US3171922A - Circuit breaker with releasable cam type mechanism - Google Patents

Circuit breaker with releasable cam type mechanism Download PDF

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Publication number
US3171922A
US3171922A US241304A US24130462A US3171922A US 3171922 A US3171922 A US 3171922A US 241304 A US241304 A US 241304A US 24130462 A US24130462 A US 24130462A US 3171922 A US3171922 A US 3171922A
Authority
US
United States
Prior art keywords
cam
cam follower
open
closed circuit
contacts
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
US241304A
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English (en)
Inventor
Kenneth J Stokes
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.)
General Electric Co
Original Assignee
General Electric Co
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
Priority to NL301190D priority Critical patent/NL301190A/xx
Application filed by General Electric Co filed Critical General Electric Co
Priority to US241304A priority patent/US3171922A/en
Priority to GB43607/63A priority patent/GB1002965A/en
Priority to LU44823D priority patent/LU44823A1/xx
Priority to ES0293799A priority patent/ES293799A1/es
Priority to DE19631463253 priority patent/DE1463253A1/de
Priority to FR955130A priority patent/FR1375560A/fr
Priority to BE640606A priority patent/BE640606A/xx
Priority to FR959110A priority patent/FR85047E/fr
Application granted granted Critical
Publication of US3171922A publication Critical patent/US3171922A/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
    • H01H71/00—Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
    • H01H71/10—Operating or release mechanisms
    • H01H71/50—Manual reset mechanisms which may be also used for manual release
    • H01H71/52—Manual reset mechanisms which may be also used for manual release actuated by lever
    • 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
    • H01H71/50—Manual reset mechanisms which may be also used for manual release
    • H01H71/52—Manual reset mechanisms which may be also used for manual release actuated by lever
    • H01H71/522—Manual reset mechanisms which may be also used for manual release actuated by lever comprising a cradle-mechanism

Definitions

  • a particular type of operating mechanism has been widely used for manually and automatically operating movable contacts between open and closed circuit positions in electric circuit breakers of medium and high capacity, such for example as 100 to 1200 amperes.
  • This type of mechanism incorporates a pivotally supported contact arm and means for operating the contact arm between open and closed circuit positions, comprising a pair of toggle links interconnected between the movable contact arm and a releasable support member.
  • the releasable support member is normally held in a position such that when the toggle links are in straightened condition, the movable contact arm is held in closed circuit position and when the toggle links are in collapsed condition, the contact arm is in an open circuit position.
  • the action of the over-center spring is such as to cause opening movement of the contact arm even through the operating handle is manually held in the closed or on position.
  • Speed of contact opening likewise, depends partly on the nature of the operating springs which can be provided, and also on the rate of possible movement of the component parts of the mechanism. Thus, for example, a finite amount of time is required for each part of such a mechanism to move, and therefore, a limit is reached as to possible speed of movement, regardless of strength of operating springs.
  • an electric circuit breaker is provided of the type including a pivotally supported movable contact arm having an operating link pivotally connected thereto.
  • a releasable support member is also provided, which is normally latched and which is releasable upon the occurrence of predetermined current conditions.
  • the releasable member is provided with an arcuate cam surface, and the link connected to the movable contact arm is provided with a cam follower, preferably in the form of a roller disposed and arranged to travel along the aforesaid cam surface.
  • One or more tension springs are also provided connected between the cam follower or roller and the movable portion of a manually operable member.
  • the manually operable member is carried on a handle support which is pivotally supported on a fixed pivot in the enclosing casing.
  • FIGURE 1 is a side elevation view of an electric circuit breaker incorporating the invention, the side wall being broken away, and the parts being shown in the normal open circuit positions;
  • FIGURE 2 is a side elevation view of the operating mechanism portion of the circuit breaker of FIGURE 1, the parts being shown in the normal closed or on position;
  • FIGURE 3 is a view similar to FIGURE 2, the parts being shown in the automatically opened or tripped condition;
  • FEGURE 4 is a fragmentary sectional view taken substantially on the line 44 of FIGURE 2;
  • FIGURE 5 is an exploded perspective view of a portion of the operating mechanism of FIGURE 1, and
  • FIGURE 6 is a side elevation view of another embodiment of the invention.
  • an electric circuit breaker comprising an insulating casing including a base 19 and a cover 11.
  • the casing is generally rectangular and includes three line terminals, not shown, at one end, and three load terminals, not shown, at the other end. Electrical continuity between each pair of corresponding line and load terminals is controlled by a pair of contacts including a relatively movable contact 12 and a relatively stationary contact 13, only one pair shown.
  • the current path provided between each pair of line and load terminals is referred to conventionally as a pole, and the circuit breaker illustrated is therefore ia three-pole circuit breaker.
  • Each of the movable contacts 12 is carried by a movable contact support 14, which is pivotally connected to a generally channel-shaped contact arm 15 by a pivot pin 16.
  • the forward end of the contact support 14 has a post 14A extending through an opening in the contact arm 15.
  • a compression spring 14A is positioned on the post 14A between the support 14 and the contact arm 15.
  • the contact support 14 has a flexible conductor 14C connected thereto adjacent the pivot pin 16 by suitable means, such as by brazing.
  • the contact arm 15 for the central pole space is illustrated in FIGURE 1, and is pivotally supported on pivot pin 17 which in turn is supported between two spaced-apart side plate portions 18 of a stationary frame assembly.
  • the contact arm 15 3 is generally channel-shaped throughout its major portion, and the pins 16 and 17 pass through depending side portions of the channel-shaped portion.
  • the contact arm for each pair of line and load terminals is anchored by suitable fastening means to a contact cross-arm 21. Movement of the center contact arm 15 about its pivot point 17 in the frame 18 therefore carries with it the two outside contact arms, not shown.
  • operating mechanism is provided at the center pole, including a pair of operating links 24 which extend through slots 15A in the contact arm 15 and are pivotally connected to the contact arm 15 by means of pivot pin 16.
  • the pin 16 is trapped in position by the side plates 18 as illustrated in FIGURE 4.
  • the links 24 are interconnected by a pin 25 which carries a generally spool-shaped roller 26 generally centrally thereof.
  • the links 24 are retained on the pin 25 by suitable means such as by snap-rings 27 engaging in grooves 28 of the pin 25.
  • a releasable cam member 30 is also provided which is rigidly attached or may be made integral with a supporting shaft 31 which is pivotally supported in bearings or holes in the upper portion of the slide plates 18.
  • the releasable cam member 30 also includes a latch portion 32 at the end thereof opposite the shaft 31.
  • the latch 32 is normally engaged and releasably held by a latching or restraining member 33, which is controlled by suitable current-responsive means, to be described.
  • the releasable cam member 30 also includes an elongated convex arcuate cam surface 34, on which the roller 26 is adapted to ride.
  • the roller 26 also includes a pair of flange portions 26A disposed and arranged to maintain the roller 26 in proper relation to the cam surface 34 of the releasable member 30.
  • the latch member 33 is supported on a pin 45 pivotally journalled in a bracket 46 which is rigidly attached to the insulating casing 47 of a trip unit 48.
  • the bracket 46 also carries a pivot pin 49 which supports an intermediate latch member 50.
  • the latch member 50 carries a latch roller 51 at an intermediate point, and a latch surface 52 at an end point thereof.
  • the latch surface 52 is releasably engaged and held by a latch member 53 carried by a trip bar 54 pivotally supported at 55 in the trip unit casing.
  • the trip bar 54 is biased counterclockwise as viewed against a suitable stop means, not shown, by compression spring 56, and carries a calibrating screw 57.
  • the latch member 33 is biased counterclockwise, as viewed, by a torsion type spring 58, which also serves to bias the intermediate latch member counterclockwise as viewed.
  • a bimetallic strip 60 is provided for the purpose of rotating the trip bar 54 so as to cause release as described.
  • the bimetallic strip 60 is rigidly supported on a conducting strap 61 which extends between the terminal 62 and the flexible conductor 14C, being connected to the conductor 14C by means of the bolt 63.
  • the conductor 61 has a constricted cross-section at the point where the bimetallic strip 613 is mounted thereon. The passage of current therethrough therefore causes heating of the conductor 61, and such heat is transmitted to the bimetallic strip 6t) by conduction, causing the bimetallic strip to warp so as to move the free end thereof to the right as viewed to engage the calibrating screw 57 and rotate the trip bar 54 as previously described.
  • a generally U-shaped handle support member 35 is provided, which is pivotally supported at its end portions on support pins 36 carried by the side plates 18 respectively (see FIG. 4).
  • the bight portion of the handle support member 35 includes a downwardly bent portion 37 which is adapted to engage a portion 38 of the releasable cam member 30, during resetting of the mechanism, in a manner to be described.
  • a manually engageable handle member 39 is also provided mounted on the handle support member 35 and including a manually engageable part extending outwardly through an opening 46 in the casing cover 11, and an enlarged skirt portion having closely fitting engagement with the bight portion of the U-shaped handle support 35. Suitable fastening means, such as screws, not shown, are also preferably utilized to attach the insulating handle member 39 to the handle support member 35.
  • a pair of tension type operating springs 40 are also provided, one on each side of the releasable cam member 30.
  • the springs 40 are connected at one end, by means of retaining pins 41, to the handle support member 35, and are connected at the other end to the pin 25, on opposite sides of the cam follower roller 26, respectively.
  • the operating springs 40 bias the cam follower roller 26 in the general direction of the center of the curvature of the cam surface 34.
  • the cam surface 34 is designed so that in the off position of the operating handle as shown in FIGURE 1, the tension springs 40 act on the roller 26, in such a way as to have a resultant force which urges the cam follower roller 26 to the right as viewed in FIGURE 1, thereby retaining the contact arm 15 and the associated contact arms of the other poles carried by the contact cross-arm 21, in the off or open-circuit position.
  • the manually engageable handle member is moved from the off position as shown in FIGURE 1 to the on position as shown in FIGURE 2.
  • the handle member 39 is moved toward the left, or toward the on position, there is no motion of the roller 26 along the cam surface 34 until the angle of the springs 40 with respect to the cam surface 34 is such as to cause such movement.
  • the handle 39 has travelled part way toward the full on position.
  • the roller 26 moves along the cam surface 34 quickly with a snap-action, and the parts then move to the condition shown in FIGURE 2.
  • the links 24 are in locked relation withrespect to the arm 15, being in engagement with the portion 15B forming one end of the aperture 15A through which the links 24 extend respectively.
  • the stop for automatic opening motion of the system comprises the engagement of the contact arm 15 with the shaft 31 or with the portion of the releasable member 32, closely adjacent the shaft 31. In the position shown in FIGURE 3, therefore, there is no appreciable force exerted on the releasable member 30, :and it is essentially free-floating between the roller 26 and the handle support member 35.
  • the handle support member 35 is held in the on position, as shown in dotted lines in FIGURE 3, the releasable cam member 30 will remain in the position shown due to the action of gravity thereon. If the handle member 39 is not held in the on position when tripping occurs, the handle will be moved to an intermediate or trip indicating position as indicated in FIGURE 3. This action occurs because the roller 26 carries thepin 25 to the right as viewed, so that the line of action of the springs lies to the right of the pivotal support 36 of the handle support member 35. The pull of the springs 40, thereafter, on the handle support member 35, is therefore such as to tend to cause clockwise rotation of the handle support member 35. The handle support member 35 therefore moves to the right as viewed in FIGURE 3 until the depending portion 37 engages the portion 38 of the cam member 30. The handle therefore remains in an intermediate or trip indicating position following automatic opening.
  • the handle 39 In order to reset and reclose the circuit :breaker, the handle 39 is moved to the full off position, that is, to the extreme clockwise position, as shown in FIGURE 1. This causes the handle support member .35 to move the releasable member 30 clockwise by reason of the engagement of part 37 of the handle support 35 with portion 38 of the member 30, until the latch portion 32 is once again engaged under and held by the retaining member 33. The handle may thereafter be moved back toward on position, to reclose the circuit breaker in the manner previously described.
  • FIGURE 6 there is shown another embodiment of the invention, in which a releasable member is provided which includes a stop projection integral with the releasable cam member 130.
  • the other par-ts of the mechanism are otherwise similar to the form previously described.
  • the projection 145 acts as a stop for the travel of the Links 24 in the contact closing direction.
  • the releasable member 130 is an accurately-made piece, manufactured by either stamping or by forging and machining, the exact location of the stop 145 is readily assured by this construction and can be more accurately controlled than when a portion of the contact arm 15 is used as such a stop as shown in the previous form. Operation of this form of the invention is otherwise similar to that previously described.
  • An electric circuit breaker comprising:
  • a releasable cam member pivotally supported in said insulating casing and including a convex cam surface and a latch portion
  • operating spring means comprises at least one tension type spring having one end thereof connected to said point of said manually operable member and having the other end thereof connected to said point of said cam follower member.
  • An electric circuit breaker comprising:
  • a manually operable handle member pivotally supported in said insulating casing for movement about an axis extending perpendicular to said side walls and including a portion projecting through said top wall, said handle being movable between on and off positions,
  • (11) at least one tension type operating spring connecting said manually operable member to said cam follower member, said tension spring urging said handle member toward said back wall and urging said cam follower member upwardly toward said top wall into engagement with said cam surface, whereby to urge said cam member for rotation about its pivotal support upwardly toward said top surface,
  • An electric circuit breaker comprising:
  • a releasable cam member pivotally supported in said insulating enclosure and including a convex cam surface and a latch portion

Landscapes

  • Breakers (AREA)
  • Driving Mechanisms And Operating Circuits Of Arc-Extinguishing High-Tension Switches (AREA)
US241304A 1962-11-30 1962-11-30 Circuit breaker with releasable cam type mechanism Expired - Lifetime US3171922A (en)

Priority Applications (9)

Application Number Priority Date Filing Date Title
NL301190D NL301190A (de) 1962-11-30
US241304A US3171922A (en) 1962-11-30 1962-11-30 Circuit breaker with releasable cam type mechanism
GB43607/63A GB1002965A (en) 1962-11-30 1963-11-05 Improvements in electric circuit breakers
LU44823D LU44823A1 (de) 1962-11-30 1963-11-15
ES0293799A ES293799A1 (es) 1962-11-30 1963-11-23 Interruptor de circuito electrico
DE19631463253 DE1463253A1 (de) 1962-11-30 1963-11-27 Elektrischer Trennschalter
FR955130A FR1375560A (fr) 1962-11-30 1963-11-27 Interrupteur électrique perfectionné
BE640606A BE640606A (de) 1962-11-30 1963-11-29
FR959110A FR85047E (fr) 1962-11-30 1963-12-31 Interrupteur électrique perfectionné

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US241304A US3171922A (en) 1962-11-30 1962-11-30 Circuit breaker with releasable cam type mechanism

Publications (1)

Publication Number Publication Date
US3171922A true US3171922A (en) 1965-03-02

Family

ID=22910135

Family Applications (1)

Application Number Title Priority Date Filing Date
US241304A Expired - Lifetime US3171922A (en) 1962-11-30 1962-11-30 Circuit breaker with releasable cam type mechanism

Country Status (7)

Country Link
US (1) US3171922A (de)
BE (1) BE640606A (de)
DE (1) DE1463253A1 (de)
ES (1) ES293799A1 (de)
GB (1) GB1002965A (de)
LU (1) LU44823A1 (de)
NL (1) NL301190A (de)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3309479A (en) * 1964-06-03 1967-03-14 Gen Electric Electric circuit breaker operating mechanism
US3324264A (en) * 1965-09-24 1967-06-06 Ite Circuit Breaker Ltd Circuit breaker mechanism with improved mounting arrangement for auxiliary features
US3436710A (en) * 1967-05-24 1969-04-01 Gen Electric Electric circuit breaker
US3486150A (en) * 1965-10-24 1969-12-23 Texas Instruments Inc Circuit breaker
EP0233322A2 (de) * 1981-03-12 1987-08-26 Mitsubishi Denki Kabushiki Kaisha Ausschalter
US20100164676A1 (en) * 2008-12-31 2010-07-01 Ls Industrial Systems Co, Ltd. Trip device
US20120161920A1 (en) * 2010-12-28 2012-06-28 Lsis Co., Ltd Bimetal assembly for circuit breaker

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5337031A (en) * 1993-08-20 1994-08-09 General Electric Company Cost-efficient industrial-rated molded case breaker

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2124413A (en) * 1934-03-29 1938-07-19 Bulldog Electric Prod Co Circuit breaker
US2174232A (en) * 1936-08-26 1939-09-26 Westinghouse Electric & Mfg Co Circuit breaker
US2214695A (en) * 1938-03-19 1940-09-10 Westinghouse Electric & Mfg Co Circuit breaker
US2287875A (en) * 1939-10-25 1942-06-30 Westinghouse Electric & Mfg Co Circuit breaker
US2613296A (en) * 1949-06-24 1952-10-07 Morris B Wood Trip-free circuit breaker
US2892127A (en) * 1956-05-07 1959-06-23 Westinghouse Electric Corp Circuit breaker devices
US2921169A (en) * 1957-08-22 1960-01-12 Gen Electric Electric circuit breaker
US2955177A (en) * 1958-07-08 1960-10-04 Wood Electric Co Inc Circuit breaker
US3003046A (en) * 1959-10-26 1961-10-03 Fed Pacific Electric Co Circuit breaker

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2124413A (en) * 1934-03-29 1938-07-19 Bulldog Electric Prod Co Circuit breaker
US2174232A (en) * 1936-08-26 1939-09-26 Westinghouse Electric & Mfg Co Circuit breaker
US2214695A (en) * 1938-03-19 1940-09-10 Westinghouse Electric & Mfg Co Circuit breaker
US2287875A (en) * 1939-10-25 1942-06-30 Westinghouse Electric & Mfg Co Circuit breaker
US2613296A (en) * 1949-06-24 1952-10-07 Morris B Wood Trip-free circuit breaker
US2892127A (en) * 1956-05-07 1959-06-23 Westinghouse Electric Corp Circuit breaker devices
US2921169A (en) * 1957-08-22 1960-01-12 Gen Electric Electric circuit breaker
US2955177A (en) * 1958-07-08 1960-10-04 Wood Electric Co Inc Circuit breaker
US3003046A (en) * 1959-10-26 1961-10-03 Fed Pacific Electric Co Circuit breaker

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3309479A (en) * 1964-06-03 1967-03-14 Gen Electric Electric circuit breaker operating mechanism
US3324264A (en) * 1965-09-24 1967-06-06 Ite Circuit Breaker Ltd Circuit breaker mechanism with improved mounting arrangement for auxiliary features
US3486150A (en) * 1965-10-24 1969-12-23 Texas Instruments Inc Circuit breaker
US3436710A (en) * 1967-05-24 1969-04-01 Gen Electric Electric circuit breaker
EP0233322A2 (de) * 1981-03-12 1987-08-26 Mitsubishi Denki Kabushiki Kaisha Ausschalter
EP0233322A3 (en) * 1981-03-12 1987-09-16 Mitsubishi Denki Kabushiki Kaisha A circuit breaker
US20100164676A1 (en) * 2008-12-31 2010-07-01 Ls Industrial Systems Co, Ltd. Trip device
US8274355B2 (en) * 2008-12-31 2012-09-25 Ls Industrial Systems Co., Ltd. Trip device
US20120161920A1 (en) * 2010-12-28 2012-06-28 Lsis Co., Ltd Bimetal assembly for circuit breaker

Also Published As

Publication number Publication date
GB1002965A (en) 1965-09-02
BE640606A (de) 1964-03-16
ES293799A1 (es) 1964-01-16
LU44823A1 (de) 1964-01-15
DE1463253A1 (de) 1968-12-19
NL301190A (de)

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