Abstract: A machine tool clamping device for releasably holding a tool holder having a tapered shank and a knob protruding from the tapered shank, the clamping device having: a spindle, rotatable about an axis, and having a tapered socket at a lower end thereof and an axial passage, the tapered socket being complementary in shape to the shank of a tool holder. Clamping members are pinned to the spindle and extend into the axial passage, the clamping members being pivotal between a clamped position in which the clamping members clamp the tool holder knob, and an unclamped position in which the clamping members release the tool holder knob. A drawbar is slidable within the spindle axial passage between the clamping members, the drawbar having a surface that acts to pivot the clamping members between the clamped and unclamped positions depending on the position of the drawbar within the axial passage. A spring is arranged between the drawbar and the spindle to bias the drawbar to the clamped position.

Abstract: A machine tool clamping device for releasably holding a tool holder having a tapered shank and a knob protruding from the tapered shank, the clamping device having: a spindle, rotatable about an axis, and having a tapered socket at a lower end thereof and an axial passage, the tapered socket being complementary in shape to the shank of a tool holder. Clamping members are pinned to the spindle and extend into the axial passage, the clamping members being pivotal between a clamped position in which the clamping members clamp the tool holder knob, and an unclamped position in which the clamping members release the tool holder knob. A drawbar is slidable within the spindle axial passage between the clamping members, the drawbar having a surface that acts to pivot the clamping members between the clamped and unclamped positions depending on the position of the drawbar within the axial passage. A spring is arranged between the drawbar and the spindle to bias the drawbar to the clamped position.