US2264990A - Control mechanism for circuit breaker operating motors - Google Patents

Description

Dec. 2, 1941. T. I INDs'rRoM ETAL 2,264,990

CONTROL MECHANISM FOR CIRCUIT BREAKER OPERATING MOTORS Filed June 28, 1940 INVENTORS T/*e fha/from and fla/'Ome 50000)?.

BYE122 ATTORNEY Patented Dec. 2, 1941 CONTROL MECHANISM FOB CIRCUIT BREAKER OPERATING MOTORS Ture Lindstrom, Edgewood, and Jerome Sandin, Forest Hills, Pa., asaignors to Westinghouse Electric a Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania `Application June 28, 1940, Serial No. 342,886

1i cam Our invention relates to automatic operatingmechanisms for both opening and closing the operating-mechanisms of circuit breakers, or for performing either the opening operation or the closing operation.

Although our invention, in its broadest aspects, is not limited to any particular use or application, the present invention was primarily designed for the operation of air-type circuitbreakers.

One of the objects of our invention is to utilize an ordinary four-position snap-switch, or an adaptation thereof, for the control of a motor which continuously turns a shaft in the same direction a half-revolution at a time, the motor being automatically cut off at the end of each half-revolution, and the snap-switch being operated twice, during said half-revolution, and being so connected as to flnally deenergize the motor.

A further object of our invention is to provide means which is responsive to a non-motor-operated tripping-operation of the circuit-breaker, for automatically effecting an opening operation of the motor-control mechanism, in order that the motor-control mechanism shall be in a position ready for a circuit-breaker closing-operation without necessitating an actuation of the manual control-switch to the open position for the purpose of resetting" the breaker, before the breaker can be closed.

With the foregoing and other objects in view, our invention consists in the apparatus, combination, circuits, and methods hereinafter described `and claimed, and illustrated in the accompanying drawing, wherein:

Figure 1 is a somewhat simplified and some- 4 what diagrammatic side-elevational view of a, circuit-breaker including our motor-actuated operating-mechanism, with parts broken away and parts in section to better illustrate the construction; and

Fig. 2 is a diagrammatic view of circuits and apparatus illustrating our motor-control circuits.

Our invention is illustrated as being applied for the operation of an air-break circuit-controlling device orcircuit-breaker 5 which is of the type shown and claimed in Lindstrom Patents Nos. 2,083,304 and 2,186,251 granted June 8, 1937, and January 9, 1940, and in a Sandin Patent No. 2,043,306, granted June9, .1936, although, in the broader aspects of our invention, such circuitbreaker illustration may be regarded simply as typical of any circuit breaker having a stationary main contact 6, a movable main contact 1 carried by a movable arm 8 pivoted at 9, an operat- (CL F75- 294) ing-lever 2| is in cooperative position with re-v spect to the tripping-mechanism I 2, which includes a latching-device 23 which is released by a trip-bar 24 which is actuated by a U-shaped single-turn magnetic circuit 25, encircling one of the leads 26 of the circuit-breaker, and attracting an armature 21, so as to be responsive, on predetermined over-currents, to trip the circuitbreaker. A thermally responsive bimetallic tripdevice 28 is also shown.

Our invention particularly relates to the mechanism which is utilized to open and close the operating-arm i2 of such a circuit-breaker, or of any other circuit-breaker. Certain aspects of our invention, as illustrated, are byk way of improvement over the motor-driven operating-mechanism which is described and claimed in an application of Leon R. Ludwig and Ture Lindstrom, Serial No. 168,204, led October 9, 1937, Patent No. 2,228,466, granted January 14, 1941, and assigned to the Westinghouse Electric & Manufacturing Company. The illustrated motor-mechanism consists of a motor 30, the shaft of which carries a worm gear. Il which drives a wenn wheel 32 which is mounted on a slow-speed shaft 33 carrying a. crank-arm 34, or'suitable equivalent mechanism for actuating, or imparting operating-thrusts to, an extension 35 which is attached to the circuit-breaker operating-arm I3.

With a motor-mechanism of such a type, the motor 30 always turns in the same direction, both during the circuit-breaker closing-operation and during the circuit-breaker opening-operation, the crankshaft 33 turning one-half of a revolution for each operation.

The particular novel features of our invention relate to the control-means for a motor-mechanismof the type just described. In accordance with our invention, we mount a 4-position snapswltch 31 in operative relation to the crankshaft 33, so as to be actuated thereby. The snapswitch 31 is provided with four stationary contacts, A, B, C and D, disposed at 90-degree in- Il tervals, and a 90-degree rotating-contact R. which the B-i-C position, and thence, in successive operations, to the C-D position,` to the D-A position, and back to th'e A-B position, turning, with sudden snap-actions, in response to the slow, steady movement of the crankshaft I3.

In accordance with our invention, we also equip the circuit-breaker operating-mechanism` Il with a suitable type of auxiliary switch 45 which is very diagrammatically indicated as being open4 when the circuit-breaker is closed and closed when the circuit-breaker is open.

The control-circuit of our motor 50 also includes a three-position, manually operated switch 4i having three stationary contacts 42, 43 and 44 which are disposed in operative relation to a movable contact-arm 45 which is biased to its central position by a suitable spring-means which is diagrammatically indicated at 45-41.

The motor-operating circuits are so arranged that one terminal 50 of the motor is connected to one line-terminal, while the -other motor-terminal 5i -is connected to two diametrically opposite stationary contacts A and C of the snapswitch 31. 'Ihe stationary contactB of the snapswitch is connected, by a conductor 52, to th'e right-hand stationary contact 44 of the manual switch 4i. The aforesaid stationary contact B of the snap-switch 31 is also connected, through contact-arm 4'5 of the manual switch 4I is conaas-.aoco

,cordingly automatically stopped by the crankshaft operated snap-switch l1. The manual switch-arm `45 may now be released, whereupon it will .automatically return to its mid-position under the influence of the centering-spring 44.

During this opening-movement of the operat-l ing-mechanism il the operating-lever i3 is moved downwardly. In the initial portion of this downward movement of the operating-lever Il, the spring-biased toggle I4I 5 is broken, so that the movable contact-arm 5 of the breaker opens, with a sudden snap-action, without waiting for the slower-movingparts of the operating-mech anism Il. completes its opening-operation, the ybreaker au- When the operating-mechanism Il tomatically "resets, so that the tonie-link I4I5 and the operating-lever Il again become tied together, ready for a closing-operation. Y

The circuit-breaker 5 and the motor-mechanism are now in their open positions. If it ls desired, now, to close the circuit-breaker 5, the manual controiswitch is moved to the left, whereupon the switch-arm 45 connects the lineterminal 55 lto the contact 42, which is joined to the contact D by the conductor 55. Since the mechanism-operated snap-switch is now in the position C-D, a motor-energizing circuit will 'oe completed from the contact D, through the snapswitch arm R, to the contact C, and thence' through the conductor 5i to the motor 30. The motor thereupon operates again, turning in the same direction'as before, and swinging vthe nected, by a conductor 55, to the other lineterminal.

In operation, when the circuit-breaker 5 is closed, and it is desired to open the same, the manual control-switch 4I is moved to the right,

so as to cause the movable switch-arm 45 to connect the line-terminal 55 to the contact 44.V

This switch-operation completes the motor-circuit from the said contact 44, through the con# cluctorl 52, the contact B, the crankshaft-operated bellcrank-shaped switch-arm R, thecontact I A, and the conductor 5i, tu the motor 30 and thence to the other line-terminal 50. 'Ihe motor then turns. slowly driving the crankshaft Il, which is indicated in dotted lines in Fig. 2. As the crankshaft turns, the crank 34 moves the handle-extension 35 downwardly, or in a direc-J tion necessary for opening the circuit-breaker 5. When the crankshaft has rotated approximately a quarter of a revolution, or 90, the snapswitch 31 suddenly moves its contact-arm R. through 90, thus connecting thecontact B to the contact C, instead of being connected to the: contact A. Since the contacts A and C are electrically connected through the conductor 5|, the motor 30 remains energized without any notice' able break in its energization when th'e crankshaft-operated snap-switch suddenly changes from the position A--B to the position B-C.

crank 34 around so that it now moves upwardly in a closing direction, carrying the handle-extension 35 upwardly with it, so as to begin to close the breaker. When .the crankshaft has made about half of its closing movement, or a quarterturn, the snap-switch suddenly changes from its position C-D to its position D-A, and the motor continues to be energized because the contact D is now joined to the contact A, 4which is. in turn, connected to the motor-lead 5I. At the completion of the 180 closing-movement of the motor-mechanism, the snap-switch returns to its initial position A-B, and the breaker-closing circuit of `the motor is deenergized. The manual `switch '4i may now be released, whereupon it returns to its central position through the action of its center-spring 41.

In case the circuit-breaker 5 should move automatically to its open position, as by an overload response of the tripping-mechanism l2, independently of the motor-mechanism, it is very de- When'the crankshaft has completed approxii mately a half-rotation, or a movement, the circuit-breaker 5 and its operating-mechanism Il will be in their open positions, and th'e fourposition snap-switch will be again 'suddenly actuated, to change from its position B-C to the position C-D. The conductors 5| and 52 are now no longer connected by thevrotatable or snapping switch-arm R, and the motor is acsirable for the motor-mechanism to be automatically actuated to its open position in order to reset the breaker so that'it will be ready for a closing-operation in response to a single movement of the manual switch-arm 45. To this end. the self-centering function of our manual switch 4| comes into play, in conjunction with the auxiliary switch 40 which is closed when the circuit breaker opens. When the circuit-breaker is tripped open, the opening movement of the breaker-arm 8 closes the auxiliary switch 40, which thereupon completes a motor-energizing circuit which can be traced from the line-terminal 50, through the motor 30, to the conductor 5i, the snap-switch contacts A-B, the conductors 52 and 53, the auxiliary switch 40, the contact 43, the centrally positioned switch-arm 45,"and the other line-terminal 56. The motor thereupon goes through with a 180 opening-movement, as

previously described. until the snap-switch 31 moves to the position CD, whereupon the motor is deenergized, and the mechanism is in a posiasumo tion ready for another breaker-closing operation whenever the operator or station-attendant shall move the manual control-switch to the left.

The provision of a three-position manual switch Il, and the utilization of the central position l! to complete the opening-circuit of the auxiliary switch 40 provides an effective antipumping system, making it unnecessary to resort to special auxiliary switches for this purpose, as in many previous breakers. Thus.if the manual switch Il is moved to its close" position |2,and held there for a while after the breaker is closed, if the breaker immediately trips open, on its automatic control, as by overload-operation, for example, the breaker will not reclose until the handle or movable switch-arm 46 is released, because the central switch c'ontact Il is in series with thel resetting switch 4l. Thus, there can be no pumping action, or repeated closings of the breaker in response to a single closing-operation of the manual switch 4I.

While we have shown our breaker-operating mechanism applied to a single form of circuitbreaker, and while we have shown a single form of motor-controlling means therefor, we wish it to be understood that such showing, and the accompanying description, are only by way of illustration and explanation, and that our invention, in its broader aspects, is susceptible of other applications or uses, and other embodiments as to specific circuits and apparatus. We desire, therefore, that our appended claims shall be accorded the broadest construction consistent with their language.

We claim as our invention: 1. In combination; a circuit breaker having main contacts including a movable contact-member; opening-means operative, at times, to cause an opening movement oi' the movable contactmember; and closing-mechanism operative, at times, to perform an operation tending to cause a closing movement of the movable contact-member; said closing-mechanism including a rotating shaft, an electric motor for driving said shaft, thrust-imparting means effective during approximately one half-rotation of said shaft for imparting a closing-thrust to said movable contactmember, and energizing and controlling means for said motor; said energizing and controlling means being characterized by including a fourposition snap-switch actuated by said shaft and operative, with a quick snapping action, to successively join each of four stationary contacts with the next adjacent stationary contact in response to each quarter-revolution of said shaft, a separate closing-switch, and circuit-means for 'utilizing said closing-switch and two successive Quarter-revolution positions of said snap-switch or energizing the motor during the closing movement of the mechanism and for automatically deenergizing the motor at the completion of said closing movement.

2. In combination, a circuit breaker having main contacts including a movable contactmember; operating-mechanism including an operating-lever which is movable in one direction to close the breaker and which is movable in the other direction to open the breaker; motormechanism for mechanically actuating said operating-lever; and control-means for said motormechanism; said motor-mechanism comprising a rotating shaft, an electric motor for driving said shaft, thrust-imparting means eil'ective during approximately one half-rotation of said shaft for moving said operating-lever in the closing direction and .eifectiveduring approximately the other half-rotation of said shaft for moving said operating-lever in the opening direction; and said control-means being characterized by including a four-position snap-switch actuated by said. shaft and operative, with a quicksnapping action, to successively Join each of four stationary contacts with the next adjacent stationary contact in response to each quarter-revolution of said shaft, a closing-circuit means operative, when energized, to utilize two successive quarterrevolution positions of saidsnap-switch for energizing the motor during the closing movement of the motor-mechanism and for automatically deenergizing the motor at the completion of said closing movement, and an opening-circuit means operative, when energized, to utilize the remaining two successive quarter-revolution positions of said snap-switch for energizing the motor during the opening movement of the motor-mechanism and for automatically deenergizing the motor at the completion of said opening movement.

3. In combination; a circuit breaker having main contacts including a movable contact-member; motor-actuated mechanism operative, at times, to perform an operation tending to cause a closing movement of the movable contact-member; trip-means operable independently of said motor-actuated mechanism to cause an opening movement of the movable contact-member: and an auxiliary switch-contact member operatively associated with the breaker so as to close its contact when the breaker opens and so as to open Aits contact when the breaker closes; said motoractuated mechanism including a rotating shaft, an electric motor for driving said shaft, thrustimparting means effective during approximately one half-rotation of said shaft for imparting a closing-thrust to said movable contact-member, and energizing and controlling means for said motor; said energizing and controlling means being characterized by including a switch-controlling means operatively associated with said shaft in such manner that it energizes a rst motorcircuit conductor during said half-rotation of said shaft and automatically deenergizes said first motor-circuit conductor at approximately the completion of said half-rotation, said switchcontrolling means being further operative to energize a second motor-circuit conductor during a second half-rotation of said shaft and to automatically deenergize said second motor-circuit conductor at approximately the completion of said second half-rotation, a closing-circuit means operative, when energized, to utilize said first motor-circuit conductor for energizing the motor during the closingmovement of the mechanism and for automatically deenergizing the motor at the completion of said closing movement, and an opening-circuit means including said auxiliary switch-contact member and said second motor-circuit conductor for automatically actuating said mechanism to an open position when the circuit breaker is tripped open independently of said motor-actuated mechanism and for automatically deenergizing the motor at the completion of the opening movement of the mechanism.

4. In combination; a circuit breaker having main .contacts including a movable contact-member; motor-actuated mechanism operative, at times, to perform an operation tending to cause a closing movement of the movable contact-member; trip-means operable independently of said motor-actuated mechanism to cause an opening movement of the movable contact-member; an

v its contact when the breaker closes; and a manualY switch normally biased to a predetermined` position; said motor-actuated mechanism including a rotating shaft, an electric motor for driving said shaft, thrust-imparting means eiective during approximately one half-rotation of said shaft for imparting a closing-thrust to said movable contact-member, and energizing and controlling means for said motor; said energizing and controlling means being characterized by including a switch-controlling means operatively associated with said shaft in such manner that it energizes a first motor-circuit conductor during said halfrotation of said shaft and automatically deenergizes said first motor-circuit conductor at approximately the completion of said half-rotation, said switch-controlling means being further operative to energize a second motor-circuit conductor during a second half-rotation of said shaft and to automatically deenergize said second motor-circuit conductor at approximately the completion of said second half-rotation, a closingcircuit means including an actuated position of said manual switch and saidfirst motor-circuit conductor for energizing the motor during the closing movement of the mechanism and for automatically deenergizing the motor at the cornpletion of said closing movement, and an opening-,circuit means including said predetermined biased position of the manual switch and further including said auxiliary switch-contact member and said second motor-circuit conductor for automatically actuating said mechanism to an open position when the circuit breaker is tripped open independently of said motor-actuated mechanism and for automatically deenergizing the motor at the completion of the opening movement of the mechanism.

5. In combination, a circuit breaker having main contacts including a movable contactmember; operating-mechanism including an operating-lever which is movable in one direction to close the breaker and which is movable in the other direction to openthe breaker; motormechanism .for mechanically actuating said operating-lever; trip-means operable independently of said motor-actuated mechanism to cause an opening movement ofLthe movable contact-member; and control-means for said motor-mechanism; said motor-mechanism comprising a rotating shaft, an electric motor for driving said shaft, thrust-imparting means eiective during approximately one half-rotation of said shaft for moving said operating-lever in the closing direction and eiective during approximately the other half-rotation ofk said shaft for moving said operating-lever in the opening direction; and said control-means being characterized byincluding a switch-controlling means operatively associated with said shaft in such manner that it energizes'a rst motor-circuit conductor during said first-mentioned half-rotation of said shaft and automatically deenergizes said rst motor-circuit conductor at approximately the completion of said half-rotation, said switchcontrolling means being further operative to energize a second motor-circuit conductor during said other half-rotation of said shaft and to automatically deenergize said second motor-circuit conductor at approximately the completion of said other half-rotation, a. three-position manual switch normally biased to its central position, an auxiliary switch-contact member oper` atively associated with the breaker so as to close its contact when the breaker opens and so as to open its contact when the breaker closes. a closing-circuit means including one end-position of said manual switch and said first motor-circuit conductor for energizing the motor during the closing movement of the mechanism and for automatically deenergizing the motor at the completion of said closing movement, an openingycircuit means including the other end-position of said manual switch and said second motor-circuit conductor for energizing the motor during the opening movement of the mechanism and for` automatically deenergizing the motor at the completion of said opening movement, and an auxiliary opening-circuit means including said biased central position of the manual switch and further including said auxiliary switch-contact member and said second motor-circuit conductor for automatically actuating said mechanism to 'an open position when the circuit breaker is tripped open independently of said motor-actuated" mechanism and for automatically deenergizing the motor at the completion of the opening movement of the mechanism.

6. In combination, a circuit breaker having 'main contacts including a movable contactmember; operating-mechanism including an operating-lever whichis movable'in one direction to close the breaker and which is movable in the other direction to open the breaker; motormechanism for mechanically actuating said operating-lever; trip-means operable independently of said motor-actuated mechanism to cause.

f operating-lever in the opening direction; and

said control-means being characterized by including a four-position snap-switch actuated by said shaft and operative, with a quick snapping c action, to successively `ioin each of four stationary contacts with the next adjacent stationary contact in response to each quarter-revolution of said shaft, a three-position manual switch normally biased to its central position, an auxiliary switch-contact member operatively associated with the breaker so as to close its contact when the breaker opens and so as to open its contact when the breaker closes; a closing-circuit means including one end-position of said manual switch and operative, when energized, to utilize two successive quarter-revolution positions of said snapswitch for energizing the motor during the closing movement of the mechanism and for automatically deenergizing the motor at the completion of said closing movement, an opening-circuit means including the other end-position of said manual switch and operative, when energized, to utilize the remaining two successive" quarter-revolution positions of said snap-switch for energizing the motor during the opening movement of the mechanism and for automatically deenergizing the motor at the completion `of said opening movement, and an auxiliary opening-circuit means including saidbiased central position of the manual switch and further V including said auxiliary switch-contact member and the aforesaid remaining two successive quarter-revolution positions of said snap-switch for automatically actuating said mechanism to an open position when the circuit breaker is tripped open independently of said motor-actuated mechanism and for automatically deenergizing the motor at the completion of the opening movement of the mechanism.

7. In combination; a circuit breaker having contact-means movable between an open position and a closed position; contact-operating mechanism movable between an open position and a closed position for normally controlling the movement of said contact-means between its corresponding positions; means responsive to predetermined conditions for causing an automatic opening-movement of said contact-means without a corresponding movement of said contact-operating mechanism; an electric actuating-mechanism for normally moving said contact-operating mechanism between its open and closed positions at will; and means responsive to an automatic opening-movement oi' said contactmeans to cause said electric actuating-mechanism to move said contact-operating mechanism toward an open position.

8. In combination; a circuit breaker having contact-means movable between an open position and a closed position; contact-operating mechanism movable between an open position and a closed position for normally controlling the movement of said contact-means between its corresponding positions; means responsive to predetermined conditions for causing an automatic opening-movement of said contact-means without a corresponding movement of said contact-operating mechanism; a first switch-controlled circuit-means operative, when suitably energized, to cause said contact-operating mechanism to move to its open position; a second switch-controlled circuit-means operative, when suitably energized, to cause said contact-operating mechanism to vmove to its closed position; and means responsive to an automatic openingmovement of said contact-means to cause said contact-operating mechanism to move to its open position.

9. In combination; a circuit breaker having contact-means movable between an open position and a closed position; contact-operating mechanism movable between an open position and a closed position for normally controlling the movement of said contact-means between its corresponding positions; means responsive to predetermined conditions for causing an automatic opening-movement of said contact-means without a corresponding movement of said contact-operating mechanism; a first switch-controlled circuit-means operative, when suitably energized, to cause said contact-operating mechanism to move to its open position; a second switch-controlled circuit-means operative, when suitably energized, to cause said contact-operating mechanism to move to its closed position;

and means responsive to an automatic openingmovement of said contact-means to energize said iirst switch-controlled circuit-means.

10. In combination; a circuit breaker having contact-means movable between an open position and a closed position; contact-operating mechanism movable between an open position and a closed position for normally controlling the movement of said contact-means between its corresponding positions; means responsive to predetermined conditions for causing an automatic opening-movement of said contact-means without a corresponding movement of said contact-operating mechanism; a first switch-controlled circuit-means operative, when suitably energized, to cause said contact-operating mechanism to move to its open position; a second switch-controlled circuit-means operative, when suitably energized, to cause said contact-operating mechanism to move to its closed position; manually operated switch-means for initiating the energization of either said iirst or second circuit-means at will; and automatically operated switch-means for cutting-oi! the energization of f said iirst and second circuit-means, respectively,

at approximately the end oi' the corresponding movement of the contact-operating mechanism, said automatically operated switch-means including a four-position snap-switch, and means for actuating said snap-switch twice during each opening movement of the contact-operating mechanism and twice during each closing movement of the contact-operating mechanism.

11. In combination; a circuit breaker having contact-means movable between an open position and a closed position; contact-operating mechanism movable between an open position and a closed position for normally controlling the movement of said contact-means between its corresponding positions; means responsive to predetermined conditions for causing an automatic opening-movement of said contact-means without a corresponding movement oi said contact-operating mechanism; a first switch-controlled circuit-means' operative, when suitably energized, to cause said contact-operating mechanism to move to its open position; a second switch-controlled circuit-means operative, when suitably energized, to cause said contact-operating mechanism to move to its closed position: manually operated switch-means for initiating the energization of either said liirst or second circuit-means at will; and means responsive to an automatic opening-movement of said contactmeans and to a non-actuated condition oi' said manually operated switch-means for automatically energizing said iirst switch-controlled circuit-means.

TURE LINDSTROM. JEROME SANDIN.

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