US1953392A - Repeater circuit breaker - Google Patents

Description

April- 3, 1934;

G. L. CARLISLE HEPEATER CIRCUIT BREAKER Filed Feb. 11, 1933 2 Sheets-Sheet l April'3, 1-934.- 6. CARLISLE REPEATER CIRCUIT BREAKER Filed Feb. 11', 1933 2 Sheets-Sheet 2 ill Patented Apr. 3, 1934 PATENT OFFICE REPEATEE CIRCUIT BREAKER George L. Carlisle, Gre

ensburg, Pa., assignorto Railway and Industrial Engineering Company, Greensburg, Pa, a corporation of Pennsylvania Application February 11, 1933, Serial No. 656,346

12 Claims.

This invention relates to repeater circuit breakers, and particularly to constructions of the type including a plurality of fuses that are successively inserted in the circuit as an overload results in the blowing of a previously inserted fuse.

The conditions which give rise to overloads on a power distribution line usually exist for but a short period and, as a general rule, will disappear within the short interval. required for the automatic or manual reclosing of the circuit t h was automatically opened by the existence the overload condition. Notching relays have been employed to restore the service a predetermined number of times before definitely interrupting the service in the case of an overload which. continues beyond the time interval or number of reclosing periods for which the relay system is adjusted. According to another protection system, the sir cuit breaker includes two or more fuses and the line is initially closed through the first fuse, then automatically shifted to another fuse as the one in the line circuit blows. Some proposed systerns of this type have included relatively complex apparatus for moving the fuses successively into circuit-closing position or for switching the circuit from one fuse to the next of the series.

An object of the present invention is to provide a repeater circuit breakerwhich includes a plurality of fuses and an exceedingly simple,

till

and emcient switch system for automatically placing a new fuse in circuit when one blows by an overload.

A further object is to provide a circuit brealrer, of the type stated, including a plurality of knockout fuses mounted in supporting terminals and a resilient switch arm which is automatically lifted from engagement with one fuse terminal when the fuse carried by that terminal blows, the switch arm then moving into contact with the supporting terminal of the next fuse of the set of fuses.

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

' Fig. 1 is a plan view of an embodiment of the invention which includes three fuses, the parts being illustrated in the positions which they occupy after the blowing of the first fuse and the reclosure of the circuit through the second fuse;

Fig. 2 is a fragmentary vertical section showing the. main support and one fuse assembly in side elevation; and

Fig. 3 is a perspective view of the lower or switch tifies a supporting base which is provided with openings 2 for receiving the ends of U-bolts 3 that pass around a cross-arm or other support upon which the repeater circuit breaker is to be moimted.

The ends of a strap l are welded to the base 1, and portions of this strap are bent to approximately semicircular contour to cooperate with short straps 5 to support a plurality of insulators 6. "in the case of three insulators, a central strap 1 may be welded to the base and to the strap 4 to reinforce the latter.

The upper terminal caps 8 of the insulators are connected by bracing and conducting straps 9, and one terminal cap is provided with a clamp 10 for receiving a lead 11 (not shown in Fig. 1) from the power line. The local line 12 is clamped to a conducting post 13 that depends from an insulatcr 14 which is secured to the supporting base 1. The line 12 extends beyond the post 13 and is connected to the lower terminal 15 of the end insulator and fuse assembly I. The post 13 carries a coiled spring 16 which has a free end or switch arm 1'? adapted to engage one of the lower terminals 15, the arm being provided with an eye 18 for receiving the hooked end of a switch puller.

Each lower terminal assembly includes a pair of side members 19 which terminate, at their ends remote from the supporting base 1, in hooks or seats 20 which receive and provide journals for trunnions on the fuse tubes. Towards the base 1, the side members are joined by an end bar 21 which has a seat 22 formed by notching out the upper end of a sloping face or edge 23. Beyond the seat 22, the top edge of the bar 21 is horizontal and, as soon as the end of the spring contact arm l? is raised to clear the seat, the contact arm is turned in a clockwise direction (as viewed in Fig. i) by spring 16.

The curved end 24- of a buffer spring 25 is arranged in front of the seat 22 to receive the blow from the spring arm 17 as it snaps over from the preceding unit, and to guide the arm downwardly to the lower portion of the inclined edge 23 of the end bar 21. The spring arm then moves up the edge 23 and comes to'rest in the seat 22.

1e inclination of the edge 23 of the bar 21 brings the seat 22 between the two side members 19 of the terminal member, and thus into the path of movement of a member 26 that is clamped upon the tubes 2'? of the fuse or circuit breaker units. These units are preferably of the type described and claimed in my copending application Ser. No. 634,071, filed Sept. 20, 1932, but

idem-other types of knockout fuses may be employed.

As described in said application, the tube 27 is an elongated expulsion tube of insulating material to which is fixed a lower collar 28 having trunnions 29 that are cut away at opposite sides to permit the mounting of the trunnions in and their release from the pivotal seats 20 of the terminal side members 19. The upper collar 30 has a pivoted cap 31 which carries lugs 32 for engagement ina seat formed by the reversely bent con tact horn 33 on the upper terminal 8 of the insulator assembly, the. pivot 3 1 of the cap being more remote from the axis of tube 27 than the lugs 32. The pressure exerted by the resilient contact horn therefore tends to retain the cap on the tube 27. The fuse wire 35, see unit I, Fig. 1, extends through the tube 27 and preferably terminates in an explosive cartridge, not shown, at the upper end of the tube.

When the fuse blows, the pressure within the tube rotates the cap 31 to carry the pivot 3 towards the left, as seen in Fig.2, thus releasing the lugs 32 from the contact horn 33 and permitting the fuse assembly to drop out. When this occurs,

the striker member 26 moves along the curved path, indicated by the broken line and arrow, to lift the contact arm 17 from the seat 22.

As shown in Fig. l, the contact arm 17 engages the lower terminal of the second unit II of the set of insulator-fuse units. The contact arm 17 moved automatically to that position when the fuse of unit I was blown by an overload. If the fuse of unit If blows, the contact arm 17 will move to the next terminal to place the fuse of unit III in series in the line; As illustrated, the blown fuse element of unit I has been replaced by a wire and the fuse unit may be turned up, in the usual manner, to engage the cap 31 in the resilient seat on the contact horn 33. When this is done, the spring contact arm may be moved counterclockwise, by engaging a switch puller in the eye 18. The circuit is not opened during this shifting of contact arm 17 frompunit Hback to unit I since the terminal member 15 of unit 1 is permanently, connected to-the central post 13 by the end of the line 12.

When the parts as shown in Fig. l, theline will bereclosed once when the fuse of unit II (is blown bit by an overload. The striker member 26 is preferably'omitted from the fuse assembly of the unit or the end plate 21 may be so shaped that the arm 17 cannot be forced out of its seat when the fuse I blows.

Whennew fuses are placed in all units and the contact arm 17 is in its normal position on unit I, the circuit will be reclosed twicebefore it is definitely opened by an overload. The condition of the fuses may be ascertained at a glance since each fuse assembly drops out of the upper contact hook to depend from the journals 20 when the fuse blows.

A short, but appreciable, time interval should elapse between the initial, interruption of the line and the restoration of service. When the fuse in service blows, the expulsion tube and'fuse assembly fall out under the infiuenceof gravity panacea erted by the spring 16. As this time interval does not vary with the extent of the overload,

it is obvious that the total time interval is independent of the degree 'of overload.

The invention is not limited to the use of any particular number of units, nor to the described construction of the fuse units. The circuit breaker may be operated as a simple disconnect switch by pulling out the fuse which is in the line circuit. When done with ordinary care, this operation will not affect the position of the contact arm 1''? since the tube 27 must swing considerably beyond its normal depending position to bring the striker member 26 into engagement with contact arm 17.

While I have illustrated and described a preferred embodiment of the invention, it will be understood that there may be considerable lati tude in the design, construction and relative arrangeinent of the several component parts of repeater circuit breakers without departing from the scope of the invention as set forth in the following claims.

I claim:

1. In a repeater circuit breaker, a mounting for a plurality of knockout fuses comprising a base, a plurality of insulators carried by said base, a pair of fuse receiving terminals on each insulator, a contact arm mounted on said base and spring pressed to move in a path which will carry it into engagement with correspondingly located terminals on said insulators, a metallic connection betweeen the other terminals of said pairs of terminals, a seat for said contact arm on each of said first terminals, the seat on each terminal positioning the contact arm in the path of movement taken by a fuse mounted in that terminal when the said fuse blows under an overload, and line terminals for said metallic connection and said contact arm respectively.

2. The invention as set forth in claim 1, in combination with a permanent metallic connection of negligible resistance between the contact arm and the first seat terminal normally engaged thereby.

3. In a repeater fuse, a support, a contact arm carried by said support and spring urged for piv- [I otal movement, a plurality of insulators, a terminal on each insulator and in the path of ar cuate movement of said contact arm, means on each terminal providing a pivotal support for a knockout fuse, a latching terminal cooperating with eachof said first terminals, and a notchediseat on each of said first terminals for receiving the contact arm and supporting the same in the path of movement of a striker element carried by a knockout fuse mounted on that terminal.

i. In a fuse, a support, an insulator vertically carried thereby, a seat terminal at the base of said insulator, a latch terminal at the top of said insulator, means on said seat terminal for pivotally mounting a fuse assembly, means on said latch terminal for yieldingly retaining the upperend of a fuse assembly only so long as the fuse does not blow, and a seat on said seat terminal for supporting the end of a contact arm in position to be engaged by and forced from the said seat by a fuse assembly which is released by said latch terminal.

5. In a repeater fuse, a plurality of insulator pairs of fuse supporting terminals carried thereby, seats on corresponding terminals of said I pairs for receiving a contact arm, and a contact arm spring pressed to move to the seatof a succeeding terminal when forced out of the seat on one terminal, said seats being positioned on said terminals to support the contact arm in the path of movement taken by a knockout fuse when the latter blows under an overload.

6. In a repeater circuit breaker, a base, a plurality of pairs of terminals for knockout fuses, fuses mounted in the respective pairs of terminals, a conductive connection between corresponding terminals of the several pairs, a movable contact arm, the other terminals of each pair having seats in the path of movement of said contact arm, means tending to move said contact arm, and means on said fuses and operable when the fuse is blown out to force said contact arm out of the seat on the terminal engaged by the respective fuse.

7. In a repeater circuit breaker, a plurality of pairs of seat and latch terminals, a knockout fuse pivotally mounted on each seat terminal and yieldingly latched to the corresponding latch terminal, a seat on each seat terminal, a contact arm mounted for movement in a path which includes each of saidseats, spring means urging said contact arm to move to a succeeding terminal and seat when released from the seat of one terminal, and means on said knockout fuses for forcing said contact arm out of itsseat when the fuse blows and pivots upon its seat terminal after release from its latching terminal.

8. In a repeater fuse, a support, a contact arm pivotally mounted on said support, spring means urging said arm to move in an arcuate path, a plurality of fuse supporting terminals in the path of movement of said arm, notched seats on said terminals providing abutments against which the arm will come to rest, a fuse retaining terminal cooperating with each supporting terminal,

knockout fuses mounted in each pair of supporting and retaining terminals, and means actuated by the blowing of a fuse for forcing the contact arm clear of the corresponding abutment, whereby the spring means forces the contact arm into engagement with the seat of the succeeding fuse when one fuse blows;

9. In a repeater fuse, the combination with a support, and a spring-pressed arm mounted thereon for movement in an arcuate path, of a plurality of pairs of supporting terminals for knockout fuses, one terminal of each pair being positioned in the path of movement of the contact arm and having a notched seat for receiving the contact arm, fuses in said pairs of terminals, means completing a circuit through the fuse which is mounted in the terminal engaged by the contact arm, and means actuated by the blowing of that fuse for forcing the contact arm from the seat in which it is located.

10. The invention as set forth in claim 9, in combination with buifer means on the seat terminals successively engaged by said contact arm to take up the shock due to the movement of said spring-pressed arm into contact with the respective seat terminals.

11. A terminal for a knockout fuse comprisin a pair of spaced side members each terminating at one end in hooks for receiving the trunnions of a knockout fuse assembly, and an end plate joining the opposite ends of said side members, said end plate having one inclined sid'e edge notched out at its junction with thetop edge to provide a seat for receiving a contact arm.

12. The invention as set forth in claim 11, wherein ,the seat on said end plate is approximately midway between the said side members.

GEORGE L. CARLISLE.

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