| 摘要 |
A drill chuck has a chuck body rotatable about a chuck axis and formed with a radially open threaded bore and with a radially open unthreaded bore. A plurality of jaws are radially displaceable on the chuck body. A tightening ring is rotatable on the body about the axis thereof and is connected via screwthread formations with the jaws to displace same radially inwardly when the ring is rotated in a tightening direction and to displace them radially outwardly when rotated in an opposite loosening direction. A screw threaded in the threaded bore is screwable therein in one direction for radial inward displacement and in the opposite direction for radial outward displacement into engagement with the ring. Thus the screw can be screwed out to engage the ring and block its rotation. This screw is formed with a radially outwardly open recess into which the end of the handle of a chuck key can fit. Otherwise this key can fit in the normal manner into the unthreaded bore of the chuck body to engage teeth formed on the tightening ring to open and close the chuck. |
