US2349647A - Electric control system - Google Patents

Description

May 28,-1944. A. z. BOISSEAU mL 2,849,647

ELECTR IC CONTROL SYSTEM Filed Sept. 16, 1941 2 Sheets-Sheet 1 T0 CLOSE GIEGUIT INTERRUPTEE Inventors: 'Alexa'nw'ziev` C. Bosseau Benjamin S. BeaI |,I by 'JVWMMWA Th em Atto'rn eg.

May 23, 1944- A. c. BolssEAu ErAL 2,349547 t ELECTRIC CONTROL SYSTEM Filed Sept. 16, 1941 2 Sheets-Sheet 2 Cl RCUIT I NTEEE'UF'TEE To cLosE I Patente'd May 23, 1944 UNITED STATES PATENT OFFICE ELECTRIC CONTROL SYSTEM York Application September 16, 1941, Serial No. 410,980

8 Claims.

Our invention relates to an electric control system for controlling a single predetermined operation such as a circuit-interrupter olosing operation so as not only to insure completion thereof but also to prevent recurrent Operations when only a single control operation has been initiated by the operator. In its broadest aspect, our invention is concerned with an electromagnetic control means which might be used for controlling an electric circuit breaker. More particularly, our invention is in the nature of an improvement on the invention disclosed and claimed inV copending application, Serial No. 373,447, filed January 7, 1941, on behalf of Carl Thumim, and assigned to the same assignee as the present application.

It is a common expedient in control systems for circuit interrupters to initiate the closing operation by closing a manual switch of some sort. Generally, the closing of this switch initiates the operation of suitable motive means for moving the circuit interrupter to the closed position. If this switch remains in the closed position after the closing operation has been completed and the circuit interrupter immediately opens due to an abnormal condition on the power circuit which it controls, obviously, the closing circuit of the circuit interrupter is again completed as soon as it reaches its open position and the closing operation is repeated. Under these conditions, a circuit interrupter continues to open and close rapidly while the abnormal condition persists and the manual switch remains in its circuit-closing position. This so-called pumping action if allowed to Continue may result in serious damage to the associated apparatus.

Many antipumping arrangements have been proposed which usually depend upon electromagnetic means for rendering the control circuit ineffective at the completion of a closing operation if the manual initiating switch remains closed; However, in most such arrangements, the closing operation could be initiated even though such electromagnetic means or antipumping means were defective and considerable damage to associated apparatus might result due to such defect, which permitted pumping of the device or the like. It would be desirable to provide an improved arrangement like the copending application referred to above in which no closing operation which might damage the actuating portions of the apparatus could occur if, for any reason, the electromagnetic means failed to respond when the manual switch to initiate the closing operation is actuated.

It is an object of our invention to provide a new and improved control system for an electric circuit.

It is another object of our invention to provide a new and improved control system which includes the advantage set forth above and which is more simple, compact, and less liable to get out of adjustment than other arrangements known heretofore.

It is a further object of our invention to provide a new and improved arrangement for preventing the repeated opening and closing of a circuit interrupter under the conditions mentioned above.

Further objects and advantages of our invention will become apparent as the following descriptionv proceeds and the features of novelty which characterize our invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of our invention, reference may be had to the accompanying drawings in which Fig. 1 is a partly diagrammatic layout of an electric control system and apparatus illustrating a specific application of our invention, Figs..2 and 3 illustrate a portion of the apparatusv shown in Fig. 1 and represents successive positions assumed by this apparatus during the operation of the electric control system, and Fig. 4 is a partly diagrammatic layout similar to Fig. 1 illustrating another modification of our invention.

As will be understood by those skilled in the art, any suitable motive means may be utilized for moving to a predetermined position, such as the closed position, the device to be operated, such as' the circuit interrupter. Such motive means may comprise motors of various sorts, such as fiuid motors, pneumatic motors, dynamoelectric machines, solenoid motors, and the like, all ofv which may be Controlled directly or indirectly by electric/means. In order to illustrate our invention, we have chosen in Fig. 1 to illustrate this motive means as comprising electric motor IO which rotates an Operating cam in a counterclockwise direction through suitable connections, such as a worm and drive gear 12 and I 3. Operating cam is illustrated as being connected in any suitable manner to means to be actuated, such as by longitudinally guided operating rod i4 having a roller I 5 engaging the camactuating face. Preferably rod I-'l is connected to an electric circuit breaker through a suitable trip-free mechanism, not shown, so that upward movement thereof upon counterclockwise rotation of Operating cam ll causes closing of the to be energizecl from an electric supply Circuit 16, the energization of the motor circuit being Controlled by a motor switch |1.

The motor switch |1 is provided with an electromagnetic actuating means including a solenoid IS, the moving element or armature |9 of which is connected to the movable Contact structure of switch 11 and is likewise provided with a contact for bridging seal-in contacts 2| when solenoid l is energized. Energization of the solenoid l3 from the supplytcircuit IG and closing of motor switch l1 is obtained upon closing of a normally open switch 22 adapted to bridge Contacts.23 associated therewith.

In order to control the energization and deenergization of the control circuit of solenoid l and thereby to render the motive means effective and ineffective, we provide electromagnetic means generally indicated at 24. Electromagnetic means 24 include a magnetic structure having a single winding 25 thereon which controls two'independent armatures 21 and 28, respectively, pivotally mounted about a common pin or pivot point 29. The inner armature 21 is light and constructed so as to be moved with a relatively small force acting thereon and is always maintained within the coercive zone of the electromagnet comprising magnetic structure 25 and winding 26 by means of a suitable stop engaging an extension 3| of armature 21. position indicated in Fig. 2 upon energization of winding 26 so as to cause switch 22 to bridge contacts 23as the armature 21 approaches its fully attracted position, thereby energizing the control circuit of solenoid l8 and indirectly energizing the control circuit for the motive means comprising motor I!! so as to initiate the closing stroke of the circuit interrupter.

The second armature 28 is much heavier than armature 21 and ignormally held outside the coercive zone of the electromagnet comprising magnetic structure 25 and winding 26 by spring means 32 connected so as to cause armature 23 to pivot about pin 29 in a counterclockwise direction. Armature 28 is provided with an extension 33 connected' to support a limit switch 34 which normally bridges contacts when armature 28 is in the position indicated in Figs. l and 2. ;Contacts 35 are connected in the control circuit for solenoid I8 in series with contacts 23.

The particular construction of armatures 21 and 22 is not important in so far as our invention is concerned and several different arrangements can be used. For example, armature 25.X might be channel shaped so as to embrace armature 21 when in` the position indicated by 3. or, as shown in the drawings, armature 28 may be arranged in adjacent relationship to armature 21.

Although armature 28 in the unattracted positions of Figs. 1 and 2 outside the coercise zone of electromagnetic means 24 cannot be pulled into the position of Fig. 3 by energization of winding 26, nevertheless, if armature 28 were moved to Armature 21 is arranged to move to the the position of Fig, 3, the magnetic force of the electromagnet comprising magnetic structure 25 and winding 26 would be sufficient to hold armature 28 in the attracted position of Fig. 3. In other words, armature 21 is constructed so as to be saturable so that there is an ample surplus of magnetic field available to hold armature 28 in the position indicated in Fig. 3 once it has been moved by an external force to this position.

For the purpose of deenergizing the control circuit of the motive means, such as motor Ill, in accordance with a predetermned operation thereof, we have provided a cam 36 mounted on longitudinally guided operated rod M which engages with a horizontally movable member 31 when Operating rod M reaches a predetermined position so as to force member 31 against heavy armature 28 hitherto unresponsive in lying beyond the coercive range of the electromagnet comprising magnetic structure 25 and winding 23. Member 31 forces armature 28 to rotate about pin 29 in a clockwise direction until it is forced against armature 21 which is in the attracted position shown in Figs. 2 and 3. Just as armature 23 is about to assume theposition shown in Fig. 3, limit switch 34 is opened to interrupt the control circuit of solenoid IB and, consequently, to deenergize the control Circuit of the motive means including motor |0. As long as winding 26 remains energized, armatures 21 and 28 are held in the positions indicated in Fig. 3 to preventpumping of the apparatus in the event the circuit breaker is closed on an abnormal current condition on the system which it is de- -V signed to control. i

Winding 26 of electromagnetic means 24 Jis preferably energized from supply circuit IB through push button control or operatofs switch 38 which may be manually closed by the operator to initiate the closing operation. This operation may also be automatically initiated by automatic reclosing switch 39 paralleling switch 38 which may be Controlled in a manner well known to those skilled in the art. Seal-in contacts for solenoid IB also parallel push button 33 to seal in the circuit of winding 26 of electromagneti'c means 24.

4 The operation of our invention will be well understood by those skilled in the art in view of the detailed description included above. A closing operation of the circuit breaker connected to operating rod |4 may be initiated by depressing push button 38 or by automatic closure of switch 39 whereupon the winding 26 of electromagnetic means 24 is energized to attract armature 21, which is within the coercive zone thereof, to the position indicated in Fig. 2. Such operation of armature 21 causes switch 22 to bridge contacts 23 to close the control circuit of solenoid IB through the contacts 35 of limit switch 34 and push button switch 38, whereupon solenoid IB causes seal-in contacts 2| to be bridged and Closes the control circuit of the motive means comprising motor Ill to initiate the closing operation of the associated circuit breaker by counterclockwise rotation of cam Il. When the circuit breaker Controlled by Operating rod |4 approaches its Closed position, cam 36 engages member 31 to move heavy armature 28 from the positions indicated in Figs. 1 and 2 to the position indicated in Fig, 3, thereby opening limit switch 34 and deenergizing the'control circuit of solenoid l8 as well as the control circuit for the motive means which operates the circuit breaker. As long as the operator's switch 38 or vautomatic reclosing switch 39 remains closed, winding 26 remains energized to hold heavy armature 28` in the position of Fig. 3 so that only a single operation can occur and repeated closures or pumping of the Circuit breaker will not result if the Circuit breaker were closed on an abnormal current condition existing on the circuit which it Controls. In the event that electromagnetic means 26 should become defective, the Circuit breaker Closing operation would not be initiated as in prior-art devices so that the danger of improper operation of the limit switch would not arise as was the case in such prior-art arrangements.

Since our invention is well adaptecl for use in connection with pneumatic or fiuid-operated motor means, we have Chosen in Figi` 4 to illustrate such an application of our invention. The corresponding parts of Fig. 4 are designated by the same reference numerals as in 1 to Although the straight-line motion of a pistontype fiuid motor is readily adapted to be connected directly to Operating rod l4 for Operating a circuit breaker, we have Chosen to illustrateJ in Fig. 4 a fluid motor 43 connected for moving Operating rod M upwardly through the aid of a cam 4| in the same manner as rotation of cam Il accomplishes this result in Fig. 1.

Fluid motor 40 is illustrated as comprising a cylinder 42 and a piston 43. A suitable spring 44 is provided to tend to hold piston 43 in the position indicated in Fig. 4. Fluid from a source not shown is connected through Conduit 45, valve 46, and conduit 41, to one end of cylinder 42 so that opening of valve 4B will cause piston 43 to move cam 4! toward the right to cause closure of the circuit breaker associated with Operating rod |4. Valve 46 vmay be Controlled electrically by means of a solenoid 48, connected in an electric control circuit including the contacts 35 of limit switch 34 and the contacts 23 of normally open switch 22 in the same manner as the solenoid 18 of Fig. 1. Solenoid 48 also controls a seal-in switch 20 for bridging contacts to parallel push button 38 and automatic reclosing switch 33 so as to prevent the deenergization of the winding 26 of electromagnetic means 2-4 prior to the completion of the closing operation in the event that push button 38 or reclosing switch 39 were opened.

In view of the detailed description include-d above, the operation of the arrangement disclosed in Fig. 4 will be obvious to those skilled in the art and no further discussion will be included herewith.

It should be understood that our invention is not limited to the specific details of construction herein illustrated and that changes and modifications may occur to one skilled in the art without departing from our invention and we, therefore, aim in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent of the United States, is:

1. In a circuit interrupter controlling system comprising motive means for moving said circuit interrupter to the closed position. an electric control circuit for effecting the operation of said motive means, means including a first switch for rendering said electric control circuit effective to initiate operation of said motive means to move said Circuit interrupter to the closed position, electromagnetic means including a plurality of armatures one of which is arranged for Operating said first switch, means including an operator's switch for energizing said electromagnetic means to operate said first switch and initiate closing of said circuit interrupter, and means responsive to a predetermined operation of said motive means for rendering said first switch ineifective to control the energization of said control circuit.

2. In` a circuit interrupter controlling system comprising motive means for moving said Circuit interrupter to the closed position, an electric control circuit for effecting the operation of said motive means, electromagnetic means including a plurality of armatures for causing energization and deenergization of said control Circuit to render said motive means effective and inefiective to close said circuit interrupter, means including an operator's switch for controlling the energization of said electromagnetic means to move one of said armatures to initiate the closing operation of said circuit interrupter, means responsive to a predetermined operation of said motive means for moving another of said armatures to cause deenergization of said control Circuit, and means responsive to the contnued energization of said clectromagnetic means for maintaining said control Circuit in a deenergized condition as long as said operatofs switch remains closed.

3. In a controlling system for an electric circuit interrupter, motive means for moving said circm't interrupter to the Closed position, an electric Control Circuit for eifecting the operation of said motive means, a first and second switch in said control circuit for controlling the operation of said motive means, electromagnetic means including a plurality of armatures, means including an operator's switch for initiating the energization of said electromagnetic means, one of said armatures of said electromagnetic means being so constructed and arranged to operate said first switch to the closed position so that operation of said motive means is initiated upon actuation of said operatoris switch, said other armature being unaffected by initial energization of said electromagnetic means, and means for movin'gr said other armature to cause operation of said second switch and deenergization of said control circuit in response to closure of said circuit interrupter, said electromagnetic means being so constructed and arranged as to hold said other armature in a position to maintain said second switch in the open position as long as said electromagnetic means is energized.

4. In a circuit interrupter controlling system comprising motive means for moving said circuit interrupter to the closed position, an electric control circuit for effecting the operation of said motive means, electromagnetic means including a plurality of armatures pivoted at a common point for causing energization and deenergization of said control Circuit to render said motive means effective and ineffective to close said circuit interrupter, means including an operator's switch for controlling the energization of said electromagnetic means to move one of said armatures to initiate the closing operation of said Circuit interrupter. means responsive to a predetermined operation of said motive means for moving another of said armatures to cause deenergization of said control circuit, and means responsive to the continued energization of said electromagnetic means for maintaining said control circuit in a deenergized condition as long as said operator's switch remains closed.

. 5. In a control systeml for an 'electric circuit, electromagnetic means comprising a magnetic structure having only a singlev winding associated therewith for controlling the energization and deenergization of said circuit including a first and a second armature, a first means operated by said first armature, a second means operated by said second armature, means for` energizing said winding to cause said first armature to operate said first means, means for biasing said second armature to a positionoutside the coercive range of said electromagnetic means so as to be unaffected by energization of said winding, and means independent of said electromagnetic means but olependent upon operation of said first named means for moving said, second armature into the coercive range of said electromagnetic means to control said second means.

6. In a control system for an electric circuit, electromagnetic means comprising'a magnetic structure having only a single winding associated therewth for controlling the energization and deenergization of said circuit including a first and a second armature each pivotally mounted about a common pivot so as to be movable relative to said magnetic structure, a first switch operated by said first armature, a second switch operated by said second armature, means for energizing said Winding to cause said first armature to close said first switch, means for biasing said second armature to a position outside the coercive range of said electromagnetic means so as to be unaffected by energizaton of said winding, and means independent of said electromagnetic means but dependent, upon operation of said first switch for movingrsaid second armature into the coercive range of said electromagnetic means to open said second switch, the continued energization of said electromagnetic means causing said second armature to maintain said second switch in the open position.

-7. In a circuit-interrupter controlling system comprising fluidwoperated means for moving said circuit interrupter to the closed position, an electrically operated valve for controlling the operation of said fiuid-operated means,an electric control circuit for efiecting the operation of said electrically operated valve, means including a first switch for rendering said electric control circuit effective to cause said fluid-operated means to move said circuit breaker to' the closed position, electromagnetic meansincluding a plurality of armatures one of which is arranged for Operating said first switch, means including an operatorls switch for energizing said electromagnetic means to operate said first switch and initiate closing of said circuit interrupter, and means responsive to a predetermined operation of said motive means for rendering said first switch ineifective to control the energization of said control circuit.

8. In a circuit-interrupter controlling system comprising cam means for movingv said circuit interrupter to the closed position, a motor for driving said cam, an electric control circuit for eifecting the operation of said motor, electromagnetic means including a pluralityV of armatures for causing energization and deenergization of said control circuit to render said motor effective and ineifective to close said circuit'interrupter through said cam means, means including an operatons switch for controlling the energization of said electromag'netic means to move one of said armatures to initiate the closing operation of said circuit interrupter, means responsive to a predetermined operation of said motive means for moving another of said armatures tocause deenergization of saidV control circuit, and means responsive to the continued energization of said electromagnetic means for maintaining said control circuit in a deenergized condition. as long as said operatoris switch remains closed.

i ALEXANDER C. BOISSEAU.

BENJAMIN S. BEALL, III.

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