Abstract: An electrical switch actuated by a longitudinally reciprocable electrical contact carrier, with such reciprocation being brought about by a two-piece rocker actuator with one of the actuator pieces comprising a removable locking key which when removed from the actuator assembly prevents movement of the contact carrier and thus prevents actuation of the switch.

Abstract: A portable electric motor-driven tool including an electric motor and an electrical control system for controlling the speed of the motor. The control system includes an electric switch for controlling the flow of electrical current to the motor and a composite thyristor and heat sink assembly, with electrical current conducting wires connecting the switch with the assembly. The motor has a fan providing an air stream for cooling the motor. The motor housing has a cavity disposed in the airstream and is configured to receive the thyristor and heat sink assembly and its electrical current conducting wires in quickly detachable relation therein. The heat sink includes an elongated base having laterally extending heat dispersing vanes of various sizes with each vane having a wing portion extending laterally from the vane for added heat dispersement.

Abstract: A manually operable releasing mechanism for plug in-type terminals that are used for rapidly connecting electrical conducting lines to an electrical unit, and providing for rapid deactuation of the retainer for the conducting line to permit ready withdrawal of the conductor line from the unit, when so desired.

Abstract: A trigger-lock control for a motor switch of a power tool is presented including a trigger attached to a rigidly connected elongated slide portion which reciprocates in a housing containing switch components arranged longitudinally in a "power-on" and "power-off" arrangement so that the slide portion can selectively operate these contacts when it is reciprocated by motion of the trigger. A spring urges the trigger and slide portion normally to a power-off position and locking means is provided to lock the elongated slide portion in the power-off position by providing an oscillating lever having a downwardly extending point at its free end which enters into an upwardly opening recess in the upper wall of the slide portion when the parts are in the power-off position. The lever is pivoted on a horizontal pivot on the top of the housing and joined to the lever is either a thumb piece or a lever adapted to be easily operated by a hand of the operator holding the tool.