摘要 |
A chuck especially for a machine tool that operates in a universal manner as a two, three or four jaw chuck. The chuck (10) comprises four jaws (25) arranged in diametrically opposed pairs on the front face (12) of the chuck (10). The chuck (10) including drive pinions (36, 37) that drive a scroll (39, 239) that co-axially carries a differential gear train including a pair of differential gears (50, 51) one driving one pair of jaws (25) and the other driving the other pair whereby the differential gear train apportions the drive between the pair of jaws so that one pair may move independently of the other pair. |