| 摘要 |
A self-tightening drill chuck has a chuck body adapted to be mounted on a drill spindle for rotation about an axis and formed with substantially cylindrical front and a rear outer surfaces both centered on the axis and axially offset from each other and with an outwardly open groove between the front and rear surfaces. A tightening sleeve surrounding the body is formed with substantially cylindrical front and rear inner surfaces both centered on the axis and riding on the front and rear surfaces of the body and with an inwardly open groove between the front and rear inner surfaces and forming with the groove of the body an annular generally circular-section passage This sleeve also is unitarily formed with a rearwardly flared substantially frustoconical seat also centered on the axis. Rollers riding in the grooves support the sleeve on the body so as to permit relative rotation of the body and sleeve about the axis while preventing relative axial displacement. A jaw guide in the sleeve is formed with a plurality of axially forwardly open and angularly spaced slots carrying respective jaws axially and radially displaceable in the slots and on the seat. A spring unit braced axially between the guide and the chuck body urges the guide axially forward and presses the jaws axially forward against the seat. |
