US2993105A - Circuit breaker - Google Patents

Circuit breaker Download PDF

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Publication number
US2993105A
US2993105A US702576A US70257657A US2993105A US 2993105 A US2993105 A US 2993105A US 702576 A US702576 A US 702576A US 70257657 A US70257657 A US 70257657A US 2993105 A US2993105 A US 2993105A
Authority
US
United States
Prior art keywords
contact
lingers
circuit breaker
terminal
arc
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
US702576A
Other languages
English (en)
Inventor
Russell E Frink
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 US702576A priority Critical patent/US2993105A/en
Priority to DEW24620A priority patent/DE1115808B/de
Priority to JP3557058A priority patent/JPS349027B1/ja
Priority to US57320A priority patent/US3210506A/en
Application granted granted Critical
Publication of US2993105A publication Critical patent/US2993105A/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
    • H01H1/00—Contacts
    • H01H1/12—Contacts characterised by the manner in which co-operating contacts engage
    • H01H1/36—Contacts characterised by the manner in which co-operating contacts engage by sliding
    • H01H1/42—Knife-and-clip contacts
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/02—Details
    • H01H33/04—Means for extinguishing or preventing arc between current-carrying parts
    • H01H33/12—Auxiliary contacts on to which the arc is transferred from the main contacts
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
    • H01H9/30—Means for extinguishing or preventing arc between current-carrying parts
    • H01H9/38—Auxiliary contacts on to which the arc is transferred from the main contacts
    • H01H9/386—Arcing contact pivots relative to the fixed contact assembly

Definitions

  • An object of the invention is to provide a circuit breaker embodying an improved contact structure that is compact and has a high momentary and continuous current-carrying capacity.
  • Another object of the invention is to provide a circuit breaker embodying an improved contact structure having high interrupting and current-carrying capacities.
  • Another object of the invention is to provide a circuit breaker embodying an improved contact structure having main, secondary and arcing contacts for heavy duty, which contact structure is so compact that all of the separating contacts may be located within an arc chute to prevent the arc from restriking outside of the arc chute where it will not be extinguished.
  • the invention has been illustrated by showing a contact structure and mounting arrangement therefor, designed for a magnetic air circuit breaker having a momentary current rating of 100,000 amperes, a continuous current-carrying rating of 3,000 amperes, and an interrupting rating of 50,000 amperes, but the invention may be used with advantage in circuit breakers of other ratings.
  • Another object of the invention is to mount the contact structure on insulated terminal studs having a compact and eicient arrangement for conducting the heavy currents to the contacts.
  • FIG. 1 is a side elevational view, partly in section, of a circuit breaker embodying the principles of the invention.
  • FIG. 2 is an enlarged elevational view, partly in section, showing the improved contact structure in the closedcontact position
  • FIG. 3 is a horizontal sectional View taken through the contact structure on line III-III of FIG. 2;
  • FIG. 4 is a front elevational view of the stationary contact structure
  • FIG. 5 is an elevational sectional view through the stationary contact structure taken on line V-V of FIG. 4;
  • FIG. 6 is a side elevational view showing one of the terminal studs having contact fingers thereon for plugging the breaker into a cubicle;
  • FIG. 7 is a vertical sectional view taken through one of the terminal studs.
  • FIG. 8 is an elevational sectional view taken on line VIII-V111 of FIG. 1 and showing the terminal studs and the mounting means therefor.
  • the invention is illustrated as applied to a circuit breaker of the general type disclosed in Patent No. 2,717,292, issued September 6, 1955, to Russell E. Frink and Paul Olson and assigned to the assignee of the present invention.
  • the circuit breaker shown in the aforementioned patent is of the roll-out type and is mounted on a wheeled truck to facilitate movement of the breaker into and out of a cubicle in order to connect and disconnect the breaker in an electrical circuit.
  • the circuit breaker A is of the three pole type (only one pole being shown) and is mounted in a rigid frame comprising spaced triangular side plates 11 (only one being shown) rigidly secured together by cross members 13, 15, 17 and 19 to form a rigid frame.
  • the frame, together with the circuit breaker, is mounted on wheels 20 to facilitate rolling the breaker into and out of a cubicle.
  • the circuit breaker comprises generally a set of separable contact means 21 for each pole, a common operating mechanism 23, a trip device 25 and closing means 27.
  • the contact structure comprises generally a stationary contact assembly ⁇ 29 rigidly mounted on the inner end of an upper terminal stud 31 of hollow rectangular shape.
  • the terminal stud 31 is encased in insulating material 33 and is rigidly clamped by means of bolts 35 between supporting aluminum cross bars 37 which extend across the three poles of the breaker and are secured by means of bolts 39 to the spaced side plates 11 of the frame.
  • the contact structure also includes a movable switch arm 41 pivotally supported on a casting 43 rigidly secured to the inner end of a lower terminal stud 45 which also is of hollow rectangular shape.
  • the lower terminal stud 45 (FIGS. 7 and 8) is surrounded by insulating material 47 and is rigidly clamped between supporting cross bars 49 by means of bolts 51.
  • the cross bars 49 extend across all of the poles and are secured to the side plates 11 by means of bolts 53 (FIG. 8).
  • the terminal studs 31 and 45 are made hollow to provide ⁇ greater conductivity by reduction of the skin effect. A substantial reduction in the overall height of the breaker is effected by making the terminal studs rectangular rather than round, and supporting them between the cross bars 37 and 49 eliminates metal anges on the bushings.
  • the movable switch arm consists of two pairs of arms 55 and 57 (FIG. 3) bolted together at their upper ends by means of bolts 58 (FIG. 2) with a movable contact member 59 between them.
  • the lower ends of the pairs of switch arms 55 and 57 are spaced apart -as shown in FIG. 3 and each pair is pivotally supported by means of pins 61 (only one being shown) supported in projection 63 (FIGS. 1 and 2) on the casting 43.
  • Spring washers 65 disposed on the outer sides of each pair of switch arms 55 and 57 provide good contact pressure between the switch arms and the projections 63.
  • the movable switch member 59 has an arcing contact 67 (FIG. 2) rigidly secured to the upper end thereof and a secondary contact 69 rigidly secured thereto adjacent the lower end thereof.
  • Arc resisting main movable contact strips 71 are rigidly secured to the opposite edges of the contact member 59 for engagement with main stationary contact fingers 73.
  • the stationary contact assembly 29 is mounted on a conducting block 75 rigidly secured to the inner end of the upper terminal stud 31 and comprises a plurality of stationary contact lingers 73 and a plurality of stationary contact lingers 77 which at their upper ends Ihave stationary arcing contacts 79 rigidly mounted thereon for cooperating with the movable arcing contact 67.
  • Stationary secondary contacts 81 are mounted on the lower ends of the lingers 77.
  • Each of the main stationary contact ⁇ lingers 73 has an a-rc resisting contact 83 rigidly secured thereto for cooperating with the movable main contact strips 71.
  • the main stationary contac-t ngers 73 are biased inwardly to provide pressure by springs 85 surrounding rods 87 which extend horizontally through openings in the contact lingers 73 and through an opening in a contact support member 89 rigidly secured to the block 75.
  • the springs 85 are compressed between the contact lingers 73 and washers 91 which are retained in place by nuts 93 threaded onto the outer ends of the rods 87.
  • the springs 85 press rounded inner ends of the main contact lingers against the contact support member 89 to provide good electrical contact.
  • Each of the contact lingers 73 is provided with an inwardly projecting portion 95 which extends into recesses 97 in the contact support members 89 to preve-nt longitudinal movement of the lingers.
  • the main contact lingers 73 are positioned in two vertical opposed rows, with half of the lingers in each row. "I 'he length of the rows runs, in the same genera-l direction as the length of the moving switch arm and in the same direction as the height, rather than the width of the arc chute. This keeps the lwidth of the s-tationary contact assembly to a minimum and makes it possible to position the main contacts within the arc chute, in spite of the large number of main contact members required for the heavy currents.
  • the contact lingers 77 are pivotally and slidably supported at their lower ends by a rod 103 having its end supported in slots 1115 (FlG. 2) in forwardly extending projections 167 of a cage 99.
  • the contact fingers 77 are provided with openings 109 which are larger than the diameter of the rod 193 to provide for individual movement of the contac-t lingers.
  • Flexible conductors I111 secured by means of bolts 113 to the Contact lingers 77 and by bolts 115 to the contact support member 89 elec,- trically connect the lingers 77 through the member 89 and the block 75 to the terminal stud 31.
  • the upper ends of the contact lingers 77 are controlled in their movement by a rod 117 (FIGS. 2, 4 and 5) extending through ropenings 119 in the fingers.
  • the openings 11'9 are somewhat larger than the diameter of the rod 117 to provide for individual movement of the lingers 77.
  • the ends of the rod 117 engage in enlarged slots 12H1 (FIG. 2) in projections 123 of the retaining cage 99 and the rod 117 is retained in position by small retaining plates 125 secured to opposite sides of the projection I123 by means of bolts 127 and engaging the ends of the rod 117.
  • the lower ends of the contact lingers 77 are individually biased for secondary contact pressure by means of springs 129 compressed between spring seats in the retaining cage 99 and spring guides 131 on the contact lingers.
  • the upper ends of the contact lingers 77 are biased by a pair of springs 133 (FIG. 5) compressed be.
  • a pressure equalizing member 139 in the shape of an equilateral triangle is provided with ⁇ a projection 141 on each of its apices which engage in notches 143 in the contact lingers 77.
  • the equalizer 139 is also provided with a socket (not shown) at its geometric center which is engaged by a projection (also not shown) on the movable spring seat 137.
  • the upper projection 1.41 on the pressure equalizer 139 engages a notch 143 in the center one of the con4 tact lingers 77 and the lower projections engage the notches 143 yfor the outer lingers 77 thus equalizing the pressure of the springs 133 on all three of the fingers 77.
  • the use of the spring-biased main, secondary and arcing contacts, as at 73, 81 and 79, all on the stationary Contact assembly, has the advantage that the moving con tact assembly is greatly simplified in that one rigid structure includes the mo-ving main, secondary and arcing contacts, which may all be brazed to a common contact member.
  • the main contact surfaces 71, the secondary contact surfaces 69 and arcing contact surfaces 67 are rigid with each other and with the moving switch arm 57, and there is no need on the moving contact assembly for any biasing springs, any sliding contact surfaces, or any flexible current conductors.
  • Each of the terminal studs 31 and 45 are provided With a plurality of pair-s of spring biased contact lingers 145 as shown in FIG. 6, for engaging lixed contacts 147 having flat side surfaces to connect the breaker in an electrical circuit.
  • each of the two opposed parallel sides of the rectangle may directly support a plurality of pairs of the opposed Contact lingers in a straight row without the use of any intermediate member in the current path. This is true of both of the terminal studs 31 and 45. This keeps the number of joints in the current path to a minimum and facilitates the carrying of heavy currents.
  • the outer contact finger 145 of each pair in the row directly engages at its inner end with the outer surface of one side of the hollow rectangle and the inner linger of each pair in each row similarly engages the inner surface of one side of the hollow rectangle.
  • the movable switch arm 41 (FIG. 1) for operating the movable contacts (there being a switch arm 41 for each pole of the breaker) is operatively connected by means of an insulating operating rod 149 to the operating mechanism 23.
  • the upper ends of the operating rods 149 are pivotally connected by means of pivot pins 151 to the corresponding switch arms 41, and the lower ends of the operating rods are connected by suitable means to an angular crossbar 153 which is common to all of the poles of the breaker.
  • the crossbar 153 is pivotally connected at its ends by pivot pins 155 (only one being shown) to an operating lever 161 which is pivotally mounted on a shaft 167 supported in the side members of a generally U-shaped frame 169.
  • the frame 169 is supported on the cross members 13, 17 and 19 and is shown partly broken away more clearly to show the operating mechanism.
  • the operating mechanism consists of a closing lever 171 also pivotally mounted on the shaft 167 and connected by means of a link 173 to the moving armature 175 of the closing solenoid 27.
  • the operating lever 161 and the closing lever 171 are connected by means of an underset thrust-transmitting toggle comprising toggle links 177 and 179 which are pivotally connected together by a knee pivot pin 181.
  • the toggle link 177 is pivotally connected to the operating lever v161 and the toggle link ⁇ 174 is pivotally connected to the closing lever 1'77
  • the closing lever 171 is held in the closed position by a spring biased latch 183 which normally engages a roller 185 on the closing lever 171 and holds the latter in the position shown.
  • the toggle 177 and 179 is releasably held in a slightly underset position by a latch member 187 mounted on the shaft 167 for rotary movement relative thereto.
  • a link 189 connects the latch member 187 to the knee of the toggle 177-179 and the latch member is normally releasably held in latching position by the latching and tripping mechanisms 25 thus holding the toggle 177- 179 in thrust-transmitting position.
  • the latch member 187 is held in latching position by an intermediate slip-off latch 191 which, in turn, is held in latching position by a trigger latch 193.
  • a tripping electromagnet 195 is provided to operate the latch mechanism and elect release of the operating mechanism and opening of the breaker.
  • the tripping electromagnet 195 When an overload current occurs, the tripping electromagnet 195 is energized and operates the latch mechanism to eect release of the latch member 187. Upon release of the latch member 187, the toggle 177--179 c01- lapses permitting clockwise rotation of the operating lever 161 and opening movement of the switch arms 41 for the several poles of the breaker.
  • the toggle 177--179 automatically is reset to thrust-transmitting position and the latch member 187 is reset and relatched. This is effected by spring means 197 which is connected under tension between the armature 175 of the closing solenoid 27 and the closing lever 171 at a point near the shaft 167.
  • spring means 197 which is connected under tension between the armature 175 of the closing solenoid 27 and the closing lever 171 at a point near the shaft 167.
  • the separating contacts are all disposed well within an arc-extinguishing structure indicated generally at 205 (FIGS. 1 and 2) so that when the contacts separate and the moving contact means moves to the full open position, the arc drawn between the separating arcing contacts is drawn into the arc-extinguishing structure where it is quickly extinguished.
  • the arc extinguisher 205 may be of the general type shown in Dickinson and Frink Patent No. 2,442,199, issued May 25, 1948, or in Frink Patent No. 2,769,065, issued October 30, 1956.
  • the arc-extinguisher 205 is pivotally mounted by means of spaced brackets 207 (only one being shown) secured to the upper crossbar 37 by the bolts 35 which clamp the upper terminal stud in position.
  • the invention provides an improved contact structure which increases the momentary and continuous currentcarrying capacity in a small, compact contact arrangement which permits placing the entire separating contact structure inside the arc chute, hence, any restrking of the arc will occur between the contact structure and will be confined within the arc-extinguisher.
  • a frame comprising spaced side members, a pair of terminal members of hollow rectangular cross section, spaced cross bars mounted on and extending between said spaced side members, means rigidly clamping said terminal members between said crossbars, movable contact means pivotally mounted on the inner end of one of said terminal members, a stationary contact structure mounted on the inner end of the other of said terminal members, said stationary contact structure comprising a contact support member, a plurality of pairs of main stationary contact members disposed on opposite sides of said support member, a plurality of intermediate stationary contact members disposed between said pairs of main stationary contact members, and said movable contact means cooperating with said stationary contact structure to open and close said circuit.
  • a frame a terminal member of hollow rectangular cross section, insulating material around the terminal member and having at opposed outer surfaces, a pair of spaced cross bars clamped against the said at opposed outer surfaces of the insulating material and securing the hollow rectangular terminal member to the frame, a contact structure supported on the inner end of the terminal member, and two rows of opposed pairs of Contact ngers supported on the outer end of the terminal member.
  • a frame In a circuit breaker, a frame, one or more pairs of terminal members of hollow rectangular cross section, insulating material around each terminal member and having at opposed outer surfaces, spaced cross bars clamped against the said flat opposed outer surfaces of the insulating material and securing the hollow rectangular terminal members to the frame, movable and stationary contact structures supported on the inner ends of said terminal members of hollow rectangular cross section, two rows of opposed pairs of contact ngers supported on the outer end of each of said terminal members, each pair of contact ngers in one row having a iinger engaging the outer surface of one side of the associated hollow rectangle and another finger engaging the inner surface of the same side of the associated hollow rectangle, and each pair of contact fingers in the other row having a finger engaging the outer surface of another side of the associated hollow rectangle and another finger engaging the inner surface of the same other side of the associated hollow rectangle.

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  • Arc-Extinguishing Devices That Are Switches (AREA)
  • Breakers (AREA)
US702576A 1957-12-13 1957-12-13 Circuit breaker Expired - Lifetime US2993105A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US702576A US2993105A (en) 1957-12-13 1957-12-13 Circuit breaker
DEW24620A DE1115808B (de) 1957-12-13 1958-12-09 Ausschalter
JP3557058A JPS349027B1 (OSRAM) 1957-12-13 1958-12-12
US57320A US3210506A (en) 1957-12-13 1960-09-20 Circuit breaker with improved contact structure

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US702576A US2993105A (en) 1957-12-13 1957-12-13 Circuit breaker

Publications (1)

Publication Number Publication Date
US2993105A true US2993105A (en) 1961-07-18

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Family Applications (1)

Application Number Title Priority Date Filing Date
US702576A Expired - Lifetime US2993105A (en) 1957-12-13 1957-12-13 Circuit breaker

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US (1) US2993105A (OSRAM)
JP (1) JPS349027B1 (OSRAM)
DE (1) DE1115808B (OSRAM)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4309580A (en) * 1979-06-07 1982-01-05 Westinghouse Electric Corp. Dual arcing contacts for circuit breaker

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1843804A (en) * 1929-05-28 1932-02-02 Reyrolle A & Co Ltd Contact for electric circuit-breakers and the like
US1978246A (en) * 1933-03-31 1934-10-23 Gen Electric Electric circuit breaker
GB535461A (en) * 1939-03-11 1941-04-09 Westinghouse Electric Int Co Improvements in or relating to electric high voltage air circuit breakers
US2324891A (en) * 1941-05-01 1943-07-20 Gen Electric Electric circuit interrupter
US2426387A (en) * 1944-04-04 1947-08-26 Ite Circuit Breaker Ltd Circuit breaker contact
US2644875A (en) * 1948-07-01 1953-07-07 Roller Smith Corp Air circuit breaker
US2646482A (en) * 1947-01-11 1953-07-21 Ite Circuit Breaker Ltd High-voltage circuit breaker
US2708699A (en) * 1952-01-02 1955-05-17 Allis Chalmers Mfg Co Finger contact structure for circuit interrupting device
US2717292A (en) * 1952-04-18 1955-09-06 Westinghouse Electric Corp Air circuit breaker
US2761040A (en) * 1954-05-17 1956-08-28 Bbc Brown Boveri & Cie Lever-actuated switch
US2849579A (en) * 1956-07-31 1958-08-26 Westinghouse Electric Corp Contact structure

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE508906C (de) * 1930-10-03 Voigt & Haeffner Akt Ges Unterbrechungskontakt fuer grosse Stromstaerken, bestehend aus einem Haupt- und einem Abreisskontakt

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1843804A (en) * 1929-05-28 1932-02-02 Reyrolle A & Co Ltd Contact for electric circuit-breakers and the like
US1978246A (en) * 1933-03-31 1934-10-23 Gen Electric Electric circuit breaker
GB535461A (en) * 1939-03-11 1941-04-09 Westinghouse Electric Int Co Improvements in or relating to electric high voltage air circuit breakers
US2324891A (en) * 1941-05-01 1943-07-20 Gen Electric Electric circuit interrupter
US2426387A (en) * 1944-04-04 1947-08-26 Ite Circuit Breaker Ltd Circuit breaker contact
US2646482A (en) * 1947-01-11 1953-07-21 Ite Circuit Breaker Ltd High-voltage circuit breaker
US2644875A (en) * 1948-07-01 1953-07-07 Roller Smith Corp Air circuit breaker
US2708699A (en) * 1952-01-02 1955-05-17 Allis Chalmers Mfg Co Finger contact structure for circuit interrupting device
US2717292A (en) * 1952-04-18 1955-09-06 Westinghouse Electric Corp Air circuit breaker
US2761040A (en) * 1954-05-17 1956-08-28 Bbc Brown Boveri & Cie Lever-actuated switch
US2849579A (en) * 1956-07-31 1958-08-26 Westinghouse Electric Corp Contact structure

Also Published As

Publication number Publication date
JPS349027B1 (OSRAM) 1959-10-08
DE1115808B (de) 1961-10-26

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