PIEZOELECTRIC NEEDLE SELECTOR IN A CIRCULAR KNITTING MACHINE

A piezoelectric needle selector utilizes an upstanding knitting cylinder having a multiplicity of needle jacks mounted thereto for independent movement in a direction parallel to the axis of the knitting cylinder. A plurality of piezoelectric actuators, each having a stack of planar piezoelectric elements coupled at one end to a plunger, are mounted via respective holders to a fixed support frame disposed adjacent the knitting cylinder. The selective application of voltage pulses to the piezoelectric actuators results in the linear travel of the associated plungers toward and away from the knitting cylinder. The linear travel of the selected plungers is translated into the movement of the desired needle jacks up and down on the knitting cylinder, as by several needle select levers pivoted by the plungers and acting on the usual butts on the needle jacks.