| 摘要 |
Each of three jaws (15) of a rotary rock drilling chuck is carried by the stem (14) of a piston (13) acting in a cylinder (12) against belleville springs between it and an end cap (18). Hydraulic pressure can be applied to the opposite end of each piston to overcome the spring pressure and release the chuck. Three pairs of counterweights (20) are equally and circumferentially spaced abut the clamping axis and act through levers (21) pivoted to the chuck body at (22) so as to apply force to the respective pistons and thus to counteract centrifugal force acting on each piston. |
