US3493952A - Electric circuit breaker with contact condition indicator - Google Patents

Electric circuit breaker with contact condition indicator Download PDF

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Publication number
US3493952A
US3493952A US570486A US3493952DA US3493952A US 3493952 A US3493952 A US 3493952A US 570486 A US570486 A US 570486A US 3493952D A US3493952D A US 3493952DA US 3493952 A US3493952 A US 3493952A
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United States
Prior art keywords
switch
circuit
rod
movable
actuating
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Expired - Lifetime
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US570486A
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English (en)
Inventor
William H Jette
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General Electric Co
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General Electric Co
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/60—Switches wherein the means for extinguishing or preventing the arc do not include separate means for obtaining or increasing flow of arc-extinguishing fluid
    • H01H33/66—Vacuum switches
    • H01H33/666—Operating arrangements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/60—Switches wherein the means for extinguishing or preventing the arc do not include separate means for obtaining or increasing flow of arc-extinguishing fluid
    • H01H33/66—Vacuum switches
    • H01H33/668—Means for obtaining or monitoring the vacuum
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H3/00—Mechanisms for operating contacts
    • H01H3/32—Driving mechanisms, i.e. for transmitting driving force to the contacts
    • H01H3/48—Driving mechanisms, i.e. for transmitting driving force to the contacts using lost-motion device
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
    • H01H9/0066—Auxiliary contact devices

Definitions

  • ABSTRACT OF THE DISCLOSURE Detection and indicating means are described for response to loss of normal contact bias in a biased closed electric circuit interrupter, as by loss of vacuum in a vacuum-type interrupter.
  • a movable switch member positively coupled to the movable contact is connected by a lost-motion coupling to an actuating mechanism.
  • Means are provided to move the switch member toward its circuit-opening position independently of the actuating mechanism upon loss of normal closing bias, and an indicator is actuated by such independent movement.
  • a typical vacuum type circuit interrupter comprises a highly evacuated envelope and a pair of relatively movable contacts located within the envelope. When the interrupter is in closed position the contacts are engaged and are thus capable of carrying current through the interrupter. Circuit interruption is effected by separating the contacts to draw an arc therebetween, soon after which the arc is extinguished and prevented from reigniting by the action of the vacuum. To assure that the arc will be extinguished and prevented from reigniting it is important that the pressure inside the envelope be maintained below a predetermined value.
  • It is particularly important to prevent leakage into the evacuated envelope (and consequent loss of vacuum) where the interrupting device is to be located under oil or other ambient liquid.
  • a vacuum leak sufficient to admit liquid to the envelope will result not only in failure to interrupt an are but may also result in destructive internal pressures due to overheating of the admitted liquid.
  • Pressure changes due to loss of vacuum or other defective contact condition may be reflected in reversely initiated actuation of the contact operating mechanism, and it is one object of my invention to utilize such reversely initiated actuation to monitor contact condition in an electric circuit breaker. It will be evident to those skilled in the art that while my invention is especially adapted to monitoring loss of vacuum in a vacuum type electric circuit interrupter it is applicable also to the monitoring of contact condition in other circuit breakers where reversely initiated contact actuaton results from some defective contact condition.
  • a specific object of my invention is to provide simple and reliable mechanical signal means responsive to reversely initiated contact movement for indicating loss of vacuum in a vacuum type electric circuit interrupter.
  • I employ a vacuum type circuit interrupting device having a movable electrode biased to one operative position by means responsive to differential pressure within and without the evacuated envelope.
  • Actuating mechanism for the movable electrode includes a lost-motion connection and an indicating member movably latched in position on one actuating member of the mechanism. The indicating member is arranged to be released for movement to a fault indicating position only in response to such relative movement at the lost-motion connection as results from contact movement reversely initiated by loss of differential pressure bias on the moving electrode.
  • FIG. 1 is a diagrammatic representation of a circuit breaker embodying my invention showing the circuit breaker actuating mechanism in cross section with the fault indicating device in normal operating position, and
  • FIG. 2 is a fragmentary representation of the same embodiment of the invention shown at FIG. 1 but with the fault indicator shown in tripped position.
  • a vacuum type electric circuit interrupting device 10 comprising an evcuated envelope 11 having at one end a deformable wall portion shown as a reentrantly positioned metallic bellows 12.
  • a pair of relatively movable cooperating switch contacts are positioned within the envelope 11 and comprise a fixed contact member 13 and a slidably movable contact member 14 actuable into and out of engagement with the contact 13.
  • the movable inner end of the bellows 12 is connected in sealing relation with the contact 14 as indicated at 15.
  • the actuating mechanism for the movable contact member 14 as illustrated in the drawing comprises a pair of axially aligned slidable rods 16 and 17 having a lost-motion coupling therebetween indicated generally as 18.
  • the switch actuating member or rod 17 is arranged to be driven from circuit opening to circuit closing position by a motor-driven operating cam 19 and a latch 20 is provided to retain the actuating rod 17 in its circuit closing position.
  • a solenoid 21 is shown for releasing the latch 20.
  • the operatng cam 19 is driven by a motor 22 energized from a suitable source of control power through a normally open control switch 23 which for the purpose of illustration is shown as manually operable.
  • the switch actuating rod 17 is strongly biased toward its circuit opening positon by means of an actuating compression spring 24 positioned between a shoulder 25 on the rod 17 and a suitable fixed support or frame portion 26.
  • the switch operating rod 17 is loosely connected to a movable switch member shown as an axially aligned slidable hollow rod or shaft 16.
  • the movable switch rod 16 is slidably mounted in the frame portion 26 and is positively connected to the movable contact member 14 by means of a bell crank 27.
  • the lost-motion connection 18' is illustrated as a cage-like head portion 30 on the upper end of the switch actuating rod 17 in cooperation with a shoulder or flange 31 at the lower end of the switch 3 rod 16. The shoulder 31 is positioned within the cage 30 for limited relative movement within the cage.
  • the movable switch member 16 and the positively connected movable contact member 14 are biased toward circuit closing position by reason of the differential pressure exerted upon the expansible bellows 12.
  • This differential pressure arises by reason of the fact that the fixed end of the bellows which is sealed to the envelope 11 at a point 32 is open to the ambient fluid surrounding the vacuum interrupting device so that the bellows is pressed inwardly by the differential pressure within and without the envelope 11.
  • Opposing the closing bias of the bellows 12 I have shown an oppositely acting compression spring 33 acting between the frame bracket 26 and the head 31 of the switch member 16.
  • the spring 33 is normally overcome by the biasing force of the bellows 12 so that the net bias of the switch member 16 and movable contact 14 is in the contact-closing direction.
  • the opposing compression spring 33 acts only as a push-off spring to ensure that the moving contact 14 moves to open circuit position in the event that the differential pressure bias of the bellows 12 is diminished by some predetermined amount.
  • the mode of operation of the foregoing switch actuating mechanism may be described as follows. Referring to FIG. 1, it will be observed that the circuit breaker is there shown in circuit closing position with the swtch actuating member 17 shown latched up against the bias of the actuating spring 24.
  • the latch 20 is released by energization by the trip solenoid 21 the actuating rod 17 moves vertically downward under action of the spring 24 and after a limited amount of lost motion in the connection 18, the cage engages the shoulder 31 of the movable switch rod 16. Thereafter the switch rod 16 and positively connected movable contact 14 are constrained to follow the spring actuated downward movement of the actuating member 17 thereby to separate the contacts 13 and 14.
  • the actuating mechanism illustrated provides for automatic separation at the contacts 13 and 14 in the event that vacuum is lost (i.e., internal pressure increases) in the envelope 11 by a predetermined amount.
  • This predetermined amount is determined by the point at which the differential pressure bias of the bellows 12, as it is diminished by loss of vacuum, is overcome by the opposing force of the push-off spring 33. At this point the moving contact 14 will move to open circuit position under the reverse bias force exerted by the spring 33.
  • the signalling means illustrated comprises a cylindrical cap 40 movably mounted upon the upper end of the hollow switch rod 16 and biased for movement to an extended position relative to the rod 16 by means of a compression spring 41 interposed between the upper end of the rod 16 and the outer end of the cap 40.
  • the indicating cap 40 is latched against its bias in a normal operating position shown at FIG. 1 by means of a pair of diametrically opposite movable ball detents-42 which are positioned in holes in the upper end of the hollow rod 16 and cooperable with normally aligned internal recesses, shown as holes 43, in the cap 40.
  • the detent balls 42 are normally retained in radially extended position engaging the cap 40 by means of a retainer plug 44 positioned in the upper end of the hollow switch member 16.
  • the retainer plug 44 is enlarged at its upper end and this upper end fits into an end portion of the rod 16 having an enlarged internal diameter.
  • the retainer plug 44 can move into the hollow switch rod 16 only to the limited extent shown at FIG. 1 but is free to move axially outward (i.e., upward as shown in the drawing) with respect to the switch rod 16. If the retainer 44 is so moved axially outward with respect to the end of the hollow rod 16 the detent balls are free to move radially inward against the smaller diameter lower portion of the retainer 44 in the manner shown at FIG. 2. By such inward movement the detent balls release the indicating cap 40 for upward movement under the bias of its spring 41.
  • the detent retainer plug 44 described above moves upwardly and downwardly as an integral part of the movable switch member 16 and thus retains the indicating cap 40 in fixed position in respect to the switch member 16.
  • Means are provided, however, for moving the retaner plug 44 upward with respect to the switch rod 16 and thus releasing the indicating cap 40 in the event that the switch member 16 is moved downwardly independently of the switch actuating member 17.
  • the actuator for the retainer plug 44 is an axial interference pin 45 engaging the retainer 44 at its lower end by means of a shoulder 46 and extending downwardly through the center of the hollow switch rod 16 into engagement with the switch actuating member 17. As illustrated at FIG.
  • Release of the indicating cap 40 may be utilized at any desired manner to indicate loss of vacuum in the device or to actuate appropriate signalling or control devices.
  • the switch 50 includes a normally open contact 52 connected in series circuit relation with a suitable alarm device, such as a bell 53, so that when the switch 52 is closed upon release of the indicating cap the alarm device 53 is also actuated.
  • the switch 50 is provided also with a normally closed contact 54 connected in series circuit relation with the closing motor 22. When the indicating cap is released the contact 54 will be opened thereby to disable the motor 22 and prevent any subsequent closing movement of the actuating rod 17.
  • a pair of relatively movable cooperating switch contacts biased to a circuitclosing position a movable switch member positlvely connected to at least one of said contacts and having circuit-opening and circuit-closing positions, actuating means loosely coupled to said switch member to provide lost motion therebetween, means responsive to a predetermined defective condition of said contacts to move said switch member toward its circuit-opening position independently of said actuating means, and signal means responsive to said independent movement of said switch member.
  • a circuit breaker according to claim 1 wherein said signal means comprises a signal member movably mounted on said switch member, and means responsive to said independent movement to move said signal member relative to said switch member.
  • a circuit breaker according to claim 2 wherein said signal member is biased to a fault indicating position and normally latched against its bias in a normal operating position and wherein said means responsive to independent movement of said switch member includes latch releasing means.
  • a circuit breaker according to claim 1 wherein said signal means comprises a signal member movably mounted on said switch member and biased to a fault indicating position, latch mean-s for holding said signal member against its bias in a normal operating position, means responsive to circuit-opening movement of said switch member to release said latch means, and means responsive to simultaneous circuit-opening movement of said switch actuating member for disabling said latch releasing means.
  • an electric circuit interrupter of the vacuum interrupting type an evacuated envelope, a pair of relatively movable cooperating switch contacts mounted in said envelope, means responsive to differential pressure within and without said envelope for biasing said contacts to circuit-closing position, a movable switch member positively connected to move said contacts between open and closed circuit position, said switch member having corresponding open and closed circuit positions, a switch actuating member loosely connected to said movable switch member to provide lost motion therebetween, said movable switch member being movable away from its circuit-closing position independently of said switch actuating member, means operable upon significant decrease in said differential pressure effect independent circuit opening movement of said movable switch member, and signal means responsive to said independent circuitopening movement.
  • a circuit breaker according to claim 5 wherein said signal means comprises a signal member movably mounted on said movable switch member and biased to a fault indicating position, latch means for holding said signal member against its bias in a normal operating position relative to said movable switch member, and latch-releasing means responsive to said independent circuit opening movement of said movable switch member.
  • a circuit breaker according to claim 6 in which said latch releasing means comprises a member movable relative to said movable switch member and positioned to be operatively engaged by said actuating member upon said independent circuit opening movement of said movable switch member.
  • An electric circuit breaker according to claim 8 wherein said movable switch rod is hollow and in axial alignment with said actuating rod, adjacent ends of said rods are connected through a lost-motion coupling, said indicating member and latch means are mounted on the remote of said end of said switch rod, and said interference member extends from said latch means through said hollow switch rod to operatively engage said actuating rod upon abnormal relative movement of said rods.
  • a circuit breaker according to claim 9 wherein said contacts are mounted in an evacuated envelope having a deformable wall portion sealed to said movable contact, differential pressure on said wall portion biasing said contacts to circuit closing position, and a push-off spring is provided to oppose but not normally overcome such differential pressure bias, said push-off spring being effective upon predetermined loss of vacuum in said envelope to move said movable contact to circuit-opening position independently of said actuating member.

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  • Measuring Fluid Pressure (AREA)
  • Driving Mechanisms And Operating Circuits Of Arc-Extinguishing High-Tension Switches (AREA)
US570486A 1966-08-05 1966-08-05 Electric circuit breaker with contact condition indicator Expired - Lifetime US3493952A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US57048666A 1966-08-05 1966-08-05

Publications (1)

Publication Number Publication Date
US3493952A true US3493952A (en) 1970-02-03

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Application Number Title Priority Date Filing Date
US570486A Expired - Lifetime US3493952A (en) 1966-08-05 1966-08-05 Electric circuit breaker with contact condition indicator

Country Status (6)

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US (1) US3493952A (de)
JP (1) JPS4535103B1 (de)
AT (1) AT279716B (de)
BR (1) BR6790976D0 (de)
CH (2) CH470745A (de)
GB (1) GB1187446A (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3775658A (en) * 1972-05-30 1973-11-27 Itt Capacitive fibrillation apparatus using vacuum relays
US3814885A (en) * 1973-07-11 1974-06-04 Gen Electric Method of detecting a leak in a vacuum interrupter located inside a housing containing pressurized gas
US4027125A (en) * 1975-03-17 1977-05-31 Allis-Chalmers Corporation Gas insulated circuit breaker
US4034264A (en) * 1974-04-02 1977-07-05 Siemens Aktiengesellschaft Arrangement for detecting a deficient operational capability of a vacuum switching vessel
US5552647A (en) * 1994-04-12 1996-09-03 Systems Analysis And Integration, Inc. Position-sensing device for power distribution switch

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1176202A (en) * 1909-03-27 1916-03-21 Allis Chalmers Mfg Co Circuit-controlling apparatus.
US3403297A (en) * 1966-03-17 1968-09-24 Gen Electric Vacuum-type circuit interrupter with pressure-monitoring means
US3404247A (en) * 1966-03-08 1968-10-01 Gen Electric Pressure responsive protective means for vacuum type circuit interrupters

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1176202A (en) * 1909-03-27 1916-03-21 Allis Chalmers Mfg Co Circuit-controlling apparatus.
US3404247A (en) * 1966-03-08 1968-10-01 Gen Electric Pressure responsive protective means for vacuum type circuit interrupters
US3403297A (en) * 1966-03-17 1968-09-24 Gen Electric Vacuum-type circuit interrupter with pressure-monitoring means

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3775658A (en) * 1972-05-30 1973-11-27 Itt Capacitive fibrillation apparatus using vacuum relays
US3814885A (en) * 1973-07-11 1974-06-04 Gen Electric Method of detecting a leak in a vacuum interrupter located inside a housing containing pressurized gas
US4034264A (en) * 1974-04-02 1977-07-05 Siemens Aktiengesellschaft Arrangement for detecting a deficient operational capability of a vacuum switching vessel
US4027125A (en) * 1975-03-17 1977-05-31 Allis-Chalmers Corporation Gas insulated circuit breaker
US5552647A (en) * 1994-04-12 1996-09-03 Systems Analysis And Integration, Inc. Position-sensing device for power distribution switch

Also Published As

Publication number Publication date
JPS4535103B1 (de) 1970-11-10
BR6790976D0 (pt) 1973-12-27
CH470745A (de) 1969-03-31
CH483105A (de) 1969-12-15
GB1187446A (en) 1970-04-08
AT279716B (de) 1970-03-10

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