Clamping device with force amplifier, especially machine vise

In a clamping device with force amplifier with a clamping device body, a fixed jaw arranged thereon and a jaw movable relative thereto, for the adjustment of which there is provided a rod acted upon by the force amplifier, with a rotatable tightening sleeve surrounding the force amplifier and having an external thread, engaging thereby in a female thread of a stationary housing surrounding the tightening sleeve, the rotational movement of which is delimited relative to the housing by stop surfaces, with a first tightening ring arranged fast against rotation in the tightening sleeve, with a second tightening ring arranged for limited rotation in the tightening sleeve and rotatable by means of an operating lever attached to said rod, with a plurality of tightening pins arranged between the tightening rings, which pins are arranged in one end position (open position) of the second tightening ring at an acute angle to the tightening sleeve axis and in the other end position (clamping position) of the second tightening ring, approximately parallel to the tightening sleeve axis, with a compression spring acting between the first and second tightening rings, the improvement wherein said clamping device includes a thrust bearing as well as a plurality of Belleville springs mounted on said rod proximate a hand grip, the pre-tension of said Belleville springs can be adjusted by an adjusting sleeve and further tightened by means of the force amplifier to act on the rod when in the clamping position of the second tightening ring, wherein the stationary housing is arranged in the clamping device body beneath the fixed jaw, and wherein the second tightening ring is fixedly connected to a first end of said rod extending through said tightening ring and the movable jaw to a second end of said rod which is connected to said adjusting sleeve and the operating lever, wherein said Belleville springs are arranged and bear with interposition of said thrust bearing on a side of the movable jaw facing away from the fixed jaw, and wherein said rod is surrounded by a hollow threaded spindle, rotatable by means of said hand grip, wherein said spindle can screw into the movable jaw to move said movable jaw.