US2379729A - Electric cutout - Google Patents

Description

G. F. LINCKS ELECTRIC CUTOUT July 3, 1945.

Filed April 16, 1941 Imventorfi His Attorney.

8 K c .m L F @T b c e G Patented July 3, 1945 General Electric Com New York Application April lid, ii

The present invention relates to electric circuit breakers and more particularly to such circuit breakers which may be used interchangeably with conventional fuse cutout devices.

cutout devic used to rue in therprotection of h ten or Devices at this general housing, usually parcel a pair of spaced line terminals therein and a fusible ele merit enclosed within a suitable holder mounted on the inside of the housing cover and movable into a circuit completing relation with the line terminals. The fusible element must be replaced each time one is blown by an excess cor-rent condition occurring on the circuit protected by the device. Although recent experimentation and extent its.

- research have reduced the cost of the replaceable elements, nevertheless such cost is appreciable while the servicing charges are relatively high. This is due to the fact that considerable time is consumed by a lineman in reaching the location coupled with the necessity for his hav ing with him just the right fuse limit for every individual and diilerent requirement so that the coordination of the protective system might be maintained. It is desirable to provide a tuseless cutout which will automatically interrupt the cir cult under abnormal electrical conditions and without necessitating replacement of elements after the protective operation 01' such cutouts, as in the case of fuse cutouts of the prior art. It is preferred that the electric circuit breaker be of the automatic reclosing type with means proprovide a new and improved circuit breaker of an automatic reclosing type which may be substituted for the conventional fuse type cutout.

Another object of the present invention is to.

providea fusele'ss cutout assembly, preferably of the reclosing type, mounted upon a. cover which is adapted to be pivotally attached to an insulating housing. g

Itjs another object of my invention to provide 'a. new and improved fuseless cutout which is simple and compact and which may be readily installed in an existing insulating casing provided for a. fuse typeof cutout device. v

Further objects and advantages of the invenparty, a corporation of Serial No. 388,864

till.

' the inner surface of the insulating door or cover 19 for the housing is adapted to be moved into ticn will become apparent as the following description proceeds and. the features of novelty whicw characterize my invention will be pointed out with greater particularity'in the claimsan ironed to and forming a part of this specification.

integrally formed electric creepage and gas bar- I rier ll disposed between stationary line terminal contacts 92 and ill secured in the housing. Connectors ill and iii are provided for securing to the contacts l2 and iii, respectively, the ends of conductors brought through adjacent openings the housing side walls. To the rear of the housing it is fastened a mounting bar it for the attachment oi the device to an electric line pole, crossarm structure, or the lllreu Secured in the lower portion or the housing ill is a pair of braclr et members it connected together by a transversely. extending pin it upon which the circuit breaker unit or" the present invention comprising a cover it and a circuit breaker mechanism ata. housing structure as described above is further described in the Patent No. 2,081,813, issued May 25, '1937, to Mr. Benjamin R. Hermann, and

assigned to the General Electric Company, the assignee' of the present application.

The circuit breaker mechanism mounted upon and out of operative position relative to the housingcontacts I2 and- I3 by pivotal movement of the cover about the pin l8 through means of the manual operating handle 2 I. The circuitbreaker mechanism includes an upper terminal 22 which is secured to the. upper end of the cover l9 as by screws 23 and which' in the closed ppsition of thecover is adapted to engage with the spring fingers of the line contact l2. The terminal 22 is connected by a conductor 24 with a series coil 25 which is secured by the non-magnetic sleeve 26 to an upstanding insulating portion 21 integral of the series coil is connected by means ot a flexible conductor 29 with a movable circuit breaker contact member 30. The contact member 88 is normally biased away from the series coil 28 by a compression spring 3| arranged therebetween and is adapted to be moved upwardly upon the occurrence of a predetermined current condition through the coil 25 by a magnetic armature bolt 32 the upper end of which is slidably arranged within the sleeve 28 and the lower end of which is threaded into the upper portion of the contact member 30. Arranged loosely around the armature bolt 32 is a magnetic hammer sleeve 33 which is somewhat shorter than the bolt 32. Upon a predetermined overcurrent condition the hammer sleeve 33 will be pulled upwardly and will strike against the head at the upper end of the armature bolt 32 and snap the contact member an upwardly with a quick action against the force of the biasing spring 3i The contact member is provided with an annular depending rim which is adapted to cooperatively engage with a similar annular shoulder of a tubular lower stationary contact mem-- ber 35. The stationary contact member 35 is secured by means of screws 38 to the hook arms 28 and from which the electrical circuit is completed to the lower housing contact I! by means of the spring finger 31. Centrally threaded in the upper contact member 30 and depending therefrom is ashort rod 38 of gas producing material, such as horn fiber, and which is adapted to extend into a cooperating central opening in the lower stationary contact 35. Threaded onto the outer cylindrical surface of the contact member III is a tube ll of a gas producing material, such as horn fiber, which surrounds the lower fixed contact 35 in a spaced relation so as to be freely movable relative thereto. The lower endof the tube II is slotted, as indicated at 42, for cooperatively straddling the screws 38 securing the lower contact 35 to the arms 28.

When the contacts 38 and 85 are separated by an overcurrent, an arc will be formed between the arcing tips and, due to the high temperature thereof, gas will be produced from the surfaces of the rod 38 and the tubular member ll. The turbulence of this gas pressure and the expulsion of it through the stationary contact will cause the arc to be forced downwardly through the opening in the upper end of the stationary contact, thus lengthening it and materially aidmg in increasing the-resistivity of the arc path either prior to or at the current zero. It will be observed that the rod 38 of gas producing material depending from the upper contact 88 substantially closes the upper end of the bore through the stationary contact in the closed position of the contacts and throughout a certain period of the opening operation thereof. Thus following the initial separation of the two contacts and with the vent opening through the upper end of the stationary contact 35 substantially closed, the gas pressure will be increased within the chamber formed between the two contacts. As the upper contact is moved farther away from the stationary contact and the rod 88 withdrawn from the opening of the lower contact, the pent-up gases will be suddenly released to facilitate the interruption of the are. This action is particularly effective for interrupting arcs of lower current values.

Means are provided for delaying the reclosure of the arcing contacts following the extinguishment of the arc therebetween. A timing mechanism ml, which may be of the escapement or any other well known type, is mounted upon the arms 20 through an insulator W. A control lever 46 of the timing mechanism is secured to the upper contact member 88 through an insulating arm 4i. The lever is freely movable upwardly so as to present no appreciable drag upon the contact connected thereto as it is raised by coil 25. Lowering movement of the contact is delayed by action of the mechanism 1 until it reaches a predetermined position at which time the mechanism releases the lever 16 and the spring and gravity quickly close the contacts. If the fault persists, the contacts will reopen and after a predetermined number of such opening operations will be locked out by the mechanism M. if, however, the fault is temporary, the reclosing of the contacts will permit the timing mechanism to slowly work back to a reset position, ready for the predetermined number of reclosures for which the device was originally set. While numerous suitable timing mechanisms are available which operate with the characteristics as outlined above, I prefer to use one constructed in accordance with that disclosed in the Patent No. 2,069,082, issued January 26, 1937, to Ludwig S. Walle and assigned to the General Electric Company, the assignee of the present application.

For indicating the opened condition of the circuit breaker, particularly when the contacts have been locked open by the mechanism 44, a flag indicator BI is pivoted upon a pin 52 extending between the cars 53 depending from the arms 2|). An extension 54 of the indicator is adapted to be engaged by the lower end of the insulating tube H in the closed position of the circuit breaker contacts to hold the flag indicator M in the upper position as shown. Upon the opening of the circuit breaker and upward movement of the tube 4|, the indicator will be released for downward movement either by action of gravity or by a small spring suitably arranged on the pivot pin 52.

After the circuit breaker has been locked in the open circuit position by operation of the mechanism 44, the mechanism may be reset following the clearance of the fault by simply opening the door of the cutout and then again reclosing it. The spring finger 81 completing the circuit between the lower circuit breaker contact 35 and the contact I! in the cutout housing is connected by means of an insulating rod 55 to the reset lever 51 of the timing mechanism 44. Upon opening of the cutout cover the upper end of the springfinger 31 will tend to move away from the timing mechanism 44, and through the connecting rod 58 will exert a pull on the reset lever 51 to rotate it in the counterclockwise direction against the stop 58. Such a movement of the reset lever will release the timer rod 48 and permit movement of the circuit breaker contact III to the closed position under the action of the spring 8i. By closure of the cover is the spring finger 31 will be pushed back toward the timing mechanism I4 and release the reset lever 51 to permit it to return to its initial position.

It will be apparent that the circuit breaker described is a relatively simple structure, comprising iew parts arranged in a compact manner. The unit comprising the door and circuit breaker mechanism may be hooked into an insulating housing of a conventional fuse cutout without requiring any alterations of the housing or mounting thereof. The circuit breaker does not require the replacement of any parts iollowins a protective operation and since a high percentage of .faults are temporary in nature, the service is restored in such instances by automatic reclosurei If the device locks out during a continuing fault, it may be reset readily by any common switch stick and hence the servicing operation, when necessary, is reduced to one of'virtually fool proof nature.

Having described the principle of operation of my invention in what I consider to represent a preferred embodiment thereof, I desire to have it understood that the specific arrangement shown is merely illustrative and that the invention may be carried out by other means.

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

1. A circuit interrupter comprising an insulating support having a pair of spaced contacts mounted thereon, an insulating member, removably pivoted on said support, an electric circuit breaker unit mounted. on said member and having a pair of terminals adapted to engage with said spaced contacts, said circuit breaker unit including a pair of arcing contacts and an electromagnetic coil connected in series between said terminals, means for effecting the reclosure of said arcing contacts following the opening thereof by said coil, means for delaying the reclosure of said arcing contacts and for locking said arcing contacts in a predetermined position after a predetermined number oi. successive reclosures, and means responsive to movement of said member away from said support for effecting the release of said means iorlocking said arcing contacts in said predetermined position.

2. In an electric circuit interrupter, an insulating support, a pair of spaced contacts mounted on said support, an electric circuit breaker unit hingedly mounted on said support having terminals movable into engagement with said spaced contacts, said circuit breaker unit including a pair of relatively movable arcing contacts, means normally biasing said arcing contacts to a closed circuit position, means for moving said arcing contacts to an open circuit position, means for locking said arcing contacts in an open circuit position, and means responsive to predetermined movement of said circuit breaker on said support for effecting the release of said locking means.

3. An electric circuit interrupter comprising the combination of an insulating support, a pair of spaced contacts mounted on said support, a reclosing circuit breaker unit pivotally mounted on said support, said circuit breaker unit including a pair of terminals movable into engagement with said spaced contacts, said circuit breaker um't including a pair of arcing contacts normally biased to a closed circuit position and means connected in series with said arcing contacts and said circuit breaker terminals for effecting an opening movement of said arcing contacts, means responsive to a plurality of successive reclosing operations for locking said arcing contacts in the open circuit position, and means responsive tov pivotal movement of said circuit breaker on said support for eifecting the release of said arcing contacts.

4. A circuit interrupter comprising an insulating support having a pair of spaced contactsmounted thereon, an insulating member removably pivoted on said support, an electric circuit breaker unit mounted on said member and having a pair of terminals adapted to engage with said spaced contacts, said circuit breaker unit including a pair of arcing contacts and an electromagnetic coil connected in series between said terminals, means for effecting the reclosure of said arcing contacts following the opening thereof by said coil, means for delaying the reclosure of said arcing contacts and for locking said arcing contacts open after a predetermined number of successive reclosures, and means responsive to movement of said member away from said support for effecting the release of the locked open arcing contacts.

5. A circuit breaking device comprising an insulating casing having a pair of spaced contacts mounted therein, an insulating cover for said casing removably pivoted thereon, an electric circuit breaker unit mounted on the inner surface of said cover and having a pair of terminals adapted to engage with said spaced contacts in the closed position of said cover, said cirbuit breaker unit including a pair of arcing contacts and an electromagnetic coil connected in series between said terminals, means for effecting the reclosure of said arcing contacts following the opening thereof by said coil, means for delaying the reclosu're of said arcing contacts and for locking said arcing contacts open after a predetermined number of successive reclcsures, and means responsive to the opening ofsaid cover for effecting the release of the locked open arcing contacts.

6. In a reclosing electric circuit breaker unit adapted to be removably supported in an electric cutout casing, the combination comprising a pair of arcing contacts, means for effecting relative separation of said contacts, means biasing said contacts to a closed circuit position, means for delaying the reclosure of said contacts following separation thereof and for locking said contacts open after a predetermined number ofreclosures, and means responsive to movement of said unit away from said casing for eifecting the resetting of said contacts.

7. In a reclosing circuit "breaker unit adapted to be removably supported in an electric cutout casing of substantially the size and type so as to be adapted for use as the housing for a fuse cutout and having a pair of spaced contacts therein, the combination of a. cover, a reclosing circuit breaker mechanism mounted on said cover, terminals for said circuit breaker mechanism arranged so as to engage with said contacts in the closed position of said cover, said mechanism ineluding a pair of relatively separable arcing contacts, current responsive means for effecting separation of said arcing contacts, means for eifecting the reclosure of. said arcing contacts following the separation thereof, means for locking said arcing contacts in the separated position following a predetermined number of successive reclosures, and means responsive to the movement of said cover away from said casing for effecting the resetting of said arcing contacts.

8. In an electric circuit interrupter, an insulating support, a pair of spaced contacts mounted on said support, an electric circuit breaker unit hingedly mounted on said support having terminals movable into engagement with said spaced contacts, said circuit breaker unit including a pair of relatively movable arcing contacts, means normally biasing said arcing contacts to a closed circuit position, means for moving said arcing contacts to an open circuit position, means for locking said arcing contacts in a predetermined position, and means responsive to predetermined movement of said circuit breaker for effecting the release of said locking means.

GEORGE F. LINOKS.

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