US3810051A - Circuit breaker trip and latch mechanism - Google Patents

Circuit breaker trip and latch mechanism Download PDF

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Publication number
US3810051A
US3810051A US00345396A US34539673A US3810051A US 3810051 A US3810051 A US 3810051A US 00345396 A US00345396 A US 00345396A US 34539673 A US34539673 A US 34539673A US 3810051 A US3810051 A US 3810051A
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US
United States
Prior art keywords
trip
lever
latch lever
circuit breaker
latch
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
US00345396A
Other languages
English (en)
Inventor
E Walker
A Maier
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.)
Westinghouse Electric Corp
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
Priority to US00345396A priority Critical patent/US3810051A/en
Priority to ZA00741620A priority patent/ZA741620B/xx
Priority to CA194,839A priority patent/CA999902A/en
Priority to GB1196374A priority patent/GB1461814A/en
Priority to DE7409789U priority patent/DE7409789U/de
Priority to AU66858/74A priority patent/AU490009B2/en
Priority to DE2413499A priority patent/DE2413499A1/de
Priority to BE1005814A priority patent/BE812746A/fr
Priority to FR7410267A priority patent/FR2223824A1/fr
Priority to ES424701A priority patent/ES424701A1/es
Priority to BR2410/74A priority patent/BR7402410D0/pt
Priority to IT20867/74A priority patent/IT1012560B/it
Application granted granted Critical
Publication of US3810051A publication Critical patent/US3810051A/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
    • H01H71/505—Latching devices between operating and release mechanism
    • 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
    • H01H2071/506—Latching devices between operating and release mechanism using balls or rollers in the latching device
    • 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
    • H01H2071/508—Latching devices between operating and release mechanism with serial latches, e.g. primary latch latched by secondary latch for requiring a smaller trip force
    • 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
    • H01H71/74—Means for adjusting the conditions under which the device will function to provide protection
    • H01H2071/7481—Means for adjusting the conditions under which the device will function to provide protection with indexing means for magnetic or thermal tripping adjustment knob
    • 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
    • H01H71/128—Manual release or trip mechanisms, e.g. for test purposes

Definitions

  • This invention relates to a circuit breaker having a trip and latch mechanism responsive to thermal and magnetic forces.
  • Circuit breakers of the type disclosed in US. Pat. No. 3,530,414 comprise overcurrent protective devices that function satisfactorily for responding to such abnormal currents as overcurrents, ground fault currents, and short currents that occur in an electrical distribution system. Certain disadvantages have developed, however, with that type of construction including augmented size for operating parts with the development of additional overcurrent protective means.
  • a protective device for a circuit breaker which comrpises relatively movable contact means and means releasable to effect opening of said contact means
  • the releasable means including a releasable arm movable between latched and unlatched positions, a trip device operable to effect unlatching of the releasable arm, the trip device comprisingmagnetic trip means, a trip bar, a latch lever, and a trip lever, the atch lever being movable between latched and unlatched positions of the releasable arm and being biased in the latched position and being urged to the unlatched position by the releasable arm, the trip lever being movable between latched and unlatched positions of the latch lever and being in the latched position, the latch lever being retained in the latched position by the trip bar
  • the advantage of the device of this invention is that it reduces the latch load on the trip bar and enables the use of shorter levers and less force, which in turn provides for a more compact operative device.
  • FIG. 1 is -a vertical sectional view of a circuit breaker
  • FIG. 2 is a right elevational view of the trip device
  • FIG. 3 is a left elevational view of the trip device
  • FIG. 4 is a vertical sectional view taken on the line IVIV of FIG. 3;
  • FIG. 5 is a vertical sectional view taken on the line V-V of FIG. 3;
  • FIG. 6 is a plan view of the trip device shown in FIGS. 2-5.
  • FIG. 7 is a vertical sectional view taken on the line VII-VII of FIG. 4.
  • a circuit breaker is generally indicated at 3 and it comprises an insulating housing 5 and a circuit breaker mechanism 7 supported within the housing.
  • the housing 5 comprises an insulating base 9 and an insulating cover 11.
  • the circuit breaker mechanism 7 comprises an operating mechanism, and a latch and trip device 15. Except for the latch and trip device, the circuit breaker 3 is of the type that is generally described in the patent to Albert R. Cellerini et al., U.S. Pat. No. 3,287,534 issued Nov. 22, 1966.
  • the circuit breaker 3 is a threepole circuit breaker comprising three compartments disposed in side-by-side relationship, the center pole compartment (FIG. 1) is separated from the two outer pole compartments by insulating barrier walls formed with the housing base 9 and cover 11.
  • the operating mechanism 13 is disposed in the center pole compartment and is a single operating mechanism for operating .the contacts of all three pole units.
  • Each pole unit comprises a stationary contact 21 that is fixedly secured to a rigid main conductor 23 that in turn is secured to the base 9 by bolt 25.
  • a movable contact 27 is welded or brazed to a contact arm that is mounted on a switch arm 31 by a pivot pin 33.
  • the arms 29 and 31 for all three of the pole units are supported at one end thereof and rigidly connected on a common insulating tie bar 35 by which the arms of all three pole units move in unison.
  • Each of the contact arms 29 is biased about the associated pivot pin 33 by means of a spring 37 to provide contact pressure in the closed position.
  • the operating mechanism 13 actuates the switch arms 31 between open and closed positions.
  • the mechanism comprises a pivoted formed operating lever 39, a toggle comprising two toggle links 41 and 43, overcenter springs 45 and 47, and a pivoted releasable cradle or arm 49 controlled by the trip device 15.
  • An insulating shield 51 forsubstantially closing an opening 53 in the cover 11, is mounted on the outer end of the operating lever 39 and has an integral handle portion 55 extending out through the opening to enable manual operation of the breaker.
  • the toggle links 41 and 43 are pivotally connected together by a knee pivot pin 57.
  • the toggle link 41 is pivotally connected to the releasable arm 49 by a pin 59
  • the toggle link 43 is pivotally connected to the switch arm 31 of the center pole unit by a pin 61.
  • the overcenter springs 45 and 47 are connected under tension between the knee pivot pin 57 and the outer end of the operating lever 39.
  • the circuit breaker is manually operated to the open position by movement of the handle portion 55 in a counterclockwise direction to the off" position, which movement actuates the overcenter springs 45, 47 to collapse the toggle links 41 and 43 to the position shown in FIG. 1, and opening movement of the contact arm 29 for all of the pole units in a manner well known in the art.
  • the circuit breaker is manually closed by reverse movement of the handle portion 55 from the off" position to the on position, which movement causes the springs 45, 47 to move over center and straighten the toggle links 41, 43 thereby moving the contact arm 29, for all of the pole units, to the closed position as shown in broken line position.
  • the trip device serves to effect automatic release of the releasable cradle or arm 49 and opening of the breaker contacts for all of the pole units, in response to predetermined overload conditions in the circuit breaker through any or all pole units of the circuit breaker, in a manner described hereinbelow.
  • each pole unit extends from a right-hand terminal 63 through the conductor 23, the contacts 21, 27, the contact arm 29, a flexible conductor 65, that is secured to the contact arm 29, a conductor 67, a trip conductor 69, to a left-hand terminal connector 71.
  • Bolt means 73 secure one end of the trip conductor 69 to the conductor 67 and the other end of the trip conductor 69 is disposed between a backup plate 75 and the terminal 71 where it is secured in place by mounting bolt 77 of the terminal 71.
  • the latch and trip device 15 comprises a molded insulating housing base 81 and a molded insulating housing cover 79 secured to the base to enclose a molded insulating trip bar 83 that is common to all three of the pole units.
  • the base 81 includes a pair of spaced partitions 85 and 87 which are vertically disposed and integral with the base for separating the interior of the housing into three compartments, each compartment containing one of the three poles.
  • the cover 79 is provided with partitions corresponding to partitions 85 and 87 and have mating surfaces therewith in a manner similar to the mating surfaces of the peripheral surfaces of the base 81 and cover 79 as indicated by a parting line 89 (FIG. 6).
  • each section of the trip bar 83 located within the space compartments of the housing comprise upper and lower portions 83a and 83b, which are above and below the axis of rotation of the trip bar.
  • Each upper portion 83a is provided with an adjusting screw and nut assembly 99 which cooperates with a bimetal member 101 for adjusting the spacing between the upper ends of the bimetal member and the trip bar portion 83a in response to the degree of deflection of the upper end of the member 101 toward the member 7 83a, whereby the trip bar-83 is rotated clockwise by the bimetal member and thereby trips the circuit breaker to the open position.
  • the lower end portion 83b of the trip bar 83 is preferably provided with a drive screw 103 by which contact is made with an adjoining mem-' bet for similar rotation of the trip bar in the manner to be described hereinbelow.
  • the trip conductor 69 includes an inverted U-shaped intermediate portion 69a which constitutes a single loop of a stationary magnetic structure.
  • Stationary magnetic structure also comprises a magnetic core 105, a U-shaped frame 107 having a pair of spaced flanges 109 one of which is shown in FIG. 5, and an armature 111.
  • the assembly of the intermediate U-shaped portion 69a, the core 105, and the intermediate portion of the frame 107 together with the lower portion of the bimetal member 101 are secured in place by suitable means such as rivets 113 on the housing base 79.
  • the lower end portion of the bimetal member 101 is in surface to surface contact with the conductor 69, whereby upon the occurrence of a low persistent overload current below a predetermined value, of, for example, 10 times normal rated current, the bimetal member 101 is heated and deflects to the right through an air gap dependent upon the setting of the adjustment screw 99.
  • a predetermined value of, for example, 10 times normal rated current
  • the trip bar 83 is actuated to trip the circuit breaker.
  • the armature 111 is disposed between the space flanges 109 of the U-shaped frame 107 and is pivotally mounted therein to rotate about an axis 115 near the lower end of the armature.
  • the armature 111 is preferably mounted by suitable means such as rivets 117 on 'a support lever 119 having oppositely extending out-turned lugs 121 which are seated in corresponding openings 123 in the flanges 109.
  • Each flange 109 is also provided with a V-shaped notch 125 into which edge portions of the lever 119 and armature 11] extend. The notches 125 thereby limit movement of the assembly of the lever 119 and armature 111 when the armature is attracted toward the core 105.
  • a lever 129 having a lower end disposed over the upper end of the lever 119 is mounted within the housing and is provided with calibration means including a calibration screw 131 at the upper end of the lever 129. As shown in FIG.
  • each lever 129 includes a notch 133 on each opposite side thereof which notch is seated in corresponding projections 135 of the housing base 79 where the levers 129 are retained in place by the cover 81.
  • An adjusting knob 137 is seated within the top end of the housing base and is provided with a lower end portion having a cam surface. Inasmuch as the lever 129 is biased counterclockwise about its pivot point by the spring 127 of the lower lever 119 the calibration 131 rides on the cam surface of the lower portion 139 of the adjusting knob 137.
  • each adjusting knob 137 includes a flange 141, the lower surface of which includes spaced notches 143.
  • An index member 145 is disposed below the flange 143 and is provided with a projection 147 for engaging one of the spaced notches 143 as the calibrating screw 136 is rotated to the desired position. Accordingly, the desired spacing between the armature 111 and the core 105 is established by rotation of the adjusting knob 137.
  • a removable flexible shield 149 is disposed in an access opening 151 of the cover 79 in order to turn the calibrating screw 131 and 99. When the calibration is made, the shield 149 is replaced in the opening.
  • the mechanism by which the releasable arm 49 is released is shown in FIG. 2, 4 and 6.
  • the mechanism includes the trip bar 83, a trip lever 153 and a latch lever 155.
  • a U-shaped mounting frame 157 is mounted on the base 79 with spaced upright sides 157a and 157b providing mounting support for the levers.
  • the trip lever 153 includes a U-shaped portion 159 at the lower end which portion is mounted on a pivot pin 161 which extends from the side 157a of the frame.
  • the U-shaped lower portion of the lever maintains the lever upright adjacent the frame side 1570.
  • the upper end of the trip lever 153 includes a flange 163 which engages a notch 165 on the trip bar 83. As shown in FIG. 4 a portion of the trip bar extends through an opening 167 in the insulating base 79.
  • the latch lever 155 includes down-turned portions 155a and 15512 which are mounted on a pivot pin 169 the opposite ends of which are secured in the sides 157a and 157b of the frame 157.
  • a spring 171 is mounted on the pin 169 and has end portions engaging the levers 153 and 155 for biasing the levers in the latched positions.
  • the latch lever 155 is prevented from turning due to engagement of the lower end of the lever on a roller or rotating pin 175 which is mounted in the U-shaped portion 159 of th trip lever 153.
  • the trip lever 153 is biased clockwise and is prevented from movement by engaging of the flange 163 in the notch 165 of the trip bar 83.
  • the trip bar is rotated clockwise, the flange 163 is dislodged from the latch position within the notch 165 and the trip lever 153 rotates clockwise to move the roller 175 from engagement with the lower end of the latch lever 155.
  • the latch lever 155 is free to rotate about the pin 169 and thereby unlatch the releasable arm 49 from th latched position.
  • the roller 175 moves from engagement with latch lever 155, the roller rotates and thereby minimizes friction between these parts.
  • the length of the levers can be shortened as compared with levers used with a nonrotating pin; and a more compact structure is obtained.
  • a projection 177 extends from the upper corner of the trip bar portion 83a, which projection is aligned with an aperture 179 in the housing base 79.
  • the trip bar may be tripped manually.
  • the device of the present invention provides a new and novel trip device for a circuit breaker which is of a more compact size than the previous trip devices of the same rating.
  • the advantage of the smaller dimensions is due primarily to the use of lever means having smaller space requirements than magnetic tripping devices of prior construction.
  • the outer dimensions of the circuit breaker housing may also be reduced for circuit breakers of the same rating.
  • a circuit breaker comprising relatively movable contact means and means releasable to effect automatic opening of said contact means, the releasable means including a releasable arm movable between latched and unlatched .positions, a trip device operable to effect unlatching of the releasable arm, the trip device comprising magnetic trip means, a trip bar, a latch lever, and a trip lever, the latch lever being movable between latched and unlatched positions of the releasable arm an being biased in the latched position and being urged to the unlatched position by the releasable arm, the trip lever being movable between latched and unlatched positions of the latch lever and being biased in the latched position, the trip lever being retained in the latched position by the trip bar, a pin rotatably mounted on the trip lever and located in the path of movement of the latch lever to retain the latch lever in the latched position when the trip bar

Landscapes

  • Breakers (AREA)
  • Driving Mechanisms And Operating Circuits Of Arc-Extinguishing High-Tension Switches (AREA)
  • Trip Switchboards (AREA)
US00345396A 1973-03-27 1973-03-27 Circuit breaker trip and latch mechanism Expired - Lifetime US3810051A (en)

Priority Applications (12)

Application Number Priority Date Filing Date Title
US00345396A US3810051A (en) 1973-03-27 1973-03-27 Circuit breaker trip and latch mechanism
ZA00741620A ZA741620B (en) 1973-03-27 1974-03-12 An improvement in or relating to circuit breaker trip and latch mechanism
CA194,839A CA999902A (en) 1973-03-27 1974-03-13 Circuit breaker trip and latch mechanism
GB1196374A GB1461814A (en) 1973-03-27 1974-03-18 Circuit breaker trip and latch mechanism
AU66858/74A AU490009B2 (en) 1973-03-27 1974-03-20 Improvements in or relating to circuit breaker trip and latch mechanism
DE2413499A DE2413499A1 (de) 1973-03-27 1974-03-20 Ueberstrom-schutzschalter
DE7409789U DE7409789U (de) 1973-03-27 1974-03-20 Überstromschutzschalter
BE1005814A BE812746A (fr) 1973-03-27 1974-03-22 Mecanisme de declenchement et de verrouillage pour disjoncteur
FR7410267A FR2223824A1 (fr) 1973-03-27 1974-03-26
ES424701A ES424701A1 (es) 1973-03-27 1974-03-27 Mejoras introducidas en disyuntores que comprenden un meca-nismo de accionamiento de contactos.
BR2410/74A BR7402410D0 (pt) 1973-03-27 1974-03-27 Disjuntor
IT20867/74A IT1012560B (it) 1973-03-27 1974-04-08 Interruttore elettrico con mecca nismo di aggancio

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00345396A US3810051A (en) 1973-03-27 1973-03-27 Circuit breaker trip and latch mechanism

Publications (1)

Publication Number Publication Date
US3810051A true US3810051A (en) 1974-05-07

Family

ID=23354874

Family Applications (1)

Application Number Title Priority Date Filing Date
US00345396A Expired - Lifetime US3810051A (en) 1973-03-27 1973-03-27 Circuit breaker trip and latch mechanism

Country Status (10)

Country Link
US (1) US3810051A (fr)
BE (1) BE812746A (fr)
BR (1) BR7402410D0 (fr)
CA (1) CA999902A (fr)
DE (2) DE2413499A1 (fr)
ES (1) ES424701A1 (fr)
FR (1) FR2223824A1 (fr)
GB (1) GB1461814A (fr)
IT (1) IT1012560B (fr)
ZA (1) ZA741620B (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5142259A (en) * 1991-05-16 1992-08-25 General Electric Company Molded case circuit breaker with low friction latch arrangement
US6472971B2 (en) * 2000-03-06 2002-10-29 Fuji Electric Co., Ltd. Circuit breaker
EP2472550A1 (fr) 2010-12-29 2012-07-04 ABB Technology AG Appareil de verrouillage et mécanisme de fonctionnement avec un tel appareil de verrouillage
EP3316275A1 (fr) 2016-10-25 2018-05-02 ABB Schweiz AG Dispositif de verrouillage et mécanisme de fonctionnement doté d'un tel dispositif de verrouillage

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2051224A (en) * 1935-08-02 1936-08-18 Rape Alvin Continuous rail
US2794881A (en) * 1954-07-22 1957-06-04 Gen Electric Circuit breaker operating mechanism
US3460075A (en) * 1967-03-07 1969-08-05 Westinghouse Electric Corp Circuit breaker with improved latch and trip structures
US3657672A (en) * 1970-09-24 1972-04-18 Westinghouse Electric Corp Circuit breaker with manual trip structure

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2051224A (en) * 1935-08-02 1936-08-18 Rape Alvin Continuous rail
US2794881A (en) * 1954-07-22 1957-06-04 Gen Electric Circuit breaker operating mechanism
US3460075A (en) * 1967-03-07 1969-08-05 Westinghouse Electric Corp Circuit breaker with improved latch and trip structures
US3657672A (en) * 1970-09-24 1972-04-18 Westinghouse Electric Corp Circuit breaker with manual trip structure

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5142259A (en) * 1991-05-16 1992-08-25 General Electric Company Molded case circuit breaker with low friction latch arrangement
US6472971B2 (en) * 2000-03-06 2002-10-29 Fuji Electric Co., Ltd. Circuit breaker
EP2472550A1 (fr) 2010-12-29 2012-07-04 ABB Technology AG Appareil de verrouillage et mécanisme de fonctionnement avec un tel appareil de verrouillage
WO2012089550A1 (fr) 2010-12-29 2012-07-05 Abb Technology Ag Appareil de verrouillage, et mécanisme fonctionnel utilisant un tel appareil de verrouillage
US8629743B2 (en) 2010-12-29 2014-01-14 Abb Technology Ag Latching apparatus and an operating mechanism with such a latching apparatus
EP3316275A1 (fr) 2016-10-25 2018-05-02 ABB Schweiz AG Dispositif de verrouillage et mécanisme de fonctionnement doté d'un tel dispositif de verrouillage
WO2018077556A1 (fr) 2016-10-25 2018-05-03 Abb Schweiz Ag Dispositif de verrouillage et mécanisme d'actionnement doté d'un tel dispositif de verrouillage
US10937618B2 (en) 2016-10-25 2021-03-02 Abb Power Grids Switzerland Ag Latching device and an operating mechanism with such a latching device

Also Published As

Publication number Publication date
GB1461814A (en) 1977-01-19
BR7402410D0 (pt) 1974-11-19
ZA741620B (en) 1975-02-26
ES424701A1 (es) 1976-10-16
FR2223824A1 (fr) 1974-10-25
AU6685874A (en) 1975-09-25
DE2413499A1 (de) 1974-10-10
IT1012560B (it) 1977-03-10
CA999902A (en) 1976-11-16
BE812746A (fr) 1974-09-23
DE7409789U (de) 1974-07-18

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