Abstract: Electric tool knob control apparatus comprises a compressing spring and a cam controller, which are set consequently on the sleeve of drive shaft base. Compressing spring is set between cam controller and base. On the sleeve, an external gearwheel is installed. Cam controller includes a spur cam-disk and a passive cam-disk. On spur cam-disk and passive cam-disk, a cam-disk flange and a cam-disk recess are circularly arranged and oppositely set up; therefore, cam-disk flange and cam-disk recess may engage to each other. On spur cam-disk, a plurality of planet gearwheel is set pivotally. By covering the outside of cam controller and sleeve with a knob with inward gear set inside diameter, planet gear wheel may engage with inward gear and external gear wheel in the same time. Also, passive cam-disk, which engages with knob, may rotate with knob and move in axial direction of knob. Passive cam-disk and spur cam-disk may be driven to rotate while knob is moved to rotate.

Abstract: A locking and slowing down device includes a central hole and a recess part, which are connected with each other. The central hole is inserted with an output shaft so that the spline shaft at one end of the output shaft extends into the recess part. The locking and slowing down device also includes an eccentric wheel set composed of a first eccentric wheel and a second eccentric wheel, which are connected with a first gear and a second gear, respectively, to move in opposite direction. The first gear and the second gear have a plurality of first through holes around a circle and second through holes around a circle, respectively. The protruding columns on the rotating plate penetrate through the first through holes and the second through holes, and each protruding column has an outer diameter smaller than the inner diameters of the first through holes and the second through holes. The first gear, the second gear, and the eccentric wheel set are placed within the recess part of the housing base.