Machine spindle having a gas spring-operated tool-clamping mechanism

A machine spindle comprising:

• a casing defining a center axis;
• and
• a clamping mechanism disposed in the casing, the clamping mechanism comprising:
• a front drawbar having axially spaced front and rear ends, the front end carrying a tool clamp operable to clamp a tool in response to rearward movement of the front drawbar,
• a rear drawbar arranged behind the front drawbar;
• a force transmitting mechanism for transmitting rearward motion of the rear drawbar to the front drawbar for movement of the front drawbar rearwardly, wherein the force-transmitting mechanism comprises a force-amplifier wedge arrangement;
• a gas spring for biasing the rear drawbar rearwardly comprising:
• a housing disposed in the casing and defining a gas chamber having a front wall disposed behind the wedge arrangement and through which the rear drawbar extends, and
• a piston disposed in the gas chamber for axial movement therein and releasably connected to a rear end of the rear drawbar by a releasable coupling disposed in the chamber.