Torque control clutch for a power tool

A power tool comprising a fluid operated motor and rotary drive input drivingly connected to the motor, a rotary drive output, a frictional-contact clutch having rotary driving and driven clutch parts respectively connected in driving relation to the drive input and drive output for normally establishing a releasable unitary drive connection between the drive input and drive output and providing relative slipping movement therebetween at a predetermined output torque, a power drive control unit including a latch movable between operation and power shutoff positions, the latch in operating position being operable for establishing motor operation, the latch being axially movable relative to the driving clutch part between starting and operating positions, the latch being supported for rotary movement in synchronism with the drive clutch part and for pivotal movement in opposite angular directions relative to the driven clutch part, and a rotary actuator including a pin mounted in the driving clutch part and movable in an angular path of movement containing the latch, the actuator pin being supported in the driving clutch part for reciprocating axial movement in offset parallel relation to the rotational axis of the driving clutch part, the rotary actuator being operable responsive to relative slipping movement between the drive input and drive output at said predetermined output torque to move the latch from operating position to power shutoff position.

An air operated power tool comprising a housing having an air inlet connected to a source of compressed air, an air operated motor having a rotary drive output, an air supply passage between the source of compressed air and the motor, an inlet valve movable within the passage between opened and closed positions for controlling air flow to the motor, a rotary tool output, a friction clutch having a rotary driving clutch part connected to the air motor drive output and a rotary driven clutch part connected to the tool output normally establishing a unitary driving relation between the motor drive output and the tool output while providing relative rotary slipping movement between the driving and driven clutch parts at a predetermined output torque, a push rod drivingly connected to the inlet valve and movable axially within the housing between an operative position wherein the inlet valve is in opened position to establish air flow to the motor and a shutoff position wherein the inlet valve is in closed position interrupting air flow to the motor, a push rod latch pivotable about a pivot axis extending in parallel relation to the rotational axis of the rotary drive output, the latch being pivotable between an operating position, wherein the latch maintains the push rod in operative position, and a release position wherein the push rod is movable to shutoff position, and a latch actuator cooperating with the friction clutch for pivoting the latch from operating position into release position responsive to friction clutch slippage at said predetermined output torque to interrupt air flow to the rotary drive in less than a single revolution of relative rotation between the driving and driven clutch parts.

An air operated power tool comprising a housing having an air inlet connected to a source of compressed air, an air operated motor having a rotary drive output, an air supply passage between the source of compressed air and the motor, an inlet valve movable within the passage between opened and closed positions for controlling air flow to the motor, a drive spindle connected to a rotary tool output, a friction clutch having a rotary driving clutch part connected to the air motor drive output and a rotary driven clutch part drivingly connected to the drive spindle for synchronous rotation therewith normally establishing a unitary driving relation between the motor drive output and the tool output while providing relative rotary slipping movement between the driving and driven clutch parts at a predetermined output torque, the drive spindle being axially movable relative to the driven clutch part between an inoperative position and an operating position, a push rod drivingly connected to the inlet valve and movable axially within the housing between an operative position wherein the inlet valve is in opened position to establish air flow to the motor and a shutoff position wherein the inlet valve is in closed position interrupting air flow to the motor, a push rod latch movable between an operating position, wherein the latch maintains the push rod in operative position, and a release position wherein the push rod is movable to shutoff position, the latch being supported on the drive spindle for angular movement between said operating and release positions and for axial movement in synchronism with the drive spindle, and a latch actuator cooperating with the friction clutch for moving the latch from operating position into release position responsive to friction clutch slippage at said predetermined output torque to interrupt air flow to the rotary drive in less than a single revolution of relative rotation between the driving and driven clutch parts.