Abstract: A detachable coupling consisting of two mating halves which when detachably interconnected form a ring which is free to rotate but is restrained axially with respect to elements to be connected.

Abstract: A cartridge, on which is mounted two active carbon brush assemblies, plugs into a specially designed opening in one side of a motor housing of a power operated tool. As the cartridge is inserted or removed, electric terminals mounted on the cartridge connect with or disconnect from terminals fixed on the motor housing to automatically establish or disconnect the electrical connections for controlling the motor operation. A single non-metallic screw holds the cartridge with both active brush assemblies in operative position within the opening with the active carbon brushes in juxtaposition and engageable with the commutator of the motor at diametrically opposed positions. The opening in the motor housing has an integral support therein. Such support also provides ramps to guide the carbon brushes up and onto diametrically opposite sides of the motor's commutator as the cartridge is plugged into the opening.

Abstract: A portable electric tool has an ON-OFF trigger operated switch and a locking member to hold the trigger with the switch in ON position. The trigger has one end pivoted in the handle of the tool. A portion of the trigger extends outwardly from an opening in the handle so that it can be manually moved inwardly to ON position by the operator while holding the tool by its handle. Such inward movement is resiliently resisted and the ON position is momentary so that when the operator releases actuating pressure, the trigger automatically moves to switch OFF position.