Abstract: The present dental handpiece generally comprises a handle portion, a powerhead assembly integrally and perpendicularly linked to the handle portion, a bushing integrally inserted into the handle portion, a rotating driving shaft journaled for rotation by means of a sleeve in the bushing, the rotating driving shaft having an integral circular disc at its top end portion, the circular disc carrying around its periphery a pinion lug which is parallel to both the disc and the rotating driving shaft, a hollow cylinder kept in motion inside the powerhead assembly at its top end held by a bushing and at its lower end by a bushing cap respectively, the rotating driving shaft having an arc-shaped longitudinal slot, a roller bearing slidably inserted into the slot and the pinion lug being slidably inserted into the central horizontal opening of the roller bearing to couple the rotating driving shaft to the rotating driven shaft whereby a drilling tool is driven to rotate in one direction and in the opposite direction a

Abstract: A device of this invention for opening and closing a chuck for a dental handpiece comprises a housing and an output shaft rotatably journalled in the housing. A cylindrical hollow is formed axially from a top end portion into the output shaft and a plurality of openings are formed at equally spaced portions around said shaft near an innermost portion of the hollow. A truncated cone-shaped column having a conical surface is firmly inserted into the innermost hollow of the output shaft to define a space for a small metallic driving ball. The small driving ball is rotatably inserted into each opening of said output shaft, and a large metallic driven ball is rotatably inserted into the hollow to abut against these small driving balls. A ball control sleeve having a tapering inner periphery is slidably fitted on the output shaft to locate at the openings.

Abstract: A dental handpiece of the present invention is provided with a head extending at substantially a right angle to said handpiece having a hollow therein. The head is also provided with a hollow vertically communicating with the hollow of the handpiece. A semispherical groove is cut into the hollow wall longitudinally and partially adjacent an orifice of the head. A cartridge having an elongated opening cut through at a mid-portion of a bottom thereof and also a small opening at a top wall near a lower orifice and at the same position as the semispherical groove is mounted into its hollow with a rotatable bushing through metal bearings inserted into a lower and upper orifices of the hollow. A gear is secured to the bushing at a position to form an entry into the elongated opening of the cartridge. Together with the spherical groove of the head and the small opening of the cartridge, a semispherical cavity cut into the lower metal bearing defines a spherical space for a metal ball.