| 摘要 |
The present invention relates to a flat type dental handpiece using binding power of a ball, which significantly reduces the gap between the upper and lower portions of the handpiece without sacrificing binding power for a bur to allow the handpiece to move to the corner portions of the oral cavity of a patient. The present invention comprises: a housing having an installation space inside; an impeller installed to be rotatable inside the housing; a shaft which is installed at the center portion of the impeller to rotate along with the impeller and has an inclined surface having a wide upper portion and a narrow lower portion inside the shaft; a bearing installed to support the shaft individually at the upper portion and lower portion of the shaft; a ball holder which is installed at the inner portion of the shaft and has a plurality of thorough holes placed in the circumferential direction; a plurality of balls which are installed at thorough holes of the ball holder, declines simultaneously when the ball holder declines and comes in contact with the outer peripheral surface of a bur which penetrates vertically through the shaft to bind, as a wedge, the bur for the shaft, and unlocks the binding of the bur when the ball holder rises; and an elastic member which is installed at the upper side of the ball holder to prevent the ball holder from rising via elastic force and, if more than a predetermined force is applied, allow the ball holder to rise. |
