US1909234A - Circuit breaker - Google Patents

Description

y 16, 1933- s. J. SPURGEON ET AL 1,909,234

CIRCUIT BREAKER Filed May 22, 1928 2 Sheets-Sheet l INVENTORS 45 SAMUEL J. SPURGEON HARRY H. KNOWLES GEORGE N.LEMMON i 272627 a Ziarnqys MMM Patented May 16, 1933 FFIQE SAMUEL J. SPUBGEON, HARRY H. KNOWLES, M'D GEORGE ill. ELMLTIMN, OF BIRMINGHW, ALABAMA; SAID KNOWLES AND SAID LEMMQN ASSIEGl-NGRS TCO) SQ'UTHERN STATES EQUIPMENT COMPANY, OF BIRMINGHAM, A CUEPDEATItlN 01H rumours ar A run llhis invention relates to circuit breakers and more particularly to breakers of the type used on high tension transmission lines to open the circuit when the line current exceeds the normal safe amount.

Circuit breakers for this general purpose are lmown. A common construction has been a breaker of the fuse type in which a conducting element having a lower temperature oi fusion than the ordinary line conductor is in terposed in the line. Upon increase of temperature, due to excess current, this element fuses and interrupts the circuit. The disadvantage of such fuses is that, for heavy currents, they are not uniform in action. lit is a matter of (lifiiculty if not of impossibility to install a number of such fuses in a line and have it certain that all will operate upon attainment of the same excess current. Uni- :forniity of operation is, however, very essential.

Another type in use is the oil circuit breaker which is solenoid operated. llhis type gives desirable uniformity of operation but is expensive and requires attention after it is installed to make certain that it is in operable condition.

.lt is an object of this invention to provide a circuit breaker that will involve only operations which may be definitely predetermined by virtue of which uniformity of operation of all such units on a line may be assured.

A further object is to provide a circuit breaker that will function independently oi the temperature or the conductor interrupting elements.

In attaining these objects, it is also the purpose to provide a structure which will be mechanically ethcient because oil simple, rugged construction and which will be cilicient as a circuit breaker in providing a quick break and in separating the conducting parts to prevent continual arcing.

Finally it is an object to improve the construction of certain elements, and, in particular, that of a frangible conductor by making it readily frangible without impairing its conducting properties.

The present preferred embodiment of the invention is described hereinafter road is it 'lustrated in the accompanying drawings.

in the drawings:

Fig. 1 is an assembly view of the circuit breaker;

Fig. 2 is a view of a frangible conductor;

Fig. 3 is a detail view of a portion of the frangible conductor of IF ig. 2;

Fig. 4; is a view in elevation of part oi the operating mechanism;

I Fig. 5 is a plan View showing the operating mecnamsm; and

Fig. (3 shows a detail in elevation.

The base 1 is adapted to be mounted on a pole or other line conductor support and carries insulators i2, 2 which have tops 3, 3' of conducting material, to which the circuit breaker apparatus is attached.

On the top 3 is a conducting plate l to which the line conductor 6 is attached in any of the usual ways. Top 3 carries a conducting frame 5 and the operating mechanism, hereinafter described, for the circuit breaker. The frame 5 carries an insulator 1% which supports a terminal connection for the line conductor 7, The line conductors 6, 'Z and the parts in connection therewith are connected by a frangible conductor 9, housed in an insulating tube 8, which normally bridges the space between the mechanisms carried by the two insulators. I

@ne end of the conductor 9 is looped over one leg of a rocker 16, the other leg of which is pivoted at 17 on the plate l. A spring 18 urges the rocker about its pivot 17 and places a tension on conductor 9.

The opposite end of the insulating tube is secured in a socket (Fig. 5) which has a trunnion 20 pivoted in a portion of the casing 13 and extending into a bracket 13 bolted to the frame 5. A. torsion spring 24 has one end engaged in the fixed bracket 13 and the other end engaged in a part ot a collar 20 fixedly secured on the end at the trunnion 20, thus tending to rotate socket it) about the trunnion axis and swing tube 8 upward.

Conductor 9, at this end, has a loop lying over the upper end of a crank 19 pivoted on a shaft 25 which is supported in a boss on the casing 13. The crank 19 also has a portion 19 engaging a catch 26 which is pivoted at 27 on the end of socket 10 (see Figs. 5 and 6). This latch prevents turning of socket 10 and tube 8 under the effort of spring 24 as long as the crank 19 is in the normal position shown.

The operating mechanism for the shaft 25 and crank 19 is shown in F i re 4 as being within the housing 13. Sha t 25 has keyed to it a bell crank member 28 which is connected to an actuating device by a link 29. The actuating device consists of a crank 30 mounted on a fixed shaft 30 extending from the wall of casing 13. A drum 33 houses this mechanism and is secured to casing 13 by screws 35. Within drum 33- is a coil spring 31, shown only in partial length in Fig. 4, one end of which is attached to the fixed drum at 34 and the other end of which is fixed to crank 30. The spring is under tension and tends to rotate crank 30 in the direction of the arrow. This would swing crank 28 and turn shaft 25 were it not for a latch or locking member 37 which is pivoted at 37' to casing 13 and has a recess engaging the roller 36 on the crank 28. The latch 37 normally is held in the position shown by a second latch 38, likewise pivoted on the casing wall. One arm of this latch 38 engages a shoulder on latch 37 while the other arm, at right angles, extends over thepin 39 of solenoid 42. It is noted that the thrust of member 37 against the arm of latch 38 is radially toward the pivot so that there is no tendency to turn latch 38 about the pivot.

The solenoid 42 is mounted in the casing. Its coil is in parallel with the line throu h conductors 15 and 43. The armature of e solenoid normally rests below pin 39. Preferably a dash t is associated with the armature 40. This is shown as comprising a cylinder 48 having therein a free piston 49. and a body of oil, the piston 49 being connected to or integral with armature 40.

The conductor 9 is shown in Fi res 2 and 3. It is made up of two flexi le elements having each a 100 d end, the two being connected by a rigi member 46. The central portion of 46 is turned down as shown so that the remaining section is of low tensile strength. The groove has a filler of lead or other conducting material, preferably of low tensile strength, the whole section providing a path, of the same conductive cross-section as the ori 'nal section of member 46, but mechanical y weak. By reason of this construction the area that is effective for conduction of current is unchanged but there is a reduced cross-area effective for affording material tensile stren h. Thus the frangibility is increased wit out changin serious ly the conducting characteristic or diminishin the corona protection.

pon creation of excess current in the line by overload, li htning discharge, or other electrical distur ance, coil 42 1s energized sufliciently to lift armature until it strikes pin 39 and causes latch 38 to swing free of latch 37. The force of spring 31 acting on crank 28 now swings crank 28 since roller 36, acting against the wall of its recess in latch 37, lifts the latter. Crank 28 assumes the position shown in dotted lines (Fig. 4). This swings crank 19 suddenly, and the suddenly applied force causes the breakage of the conductor 9 and at the same time releases latch 26. Since the conductor is under considerable stress when it breaks, the ends are jerked outwardly of the tube under the action of both spring 18 and spring 31. An arc is established, of courseyu'pon rupture of the conductor 9 and there is the known phenomenon of the expulsion of the ends of the conductor from the tube, and the extinguishment of the arc. The end of conductor 9 at the left in Figure 1 is caught by the receiver 50 the open end whereof faces the end of the tube 8 which contains the frangible conductor. The spring 24 swings tube 8 upwardly to the position shown in dotted lines in Fig. 1. The arcing horns 11, 12 supplement the expulsion tube, in case of emergency, in extinguishing the arc.

Immediately upon the breaking of the conductor an arc is formed but it is instantly extinguished by the' expulsion of the fragment of the conductor 9 into the receiver 50. In most'cases the extinction occurs before the tube 8 swings upwardly.

There do arise, however, conditions which make it advisable to provide supplementary means for extinguishing the arc. In the present instance, the swingin of the tube 8 with the other fragment 0% conductor 9 removes another possible arcing terminal and affords an indication that the conductor has been broken. In addition, arcing horns 11', 12 of known type are provided to carry the arc upward and to draw it out until it breaks.

It is evident that by this structure the current is effectively interrupted and the broken conductor parts are completely removed from the apparatus. A permanent gap is created since tube 8 remains up until manually returned and supplied with a new conductor and until the latch mechanisms are reset.

The operation is independent of the temperature in the conductor. It depends only upon mechanisms whose functions are easily predetermined. Thus, the current necessary to lift an armature against the force of the dash pot is easily found. Conversely, to suit the operation to a given current, the size of the coil and of the dash pot are determinable definitely. and the removal of the expulsion tube are accomplished by springs which may be as The breaking of the conductor powerful as necemary, thus making speedy and certain operation an easy matter.

, Various modifications of the structure disclosed are possible, all involving the inventive concepts stated in the following claims.

We claim:

v 1.'In a circuit breaker, a frangible conductor, an insulating container therefor means for swinging said container out of normal position, means for breaking said conductor, and a common means for controlling the operation of said swinging and said breaking means.

2. In a circuit breaker, 'a frangible conductor, "an insulating container therefor, means for swinging said container out of normal position, means for breaking said conductor, and a common means for initiating the operation of said swinging and said breaking means.

'3. In a circuit breaker, a frangible conductor, an insulating container therefor means for swinging said container out of normal position, means for breaking said conductor, and solenoid operated means for initiating the operation of saidswinging and said breakin means.

4. A circu1t breaker comprising a frangible conductor and an insulating container therefor in combination with a mechanism operative upon overload in the circuit for applying a mechanical force to said conductor to break it and for moving said container out of its normal position.

5. In a circuit breaker, a frangible conductor and means for applying a mechanical force to said conductor to break the same upon overload in the circuit, said conductor having a weakened section of reduced cross area with a filler of conducting material of low tensile strength.

6. In a circuit breaker, a frangible conductor and means for applying a mechanical force to said conductor to break the same upon overload in the circuit, said conductor having a weakened section of reduced cross area with a filler at the reduced section inwithout materially increasing the tensile strength at the section.

7. In a circuit breaker, a tubular insulating container pivotally mounted and movable toward open circuit and closed circuit positions, a conductor in said container, means responsive to overload conditions in the circuit to open the circuit within the con tainer by mechanical force and immediately thereafter to remove the container from its closed circuit position.

8. In a circuit breaker, a continuous unbroken insulating tube, a flexible conductor within the tube forming part of a circuit, mechanical means for opening the circuit within the tube and solenoid means for initiating the operation of the said mechanical means.

9. In a circuit breaker,.a continuous unbroken insulating tubehingedly mounted at one end and movable between open and closed osition, a flexible conductor within the tube orming part of a circuit, mechanical means for opening the circuit within the tube, and solenoid means for initiating the operation of the mechanical means.

10. In an air break circuit breaker, two gap-spaced insulators with conducting terminals thereon, a tubular insulating container spanning the gap, a flexible conductor within the container and means to open the circuit through the container, to ether with means independent and removed rom one of the said insulators to catch parts of the said flexible conductor when forcibly expelled from the container.

11. In a circuit breaker, two gap-spaced insulated supports, a tubular insulatin container hingedly mounted upon one 0 said supports and movable into and out of gapspanning position, a flexible conductor within the container and means to open the circuit through the container, together with means independent and removed from one of the said insulators to catch parts of the said flexible conductor when forcibly expelled from the container.

In testimony whereof we have signed our. names to this s ecification.

S MUEL J. SPURGEON. HARRY H. KNOWLES. GEORGE N. LEMMON.

' creasing the effective conductive area but

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