US2459327A - Automatic reclosing circuit breaker - Google Patents

Description

Jan. 18, 1949. w. D. KYLE, JR., ETAL AUTOMATIC RECLOSING CIRCUIT BREAKER 5 Sheets-Sheet 1 Original Filed June 6, 1941 H770 NEX Jan. 18, 1949. w. D. KYLE, JR., ETAL. 2,459,327

AUTOMATIC RECLOSING CIRCUIT BREAKER Original Filed June 6, 1941 3 Sheets-Sheet 2 IIFI:

Jan. 18, 1,949. w. D. KYLE, JR., ErAL AUTOMATIC RECLOSING CIRCUIT BREAKER 3 Sheets-Shed'l 3 Original Filed June 6, 1941 IIIIH www m f M NWN E V mMJ M@ Y Patented Jan. 18, 1949' AUTOMATIC RECLQSING CIRCUIT BREKER William D. Kyle, J r., Milwaukee, and Carl Schindler, Wauwatosa, Wis., assignors to Line MaterialCompany, a corporation of Delaware original application June s, 1941, serial No. 396,850. Divided and this application July 17,

Objects of this invention are to provide an automatic reclosing circuit breaker in which a fully automatic reclosing circuit breaker is provided which automatically opens upon an electrical overload and automatically closes after a predetermined interval, and which is so constructed that if this opening and reclosing operation occurs a predetermined number of times in rapid succession, the circuit breaker will automatically lock itself in open position, and in which if the opening and reclosing operations occur less than the predetermined number of times, the tripping mechanism will automatically reset itself so that the full predetermined number of operations in rapid succession will be required for any subsequently occurring fault.

Further objects of this invention are to provide an automatic reclosing circuit breaker in which the lock-out mechanism is so arranged as to permanently bias the circuit breaker in open position when the lock-out mechanism operates, which is not dependent upon any pawl, ratchet, or other type of latch which might jar loose if the circuit breaker were subjected to vibration or jarring, or which, when defective for any cause.

would allow the circuit breaker to drop closed, but instead in which the circuit breaker when locked out is biased towards open position and remains in open position irrespective of any jarring or other disturbance that might occur, thereby providing a high factor of safety.

Further objects are to provide an automatic repeating circuit breaker in which manual means are provided for tripping the circuit breaker upon manual operation and for resetting the circuit breaker after it has been locked out, in which this manual resetting means is so made that the circuit breaker can operate independently of such manual resetting means if the fault still persists while the circuit breaker is being manually reset, to thereby guard against any severe mechanical blows or shocks being imparted to the-operator when he is resetting the circuit breaker.

Further objects are to provide a circuit breaker in which the-manual resetting mechanism does not operate for each opening of the circuit breaker but operates only once, moving to the position indicating lock-out when the lock-out occurs, in which the manual reset means is not moved to lock-out position by any blow struck A 1943, Serial No. 495,117

(Cl. 20o-89) by the actuating mechanism of the circuit breaker, but in which it is moved outwardly by a force of a predetermined value 'independently of any violent motion that the circuit breaker may be executing, and in which this manual resetting means and manual opening means is electrically dead at all times.

Further objects are to provide an automatic reclosing circuit breaker in which it is not necessary to use an insulating housing but in which a metal can or housing is provided which is completed by a metal cap, all exposed parts of the apparatus being electrically dead at all times except for two terminal members which are carried by the cap and project from the upper side of the cap, the can being free from any holes or apertures or bushings therethrough and being open only at the top to thereby guard against loss of oil.

Further objects are to provide a reclosing circuit breaker in which all parts of the circuit breaker are carried from a top metal cap, the metal cap being clamped to a metal can containing oil, the construction being such that the circuit breaker may be lifted from the can, if desired, for inspection or repair without removing the can from its mounting, thus facilitating periodic inspection or repair without the necessity of removing the can from the pole or other support upon which it may be mounted, the metal can itself also providing for rapid heat dissipation.

Further objects are to provide an automatic reclosing circuit breaker which cannot be manually held in closed position against an electrical overload, which has a quick break and a quick make no matter in what manner it may be operated, whether by electrical overload or manually, and in which the rapidly moving parts of the circuit breaker are hydraulically cushioned.

An embodiment of the invention is shown in the accompanying drawings, in which:

Figure 1 is a side elevation, partly broken away, of the automatic repeating circuit breaker.

Figure 2 is an enlarged sectional view on the line 2-2 of Figure 1, such view also corresponding to a section on the line 2-2 of Figure 3.

Figure 3 is a sectional view on the line 3--3 of Figure 2.

Figure 4 is a fragmentary sectional view on the line 4 4 of Figure 3.

Figure 5 is a view of the top plate and associated parts with the upper portion of the apparatus'sectioned off.

Figure 6'is a sectional detail of the time delay `means.

'. ner. A convenient way of attaching the top to the can is by means of a pluralityfof bolts 3 which are pivotally mounted between spaced ears 4 ca'rried by the can and which are provided with wing nuts 5.

The wing nutsare adapted tobear against L-shaped clamping plates 6 whose downwardly extending portion is adapted to rest upon the upper face of the ears 4, a suitable lug 1 being provided on 'each of the ears to prevent the clamping plates 3 from sliding on the upper surface of the ears 4. A suitable sealing gasket is positioned between the` flanged upper end of the can and the annular recessed portion of the cover 2, as shown most clearly in Figure 2. Afny suitable attaching means as indicated at 8 and 9 are provided on the can so that the can may be attached to a pole or other suitable support.

, 'I'he cap or cover 2 is provided with a line and load terminal indicated respectively at i0 and and these terminals are carried by insulating'bushings |2, I2.

The automatic recloslng circuit breaker is suspended in its entirety from the'metal cover 2. For example, the metal cover may be provided with a plurality of downwardly extending insulating posts I3 which are secured at their upper ends to the metal cover and which have internally threaded lower portions into which elongated attaching screws i4 pass. These attaching screws hold the upper metal plate i5 and the lower metal plate I6 and the lower insulating annular block or collar II1 in place, the metal plates |5 and i6 being spaced apart by suitable spacers i8 which may be insulating tubes if so desired. The electromagnetic coil or solenoid I9 is positioned between the plates, suitable insulating end pieces being provided, as shown in Figure 2. Centrally of the coil an insulating sleeve or tube 20 is provided.

A non-magnetic operating rod 2I for the cirsuit breaker extends upwardly centrally of the insulating tube 20 and on this rod a plunger 22 formed of magnetic material is freely slidable. This plunger 22 or armature is provided with an enlarged or shouldered lower portion 23 which acts as a piston when passing within the cylincllrical chamber 24 formed in the collar or block The operating rod 2| of the circuit breaker rigidly carries a spider like stop 25 which loosely fits within the sleeve 20 and which serves as an abutment against which the upper end of the magnetic plunger 22 strikes when the coil I9 is energized by an overload current. When this occurs, the plunger 22 is suddenly drawn -upwardly into the coil and strikes the abutment 25, carrying the rod 2| upwardly.

The lower end of the rod 2| is rigidly secured to an insulating cross-head 26. The cross-head 26 carries a pair of contact rods 21 to which are rigidly attached a pair of contact Sleeves. .2.3.

'I'he contact sleeves 28 normally engage the statlonary contact pins 29. 'Ihese stationary con.- tacts or contact pins 29 are connected to the line and load terminals l0 and hereinbefore described. The contact members 21 are connected to opposite sides of the coil I9 by means of ilexible connectors 30 to thus place the coil in series in the circuit through the circuit breaker. It is to be noted from Figure 2 that arcing contacts 3| are lalso provided. Our copending application Serial No. 495,682, led July 22, 1943, which is now Patent No. 2,414,956, issued January 28, 1947, for Electro-magnetic switch, is directed to this contact construction.

Referring to Figures 2 and 3, it will be seen that a rock shaft 32 extends transversely of the cover or cap 2. A rocking sleeve 33 is loosely mounted on this rock-shaft and is provided with a relatively long arm 34 and a relatively shorter arm 35 which constitute, together with the sleeve 33, a unitary member freely rockable upon the shaft 32. The relatively long arm 34 is connected by means of a pair of insulating links 36 with the upper end of the operating rod 2| of the circuit breaker, as shown .most clearly in Figure 2. Thus when the circuit breaker is driven to open position upon the occurrence of an overload, the arm 34 and the arm 35 are rocked upwardly. The arm 5 is connected by means of insulating links 31 with a plunger 38 which is normally positioned within the relatively large portion 39 of the bore of a cylinder d0, see Figure 6.

The cylinder is provided with a relatively smaller upper bore 4| within which a spider like guiding member t2 of the plunger 38 rides. When the arms 36 and 35 are rocked upwardly,

the plunger 38 passes from the relatively large bore 39 into the relatively small bore 5|. However, it is freely drawn. upwardly in the relatively small bore 6| as the spring pressed valve 33 yields and allows oil to pass downwardly through apertures 3B into the space below the plunger and no material retardation occurs, thereby allowing the circuit breaker to open with a very quick stroke.

However, after the circuit breaker has opened, it cannot immediately close for there is a time delay produced by the downward travel of the plunger 38 through the relatively small bore or constricted bore 4| the oil leaking out around the sides of the plunger 38 and retarding the downward motion of the circuit breaker. However, as the circuit breaker approaches closed position, the plunger 33 rides out of the constricted passage 4| into the larger passage 39 of the cylinder 40 and the circuit breaker completes its closing stroke with a quick motion.

It is of course-obvious that a'small passage could be provided beneath the piston 38 through the wall of the cylinder or else through the piston itself to provide for the escape of oil or, as stated hereinabove, the oil may leak around between the piston and the cylinder. Thus a predetermined time delay is imposed upon the circuit breaker after it has opened to thereby provide an interval of time before it will close so that if the fault is only a temporary fault, the circuit breaker will stay closed after it has once opened. If the fault persists, it is obvious that the circuit breaker will again make a quick opening stroke and will also be retarded on its closing stroke.

Itis desirable to provide means for permanently locking the circuit breaker in open position after a predetermined number of rapidly succeeding This is readily accomplished by providlng a. tripping means actuated by oil pumped by the circuit breaker upon operation. As shown in Figure 2, the collar or head I1 is provided with a cylinder like aperture 24 within which the piston or enlarged shouldered portion 23 of the plunger 22 passes during the completion of the upward stroke of the plunger. This also provides a hydraulic cushion for the plunger and thus materially reduces wear. The oil from the chamber 24 passes through a port 45 past a check valve 46 into the lower end of the cylinder 41, see Figure 2. 1

A piston 48 is positioned'within this cylinder and is moved up a predetermined distance on each opening stroke of the plunger 22,. The check valve seats and prevents the return of the oil from the bottom of the cylinder. The piston or 'head '23 of the plunger 22 freelv passes from the cylinder 24 as a relief check valve 49'is providedto allow oil to pass back into the cylinder 24 above the piston '23.

- It is obvious that after a certain number of operations, the piston 48 of the tripping device will move upwardly a suillcient distance to project the pin 50 carried thereby through an opening 5I 'f in the top plate I5 and against the` trip latch 52, thereby raising the trip latch. This raising of the vtrip latch, as will be described hereinafter, releases the lock-out mechanism and locks the circuit breaker in open position. However, it is desirable to have this lock-out of the circuit breakeroccur not only when there has been a predetermined number of operations of the circuit breaker, but also only when these operations occur in rapid succession. f

If, for the purpose of illustration, it is assumed that the circuit breaker is to lock open after three operations in quick succession, it obviously is not desirable for the circuit breaker to lock openafter two operations occurring in quick, sucy cession and a third operation occurring at a very much later time. This result is accomplished by providing an adjustable leak, not shown, from the cylinder 41 at a point beneath the piston 48. The features oi' this last described structure are set forth and claimed in our copending application hereinabove identified of which this is a division. The purpose of this construction is to accomplish the following results: If, for example, less than the predetermined number of quickly succeeding operations has occurred, the piston 48 will settle downwardly as the oil flows through the leak passage and will nally come to rest at the bottom part of its stroke, as shown in Figure 2. thereby resetting the tripping .mechanism to its initial position.

This feature is of particular importan-ce for if the circuit breaker performs one or two operations and the fault clears, the circuit breaker still will have its full number of times for a sequential rapid operation in the event any subsequent fault occurs.

Returning to the latching and tripping mechanism with particular reference to Figures 2 and 4, it will be seen that the latchinf.r lever is provided with a latcbing portion 53 beneath which a latching plate 54 is normally held, the latching plate 54 being of metal and being carried by an insulatinar lever 55. The lever 55 is rigidly bolted to a metal lever 56. which latter is rigid with a sleeve 51. A second lever 58 is also rigid with the sleeve 51 and is spring urged in a counterclockwise direction by means of a spring 59. This spring 59 has its upper end attached at a fixed point within the cap 2, as shown in Figure 2. Therefore, it will be seen that the latch lever is permanently biased towards its uppermost position which will be shown as the descriptionproceeds to be the lock-out position for the circuit breaker.Y y

The lever 56, as will be seen from Figures 2 and 3, is provided with a head or pin positioned directly beneath the lever 34, which'latter lever is attached by means of the links 36 with the operating rod 2|' of the circuit breaker. Therefore it is apparent that when the trip latch 52 is released, that the circuit breaker will be locked open as the spring 59 will cause the lever 56 with the projection 60 to rock in a counterclockwise direction, see Figure 2, and thus hold the circuit breaker locked open. The circuit breaker will thus be permanently biased towards open position when it is locked out and will not be dependent upon anypawl or any other type of latch of this order which might jar loose and allow the circuitbreaker to drop to closed position.

This contingency isavoided by providing the without causing operation of thelclrcuit breaker.'

This is prevented by providing thermal means responsive to the temperature of the oil within the .tank I for operating the trip latch 52. As may be seen from reference to Figures 3 and 5, a bimetallic folded strip 6I is carried'by the upper plate I5 and has its free end positioned beneath the trip latch 52 so that when the bimetallic strip 6I opens up as the oil becomes abnormally heated, it will raise the trip latch 52 and release the trip lever 55. thereby causing a, quick opening of the circuit breaker under the iniluence of the spring 59 and lock-out of the circuit breaker. This thermal release is the subject matter of our copending application Serial No. 495,118, filed July 17, 1943, which is now Patent No. 2,455,667, issued November1 30,1948, for Automatic reclosing circuit breakers. l

Manual means are also provided for opening the circuit breaker with a quick opening stroke. The manual operating means consists of an eyeleted lever 62, see Figures 3 and 7, which is positioned within a, hood 63 integral with the cap 2. The hood is open at its lower side and is provided with a cut out portion 64 so that the hook of a switch stick may be inserted in the eye of the lever 62 and the lever may be drawn downwardly to cause a quick opening of the circuit breaker in a manner hereinafter to appear, or to move the lever upwardly back to the position shown in Figure 7 to reset the circuit breaker.

The lever 62 is rigidly attached to the shaft 32 and the shaft 32 rigidly carries a reset lever 65 and an eccentric 66. The eccentric 66 is shown most clearly in Figures 3 and 4. The sleeve 51, see Figures 3 and 4. is loosely mounted on the eccentric 66 and is free to rock about such eccentric independently of any action of the eccentric. However, when the lever 62 is pulled downwardly, the eccentric 66 draws the latch lever 55 upwardly in a slanting direction towards the left as viewed in Figure 4, and thus withdraws the latch plate 54 from the latch portion 53 of the latch lever l2. The spring I9 is now free to act and causes a quick counterclockwise stroke of the lever 56 whose pin or projecting portion B0 strikes the lever 34 and opens the circuit breaker with a quick opening stroke. The circuit breaker will now be permanently locked open until it is manually reset.

The resetting is accomplished through the medium of the lever 82, the shaft 32 and the reset lever 05, see Figures 3, 8 and 9. The reset lever 85 is positioned above a Din or projection 61 rigid with the latching lever 55, as shown most clearly in Figure 8, the projection 81 being shown in dotted lin in Figure 3. It is clear that when the lever C is rocked in a clockwise direction back to its posi on shown in Figure 7, that the reset lever l will engage the pin 81 and will force the latching lever 58 downwardly against the action of the spring Il to its normal position as shown in Figure 2,V thus resetting the circuit breaker. The circuit breaker will thereafter close after a suitable interval determined bythe time delay mechanism shown in Figure 6 and hereinabove described.

It is to be noted that a relatively light spring 68 is secured lto the reset lever 55 and to a pin S9 carried by the lever 58. The spring t8 is relatively light as compared to the spring 59 and serves merely to hold the lever 62, see Figures 3 and "l, in its uppermost position until the lever 62 has been rocked downwardly when the circuit breaker is locked out.

It is to be noted that the lever 62 does not move downwardly for each operation of the circuit breaker but only moves downwardly when the lock-out mechanism functions or when the lever $2 is manually pulled downwardly for manual operation of the circuit breaker.

It is to be noted particularly that in the resetting operation, the lineman or operator is never subjected to any violent shock even though the fault may still persist when the circuit breaker is reset. When the circuit breaker is reset and the fault still persists, the circuit breaker will instantly move to full open position but nevertheless the lever 3B, see Figure 2, will move upwardly away from the projection @Il of the lever 56 and consequently no blow or jar will be imparted to the operator. The only force opposing the resetting is the spring 59 and the force due to the opening stroke of the circuit breaker is not imparted to the resetting and manual release lever 62.

Another feature to be noted is that in the event the circuit breaker is closed and it is desired to' manually open it, no matter how slowly the operator pulls downwardly on the lever 62 by means of a switch stick, for instance. as soon as the latch lever 55, see Figure 2, is withdrawn from the llatch member 52, the circuit breaker will execute a quick opening vstroke due to the action of the spring 59 hereinbefore described.

'Ihus the circuit breaker always has a quick opening stroke no matter whether it is released manually or automatically. It also has a quick closing stroke after a certain interval provided by the time delay mechanism as the final closing stroke of the circuit breaker is unimpeded as hereinabove described.

It is preferable to encase the lower portion of the circuit breaker, that is to say, the stationary and movable contacts, within an insulating cylindrical sleeve 10. The upper end of the sleeve 10 is closed,V except for the passageways hereinbefore described, by means of the collar or member Il and the lower end of the sleeve 10 is closed by means of the base member ll. This base member is provided with an oil inlet aperture 12, see Figure 2, which is normally closed by a downwardly seating nap valve 13.

It is preferable to provide insulating baille members such as indicated by the reference character 14 between the stationary contacts. This structure forms no'portion of the present invention and is more clearly set forth in our copending application Serial No. 534,574, illed May 8, 1944, for Automatic reclosing circuit breakers, which is now Patent No. 2,392,483 issued January 8. 1946.

By having the lower portion or active. contacts of the circuit breaker enclosed by the sleeve 10 and base portion 'Il and upper collar or member' I1, see Figure 2, it is apparent that under violent overload where a considerable amount of gas is generated, that the tripping plunger 48 will be driven to its uppermost position and willtrip the lock-out mechanism and thereby lock the circuit breaker in open position so that a succeeding violent action of the circuit breaker will not be permitted even if the fault persists.

This is a very unusual condition but the construction of this device is such that it will care for this abnormal condition and will save the circuit breaker from the necessity of executing the required number of operations in rapid sequence under an extremely heavy abnormal overload.

. This invention is designed to take care of still another abnormal condition where an overload of too small a value occurs to cause complete operation of the circuit breaker at one stroke, but nevertheless might cause apartial opening followed by quick -reclosing. of the circuit breaker without having the circuit breaker execute a complete opening stroke. It is obvious that the repeated breaking will result in the generation of gas and the gas so generated will force oil into the cylinder el, thereby driving the tripping plunger i8 upwardly, thus tripping the lock-out mechanism.

Although this invention has been described in considerable detaib it is to be understood that such description is intended as illustrative rather than limiting, as the invention may be variously embodied and is to be interpreted as claimed.

We claim:

1. In a device of the class described, an electric switch normally biased towards closed position, normally inactive lock-out means for moving said switch to open position and for locking said switch in open position, biasing means biasing said lock-out means towards switch open position, a latch, said lock-out means having a latching lever normally engaged by said latch for restraining said lock-out means, automatic means for moving said latch to release said latching lever. and manual means for moving said latching lever with reference to said latch to release said latching lever while said latch remains stationary.

2. In a device of the class described, an electric switch normally biased towards closed position, normally inactive lock-out means for moving said switch to open position and for locking said switch in open position, biasing means biasing said lock-out means towards switch open position, a latch, said lock-out means having a latching lever normally engaged by said latch for .restraining said lock-out means, automatic means for moving said latch to release said latching lever, and manual means for moving said 9 ,i latching lever approximately longitudinally away from said latch to release said latching lever while said latch remains stationary.

3. In a device of the class described, an electric switch normally biased towards closed position, normally inactive lock-out means for moving said switch to open position and for locking said switch in open position, biasing means biasing said lock-out means towards switch open position, a latch, said lock-out means having a latching lever normally engaged by said latch for restraining said lock-out means, automatic means for moving said latch to release said latching lever, manual means for moving said Ylatching lever approximately longitudinally away from said latch to release said latching lever when said manual means is moved in one direction and while said latch remains stationary, and means operatively connected to said manual means for engaging said lock-out means and for resetting said lock-out means when said manual means is moved in the reverse direction.

4. In a circuit breaker an electric switch normally biased towards closed position, overload means for moving said switch to open position upon the occurrence of an overload, normally inactive lock-out means for moving said switch to open position and for locking said switch in open position, a single manual means for releasing said lock-out means by longitudinal motion thereof for opening said switch, and biasing means for biasing said lock-out means towards switch open position, said manual means being operative to move said lock-out means laterally to its inactive position to permit closing of said switch.

5. In a circuit breaker an electric switch nor-v mally biased towards closed position, overload means for opening said switch upon the occurrence of an overload, normally latched lock-out means for moving said switch to open position and for locking said switch in open position, biasing means biasing said lockout means towards open position, and manual means for releasing said lock-out means for opening said switch through the agency of said lock-out means when said manual means is moved in one direction, said switch when actuated by said lock-out means having a quick opening stroke, said manual means being operative to move said lock-out means to its latched position to permit closing of said switch when said manual means is moved in the reverse direction.

6. In a circuit breaker an electric switch normally biased towards closed position, overload means for opening said switch upon the occurrence o! an overload. a movably mounted catch, normally inactive lock-out means for moving said cluding a latch lever normally engaged by saidl catch, biasing means biasing said lock-out means towards switch open position, automatic means for moving-said catch to release said latch lever, an eccentric member, said 1ock-out means being switch to open position and for locking said switch in open'position, said lock-out means including a latch lever normally engaged by said catch, biasing means biasing said lock-out means towards switch open position, automatic means for moving said catch to release said latch lever, an eccentric' member, said lock-out means being pivotally mounted on said eccentric member and when released from said catch rocking about said eccentric member to switch open position. and manual means for rotating said eccentric member to withdraw said latch lever from ,engagement with said catch by motion of said latch lever in a direction away from said catch.

pivotally mounted on said eccentric member and when released from said catch rocking about said eccentric member to switch open` position, and manual means for rotating said eccentric member to withdraw said latch lever from engagement with said catch by motion of said latch lever in a. direction away from catch when said manual means is rocked in-one direction, said manualmeans when rocked in the reverse direc'- tion being operative to move said lock-out means to its latched position to permit closing ot said switzh.

8. In a circuit breaker Ian .electric switch normally biased towards closed position, overload means for opening said switch upon the occurrence of an overload, a movably mounted catch, normally inactive lock-out means for moving said switch to open position and for locking said switch in open position, said lock-out means including a latch lever normally engaged by said catch, biasing means biasing said lock-out means towards switch open position, automatic means for moving said catch to release said latch lever, an eccentric member, said lock-out means being pivotally mounted on said eccentric member and when released lfrom said catch rocking about said eccentric member to switch open position, manual means for rotating said eccentric member to withdraw said latch lever irom engagement with said catch by motion of said latch lever in a direction away from said catch when said manual means is rocked in one direction, said manual means when rocked in the reverse direction being operative to move said lock-out means to its latched position to permit closing of said switch, andtime delay means for delaying the initial portion of the closing stroke of said switch,

said switch having a quick iinal closing stroke.

WILLIAM D. KYLE, Jn. CARL BCHINDLER.

REFERENCES CITED The following references are of record in the ille oi' this patent:

UNITED STATES PATENTS Number 2 2,066 Grady May 13, 1941 FOREIGN PATENTS Country Number Date Switzerland Sept. 2, 1885 Mayer Nov. 8, 1982

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