BigPatents India

A vise includes a first block and a second block received in a sleeve in the body of the vise. A threaded rod is connected to the second block and an adjusting rod is connected to the first block. A driving shaft is connected to the adjusting rod and has an action head with two inclined surfaces. Two pivotable members are connected between the two blocks and each include a clamp rod which sandwich the action head there between. The sleeve has a pin with a notch and the adjusting rod includes a bead and spring received therein, the bead engaged with the notch. When a force is applied to the adjusting rod and larger than the force that the bead is engaged with notch, the pin is disengaged from the keyway and the action rod can be pushed and the inclined surfaces push the pivotable members to move the first block by a large force to clamp the object.