Patent ID: 7878029

Claim:
A circular knitting machine for the production of men's socks, comprising: a cylinder having a rotation axis, rotating in a controllable manner around said axis, and having a plurality of axial grooves on the external surface; a plurality of cylinder needles, held so that they can slide along said axial grooves of the cylinder; a mechanism for moving the cylinder needles, able to impose a translation in alternate directions on the cylinder needles between a lower limit position and an upper limit position, axially higher than the lower limit position; a fixed external crown, which surrounds the cylinder, co-axial with it, fitted with a plurality of crown grooves; a plurality of sinkers, held so as to be able to slide along said crown grooves; a mechanism for moving the sinkers, able to impose a translation in alternate directions on the sinkers between a rearward limit position and a forward limit position, radially internal to the rearward limit position; a dial, positioned in such a way as to surmount the cylinder, coaxial with it, rotating on command around the rotation axis of the cylinder, fitted with a plurality of radial grooves, extending radially inside the outer surface of the cylinder; a dial shaft, connected to the dial to drag it in rotation; a plurality of dial needles, held so that they can slide along said radial grooves of the dial; a mechanism for moving the dial needles, which can engage with said dial needles and able to impose translation in alternate directions on the dial needles, between a rearward limit position and a forward limit position, radially external to the rearward limit position; at least one yarn-finger able to feed at least one yarn for the creation of the sock; wherein the cylinder needles, dial needles and sinkers co-operate to interlace the yarn and form the stitches which compose the sock; a dial needles selector mechanism, able to selectively move the dial needles to translate them from a disengaged position to an engaged position, in which they can be engaged by said mechanism for moving the dial needles, involving the selected needles in the formation of the stitches and excluding the non-selected needles; a mechanical traction mechanism able to exert a pulling effect on the sock being formed by means of mechanical gripping of the sock being formed, the mechanism comprising: a suction tube inside the cylinder, rotating jointly with it; a tubular bush, inside the suction tube, rotating jointly with it, axially translatable in it; a mechanism for moving the bush axially; and a gripping device, translatable to the inside of the suction tube inside the bush, able to be commanded so as to form releasable gripping elements so as to drag at least a portion of the sock being formed against the bush, to pinch it mechanically; wherein the mechanism comprises a spindle inside the dial shaft, sliding axially, connected to the gripping device.