US3065322A - Gas blast circuit breaker - Google Patents

Gas blast circuit breaker Download PDF

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Publication number
US3065322A
US3065322A US77145A US7714560A US3065322A US 3065322 A US3065322 A US 3065322A US 77145 A US77145 A US 77145A US 7714560 A US7714560 A US 7714560A US 3065322 A US3065322 A US 3065322A
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US
United States
Prior art keywords
contact
movable
auxiliary
pressurized gas
main
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
US77145A
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English (en)
Inventor
Thellwell R Coggeshall
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.)
General Electric Co
Original Assignee
General Electric 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 General Electric Co filed Critical General Electric Co
Priority to US77145A priority Critical patent/US3065322A/en
Priority to DEG33825A priority patent/DE1172756B/de
Priority to GB45237/61A priority patent/GB987859A/en
Priority to FR882563A priority patent/FR1308366A/fr
Application granted granted Critical
Publication of US3065322A publication Critical patent/US3065322A/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
    • 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
    • H01H33/16—Impedances connected with contacts
    • H01H33/167—Impedances connected with contacts the impedance being inserted only while opening the switch
    • 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
    • H01H33/7015—Switches with separate means for directing, obtaining, or increasing flow of arc-extinguishing fluid characterised by flow directing elements associated with contacts
    • H01H33/7038—Switches with separate means for directing, obtaining, or increasing flow of arc-extinguishing fluid characterised by flow directing elements associated with contacts characterised by a conducting tubular gas flow enhancing nozzle
    • 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
    • H01H33/86—Switches with separate means for directing, obtaining, or increasing flow of arc-extinguishing fluid the flow of arc-extinguishing fluid under pressure from the contact space being controlled by a valve

Definitions

  • This invention relates to an electric circuit breaker of the gas blast type and, more particularly, to fluid-controlled actuating means for operating the contacts of this type of circuit breaker.
  • the circuit breaker of this invention comprises a set of main contacts and a set of auxiliary contacts disposed in a container filled with pressurized gas.
  • the main set of contacts is shunted by a resistor, and the other set is connected in series with the resistor for interrupting the resistor current after the main set of contacts has opened.
  • Extending from the region of the main contacts is an exhaust passage, the flow through which is controlled by a moveable one of the main contacts. So long as this movable main contact is in its closed position, flow. through the exhaust passage is blocked. But motion of the movable main contact in an opening direction efiects opening of this passage to permit pressurized gas to flow from the container through this passage via the arcing region between the main contacts.
  • This fioW of pressurized gas aids in extinguishing the usual arc resulting from contact separation. After this are has been ex tinguished, the auxiliary contacts are opened to interrupt the current that then flows through the resistor. After this resistor current has been interrupted, the main contacts are closed so as to terminate the flow of pressurized gas through the exhaust passage and thereby conserve the pressurized gas within the container for subsequent operations.
  • An object of this invention is to provide fluid-controlled actuating means, simple and compact in construction and reliable in operation, for operating the two sets of contacts in the sequence and manner set forth in the immediately preceding paragraph.
  • I provide a tank containing pressurized gas. Projecting into the tank is a pair of lead-in bushings respectively carrying at their inner ends movable and auxiliary contacts disposed in spaced-apart relationship. Located between the movable and auxiliary contacts and spaced therefrom is stationary supporting structure. The gap between the stationary supporting structure and the main contact is bridged by movable main contact means; and the gap between the supporting structure and the auxiliary contact is bridged by movable auxiliary contact means electrically connected to the movable main contact means.
  • Each of the movable contact means has a first surface on which the pressurized gas within the tank acts in a direction to open the movable contact means and a second surface on which pressurized gas acts in a direction to close said movable contact means.
  • the spaces adjacent the second surfaces contain pressurized gas when the movable contact means are in their respective closed positions.
  • Means is provided for exhausting these spaces to a low pressure region to permit the pressurized gas acting on the first surfaces to open said movable contact means.
  • Means responsive to opening of said movable contact means is provided for sealing off at least a portion of the second surface of said movable auxiliary contact means from the pressurized gas in the tank and for exposing the second surface of the movable main contact means to the pressurized gas within the tank to effect closing of the movable main contact means.
  • Resistance means is connected in parallel with the gap that results from opening of said movable main contact means and in series with the auxiliary contact means.
  • FIG. 1 is a side elevational view partly in section of a circuit breaker embodying one form of my invention.
  • FIG. 2 is an enlarged view of a portion of FIG. 1.
  • FIG. 2 depicts the parts of the circuit breaker when in the closed position.
  • PEG. 3 is a view similar to that of FIG. 2, but showing the parts of the circuit breaker in an open position.
  • a circuit breaker 14 ⁇ comprising a metallic tank 11, preferably at ground potential, that is normally filled with a pressurized arc-extinguishing and insulating gas, such as air. Projecting into the tank is a pair of spaced-apart lead-in bushings 1 1 and 15 for conducting electric current between the exterior and interior of the tank.
  • each of these bushings comprises a centrally-disposed conductive stud 16 extending longitudinally of the bushing and a pair of insulating shells 17 and 19 of conventional construction supporting the stud 16 on the top wall of the tank 11.
  • these insulating shells electrically isolate the conductive stud 16, which is at high potential, from the tank 11, which preferably is at ground potential.
  • the stud 16 of the right hand bushing is of a tubular construction, whereas the stud 16 of the left hand bushing is of a solid construction.
  • This stationary contact structure 18 has annular contact making portion Zll of suitable arc-resistant metal that is adapted to be engaged by a movable contact member 22.
  • the movable contact member 22 preferably has a conical portion 23 of arc-resistant material which is adapted to engage the contact-making portion 20 of the stationary contact structure when the contacts are closed.
  • Both the stationary contact structure 18 and the stud 16 on which it is supported are of a tubular configuration so as to define internally thereof an exhaust passage 2 that extends from the inner end of the stationary contact structure 18 to the outer end of the stud 16.
  • This stationary contact structure 30 has an annular contract-making portion 32 of suitable arc-resistant metal which is adapted to be engaged by additional movable contact structure 34.
  • This movable contact structure 34 has an annular contact-making portion 38 of arc-resistant metal which is adapted to engage the contact-making portion 32 of the stationary contact structure when this set of contacts is closed.
  • the first set of contacts 18, 22 is relied upon for the main portion of the current-interrupting duty, and these contacts will therefore be referred to hereinafter as the main contacts.
  • This restraining'means 82 comprises a latching lever 83 pivotally mounted on a stationary pivot $4 and biased in,
  • auxiliary contacts 30, 34 are relied upon for auxiliary duties (soon to be explained), and these contacts 36, 34 will therefore be referred to hereinafter as the auxiliary contacts.
  • a stationary metallic support This provided between the two contacts 22 and 34.
  • This stationary support 46 is shown mounted atop.
  • insulating columndZ serves 'to'electrically isolate thesupport 40 from the ground and tank 11.
  • the support 40 is of a hollow construction and comprises cylindrical bosses 44 and 46 extending therefrom at opposite ends.
  • the cylindrical boss 44 is slidably received within a cylindrical portion of the movable main contact 22 so that a conta-ct-controlling chamber 48 is provided adjacent the inner surface 50 of the movable main contact 22.
  • movable-main contact 22 is, in effect, a cylindrical piston telescopically mounted on the cylindrical boss 46.
  • suitable annular seal 52 is 'providedabout the outer periphery of tubular boss 414 to prevent pressurized gas from leaking into or out of the chamber 48 along the outer surface of boss 44.
  • the auxiliary contact 34 is in the form of a piston having a centrally displosed cylindrical sleeve integral This tubular boss 46.
  • An auxiliary contact-controlling chamber 56 is located internally of the sleeve 54, and a suitable annular seal 58 is provided in the outer periphery of the sleeve 54 to prevent pressurized gas from leaking into or out of the chamber '56 along the outer surface of sleeve
  • a pair of compression-type closing springs 66 and 62 are'provided.
  • Compression spring 60 acts between the stationary support 40' and the movable main contact 22 to exert a force on the movable contact 22 normally holding the contact 22 in its closed position of FIG. 2, whereas compression spring 62 acts between the stationary support 40 and the auxiliary contact 34 to exert a force on auxiliary contact 34 normally holding the auxiliary contact in its closed position of FIG. 2.
  • Contact-opening is effected by venting the contact-controlling chambers 48 and 56 through a controlling duct 65 of insulating material.
  • a suitable control valve shown schematically at 66 is located in this duct 65 to control the flow of pressurized gas therethrough.
  • the control valve 66 is preferably of the three-way type so that when closed, it establishes communication between the pressurized gas in the tank 11 and the contact-controlling chambers 56 and 48, as would be the case when the circuit breaker is in its closed position of FIGS. 1 and 2.
  • the pressurized gas in contact-controlling chambers 56 'and 48 is at the same pressure as the gas in the tank lll surrounding the contacts. Since the'surface area (50) of contact 22 that is exposed to gas pressure acting in a direction to move the contact closed is greater than the area of contact 22 exposed to pressure acting to force the contact open, there is a net force from the pressurized gas acting in a direction to hold the contact 22 closed.
  • auxiliary contacts 34, 3d are also opened.
  • the force for producing this auxiliary-contact opening action is made available by the venting of auxiliary contact-controlling chmiber 56 thatresults from opening of the controlling valve 66. More specifically, when the auxiliary contact-controlling chamber 56 is vented through the controlling duct 65, the pressure in auxiliary contactcentrolling chamber 56 drops, permitting the pressure acting on the left-hand side of piston lid to predominate. This predominating pressure provides a force tending to drive the contact 34 to the right away from the stationary contact against the bias of closing spring 62.
  • this sequence of opening operations can be attained by suitably controlling the relative masses of and the relative net opening forces on the twomovable contacts. But in a preferred form of my invention, I provide a more positive control over this opening sequence by including restraining means 32 that is elfective to latch the movable auxiliary c-ontact34 in its closed position of FIG. 2 untilthe movable main contact 22 has moved through substantially its entire opening stroke.
  • the latching lever 83 carries a roller 86 at its free end that engages a cam surface 87 on the auxiliary contact '34.
  • this roller 86 acts through the'cam surface 67 to hold the movable auxiliary contact 354 closed.
  • an actuating cam 39 suitably coupled to the main movable contact 22 is provided.
  • this actuating cam 86 engages a follower 88 carried by the latching lever 83 and forces the latching lever 83 counterclockwise about its pivot 84, thereby freeing the movable auxiliary contact for opening. Since there is then an opening force actingon the movable auxiliary contact 34, as was explained hereinabove, the movable auxiliary contact 34 responds by moving to the right from its posi- 7 tion of FIG. 2 to that of FIG. 3.
  • an annular seal it carried by the movable auxiliary contact 34 engages the left-hand end of a rigid tube 81 projecting from the movable main contact chamber 48.
  • This not only interrupts communication between the main contact chamber 48 and the vented duct 65, but also establishes direct communication between the pressurized gas in the tank 11 and the main contact-controlling chamber 43 via the opening 75 and the tube 32.
  • the result is that pressure in the contact-controlling chamber 48 soon builds up and produces a predominating force that drives the movable contact 22 to the right into its closed position, sealing off the exhaust passage 24 and thus terminating the flow of pressurized gas therethrough.
  • the period of time required for pressure to build up in the contact-controlling chamber 48 sufiiciently to drive the movable main contact 22 closed is governed by a metering pin 94 carried by the movable auxiliary contact 34.
  • This metering pin 91) slides into the bore of tube 32 as the movable auxiliary 34 moves into its fully-open position, thus providing a restricted orifice that controls the rate at which pressurized gas flows to the right through tube 82 to build up pressure for closing.
  • the metering pin 90 is so designed that suiiicient time elapses between the time the movable auxiliary contact reaches fully-open position and the time main movable contact 22 closes to assure that the resistor current has been interrupted at the auxiliary contacts 3%, 34 before the main contacts are reclosed.
  • the auxiliary movable contact 34 remains in its open position of FIG. 3 during this interval when the main movable contact is closing, since most of the auxiliary contact-controlling chamber 56 is still vented to atmosphere through the controlling duct 65. As a result, there is sufiicient net area of auxiliary contact 34 exposed to pressure from the tank If to hold the auxiliary contact 34 in its open position against the opposing bias of spring 62. By maintaining the contacts 34, 3t? open in this manner, the circuit is maintained in the desired open condition. Since the gap between auxiliary contacts 3% and 34 is located in the pressurized gas of the tank 11, this gap has sufficient dielectric strength to maintain a relatively highvoltage circuit open.
  • the controlling valve 66 is returned to its closed position of PEG. 1. This allows pressurized gas to flow from the tank 11 through the controlling duct 65 into the auxiliary contact-controlling chamber 56. The buildup of 6 pressure in auxiliary contact-controlling chamber 56 forces the movable auxiliary contact 34 to the left, finally returning the movable auxiliary contact to its closed position of FIG. 1 with the assistance of closing spring 62.
  • the central opening 75 in the auxiliary contact 34 does not significantly interfere with venting of the auxiliary contact controlling chamber 56 since this opening 75 is very small compared to the most restricted area through which venting takes place, e.g., the area between the fixed tube 82 and the sleeve 54 on the movable auxiliary contact
  • any pressurized gas that flows in through opening 75 during venting is exhausted through the controlling duct 65 before any significant pressure can be built up in the contact-controlling chamber 56 during venting of this chamber 56.
  • An electric circuit breaker of the gas blast type comprising a tank adapted to contain pressurized gas, a pair of lead-in bushings projecting into said tank, a main and an auxiliary contact respectively mounted on the inner ends of said bushings in spaced-apart relationship to each other, stationary supporting structure located between said contacts and spaced therefrom, movable main contact means bridging the gap between said stationary supporting structure and said main contact, movable auxiliary contact means bridging the gap between said stationary supporting structure and said auxiliary contact, means for electrically interconnecting said movable main and movable auxiliary contact means, each of said movable contact means having a first surface on which the pressurized gas within said tank acts in a direction to open said movable contact means and a second surface on which pressurized gas acts in a direction to close said movable contact means, the spaces adjacent said second surfaces containing pressurized gas when said movable contact means are in their respective closed positions, means for exhausting said spaces to a low pressure region to permit the pressurized gas
  • An electric circuit breaker of the gas blast type comprising a tank adapted to contain pressurized gas, a pair of lead-in bushings projecting into said tank, a main and an auxiliary contact respectively mounted on the inner ends of said bushings in spaced-apart relationship 28 to each other, stationary supporting structure located between said contact and spaced therefrom, movable main contact means bridging the gap between said stationary supporting structure and said main contact, movable auxiliary contact means bridging the gap between said stationary supporting structure and said auxiliary contact, means for electrically interconnecting said movable main and movable auxiliary contact means, each of said movable contact means including 'a piston containing a hollow portion constituting a contact-controlling chamber in which pressurized gas acts on said piston in a direction to close said movable contact means, each of said movable'contact means having another surface on which pressurized gas within said tank acts in a direction to open said movable contact means, said contact-controlling chambers containing pressurized gas when said movable contact

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US77145A 1960-12-20 1960-12-20 Gas blast circuit breaker Expired - Lifetime US3065322A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US77145A US3065322A (en) 1960-12-20 1960-12-20 Gas blast circuit breaker
DEG33825A DE1172756B (de) 1960-12-20 1961-12-15 Druckgasschalter
GB45237/61A GB987859A (en) 1960-12-20 1961-12-18 Improvements in gas blast circuit breaker
FR882563A FR1308366A (fr) 1960-12-20 1961-12-20 Disjoncteur à air comprimé

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US77145A US3065322A (en) 1960-12-20 1960-12-20 Gas blast circuit breaker

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US3065322A true US3065322A (en) 1962-11-20

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Application Number Title Priority Date Filing Date
US77145A Expired - Lifetime US3065322A (en) 1960-12-20 1960-12-20 Gas blast circuit breaker

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US (1) US3065322A (de)
DE (1) DE1172756B (de)
GB (1) GB987859A (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3590186A (en) * 1968-12-19 1971-06-29 Allis Chalmers Mfg Co Vacuum interrupter having series connected resistor and shunting means for the latter

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1965551A (en) * 1931-07-06 1934-07-03 Bbc Brown Boveri & Cie Electric circuit breaker
GB582599A (en) * 1944-07-07 1946-11-21 English Electric Co Ltd Improvements in electric circuit breakers
US2459600A (en) * 1944-12-14 1949-01-18 Westinghouse Electric Corp Compressed gas circuit interrupter
US2665351A (en) * 1951-02-09 1954-01-05 Asea Ab Arrangement in air blast circuit breaker provided with damping resistance
US2911507A (en) * 1957-06-21 1959-11-03 Ite Circuit Breaker Ltd Recirculating gas blast interrupter
US2970198A (en) * 1957-02-18 1961-01-31 Westinghouse Electric Corp Compressed-gas circuit interrupter

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE647141C (de) * 1933-08-01 1937-06-29 Bbc Brown Boveri & Cie Elektrischer Schalter
BE538744A (de) * 1954-06-04
US2803724A (en) * 1954-06-04 1957-08-20 Asea Ab Operating device for air blast circuit breakers

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1965551A (en) * 1931-07-06 1934-07-03 Bbc Brown Boveri & Cie Electric circuit breaker
GB582599A (en) * 1944-07-07 1946-11-21 English Electric Co Ltd Improvements in electric circuit breakers
US2459600A (en) * 1944-12-14 1949-01-18 Westinghouse Electric Corp Compressed gas circuit interrupter
US2665351A (en) * 1951-02-09 1954-01-05 Asea Ab Arrangement in air blast circuit breaker provided with damping resistance
US2970198A (en) * 1957-02-18 1961-01-31 Westinghouse Electric Corp Compressed-gas circuit interrupter
US2911507A (en) * 1957-06-21 1959-11-03 Ite Circuit Breaker Ltd Recirculating gas blast interrupter

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3590186A (en) * 1968-12-19 1971-06-29 Allis Chalmers Mfg Co Vacuum interrupter having series connected resistor and shunting means for the latter

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Publication number Publication date
GB987859A (en) 1965-03-31
DE1172756B (de) 1964-06-25

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