US3747033A - Circuit breaker with improved trip means - Google Patents

Circuit breaker with improved trip means Download PDF

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Publication number
US3747033A
US3747033A US00220667A US3747033DA US3747033A US 3747033 A US3747033 A US 3747033A US 00220667 A US00220667 A US 00220667A US 3747033D A US3747033D A US 3747033DA US 3747033 A US3747033 A US 3747033A
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US
United States
Prior art keywords
contact arm
latch
primary latch
operating
move
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
US00220667A
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English (en)
Inventor
R Bennett
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.)
ABB Inc USA
Original Assignee
Westinghouse Electric Corp
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 Westinghouse Electric Corp filed Critical Westinghouse Electric Corp
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Publication of US3747033A publication Critical patent/US3747033A/en
Assigned to ABB POWER T&D COMPANY, INC., A DE CORP. reassignment ABB POWER T&D COMPANY, INC., A DE CORP. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: WESTINGHOUSE ELECTRIC CORPORATION, A CORP. OF PA.
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • 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
    • H01H71/40—Combined electrothermal and electromagnetic mechanisms

Definitions

  • ABSTRACT A circuit breaker is provided with improved compactly constructed trip means comprising a thermal trip operable with time delay in response to a sustained overload above a first predetermined value to effect automatic opening of the breaker and an electromagnetic trip operable instantaneously upon the occurrence of an overload above a second predetermined value to effect automatic opening of the breaker.
  • An improved compactly constructed circuit breaker comprises an elongated movable contact arm that is pivotally connected intermediate the ends thereof to an operating link of 'a spring-type operating mechanism.
  • the elongated movable contact arm is provided with a contact at one end thereof for cooperating with a stationary contact.
  • the contact arm is latched at the other end thereof by means of an elongated primary latch that is pivotally supported intermediate the ends thereof.
  • the spring-type operating mechanism is manually operable between open and closed positions to pivot the contact arm about the latched end between open and closed positions with a snap-action.
  • Trip means is provided comprising a thermal trip and an electromagnetic trip.
  • the thermal trip comprises a secondary; latch member that is latched by abimetalact-ivated latch and that is spring-biased toward a tripping position.
  • the electromagnetic trip comprises a flapper type armature that is pivotally supported for movement about the same axis as the primary latch.
  • FIG. 1 is a side sectional view of a circuit breaker embodying principles of this invention with the breaker being shown in the manually closed position in full lines and with the manually open position of the breaker being indicated in broken lines;
  • FIG. 2 is a view similar to FIG. 1 with the breaker being shown in the tripped-open position following an electromagnetic tripping operation;
  • FIG. 3 is a partial sectional view taken generally along the lines III-III of FIG. 2;
  • FIG. 4 is a perspective view of the armature structure seen in FIGS. 1-3.
  • the movable contact is fixedly mounted on one end I of an elongated contact arm structure 25 that is latched, at the other end 27 thereof, in the operating position seen in FIG. 1 by means of an elongated primary latch member 29.
  • the primary latch member 29 is mounted for pivotal movement, intermediate the ends thereof, on a fixed pivot 30.
  • the contact arm structure 25 comprises an elongated arm portion 31 and a U-shaped member 33 that carries the contact 15 and that is mounted on the portion 31, by means of a pivot pin 35, for limited movement relative to the arm portion 31 to provide contact alignment in the closedcontact position.
  • the movable contact 15 is fixedly mounted on the U-shaped member 33.
  • the contact arm structure 25 is supported at 27 on a latch surface 37 of the primary latch 29, and the contact arm 25 pivots on the latch surface 37, during manual operation of the circuit breaker in a manner to be hereinafter described.
  • a tension spring 39 is connected at one end thereof to an extension 41 of the contact arm structure 25, and at the other end thereof to a stationary spring support pin 43.
  • the contact arm structure 25 is pivotally connected, intermediate the ends thereof, to an operating link 45 by means of a pivot pin 47.
  • a pair of operating springs 49 (only one of which is seen in FIG. 1) are connected at one end to a pin 51 on the upper end of the operating link 45 and at the other end to an insulating operating handle 53.
  • the operating link 45 comprises twin members connected by means of the pin 51.
  • a roller 55 is mounted on the pin 47 between the twin members of the link 45 and a roller 57 is mounted on the pin 51 between the twin members of the link 45.
  • the rollers 55, 57 are positioned in a generally triangular shaped opening 59 in the insulating base 11, and they engage the surfaces defining the opening 59 to guide movement of the operating link 45in a manner to be hereinafter described.
  • the insulating handle 53 which is biased inward by means of the tension springs 49, rides on an arcuate surface 61 which guides the handle 53 for movement between the on" and on positions.
  • the breaker is closed by reverse movement of the handle 53 from the off position to the on position. During this movement, the line of action of the operating springs 49 crosses over the center line B-57 where-' upon the springs 49 bias the roller 57 to move the operating link 45 and movable contact arm structure to the closed position. with a snap-action- Referring to FIG.
  • the circuit in the closed position of the circuit breaker, the circuit extends from a conductor 65 through a conductor 21, the stationary contact 13, the movable contact 15, the member 33, flexible conductors 67 that are connected at one end to the member 33 and at the other end to a conductor 69, the conductor 69, a bimetal 71 that is connected at one end to the conductor 69 and at the other end to a conductor 73, the conductor 73 to a flexible conductor 75 that is connected to the conductor 73.
  • the bimetal 71 is fixedly secured at the upper side thereof to an adjusting arm A that is suitably pivotally secured to the housing 11 in the manner more specifically described in the above-mentioned U.S. Pat. No.
  • a latch member 77 which is fixedly secured at one end thereof to the free end of the bimetal 71, latches a secondary latch member 79 that is pivotally mounted on a stationary pivot 81 and that is biased in a clockwise (FIG. 1) direction by means of a tension spring 83.
  • the bimetal 71 becomes heated and flexes, with a time delay, upward (FIG. 1) whereupon the latch 77 releases the secondary latch member 79.
  • the spring 83 snaps the secondary latch member 79 clockwise about the pivot 81 causing a projection 85 on the secondary latch member 79 to engage the one end 87 of the primary latch member 29 to pivot the primary latch member 29 in a counterclockwise direction about the fixed pivot 30, against the bias of a torsion spring 89.
  • This movement moves the latch surface 37 to release the latched end 27 of the contact arm 25 whereupon the tension spring 39 moves the contact arm 25 about the pivot 47 to a tripped-open position with a snap-action.
  • the mechanism is reset and relatched following an automatic opening operation by moving the handle 53 to a position slightly past the off" position.
  • the latching end 27 of the contact arm 25 is moved up over the latch surface 37 of the primary latch member 29, and as the handle 53 approaches the off position, a projection 93 thereon engages the secondary latch member 79 to rotate the secondary latch member 79 counterclockwise about the pivot 81 where the latch member 79 is again relatched by the latch 77.
  • the trip means 19 comprises an electromagnetic trip that comprises an armature structure indicated generally at 101.
  • the armature structure 101 (FIG. 4) comprises a support arm 103 having a support bearing 105 secured thereto.
  • the support bearing 105 has an opening therein for receiving the fixed pivot pin 30 (FIG. 1) to pivotally support the armature structure 101 on the fixed pivot pin 30 for pivotal movement about the same axis as the primary latch 29.
  • a laminated magnetic armature 107 is secured to the support arm 103 by means of a pair of rivets 109.
  • An insulating fiber wrapper 113 is suitably secured to the armature 107.
  • a striker arm 115 is secured to the armature 107 on the underside of the armature 107.
  • the striker member 115 of the armature structure 101 is disposed under the primary latch 29 to engage the primary latch 29 upon attraction of the armature structure, which engagement is on the same side of the pivot 30 of the primary latch 29 as the support surface 37 that the contact arm 25 is pivoted on.
  • the armature structure 101 is positioned in an unattracted position spaced from the bimetal 71 and conductor 69 with the armature structure 101 being maintained in the unattracted position by means of the pull of gravity.
  • a biasing spring could be utilized to bias the armature structure 101 to the unattracted position for certain applications. Pivotal movement of the armature structure 101 to the unattracted position seen in FIG. 1 is limited by engagement of the armature structure 101 with a surface 116 of the insulating housing 11.
  • the armature structure 101 is in the attracted position to show the position at the moment of tripping. It can be understood that when the circuit is open the armature structure 101 will be returned by gravity (or a biasing spring if a biasing spring is used) to the unattracted position seen in FIG. 1. As can be understood with reference to FIG. 2, re lease of the secondary latch 79 is not necessary for an electromagnetic tripping operation in that the primary latch 29 is engaged by the striker arm 115 to directly move the primary latch 29 to the releasing or tripped position. Following an electromagnetic tripping operation, the contact arm 25 is reset by movement of the handle 53 to the off position during which movement the operating link 45 is moved to the position shown in broken lines in FIG.
  • the circuit breaker can be manually operated in the same manner as was hereinbefore described.
  • a circuit breaker comprising a stationary contact, a movable contact, an elongated contact arm carrying said movable contact at one end thereof, a primary latch supported for movement about a first axis and being in a latching position latching the other end of said contact arm, a secondary latch in a latched position, biasing means biasing said secondary latch toward a tripping position, a bimetal-actuated latch latching said secondary latch in said latched position, a spring operating mechanism pivotally connected 'tosaid contact arm intermediate the ends of said contact arm, said spring operating mechanism beingmanually operable to pivot said contact arm about said other end on said primary latch between open and closed positions with a snap action, upon the occurrence of lesser overloads above a first predetermined value said bimetalact'uated latch releasing said secondary latch whereupon said biasing means moves said secondary latch to effect movement of said primary latch to unlatch said contact arm whereupon said spring operating mechanism moves said contact arm to a tripped-open position, an armature structure
  • a circuit breaker according to claim I and said spring operating mechanism being operable when said contact arm is in said tripped-open position to move said contact arm to relatch said contact arm to prepare said circuit breaker for manual operation.
  • a circuit breaker according to claim 1 upon the occurrence of lesseroverloads above said first predetermined value said bimetal-actuated latch releasing said secondary latch whereupon said biasing means moves said secondary latch to strike said primary latch on a first side of said first axis to thereby move said primary latch to unlatch said contact arm whereupon said spring operating mechanism moves said contact arm to a tripped-open position, and upon the occurrence of overloads above said second predetermined value said armature structure pivotally moving to strike said primary latch on said first side of said first axis to move said primary latch to unlatch said contact arm whereupon said spring operating mechanism moves said contact arm to said tripped-open position.
  • a circuit breaker comprising a stationary contact, a movable contact, an elongated contact arm carrying said movable contact at one end thereof, a primary latch supported on a fixed pivot and comprising a latch part on a first side of said fixed pivot engaging the other end of said contact arm to latch the other end of said contact arm, an operating mechanism comprising an operating link, means pivotally connecting said contact arm intermediate the ends thereof to said operating link, an operating member, an operating spring connected between said operating member and said operating link, said operating member being manually operable to an open position to operate through said operating spring and operating link to move said latched contact arm about said other end to a manually open position, said operating member being manually operable to a closed position to operate through said operating spring and operating link to move said latched contact arm about said other end to a manually closed position, trip means'comprising a thermal trip operating with a time delay upon the occurrence of a sustained overload above a first predetermined value to move said primary latch to an unlatching position to unlatch said other end of
  • a circuit breaker according to claim 4 said primary latch being supported on said fixed pivot for pivotal movement about a first axis, and said movable armature being pivotally supported for movement about said first axis.
  • a circuit breaker according to claim 4 a secondary latch, said thermal trip comprising a bimetal in an initial position to effect latching of said secondary latch, upon the occurrence of said overload above said first predetermined value said bimetal flexing to unlatch said secondary latch and said secondary latch moving to operate against said primary latch on said first side of said fixed pivot of said primary latch to move said primary latch to the unlatching position, said otal movement about said fixed pivot pin.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Breakers (AREA)
US00220667A 1972-01-25 1972-01-25 Circuit breaker with improved trip means Expired - Lifetime US3747033A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US22066772A 1972-01-25 1972-01-25

Publications (1)

Publication Number Publication Date
US3747033A true US3747033A (en) 1973-07-17

Family

ID=22824463

Family Applications (1)

Application Number Title Priority Date Filing Date
US00220667A Expired - Lifetime US3747033A (en) 1972-01-25 1972-01-25 Circuit breaker with improved trip means

Country Status (6)

Country Link
US (1) US3747033A (en:Method)
JP (1) JPS5344684Y2 (en:Method)
AT (1) AT320058B (en:Method)
CA (1) CA959893A (en:Method)
CH (1) CH544406A (en:Method)
DE (1) DE2302039A1 (en:Method)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4716325A (en) * 1986-11-06 1987-12-29 Autotrol Corporation Disengageable one-way mechanism for synchronous motors
US4789949A (en) * 1986-10-14 1988-12-06 International Business Machines Corporation Printer throughput
US5844188A (en) * 1996-12-19 1998-12-01 Siemens Energy & Automation, Inc. Circuit breaker with improved trip mechanism
US5866996A (en) * 1996-12-19 1999-02-02 Siemens Energy & Automation, Inc. Contact arm with internal in-line spring
US5894260A (en) * 1996-12-19 1999-04-13 Siemens Energy & Automation, Inc. Thermal sensing bi-metal trip actuator for a circuit breaker
US6087914A (en) * 1996-12-19 2000-07-11 Siemens Energy & Automation, Inc. Circuit breaker combination thermal and magnetic trip actuator

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3451016A (en) * 1966-11-10 1969-06-17 Ellenberger & Poensgen Pushbutton-actuated overload circuit breaker
US3525058A (en) * 1968-04-30 1970-08-18 Westinghouse Electric Corp Circuit breaker with improved trip means

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3451016A (en) * 1966-11-10 1969-06-17 Ellenberger & Poensgen Pushbutton-actuated overload circuit breaker
US3525058A (en) * 1968-04-30 1970-08-18 Westinghouse Electric Corp Circuit breaker with improved trip means

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4789949A (en) * 1986-10-14 1988-12-06 International Business Machines Corporation Printer throughput
US4716325A (en) * 1986-11-06 1987-12-29 Autotrol Corporation Disengageable one-way mechanism for synchronous motors
US5844188A (en) * 1996-12-19 1998-12-01 Siemens Energy & Automation, Inc. Circuit breaker with improved trip mechanism
US5866996A (en) * 1996-12-19 1999-02-02 Siemens Energy & Automation, Inc. Contact arm with internal in-line spring
US5894260A (en) * 1996-12-19 1999-04-13 Siemens Energy & Automation, Inc. Thermal sensing bi-metal trip actuator for a circuit breaker
US6087914A (en) * 1996-12-19 2000-07-11 Siemens Energy & Automation, Inc. Circuit breaker combination thermal and magnetic trip actuator

Also Published As

Publication number Publication date
CH544406A (de) 1973-11-15
DE2302039A1 (de) 1973-08-09
AT320058B (de) 1975-01-27
JPS5344684Y2 (en:Method) 1978-10-26
JPS4897647U (en:Method) 1973-11-19
CA959893A (en) 1974-12-24

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AS Assignment

Owner name: ABB POWER T&D COMPANY, INC., A DE CORP., PENNSYLV

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:WESTINGHOUSE ELECTRIC CORPORATION, A CORP. OF PA.;REEL/FRAME:005368/0692

Effective date: 19891229