US3550049A - Current limiting circuit breaker with electrodynamic compensation - Google Patents

Current limiting circuit breaker with electrodynamic compensation Download PDF

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Publication number
US3550049A
US3550049A US833922A US3550049DA US3550049A US 3550049 A US3550049 A US 3550049A US 833922 A US833922 A US 833922A US 3550049D A US3550049D A US 3550049DA US 3550049 A US3550049 A US 3550049A
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US
United States
Prior art keywords
contacts
circuit breaker
contact
electrodynamic
arm
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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
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US833922A
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English (en)
Inventor
Guy Blanc-Tailleur
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.)
Merlin Gerin SA
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Merlin Gerin SA
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Publication date
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    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H77/00—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting
    • H01H77/02—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism
    • H01H77/10—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism with electrodynamic opening
    • H01H77/101—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism with electrodynamic opening with increasing of contact pressure by electrodynamic forces before opening

Definitions

  • This automatic opening of the contacts is reversible until the tripping device of the circuit breaker, which is generally an electromagnetic tripping device but which may also be an electrodynamic tripping device, gives a positive order for the opening of all the poles of the apparatus, unlocking the movable contacts.
  • This control order is given as a function of the instantaneous value of the current when the latter increases above a predetermined value, regardless of the relative position of the contacts which have been separated by the said electrodynamic forces.
  • the repulsion action of the contacts is practically instantaneous but the unlocking which results from the action of the tripping device is delayed by the intervention of inertia, hysteresis phenomena, etc.
  • Precious milliseconds elapse between the start of the automatic electrodynamic opening of the contacts against the contact springs and the actual unlocking of the movable contacts.
  • the automatic opening of the contacts may be hesitant, in particular when the overcurrent is close to the limit value which causes said automatic opening, or when the substantial current decreases in its cycle (or alternation). Weldings and wear of the contacts then occur, making the apparatus unusable sooner or later.
  • French Pat. 1,316,904 shows such a device in which a dividing of the main contacts makes it possible to divide the current passing through the closed contacts into two parallel branches so as to produce an electrodynamic force which tends to increase the pressure of the closed contacts against the opposing force of repulsion which leads to the automatic opening.
  • the movable contact executes a swinging movement to open a pair of main contacts to close the arcing contacts and then to open the other pair of main contacts, thus destroying the compensation as a result of the geometric configuration of the conductive parts in question.
  • the swinging movement of the movable contact is caused by a special electromagnetic or electrodynamic tripping device which intervenes in the mechanical control of the movable contact, resulting in a delayed action which makes the automatic opening problematical.
  • the flexible conductor for the feeding of the current to the movable contacts always acts in the sense of destroying the compensation, thus also making the compensation problematical, even in the closed position of the two pairs of main contacts.
  • An object of the present invention is an improvement in circuit breakers allowing a definite instantaneous automatic transition from the compensated state to the automatic-opening state without the use of special tripping devices and without recourse to subdividing of the main contacts.
  • Still another object of the invention is a circuit breaker in which the contacts are electrodynamically compensated until the very moment of their separation, from which moment on the electrodynamic forces cause the rapid opening of the contacts.
  • FIG. 1 is a schematic side view illustrating the principle of a known contact device with electrodynamic compensation, the device being shown in its normal closed circuit position;
  • FIG. 2 shows the same device at the start of its opening stroke under the action of the electrodynamic forces
  • FIG. 3 shows the device of FIGS. 1 and 2 after the intervention of the tripping device
  • FIG. 4 shows schematically, in side view, a contact device according to the invention in its normal closed circuit position
  • FIG. 5 shows this device of the invention as it is just about to unlock
  • FIG. 6 shows the device of FIGS. 4 and 5 just after unlocking at the time when the arcing contacts touch each other and then immediately separate in order to establish an arc
  • FIG. 7 shows this device at the end of the opening stroke caused by the electrodynamic forces
  • FIG. 8 shows this device at the end of the opening stroke after the actuation of the tripping device (not shown);
  • FIGS. 9, 10, l1, l2 and 13 shows, in side view and partially in section, a practical embodiment of a compensated limiting circuit breaker according to the invention, these figures corresponding to FIGS. 4, 5, 6, 7 and 8 respectively.
  • FIGS. 14 to 17 show schematically in side view the principle of another embodiment, the different posi tions corresponding to those of FIGS. 4, .5, 6 and 7 respectively.
  • a movable contact supporting arm 10 is connected by its end 12 to a connection bar 14 by means of a flexible conductor or strap 16 arranged in the form of a loop.
  • the upper portion of the arm 10 bears a main contact stud 18 and towards the top an arcing contact stud 20, which contact studs cooperate with the main stationary contact stud 22 and the arcing contact stud 24 respectively which are disposed on a stationary contact support member 25 which is connected to the other connecting bar 26.
  • the arm 10 is pivotally mounted by means of a lug 27 on a pin 28 borne by a support member 30 which in its turn is pivoted on a fixed pin 32.
  • the pin 28 is arranged between the end 12 and the upper part of the contact arm 10 and a compression spring 33 which brings the contacts together acts on the end 12, its other end resting against a stationary surface 35.
  • the opening and closing of the contacts is effected by a rotary drive shaft 34, one crank 36 of which is pivoted at 37 on an insulating connecting rod 38, the other end of which is articulated at 39 to an arm 40 which is rigidly connected with the support 30.
  • the opening of the contacts takes place by rotation of the drive shaft 34 in anti-clockwise direction which is caused by a tripping device (not shown) which permits the displacement of the pins 37, 39 and 28 and thereby unlocks the support 30.
  • a tripping device (not shown) which permits the displacement of the pins 37, 39 and 28 and thereby unlocks the support 30.
  • the pin 28 moves, liberating the arm 10 which then pivots around the main contact 22 until the arcing contacts 20, 24 touch (see FIG. 2) and the main contacts are subsequently separated.
  • the compensation effect is destroyed by the spatial position of the arcing contacts and the arm 10 is then suddenly pushed back towards the open circuit position shown in FIG. 3.
  • FIGS. 4 to 13 which illustrate a first embodiment of the invention
  • the electrical circuit of the pole is identical to that of FIGS. 1 to 3, as is the mounting of the contact arm 10 by a pin 28 on a support 30- which is articulated at 32.
  • the support 30 has an arm 46 the end of which cooperates with a locking device consisting in the example selected of two rollers 48 and 50 cooperating with a stop 52 which is integral with the arm 46.
  • the roller 48 is borne by the end of said arm 46 and the roller 50 by the end of a lever 54 which is pivoted at 39 to the end of the operating rod 38.
  • a knuckle joint comprising two toggle levers 60', 62 pivoted at 58, the opposite ends of which are pivoted at 39 and 32 respectively.
  • An elastic biasing force produced by compression spring 64 which rests at its ends against a lug 66 of the lever 62 and against the lever 60 respectively, tends to stretch the knuckle joint.
  • a trip rod 70 which is rigidly connected with the locking lever 54 is arranged opposite and a small distance from the element 66 of the lever 62 so that upon a bending of the knuckle joint 58 having levers 60, 62, against the action of the spring 64, it comes against and is acted upon by the element 66, causing the releasing of the locking device 50, 48 by pivoting in anticlockwise directions of the lever 54 around the pin 39 and therefore the unlocking of the support 30 and the release of the pole.
  • a slot 72 in the lever 54 limits the swinging movement of the locking lever 54 in both directions with respect to the pin 58 which passes through it.
  • the contact device of FIGS. 4 to 8 and 9 to 13 respectively operates as follows:
  • the element 66 of the knuckle joint pushes the trip rod 70 and releases the roller 48 from the roller 50 (see FIGS. 6 and 11).
  • the support 30 is then entirely free and swings, the opening of the circuit breaker taking place by the coming into contact with each other of the arcing contacts 20, 24, followed by the separation of the main contacts 18, 22 with rupture of the electrodynamic compensation and by rapid separation of the arcing contacts (see FIGS. 7 and 12).
  • This opening is obtained in powerful manner as a result of the electrodynamic forces of repulsion between the contacts, the compensation being now entirely de stroyed, and also as a result of the contact pressure spring 33, since the pin 28 has been freed.
  • the roller 28 of the pin 28 comes against the part 71 and the arm 10 comes against the stop 31.
  • the locking lever 54 which is stopped by the striking of the left end of the slot 72 against the pin 28 can cause at the end of its stroke the tripping of the conventional automatic opening mechanism (consisting of a tripping device not shown) of all the poles, causing the rotation of the drive shaft 34 in suitable manner. This results in a displacement of the opening rod 38 which returns the lever 54 into reset position by means of the spring 74, ready for another operation (see FIGS. 8 and 13).
  • the locking lever 54, arm 46 and knuckle joint 60, 62 constitute practically a rigid assembly which brings the contact arm 10 into closed position.
  • FIGS. 14 to 17 Another embodiment of the invention is illustrated in FIGS. 14 to 17 in which again the pole comprises the support 30 as well as the drive or control shaft 34.
  • the pole comprises the support 30 as well as the drive or control shaft 34.
  • connecting rod 38 of FIGS. 4 to 8 is connected to the pin 39 by an interlock mechanism which comprises a hollow housing 76 rigidly connected with the connecting rod 38 and having a step at 78 leading to a cavity 80.
  • a spring :82 is guided so that it is contained along the extension of a rod 84 which is pivoted at 39.
  • a guide cage 86 of the spring 82 has an inclined plane 88 which cooperates with a stop 90.
  • the compression spring 82 rests against the rod 84, on the one end, and against a lock 92, on the other end. In closed circuit position (see FIG. 14), the lock 92 rests against the step 78.
  • FIGS. 14 to 17 are similar to that of FIGS. 4 to 13.
  • the tripping of the other poles which have not been automatically tripped individually is brought about by the pivoting of the connecting rod 36 in anti-clockwise direction and resets the lock 92 in front of its step 78 after having effected a certain compression of the spring 82 which was relaxed during the tripping due to the lefthand wall of the housing 76 which rests against the lefthand end of the spring 82.
  • a circuit breaker comprising an elongated movable contact arm, a movable contact member mounted on a first end portion of said contact arm and cooperating with a relatively stationary contact member, conducting current supply means connected to a second end portion of said contact arm, said conducting means forming part of a current loop, said contact members in their normal closed circuit position being urged together by electrodynamic forces due to currents flowing in said loop, a movable support member for said contact arm, bias means for elastically biasing said support member towards its normal closed circuit position, releasable locking means to confine the movement of said support member between its said normal closed circuit position and a predetermined intermediate position in opening direction, and control means to release said locking means and adapted to be operated by said support member substantially in its said intermediate position to cause the unlocking of said support member and the opening of said circuit breaker, whereby said electrodynamic forces urge said contact arm towards its open circuit position after unlocking of said support member.
  • a circuit breaker according to claim 1 wherein said support member is pivotably mounted on a fixed axis.
  • bias means comprise spring means, said control means comprising abutment means abutting upon a predetermined straining of said spring means.
  • control means comprise a toggle lever stressed by said spring means.
  • a circuit breaker according to claim 2 wherein said contact members comprise a pair of main contacts and a pair of arcing contacts, said contact arm executing a swinging movement between upon unlocking of said support member to sequentially close said arcing contacts, open said main contacts and open said arcing contacts.
  • a circuit breaker according to claim 8 wherein said main and arcing contacts are disposed in position so that said electrodynamic forces urge said main contacts together until unlocking of said support member.
  • a circuit breaker comprising a pivotably mounted contact arm, a movable main and a movable arcing contact disposed on said contact arm and cooperating respectively with a relatively stationary main and a relatively stationary arcing contact, conducting means to supply current to said movable main and arcing contacts, said movable and relatively stationary main contacts being urged together in their normal closed circuit position by electrodynamic forces due to currents flowing in said conducting means, releasable locking means limiting the pivotal movement of said contact arm between its normal closed circuit position and a position intermediate between said normal closed circuit position and an open circuit position, spring means biasing said contact arm towards said normal closed circuit position, and control means operable by said contact arm to release said locking means and unlock said contact arm in said intermediate position causing the momentary closing of said arcing contacts and the opening of said circuit breaker, the opening movement of said contact arm being accelerated by said electrodynamic forces.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Breakers (AREA)
  • Driving Mechanisms And Operating Circuits Of Arc-Extinguishing High-Tension Switches (AREA)
US833922A 1968-07-05 1969-06-17 Current limiting circuit breaker with electrodynamic compensation Expired - Lifetime US3550049A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR158223 1968-07-05

Publications (1)

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US3550049A true US3550049A (en) 1970-12-22

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US833922A Expired - Lifetime US3550049A (en) 1968-07-05 1969-06-17 Current limiting circuit breaker with electrodynamic compensation

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US (1) US3550049A (ja)
BE (1) BE734825A (ja)
CH (1) CH493929A (ja)
DE (1) DE1933576C2 (ja)
ES (1) ES368585A1 (ja)
FR (1) FR1580422A (ja)
GB (1) GB1222456A (ja)
NL (1) NL163049C (ja)
SE (1) SE358506B (ja)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3737821A (en) * 1970-09-25 1973-06-05 Cableform Ltd Electrical contactors
US3921109A (en) * 1974-06-20 1975-11-18 Westinghouse Electric Corp Circuit-interrupter
US4550299A (en) * 1983-07-04 1985-10-29 Asea Aktiebolag Electric switch with protective function
DE3432086A1 (de) * 1984-08-28 1986-03-06 Siemens AG, 1000 Berlin und 8000 München Kontaktanordnung mit einer die kontaktkraft vergroessernden stromabhaengigen kraft
DE3604784A1 (de) * 1986-02-13 1987-08-20 Siemens Ag Verfahren und vorrichtung zur herstellung von abschnitten einer metallfolie
US4827233A (en) * 1987-04-02 1989-05-02 Texas Instruments Incorporated Miniature circuit breaker with improved longivity
US5189384A (en) * 1991-11-06 1993-02-23 Westinghouse Electric Corp. Circuit breaker having improved contact structure
US6140894A (en) * 1996-07-05 2000-10-31 Fki Plc Electrical circuit breakers
CN101533744B (zh) * 2008-09-26 2011-02-02 厦门宏美电子有限公司 一种塑壳限流断路器动触头斥开后防跌落机构

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL173577C (nl) * 1979-05-21 1984-02-01 Hazemeijer Bv Stroombegrenzende snelwerkende schakelaar.
GB8519740D0 (en) * 1985-08-06 1985-09-11 Ashley Accessories Ltd Mains electrical accessories
US4656444A (en) * 1985-08-16 1987-04-07 Westinghouse Electric Corp. Circuit breaker with force generating shunt
DE3604782A1 (de) * 1986-02-13 1987-08-20 Siemens Ag Vorrichtung zum pressschweissen paketierter metallfolien
DE19740422B4 (de) * 1997-09-10 2005-10-06 Siemens Ag Strombegrenzender Niederspannungs-Leistungsschalter

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE262424C (ja) *
US2839632A (en) * 1954-11-18 1958-06-17 Comp Generale Electricite Circuit breaker
GB942916A (en) * 1961-07-13 1963-11-27 Comp Generale Electricite An improved circuit-breaker for alternating currents
US3238339A (en) * 1961-03-13 1966-03-01 Licentia Gmbh Heavy duty switch held in closed position by parallel current branches and assisted in movement to open position by antiparallel branches

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1107330B (de) * 1958-08-13 1961-05-25 Calor Emag Elektrizitaets Ag Elektrischer Schalter zur selbsttaetigen Unterbrechung von UEber- und Kurzschlussstroemen
AT232575B (de) * 1959-12-07 1964-03-25 Licentia Gmbh Leistungsschalter
DE1127453B (de) * 1960-03-24 1962-04-12 Elektro App Werke J W Stalin V Elektrodynamisches System zur Betaetigung der Schaltkontakte eines elektrischen Schalters, insbesondere eines Leistungsschalters
NL259252A (ja) * 1960-12-21
FR1316904A (fr) * 1961-03-13 1963-02-01 Licentia Gmbh Système de contacts pour interrupteurs électriques de puissance

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE262424C (ja) *
US2839632A (en) * 1954-11-18 1958-06-17 Comp Generale Electricite Circuit breaker
US3238339A (en) * 1961-03-13 1966-03-01 Licentia Gmbh Heavy duty switch held in closed position by parallel current branches and assisted in movement to open position by antiparallel branches
GB942916A (en) * 1961-07-13 1963-11-27 Comp Generale Electricite An improved circuit-breaker for alternating currents

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3737821A (en) * 1970-09-25 1973-06-05 Cableform Ltd Electrical contactors
US3921109A (en) * 1974-06-20 1975-11-18 Westinghouse Electric Corp Circuit-interrupter
US4550299A (en) * 1983-07-04 1985-10-29 Asea Aktiebolag Electric switch with protective function
DE3432086A1 (de) * 1984-08-28 1986-03-06 Siemens AG, 1000 Berlin und 8000 München Kontaktanordnung mit einer die kontaktkraft vergroessernden stromabhaengigen kraft
US4636762A (en) * 1984-08-28 1987-01-13 Siemens Aktiengesellschaft Contact assembly having a current-dependent force increasing the contact force
DE3604784A1 (de) * 1986-02-13 1987-08-20 Siemens Ag Verfahren und vorrichtung zur herstellung von abschnitten einer metallfolie
US4827233A (en) * 1987-04-02 1989-05-02 Texas Instruments Incorporated Miniature circuit breaker with improved longivity
US5189384A (en) * 1991-11-06 1993-02-23 Westinghouse Electric Corp. Circuit breaker having improved contact structure
US6140894A (en) * 1996-07-05 2000-10-31 Fki Plc Electrical circuit breakers
CN101533744B (zh) * 2008-09-26 2011-02-02 厦门宏美电子有限公司 一种塑壳限流断路器动触头斥开后防跌落机构

Also Published As

Publication number Publication date
NL163049C (nl) 1980-07-15
CH493929A (fr) 1970-07-15
DE1933576A1 (de) 1970-03-05
NL163049B (nl) 1980-02-15
BE734825A (ja) 1969-12-01
GB1222456A (en) 1971-02-17
DE1933576C2 (de) 1982-01-14
FR1580422A (ja) 1969-09-05
SE358506B (ja) 1973-07-30
ES368585A1 (es) 1971-05-01
NL6909171A (ja) 1970-01-07

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