US 4,064,772 AGranted

Tubing wrench with air powered return

AssigneeCooper Industries, Inc.

InventorsH. Edward Boyd, Thomas M. Freiburger

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Abstract

The disclosure relates to a pneumatic tubing wrench wherein a radially slotted socket member is rotatably mounted in a housing end portion having a similar slot. When the slots of the socket and the housing are aligned, the socket may be placed over a length of tubing and engaged on a fastener. For realignment of the slots following tightening of a fastener and axial disengagement of the socket from the fastener, a spool type valve is provided near the throttle valve. When the throttle lever is depressed only slightly, the throttle valve is opened to admit a very small flow of air through the secondary exhaust flow path of the tool's air motor, thereby driving the motor in reverse. A spring-biased pin and inclined slot arrangement on a portion of the tool's gearing permits the motor to be driven backward only to the position wherein the socket and housing slots are aligned. When the throttle lever is fully depressed, the spool valve is shifted so that air at line pressure is admitted into the intake area of the motor to drive the motor in the forward direction.

Claims7

Dependent claims

In a power driven tubing wrench having an air motor, a throttle valve for selectively admitting and shutting off a flow of pressurized air to the air motor, a spool valve for controlling the direction of rotation of the air motor by selectively and alternately linking the inlet and exhaust sides of the air motor with pressurized air and the exterior of the tool, a housing extending forward from the air motor and including a forward end with a circular opening therethrough and a radial slot therein, a generally annular, radially slotted fastener driving socket member rotatably positioned within the forward end of the housing, a driving connection between the motor and the socket member, and means for stopping the reverse rotation of the socket member at a position wherein the radial slots of the forward housing end and of the socket member are in alignment, the improvement, comprising a unitary spool and throttle valve stem axially movable from a first position opening to admit air flow to the inlet side of said motor, to a second position to shut off the inlet side of said motor and admit air flow to the exhaust side of said motor and thence to a third position of no air flow.

Dependencies are inferred from the claim text.