Abstract: A circular knitting machine having a needle selection device and a device for axially shifting needles which has an axially movable cam. The axially movable cam defines a contour and is movable to three levels corresponding to a knitting position, a tuck position, and a float position. The device is arranged in correspondence with the feed stations of a circular knitting machine, such that butts of needles not moved into operation by jacks traverse the contour of the axially movable cam. The contour raises the needles not moved into operation by the jacks with a substantial delay with respect to other needles moved into operation by the jacks under control of the needle selection device.

Abstract: An electromagnetic selector device comprising a single permanent magnet and a plurality of electromagnets, which are excited in contrast or in agreement with the permanent magnet, to form a plurality of selection positions on two fronts along which run the elements to be selected.

Abstract: A device for needle selection in a circular knitting machine consisting of springs lying below the elastic jacks and rotating with them, to be deformed axially and be retained in their deformed position or to be released therefrom by electromagnetic selectors, in order, respectively, not to retain the elastic jack and thus allow it to rise and activate its respective needle, or to retain the elastic jack flexed within its trick and thus not allow it to activate its needle.

Abstract: A device for selecting needles in a circular knitting machine of the elastic jack type, comprising auxiliary jacks positioned below and in the same tricks as the elastic jacks. The auxiliary jacks are selected electromagnetically so that they act to radially lock the elastic jacks while these are in their flexed position within the tricks so that they cannot return outwards and thus engage their raising cams and activate their needle.