US2215792A - Circuit breaker - Google Patents

Circuit breaker Download PDF

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Publication number
US2215792A
US2215792A US163212A US16321237A US2215792A US 2215792 A US2215792 A US 2215792A US 163212 A US163212 A US 163212A US 16321237 A US16321237 A US 16321237A US 2215792 A US2215792 A US 2215792A
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United States
Prior art keywords
contacts
circuit
breaker
latch
electromagnet
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
US163212A
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English (en)
Inventor
Oliver S Jennings
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.)
CBS Corp
Original Assignee
Westinghouse Electric and Manufacturing 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 Westinghouse Electric and Manufacturing Co filed Critical Westinghouse Electric and Manufacturing Co
Priority to US163212A priority Critical patent/US2215792A/en
Priority to DES133782D priority patent/DE721791C/de
Application granted granted Critical
Publication of US2215792A publication Critical patent/US2215792A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H75/00—Protective overload circuit-breaking switches in which excess current opens the contacts by automatic release of mechanical energy stored by previous operation of power reset mechanism
    • H01H75/02—Details
    • H01H75/04—Reset mechanisms for automatically reclosing a limited number of times
    • H01H75/06—Reset mechanisms for automatically reclosing a limited number of times effecting one reclosing action only
    • 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
    • H01H71/46—Automatic release mechanisms with or without manual release having means for operating auxiliary contacts additional to the main contacts

Definitions

  • the invention relates in general to circuit breakers and is particularly concerned with circuit breakers of the type used for controlling lighting and moderate power distribution feeder 5 circuits.
  • An objectv of the invention is the provision of an improved circuit breaker which is operable to automatically open the ⁇ circuit in response to an overload or abnormal condition and which will automatically reclose itself when, and only when, the condition causing the overload is removed or cleared from the controlled circuit.
  • Another object of the invention is theI provision of a circuit breaker of the type mentioned which is simple and inexpensive to manufacture and which is .safe and reliable in operation.
  • Another object of the invention is the provision of a circuit breaker of the above-mentioned type that is both manually operable and automatically operable to open and reclose the circuit.
  • Figure 1 is a vertical sectional view o f an automatic circuit breaker embodying the features of the invention, the various parts being shown in the positions they occupy when the breaker is closed;
  • Fig. 2 is a vertical sectional view of the circuit breaker, similar to Fig. 1, showing the parts in tripped open position following the occurrence of an overload of predetermined magnitude and duration;
  • Fig. 3 is a vertical sectional view of the circuit breaker, similar to Fig. 2, showing the position of the parts in the tripped open position following the occurrence of an overload, the latch means being shown in the operative position in which it prevents reclosing of the breaker;
  • Fig. 4 isa horizontal sectional view'of the circuit breaker shown in Fig. 1, taken on the line IV-IV of Fig. yl;
  • Fig. 5 is a schematic diagram illustrating the circuit which it controls
  • Fig. 6 is a vertical sectional view of a modified form'of automatic circuit'breaker which includes means 'for manually opening and closing the contacts of the breaker;
  • FIG. 7 is a horizontal sectional view of the circuit breaker shown in Fig. 6, taken on the line VII- VU of Fig. 6, the electromagnetic latch means being omitted in order to simplify the -fgure;
  • Fig. 8 is a schematic diagram illustrating a In the present invention, however, there is provided .in cooperative association with the breaker a novel means for preventing reclosing of the contacts of the breaker during the existence of the .condition causing the overload.
  • the single-pole double-break circuit breaker illustrated comprises in general a recessed base 9, a pair ofA spaced stationary contacts I'I, a. pair of cooperating movable contacts I3, an actuating mechanism indicated generally at I5 which is operable in response to predetermined overload conditions to move the contacts I3 to open circuit position, and which is automatically operable after a predetermined time to return the movable contacts I3 to closed circuit position, and a means indicated generally at I1 for preventing reclosing of the contacts during the existence of the condition causing the overload.
  • the various parts of the circuit breaker are supported and enclosed by the base 9, which is of molded insulating material, and if desired, a cover I9, also of'molded insulating material, may be provided for closing the open side ofthe base.
  • the two movable contacts I3 are c arried by a switch member consisting of a pair of U-Shaped bimetallic control elements 21.
  • Each of the bi metallic control elements 21 comprises a substantially ilat strip of bimetallic material which- -ments 21.
  • the ends of the control ,elements opposite tothe ends whereon the contacts lI3 are supported are electrically and mechanically connected by means of a tie member 3 I which comprises a fiat strip of conducting material riveted to the ends ofthe elements 21.
  • a The interconnected control elements 21 are pivotally supported upon two spaced upstanding members 33 of insulating material, each of which is provided with a suitable bearing portion for engaging one of the pivot pins 29 of the control elements 21.
  • the support members 33 are secured to the base by means of suitable screws 3l.
  • the bimetallic control elements 21 constitute a part of the actuating means of the circuit breaker which will now be described. 4In addition to the bimetallic control elements 21, the actuating means of the breaker includes a U-shaped pivot actuating member 31 and a pair of overcenter springs 39 which connect the free end of the actuating member 31 to the tie member- 3I"of the bimetallic control elements.
  • the actuating member'31 is substantially U-shaped and ispivotally supported on a U-shaped support 4I secured to the base by means of screws 43.
  • the pivot ends of the actuating member 31 are provided with bearing portions 45 (Fig. 4) for envsprings 39.'
  • the tie member 3i and the cross portion 49 of the actuating member 31 are provided with openings which are engaged by the'bent ends of the overcenter springs 39.
  • a bracket member 5I which is fastened to the base 9 by suitable means, is provided for defining the limits of motion of the actuatingmember 31,' these limits being adjustable by means of set screws 53 and 55.
  • the limit of motion of the switch member consisting of the control elements 21 in a counter-clockwise direction about their pivot pins 29 is defined by the engagement'of the moving contacts I3 with the stationary contacts II, and the movement of the switch member in a clockwise direction is dened bythe engagement of the upper side of the contact end of each of the bimetallic elements 21 with a projection 51 that extends inwardly from the end wall ⁇ of the base 9.
  • the bimetallic -control elements ,21 are heated suillciently to move the tie member 3
  • the actuating means automatically recloses the contacts in the following manner. 21 have cooled, these elements assume their normal condition shown in Fig. l causing the tie member 3
  • This means comprises in.
  • pivoted latch 59 of magnetic-material or at least having a portion of magnetic material to form an armature, an electromagnet 6
  • the latch 59 is pivotally supported by means of a pivot pin 65 projecting from the side wall of the base 9 and is biased to an inoperative released position by means of a coiled compression spring 61 a portion of which extends within a bore provided -in the core of the electromagnet 6
  • a coiled compression spring 61 a portion of which extends within a bore provided -in the core of the electromagnet 6
  • One end of the spring engages a projection provided on the latch 59, while the other endof the spring engages an adjusting screw-69 which serves as an adjusting means for adjusting the amount of current required to move the latch from released to latching position.
  • comprises a core 1
  • the electromagnet is supported by an angle bracket 15 of magnetic material which is secured to one of the side walls of the base 9.
  • the horizontal portion11 of the bracket 15 serves to support a pair of spaced contacts 19 and 8
  • are adapted to be bridged to complete a circuit for the winding 13 of the electromagnet 6
  • the transformer 63 is mounted on the ba'se 9 on any suitable location, and comprises a core 89, a primary winding 9
  • , 85 and the transformer 63 are illustrated in the schematic diagram shown in Fig. 5.
  • of the transformer 63 ⁇ is connected in shunt relation across the contacts of the breaker by means of conductors 95 and 91, one terminal of the winding 9
  • One terminal of the secondary winding 93 of the transformer 63 is connected to one-end of the winding of the electrovmagnet 6
  • Theoperation of the means for preventing reclosing of the contacts of the breaker is brieiiy circuit" position.
  • is now energized an amount depending upon the impedance of the load since it is in series therewith. If the impedance of the load is below a predetermined amount, that is to say,
  • the electromagnet 6i is energized a sufficientamount by the current flowing through its winding to move the latch from its inoperative or released position, as shown in Fig. 2, to latched position, as shown in Fig.3, in which it engages the tie member 3
  • the circuit breakerA cannot be reclosedby the actua-ting mechanism until the impedance of the load is increased as by reducing the magnitude vof the load to a value substantially equal to or less than a safe normal full load value, or until the fault condition causing the overload is corrected or cleared.
  • V When this is done, the pull of the electromagnet 6
  • the adjusting screw 69 forms a simple adjusting means: for adjusting the amount of current required to cause the electromagnet to move the latch from inoperative to latching positiomso that the lock-out means
  • is so designed that the latch I9 'will be moved to its in any number of ways, one way being to have a very small air gap between the armature portion of the'latch 59 and the core 1I of the' electromagnet.'
  • vA modification-of the invention is illustrated in' Figs. 6 and 7.
  • the structure of the circuit breaker in this modiiication is substantially similar to the previously described circuit breaker and to the embodiment shown and described in connection with-Figs. 8 and 11 'of the aforementioned Patent No. 2,070,305.
  • the circuit breaker ' is provided with a manual operating means for opening and closing the breaker. Since the basic structure is substantially similar to the device previously described, the same reference characters will be lused wherever applicable.
  • the circuit breaker illustrated in Figs. 6 and '1 comprises in general a recessed base 9 of molded insulating material, a pair of stationary contacts II, a pair of cooperating movable contacts I3, an
  • a switch member consisting oi a pair of U-shaped bimetallic control elements 21, the upper ends of which are mechanically and electrically connected together by means of a tie member 3
  • the control elements 21 are provided with pivot pins 29 for) pivotally mounting the elements on a pair of spaced supporting members ⁇ 33 of insulating material.
  • the bimetallic control elements 21 form a part of the actuating means which will now be brieily described.
  • the actuati'ng'means for the breaker includes the bimetallic control elements 21, a U- shaped actuating member 31 pivoted at 41 on a support 4
  • is provided for deiining the limits of movement ofthe actuating member 31,'these'limits being adjustable by means of set screws 53 and 55.
  • the means I1 for preventing reclosure of the circuit breakery is identical to the correspondingV means of the previously described device, andV comprises generally a pivoted magnetic latch 59 l biased to released or inoperative position by a spring 81, an electromagnet ⁇ 6
  • is provided with an adjusting screw 69 which serves asan adjusting means for determining tire amount of vcurrent required to move the latch from inoperative to latched'position.Y
  • a pair of stationary contacts 19 and gl are' supported by and closing the contacts of the breaker.
  • Vthe bracket which supports the electromagnet 6
  • are adapted to be bridged by a bridging plate 85 of conducting material which is secured to the tie member 3
  • the circuit breaker is provided with a manual means indicated generally at
  • 09 comprises in general a bifurcated operating member III which straddles the actuating mechanism and which is pivotally vsupported by means'of pivot pins
  • 5 projects through an opening I2 I provided therefor in the cover
  • the actuating member 31 of the actuating means of the circuit breaker is provided with a Y- shaped coupling member
  • 21 is disposed between the depending projections II1 and II8 'of the operating member III for engagement thereby when the operating handle II-5 is moved.
  • 1 and IIB is such that they-permit the actuating member 31 to be movedY independently of the operating handle during automatic operation of the actuating means when the handle is in closed circuitv ber III of insulating material which extends 'I Athrough a slotted opening
  • This member Ill permits the latching member
  • 33 is biased by a spring I (Fig.y '7) towards latching position so as to latch the operating member II I when the same is moved to clo'sedcircult -V position.
  • the circuit breaker is -shown in the closed circuit position in Fig. 6. It will be noted that the latch
  • 8 is such as to permit automatic operation' of the actuating means I5 ⁇ when the handle is held latched in closed position.
  • the automatic operation ofv the actuating means is identical to the automatic operation of' the device shown in'Figs. 1 to 4 and previously described in connection therewith. Briey,' when the breaker is in closed position, the handle being held latched inclosed position, as shown in Fig. 6, and a predeterminedv overload or increase in temperature of the ambient medium occurs, the bimetallic control elements 21 expand in such a manner thatthe tie member 3
  • the immediate result is to .cause the actuating member 31 to move in a counter-clockwise direction, the limit of motion being deilned by the engagement of the upper end
  • the line ot action of the springs 39 iscarried vacross and above the pivot axis 29 ofthe connected bimetallic control elements, thereby causing those elements and the movable contacts I3 carried thereby to be moved from closed to open circuit position with a snap action.
  • 21, comprise in effect alost-motion connection between the operating handle and the actuating means.
  • 'I'he latch controlling electromagnet 6I and the transformer 63 are electrically connected in the i same manner asin the embodiment shown in Figs. :1 through 5 and described in connection therewith.
  • Theprimary of thev transformer 63 is connected in shunt relation to the main contacts of the breaker, and the secondary winding of the transformer yis connected lin series circuit With the electromagnet 6
  • the operation of the lock-out means indicated generally at I1 is substantially'identical with the corresponding means described in connection with Figs. 1 through 5.
  • the transformer 93 becomes energized when'the breaker opens, ,and the electromagnet 6
  • 41 which opens the circuit to the primary of the transformer when the operating handle is moved to open position to open the breaker.
  • 49 of the cut-out switch is moved downwardly to open the ⁇ switch by a projection ISI formed at the lower end oi' one of the legs of the operating member This projection III moves the plunger
  • 41 are adapted to be'connected in the conductor leading to the primary 9
  • FIG. 8 A further modification of the invention vis illus-V trated schematically in Fig. 8.
  • the circuit breaker' and ltsactuating means are identical' to that shown and described in connection with Figs. 1 through 4.
  • the breaker operates automatically in the same manner as.
  • Figs. 1 through 4 connect the electromagnet 6
  • the invention provides an improved automatically reclosing circuit breaker embodying a lnovel means for preventing reclosing of the contacts of 'thebreaker during theexistenc'e of the condition causing the overload, the means for preventing reclosing of the contacts being automatically rendered inoperative to prevent reclosure when the fault condition is cleared.
  • Iclaimasmy invention f, l..
  • actuating means including an overcenter spring for opening and closing said contacts and an electro-responsive element operable in response to predetermined overload conditionsfto cause' said spring to automaticallyv open said Lcontacts and operable to cause said spring vto automatically reclose said lcontacts following automatic opening thereof,
  • said means operable upon automatic openingof said contacts for preventing reclosing of said contacts during the existence of the condition causing the overload, said means comprising a latch normally biased to released position and movable to a latchlng position to hold said contacts open,
  • an electromagnet for moving said latch to latching position when -energized a predetermined amount, transformer the primary of which is connected in shunt relation tosaid contacts and -the secondary ⁇ of.which is conriected in series with said electromagnet, and means forfautomatlcally connecting said transformer secondary and said electromagnet in shunt relationto the load when said contacts are automatically opened, the magnetic circuit of said electromagnet being such that its reluctance is changed only a rela- )tively small ⁇ amount by the movement .of said Y latch to latching positioh so as to permitv return of said latch to released position when the currentilowing through said electromagnet is decreased to a value only 'slightly below the value required to cause said latch to be moved to latching position.
  • a circuit interrupter for controlling a load circuit, relatively movable contacts, an overcenter spring for opening and closing said contacts, an electro-responsive control element voperable in response to predetermined conditions to cause said spring to automatically open said contacts and for causing said spring to automatically reclose said contacts after ,an interval of time following said automatic opening operation, means operable upon automatic opening of said contacts for preventing reclosing of said contacts until the predetermined conditions haveceased l to exist, said means comprising a latch operable to latch said contacts open, and an electromagnet acting directly on said latch for controlling the latch, means electrically connecting said electromagnet in shunt relation to the load circuit when said contacts are automatically opened, and an impedance connected in shunt relation to said contacts, said electromagnet causing said latch to release said contacts for closing immediately upon cessation of said predetermined conditions. 4
  • a circuit interrupter for controlling a load circuit, relatively ⁇ movable contacts, an overcenter spring forlopening and closing said contacts, an electro-responsive control element operable inresponse to predetermined conditions to cause said 8911113 to automatically open said contacts and for causing said spring to automatically re- I close said contacts after aninterval of time ioling its secondary connected in circuit'l with the lowing said automatic opening operation, means operable upon automatic opening of said contacts for preventing reclosing of said contacts during the existence of said predetermined conditions, said meanscomprising a latch yoperable to latch said contacts open, an electromagnet acting directly on said latch for'controlling said latch, means for automatically electrically connecting said electromagnet in shunt with the load upon automatic opening of said contacts, and an impedance connected in circuit with the load upon automatic opening of said contacts, said electrovat magnet causing said latch to free said contacts for closing immediately upon cessation of said predetermined conditions.
  • actuating means including an overcenter spring for opening and closing said contacts and an electro-responsive control element operable in response to predetermined overload conditions to' cause said spring to automatically open said contacts and for causing said spring to automatically reclose lsaid contacts after a time interval following said automatic opening operation, means operable upon automatic opening of said contacts for preventing reclosing of said contacts if the impedof the conditions causing the overload.
  • actuating means including an overcenter spring for opening and closing said contacts and an electro-responsive control element operable in responsetofpredetermined overload conditions to cause said .spring to automatically open said contacts and for causing said spring to automatically reclose said contacts after a.
  • means operable upon automatic opening of said contacts for preventing reclosing of said contacts if the impedance ofthe load circuit is below a predetermined value, -said means comprising a latch operable tolatch said contacts open, an electromagnet for controlling said latch,'and a transformer the secondary of which is connected in circuit with said electromagnet and together with the electromag' net in shunt to the load upon automatic opening of saidcontacts, the primary'of said transformer being connected in'shunt to the contacts.
  • a circuit interrupter for controlling a load circuit, relatively movable contacts, an overcenter spring for opening and closingr lSaid. contacts.- an electro-responsive control element'operable in response to predetermined conditions to cause said lspring to automatically open said con- Y tacts and for causing said spring to automatically exist, said means comprising a latch operable reclose ,said contacts after an interval of time following said automatic opening operation.
  • circuit breaker forcontrolling a load circuit, relatively movable contacts, actuating means including an overcenter spring for opening and closing said contacts, and an electro- 10 responsive control element operable in response to predetermined overloadl conditions to cause said spring to automatically open said contacts, and -for4 causing said spring.
  • means operable upon automatic opening of said contacts for preventing reclosing of said contacts during the existence of the condition vcausing thegoverload said means comprising a latch operable to 20 latch said contacts open, an electromagnet acting directly on said latch for controlling said latch, means for automatically connecting said electromagnet in shunt ⁇ re1ation to the load when the contacts are automatically opened, andan 26 impedance connected in shunt relation to said contacts, said electromagnet being operable to cause said latch to release said contacts for reclosing immediately upon cessation of the condition causing said overload.
  • actuating means including an overcenter spring for opening and closing said contacts and an electro-responsive element operable in response to predeter- 3/5, mined overload conditions to cause said spring to l' automatically open said contacts and operable to cause said spring to automatically reclose said contacts following automatic opening thereof, meansV operable upon automatic opening of said 40 contacts for preventing reclosing ofsaid contacts during the existence of the condition caus ing the overload, said means comprising a latch.
  • an electromagnet for moving said latch to latching position when energized a predetermined amount
  • a transformer the primary of which is connected in shunt relation to said contacts and the secondary of which is connected in series with said electromagnet
  • actuating means automatically operablein response to predetermined conditions to open said l contacts and tothereafter reclose said contacts, a manual operating handle' movable to cause 70 opening or closing of said contacts, an impedc ance connected at all times in shunt relation to said oontactarmeans operable upon automatic opening of said contacts for preventing reclosing of said contacts as long as said predetermined condition exists, and means operable by opening movement o! the manual operating handle for opening the circuit to interrupt the flow of cur- 10.
  • a circuit breaker for controlling a load circuit eomprising relatively movable contacts, actuating means including an overcenter spring for opening and closing said contacts, an electro-responsive element operable to cause said spring to automatically open said contacts, in response to predetermined overload conditions and for causing v'said spring to automatically reclose said contacts after automatic opening thereof, a manually operable handle operable to open and to close said contacts, an impedance connected in shunt to said contacts, and electromagnetic means operable upon .automatic opening of said contacts to prevent reclosing of said contacts as long as the impedance of Athe load circuit is below a predetermined value, and anadditional pair of contacts in the circuit opened by opening movement ⁇ of said manual operating handle for interrupting l0 the flow of current in the circuit.

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US163212A 1937-09-10 1937-09-10 Circuit breaker Expired - Lifetime US2215792A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US163212A US2215792A (en) 1937-09-10 1937-09-10 Circuit breaker
DES133782D DE721791C (de) 1937-09-10 1938-09-08 Selbsttaetige elektrische Schalteinrichtung

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US163212A US2215792A (en) 1937-09-10 1937-09-10 Circuit breaker

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US2215792A true US2215792A (en) 1940-09-24

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US163212A Expired - Lifetime US2215792A (en) 1937-09-10 1937-09-10 Circuit breaker

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DE (1) DE721791C (de)

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DE721791C (de) 1942-06-18

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