Needle-selecting system for circular knitting machine

A circular knitting machine for the production of articles having an argyle or mosaic pattern, comprising a needle cylinder mounted for reciprocatory rotary motion and having latch needles, intermediate jacks and selection jacks provided with selection butts with which stacked arrays of selection levers cooperate, the latter being disposed to select the needles to be raised to knit by depressing said selection jacks, the latter being associated with elastic pusher jacks having respective butts;

• a bottom cam ring having lifting profiles arranged to cooperate with said pusher jacks;
• and a top cam ring having profiles arranged to cooperate with said intermediate jacks;
• wherein a stacked array of selection levers is disposed centered circumferentially between adjacent yarn feeding stations for selecting the needles to clear and knit in one or the other of said adjacent feeding stations depending upon the direction of said reciprocatory motion, said lifting profiles of said bottom cam ring being substantially symmetrically located with respect to said feeding stations and to said stacked arrays of selection levers, said profiles of said top cam ring being similarly symmetrically located for controlling and lowering said intermediate jacks, said profiles of said bottom cam ring having, in alignment with said selection levers, V-notched profiles with a bottom slightly lower than the lower dwell path of said butts of said elastic pusher jacks, while corresponding lower projections are provided on said top cam ring for the control and lowering of said intermediate jacks;
• the width of said V-notched profiles being less than that of said selection levers to obtain by elasticity the engagement and subsequent lifting of said butts of said pusher jacks on said lifting profiles, whenever one selection lever does not depress the relative corresponding butt of the selection jack, and the butt of said elastic pusher jack enters said V-notched profile and engages said lifting profile, in order to obtain said selection of said needles.