Abstract: A positioning device having a chamber having a chamber exhaust valve in a first end and a chamber fluid inlet in a second end; a piston disposed in a chamber between the first end and the second end, the piston being slidable in the valve chamber between a first position toward the first end and a second position toward the second end; the fluid communication opening having a smaller cross-section area than the chamber exhaust valve; and a piston biasing spring urging the piston toward the chamber second end and away from the chamber first end, the piston biasing spring responsive to a fluid pressure differential between the first and second chamber ends above and below a predetermined level to move the piston into the first and second positions, respectively.

Abstract: A tool is provided with an output extension head having parallel sets of drive trains drivingly connecting an input drive gear and an output socket gear. The drive trains each have individual idler gears in mesh with both the input drive gear and output socket gear to significantly increase the ultimate torque capacity of the tool without increasing the thickness of the gear components or the radial dimensioning of the output end of the extension head.