Abstract: A motor control circuit for disconnecting the motor's power supply when the motor is stalled but maintaining it connected when it is running comprising a power loop and control loop, the former including a signal sensing means which provides an output sensing signal whose magnitude is a function of the motor's state in series with an ON, OFF switching means' input-output terminals which is responsive to the magnitude of a control signal applied to its control terminal to control its state. The control loop comprises a counter which provides a control output signal in response to a predetermined count and whose input is fed by the output of a voltage controlled oscillator whose frequency is a function of the magnitude of the output sensing signal of the signal sensing means to which it is connected. A resetting means is coupled to the reset terminal of the counter for periodically resetting the counter. The output control signal from the counter is fed to the control terminal of the switching means.

Abstract: The manually-actuated, rotary-impact tool for rotatively driving a fastener has a spring in a handle for storage of energy, a rotatable tool head and an inertia member surrounding the tool head and connected to the handle via driving connections. A cam associated with the handle is provided to coact with the driving connections to disengage the driving connections when the tool head rotation is resisted by a predetermined force and the handle is rotated relative to the tool head and to allow re-engagement of the driving connections in another operative condition. A lever arm is pivotally connected to the handle so as to coact with the handle and inertia member to actuate the spring for storage of energy upon resistance of the tool head to rotation and to rotate the inertia member under the force of the stored energy of the spring and effect conversion of the kinetic energy of the inertia member to impact force on the tool head upon re-engagement of the driving connections.

Abstract: The actuator assembly is a unitary structure comprising a self-braking rotary power unit and a spring clutch mounted on a frame and interconnected so that the spring clutch transmits the rotary driving force of the power unit to a load to thereby effect its movement in one direction, the power unit and spring clutch co-acting when the power unit is inoperative to hold the load in a selected position. An electro-magnetic device coacts with the spring clutch to cause the spring to disengage and allow the load to move in a direction opposite of the one direction.

Abstract: The rotary impact mechanism has a plurality of helical springs disposed adjacent to the outer peripheral surface of a rotary inertia member which springs are anchored at one end to the inertia member and at the opposite end to a rotary driving input member so that upon relative rotative movement between the input and inertia members the springs are loaded and thereafter function to rotatively drive the inertia member. The inertia member carries at least one pawl which is capable of engagement and disengagement from a driven, toothed, output member, the pawl impacting against a tooth of the output member to drive the latter when the inertia member is rotatively driven by the springs.

Abstract: In a rotary impact mechanism which has input, output and inertia members substantially symmetrical and journaled about each other for independent angular movement about a common axis and a pawl and ratchet assembly for interconnecting the input and output members for torque transmission, the pawl spring assembly for biasing the pawl in a direction to engage the ratchet comprises a plurality of spring elements formed into a unitary structure and arranged with respect to the pawl to sequentially engage and load the pawl as the pawl is moved in a direction to disengage from the ratchet.