circuit `as the fuse element of. each fuse assembly except the last is blown, characterized yby the fact that said means comprises means connecting all upper terminals in parallel, means for connecting only the lower terminal of thc irst fuse assembly to the circuit to be protected,

switch member carried by each lower terminal 'f Cil except that of the last fuse assembly, a contact seat for each switch member on the lower 'terminal next adjacent to that lower terminal which carries the switch member, spring means urging each switch member towards its contact seat, a latch seat lor each switch member on the terminal carrying that switch member, said springmeans normally retaining each switch member in its latch seat to prevent closing movement of said switch members, and means operable upon the blowing of each fuse element except that of the last fuse assembly for releasingthe associated switch member from its latch seat.

2. In a repeater fuse assembly, a vertically disposed insulator, a plurality of jaw terminals mounted at the upper end thereof and electrically connected to each other, a plurality of hinge terminals mounted at the lower end of said insulator and insulated from each other, a drop-out fuse assembly supported on each hinge terminal and maintained thereby in engagement with the corresponding jaw terminal only so long as the fuse element of the fuse assembly remains intact, a plurality of switches each including a contact member pivotally mounted on one hinge terminal and a seat member carried by the next adjacent hinge terminal, means latching each contact member to the hinge terminal carrying the same, means positioned to be engaged by the fuse assembly of each hinge terminal having a contact member for releasing the respective contact members from their latching means, and spring means for closing each contact member upon its seat member when released from its latching` means.

3. A repeater fuse assembly as claimed in claim 2, wherein each jaw terminal comprises a pair of resilient elements supported by and at the upper end of said insulator, and rigid stop means limiting the movement of said fuse assemblies into engaging position with said resilient rod elements.

4. A repeater fuse assembly as claimed in claim 2, wherein each jaw terminal comprises a pair of resilient rod elements supported by and at the upper end of 'said insulator, and stop means limiting -the movement of said fuse assemblies into engaging position with said resilient rod elements, said stop means being positioned to maintain said resilient rod members under an initial stress when the fuse assemblies are not engaged therewith.

5. In a fuse, the combination with a lower hinge terminal having means for pivotally supporting a `fuse assembly, a resilient jaw terminal having a rigidly mounted inner end and a flexible outer end for exerting pressure approximately alongY a fuse assembly when the latter is supported on the hinge terminal and rotated upwardly into wedging engagement with said resilient jaw terminal, of stop means preventing movement of the iiexible outer end of said jaw terminal into unstressed position when the fuse assembly is released therefrom, whereby an initial stress is established in said resilient jaw terminal.

6. A fuse as claimed in claim 5, wherein said stress-maintaining means comprises a stop for limiting the movement of the fuse assembly into the said jaw terminal.

1. A fuse as claimed in claim 5, wherein said resilient jaw member comprises a pair of resilient rod elements, and said stop means comprises a substantially rigid member positioned beneath said rod elements at the region where said rod elements are engaged by a fuse assembly.

8. A fuse as claimed in claim 5, wherein said resilient jaw member comprises a pair of resilient rod elements, and said stop means comprises a substantially rigid member beneath said rod elements and extending across the gap between the same at the region where they are engaged by a fuse assembly.

9. In a drop-out repeater fuse assembly, a terminal for removably receiving a drop-out fuse unit, said terminal comprising means defining a seat in which said drop-out fuse unit is supported in one position while the fuse is intact and in another position when the fuse is blown, a contact arm mounted upon said terminal, means urging said contact arm in the direction of a second terminal positioned laterally of the rst terminal, latch means normally Ipreventing movement of said contact arm, and a contact seat on said terminal for cooperation with the contact arm` of a third terminal.

10. In a multiple fuse assembly, terminal means for supporting a plurality of fuse units in substantially parallel and approximately vertical position, said terminal means including for each fuse unit a pair of spaced resilient members for exerting pressure approximately along the associated fuse unit, and substantially rigid means extending across and beneath said pairs of spaced resilient members to limit the movement of said fuse units into engagement with said members.

11. A multiple fuse assembly as claimed in claim 10, wherein said rigid means is positioned to place said resilient members under an initial stress prior to the engagement therewith of said fuse units.

12. In a fused cutout, the `combination with a pair of vertically spaced terminals, the upper terminal comprising a pair of spaced members and means resiliently urging said members towards the lower terminal to exert pressure approximately along a fuse unit, and a drop-out fuse unit seated on the lower terminal and wedged beneath said spaced members, said fuse unit including means operative upon the blowing of the fuse to permit the ejection of the fuse unit fro-m the upper terminal by the pressure exerted thereon, of stop means positioned 4beneath and initially stressing said spaced members, said stop means limi-ting the movement of the fuse unit into the upper terminal.

13. A repeater fuse assembly of the type including a plurality of drop-out fuses, sets of vertically spaced terminal means normally supporting said' fuses in approximately vertical position, and switch means for successively connecting a fuse in the circuit as the next adjacent fuse blows; characterized by the fact that said switch means includes, for each fuse except the last, a switch arm pivotally mounted on a lower terminal means for arcuate movement in an approximately horizontal plane, and a seat for each switch arm on the next adjacent lower terminal means.

14. A lower terminal for a repeater fuse comprising a terminal member having means for attachment to an insulating support, said member having a pair of horizontally spaced side arms, seats on said arms for pivotally supporting a fuse assembly, a contact arm pivotally supported on said terminal member for movement in an approximately horizontal plane, spring means tending to move said contact arm, a latch seat on one side arm in which said contact arm is normally retained by said spring means, and means positioned for actuation by the dropping of a fuse assembly pivoted on said terminal member to release said contact arm from said latch seat.

15. A lower terminal for a repeater fuse comprising a member having means for attachment to an insulating support, spaced side arms on said member having seats for pivotally receiving a fuse assembly, apertured means on one side arm for the attachment of an element for connecting the member electrically to a local circuit, a latch seat depending below the other side arm, and means on said member for supporting a contact arm for movement about an approximately vertical axis.

16. A terminal as claimed in claim l5, in combination with a contact arm pivotally mounted in said supporting means and normally seated in said latch seat, and spring means tending to rotate said contact arm away from the rst side arm, said Contact arm including a portion extending across the space between said side arms for enagement by a dropping fuse assembly to release the contact arm from its latch seat.

17. A lower terminal for a repeater' fuse comprising a member having means for attachment to an insulating support, spaced side arms on said member having seats for pivotally receiving a fuse assembly, apertured means on one side arm for the attachment of an element for connecting the member electrically to a local circuit, a. latch seat depending below the other side arm, and means on said member adjacent the second side arm for supporting a contact arm for movement about an approximately vertical axis.

18. In a repeater fuse, a plurality of horizontally spaced and approximately vertically arranged fuse units; each unit including a fuse assembly mounted between an upper and a lower terminal, contact arms pivotally mounted upon certain of said lower terminals for movement in an approximately horizontal plane, a latch seat for each contact arm on the lower terminal supporting the same, a contact seat for each contact arm on the adjacent lower terminal, the seats for each contact arm being in approximately the same horizontal plane, and means operable upon the blowing of any fuse assembly except the last for closing the associated switch arm upon the contact seat of the lower terminal of the next adjacent fuse unit.

19. A repeater fuse assembly of the type including a plurality of sets of vertically spaced upper and lower terminals, means electrically connecting the upper terminals to each other, drop-out fuse units mounted between the terminals of each set, and switch means for successively connecting each lower terminal to the next adjacent lower terminal; characterized by the fact that said switch means includes for each lower terminal except the last a springpressed contact arm movable angularly about a vertical axis and a seat for the same on the adjacent lower terminal, and means normally latching each contact arm in open circuit position, said latch means including a member engageable by the associated fuse assembly after f:

the latter has moved through approximately its full range of drop-out movement to render the latch means inoperative, whereby the springpressed contact arm may move to closed circuit position.

GEORGE L. CARLISLE.

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