Abstract: A control mechanism of revolving speed of an electric tool comprises a speed changing mechanism and a speed selecting device. The speed changing mechanism is composed of an action ring, a locating ring and two slide rods. The control of revolving speed of the electric tool is brought about easily and precisely by means of the speed changing mechanism in conjunction with the speed selecting device which is composed of a seat, a locating frame fastened to the main body of the electric tool, and a push button.

Abstract: An eccentric-motion motor for driving a utilization mechanism includes a stator defining a closed surface pathway, an armature composed of a permanent magnet rollably disposed on the closed surface pathway, a series of electromagnetic elements disposed in the stator along the closed surface pathway, circuitry for successively energizing the electromagnetic elements to cause them to attract and/or repel the armature so that it rolls along the closed surface pathway, and a coupler mechanism for coupling the armature to the utilization mechanism so that as the armature is caused to roll, the utilization mechanism is powered by the operation of the motor.

Abstract: A small motor having a two-pole permanent-magnet rotor and a U-shaped laminated stator having a pair of limbs with end portions that form magnetic poles for the rotor. The limbs carry alternately energized exciter coils including three nested winding layers arranged in two winding groups, of which the outer winding layer and the inner winding layer of the first limb and the second limb, respectively, and the central winding layer of the second limb and the first limb, respectively, are connected in series with one another.