Clamping device for machine tools

A clamping device for a machine tool, comprising:

• a movable carriage movably mounted on a fixed bed and clamped to a specified position on the fixed bed;
• a stationary fitting member fixed to the fixed bed and extending in a direction of movement of the movable carriage, the stationary fitting member having a wedge surface tilted downwardly;
• a movable fitting member provided on the movable carriage, the movable fitting member being movable between an extended position and a retracted position in the direction transverse to the direction of movement of the movable carriage, the movable fitting member further having a wedge surface complementary to the wedge surface of the stationary fitting member;
• a driving mechanism for moving the movable fitting member between an extended position where the movable fitting member engages the stationary fitting member to clamp the movable carriage to the fixed bed and a retracted position where the movable fitting member is disengaged from the stationary fitting member to release the movable carriage;
• and
• a backup member provided at the bottom of the movable carriage for contacting a front side face of the movable fitting member which is on an opposite side of the movable fitting member from the wedge surface.

A machine tool comprising:

• a fixed bed having a mounting surface and a recessed portion in which a ball screw for moving a movable carriage is disposed, wherein the movable carriage is movably disposed on the mounting surface by a means for mounting the movable carriage to the mounting surface;
• a stationary fitting member fixed to the fixed bed and extending in a direction of movement of the movable carriage, the stationary fitting member being fixed to the fixed bed at a shoulder of the recessed portion of the fixed bed and having a wedge surface;
• a movable fitting member provided on the movable carriage, the movable fitting member being movable in a direction substantially perpendicular to the mounting surface of said fixed bed, the movable fitting member further having a wedge surface extending parallel to the wedge surface of said stationary fitting member;
• and
• a driving mechanism having a longitudinal axis for moving the movable fitting member between an extended position where the movable fitting member engages the stationary fitting member to clamp the movable carriage to the fixed bed and a retracted position where the movable fitting member is disengaged from the stationary fitting member to release the movable carriage, wherein the movable fitting member is disposed such that the wedge surface of the movable fitting member is disposed to form an acute angle with the longitudinal- axis of the driving mechanism;
• and
• a backup member provided at the bottom of the movable carriage for contacting a front side face of the movable fitting member which is on an opposite side of the movable fitting member from the wedge surface.