US3564178A - Circuit-breaker with pressure balanced relatively movable contacts - Google Patents

Circuit-breaker with pressure balanced relatively movable contacts Download PDF

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Publication number
US3564178A
US3564178A US719339A US3564178DA US3564178A US 3564178 A US3564178 A US 3564178A US 719339 A US719339 A US 719339A US 3564178D A US3564178D A US 3564178DA US 3564178 A US3564178 A US 3564178A
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United States
Prior art keywords
contacts
contact
circuit
breaker
chamber
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Expired - Lifetime
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US719339A
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English (en)
Inventor
Rintje Boersma
Gijsbert W Irik
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COQ NV
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COQ NV
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    • 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
    • H01H33/70—Switches with separate means for directing, obtaining, or increasing flow of arc-extinguishing fluid
    • H01H33/80—Switches with separate means for directing, obtaining, or increasing flow of arc-extinguishing fluid flow of arc-extinguishing fluid from a pressure source being controlled by a valve
    • H01H33/82—Switches with separate means for directing, obtaining, or increasing flow of arc-extinguishing fluid flow of arc-extinguishing fluid from a pressure source being controlled by a valve the fluid being air or gas

Definitions

  • a circuit-breaker is provided with relatively movable contacts and an actuating rod is attached to one of the contacts to effect separation of the contacts and opening of the circuit-breaker.
  • the contact assembly is housed within an outer chamber which is subjected to insulating gas under high pressure and the contact assembly forms an inner chamber which, when the contacts are closed, is isolated from the outer chamber and which is vented to a pressure lower than the pressure in the outer chamber.
  • a small net force acts on the movable contact to which the actuating rod is attached to maintain the contacts in closed condition.
  • the pressure differential existing between the outer and inner chambers is used in substantially balancing fashion and additional means is provided for cooperating with this differential pressure effect to establish the small net force serving to maintain the contacts in closed condition.
  • the pressure differential disappears and full pressure balance is effected so that both upon initial opening and continued opening movement as effected by the actuating rod, the actuating rod is subjected to very little mechanical stress.
  • the opening of the contacts opens a valve formed between separable contacts and communicating the inner chamber with the outer chamber and allowing the insulating or extinguishing gas to rush past the contacts and axially through at least one of them for extinguishing the are produced by opening of the contacts.
  • ATTORNEYS sum 1 ⁇ IF-12 DDK.
  • the invention relates to a gas blast circuit-breaker comprising a switching chamber filled with extinguishing gas under pressure and containing at least one pair cooperating contacts which are carried by fixed contact holders, at least one of said contacts having a central passage for the discharge of extinguishing gas during the opening operation and at least one of said contacts being a movable contact and forming together with its contact holder a cylinder-piston-system which is loaded by the extinguishing gas and by means of which said movable contact is driven in the opening direction by the extinguishing gas during the opening operation, said movable contact forming the movable part of a valve-system formed by said movable contact and the other contact or the holder thereof for keeping said switching chamber and said discharge passage separated from one another, when the circuit-breaker is in its closed position, and said movable contact being loaded during its closing movement by a readjusting force.
  • Gas blast circuit-breakers of this kind are mostly adapted to interrupt the electric circuit and to extinguish the switching arc only. in the condition of rest their cooperating contacts are in contact with each other, so that such circuit-breakers can only be u'sedwhen connected in series with an isolatorswitch for keeping the circuitinterrupted and for closing same.
  • These gas blast circuit-breakers have the advantage that the movable contact with all accessories is very light and has only to be moved over a small distance and that extinguishing gas of relatively high pressure is at once available to separate the contacts and to extinguish the switching arc.
  • these circuit-breakers have also some disadvantages.
  • the controlling of theisolator-switch connected in series therewith is not positively connected with the circumstances in the gas blast circuit-breaker, so that it can happen, that'when the circuit-breaker, after an opening command has been given, responds with hesitation to said command the isolator-switch opening independently of said fact the predetermined space of time after saidcommand is put in operation before the switching are set up in the circuitbreaker has been extinguished.
  • Another difficulty is that the position of the movable contact cannot be observed from the outside.
  • circuit-breakers for high tension provided with multiple interruption, consequently in circuit-breakers comprising a number of pairs of cooperating contacts connected in series, the disadvantage exists, that the movablejcontacts can move independently 'of one another, so that there is no certainty, that the interruption of the electric circuit will happen in all places of interruption at the same or substantially the same time.
  • the invention has for its object to provide a gas blast circuit-breaker of the'described kind which has the good points but not the mentioned disadvantages of the known circuitbreakers. It consists in that the cylinder-piston-system and the valve-system are so constructed and the readjusting force is so chosen as to produce in the closed conditionof the circuitbreaker a holding force to keep said movable contact and said valve-system in their closed positions and as to allow the extinguishing gas to drive the movable contact towards its open position immediately after the valve-system has been opened, said movable contact being connected by mechanical coupling means to anex'ternal auxiliary driving mechanism, by means of which said movable contact is moved, at least at the beginning of the opening operation, against said holding force and said valve-system is opened.
  • the extinguishing gas then acts only in the opening direction on the movable contact and said contact is driven with great speed in said direction by the great difference of pressure'which, at the beginning of the opening operation, is set up over the piston cooperating with said contact.
  • the readjusting force has only to be small in respect of the force exerted in the opening direction on the movable contact by the extinguishing gas and it may even be reduced to zero during the opening operation. Consequently, the auxiliary driving mechanism and the coupling means can be made for light duty, since they have to exert on the movable contact only a relatively small force in the opening direction at the beginning of the opening operation.
  • circuit-breakers differ principally from circuit-breakers provided with external driving mechanisms which have also to produce the very great force to accelerate the movable parts.
  • Such mechanisms must be strong and robust and made for heavy duty.
  • the force required to accelerate the movable contact is produced, as in the known gas blast circuit-breakers of this kind, almost exclusively by the pressure of the extinguishing gas exerted on the cylinderpiston-system of said contact.
  • the valve-system can be made, in such a manner, that it is kept in its closed position by the pressure of the extinguishing gas contained in the switching chamber, so that said valvesystem produces at least a part of the holding force.
  • the valvesystem then could be formed as a nonbalanced disc valve.
  • the readjusting force may be reduced to zero in the closed condition of the circuit-breaker and therefore be produced, if desired, by the auxiliary driving mechanism.
  • the valve-system may also be constructed, in such a manner, that it is balanced in its closed condition. In that case force the switching chamber.
  • the auxiliary driving mechanism can be constructed in a simple manner, say formed as a single acting cylinder-piston-system, which has only to open the valve-system to initiate the opening operation of the circuit-breaker.
  • gas blast circuit-breaker is meant for high voltages and for that reason is provided with at least two pairs of cooperat ing contacts connected in series, it is advantageous to interconnect corresponding movable contacts of said paris of contacts and to connect them to a common external auxiliary.
  • FIG. 1 is a vertical sectional view of a gas blast circuitbreaker according to the invention provided with two pairs of cooperating contacts connected in series;
  • FIG. 2 is a vertical sectional view of another gas blast circuit-breaker according to the invention provided with one pair of pooperating contacts, which are both movably mounted;
  • FIG. 3 is a vertical sectional view of a pair of contacts of still another gas blast circuit-breaker according to the invention, in which the movable contact cooperates with the holder of the fixed contact as a balanced slight-valve-system.
  • FIG. 1 is a metal vessel to be connected with earth. Contained in this vesselare three electrically conductive contactholders 2, 3 and 4, which are kept spaced from one another and fromthe vessel 1 by insulators 5, 6 7 and 8. The contactholders 2 and 4 are-connectedwith connecting conductors 9 and 10 for the connection of the circuit-breaker to the electric circuit to be interrupted.
  • the contact-holder 2 carries a fixed contact consisting of a circular series'of contact fingers 11. Cooperating with this fixed contact is an axially movable nozz'le contact 12 which is associated with a piston 14 mounted for reciprocation in a cylinder 13. This nozzle contact and said piston are mounted for sliding over a stationary tube 15 for the discharge'of extinguishing gas.
  • the discharge tube 15 is connected through a passage 16 formed in the contact-holder 3 to discharge tube composed of tubes 17, 18, 19 of insulting material and leading, for instance to a deionization-chamber I (not shown), in which the pressure increases during the opening operation.
  • the cylinder 13 and the discharge tube 15 are attached to the contact-holder 3.
  • a same pair of cooperating contacts 11, 12 with all accesseries is provided between the contact-holders 3 and 4.
  • the movable nozzle contacts 12, 12 are each provided with an annular valve-rim 20, 20', which cooperates with an annular seat 21, 21' carried by the contact-holder 2, 3.
  • This circuitbreaker is only meant to interrupt the electric circuit and to extinguish theswitching are, so that it is mounted in-the electric circuit in series with an isolating-switch (not shown).
  • the circuit-breaker is normallyclosed and the valve-rims 20, 20' are then forced against the seats 21, 21 so that the switching chamber 22 containing extinguishing gas under pressure. is separated from the discharge passages 15, 15', 16 16', 17, 18, 19.
  • the switching chamber 22 is supplied with extinguishing gas through the conduit 23.
  • the movable contacts 12, 12' are connected by rods 24, 25 of insulating material and a metal rod 26 with one another, with a piston 28, which is mounted for reciprocation in a cylinder 27 and is exposed to the pressure of the extinguishing gas to produce a readjusting force, and with an auxiliary driving mechanism which consists of a stationary piston 29 and a movable cylinder 30 connected with the rod 26by an arm 31.
  • the extinguishing gas contained in the switching chamber acts, in the closing direction, onthe piston 28 and on the annular surfaces bounded by the outer diameters of the valve-rims 20, 20' and the outer diameters of the nozzle contacts 12, 1 2" and, in the opening direction, on the annular surfaces bounded by the outer diameter of the pistons 14, 14' and the outer diameters of the nozzle contacts 12, 12'.
  • the force exerted by the extinguishing gas in the closing direction on the movable nozzle contacts 12, 12' isgreater thanthe force exerted in the opening direction on said contacts, so thatsaid contacts are kept in the closed position and the valve-systems 20, 21 and 20', 21 are kept closed by a holding force which is equal to the difference of the forces exerted by the extinguishing gas on the movable contacts and the piston 28'.
  • the holding force can have, at a given pressure of the extinguishing gas, the smallest allowable value, so that the auxiliary driving mechanism has only to overcome said minimum holding force to initiate the opening operation, that means to open the valve-systems 20, 21 and 20', 21'. if the proportions are selected well the auxiliary driving mechanism 29, 30 and the coupling rods 24, 25 can be made for light duty.
  • the contactholder 37 carries a second movable nozzle contact 42 which is provided for sliding movement on a discharge tube 43 andis attached to a cylinder-piston-system 44, 45 for its movement in the opening direction.
  • the nozzle contact 38 is provided with a circular series of contact fingers 46 which embrace the free end portion of the nozzle contact 42, when the circuitbreaker is in its closed conditionjln addition the nozzle contacts 42 and 38 form together a nonbalanced valve-system and to that end they are provided with a seat 47 and a valve-rim 48 cooperating with said seat.
  • the s'eatand the valve-rim 47, 48 separate, in the closed condition of the circuit-breaker, the switching chamber 49 containing extinguishing gas under pressure from a gas discharge conduit 50 which is in open communication with the dischargetubes 39 and 43.
  • the contacts 38 and 42 are loaded'by readjusting springs 51, 52 which drive the contacts towards each other, as soon as the pressure difference over the pistons 41, 45 has become sufficiently low after the circuit-breaker has reached its opened end position.
  • the nozzle contact 42 is connected by a coupling rod consisting of insulators 53, 54 and metal rods 55, 56 to an external auxiliary driving mechanism which consists of a stationary piston 57 and a movable cylinder 58 connected with the ro 56byanarm59.
  • the circuit-breaker of which only one pair of cooperating contacts is shown in FIG. 3, is provided with stationary contact holders 60, 61, each of which carries an extinguishing gas discharge tube 62, 63.
  • the contact-holder 60 also carries a fixed contact consisting of a circular series of contact fingers 64 and the contact-holder 61 is provided with an axially movable nozzle contact 65 cooperating with said fixed contact and internal cylindrical surface 68 formed on the movable nozzle contact 65 constituted together with an external cylindrical surface 69 of a ring member 70 carried by the contact-holder '60 and provided with a packing ring 71 a slide-valve-system for separating, in the closed position of the circuit-breaker, the switching chamber 72 containing gas under high pressure from the discharge tubes 62 and 63.
  • the specialty of this circuit-breaker is that the external diameter of the piston 67 is equal to the diameter of the cylindric surface 68, so that the slide-valve-system is balanced, when the circuit-breaker is in its closed position.
  • the readjusting force and the holding force are produced by a cylinder 73 and a piston 75 which ismounted on the coupling rod 74 and loaded by the extinguishing gas in the switching chamber 72.
  • a readjusting-holding-spring operating either on said coupling rod 74 or directly on the nozzle contact 65 may be used for that purpose.
  • the auxiliary driving mechanism to open the operation of the circuit-breaker is not shown. I
  • auxiliary driving mechanism for gas blast circuit-breakers of the present kind a mechanical, an electromagnetical, a pneumatic or an hydraulic driving mechanism or a combination of such mechanisms may be used.
  • the pressure in the discharge passages is at first quickly increased, so that the readjusting force'may be made very small.
  • this readjusting force may be permanently present and it may be produced by a readjusting piston loaded by the pressure prevailing in the switching chamber or be furnished by readjusting springs.
  • the auxiliary driving mechanism it is also possible to use the auxiliary driving mechanism to produce the readjusting force. Said mechanism must then be operated in the opposite direction. In thelatter case the readjusting force is reduced to zero during the open operation, so that it does not counteract said opening operation.
  • both the control of the isolator-switch connected in series with the circuit-breaker and used for the permanent interruption and the closing of the electric circuit and the indication of the position of the movable switching contacts can be easily derived from the position of the coupling rod.
  • the coupling rod acts also as a mechanical connection between the movable contacts of pairs'of cooperating contacts connected in series, having that during the opening operation therein, contacts are moved at the same time and in the same manner.
  • a gas blast circuit-breaker comprising a container having inner and outer compartments formed therein, the outer compartment being filled with extinguishing gas under pressure, at least one pair of cooperating contacts contained in the inner compartment, at least one of said contacts being a movable contact and at least one of said contacts having a central passage for the discharge of extinguishing gas during the opening operation of the circuit-breaker, said discharge passage being in open communication with said innercompartment, a piston attached to said movable contact andadapted to drive said movable contact in the opening direction, said piston having one side permanently exposed to the pressure of the gas contained in the outer compartment for urg'ing said movable contact in the opening direction, a valve surrounding said inner compartment and constituted by two cooperating valve members, of which one is fixed to one contact and the other one is fixed to the other contact of said pair of cooperating contacts, said valve being closed and separating the inner compartment and the discharge passage from the outer compartment when the circuit-breaker is in its closed condition, and said valve being opened directly after the opening operation of the circuit-breaker
  • a gas blast circuit-breaker according to claim 1 in which the force exerted on the valve by theextinguishing gas contained in the outer compartment, when the circuit-breaker is in its closed condition, is greater than the force exerted on the piston of the movable contact by said gas, the difference between said forces producing at least a part of the holding force.
  • a gas blast circuit-breaker in which the force exertedon the valve by the extinguishing gas contained in the outer compartment, when the circuit-breaker is in its closed condition, is equal to the force exerted on the piston of the movable contact by said gas and in which a second piston is provided, said second piston being also coupled with the movable contact and having its side for the closing action on said contact permanently exposed to the pressure of the gas contained in the outer compartment, the holding force being produced by said second piston.
  • a gas blast circuit-breaker as claimed in claim 1 in which at least two pairs of cooperating contacts are electrically connected in series, corresponding movable contacts of said pairs of contacts being connected by mechanical coupling means to one another and to a common external auxiliary driving mechanism.
  • a circuit-breaker comprising in combination! an enclosure defining a first chamber; means for supplying pressurized insulating gas to said chamber normally to maintain said chamber at a predetermined pressure;
  • contact means within said chamber for defining, under one condition, an inner chamber isolated from said first chamber
  • said contact means including a sleevelike axially movable contact and a second contact engaged by one end of said sleevelike contact when said contact means is in said one condition, said sleevelike contact having a radially enlarged valve portion adjacent said one end thereof and a radially enlarged piston portion adjacent the other end thereof, said valve portion being in sealing contact with said second contact when said contact means is in said one condition whereby to maintain said pressure differential, and said valve portion and said piston portion being dimensional so that the forces exerted thereon due to said-pressure differential and which forces act in tipposite directions, are at least substantially mutually cancelled;
  • means including an external actuator and an actuating rod connecting said actuator to said sleevelike contact for overcoming small net force to separate said contacts and open said inner chamber to 'said first chamber so that the insulating gas rushes past said contacts and axially through said sleeve-like contact.
  • a circuit-breaker comprising, in combination:
  • a pair of electrically conductive members disposed in spaced relation to each other within said chamber, at least one of said members being fixed and including a tubular extension projecting therefrom toward the other member and a surrounding wall portion defining an annular cylinder with the outer surface of said tubular extens
  • a second sleevelike electrical'contact movable axially of said tubular extension between a closed condition in which one end thereof engages said first contact and an open condition in which said one end thereof is separated from said one contact, said one end of the second contact having a radially projecting shoulder thereon and said 7 other member having an annular surface portion sealingly engaged by said shoulder when said contacts are in closed condition, and the other end of said second contact having radially projecting piston portion engaging said wall portion of said annular cylinder whereby to define an isolated from the first mentioned inner chamber chamber;
  • means including an external actuator and an actuating rod connecting said actuator to said one contact for overcoming said small net force to separate said contacts.

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  • Circuit Breakers (AREA)
  • Driving Mechanisms And Operating Circuits Of Arc-Extinguishing High-Tension Switches (AREA)
  • Gas-Insulated Switchgears (AREA)
US719339A 1967-04-13 1968-04-08 Circuit-breaker with pressure balanced relatively movable contacts Expired - Lifetime US3564178A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL6705204A NL6705204A (fr) 1967-04-13 1967-04-13

Publications (1)

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US3564178A true US3564178A (en) 1971-02-16

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US719339A Expired - Lifetime US3564178A (en) 1967-04-13 1968-04-08 Circuit-breaker with pressure balanced relatively movable contacts

Country Status (7)

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US (1) US3564178A (fr)
JP (1) JPS4947109B1 (fr)
BE (1) BE701472A (fr)
DE (1) DE1665254C3 (fr)
GB (1) GB1214670A (fr)
NL (2) NL6705204A (fr)
SE (1) SE348594B (fr)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4962110U (fr) * 1972-09-12 1974-05-31
JPS5639221U (fr) * 1979-09-04 1981-04-13
FR2688934B1 (fr) * 1992-03-23 1994-05-06 Gec Alsthom Sa Disjoncteur rapide pour limiteur de courant supraconducteur.
CN111354606B (zh) * 2020-03-27 2021-10-29 浙江东禾工程设计有限公司 一种高压断路器

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE638785A (fr) *
DE1055644B (de) * 1958-08-08 1959-04-23 Voigt & Haeffner Ag Druckluftschalter mit einer Vorrichtung zur Blockierung des beweglichen Kontaktstueckes in der Ausschaltstellung beim Wegbleiben des Betriebsdruckes

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE638785A (fr) *
DE1055644B (de) * 1958-08-08 1959-04-23 Voigt & Haeffner Ag Druckluftschalter mit einer Vorrichtung zur Blockierung des beweglichen Kontaktstueckes in der Ausschaltstellung beim Wegbleiben des Betriebsdruckes

Also Published As

Publication number Publication date
SE348594B (fr) 1972-09-04
DE1665254C3 (de) 1975-07-10
DE1665254A1 (de) 1971-01-21
NL6705204A (fr) 1968-10-14
DE1665254B2 (de) 1974-11-28
JPS4947109B1 (fr) 1974-12-13
BE701472A (fr) 1968-01-02
GB1214670A (en) 1970-12-02
NL132914C (fr)

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