Pneumatic power-unit having a driving piston and an exhaust valve

Claim 2

An operating mechanism for a circuit-interrupter including in combination: a. means defining separable contact means; b. a movable member; c. means rendering opening and closing motions of said separable contact means responsive to the movement of said movable member (29); d. a pneumatic operator including a driving-piston operable within a pneumatic operating cylinder and having a piston-rod extending externally out of said pneumatic operating cylinder; e. said piston rod being connected with said movable member (29) to cause the actuation thereof; f. said piston-rod extending only out of one end of the operating cylinder on one working side of the driving piston; g. the other end of the operating cylinder on the nonworking side of the piston being closed with respect to the piston-rod; h. valve means normally maintaining high-pressure gas within said pneumatic operating cylinder on both the driving and nondriving sides of the driving-piston to thereby extend the piston-rod outwardly by differential piston action; and, i. means for operating said valve means and exhausting gas from the non-driving side of the driving-piston at said other end of the cylinder to thereby move the driving-piston toward the closed end of the operating cylinder and the movable member (29) to close the breaker contacts.

Claim 3

The combination according to claim 1, wherein the movable member is a rotatable main operating lever pivotally mounted upon a stationary pivot and connected to said piston-rod.

Claim 4

The combination according to claim 2, wherein the connection between the piston-rod and the rotatable main operating lever is a lost-motion connection, whereby the driving-piston may assume its reset position without interference with the rotatable main operating lever.

Claim 5

The combination according to claim 1, wherein a collapsible toggle-linkage releasably maintains the movable member in its closed position.

Claim 6

The combination according to claim 4, wherein a holding means including a magnetically-actuated trigger-arm maIntains the collapsible toggle-linkage in an underset condition.

Claim 7

The combination according to claim 1, wherein opening accelerating spring means tends to bias the movable contacts of the circuit-interrupter in the opening direction, and a lost-motion connection is provided between the movable member and the piston-rod of the pneumatic operator.

Claim 8

The combination according to claim 1, wherein the valve means includes a normally-open three-way control valve, and the movable member comprises a rotatable operating lever pivotally mounted upon a stationary pivot and having a lost-motion connection with the piston-rod of the pneumatic operator.

Claim 9

The combination according to claim 3, wherein the lost-motion connection is an elongated slot provided in the piston-rod.

Claim 10

The combination according to claim 1, wherein the normal reset position of the driving-piston with high-pressure gas existing on both sides thereof is intermediate the ends of the pneumatic operating cylinder and against a stop portion provided on the pneumatic operating cylinder.

Claim 11

A pneumatic power-unit including, in combination: a. means defining an operating cylinder; b. a driving piston operable within said operating cylinder and responsive to the gas-pressure conditions existing therewithin; c. a piston-rod fixedly secured to and movable with said driving piston and responsive to the movement thereof; d. said piston-rod projecting externally of said operating cylinder at one end thereof through a first open cylinder-head and having an effective cross-sectional area of ''''A''''; e. a first pneumatic region (76) defined by said driving piston, the inner side walls of the operating cylinder and said first open cylinder-head of the operating cylinder at said one end of the operating cylinder; f. a second pneumatic region (61) disposed on the other side of said operating piston from said first pneumatic region; g. high-pressure gas conditions existing in said first pneumatic region at all times during operation of the pneumatic power unit; h. operating means including a three-way control valve for alternately pressurizing or exhausting said second pneumatic region; i. the pressurization level of said second pneumatic region being substantially at the same gas-pressure level as said constant-pressure gas-level of the first pneumatic region; and, j. the cross-sectional area ''''A'''' of said piston-rod being of sufficient adequate cross-sectional area to rapidly retract, by differential piston action, the operating movement of the operating piston toward said one end of the operating cylinder, whereby pressurization of the second pneumatic region will operatively move the piston-rod toward said first open cylinder-head of the operating cylinder, and exhausting of the second pneumatic region by operation of said control-valve will correspondingly effect driving inward motion of the operating piston and the piston-rod toward the other or closed second cylinder-head for retracting purposes of the operating piston.

Claim 12

A pneumatic power-unit including, in combination: a. means defining an operating cylinder; b. a driving piston operable within said operating cylinder and responsive to the gas-pressure conditions existing therewithin; c. a piston-rod fixedly secured to and movable with said driving piston and responsive to the movement thereof; d. said piston-rod projecting externally of said operating cylinder at one end thereof through a first open cylinder-head and having an effective cross-sectional area of ''''A''''; e. a first pneumatic region (76) defined by said driving piston, the inner side walls of the operating cylinder and said first open cylinder-head of the operating cylinder at said one end of the operating cylinder; f. a second pneumatic region (61) disposed on the other side of said operating piston from said first pneumatic region; g. high-pressure gas conditions existing in said first pneumatic region at all times during operation of the pneumatic power unit; h. operating means including a three-way control valve for alternately pressurizing or exhausting said second pneumatic region; i. the pressurization level of said second pneumatic region being substantially at the same gas-pressure level as said constant-pressure gas-level of the first pneumatic region; and, j. the cross-sectional area ''''A'''' of said piston-rod being of sufficient adequate cross-sectional area to rapidly retract, by differential piston action, the operating movement of the operating piston toward said one end of the operating cylinder, whereby pressurization of the second pneumatic region will operatively move the piston-rod toward said first open cylinder-head of the operating cylinder, and exhausting of the second pneumatic region by operation of said control-valve will correspondingly effect driving inward motion of the operating piston and the piston-rod toward the other or closed second cylinder-head for retracting purposes of the operating piston.

Claim 13

The combination of claim 10, wherein stop means for the operating piston is provided along the inner side wall of the operating cylinder.

Claim 14

The combination in a circuit-breaker of separable contacts separable to establish arcing, means biasing said separable contacts to the open-circuit position, a closing mechanism for effecting the closing of said separable contacts including a pneumatic operator, said pneumatic operator including a driving-piston operable within a pneumatic operating cylinder, a rotatable main lever pivotally mounted upon a stationary pivot, a piston-rod connected to said driving-piston and having a lost-motion mechanical connection with said rotatable main lever, said piston-rod projecting externally of said operating cylinder at one end thereof through a first open cylinder-head and having an effective cross-sectional area of ''''A'''', a first pneumatic region (76) defined by said driving-piston, the inner side-walls of the operating cylinder and said first open cylinder-head of the operating cylinder at said one end of the operating cylinder, a second pneumatic region (61) disposed on the other side of said operating piston from said first pneumatic region, high-pressure gas conditions existing in said first pneumatic region at all times during operation of the pneumatic operator, operating means including a three-way control-valve for alternately pressurizing or exhausting said second pneumatic region, the pressurization level of said second pneumatic region being substantially at the same gas-pressure level as said constant-pressure gas-level of the first pneumatic region, the cross-sectional area ''''A'''' of said piston-rod being of sufficient adequate cross-sectional area to rapidly retract by differential pressure-action the operating movement of the operating piston toward said one end of the operating cylinder, whereby pressurization of the second pneumatic region will operatively move the piston-rod toward said first open cylinder-head of the operating cylinder, and exhausting of the second pneumatic region by operation of said three-way control-valve will correspondingly effect inward driving motion of the operating piston and the piston rod toward the other or closed second cylinder-head for retracting purposes of the driving-piston, and said retracting movement of the driving-piston and said lost-motion connection will locate the piston-rod in a non-interfering position relevant to the rotatable main lever.

Claim 15

The combination in a circuit-breaker of separable contacts separable to establish arcing, means biasing said separable contacts to the open-circuit position, a closing mechanism for effecting the closing of said separable contacts including a pneumatic operator, said pneumatic operator including a driving-piston operable within a pneumatic operating cylinder, a rotatable main lever pivotally mounted upon a stationary pivot, a piston-rod connected to said driving-piston and having a lost-motion mechanical connection with said rotatable main lever, said piston-rod projecting externally of said operating cylinder at one end thereof through a first open cylinder-head and having an effective cross-sectional area of ''''A'''', a first pneumatic region (76) defined by said driving-piston, the inner side-walls of the operating cylinder and said first open cylinder-head of the operating cylinder at said one end of the operating cylinder, a second pneumatic region (61) disposed on the other side of said operating piston from said first pneumatic region, high-pressure gas conditions existing in said first pneumatic region at all times during operation of the pneumatic operator, operating means including a three-way control-valve for alternately pressurizing or exhausting said second pneumatic region, the pressurization level of said second pneumatic region being substantially at the same gas-pressure level as said constant-pressure gas-level of the first pneumatic region, the cross-sectional area ''''A'''' of said piston-rod being of sufficient adequate cross-sectional area to rapidly retract by differential pressure-action the operating movement of the operating piston toward said one end of the operating cylinder, whereby pressurization of the second pneumatic region will operatively move the piston-rod toward said first open cylinder-head of the operating cylinder, and exhausting of the second pneumatic region by operation of said three-way control-valve will correspondingly effect inward driving motion of the operating piston and the piston rod toward the other or closed second cylinder-head for retracting purposes of the driving-piston, and said retracting movement of the driving-piston and said lost-motion connection will locate the piston-rod in a non-interfering position relevant to the rotatable main lever.

Claim 16

The combination according to claim 12, wherein the valve means comprises a three-way pneumatic control valve, said rotatable main lever is releasably maintained in its closed position by a collapsible toggle-linkage, and said collapsible toggle-linkage is maintained in an underset condition by a releasable holding means.

Claim 17

The combination according to claim 12, wherein the valve means coomprises a three-way pneumatic control valve, said rotatable main lever is releasably maintained in its closed position by a collapsible toggle-linkage, and said collapsible toggle-linkage is maintained in an underset condition by a releasable holding means.

Claim 18

The combination according to claim 14, wherein the releasable holding means comprises a magnetically-actuated trigger-arm.

Claim 19

The combination according to claim 15, wherein a pair of shock-absorbers cushion the opening and closing motions of the rotatable main operating lever.