Abstract: Each of master jaws (17) has a middle spherical part guided for sliding movement by a spherical guide surface (16) formed in a chuck body (2), a round back end part (19) extended slidably through a spherical bearing member (12) supported on a support member (10) attached to a middle part of a driving member (5). Each master jaw (17) is provided with a through hole (26) extending between the front and the back end thereof and a sliding member (30) is inserted in the through hole of the master jaw (17) through the front end of the same so as to come into sliding contact with a stopper (36) attached to a chuck body (2). Therefore, the state of sliding contact between the sliding member (30) and the stopper (36) can be adjusted on the side of the front part of the chuck and work for adjusting the state of sliding contact can be easily achieved.

Abstract: Each of master jaws (17) has a middle spherical part guided for sliding movement by a spherical guide surface (16) formed in a chuck body (2), a round back end part (19) extended slidably through a spherical bearing member (12) supported on a support member (10) attached to a middle part of a driving member (5). Each master jaw (17) is provided with a through hole (26) extending between the front and the back end thereof and a sliding member (30) is inserted in the through hole of the master jaw (17) through the front end of the same so as to come into sliding contact with a stopper (36) attached to a chuck body (2). Therefore, the state of sliding contact between the sliding member (30) and the stopper (36) can be adjusted on the side of the front part of the chuck and work for adjusting the state of sliding contact can be easily achieved.

Abstract: A finger chuck for use with a machine tool comprises a chuck main body having a front wall and a rear wall, the front wall and the rear wall defining a space therebetween. A centering device is supported by the front wall for centering the workpiece on the axis of the chuck main body. Jaws are supported by the front wall for holding the workpiece. A rearwardly protruding portion is provided on the front wall toward the rear wall within the space, and a cavity is defined in the protruding portion so as to open in the front surface of the front wall, the cavity accommodating at least part of the centering device. A drawing member extends through the rear wall in the axial direction, and is shifted by a drive source in the axial direction. A guide portion is disposed in the space integrally with the drawing member, so as to be guided on the protruding portion in the axial direction. A seat surface is formed around the guide portion, and a spider is supported on the seat surface for movement therealong.