Gas blast circuit breaker with puffer piston having an electrodynamic assist in the form of axially overlapping coils

Claim 2

A circuit breaker for cutting off a load current to be carried through a contact between a stationary and movable main contactors, both contactors being opposite to each other, in which said current is diverted to an electromagnetic actuator means in an operation to separate said movable contactor from said stationary contactor by an external actuator and an electromagnetic force developed by said current is applied together with a driving force of said external actuator to compress an arc-extinguishing gas which is directed to the arc to extinguish the same, said electromagnetic actuator means comprising at least one primary coil to be diverted with said load current, a short circuit coil associated with said primary coil, such that a current is induced to said short circuit coil by said current diverted to said primary coil to thereby produce the electromagnetic force between both said coils, means for movably supporting one of said primary coil, and said short circuit coil, and compressing means for the arc-extinguishing gas mechanically connected with the movable one of said primary coil and said short circuit coil, said primary coil and/or said short circuit coil having a large axial length such that the electromagnetic force acting therebetween has a flat characteristic, the movable one of said primary coil and said short circuit coil being brought into overlapped relation with the other in a part of the moving stroke thereof.

Claim 3

A circuit breaker as claimed in claim 1, in which said primary coil in said electromagnetic actuator means is asymmetrically wound so as to produce a magnetic field which is asymmetrical in the axial direction of said primary coil.

Claim 4

A circuit breaker as claimed in claim 1, in which said electromagnetic actuator means comprises short circuiting means for short circuiting said primary coil during or prior to throw-in operation and releasing said primary coil during or prior to breaking operation.

Claim 5

A circuit breaker as claimed in claim 1, in which said short circuit coil in said electromagnetic actuator means is axially split in at least one portion thereof and the split portion is short-circuited with the movement of said primary coil or said short circuit coil.

Claim 6

A circuit breaker for cutting off a load current to be carried through a contact between a stationary and movable main contactors, both contactors being opposite to each other, in which said current is diverted to an electromagnetic actuator means in an operation to separate said movable contactor from said stationary contactor by an external actuator and an electromagnetic force developed by said current is applied together with a driving force of said external actuator to compress an arc-extinguishing gas which is directed to the arc to extinguish the same, said electromagnetic actuator means comprising at least one primary coil to be diverted with said load current, a short circuit coil associated with said primary coil such that a current is induced to said short circuit coil by said current diverted to said primary coil thereby to produce the electromagnetic force between both said coils, a member of magnetic material for attracting said primary coil toward it, means for movably supporting One of said primary coil or said short circuit coil and said member of magnetic material, and compressing means for the arc-extinguishing gas mechanically connected with said movable one of said primary coil or said short circuit coil and said member of magnetic material, said primary coil and/or said short circuit coil having a large axial length such that the electromagnetic repulsive force acting therebetween has a flat characteristic, one of said primary coil and said short circuit coil being brought into overlapped relation with the other in a part of the moving stroke thereof.

Claim 7

A circuit breaker for cutting off a load current to be carried through a contact between a stationary and movable main contactors, both contactors being opposite to each other, in which said current is diverted to an electromagnetic actuator means in an operation to separate said movable contactor from said stationary contactor by an external actuator and an electromagnetic force developed by said current is applied together with a driving force of said external actuator to compress an arc-extinguishing gas which is directed to the arc to extinguish the same, said electromagnetic actuator means comprising at least one primary coil to be diverted with said load current, a short circuit coil associated with said primary coil such that a current is induced to said short circuit coil by said current diverted to said primary coil thereby to produce the electromagnetic force between both said coils, a member of magnetic material for attracting said primary coil toward it, means for movably supporting One of said primary coil or said short circuit coil and said member of magnetic material, and compressing means for the arc-extinguishing gas mechanically connected with said movable one of said primary coil or said short circuit coil and said member of magnetic material, said primary coil and/or said short circuit coil having a large axial length such that the electromagnetic repulsive force acting therebetween has a flat characteristic, one of said primary coil and said short circuit coil being brought into overlapped relation with the other in a part of the moving stroke thereof.

Claim 8

A circuit breaker according to claim 5, wherein said means for movably supporting primary coil includes an actuating rod fixedly attached to a first support member upon which an annular support member rests, said primary coil being disposed on said annular support member, and wherein said compressing means includes a puffer chamber fixedly mounted in a first cylinder, which in turn, is affixed to said short circuit coil at a flanged portion thereof, whereby during breaking operation, said arc-extinguishing gas is compressed in a puffer chamber formed by said cylinder and the flange portion of said short circuit coil.

Claim 9

A circuit breaker according to claim 6, wherein said movable contactors are formed by a pair of concentrically disposed conductors centrally arranged within said chamber, a center one of which has a conductor contact at the end thereof adjacent said primary coil while the outer one of said concentrically disposed conductors has formed thereon said movable main contactor and wherein a shorting switch is located within said primary coil and has one of its contacts affixed to said annular support member and the other of its contacts fixably attached to the winding of said primary coil, whereby, upon movement of said actuating rod, said switch will open or close dependent upon the direction of movement of said rod and said primary coil will be short or open circuited in response thereto.

Claim 10

A circuit breaker comprising: a pair of terminals through which current normally flows during the closed condition of said breaker; a stationary contactor electrically connected with one of said terminals; a movable contactor disengagably slidable with respect to said stationary contactor, whereby current flows directly between said contactors during normally closed operation of said breaker and an arc forms between said contactors upon disengagement thereof during breaking; means, coupled to said contactors, for supplying an arc-extinguishing gas upon disengagement of said contactors; means for separating said contactors from each other, so as to interrupt the current normally flowing between said terminals, comprising an electromagnetic actuator arrangement including: means for electromagnetically separating said contactors comprising: a primary coil, normally short circuited during the flow of current between said terminals, and a short circuit coil electrically connected to said movable contactors, one of said primary and secondary coils having a large axial length such that the electromagnetic force acting therebetween has a flat characteristic; and means for inducing an electromagnetic displacing force between said primary coil and said short circuit coil including: means for simultaneously mechanically means for simultaneously mechanically displacing said contactors with respect to each other and for displacing said primary coil relative to said short circuit coil and for initiating current flow therebetween, said simultaneous displacing means including means for terminating the normally short-circuited condition of said primary coil and providing a current path therethrough, whereby an electromagnetic field between said primary and said short circuit coil will be generated to assist the separation of said contactors by said displacing means.

Claim 11

A circuit breaker comprising: a pair of terminals through which current normally flows during the closed condition of said breaker; a stationary contactor electrically connected with one of said terminals; a movable contactor disengagably slidable with respect to said stationary contactor, whereby current flows directly between said contactors during normally closed operation of said breaker and an arc forms between said contactors upon disengagement thereof during breaking; means, coupled to said contactors, for supplying an arc-extinguishing gas upon disengagement of said contactors; means for separating said contactors from each other, so as to interrupt the current normally flowing between said terminals, comprising an electromagnetic actuator arrangement including: means for electromagnetically separating said contactors comprising: a primary coil, normally short circuited during the flow of current between said terminals, and a short circuit coil electrically connected to said movable contactors, one of said primary and secondary coils having a large axial length such that the electromagnetic force acting therebetween has a flat characteristic; and means for inducing an electromagnetic displacing force between said primary coil and said short circuit coil including: means for simultaneously mechanically means for simultaneously mechanically displacing said contactors with respect to each other and for displacing said primary coil relative to said short circuit coil and for initiating current flow therebetween, said simultaneous displacing means including means for terminating the normally short-circuited condition of said primary coil and providing a current path therethrough, whereby an electromagnetic field between said primary and said short circuit coil will be generated to assist the separation of said contactors by said displacing means.

Claim 12

A circuit breaker according to claim 8, wherein said means for supplying an aRc-extinguishing gas comprises a movable puffer cylinder mechanically coupled to said movable contactor and a stationary puffer piston affixed to said short circuit coil.

Claim 13

A circuit breaker according to claim 8, wherein said movable contactor comprises a central contactor element and a tubular member, said tubular member being electrically connected directly to said short circuit coil and further including means, connected to said central contactor elements, for normally directing said central contactor through said short circuit coil to one of said terminals and for connecting said central contactor element through said primary coil and said short circuit coil to said one of said terminals during the breaking operation of said breaker.

Claim 14

A circuit breaker according to claim 10, wherein said normally directly connecting means comprises a knife edge contactor electrically connected to one end of said primary coil and a conductor connected directly to said central contactor element and the other end of said primary coil, said knife edge contactor and said contactor being displaced with respect to each other.