US3366900A - Electric circuit breaker with electromagnetic means for opposing contactrepulsion forces - Google Patents

Electric circuit breaker with electromagnetic means for opposing contactrepulsion forces Download PDF

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Publication number
US3366900A
US3366900A US558008A US55800866A US3366900A US 3366900 A US3366900 A US 3366900A US 558008 A US558008 A US 558008A US 55800866 A US55800866 A US 55800866A US 3366900 A US3366900 A US 3366900A
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Prior art keywords
closing
contact
magnetic
force
conductor
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US558008A
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English (en)
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Barkan Philip
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General Electric Co
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General Electric Co
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Priority to US558008A priority Critical patent/US3366900A/en
Priority to GB22643/67A priority patent/GB1167057A/en
Priority to FR110126A priority patent/FR1529018A/fr
Priority to JP3828067A priority patent/JPS4520658B1/ja
Priority to DE19671640230 priority patent/DE1640230C3/de
Application granted granted Critical
Publication of US3366900A publication Critical patent/US3366900A/en
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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
    • H01H1/00—Contacts
    • H01H1/50—Means for increasing contact pressure, preventing vibration of contacts, holding contacts together after engagement, or biasing contacts to the open position
    • H01H1/54—Means for increasing contact pressure, preventing vibration of contacts, holding contacts together after engagement, or biasing contacts to the open position by magnetic force
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H77/00—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting
    • H01H77/02—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism
    • H01H77/10—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism with electrodynamic opening
    • H01H77/101—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism with electrodynamic opening with increasing of contact pressure by electrodynamic forces before opening

Definitions

  • This invention relates to an electric circuit breaker and, more particularly, relates to electromagnetic means for opposing the contact-repulsion forces developed when a high current flows through the circuit breaker.
  • the conductive path through the contacts of the circuit breaker is of a generally loop-shaped configuration.
  • Current flowing through this loop-shaped path produces magnetic forces tending to enlarge the loop, and these forces are usually in a direction tending to open the contacts of the breaker.
  • These magnetic opening forces vary in magnitude in accordance with the square of the current flowing through the breaker, and hence during overcurrent and short circuit current conditions, extremely high opening forces can be developed. A more detailed explanation of how these magnetic opening forces are developed is contained in my U.S. Patent 3,225,160, assigned to the assignee of the present invention.
  • An object of my invention is to provide a circuit breaker which can be closed against short circuit currents by a small and relatively weak closing mechanism and mechanism-operator.
  • Another object of my invention is to provide magnetic means which can provide a high closing force for assisting in closing the circuit breaker and holding it closed when desired, but yet does not significantly increase the force required for opening the circuit breaker when such opening is desired.
  • I provide a first contact and a second contact that is movable into and out of engagement with the first contact.
  • a substantially rigid conductor is mechanically and electrically coupled to said second contact for carrying current to and from the second contact.
  • Magnetic means 3,3663% Patented Jan. 30, 1968 comprising substantially rigid movable structure is provided for developing a magnetic closing force on said conductor which varies directly in accordance with the current through said contacts.
  • Releasable holding means holds said rigid movable structure in a predetermined first position when the contacts are engaged.
  • Contactopening means operates when the holding means is released to drive said rigid structure into engagement with said conductor, thereby transmitting contact-opening motion to said conductor.
  • Closing is initiated by driving said rigid movable structure into said predetermined first position. Until the rigid movable structure has been moved into substantially said predetermined first position, the conductor is restrained in a position where the contacts are widely separated. But upon movement of said rigid movable structure into substantially said predetermined first position, the restraint on the con ductor is removed and the conductor is driven by suitable biasing means into a position where the contacts engage. Such closing movement of the conductor is assisted by the magnetic closing force developed by said magnetic means when the contacts engage near the end of such closing movement.
  • FIG. 1 is a schematic view, partly in section, showing a circuit breaker embodying one form of my invention. In FIG. 1 the circuit breaker is shown in an open position.
  • FIG. 2 is a schematic view of the circuit breaker of FIG. 1, but with the parts thereof shown in closed position.
  • FIG. 3 is a sectional view taken along the line 3--3 of FIG. 2.
  • FIG. 4 illustrates a modified embodiment of the invention.
  • FIG. 5 illustrates another modified embodiment of the invention.
  • FIG. 1 there is shown an electric circuit breaker that comprises a pair of separable contacts 11 and 12.
  • the contact 11 is a stationary contact and the contact 12 is a movable contact that is vertically movable into and out of engagement with the stationary contact.
  • the contact 12 is shown in its fullyopen position where it is widely spaced from the contact 11. Closing of the circuit breaker is effected by driving contact 12 upward into its position of FIG. 2, where it engages contact 11.
  • the contacts 11, 12 are shown located inside a highly evacuated envelope 13 comprising a cylindrical insulating casing 14 and upper and lower end caps 8 and 15, respectively, joined thereto by vacuumtight seals 16.
  • the stationary contact 11 is mounted on a stationary conductive rod 9 that is integrally joined to the upper end cap 8.
  • the movable contact 12 is mounted on a conductive operating rod 17 that projects freely through the lower end cap 15.
  • a flexible metal bellows 18 between the lower end cap 15 and the operating rod 17 permits vertical movement of the rod 17 without impairing the vacuum inside the envelope 13.
  • a rigid conductive cross-bar 20 is rigidly attached to the conductive operating rod 17 at its lower end.
  • This conductive cross-bar 20 is pivotally mounted at one end on a stationary pivot 21 carried by the lower end cap 15.
  • a conductor 23 is suitably joined to the cross-bar 20 at its opposite end for carrying current to and from the crossbar.
  • a tension spring 24 which is connected between the conductive cross-bar and a fixed point 26, urges the cross-bar 20 in a counterclockwise closing direction.
  • the cross-bar 20 is restrained in its illustrated position by means of a releasable latch 28 which acts on a latch roller 30 carried by the cross-bar 20.
  • the latch 28 is biased into its illustrated positioned by a torsion spring 31 tending to pivot the latch counterclockwise about its stationary pivot 32.
  • latch roller 30 is released and spring 24 is free to drive crossbar 20 together with contact 12 through an upward closing stroke.
  • this U-shaped structure 40' or yoke comprises a pair of spaced-apart legs 42 and a bight portion 43 joining the legs. Between the legs 42 is an open-sided recess 44 into which the crossbar 20 moves during a closing operation.
  • This magnetizable structure 40 acts in the general manner described in the aforesaid Streater patent to provide an upward closing force on the cross-bar 20 that varies in accordance with the square of the current through the cross-bar 20.
  • current flowing through the crossbar 20 creates magnetic flux around the bar which is depicted by the lines of force 41 in FIG. 3. These lines of force follow a magnetic circuit extending through the U-shaped magnetic structure 40 and then across the air gap extending between the legs 42 of the magnetizable structure. In this magnetic curcuit, the air gap is in series with the magnetizable structure 40.
  • the cross-bar 20 is positioned in this air gap when the contact 12 is in its fully-closed position of FIGS. 2 and 3.
  • a conductor located in such an air gap will tend to move into a position wherein the reluctance of the surrounding magnetic circuit is a minimum, and thus there is a tendency for conductor 20 to move upwardly toward the bight 43 of the U-shaped structure 40.
  • the force tending to move conductor 20 toward the bight 43 varies in magnitude as a direct function of the square of the current through conductor 20.
  • increased magnetic forces are developed at magnetic structure 40 for driving the contacts fully closed and for holding them closed.
  • This magnetic force is independent of the polarity of the current flowing through conductor 20 since, irrespective of the direction of the lines of force traversing the air gap, the position of conductor 20 where the reluctance of the magnetic circuit will be a minimum is still toward the bight 43 of the U-shaped structure 40.
  • the magnitude of this magnetic force depends primarily upon the flux density of the magnetic field in the gap, and this flux density is substantially independent of the polarity of the current. In this latter regard, the low retentivity of the magnetizable material assures that the flux density will be substantially the same for a given value of current, whether such value is negative or positive.
  • the magnitude of the force urging the cross bar toward bight 43 of U-shaped structure 40 is dependent upon the width of the structure 40 (depicted at W in FIG. 2) and varies as a direct function of this width W.
  • this width W is made sufliciently large that the closing force developed at magnetic structure 40 for any given current is greater than the electromagnetic loop forces tending to force the contacts open.
  • a net force is present tending to hold the contacts closed or to drive them closed if not already fully closed.
  • This net force increases as current flowing through the contacts increases.
  • This net closing force will prevent the contacts from being blown open by the magnetic loop forces without requiring any assistance from the closing spring 24.
  • This net force simply urges contact 12 more firmly against stationary contact 11 as the current increases. It the contacts 12 and 11 are not fully closed when current is flowing through the crossbar 20, this net force will move contact 12 into full engagement with contact 11 and hold it there.
  • the magnetizable structure 40 is a movable member that is movable into its position of FIG. 2 and held in such position prior to movement of the crossbar 20 into its contact-engaged position of FIG. 2.
  • FIG. 1 shows the magnetizable structure 40 in a lowered position that it occupies when the circuit breaker is open.
  • a circuit breaker-closing operation is initiated by driving magnetizable structure 40 upwardly from its open position of FIG. 1 into its closed position of FIG. 2. This upward movement causes magnetizable structure 40 to engage and trip latch 28, thereby allowing tension spring 24 to drive cross-bar 20 and movable contact 12 into their contact-engaged position of FIG. 2, as explained hereinabove.
  • I For transmitting the above-described upward force to magnetizable structure 40, I provide an insulating operating rod 45.
  • This operating rod 45 is rigidly connected to magnetizable structure 49 by means of a U-shaped insulating yoke 46, best shown in FIG. 3.
  • the U-shaped insulating yoke 46 contains a recess 47 that aligns with the recess 44 in the magnetizable member 40.
  • Suitable connecting means (not shown) are provided for rigidly coupling parts 40 and 46 together.
  • An opening spring 48 acts on the operating rod 45 and biases it downwardly toward its position of FIG. 1.
  • Closing mechanism 50 comprises a pair of toggle links 52 and 54 pivotally joined together at a knee 55.
  • One of the toggle links 52 is pivotally connected at its opposite end to the lower end of the operating rod 45 by means of a pivot pin 56.
  • the other toggle link 54 is pivotally connected by pivot pin 58 to the upper end of a guide link 59.
  • This guide link 59 is pivotally supported at its lower end on a fixed fulcrum 60 and is biased toward its position of FIG. 1 by a suitable reset spring 60a.
  • the pivot pin 58 carries a latch roller 61 which cooperates with a suitable trip latch 62.
  • Trip latch 62 is arranged to be operated in response to predetermined circuit conditions by means of a suitable conventional tripping solenoid 64.
  • the tripping solenoid 64 is suitably connected to be operated in response to an overcurrent through the power circuit through the breaker.
  • FIG. 2 illustrates the position of the parts after knee 55 has been moved to the right to effect circuit breaker-closing.
  • This closing motion of knee 55 from it position of FIG. 1 to its position of FIG. 2 is produced by the action of a rotatable cam 70 cooperating with the usual roller 72 which is mounted at the knee 55.
  • Cam 70 has a constant radius portion 73 that holds the magnetizable structure in its extreme upward position during the final rotation of cam 70 preceding its entry into the position of FIG. 2.
  • magnetizable structure 40 when magnetizable structure 40 nears the end of its upward closing stroke, it trips latch 28, thus allowing tension spring 24 to drive crossbar 20 and movable contact 17 upwardly into their contact-engaged position of FIG. 2.
  • the magnetizable structure 4-0 has been moved through the final portion of its closing stroke and into its uppermost position of FIG. 2, where it is held by knee roller '72 resting on the constant-radius portion 73 of cam '70.
  • the magnetizable member 40 and the insulating yoke 46 that is rigidly coupled thereto may be thought of as constituting substantially rigid movable structure that is releasably held in its position of FIG. 2 by the trip latch 62 and closing cam 70 acting through linkage 50, 4.5.
  • Tripping open of the circuit breaker is effected by energizing solenoid 64 sufficiently to drive trip latch 62 clockwise about its stationary pivot 65 against the bias of a suitable reset spring 66.
  • solenoid 64 sufficiently to drive trip latch 62 clockwise about its stationary pivot 65 against the bias of a suitable reset spring 66.
  • the pivot 58 will be freed by such tripping action, thus no longer serving as a stationary reaction point for toggle 52, 54. This will render toggle 52, 54 inoperable to transmit thrust to movable operating rod 45, and as a result, opening spring 48 will be free to drive operating rod 51 downwardly into its open position.
  • magnetizable means 40 tends to hold the contacts in engagement under normal closed-circuit conditions, it does not interfere with the above-described opening and, as a matter of fact, actually aids it.
  • magnetizable means 40 tends to hold the contacts in engagement under normal closed-circuit conditions, it does not interfere with the above-described opening and, as a matter of fact, actually aids it.
  • the opening spring 48 is not required to overcome the magnetic force that holds the contacts closed. As a matter of fact, it is assisted by this force during a tripping operation. It will therefore be apparent that the opening spring 48 can be a relatively light spring. Although the opening Spring must operate against closing spring 24, this does not impose much of a burden on it since the closing spring 24 is also relatively light. In this regard, recall that the closing Spring 24, in producing closing, is not required to overcome any magnetic loop force opposing closing since the force for this latter purpose is derived from magnetizable structure 40.
  • operating mechanism 50 may also be relatively small and weak. All that is required of this mechanism 50 and its operator in terms of closing force is the ability to drive the magnetizable structure 40 from its position of FIG. 1 to its position of FIG. 2 against the opening spring 48. Since, as explained above, the opening spring can be relatively light, the mechanism 50' and its operator are called upon to overcome only a small opposing force. The mechanism 50 and its operator therefore can be small and relatively weak and inexpensive. It is to be understood, however, that mechanism 50 and operating rod 45 must have sufiicient rigidity to be able to hold the magnetizable structure 40 in its position of FIG. 2 against the magnetic closing force developed at 40 tending to move magnetizable structure 40 downward.
  • the operator (not shown) for mechanism 50 is not required to supply closing force for overcoming the usual magnetic loop force opposing closing since, as explained above, such closing force is supplied entirely by the action of magnetizable structure 40. Since the operator for mechanism 50 is relieved of overcoming these magnetic loop forces, it will be apparent that no more force is required of the mechanism operator when closing under short circuit conditions than when closing under no-load conditions. In either case, all that is required of the operator for mechanism 50 is to drive the magnetizable yoke 40 upwardly from its positon of FIG. 1 to its position of FIG. 2, and this is done before any current flows through the circuit breaker and thus without regard to any magnetic loop forces opposing closing.
  • a related advantage is that I am not required to dissipate the large excess of energy that is present in most circuit breakers when closing on light currents.
  • most circuit breakers have a powerful closing means capable of supplying all the energy needed to close against short circuit currents. When closing against low currents, there is a large amount of excess energy, unused for closing, which must be effectively dissipated to prevent damage to the circuit breaker or other harmful effects.
  • My closing means develops closing energy in direct proportion to the current, and thus there is no large amount of excess energy to dissipate when closing on light currents.
  • FIG. 4 shows a modified form of the invention, where an overcenter spring is employed instead of latch 28 of FIG. 1 in order to hold the contacts open until the magnetizable structure 40 is driven upwardly into substantially its fully-closed position.
  • This over-center spring has one end connected to the cross-bar 2t) and its other end connected to a carrier link 82 that is pivotally supported on a stationary pivot 84.
  • the connection of spring 80 to cross-bar 20 is through a pin 81, and the connection to carrier link 82 is through a pin 83.
  • the carrier link 82 is coupled to the insulating yoke 46 by means of a pin and slot connection 86, 88.
  • Pin 88 is a transverse pin fixed to the yoke 46 and received in a slot 86 in the carrier link 82.
  • FIG. 4 illustrates the parts in the fully-open position.
  • the insulating yoke 46 acting through pin and slot connection 86, 88, drives carrier link 82 in a closing direction about its stationary pivot 84.
  • spring 80 passes across a line connecting pins 21 and 81.
  • the over-center spring was urging the cross-bar 20 in a counterclockwise opening direction about pivot 21.
  • the spring 80 passes over-center, the spring acts to drive cross-bar 20 in a counter-clockwise closing direction.
  • Magnetizable structure 40 acts in the same manner as previously explained to supply the closing force to overcome any opposing magnetic loop forces that might be established when the contacts 12, 11 touch at the end of the closing operation.
  • An opening operation of the interrupter of FIG. 4 is effected in the same manner as described with respect to FIGS. 1-3. More specificially, magnetizable structure 40 is driven downwardly by an opening spring (48 of FIG. 2) to impact against cross-bar 2t) and drive the contacts apart.
  • the carrier link 82 is reset during such an opening operation by means of the pin and slot connection 86, 88. More specifically, downward motion of insulating yoke 46 is imparted through the pin 88 to carrier link 82 to drive carrier link 82 counterclockwise into its open position of FIG. 4.
  • FIG. 5 shows another embodiment of my invention.
  • the rigid conductor 20 and the hold-open latch 28 are of substantially the same construction as correspondingly-designated parts in FIGS. 1 and 2, but the magnetic closing-force-producing means is somewhat different.
  • this magnetic closingforce-producing means comprises a second rigid conductor 100 that is pivotally mounted on a stationary pivot 102.
  • This second conductor 100 is electrically connected to the first conductor 20 through flexible braid 104 connected between the free ends of rigid conductors 26 and 100.
  • a terminal conductor 23 is provided at the opposite end of conductor 1%.
  • A. closing operation is initiated by driving lower conductor 100 upwardly into a predetermined first position where it is rigidly held by closing cam 70, corresponding to cam 70 of FIGS. 1 and 2.
  • this operation is effected by force transmitted through trip-free closing mechanism 59 and an operating rod 45 suitably interconnecting mechanism 50 and conductor 1%.
  • Components 45 and 5t correspond to identically-designated components in FIGS. 1 and 2.
  • the rigid conductor 1% acts through a yoke'106 to trip the hold-open latch 28. This enables closing spring 24 to drive conductor 20 and movable contact 12 upwardly into their respective contactengaged positions.
  • the magnetic closing force for closing against high currents is derived from the interaction of the magnetic fields about conductors and 20.
  • current in traversing the U- shaped conductive path 100, 104, 28, flows through the adjacent rigid conductors 100 and 20 in opposite directions, as indicated by dotted-line arrows 107.
  • the interaction of the magnetic fields about the oppositely conducting adjacent conductors 108 and 28 produces a magnetic repulsion force that tends to separate the conductors 100 and 20. Since the lower conductor 100 is then latched in its uppermost position by the closing cam 70, this repulsion force acts on the movable conductor 20 to complete its upward closing motion and to maintain the contacts engaged.
  • this closing force is dependent upon the length of the conductors 2t) and 100 disposed to the right of contact rod 17 and varies as a direct function of this length as well as of the current then flowing through the conductors 20 and 100.
  • these conductors 20 and 100 are made sufiiciently long that the closing force developed between conductors 20 and 100 for any given current is greater than the electromagnetic loop forces tending to force the contacts open.
  • a net force is present for any given current tending to hold the contacts closed or to drive them closed if not already closed.
  • An opening operation is initiated in the embodiment of FIG. 5 by tripping the latch 62. This frees the lower conductor 100 for downward movement.
  • the conductor 100 moves rapidly downward under the bias of opening spring 48 and the additional bias of the magnetic repulsion force between conductors 20 and 100. After a predetermined amount of such downward motion, the yoke 106 strikes the upper conductor 20 to drive it downward through its contact-opening stroke.
  • the magnetic force which tended to hold the contacts engaged under normal-closed contact conditions is utilized to assist the opening operation when trip latch 62 is tripped.
  • this magnetic force drives the yoke 40 downwardly against conductor 2t
  • this magnetic force drives the yoke 1% downwardly against conductor 20. Since this magnetic force varies as a direct function of the current then flowing, it will be apparent that an opening force varying directly with current is provided. Providing an opening force that varies directly with current is desirable because the speed of contact-separation normally varies directly with the magnitude of this force. Thus, contactseparation is made to take place at higher speeds for higher currents. This relationship appears to contribute to improved interrupting performance by the interrupter.
  • This invention has particular applicability to a vacuumtype circuit breaker because under certain conditions the interrupting performance of such circuit breakers appears to be sensitive to the amount of contact pressure that is present immediately before opening. More specifically, it appears that the ability of a vacuum circuit breaker to switch predominantly-capacitive circuits is improved when the contact pressure during this interval is low. Since capacitive circuits typically involve low currents, my circuit breaker normally applies only low pressures during the interval preceding opening and thus will exhibit improved capacitance-switching ability, Despite this improved capacitance-switching ability, there is no impairment of the breakers ability to close and remain closed under high current conditions since closing force varying directly with current is developed, as was pointed out hereinabove. In the usual circuit breaker, the high force required for high currents is also present during low currents. This latter relationship, if present in a vacuum circuit breaker, appears to detract from the breakers capacitance-switching ability.
  • An electric circuit breaker comprising:
  • magnetic means comprising substantially rigid movable structure for developing a magnetic closing force on said conductor which varies directly in accordance with the current through said contacts,
  • contact-opening means operable when said holding means is released for driving said rigid structure into engagement with said rigid conductor thereby transmitting contact-opening motion to said conductor
  • closure-assisting means for rendering said restraining means inetfective following movement of said rigid movable structure substantially into said predetermined first position and for thereafter driving said rigid conductor into said closed-circuit position where said contacts are engaged.
  • circuit breaker of claim 1 in which said rigid conductor constitutes a first substantially rigid conductor and said rigid movable structure comprises a second substantially rigid conductor located adjacent said first conductor, means for connecting said first and second rigid conductors in series and for causing current to flow through said adjacent conductors in opposite directions to produce a repulsive magnetic force therebetween which constitutes at least a portion of said magnetic closing force.
  • said substantially rigid movable structure comprises a member of low retentivity magnetizable material forming a portion of the magnetic circuit for flux generated by current flowing through said conductor, said magnetizable member having a recess into which said conductor is movable to decrease the reluctance of said magnetic circuit, said conductor being positioned in said recess when said contacts are engaged, said magnetic circuit containing in series with said magnetizable member a gap in which said conductor is located when positioned in said contact-engaged position within said recess, whereby a magnetic force is then exerted on said conductor tending to hold said contacts engaged.
  • closureassisting means comprises means responsive to movement of said rigid movable structure substantially into said predetermined first position.
  • said restraining means comprises a hold-open latch for holding said conductor in said contact-separated position
  • said closure-assisting means comprises means for releasing said hold-open latch in response to movement of said rigid movable structure substantially into said predetermined first position.
  • circuit breaker of claim 1 in which said restraining means and said closure-assisting means comprise an overcenter spring that biases said conductor toward said contact-separated position during initial closing movement of said rigid movable structure toward said predetermined first position but biases said conductor toward said contact-engaged position when said rigid movable structure has moved substantially into said predetermined first position.
  • said closing means comprises a mechanically trip-free linkage coupled to said rigid movable structure; said linkage comprising a releasable latch which, when set, maintains said linkage in a condition to transmit holding force to said rigid movable structure for holding said rigid movable structure in said predetermined first position; said latch, when released, rendering said linkage inefiective to transmit said holding force to said rigid movable structure.
  • circuit breaker of claim 1 in which said circuit breaker is a vacuum-type circuit breaker comprising a highly-evacuated envelope in which said contacts are located.
  • An electric circuit breaker comprising:
  • substantially rigid movable structure including a member of low retentivity magnetizable material forming a portion of the magnetic circuit for flux generated by current flowing through said conductor, said magnetizable member having a recess into which said conductor is movable to decrease the reluctance of said magnetic circuit,
  • said magnetic circuit containing in series with said magnetizable member a gap in which said conductor is located when positioned in said contact-engaged position within said recess, whereby a magnetic force is then exerted on said conductor tending to hold said contacts engaged,
  • contact-opening means operable when said holding means is released for driving said rigid movable structure into engagement with said conductor, thereby transmitting contact-opening motion to said conductor through said rigid movable structure
  • closure-assisting means for rendering said restraining means ineffective following movement of said magnetizable member substantially into said predetermined first position and for thereafter driving said rigid conductor into said contact-engaged position within said recess.
  • An electric circuit breaker of the vacuum-type comprising:
  • opening means for substantially eliminating said magnetic closing force while current is still flowing through said contacts, thereby reducing the force required for separating said contacts

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US558008A 1966-06-16 1966-06-16 Electric circuit breaker with electromagnetic means for opposing contactrepulsion forces Expired - Lifetime US3366900A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US558008A US3366900A (en) 1966-06-16 1966-06-16 Electric circuit breaker with electromagnetic means for opposing contactrepulsion forces
GB22643/67A GB1167057A (en) 1966-06-16 1967-05-16 Improvements in Electric Circuit Breakers with Electromagnetic Means for Opposing Contact-Repulsion Forces.
FR110126A FR1529018A (fr) 1966-06-16 1967-06-13 Interrupteur électrique
JP3828067A JPS4520658B1 (fr) 1966-06-16 1967-06-16
DE19671640230 DE1640230C3 (de) 1966-06-16 1967-06-16 Den Kontaktabhebekräften entgegenwirkende elektromagnetische Einrichtung für einen Leistungsschalter

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Application Number Priority Date Filing Date Title
US558008A US3366900A (en) 1966-06-16 1966-06-16 Electric circuit breaker with electromagnetic means for opposing contactrepulsion forces

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US3366900A true US3366900A (en) 1968-01-30

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US558008A Expired - Lifetime US3366900A (en) 1966-06-16 1966-06-16 Electric circuit breaker with electromagnetic means for opposing contactrepulsion forces

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US (1) US3366900A (fr)
JP (1) JPS4520658B1 (fr)
FR (1) FR1529018A (fr)
GB (1) GB1167057A (fr)

Cited By (14)

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US3534304A (en) * 1967-11-13 1970-10-13 English Electric Co Ltd Electrical switchgear with actuating means incorporating an overcurrent trip
US3594668A (en) * 1970-01-02 1971-07-20 Texas Instruments Inc Remote control circuit breaker
US3614353A (en) * 1968-05-30 1971-10-19 Tokyo Shibaura Electric Co Switching device having electro-magnetic means for increasing effective contact pressure
US3639865A (en) * 1970-02-09 1972-02-01 Tokyo Shibaura Electric Co Circuit breaker
US3651436A (en) * 1970-01-02 1972-03-21 Texas Instruments Inc Circuit breaker
US3663906A (en) * 1969-10-09 1972-05-16 Gen Electric Electric circuit breaker with magnetically assisted closing means
US3777291A (en) * 1972-11-20 1973-12-04 Gen Electric Electric switch with magnetic-assist means to assist switch in closing and remaining closed against high currents
US4025886A (en) * 1976-06-04 1977-05-24 General Electric Company Electric circuit breaker with electro-magnetically-assisted closing means
US4030055A (en) * 1976-02-27 1977-06-14 General Electric Company Electric circuit breaker with electro-magnetic means for opposing magnetic contact-repulsion forces
US4032870A (en) * 1975-09-15 1977-06-28 General Electric Company Electric circuit breaker with electromagnetic-assist means for opposing magnetic contact-separating forces
US4099039A (en) * 1976-12-20 1978-07-04 General Electric Company Means for effectively controlling the forces imposed on the movable contact of a vacuum-type circuit interrupter
DE3200777A1 (de) * 1981-01-19 1982-09-16 Mitsubishi Denki K.K., Tokyo "unterdruck-stromkreisunterbrecher"
US5088341A (en) * 1990-02-09 1992-02-18 Westinghouse Electric Corp. Engaging lever lock for rotor turning gear
US6140894A (en) * 1996-07-05 2000-10-31 Fki Plc Electrical circuit breakers

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Publication number Priority date Publication date Assignee Title
FR2993092B1 (fr) 2012-07-03 2015-04-17 Schneider Electric Ind Sas Appareil de coupure comprenant des moyens de maintien en fermeture des contacts

Citations (4)

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US2090519A (en) * 1937-08-17 Vacuum circuit interrupter
US2601484A (en) * 1949-11-16 1952-06-24 Ite Circuit Breaker Ltd Blow open, blow closed circuit breaker
US3215797A (en) * 1961-12-28 1965-11-02 Siemens Ag Synchronous-type circuit interrupter with holding magnet for releasing latching means
US3253098A (en) * 1963-10-24 1966-05-24 Allis Chalmers Mfg Co Mechanical actuator with permanent magnet

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2090519A (en) * 1937-08-17 Vacuum circuit interrupter
US2601484A (en) * 1949-11-16 1952-06-24 Ite Circuit Breaker Ltd Blow open, blow closed circuit breaker
US3215797A (en) * 1961-12-28 1965-11-02 Siemens Ag Synchronous-type circuit interrupter with holding magnet for releasing latching means
US3253098A (en) * 1963-10-24 1966-05-24 Allis Chalmers Mfg Co Mechanical actuator with permanent magnet

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3534304A (en) * 1967-11-13 1970-10-13 English Electric Co Ltd Electrical switchgear with actuating means incorporating an overcurrent trip
US3614353A (en) * 1968-05-30 1971-10-19 Tokyo Shibaura Electric Co Switching device having electro-magnetic means for increasing effective contact pressure
US3663906A (en) * 1969-10-09 1972-05-16 Gen Electric Electric circuit breaker with magnetically assisted closing means
US3594668A (en) * 1970-01-02 1971-07-20 Texas Instruments Inc Remote control circuit breaker
US3651436A (en) * 1970-01-02 1972-03-21 Texas Instruments Inc Circuit breaker
US3639865A (en) * 1970-02-09 1972-02-01 Tokyo Shibaura Electric Co Circuit breaker
US3777291A (en) * 1972-11-20 1973-12-04 Gen Electric Electric switch with magnetic-assist means to assist switch in closing and remaining closed against high currents
US4032870A (en) * 1975-09-15 1977-06-28 General Electric Company Electric circuit breaker with electromagnetic-assist means for opposing magnetic contact-separating forces
US4030055A (en) * 1976-02-27 1977-06-14 General Electric Company Electric circuit breaker with electro-magnetic means for opposing magnetic contact-repulsion forces
US4025886A (en) * 1976-06-04 1977-05-24 General Electric Company Electric circuit breaker with electro-magnetically-assisted closing means
US4099039A (en) * 1976-12-20 1978-07-04 General Electric Company Means for effectively controlling the forces imposed on the movable contact of a vacuum-type circuit interrupter
DE3200777A1 (de) * 1981-01-19 1982-09-16 Mitsubishi Denki K.K., Tokyo "unterdruck-stromkreisunterbrecher"
US5088341A (en) * 1990-02-09 1992-02-18 Westinghouse Electric Corp. Engaging lever lock for rotor turning gear
US6140894A (en) * 1996-07-05 2000-10-31 Fki Plc Electrical circuit breakers

Also Published As

Publication number Publication date
FR1529018A (fr) 1968-06-14
GB1167057A (en) 1969-10-15
JPS4520658B1 (fr) 1970-07-14
DE1640230B2 (de) 1975-08-14
DE1640230A1 (de) 1970-05-27

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