Power operated lathe chuck - with linear motion of piston changed to rotation by bush with helical splines

摘要

The jaws (4) of the power operated chuck (1) are keyd to the segments (3) which slide in radial grooves (6) in the chuck body (2). The segments (3) are provided with teeth (13) forming spiral grooves. These teeth (13) mesh with teeth projecting from the blocks (11) which are fitted in the bore (12) of the body (2). The blocks (11) have teeth (14) on their inner faces which mesh with teeth (22) on the driving ring (21). The driving ring (21) is provided with axial splines which engage helical splines (25) on the shaft (24). The shaft (24) is attached to the piston rod of a pressure actuated jack. Axial movement of the jack thus causes rotation of the ring (21) and blocks (11) which, in turn, imparts a radial motion to the chuck jaws (4).