US2887550A - Gas-blast circuit breakers - Google Patents

Gas-blast circuit breakers Download PDF

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Publication number
US2887550A
US2887550A US639699A US63969957A US2887550A US 2887550 A US2887550 A US 2887550A US 639699 A US639699 A US 639699A US 63969957 A US63969957 A US 63969957A US 2887550 A US2887550 A US 2887550A
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United States
Prior art keywords
piston
contact
switching
diameter
switching contact
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Expired - Lifetime
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US639699A
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English (en)
Inventor
Nijland Hendrik A Hidde
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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
    • H01H33/83—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 wherein the contacts are opened by the flow of air or gas

Definitions

  • GAS-BLAST CIRCUIT BREAKERS May 19,- 1959 United States Patent O ce
  • the invention relates to a gas-blast circuit breaker comprising in combination an arcing compartment adapted to be supplied with compressed extinguishing gas, mounted in said compartment at least one switching contact having an opening for the discharge of extinguishing gas from said compartment and at least one second switching contact cooperating with the rst mentioned one both electrically and as a valve in order to open and to close said discharge opening, at least one of said cooperating switching contacts being mounted lfor movement against spring pressure in the switching-oil?
  • a cylinder having one end in communication with said arcing compartment, a piston slidably mounted in said cylinder and adapted to drive said movable switching contact away from the other switching contact and a lost motion connection provided between said piston and said movable switching contact, said piston having a reduced portion adapted to engage a part of the cylinder chamber, which part has a correspondingly reduced diameter and is in permanent communication with the arcing compartment, said lost motion connection permitting the piston, which during the switching-oli operation is exposed to the pressure of the gas in the arcing compartment first with its reduced portion and thereupon with its portion of greater diameter and is moved against spring pressure at least during the first part of its stroke, to be connected with the movable switching contact only after it has left the part of reduced diameter of the cylinder chamber.
  • the spring keeping the switching contacts pressed one upon the other when circuit breaker is in its closed position is so dimensioned as to exert not only the contact pressure required under normal operating circumstances but also the considerably higher contact pressure, which is necessary during the period when, during the switching-ott operation under abnormal circumstances, the piston moves freely due to the lost motion connection. That is why these circuit breakers are provided with relatively strong springs for biasing the switching contacts towards one another.
  • the invention has for its object to alter the construction of the above mentioned circuit breakers such as to avoid the necessity to over-dimension the contact pressure, whereby a saving of room especially in axial direction is realized.
  • lt consists in that the smallest diameter of the annular contact area between the two cooperating switching contacts is greater than the diameter of the reduced piston portion. In that case the extinguishing gas itself keeps the switching contact to be moved by the piston pressed on the other switching contact as long as the piston moves freely.
  • the mentioned diameter of the contact area must be smaller than the diameter of the greater piston area. lf this should be not so the piston would not be able lto withdraw the movable switching contact from the other contact and to break the circuit.
  • the invention makes it possible to combine these two springs.
  • the provision of an abutment on the switching contact adapted to be moved by the piston during the switching-oit operation is recommended and the construction must be such as to allow the piston to be pressed by spring pressure against said abutment and to keep said movable switching contact resiliently pressed on the other switching contact, when the circuit breaker is in its stationary condition.
  • the combination of the two springs makes it possible to simplify the construction and to reduce the axial dimension of the circuit breaker considerably.
  • FIG. 1 is a metal casing
  • 2 is the insulating inner wall of said casing
  • 3 is a metal contact ring forming part of said inner wall and connected with the conductor of a leading-in insulator 4.
  • a switching element mounted within the double-walled casing 1, 2, 3 is a switching element, which is provided with a tubular fixed switching contact 6 attached to a tube 5 of insulating material and electrically connected to the contact ring 3.
  • the fixed switching contact 6 has an opening 7 for the discharge of extinguishing gas from the arcing compartment 8 formed ⁇ within the tube 5 and the fixed switching contact 6.
  • a movable switching contact 9 adapted to act as a valve and to close the discharge opening 7 for the extinguishing gas cooperates with the fixed switching contact 6.
  • Said switching Contact 9 is provided with a cylindrical stem 10, which is passed through the end wall of a cylinder 11 attached to the end of a tube 12 of insulating material, which is coaxially mounted within the tube 5.
  • the cylinder 11 is provided with a piston 13, which is mounted on the stem 10 of the switching contact 9 and is adapted to be moved freely through a certain distance in axial direction. The free movement of the piston is limited on one side by axially extending ribs 14 formed on the stem 10 and on the other side by a head of the stem.
  • This head is constructed as a bushing contact 15, which is engaged by the end 16 of a switching rod 17 when the circuit breaker is in its closed condition.
  • the ribs 14 serve also to center the stem 10 in the cylinder 11 and to guide the movable switching contact 9.
  • the piston 13 is loaded by a compression spring 18 and is urged by the latter towards .a position, in which the piston engages with a part 13a having a reduced diameter a titting opening 19 in the end wall of the cylinder. In this position the piston abuts against ribs 14.
  • the circuit breaker is constructed, in such a manner, that the smaller diameter of the conical contact area 20 or seat between the fixed switching contacts 6 and the movable switching contact 9 is greater than the diameter of the opening 19 or the diameter of the smaller piston area 13a of the stepped piston 13.
  • the result thereof is that, when extinguishing gas under pressure is supplied to the arcing compartment 8 through the space 21, the force with which the movable switching contact 9 is pressed against the seat of the fixed switching contact 6 is greater than the force exerted by the extinguishing gas on the smaller piston area 13a.
  • the force exerted on the piston 13 becomes greater than the pressure of the spring 18 the piston is lifted but the switching contact 9 ⁇ remains pressed against the fixed contact 6.
  • the spring 18 urges both the piston 13 and the switching contact 19 back into their positions in which the switching contact 9 engages the seat 20 of the xed switching contact 6.
  • the spring 1S serves also to generate the contact pressure in the closed condition of the circuit breaker.
  • a gas-blast circuit breaker comprising in combination an arcing compartment adapted to be supplied with compressed extinguishing gas, mounted in said compartment a switching contact having an opening for the discharge of extinguishing gas from Vsaid compartment and a second switching contact cooperating with the first mentioned contact both electrically and as a valve in order to open and to close said discharge opening, one of said cooperating switching contacts being mounted for movement against spring pressure in a switching-ofi ⁇ direction, a cylinder having one end in communication with said arcing compartment, a piston slidably mounted in said cylinder' and adapted to drive said movable switching contact away from the other vswitching contact and a lost motion connection provided between said piston and said movable switching contact, said piston having a reduced portion adapted to engage a part of the cylinder chamber, which part has a correspondingly reduced diameter and is in permanent communication with the arcing chamber, said lost motion connection permitting the piston, which during the switching-0E operation is exposed to the pressure of the gas in the arcing compartment
  • a gas-blast circuit breaker as claimed in claim 1 including an abutment on ⁇ the switching contact adapted to be moved by the piston during the switching-ott operation, a spring biasing said piston against said abutment in a direction to keep said movableswitching contact pressed on the other switching contact when the circuit breaker is in its closed position.
  • a fluid blast circuit breaker including an arcing chamber having a xed discharge nozzle contact and a pressure operated movable contact cooperating therewith, a cylinder in said arcing chamber having a passageway providing communication with the arcing chamber, a piston reciprocable in the cylinder and arranged with only a rst eective area of reduced diameter in permanent communication with the arcing chamber through said passageway and having a second larger eiective area with a greater diameter, a lost-motion connection between the piston and the movable contact, a single resilient means biasing the piston in a iluid pressure resisting direction into a seated position closing said passageway and cooperating with the piston in biasing the movable contact in a direction toward a seated position engaging and closing the nozzle contact, means for selectively introducing fluid pressure into said arcing chamber, and the greatest diameter of an annular seating area defined by the two cooperating contacts being smaller than the greater diameter of said piston and the smallest diameter of said seating area being greater

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  • Circuit Breakers (AREA)
US639699A 1956-02-15 1957-02-12 Gas-blast circuit breakers Expired - Lifetime US2887550A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL346929X 1956-02-15

Publications (1)

Publication Number Publication Date
US2887550A true US2887550A (en) 1959-05-19

Family

ID=19784919

Family Applications (1)

Application Number Title Priority Date Filing Date
US639699A Expired - Lifetime US2887550A (en) 1956-02-15 1957-02-12 Gas-blast circuit breakers

Country Status (7)

Country Link
US (1) US2887550A (de)
BE (1) BE547466A (de)
CH (1) CH346929A (de)
DE (1) DE1025486B (de)
FR (1) FR1154459A (de)
GB (1) GB825678A (de)
NL (4) NL219557A (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3629532A (en) * 1970-02-20 1971-12-21 Sun Electric Corp Immediately responsive fluid flow operated switch with normally closed spring contact in flow channel

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2240233A (en) * 1938-05-27 1941-04-29 Bbc Brown Boveri & Cie Gas blast circuit breaker
US2310905A (en) * 1938-06-03 1943-02-09 English Electric Co Ltd Electrical switching apparatus
US2500429A (en) * 1942-02-19 1950-03-14 Nijland Hendrik A Hidde Electric gas blast circuit breaker

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2240233A (en) * 1938-05-27 1941-04-29 Bbc Brown Boveri & Cie Gas blast circuit breaker
US2310905A (en) * 1938-06-03 1943-02-09 English Electric Co Ltd Electrical switching apparatus
US2500429A (en) * 1942-02-19 1950-03-14 Nijland Hendrik A Hidde Electric gas blast circuit breaker

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3629532A (en) * 1970-02-20 1971-12-21 Sun Electric Corp Immediately responsive fluid flow operated switch with normally closed spring contact in flow channel

Also Published As

Publication number Publication date
DE1025486B (de) 1958-03-06
NL91916C (de)
FR1154459A (fr) 1958-04-10
NL204555A (de)
NL87728C (de)
CH346929A (de) 1960-06-15
BE547466A (de)
NL219557A (de)
GB825678A (en) 1959-12-16

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