DOUBLE-CYLINDER CIRCULAR HOSIERY KNITTING MACHINE WITH DEVICE FOR TENSIONING THE MANUFACTURE

摘要

A double-cylinder circular hosiery knitting machine (1) with a device for tensioning the manufacture during its production, comprising a supporting structure (2) which is provided with a footing (3) and supports, so as to allow rotation about its own vertically oriented axis (4), a lower needle cylinder (5) and an upper needle cylinder (7), which can be positioned, during the production of the manufacture (12), above and coaxially with respect to said lower needle cylinder (5). The needle cylinders (5, 7) are actuatable with a rotary motion about their axes (4, 6) with respect to the supporting structure (2), and a device (11) for tensioning the manufacture (12) during its production is accommodated inside the needle cylinders (5, 7) and comprises means (13) for retaining the manufacture (12) proximate to the region where knitting is formed by needles (10) accommodated in the needle cylinders (5, 7), and a tensioning tube (14), which is accommodated in the upper needle cylinder (7) and is movable on command along the axis (6) of the upper needle cylinder (7). The lower end of the tensioning tube (14) is engageable, by sliding along the axis (6) of the upper needle cylinder (7), with the region of the manufacture (12) being formed that lies from the retention means (13) to the needles (10). The retention means (13) have a size suitable to allow the movement of the tensioning tube (14) about the retention means (13), and means (15) for the translational motion of the tensioning tube (14) along the axis (6) of the upper needle cylinder (7) are provided. The retention means (13) comprise a suction tube (16), which is accommodated internally and coaxially to the lower needle cylinder (5), and an element (17) for locking the manufacture (12), which faces the upper end of the suction tube (16) and is supported by the upper needle cylinder (7). The locking element (17) is movable on command along the axis (6) of the upper needle cylinder (7) to engage or disengage the upper end of the suction tube (16).