US2436194A

US2436194A - Circuit breaker operating means

Info

Publication number: US2436194A
Application number: US613505A
Authority: US
Inventors: Ralph R Bush
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1945-08-30
Filing date: 1945-08-30
Publication date: 1948-02-17
Anticipated expiration: 1965-02-17
Also published as: GB639774A

Description

Feb. 17, 1948. R. R. BUSH CIRCUIT BREAKER OPERATING MEANS Filed Aug. 30, 1945 44 mil n:

Fig.2.

hwven tor: Ralph RBush,

H i s Atfiorm ey.

Patented Feb. 17, 1948 CIRCUIT BREAKER OPERATING MEANS Ralph R. Bush, Upper Darby, Pa., assignor to General Electric Company, a corporation of New York Application August 30, 1945, Serial No. 613,505

Claims. 1

My invention relates to switches and electric circuit breakers, and more particularly to operating means for electric circuit breakers.

Electric circuit breakers and switches are usually provided with suitable means for opening and closing the same. In many types of circuit breakers it is common practice to provide a solenoid operated mechanism for closing the breaker. During the closing operation suitable opening springs are charged and the breaker is latched closed with the latch holding the opening springs in charged condition in readiness for high speed opening of the circuit breaker. Sometimes such circuit breakers or switches are closed when a very abnormal current condition exists on the circuit controlled thereby. Such an abnormal current condition might be a short circuit and under such conditions it is desired to open the circuit breaker at high speed. It is obvious that when such a circuit breaker is closed on a short circuit an arc will be drawn before the contacts are completely closed and before the opening springs arecompletely charged. Consequently the opening springs, which are not completely charged, produce a weak opening action with a resultant unsatisfactory opening operation. It would be desirable to provide some supplementary or auxiliary means to speed the opening of the circuit breaker under such conditions.

It is an object of my invention to provide a new and improved operating means for electric circuit breakers and switches.

It is another object of my invention to provide a supplementary opening means for circuit breakers which supplementary opening means is simple and compact and which is instantly operative to open the circuit breaker under abnormal conditions of the circuit when the normal means for opening the circuit breaker are inadequate.

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

For a better understanding of my invention reference may be had to the accompanying drawing in which Fig. 1 is a schematic diagram of a portion of an electric circuit interrupter embodying my invention, and Fig. 2 is an enlarged sectional View of a portion of the operating mechanism shown in Fig. 1.

Although my invention may be applicable to any sort of electric switch or circuit breaker, it is particularly applicable to electric switches or circuit breakers employing the operating mechanism disclosed and claimed in United States Letters Patent 1,988,287, Thumim. and copending application Serial No. 567,468, Baskerville, filed December 9, 1944, both assigned to the same assignee as the present application.

Referring now to Fig. 1, there is illustrated a portion of an electric circuit breaker embodying my invention. This circuit breaker is designated by the numeral l and comprises a pair of relatively movable contacts 2 and 3. The contact 3 is a movable contact and is supported on an arm 4 rotatable about a pivot 5. Contacts 2 and 3 are connected through suitable insulated

conductor studs

6 and 1 to an electric power line 8 adapted.

to be controlled thereby. Such a circuit breaker is usually a polyphase breaker but to simplify the drawing only a single phase thereof is shown.

In order to cause relative movement between the contacts 2 and 3 movable contact supporting arm l is connected through a suitable operating rod 9, a crank Ill pivotally mounted at H, and a suitable link l2 with a collapsible thrust transmitting linkage generally indicated at I 3 and mounted in a housing 14 closely associated with the housing of circuit breaker I.

Any suitable motive means for operating mechanism I3 may be provided such for example as a fluid motor, electric motor, solenoid, or the like. As illustrated in Fig. l, the motive means generally indicated at I5 is mounted below operating mechanism l3. This motive means actuates a plunger I6 which is arranged for vertical movement. The thrust transmitting linkage I3 which provides a trip free mechanism comprises.

an operating crank l1 pivotally mounted at l8. One end of operating crank I! is pivotally connected as at [9 to link I 2. The other end of operating crank I! is connected by pivotal means as indicated at 22 to a collapsible or floating linkage which is very similar to that disclosed and claimed in Thumim Patent 1,827,626, granted October 13, 1931, and assigned to the same assignee as the present application.

This floating 0r collapsible linkage comprises a link 2| and a link 22 pivotally related by a shaft having an extension 23. The free end of link 22 is pivotally connected, as indicated at 24, with a crank or lever 25 rotatable about a fixed pivot 25. It will be observed from the drawing that links 2| and 22 form a toggle with the shaft having the extension 23 comprising the knee joint thereof. The plunger [6 is adapted in its upward movement to engage a roller 2! positioned at the knee of the toggle and upward movement of plunger l6 straightens the toggle comprising links 2| and 22 and causes rotation of operating crank ll in a counter-clockwise direction about pivot H3. The limiting movement of the toggle comprising links 2| and 22 is determined by an extension 28 on link 2| which cooperates with a pin 29 on link 22 in a manner which is clearly obvious from Fig. 1.

Rotatable about the axis of pivot 24 between link 22 and crank 25 is trip latch roller 30 which is adapted to rest on a stop bolt 3| supported from the base 32 of housing it. A suitable resetting spring 33 tends to rotate crank or lever 25 in a counter-clockwise direction so that trip latch roller 33 tends to be in engagement with stop 3|. It will be obvious that if trip latch roller 30 is maintained in a fixed position against stop bolt 3| a force applied to toggle roller 21 will cause rotation of crank l7 about pivot l8. If, however, trip latch roller 30 is free to move away from stop bolt 3| then the thrust transmitting linkage collapses toward the right and rotation of operatingcrank i7 will not occur for the toggle links 2| and 22 straighten and cause crank 25 to rotate clockwise against the bias of its resetting spring 33.

In order to hold trip latch roller 3|] against stop bolt 3| thereby to control the collapsible linkage, there is provided a trip latch 34 pivotally mounted at 35. A trip latch spring as biases trip latch 3:3 to the position indicated in Fig. 1 against stop 31. In this position trip latch 34 holds trip latch roller 39 in a fixed position against stop bolt 3|. A suitable trip coil 38 positioned in the manner disclosed and claimed in Thumim Patent 1,988,287 referred to above is provided. When plunger 39 associated with trip coil 38 is moved to the left as viewed in Fig. 1 trip latch 34 is rotated so that trip latch roller 30 is free to move with lever or crank 25 about pivot 26 causing collapse of the collapsible thrust transmitting linkage l3.

In order to restrain the collapsible linkage in the thrust transmitting breaker-closed position indicated in Fig. l, a pivotally mounted prop 40 is provided rotatable about a shaft 4|. A suitable spring 42 biases prop 40 in a clockwise direction against a stop 43. When the collapsible linkage is moved by the plunger It to the position indicated in Fig. 1, the prop 40 moves under the extension 23 of the shaft forming the knee of the toggle comprising links 2| and 22 to hold the linkage in the thrust-transmitting position even though plunger l6 returns to the position indicated in Fig. 1.

In order to cause high speed opening of the circuit breaker I there are provided suitable circuit breaker opening springs such for example as the spring 44. The energy stored in spring 44 is adapted to be transmitted through an operating rod 45 to crank I8. Spring 44 is adapted to be charged during the closing operation of the circuit breaker so as to be in readiness to cause high speed opening of the circuit breaker in the event that trip coil 38 is energized either automatically in response to an overload condition, or manually when opening of the breaker is initiated manually.

In the event that circuit breaker is closed when an abnormal current condition such as a severe short circuit exists on power line 8, trip coil 38 will be energized to cause opening of the breaker before opening spring 44 is completely charged. High speed opening of circuit breaker is desired particularly under such conditions when spring 44 is incapable of causing such opening, namely, when opening is initiated prior to complete charging of spring 44. To insure satisfactory opening operation under such conditions there is provided in accordance with my invention supplementary opening means generally indicated at 6. Such supplementary opening means may comprise any suitable high speed motive means. I have chosen to illustrate the motive means for supplementing the opening spring 44 under abnormal conditions as comprising a gunpowder mechanism including a cylinder 47 and a piston 48 reciprocally mounted in cylinder 47. Adjacent one end of cylinder 47 is a sliding breech 49 wherein a suitable cartridge 55 may be inserted. The gunpowder booster mechanism is schematically illustrated in the drawing and it might well comprise a gunpowder mechanism of the type disclosed and claimed in copending Bush et a1. application Serial No. 613,504, filed concurrently with the present application and assigned to the same assignee as the present invention. The cartridge 5% preferably contains a slow-burning smokeless powder with suitable means for igniting the powder. Also included in the gunpowder mechanism 46 is a suitable firing pin 5i which is biased into the firing position by means of a spring A suitable latch 53 biased into the latching position by gravity or suitable spring means normally holds firing pin 5| in readiness to fire cartridge Suitable manual meansSd may be provided to reset the firing pin after operation thereof.

It is desirable that suitable means be provided to initiate operation of the supplemental opening means 43 when it is needed. In order to actuate firing pin iii in response to an excessive fault condition so that high speed opening of circuit breaker l is caused under such conditions, a trip coil 55 is provided having a plunger 56 for engaging latch 53. Trip coil 55 is connected to a source of suitable control potential through contacts 57 which are adapted to be controlled by a normally open switch 58 associated-with an electro-responsive device 59. The winding of electro-responsive device 59 is connected to the secondary winding 59 of a suitable current gized sufficiently to cause switch 58 to bridge whereupon trip coil 55 actuates contacts 51 plunger 5% to release firing pin latch 53 with the consequent firing of cartridge '50 and actuation of plunger 48.

As illustrated in Fig. 1, the cylinder 41 is preferably pivotally mounted as indicatedat 5| to housing I4 and the piston 48 is pivotally connected as indicated at B2 to a crank 63 pivotally mounted on pivot 35 for trip latch 34. Crank 63 is provided with an arm 64 which engages a pin 65 on trip latch 34. Initial movement of piston 48 causes counter-clockwise rotation of trip latch 34 by virtue of the fact-that arm 64 of crank 63 rotates to brush trip latch 34 out of its restraining position with reference to roller 38. Continued downward movement of piston 38 furthermore causes arm 66 of crank 63 to engage trip latch roller 39 and positively push it in a direction to cause high speed opening of circuit breaker In view of the detailed'descrjiption included above the operation of the operating means of my invention will be obvious to those skilled in the art. In the event of an abnormal current condition particularly when it is possible that the normal opening means may not be capable of satisfactorily opening the circuit breaker, supplemental opening mechanism as is rendered effective to not only operate trip latch 34 faster than it could be operated by trip coil 38, but furthermore to positively move the operating mechanism in a manner to cause high speed opening of circuit breaker l,

Although the gunpowder mechanism which provides the supplemental opening means is illustrated as a single-shot device, it will be obvious that a cartridge magazine could be employed in a manner such as is disclosed in Read Patent 723,183, assigned to the same assignee as the present application.

While I have shown and described a particular embodiment of my invention, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from my invention in its broader aspects and I, therefore, aim in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of my invention.

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

1. In an operating mechanism for an electric circuit breaker, a force transmitting linkage, motive means for actuating said breaker to the closed position through said linkage, energy storage means for opening said circuit breaker adapted to be charged by said motive means during the closing operation of said circuit breaker, means for latching said circuit breaker in the closed position and for holding said energy storage means in the charged condition, means for releasing said latching means to permit said energy storage means to open said circuit breaker, a supplemental opening means for releasing said latching means and then exerting an opening effect directly through said linkage, and means responsive to an abnormal current condition on the circuit associated with said circuit breaker for actuating said supplemental opening means to cause high speed release of said latching means and opening of said circuit breaker.

2. In an operating mechanism for an electric circuit breaker, a force transmitting linkage, motive means for actuating said breaker to the closed position through said linkage, energy storage means for opening said circuit breaker adapted to be charged by said motive means during the closing operation of said circuit breaker, means for latching said circuit breaker in the closed position and for holding said energy storage means in the charged condition, means for releasing said latching means to permit said energy storage means to open said circuit breaker, a supplemental opening means comprising a gunpowder mechanism, and means responsive to an abnormal current condition on the circuit associated with said circuit breaker for actuating said supplemental opening means to cause high speed release of said latching means and opening of said circuit breaker.

3. In an operating mechanism for an electric circuit breaker, a force transmitting linkage, motive means for actuating said breaker to the closed position through said linkage, energy storage means for opening said circuit breaker adapted to be charged by said motive means during the closing operation of said circuit breaker,

means for latching said circuit breaker in the closed position and for holding said energy storage means in the charged condition, means for releasing said latching means to permit said energy storage means to open said circuit breaker, a supplemental opening means comprising a gunpowder mechanism including a movable breech, a cartridg arranged to be positioned in said breech, a plunger adapted to be actuated upon firing of said cartridge, means responsive to an abnormal current condition on the circuit associated with said circuit breaker for firing said cartridge, and means responsive to movement of said plunger for releasing said latching means at high speed and moving said circuit breaker to the open position.

4. In an operating mechanism for an electric circuit breaker, a force transmitting linkage, motive means for actuating said breaker to the closed position through said linkage, energy storage means for opening said circuit breaker adapted to be charged by said motive means during the closing operation of said circuit breaker, means for latching said circuit breaker in the closed position and for holding said energy storage means in the charged condition, means for releasing said latching means to permit said energy storage means to open said circuit breaker, a supplemental opening means comprising a pivotally mounted gunpowder mechanism including a movable breech, a cartridge arranged to be positioned in said breech, a plunger positioned so as to be actuated upon firing of said cartridge, means responsive to an abnormal current condition on the circuit associated with said circuit breaker for firing cartridge, and means responsive to movement of said plunger for releasing said latching means at high speed and moving said circuit breaker to the open position.

5. In an operating mechanism for an electric circuit breaker, a force transmitting linkage, motive means for actuating said breaker to the closed position through said linkage, energy storage means for opening said circuit breaker adapted to be charged by said motive means during the closing operation of said circuit breaker, means for latching said circuit breaker in the closed position and for holding said energy storage means in the charged condition, means for releasing said latching means to permit said energy storage means to open said circuit breaker, a supplemental opening means comprising a gunpowder mechanism including a movable breech, a cartridge arranged to be positioned in said breech, a firing pin for said cartridge, a plunger positioned so as to be actuated upon firing of said cartridge, means responsive to an abnormal current condition on the circuit associated with said circuit breaker for actuating said firing pin, and means responsive to movement of said plunger for positively releasing said latching means at high speed and moving said circuit breaker to the open position.

RALPH R. BUSH.

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

UNITED STATES PATENTS Number Name Date 2,270,353 Spurck Jan. 20, 1942 2,319,645 Thumim May 18, 1943