摘要 |
A lathe chuck has a chuck body rotatable about a chuck axis and formed with a plurality of angularly spaced and radially extending inner guides receiving respective inner jaw parts and with a plurality of angularly spaced and radially extending outer guides receiving respective outer jaw parts. The inner jaw parts can be synchronously radially moved to open and close the chuck. Respective coupling members are provided between the inner jaw parts and the respective outer jaw parts and are rotational about respective coupler axes extending radially of the chuck axis between coupling positions engaging both of the respective parts and coupling same together for joint radial displacement and angularly offset decoupling positions permitting relative radial displacement of the respective parts. Locking elements are operatively engageable between the inner jaw parts and the chuck parts for blocking radial displacement of the inner jaw parts except when the respective coupling members are in the coupling positions. Thus unless all of the coupling members are in the coupling position the operator cannot close the chuck and start up the lathe. |