Patent ID: 6969056

Claim:
A clamping device in which at least a first clamping arm is driven and rotated to clamp a workpiece between a second clamping arm and the first clamping arm, the device comprising: an arm rotary shaft rotatably supported on a clamp body and mounted with the first clamping arm; a clamp arm driving mechanism including a worm wheel mounted to the arm rotary shaft, a worm engaged with the worm wheel, and a first driving source for driving the worm; a junction frame supporting the worm and the first driving source for turning around the arm rotary shaft independently of the arm rotary shaft; a clamping force applying mechanism for applying a rotating force in a direction opposite to a reaction force in clamping to the junction frame to thereby generate a rotating force in a clamping direction in the arm rotary shaft through the worm and the worm wheel engaged with each other to thereby apply a clamping force to the first clamping arm; and a sensor for outputting a signal when the sensor detects that the first clamping arm has come in contact with the workpiece to stop the first driving source and to cause the clamping force applying mechanism to operate.