US3639865A - Circuit breaker - Google Patents

Circuit breaker Download PDF

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Publication number
US3639865A
US3639865A US113854A US3639865DA US3639865A US 3639865 A US3639865 A US 3639865A US 113854 A US113854 A US 113854A US 3639865D A US3639865D A US 3639865DA US 3639865 A US3639865 A US 3639865A
Authority
US
United States
Prior art keywords
movable arm
circuit breaker
contact
movable
excess current
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US113854A
Other languages
English (en)
Inventor
Chuzo Takeda
Yoshihiro Kojima
Yamaguchi Toshiyuki
Yasuo Ariyama
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Corp
Original Assignee
Tokyo Shibaura Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tokyo Shibaura Electric Co Ltd filed Critical Tokyo Shibaura Electric Co Ltd
Application granted granted Critical
Publication of US3639865A publication Critical patent/US3639865A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • H01H33/02—Details
    • H01H33/28—Power arrangements internal to the switch for operating the driving mechanism
    • H01H33/30—Power arrangements internal to the switch for operating the driving mechanism using fluid actuator
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H71/00—Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
    • H01H71/10—Operating or release mechanisms
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H71/00—Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
    • H01H71/10—Operating or release mechanisms
    • H01H71/12—Automatic release mechanisms with or without manual release
    • H01H71/24—Electromagnetic mechanisms
    • H01H71/2472—Electromagnetic mechanisms with rotatable armatures
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H71/00—Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
    • H01H71/10—Operating or release mechanisms
    • H01H71/12—Automatic release mechanisms with or without manual release
    • H01H71/46—Automatic release mechanisms with or without manual release having means for operating auxiliary contacts additional to the main contacts
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H71/00—Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
    • H01H71/10—Operating or release mechanisms
    • H01H71/12—Automatic release mechanisms with or without manual release
    • H01H71/46—Automatic release mechanisms with or without manual release having means for operating auxiliary contacts additional to the main contacts
    • H01H2071/467—Automatic release mechanisms with or without manual release having means for operating auxiliary contacts additional to the main contacts with history indication, e.g. of trip and/or kind of trip, number of short circuits etc.

Definitions

  • a movable arm rotatably disposed on a second rotatably mounted arm has a contact secured to one end which detachably contacts a fixed contact to switch a circuit.
  • Means are provided for normally urging the first movable arm in a direction to separate the contacts.
  • a driving device for displacing the first movable arm and the second movably arm jointly through an engaging mechanism connected therebetween causes the contacts to engage, and another device responsive to an excess current sensing means is provided for disengaging the engaging mechanism to permit the contacts to be separated in such cases, even while the circuit breaker is being normally operated.
  • a high speed circuit breaker used in, for example, an electric train is generally operated by introducing compressed air into a cylinder through an electromagnetic valve, thereby pushing an insulation rod carried by a piston operatively disposed in the cylinder and effectively moving a movable contact member into contact with a fixed contact member.
  • an electromagnet excited by-a holding coil maintains the contact between said contact members. Accordingly, even when the insulation rod is brought back to its original position by releasing the compressed air from that side of the cylinder, the contact condition is retained. Cutoffs are classified into normal cutoffs and those made whenever excess current is realized in the circuit. Normal cutoffs are effected by demagnetizing the electromagnet. Emergency cutoffs because of excess current are usually realized because the holding force of the holding coil is extinguished by the passage of the excess current through a trip coil. Thus, the holding coil and the trip coil are differentially operated with respect to excess current.
  • a circuit breaker of the aforementioned arrangement fails to cut off excess current which happens to be introduced when the movable contact member is brought into contact with the fixed contact member by operation of the piston carrying the insulation rod, unless it is fully brought back to its original position.
  • These types of circuit breakers therefore do not ofier adequate safety provisions because of the absence of a suitable free tripping mechanism. Since the holding and trip coils are differentially operated with respect to excess current, current passing through the holding coil should have a prescribed direction. However, excess current does not always have a fixed direction. Further, the aforesaid type of circuit breaker presents difficulties in selectively indicating normal cutoffs and those of excess current.
  • the circuit breaker of the present invention which comprises a fixed contact member connected to one end of the circuit breaker through an excess current detecting coil; a first movable arm provided at one end with a movable contact member connected to the other terminal of the circuit breaker so as to close and open both terminals by detachably engaging the movable contact member with the fixed contact member; a second movable arm provided at one end with a shaft for rotatably supporting the first movable arm at an intermediate point thereof, and being rotatably supported at its other end by a fixed shaft; engagement means for jointly moving the first and second movable arms when a driving surface for the first movable arm positioned between its point of rotation and a point at which the other end of the first movable arm engages an element on the second movable arm is urged in a direction to cause the movable contact member to contact the fixed contact member; mechanisms for automatically disengaging the engagement means upon introduction of excess current; means for normally displacing the first movable arm
  • the engagement means are disengaged by an electromagnet which is excited by the passage of the excess current through a detecting coil thereof.
  • the movable member of the driving mechanism is further advanced, thereby causing the first movable arm to rotate in a direction to effect a separation of the contact members.
  • the advancement of the movable member of the driving mechanism from its one end position varies between normal cutoffs and those made in response to the detection of excess current, so that it is easily possible to individually indicate these two types of cutoffs by monitoring the different degrees of advancement by the movable member of the driving mechanism.
  • FIG. 1 illustrates, partly in section, a circuit breaker constructed according to an embodiment of the present invention wherein the contact members are shown in a separated condition;
  • FIG. 2 represents the'operating condition of the circuit breaker of FIG. 1, with some parts omitted wherein the contact members are shown in contacting relation with each other;
  • FIG. 3 illustrates the circuit breaker of FIG. 1 showing the contact members being detached from each other upon the introduction of excess current to the circuit breaker while it is in the operating condition shown in FIG. 2;
  • FIGS. 4A through 4D indicate schematic modifications of a supplementary contact mechanism which may be used in a selective indication device according to another embodiment of the invention.
  • a forked fixed contact member 1 is shown being connected to one end terminal 4 of a circuit breaker through a blow coil 2 and an excess current detection coil 3.
  • a first movable arm 5 is connected to the other end terminal 7 of the circuit breaker through a flexible conductor 6.
  • One end of the movable arm 5 is formed into a forked movable contact member 8 for switching a circuit across both terminals 4 and 7 of the circuit breaker.
  • a second movable arm 12 is rotatably mounted on a fixed shaft 10 securably inserted into a fixed support member 9.
  • a rotary shaft 13 Disposed at one end of the second movable arm 12 is a rotary shaft 13 which rotatably supports the first movable arm 5 substantially at its middle point.
  • a cam 14 having a cam surface Ma.
  • the other end of the second movable arm 12 is provided with a rotary shaft 15 on which is rotatably mounted an arm 16, normally being urged to rotate in a clockwise direction about the rotary shaft 15 by the clockwise displacing force of a spring 17.
  • the arm 16 has a roller 18 secured to one end for engaging the cam surface 14a and a projection 16a formed at an intermediate point, the purpose of which will be set forth hereinbelow.
  • a movable iron core 20 facing another iron core 19 excited by excess current passing through the de-' tection coil 3 thereof.
  • the movable iron core 20 is fixed on an arm member 23 rotatably mounted on a fixed shaft 22.
  • a projecting arm 23a of the arm member 23 is connected to a biasing spring 24 which normally urges the arm member 23 to rotate in a clockwise direction.
  • To the end of another projecting arm 23b of arm member 23 is secured a roller 25 which abuts against the projection 16a of arm 16 when the projection arm 23b is rotated in a counterclockwise direction.
  • a fixed rod 26 is provided for restricting the clockwise rotation of the rotatable arm 23 under the biasing influence of spring 24.
  • a driving mechanism which comprises a cylinder 27, a piston 29 disposed therein being normally biased by a spring 28 in a direction which permits the contact members 1 and 8 to remain separated, a movable rod member 33 connected to piston 29 having an insulated member 30 thereon and being movable in the directions indicated by arrow 32 by the piston 29, and an electromagnetic valve 35 for introducing compressed air to the cylinder 27 beneath the under surface of the piston 29 and exhausting the air when necessary.
  • a roller 36 On the end of the movable rod member 33 there is disposed a roller 36.
  • a return spring 37 is connected between the-shaft 13 and cylinder 27 for urging the separation of contact members 1 and 8.
  • Numeral 38 denotes means for extinguishing arcs.
  • Numeral 40 generally represents a supplementary contact mechanism used in the device for selectively indicating normal cutoffs and those of excess current.
  • This supplementary contact mechanism 40 comprises a displacement member 39 displaceable in the directions of the arrow 32 according to the movement of the shaft of the movable member 33 to which it is connected, a cam 41 mounted thereon having a stepped cam surface consisting of low and high planes 41a and 411), respectively, and a roller 43 for causing a movable contact member 42a of a contact device 42 forming one component part of the supplementary contact mechanism 40 on which it is disposed to be detachably pressed against a fixed contact member 42b of the contact device 42.
  • Numeral 44 shows an insulation material.
  • FIGS. 1 through 4 the operation of the circuit breaker of the present invention will be described.
  • the roller 36 when compressed air is supplied to the underside of the piston 29 by exciting the electromagnetic valve 35, the roller 36 is moved upward to push against a driving surface 46 of the first movable arm 5.
  • General counterclockwise rotation of the arm about shaft 13 on the arm 12 under the force of roller 36 against the surface 46 is resisted by the sliding engagement of roller-18 over cam surface 14a. Consequently, both arms 5 and 12 are jointly rotated upward, thereby causing the contact members 1 and 8 to be attached to each other as indicated.
  • the movable member 33 is moved up through a distance I and consequently the cam 41 affixed thereto is lifted similarly through the same distance I. Since, under this condition, the roller 43 contacts the lower plane 41a of the cam 41, the contact members 42a and 42b remain separated. Therefore, unless the compressed air is evacuated from the cylinder 27, the circuit breaker is kept in operation.
  • Normal cutoffs are effected in the following manner.
  • the piston 29 is urged downwardly by the action of the spring 28, thereby causing the roller 36 to rapidly move out of contact with the driving surface 46 on arm 5 and the first and second movable arms 5 and 12 to rotate in an engaged state so as to cause the contact member 1 and 8 to be separated.
  • the final condition of said normal cutoff is the same as that before the circuit breaker is put into operation, as illustrated in FIG. 1.
  • the roller 43 contacts the lower plane 41a of the cam 41, so that the contact members 4211 and 42b are detached from each other.
  • the movable iron core 20 is attracted, as shown in FIG. 3, to the fixed iron core 19, causing the projecting arm 23b of the movable arm 23 to rotate counterclockwise whereby the roller 25 engages the head of the projection 16a of the arm 16, to pivot thereby disengaging the roller 18 from the cam surface 14a of the cam 14. Accordingly, the movable member 33 is urged further upward through an additional distance of I to lift the driving point 46. Since, at this time, the return spring 37 continues to urge the rotary shaft 13 downward, the arm 5 is rotated about the shaft 13 in a counterclockwise direction, whereby the movable contact member 8 on one end of the arm 5 instantly rotates counterclockwise therewith to effect a rapid cutoff of the excess current.
  • FIG. 4 represents modifications of the supplementary indicating contact mechanism associated with the operation of the circuit breaker of this invention and the cutoff performed thereby.
  • the cam 41, and the low and high planes 41a and 41b thereof are denoted by the same numerals, regardless of their forms.
  • the cam 41 is free to move in the directions of the arrow 32 and the roller 43 to shift in the directions of the arrow 47.
  • FIG. 4C under the cutoff condition of FIG. 1, the cam 41 assumes the solid line position and the roller 43 is located at the lower cam plane 41a, leaving the contact members 42a and 42b separated. Under the operating condition of FIG. 2, the cam 41 advances through the distance I, but the roller remains on the surface 41a. Therefore the contact members remain open.
  • the cam 41 is further urged through an additional distance I and the roller 43 runs on the higher cam plane 41b to cause the contact members 42a and 42b to contact each other.
  • the movable member 33 is brought downward,
  • the cam 41 may be so changed in form, as illustrated in FIG. 4D, as to cause the contact members 42a and 42b to contact each other during the operation of the circuit breaker and during normal cutoffs and to be separated only during cutoffs made because of excess current. It is also possible, as shown in FIG. 4A, to cause the contact members 42a and 42b to be separated during normal cutoffs and to contact each other both during the periods of operation of the circuit breaker and cutoffs due to excess current. It is further possible, as illustrated in FIG. 4B, to cause the contact members 42a and 42b to contact each other during normal cutoffs and to be detached from each other during the operation of the circuit breaker and at cutofi's effected by excess current.
  • a circuit breaker comprising: a fixed contact member connected to one end terminal of said circuit breaker;
  • a contact member on said first movable arm for detachably contacting the fixed contact member so as to switch a circuit across both terminals of said circuit breaker
  • said means on said second movable arm for rotatably supporting said first movable arm is a shaft secured to the other end thereof which supports said first movable arm at an intermediate point thereon.
  • said movable arm advancing means is a member reciprocably movable in a given path engageable upon movement in one direction with a point on said first movable arm positioned between the rotating center thereof and the point of engagement of said first and second movable arms.
  • first and second movable arm engaging means comprises a cam disposed on the end of said first movable arm opposite said contact and a cam follower secured to said second movable arm adjacent said one end thereof.
  • circuit breaker of claim 1 further including means for selectively indicating normal cutoffs and those of excess current from the condition in which the contact members contact each other.
  • a circuit breaker according to claim 9 wherein the selective indication means comprises a cam fixed to said movable arm advancing means and supplementary contact members attachable and detachable from each other accordingto the displacement of said cam.
  • circuit breaker of claim 4 further including means for selectively indicating normal cutoffs and those of excess current from the condition in which the contact members contact each other comprising:
  • a cam fixed to said movable member of said movable arm advancing means; and supplementary contact members having a cam follower associated therewith for engaging and disengaging said supplementary contact members according to the displacement of said cam.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Breakers (AREA)
  • Mechanisms For Operating Contacts (AREA)
  • Switch Cases, Indication, And Locking (AREA)
US113854A 1970-02-09 1971-02-09 Circuit breaker Expired - Lifetime US3639865A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP45010901A JPS4946180B1 (enrdf_load_stackoverflow) 1970-02-09 1970-02-09

Publications (1)

Publication Number Publication Date
US3639865A true US3639865A (en) 1972-02-01

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ID=11763190

Family Applications (1)

Application Number Title Priority Date Filing Date
US113854A Expired - Lifetime US3639865A (en) 1970-02-09 1971-02-09 Circuit breaker

Country Status (4)

Country Link
US (1) US3639865A (enrdf_load_stackoverflow)
JP (1) JPS4946180B1 (enrdf_load_stackoverflow)
DE (1) DE2106084A1 (enrdf_load_stackoverflow)
GB (1) GB1290294A (enrdf_load_stackoverflow)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103794402A (zh) * 2012-10-30 2014-05-14 Ls产电株式会社 真空断路器的机械操作室开关

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6378752U (enrdf_load_stackoverflow) * 1986-11-13 1988-05-25

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3366900A (en) * 1966-06-16 1968-01-30 Gen Electric Electric circuit breaker with electromagnetic means for opposing contactrepulsion forces
US3590192A (en) * 1968-10-24 1971-06-29 Westinghouse Electric Corp Supporting and spring-charging means for circuit breaker

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3366900A (en) * 1966-06-16 1968-01-30 Gen Electric Electric circuit breaker with electromagnetic means for opposing contactrepulsion forces
US3590192A (en) * 1968-10-24 1971-06-29 Westinghouse Electric Corp Supporting and spring-charging means for circuit breaker

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103794402A (zh) * 2012-10-30 2014-05-14 Ls产电株式会社 真空断路器的机械操作室开关
US9136076B2 (en) 2012-10-30 2015-09-15 Lsis Co., Ltd. Mechanically operated cell switch of vacuum circuit breaker
CN103794402B (zh) * 2012-10-30 2016-01-20 Ls产电株式会社 真空断路器的机械操作室开关

Also Published As

Publication number Publication date
JPS4946180B1 (enrdf_load_stackoverflow) 1974-12-09
GB1290294A (enrdf_load_stackoverflow) 1972-09-27
DE2106084A1 (de) 1971-08-19

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