Pattern jack actuator means for circular knitting machines

Claim 1

In a circular knitting machine including a needle cylinder supported for rotation about a vertical axis, needles supported for vertical movement in said needle cylinder, a pattern jack positioned beneath each of said needles, a plurality of knitting stations spaced around said needle cylinder, and cam means positioned in advance of at least certain of said knitting stations and being selectively engageable by said pattern jacks for raising the corresponding needles, said pattern jacks being movable between a first operative position where they engage and are raised by said cam means and a second inoperative position where they are not raised by said cam means, the combination therewith of improved pattern jack actuator means comprising: a. a plurality of closely spaced vertically aligned selector devices positioned in advance of each of said cam means at the corresponding knitting station, each selector device including 1. a control shaft supported perpendicular to the axis of rotation of said needle cylinder, said control shaft having an outer end portion supported for limited rotational reciprocation and having an inner end positioned closely adjacent the outer periphery of said needle cylinder, 2. a pattern lever fixed at one end to the inner end of said control shaft and extending at a right angle therefrom, the other end of said pattern lever including a cam surface for aligning with pattern butts at a certain level on said pattern jacks when said control shaft is recIprocated in one direction and for moving out of alignment with said pattern butts when said control shaft is reciprocated in the other direction, and 3. electrically controlled actuator means comprising rotor arms extending outwardly from opposite sides of said outer end portion of said control shaft and having outer free ends, and electromagnetic means associated with each of said rotor arms, said electromagnetic means being selectively operable to selectively attract said associated rotor arm and correspondingly reciprocate said control shaft to selectively position the associated pattern lever, said rotor arms constituting opposite poles of a permanent magnet whereby said rotor arms are held in the switched positions by the permanent magnet constituted by said rotor arms, and wherein said selector devices each comprise upper and lower field plates, end plates, connected to and maintaining said field plates in spaced apart relationship above and below said control shaft, said end plates including bearing supports for portions of said control shaft adjacent the inner and outer ends of said rotor arms, coil pieces positioned between said field plates, coils surrounding each of said coil pieces and spaced from the free ends of said rotor arms, ribs extending inwardly from said upper and lower field plates and above and below said rotor arms and forming air gaps in which said rotor arms operate, and b. pattern control means operating in timed relationship to operation of said knitting machine and being operable to supply electrical pulses to said electrically controlled actuator means in accordance with a predetermined knitting pattern to thereby selectively position said pattern levers of said selector devices.