Clamping jaw and chuck
A clamping jaw for a chuck includes a jaw body on which there is formed at least one jaw step having a step head, which has a sensor on its end face, for holding a clamping insert which is formed from a base leg and two fastening legs projecting from the base leg. On each of the opposite longitudinal sides of the step head there is formed a threaded bore for receiving a fastening screw whose screw head is received in a through-opening which is formed in the fastening leg of the clamping insert that is assigned to the longitudinal side, wherein, on each side, the longitudinal axes of the threaded bore and of the through-opening assigned thereto have an offset when the base leg bears against the end face. Also, a chuck has a chuck body, in which such clamping jaws are arranged in uniformly-distributed radial jaw guides.
1 . A clamping jaw for a chuck, the clamping jaw comprising:
a jaw body on which a jaw step is formed, which jaw step has a step head having a first longitudinal side, a second longitudinal side opposite the first longitudinal side, a front face disposed between the first longitudinal side and the second longitudinal side, a first threaded bore formed in the first longitudinal side, a second threaded bore formed in the second longitudinal side and a sensor disposed at the front face,
a clamping insert formed from a base leg, a first fastening leg projecting away from the base leg and a second fastening leg spaced apart from the first fastening leg and projecting away from the base leg, wherein a first passage opening is formed in the first fastening leg and a second passage opening is formed in the second fastening leg,
wherein the jaw step is configured to hold the clamping insert with the base leg of the clamping insert resting against the front face of the step head,
a first fastening screw having a first screw head held in the first passage opening formed in the first fastening leg of the clamping insert, which first fastening leg is adjacent to the first longitudinal side of the step head, and
a second fastening screw having a second screw head held in the second passage opening formed in the second fastening leg of the clamping insert, which second fastening leg is adjacent to the second longitudinal side of the step head,
wherein a first longitudinal axis of the first threaded bore is offset from a first longitudinal axis of the first passage opening and a second longitudinal axis of the second threaded bore is offset from a second longitudinal axis of the second passage opening, as a result of the base leg of the clamping insert resting against the front face of the step, to such an extent that no force is absorbed by the first screw head or the second screw head as a clamping force is applied.
2 . The clamping jaw according to claim 1 , wherein the first fastening screw and the second fastening screw are formed as cylinder screws and the first screw head and the second screw head are cylindrical screw heads.
3 . The clamping jaw according to claim 1 , wherein an undercut having a radius is formed below the step head on a base of the jaw step.
4 . The clamping jaw according to claim 3 , wherein a first groove is formed on the first longitudinal side of the step head between the front face and the first threaded bore and runs parallel to the front face, and
a second groove is formed on the second longitudinal side of the step head between the front face and the second threaded bore and runs parallel to the front face.
5 . The clamping jaw according to claim 1 , wherein the front face of the step head runs inclined at an angle relative to a longitudinal axis of the step head.
6 . The clamping jaw according to claim 5 , wherein the angle amounts to between 7° and 12°.
7 . The clamping jaw according to claim 5 , wherein a side of the base leg of the clamping insert that faces the front face runs at an incline with a clamping insert angle that is 0.20° to 0.50° smaller than the angle of the front face.
8 . The clamping jaw according to claim 1 , wherein the clamping insert requires turning to achieve a contour, the first fastening screw comprises a first countersunk screw the first passage opening has a first conical surface forming a first countersunk bore on an outside of the first passage opening, the second fastening screw comprises a second countersunk screw, and the second passage opening has a second conical surface forming a second countersunk bore on an outside of the second passage opening.
9 . The clamping jaw according to claim 8 , wherein a central longitudinal axis of the first conical surface is offset from a central longitudinal axis of the first threaded bore.
10 . The clamping jaw according to claim 1 , wherein a guide strip that is T-shaped in cross-section is formed on the jaw body, in which guide strip, a groove having a double recess is formed in every side.
11 . A chuck having a chuck body, in which clamping jaws according to claim 1 are arranged in radial jaw guides uniformly distributed over a circumference of the chuck body.