Circular knitting machine with system for offsetting the plate of the needles with respect to the cylinder of the needles

A circular knitting machine (1) for knitted or hosiery items, comprising:

• a supporting structure;
• at least one needle-holding cylinder (C) turnably mounted in said supporting structure and selectively rotatable around an axis of rotation (X) of the knitting machine;
• a plurality of cylinder needles (N1) supported by said needle-holding cylinder (C) and movable in respective sliding seats (2) of the cylinder so as to produce a knitted fabric;
• a dial assembly (3) arranged above said needle-holding cylinder (C) and comprising:
• a supporting ring integral with said supporting structure and coaxial with said needle-holding cylinder;
• a needle-holding plate (P) turnably mounted on said supporting ring so as to be able to rotate around a respective axis of rotation corresponding to said axis of rotation (X) of the knitting machine;
• a plurality of plate needles (N2) supported by said needle-holding plate (P) and movable in respective sliding seats (5) of the plate so as to produce a knitted fabric;
• motion generation elements configured for putting said needle-holding cylinder (C) in rotation around the axis of rotation (X);
• motion transmission elements (10), operatively located between said motion generation elements and said dial assembly (3) and configured for creating a motion transmission chain that is able to transmit to the needle-holding plate (P) the rotation generated by the motion generation elements, so that the needle-holding cylinder (C) and the needle-holding plate (P) synchronously rotate, so that a specific angular rotation of the needle-holding cylinder (C) corresponds to an identical angular rotation of the needle-holding plate (P);
• the motion transmission elements (10) comprising:
• at least one first toothed wheel (11), receiving the rotary motion from the motion generation elements;
• at least one second toothed wheel (12), placed downstream of said first toothed wheel (11) along the motion transmission chain, and mounted coaxially with the needle-holding plate (P) so that a rotation of the second toothed wheel (12) corresponds to an identical rotation of the needle-holding plate (P);
• at least one offset device (20), located between said first toothed wheel (11) and said second toothed wheel (12), and comprising:
• an inlet gear (21), engaged with said first toothed wheel (11) so as to be put in rotation by the first toothed wheel;
• an outlet gear (22), engaged with said second toothed wheel (12) so as to put the second toothed wheel in rotation;
• wherein the inlet gear (21) and the outlet gear (22) are mounted coaxially with one another, so as to rotate around an axis of the offset device (Y);
• an actuator (25), acting upon the inlet gear (21) and/or upon the outlet gear (22) so as to shift, selectively and in a controlled manner, the inlet gear and/or the outlet gear along the axis of the offset device (Y), so as to change the engagement of the inlet gear (21) with the first toothed wheel (11) and/or the engagement of the outlet gear (22) with the second toothed gear (12).