Vacuum-type circuit interrupter having a stroke length dependent upon current magnitude

Claim 2

A vacuum-type circuit interrupter for highly repetitive switching duty comprising: a. a highly evacuated housing, b. a pair of relatively movable contacts within said housing that have a position of engagement, c. an operating member projecting into said housing from the exterior thereof and coupled to one of said contacts, d. means comprising said operating member for moving said one contact through an opening stroke that separates said contacts and interrupts the circuit therethrough, e. a flexible metal bellows providing a vacuumtight seal between said operating member and said housing, f. and stroke-length control means responsive to current through said contacts for varying the length of said opening stroke in accordance with the magnitude of said current, said strokelength control means causing the length of said opening stroke to the greater for short circuit current interruptions than for light-current interruptions, thus allowing light-current interruptions to be effected with a reduced flexure of said bellows, said stroke-length control means comprising: i. a first stop for limiting the opening stroke to a relatively short length, ii. a second stop effective when said first stop is disabled for limiting the opening stroke to a greater length, and iii. current-sensitive means for disabling said first stop when the current through said contacts exceeds a predetermined value, thereby rendering said second stop effective to govern the stroke length.

Claim 3

A vacuum-type circuit interrupter for interrupting short circuit currents and capacitive currents comprising: a. a highly evacuated housing, b. a pair of relatively movable contacts within said housing that have a position of engagement, c. an operating member projecting into said housing from the exterior thereof and coupled to one of said contacts, d. means comprising said operating member for moving said one contact through an opening stroke that separates said contacts and interrupts the circuit therethrough, E. a flexible metal bellows providing a vacuumtight seal between said operating member and said housing, f. and stroke-length control means responsive to current through said contacts for varying the length of said opening stroke in accordance with the magnitude of said current, said current-responsive control means causing the length of said opening stroke to be greater for light-current interruptions than for heavy current interruptions, thus providing a stroke of greater length for capacitance switching operations than for short circuit current interruptions.

Claim 4

A vacuum-type circuit interrupter for interrupting short circuit currents and capacitive currents comprising: a. a highly evacuated housing, b. a pair of relatively movable contacts within said housing that have a position of engagement, c. an operating member projecting into said housing from the exterior thereof and coupled to one of said contacts, d. means comprising said operating member for moving said one contact through an opening stroke that separates said contacts and interrupts the circuit therethrough, E. a flexible metal bellows providing a vacuumtight seal between said operating member and said housing, f. and stroke-length control means responsive to current through said contacts for varying the length of said opening stroke in accordance with the magnitude of said current, said current-responsive control means causing the length of said opening stroke to be greater for light-current interruptions than for heavy current interruptions, thus providing a stroke of greater length for capacitance switching operations than for short circuit current interruptions.

Claim 5

A vacuum-type circuit interrupter as defined in claim 2 in which said stroke-length control means comprises: a. a first stop that is normally disabled but which is effective upon removal of said disability to limit said opening stroke to a relatively short value, b. a second stop that limits said opening stroke to a greater length when said first stop is disabled, c. and current-sensitive means for removing said disability when the current through said contacts exceeds a predetermined value, thereby rendering said first stop effective to govern the stroke length on short circuit current interruptions.

Claim 6

In a polyphase vacuum circuit breaker comprising a plurality of vacuum interrupters for the respective phases of the circuit, each vacuum interrupter comprising: a. a highly evacuated housing, b. a pair of relatively movable contacts within said housing that have a position of engagement, c. an operating member projecting into said housing from the exterior thereof and coupled to one of said contacts, d. means comprising said operating member for moving said one contact through an opening stroke that separates said contacts and interrupts the circuit therethrough, e. a flexible metal bellows providing a vacuumtight seal between said operating member and said housing, f. and stroke-length control means responsive to current through said contacts for varying the length of said opening stroke in accordance with the magnitude of said current, the stroke-length control means of each phase being operable independently of the stroke-length control means of the other phases for varying the stroke length of the interrupter in any one phase in accordance with the current in that phase without affecting the stroke length in the other phases.

Claim 7

In a polyphase vacuum circuit breaker comprising a plurality of vacuum interrupters for the respective phases of the circuit, each vacuum interrupter comprising: a. a highly evacuated housing, b. a pair of relatively movable contacts within said housing that have a position of engagement, c. an operating member projecting into said housing from the exterior thereof and coupled to one of said contacts, d. means comprising said operating member for moving said one contact through an opening stroke that separates said contacts and interrupts the circuit therethrough, e. a flexible metal bellows providing a vacuumtight seal between said operating member and said housing, f. and stroke-length control means responsive to current through said contacts for varying the length of said opening stroke in accordance with the magnitude of said current, the stroke-length control means of each phase being operable independently of the stroke-length control means of the other phases for varying the stroke length of the interrupter in any one phase in accordance with the current in that phase without affecting the stroke length in the other phases.

Claim 8

In a polyphase vacuum circuit breaker comprising a plurality of vacuum interrupters for the respective phases of the circuit, each vacuum interrupter comprising: a. a highly evacuated housing, b. a pair of relatively movable contacts within said housing that have a position of engagement, c. an operating member projecting into said housing from the exterior thereof and coupled to one of said contacts, d. means comprising said operating member for moving said one contact through an opening stroke that separates said contacts and interrupts the circuit therethrough, e. a flexible metal bellows providing a vacuumtight seal between said operating member and said housing, f. and stroke-length control means responsive to current through said contacts for varying the length of said opening stroke in accordance with the magnitude of said current; the combination of: g. a linkage connected to the interrupters in all phases for imparting closing motion thereto after an opening operation, h. latching means for holding said linkage in an operated position after a closing operation to hold said interrupters closed, i. said latching means being releasable to permit opening of said interrupters, j. a plurality of opening operators respectively biasing the interrupters toward open position and operable upon release of said latching means to separate the contacts of their respective interrupters, and k. a lost-motion connection between said linkage and each interrupter which allows the opening stroke in the associated interrupter to be terminated at a relatively short value by said stroke-length control means without blocking continued opening travel in the other interrupters.

Claim 9

In a polyphase vacuum circuit breaker comprising a plurality of vacuum interrupters for the respective phases of the circuit, each vacuum interrupter comprising: a. a highly evacuated housing, b. a pair of relatively movable contacts within said housing that have a position of engagement, c. an operating member projecting into said housing from the exterior thereof and coupled to one of said contacts, d. means comprising said operating member for moving said one contact through an opening stroke that separates said contacts and interrupts the circuit therethrough, e. a flexible metal bellows providing a vacuumtight seal between said operating member and said housing, f. and stroke-length control means responsive to current through said contacts for varying the length of said opening stroke in accordance with the magnitude of said current; the combination of: g. a linkage connected to the interrupters in all phases for imparting closing motion thereto after an opening operation, h. latching means for holding said linkage in an operated position after a closing operation to hold said interrupters closed, i. said latching means being releasable to permit opening of said interrupters, j. a plurality of opening operators respectively biasing the interrupters toward open position and operable upon release of said latching means to separate the contacts of their respective interrupters, and k. a lost-motion connection between said linkage and each interrupter which allows the opening stroke in the associated interrupter to be terminated at a relatively short value by said stroke-length control means without blocking continued opening travel in the other interrupters.