A power tool includes a motor and a motor switch movable between on and off settings. A transmission connects the motor to the tool holder of the power tool. The transmission includes a torque-responsive clutch arrangement which transmits torque below a preselected value in a first manner and torque above the preselected value in a different and distinguishable second manner. The torque-responsive clutch means undergoes an automatic change of torque transmission manner in response to a rise of t...

A power swivel particularly adapted for downhole cementing operations. The power swivel includes a housing having a fluid passageway therethrough and a stem assembly mounted for rotational movement with respect to the housing and having a fluid passageway communicating with the housing passageway. A hollow bore motor mounted with the housing receives the stem assembly through a central bore of the motor and rotates the stem assembly with respect to the housing.

A directional valve assembly for use in hydraulic power systems such as are used on fork lift trucks has a plurality of sliding spool directional valves and a balanced relief valve mounted in the body formed of a plurality of sections bolted and gasketed together. The main lift section has a load-holding check valve of special design together with means on the spool for opening the check valve to lower the load. Means are provided in the assembly for preventing interflow from one valve spool to ...

A power wrench opens and closes a gate valve on irrigation water pipe thereby controlling water flow from the pipe into desired areas for irrigation of crops. The power wrench includes a tubular flow member which defines a flow passage extending through a second gear and through a gripping member mounted on the second gear and engageable with the gate valve whereby water flowing from the open valve will flow through the gripping member and tubular flow member. The power wrench is power operated ...

A power supply for providing two different DC voltages from a transformer having a center tapped secondary winding is disclosed. An arrangement of diodes and capacitators forming a voltage doubler is connected to the secondary winding to provide a low DC voltage from the center tap approximately equal to one half of the RMS voltage across the secondary winding, and a higher DC voltage greater than twice the RMS value of the AC voltage across the secondary winding of the transformer.

An internal combustion two stroke engine is provided having at least one cylinder within which a piston reciprocates. The engine is joined to a gear box which includes a ring gear. A pair of gears having diameters half that of the ring gear move within the latter. At least one of said pair of gears is connected to a piston by a pin extending between the piston and the periphery of said gear. An additional pair of gears are fixed to respective ones of the first-mentioned gear pair and are operati...

A power wrench having at least a partially annular drive head connected at first and second pivots through a first of a pair of telescopic members and to a third member, respectively, the third member being connected by a third pivot to the second member, and upon a relative linear telescopic motion of the first and second members, the drive head is rotated through a predetermined arc under the control of the third member.

A two-contact power connector made up of identical halves, each half having a base member and a pair of tubes, a large tube and a small tube, extending forwardly therefrom, with the small tube on each half telescoped in the large tube on the other half when the halves are connected. The contacts in the two halves are enshrouded by the telescoped tubes when the connector halves are connected, preventing accidental grounding. The contacts are releasably held by collet type retention members. Integ...

Power capacitor with minimal self-inductance includes a stack of metal layers mutually superimposed perpendicularly to a given axis, with respective layers of insulation disposed between mutually adjacent metal layers of the stack, the metal layers and the insulation layers being formed with mutually aligned cut-outs in vicinity of the given axis so as to form a free space within the stack, respective surface portions of alternating layers of the metal layers projecting into the free space above...

In order to eliminate distortion a power amplifier is biased to Class-A or Class-B operation and in order to minimize the power loss the supply voltage of a power source is decreased as much as possible and the power source is driven by another highly efficient power amplifier so as to follow an output voltage.