Circuit interrupter having improved operating mechanism

A circuit breaker having an electrical contact movable between open and closed positions, a closing spring, charging means for charging the closing spring including a charging crank, an electric motor, a ratchet wheel, means for translating rotation of the electric motor to rotation of the ratchet wheel, and a ratchet shaft, with said ratchet wheel being mounted on said ratchet shaft such that rotation of the ratchet wheel rotates the ratchet shaft, discharge means for discharging the closing spring, and translating means for moving the electrical contact from the open position to the closed position in response to the discharge of the closing spring, characterized by:

• a charging cam on the ratchet shaft which rotates with the ratchet shaft and engages the charging crank during a predetermined angular rotation of the charging cam, to rotate the charging crank and charge the closing spring,
• and hook means which receives and supports the closing spring after the closing spring is charged by the charging crank, said ratchet wheel being mounted on said ratchet shaft to provide a predetermined relative rotational movement between the ratchet shaft and ratchet wheel before engagement,
• whereby shock forces which may be applied to the charging cam by the charging crank as the charging spring is transferred from the charging crank to the hook means are divided between the charging cam and ratchet wheel, being first applied to the charging cam and ratchet shaft, and then after said predetermined rotational movement of the ratchet shaft, to the ratchet wheel.

A circuit breaker having an electrical contact movable between open and closed positions, a closing spring, charging means for charging the closing spring including an electric motor, a ratchet wheel, a ratchet shaft, mechanical oscillator means for translating rotation of the electric motor to rotation of the ratchet wheel, and means for translating rotation of the ratchet wheel to charging of the closing spring, discharge means for discharging the closing spring, and translating means for moving the electrical contact from the open position to the closed position in response to the discharge of the closing spring, characterized by:

• said mechanical oscillator means including an eccentric mounted for rotation by the electric motor, a shaft mounted off-center on the eccentric, with said shaft having first and second surfaces, first and second levers mounted for independent rotation on the ratchet shaft, means for causing said first and second levers to move together, a pawl mounted for rotation on the first lever, means biasing said pawl against the ratchet wheel, said first and second levers each having a predetermined surface which is contacted by the first and second surfaces, respectively, of the shaft mounted on the eccentric, during each revolution of the eccentric,
• whereby movement of the first surface against the predetermined surface of the first lever moves the first and second levers and the first pawl from a first position to a second position, to advance the ratchet wheel, and movement of the second surface against the predetermined surface of the second lever moves the first and second levers and first pawl back to the first position.

A method of operating a circuit breaker having an operating mechanism which includes a closing spring assembly comprising a closing spring and first and second spring brackets, charging means for charging the closing spring, and discharge means for discharging the closing spring to close electrical contacts of the circuit breaker, characterized by the steps of:

• holding the first spring bracket,
• charging the closing spring by the step of moving the second spring bracket,
• holding the second spring bracket following the charging step,
• discharging the closing spring by the step of releasing the first spring bracket, to close the electrical contacts of the circuit breaker,
• releasing the second spring bracket following the step of discharging the closing spring,
• moving the completely released closing spring assembly as an integral assembly to a reset position,
• and repeating the steps of holding the first spring bracket, charging the closing spring, and holding the second spring bracket, to enable the circuit breaker to be closed, when desired, immediately following a trip of the circuit breaker.