US2561452A - Circuit testing repeating circuit breaker - Google Patents

Description

y 1951 A. VAN RYAN ETAL 2,561,452

CIRdUIT TESTING REPEATING CIRCUIT BREAKER Filed Jan. 13, 1949 INVENTORS 952% X412 Zyaw BY W ,F/ E/d Z2; mdm

Patented July 24, 1951 UNITED STATES PATENT OFFICE 2,561,452 o aoU 'r TESTING REPEATINQ clnoprr liBEAK EK Anthony Van Ryan, South Milwaukee, and Max Rigert, Milwaukee, Wis., assignors to McGraw Electric Company, a corporation of Delaware Application January 13, 1 3 4 9, serial No. 70,755

l 2 This invention relates to a circuit testing re- 9 and ID. The levers I and 8 are actuated by peatin'g circuit breaker. means of over-center springs II and I2 whose Objects of this invention are to provide a circuit breaker which is so made that after opening'under overload it will ascertainthe condition of the load circuit by testing or probing such circuit tofind out if there still exists an overload condition before the load circuit is again directly connected to the supply circuit by means of the self-closing circuit breaker, which does not dependupon the balancing of voltages'or currents, and which has no special relaysor coils for ascertaining the condition of the load circuit but which utilizes its own opening coil in coaction with a testing or probing switch to prevent closing'of the circuit breaker when the impedance of the load circuit is below a certain predetermined value.

' More specifically, objects of this invention are to provide a self-closing circuit breaker which is so constructed that the circuit breaker closes a testing or probing circuit prior to closing the main circuit, and in which this probing circuit includes the opening coil and the load circuit,the arrangement being such that a reduced current is allowed to flow through the load 'circuit, such current being sufficient to actuate the opening coil in the event that a fault or other overload exists in the load circuit.

Further objects are to provide a circuit breaker An embodiment of the invention is shown inthe accompanying drawings, in which:

The single figure is a partly diagrammatic view showing the circuit breaker.

Referring to the drawing, it will be seen that the supply mains or supply lines are indicated by the reference character I and the load lines or load circuit by the reference character 2. 'The main switch of the circuit breaker is indicated generally by the reference character! andthe auxiliary, testing or probing switch by the reference character 4. The main switch is operated by a main operating rod 5 and the auxiliary switch by auxiliary operating rod 6 which are respectively operated by means of a main lever I and an auxiliary lever 8 pivoted as indicated at I outer ends are connected to such levers and whose inner ends are connected to a rod [3 extending upwardly from the operating plunger Id of the circuit breaker. The plunger I4 is adapted to be drawn downwardly by means of the overload-series coil l5 and is biased upwardly by means of the spring I? It is connected to a time delaymeans indicated generally by the reference character 18 which is delayed in the direction indicated by the arrow.

Normally the parts are in the position shown. However, when an overload occurs it will be seen that" the opening or trip coil I5 will draw the plunger l4 downwardly, as viewed in the'single.

figure of the drawing, and will move the overcenter springs H and I2 past dead center and will cause the main and auxiliary switches 3 and '4 to open, thus disconnecting the load circuit 2 from the supply mains I.

' After the circuit breaker has opened, the bias- Y ing' spring I! slowly moves the plunger I4 upwa'rdly in a slow manner due to the time delay means [8 and closes the testing or auxiliary switch 4 before the main switch 3 arrivesat closing position. As soon'as'th'e auxiliary switch has closed, it will beseen that an'auxiliary circuitisestablished through an impedance l8 and the opening'coil [5 to the load circuit and'a reduced voltage is impressed on the load circult: If the" load circuit is clear of any fault or overload,thecircuit breaker will continue its closing motion and will close the main switch 3'; the auxiliary or testingswitoh 4 remaining closed. However, if the fault is'a permanent fau1t;it isapparent that as scenes the auxiliary switch closes, which occurs at a time prior to the arrival of the main switch at closing position, the

auxiliary circuit through the impedance It! would pass sufficient current through the openingcoil I5 to cause the plunger I4 to move downwardly and open the auxiliary switch 4, the main switch 3 never having arrived at closed position.

This operation would continue indefinitely for a permanent fault except for the fact that integrating and lock-out means have been provided which will now'be described.

The integrating means comprises the integrating or counting ratchet l 9 and the spring pressed pawl 20 pivoted to the auxiliary rod 5 and normally held clear of the ratchet 19 by means of a stop 2|. The integrating ratchet I 9 is biased upwardly in any suitable manner as by means of indicated at 30. latch 21 which is pivoted as indicated at 3| has at 30 and is manually operable. operable lever 33 is provided with an extension 34 which is normally held in engagement'with the downwardly biased or spring pressed lever 28 the spring 22 and a time delay means indicated generally by the reference character 23 is provided to delay resetting of the integrating means. n repeated operations of the circuit interrupter, it will be seen that the integrating means is moved downwardly a plurality of steps provided the successive operations occur with s'ufiicient rapidity. When the integrating means has been moved downwardly to its lowest position, it will depress a lever 24 whose outer end is arranged to be engaged by a shouldered portion 25 carried by an extension rod 26 projecting upwardly from the integrating ratchet or counting ratchet IS. The lever 24 is rigid with a latch member 21 which normally restrains the downward motion of a lever 28. downwardly by means of a relatively heavy lockout spring 29, which spring is much more powerful than the biasing spring I1. The spring 29 acts on the lever 28 and such lever is pivoted as It is apparent that when the been rocked to releasing position by means of the integrating or counting means, that the lever 28 will be free to rock downwardly. It is arranged to engage a projecting member 32 carried by the rod l3 of the plunger l4 and to thus force the plunger downwardly thereby opening both the main switch 3 and the auxiliary or testing switch 4'and locking the circuit interrupter in open -position.

It is to be noted that a lever 33 is also pivoted This manually by means of a spring 35. The manually operable lever 33 constitutes both a manual trip means and also a manual reset means.

When it is used as a reset means after the circuit breaker has been locked in open position, it is pushed upwardly and thereb pushes the lever 28 upwardly against the action of the spring 29. This rocks the latch 21 in a clockwise direction, the lever 28 passing above the latch. The latch 21 is spring biased in a counterclockwise direction by means of the spring 36. i

' It is to be noted that after lock-out has occurred, that when the reset lever '33 is moved upwardly, it will compress the spring 29 and position the lever 28 above the latch'2'l and allow the opening spring H to move the plunger upwardly. This closes both the auxiliary and main "switches and allows the pawl 20 to detachitself from the integrating ratchet l9 and allows the integrating means to reset itself.

When itis desired to manually trip and lock the circuit breaker in open position, the lever 33 is pulled downwardly and a projection 31 'thereon engages a lever 38 which is rigid with the latch 21. This rocks the latch 21 in a clockwise direction and frees the lever 28, so that the lock-out spring 29 is now effective to lock the circuit interrupter in open position.

It is to be understood that no attempt has been made to show how the various switch parts are insulated from each other or from other portions ofthe apparatus. It is to be understood that any suitable and well known mean can be employed.

'Also it is to be understood that no particular effort has been made to show guiding means for the various portions of the circuit breaker and that any suitable formof guiding means can be employed.

It will be seen that a novel-tormxof circuit either a choke coil or a resistance for an alter- The lever 28 is spring' pressed nating current circuit.

It will be seen further that integrating or counting means have been provided which respond to 'a predetermined number of operations of the circuit breaker occurrin in rapid succession and which integrating means is effective to cause lockout of the circuit breaker thereby holding both the main switch and the probing or testing auxiliaiy switch in open position.

It is to be noted particularly that no auxiliary relays or auxiliary equipment is required, but instead the opening coil of the circuit breaker itself is employed in conjunction with testing means to test or probe the load circuit.

Although this invention has been described in considerable detail, 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: i

' I 1. A circuit breaker arranged to be connected between a supply circuit and a load circuit comprising main switch means controlling the connection of the supply circuit to the load'circuit, auxiliary switch means, an operating plunger, mechanism connecting said plunger and saidmain and auxiliary switch means and arranged to open and close said main and auxiliary switch means when said operatin plunger moves to switch open and switch closed position, biasing means biasing said plunger to switchclosed position, said mechanism being arranged to close said auxiliary switch means prior to the closing of said main switch means, time delay means delaying the motion of said auxiliary switch means towards switch closed position, a magnet coil arranged to move said plunger to switch open position upon the occurrence of an overload, said coil being normally a connected in series with said supply circuit and said load circuit, and an auxiliary circuit connected ahead of said main switch means to said supply circuit and including an impedance and said auxiliary switch means connected to said magnet coil and arranged to pass a limited current through said magnet coil and said load circuit upon continuing overload when said auxiliary switch is closed and said main switch is open to thereby cause said plunger to move to switch open position prior to closing said main switch I means.

2. A circuit breaker arranged to be connected 1 between a supply circuit and a load circuit commechanism connecting said plunger and said main and auxiliary switch means and, arranged to open and close said main and auxiliary switch means when said operating plunger moves to switch open and switch closed position; biasing means biasing said plunger to switch closed position, said mechanism being arranged to closesaid auxiliary switch means prior to the closing or said main switch means time delay means delaying the motion of said auxliliary switch means towards switch closed position, a magnet coil arranged to move said plunger to switch open position upon the occurrence of an overload, said coil being normally connected in series with said supply circuit and said load circuit, an auxiliary circuit connected ahead of said main switch means to said supply circuit and including an impedance and said auxiliary switch means connected to said magnet coil and arranged to pass a limited current through said magnet coil and said load circuit upon continuing overload when said auxiliary switch is closed and said main switch is open to thereby cause said plunger to move to switch open position prior to closing said main switch means, normally inactive lock-out means, and counting means responsive to a plurality of closely successive circuit interrupting operations of the auxiliary switch for releasing said lock-out means for locking said operating plunger in switch open position.

3. A circuit breaker arranged to be connected between a supply circuit and a load circuit comprising main switch means controlling the connection of the supply circuit to the load circuit, auxiliary switch means, an operating plunger, mechanism connecting said plunger and said main and auxiliary switch means and arranged to open and close said main and auxiliary switch means when said operating plunger moves to switch open and switch closed position, biasing means biasing said plunger to switch closed position, said mechanism being arranged to close said auxiliary switch means prior to the closing of said main switch means, time delay means delaying the motion of said auxiliary switch means towards switch closed position, a magnet coil controlling said plunger and connected in series with said load circuit and being responsive to overload condition, counting means responsive to a plurality of closely successive operations of said auxiliary switch means, lock-out means controlled by said counting means for locking said circuit interrupter in open position, means including said auxiliary switch means for passing a limited current through said magnet coil on continued overload, and manually operable means for selectively tripping or resetting said lock-out means.

ANTHONY VAN RYAN. MAX RIGERT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,534,724 McDonald Apr. 21, 1925 2,468,498 Kyle Apr. 26, 1949 FOREIGN PATENTS Number Country Date 12,393 Holland Jan. 15, 1925

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