Power tool control

Claim 2

In combination with a power tool having a stationary part, a rotary part and a motor for rotating said rotary part relative to said stationary part, including means for supplying power to said motor and a switch for terminating application of said power, the improvement comprising: means for actuating said switch after a predetermined amount of rotation of said rotary part following a substantial and sudden increase in force applied, comprising first means for measuring the amplitude of force being applied by said motor comprising clutch means having a shaft with a rotatable member attached thereto, and means for displacing said shaft longitudinally, and means for biasing said clutch means to a disengaged state unless said amplitude of force exceeds a predetermined amount, second means for measuring the amount of rotation of said rotary part commencing with a predetermined amplitude of said force being applied by said motor, comprising means actuated by said clutch means when engaged, including means actuated by said rotatable member when said shaft is displaced for actuating said switch.

Claim 3

The invention according to claim 1, wherein said shaft-displacing means is a diaphragm, said biasing means is a spring, and said means actuated by said rotatable member comprises a rotor attached to said shaft for contacting said rotatable member, and a radial arm extending from said shaft for actuating said switch.

Claim 4

The invention according to claim 2, further including a return spring for said shaft to bias it into a starting rotary position, and means for adjusting said starting rotary position.

Claim 5

In combination with a power wrench having a stationary part, a rotary part, and power means for driving said rotary part in rotation relative to said stationary part, means for tightening a shoulder butt joint a predetermined fixed amount, comprising switch means for releasing application of said power means, means for driving said rotary part until said shoulder butt joint has made contact, a rotor adapted for being coupled and uncoupled with said rotary part, a plunger for actuating said rotor from uncoupled to coupled position, means for biasing said plunger to uncouple said rotor until said butt joint contact, and an arm actuated by said rotor for contacting said switch after a predetermined amount of rotation of said rotary part.

Claim 6

In combination with a power wrench having a stationary part, a rotary part, and power means for driving said rotary part in rotation relative to said stationary part, means for tightening a shoulder butt joint a predetermined fixed amount, comprising switch means for releasing application of said power means, means for driving said rotary part until said shoulder butt joint has made contact, a rotor adapted for being coupled and uncoupled with said rotary part, a plunger for actuating said rotor from uncoupled to coupled position, means for biasing said plunger to uncouple said rotor until said butt joint contact, and an arm actuated by said rotor for contacting said switch after a predetermined amount of rotation of said rotary part.

Claim 7

The invention according to claim 4, wherein said switch-actuating means further comprises a spring for returning said arm to a starting position, and means for setting said starting position for adjusting the amount of rotation of said rotary part.

Claim 8

In combination with a fluid motor powered rotary tool having a rotating part and a stationary part, means for automatically driving said rotating part for a predetermined degree of rotation after a predetermined amplitude of force has been reacted, comprising in combination a switch for shutting off said fluid motor, said switch having an actuator therefor, a shaft having an enlarged rotor on one end thereof and being shiftable longitudinally for placing said rotor into contact with said tool-rotating part, a diaphragm attached to the other end of said shaft for shifting same when fluid pressure is applied, a spring for urging said shaft against the force applied by said diaphragm, said spring having sufficient strength to permit preliminary rotation of said tool-rotating part without shifting said shaft, a radial arm carried by said shaft and adapted for contacting said switch actuator after a predetermined degree of rotation of said shaft when shifted so that said rotor is in contact with said tool-rotating part, a return spring for biasing said shaft in rotation to a starting position prior to said rotation when the rotor is in contact with said tool-rotating part, and means for adjusting said starting position in order to predetermine the degree of rotation of said power tool after said amplitude of force has been reacted.

Claim 9

In combination with a fluid motor powered rotary tool having a rotating part and a stationary part, means for automatically driving said rotating part for a predetermined degree of rotation after a predetermined amplitude of force has been reacted, comprising in combination a switch for shutting off said fluid motor, said switch having an actuator therefor, a shaft having an enlarged rotor on one end thereof and being shiftable longitudinally for placing said rotor into contact with said tool-rotating part, a diaphragm attached to the other end of said shaft for shifting same when fluid pressure is applied, a spring for urging said shaft against the force applied by said diaphragm, said spring having sufficient strength to permit preliminary rotation of said tool-rotating part without shifting said shaft, a radial arm carried by said shaft and adapted for contacting said switch actuator after a predetermined degree of rotation of said shaft when shifted so that said rotor is in contact with said tool-rotating part, a return spring for biasing said shaft in rotation to a starting position prior to said rotation when the rotor is in contact with said tool-rotating part, and means for adjusting said starting position in order to predetermine the degree of rotation of said power tool after said amplitude of force has been reacted.