US3818168A - Latch mechanism for toggle actuated circuit breaker - Google Patents

Latch mechanism for toggle actuated circuit breaker Download PDF

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Publication number
US3818168A
US3818168A US00311283A US31128372A US3818168A US 3818168 A US3818168 A US 3818168A US 00311283 A US00311283 A US 00311283A US 31128372 A US31128372 A US 31128372A US 3818168 A US3818168 A US 3818168A
Authority
US
United States
Prior art keywords
latch
housing
circuit breaker
latch arm
breaker
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
US00311283A
Other languages
English (en)
Inventor
A Norden
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.)
GEN SWITCH CO
GENERAL SWITCH CO US
Original Assignee
GEN SWITCH 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
Application filed by GEN SWITCH CO filed Critical GEN SWITCH CO
Priority to US00311283A priority Critical patent/US3818168A/en
Priority to CA185,574A priority patent/CA982201A/en
Priority to FR7342867A priority patent/FR2209202B3/fr
Priority to JP48135209A priority patent/JPS4986879A/ja
Priority to IT54017/73A priority patent/IT997837B/it
Priority to GB5584873A priority patent/GB1424929A/en
Application granted granted Critical
Publication of US3818168A publication Critical patent/US3818168A/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
    • H01H71/02—Housings; Casings; Bases; Mountings
    • H01H71/0207—Mounting or assembling the different parts of the circuit breaker
    • H01H71/0214—Housing or casing lateral walls containing guiding grooves or special mounting facilities
    • 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
    • H01H71/523—Manual reset mechanisms which may be also used for manual release actuated by lever comprising a cradle-mechanism the contact arm being pivoted on cradle and mechanism spring acting between handle and contact arm
    • 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
    • H01H71/501—Means for breaking welded contacts; Indicating contact welding or other malfunction of the circuit breaker
    • H01H2071/502—Means for breaking welded contacts; Indicating contact welding or other malfunction of the circuit breaker with direct contact between manual operator and welded contact structure
    • 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
    • H01H71/501—Means for breaking welded contacts; Indicating contact welding or other malfunction of the circuit breaker
    • 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
    • H01H71/505—Latching devices between operating and release mechanism
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S200/00—Electricity: circuit makers and breakers
    • Y10S200/42—Contact welding considerations

Definitions

  • circuit breakers include undue complexity in design and method of assembly, with resultant increase in cost.
  • Another object of the invention is the provision of a circuit breaker as above which may be precisely calibrated.
  • Another object of this invention is the provision of a circuit breaker as above which is substantially resistant to tracking.
  • a further object of this invention is the provision of a circuit breaker as above which is of relatively simple and straight-forward design and method of assembly, and which requires only the use of readily available components of proven dependability in the manufacture thereof, to thus provide for relatively low breaker cost and insure long periods of satisfactory maintenance-free operation thereof.
  • New and improved circuit breaker means comprise a housing of substantially nontracking material having a cavity formed therein.
  • a latch arm is pivotally mounted at one extremity thereof in said housing and extends for latching at the other extremity thereof into a latching notch provided therefor in a latch member.
  • Locating means are provided on said housing and locate said latch arm relative to said latch member at a location on the former relatively closely spaced from said other extremity to thereby reduce the effects of housing instability on the latching function.
  • a contact arm is pivotally mounted on a pivot provided therefor on said latch arm, and a manually operable member is pivotally mounted on said housing and includes a handle which projects from the latter for the manual operation thereof.
  • An over-toggle spring is pivotally mounted from said manually operable member and said contact arm and is operable, upon unlatching of said latch arm in response to an overload or short circuit condition in the breaker-protected line, to pivotally move said contact arm to open the circuit breaker contacts.
  • Manual movement of said manually operable member, with said latch arm in the latch position thereof, is also effective in conjunction with the ef fect of said spring to move said contact arm to open the circuit breaker for servicing of the line or the like.
  • a calibration screw is provided and is readily adjustable from without said housing to calibrate the unlatching of the latch arm, and the mounting means for said calibration screw include vibration-resistant means to inhibit the unwanted loosening of said screw under the effects of a high vibrational stress operational environment of the circuit breaker. Assembly of the circuit breaker is facilitated and rendered relatively inexpensive by the fact that all of the operating components thereof lie substantially flat in the housing cavity whereby no special fixtures of the like are required for such assembly.
  • FIG. 1 is a side elevational view of the circuit breaker with the housing cover plate removed and the circuit breaker in the closed position thereof;
  • FIG. 2 is a side elevational view in the nature of FIG. 1 showing the circuit breaker in the automatically tripped position thereof;
  • FIG. 3 is a side elevational view in the nature of FIGS. 1 and 2 showing the circuit breaker in the manually tripped or open position thereof;
  • FIG. 4 is a cross-sectional view taken along line 44 in FIG. 1;
  • FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. 1.
  • a circuit breaker constructed and operative in accordance with the teachings of this invention is indicated generally at 10 and comprises a housing 12 which is in turn constituted by an appropriately formed housing body 14 and a mating, appropriately formed cover plate 16 which fits tightly thereover and is secured to said housing body by rivets 18 extending therebetween.
  • the housing body 14 and cover plate 16 define an interior chamber 17 therebetween in conventional manner.
  • the housing body 14 and cover plate 16 are preferably made of a suitably electrically insulative and relatively inexpensive material in the nature of urea formaldehyde which, although not exceptionally stable dimensionally, decomposes ablatively and thus offers very substantial, if not total, resistance to tracking (the formation of an electrically conductive path by carbonization in the presence of an arc with resultant unacceptable provision of a current flow path within the circuit breaker housing) to very significant advantage as should be obvious to those skilled in this art.
  • the housing body 14 comprises a pivot pin 20 moulded therein which extends intothe chamber 17.
  • a manually operable member 22 is pivotally mounted on the pin 20 and includes a generally arcuate, breaker op erating portion 24 which is disposed as shown within said chamber, and an integral, manually operable handle 26 which extends therefrom to without the housing 12.
  • the manually operable member 22 is preferably made from the same electrically insulative material as the housing 12,. and is manually pivotally movable through manual actuation of the handle 12 from the FIG. 1 portion thereof wherein the circuit breaker 10 is closed to the H6. 3 portion thereof wherein the breaker is in the manually open position thereof.
  • the member 22 is automatically pivotally movable upon overload tripping of the circuit breaker 10 from the FIG. 1 position thereof to the FIG. 2 position thereof wherein the breaker is in the automatically tripped, open position thereof.
  • a generally cylindrical, stepped boss 30 is moulded into the housing body 14 and extends as shown into chamber 17.
  • a latch arm 32 which is preferably made of steel and which is formed from a single appropriately configured strip which is bent over to provide the spaced, double-wall construction as most-clearly depicted in FIG. 5, is disposed as shown in the cavity 17 with one extremity thereof being pivotally connected to the boss 30 by th extension of the latter through a slightly oversized aperture 34 formed in said latch am.
  • the other extremity of the latch arm 32 terminates as shown in a generally triangular latch portion 36, and an adjacent notch 38 which, through cooperative association with a housing body-moulded.
  • stop 40 functions to determine the point at which the latch arm 32 is latched, again as discussed in greater detail hereinbelow.
  • Clearance for pivotal movement of the latch arm 32 about boss 30 is provided in part by a housing bodymoulded spacer rib 42 which spaces the former from the housing body.
  • a stop for counter clockwise pivotal movement of latch arm 32 about boss 30 is provided by a housing body-molded boss 29.
  • a pivot pin is formed as best seen in H0. on the latch arm 32 by a bent-over portion thereof.
  • a contact arm is indicated at 46 and is preferably made of copper or other suitable, highly electrically.
  • the contact arm 46 extends as shown between thespaced walls of the latch arm 32 and is fulcrumed or pivotally carried from the latter on pivot 44.
  • a generally T-shaped end portion 48 is formed as shown on the contact arm 46 and, upon pivotal movement of the contact arm 46 about the movable latch arm pivot 44, this end portion ismovable through an arc as generally defined by an arcuate cutout 50 in the member 22 and as limited by a housing body-moulded stop 52.
  • a contact 54 is carried as shown from the other end portion of the contact arm 46 and cooperates with a fixed contact 56 which is in turn carried by a housing-mounted conductor 58.
  • the conductor 58 terminates in a bayonet-type connector 60 which extends as shown from the housing 12 to enable the convenient connection of the circuit breaker on a circuit board.
  • v is cut from the latch member 64 extends as shown into 4
  • An over-center or over-toggle spring is indicated at 62 and is connected as shown to the member 22 and contact 46 by the extension of the respective, bent-over spring extremities into mounting apertures 61 and 63 provided therefor in said member and arm.
  • a latch member is indicated at 64 and is preferably made of a single piece of relatively thin strip steel which is formed as shown by appropriate bending thereof.
  • the latch member 64 is disposed as shown in the cavity 17 with freedom for pivotal movement in a V notch 69 in housing'12, and a strip spring 66 which cooperative association with a housing back-moulded boss 68 to spring bias the member 64 for clockwise rotation relative to its pivot in notch 69.
  • the bimetal strip 70 which is formed of two metals having dissimilar coefficients of thermal expansion and secured together in back-to-back relationship, is mechanically and electrically connected at one extremity thereof, as bywelding, to a copper conducting plate 72 which is in turn fixedly disposed in the housing 12 by tight friction fit between housing back-moulded bosses 74 and 76, and moulded-in pocket 77, to thus fixedly position strip 70.
  • a box-like connector is indicated at 78 and isfixedly disposed in the housing 12 by a fit between moulded housing bosses 80 and 82.
  • the plate 72 extends into and terminates in the connector 78.
  • a connection screw 84 extends into connector 78 and an aperture 86 is formed in the housing back 14 to enable the extension of a suitable conductor into the connector 78 for finn connection therewithin to plate 72 by tightening of connection screw 84 through housingback aperture 88.
  • a latch notch 90 having a small lip portion 92 is formed as shown in the latch member 70 and the extremity of the latch ann latch portion 36 may be seen to extend thereinto for latching when the breaker 10 is in the closed position thereof of FIG. 1.
  • a calibration screw mounting is provided by doubly bent over portions 91 and 93 of the latch member 64 and slightly misaligned threaded apertures formed therein.
  • a calibration screw 94 of any suitably nonconductive material is threaded as shown through said apertures and extends into surface contact with the bimetallic element whereby may be understood that clockwise rotation of said screw, as through housing back aperture 96, will function to move the latch member 64 closer to the bimetallic member 70, and vice versa.
  • the slight misalignment of the calibration screw mounting apertures in the springy material of latch member 64 will advantageously render the calibration screw particularly resistant to accidental loosening in OPERATION Withthe circuit breaker 10 on line and in the closed position thereof of FIG.
  • pivot pin 44 lies to right of an imaginary'line drawn between the respective ends of the over-toggle spring 62 at spring mounting apertures 61 and 63, and that there is a small gap between stop 52 and the adjacent leading contact arm edge I64.
  • bimetallic member 76 will respond by bowing to the right as seen in FIG. 1 with resultant generally pivotal movement of the latch member 64 in this same direction under the action of calibration screw 94.
  • the latch arm 32 is released from the latch notch 90 due to the movement of the latch member 64 away from the latch arm with the result that the support for the latch portion end of the latch arm disappears to thus free the latch for counter-clockwise pivotal movement about boss 30 under the spring-biased action of contact arm 46 against latch arm pivot 44.
  • the leading edge 104 of contact arm 46 will abut boss 52 to thus establish an artificial sliding pivot for the contactarm at said boss and initiate generally counter-clockwise pivotal movement of the contact arm about said sliding pivot.
  • the over-toggle spring 62 will be effective to rapidly pivotally move, in snap-action fashion, the contact arm 46 about pivot pin 44 from the position of the former in FIG. I to the FIG. 3 position thereof, as determined by the abutment of projection 51 of contact arm and portion 48 with boss 52, to separate the contacts 56 and 54 to the extent depicted in FIG. 3 and thus open the circuit breaker 10.
  • the distance between stop 40 and the latch member notch 90 is very substantially less than the distance between pivot 30 and said latch member notch, the effect of housing instability upon the essentially closely controlled relative disposition of latch member'latch portion 36 and the latching notch 90 is very substantially minimized in like manner.
  • the circuit breaker 10 is configured to have a stop 40 latching notch 90 distance of about one-tenth the distance between pivot pin'30 and said latching notch, it should be clear that the effects of dimensional instability of housing 12 upon breaker latching operation should be reduced by a factor of l0 to very significant advantage as should be obvious.
  • a further significant advantage of the minimization of the effects of housing dimensional instability on the latching operation of the circuit breaker l0 resides in the fact that the same enables unlatching of the latch arm 32- to occur accurately in response to very limited travel, for example 0.030 inch, of the latch member 64 to thereby provide for extremely precise breaker operation as should be obvious.
  • Assembly of the circuit breaker 10 is greatly simplified, to significant economic advantage, by the fact that all of "the operating breaker components lie substantially flat within the housing body 14 and may thus be readily and quickly inserted thereinwithout the use of specialized assembly fixtures or the like.
  • a circuit breaker comprising, a, housing, a latch arm, a latch member, cooperating latching means on said latch arm and said latch member for latching the former to the latter, means on" said housing for pivotally mounting-said latch arm relative to said latch member, locating means on said housing for locating said latch arm relative to said latch member at a location on the former between said pivotal mounting means and said latch arm to thereby reduce the effects of the dimensional instability of said housing upon the latching of said latch arm on said latch member.

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  • Breakers (AREA)
US00311283A 1972-12-01 1972-12-01 Latch mechanism for toggle actuated circuit breaker Expired - Lifetime US3818168A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
US00311283A US3818168A (en) 1972-12-01 1972-12-01 Latch mechanism for toggle actuated circuit breaker
CA185,574A CA982201A (en) 1972-12-01 1973-11-13 Circuit breaker with improved latch arm locating means
FR7342867A FR2209202B3 (enrdf_load_stackoverflow) 1972-12-01 1973-11-30
JP48135209A JPS4986879A (enrdf_load_stackoverflow) 1972-12-01 1973-11-30
IT54017/73A IT997837B (it) 1972-12-01 1973-11-30 Interruttore o ruttore di circuito
GB5584873A GB1424929A (en) 1972-12-01 1973-12-03 Circuit breaker

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00311283A US3818168A (en) 1972-12-01 1972-12-01 Latch mechanism for toggle actuated circuit breaker

Publications (1)

Publication Number Publication Date
US3818168A true US3818168A (en) 1974-06-18

Family

ID=23206212

Family Applications (1)

Application Number Title Priority Date Filing Date
US00311283A Expired - Lifetime US3818168A (en) 1972-12-01 1972-12-01 Latch mechanism for toggle actuated circuit breaker

Country Status (6)

Country Link
US (1) US3818168A (enrdf_load_stackoverflow)
JP (1) JPS4986879A (enrdf_load_stackoverflow)
CA (1) CA982201A (enrdf_load_stackoverflow)
FR (1) FR2209202B3 (enrdf_load_stackoverflow)
GB (1) GB1424929A (enrdf_load_stackoverflow)
IT (1) IT997837B (enrdf_load_stackoverflow)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0020312A1 (en) * 1979-06-01 1980-12-10 BASSANI TICINO S.p.A. Single-pole circuit breaker
US4968863A (en) * 1989-06-29 1990-11-06 Square D Company Unitary breaker assembly for a circuit breaker
EP0764959A3 (en) * 1995-09-20 2000-03-15 CAVIS S.r.l. Impact sensor for motor vehicles
US6160470A (en) * 1994-01-21 2000-12-12 O'carroll; Thomas Circuit breaker
US6265680B1 (en) * 1999-02-02 2001-07-24 The Whitaker Corporation Electrical circuit breaker having an insulation displacement connector assembly
US6414245B1 (en) * 2000-11-30 2002-07-02 Marconi Communications, Inc. Printed circuit board with bullet connector sockets
US20100052828A1 (en) * 2006-06-16 2010-03-04 Siemens Aktiengesellschaft Line circuit breaker and magnet yoke for a line circuit breaker

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2361848A (en) * 1942-01-13 1944-10-31 Arrow Hart & Hegeman Electric Circuit breaker
US2426880A (en) * 1942-03-23 1947-09-02 Square D Co Circuit breaker
US2627564A (en) * 1949-11-18 1953-02-03 Gen Electric Electric circuit breaker
US2917607A (en) * 1955-09-12 1959-12-15 Westinghouse Electric Corp Arc resistant molded members
US3287522A (en) * 1965-06-28 1966-11-22 Gen Electric Circuit breaker with spring-biased toggle link
US3288965A (en) * 1965-08-05 1966-11-29 Gen Electric Multiple circuit breaker assembly with common tripping

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2361848A (en) * 1942-01-13 1944-10-31 Arrow Hart & Hegeman Electric Circuit breaker
US2426880A (en) * 1942-03-23 1947-09-02 Square D Co Circuit breaker
US2627564A (en) * 1949-11-18 1953-02-03 Gen Electric Electric circuit breaker
US2917607A (en) * 1955-09-12 1959-12-15 Westinghouse Electric Corp Arc resistant molded members
US3287522A (en) * 1965-06-28 1966-11-22 Gen Electric Circuit breaker with spring-biased toggle link
US3288965A (en) * 1965-08-05 1966-11-29 Gen Electric Multiple circuit breaker assembly with common tripping

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0020312A1 (en) * 1979-06-01 1980-12-10 BASSANI TICINO S.p.A. Single-pole circuit breaker
US4968863A (en) * 1989-06-29 1990-11-06 Square D Company Unitary breaker assembly for a circuit breaker
WO1991000605A1 (en) * 1989-06-29 1991-01-10 Square D Company Unitary breaker assembly for a circuit breaker
US6160470A (en) * 1994-01-21 2000-12-12 O'carroll; Thomas Circuit breaker
EP0764959A3 (en) * 1995-09-20 2000-03-15 CAVIS S.r.l. Impact sensor for motor vehicles
US6265680B1 (en) * 1999-02-02 2001-07-24 The Whitaker Corporation Electrical circuit breaker having an insulation displacement connector assembly
US6414245B1 (en) * 2000-11-30 2002-07-02 Marconi Communications, Inc. Printed circuit board with bullet connector sockets
US20100052828A1 (en) * 2006-06-16 2010-03-04 Siemens Aktiengesellschaft Line circuit breaker and magnet yoke for a line circuit breaker
US7893797B2 (en) * 2006-06-16 2011-02-22 Siemens Aktiengesellschaft Line circuit breaker and magnet yoke for a line circuit breaker

Also Published As

Publication number Publication date
GB1424929A (en) 1976-02-11
IT997837B (it) 1975-12-30
FR2209202A1 (enrdf_load_stackoverflow) 1974-06-28
CA982201A (en) 1976-01-20
JPS4986879A (enrdf_load_stackoverflow) 1974-08-20
FR2209202B3 (enrdf_load_stackoverflow) 1976-10-15

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