Patent ID: 8079235

Claim:
A circular knitting machine, comprising: (a) a knitting head fed with yarns and operable to knit a continuous fabric tube, the knitting head comprising: a stationary base plate; a plurality of needles carried by a rotating cylinder, the cylinder having an upper portion disposed above the base plate and a lower portion disposed below the base plate, the needles being movable up and down in vertical channels defined in the upper portion of the cylinder, the cylinder being rotatable about a cylinder axis; a vertical drive shaft rotatable about an axis displaced from the cylinder axis; a drive pinion affixed to the drive shaft and a cylinder drive gear affixed to the cylinder, the drive pinion engaging the cylinder drive gear such that rotation of the drive shaft causes rotation of the cylinder about the cylinder axis; a cam box supported by the base plate and configured to surround a radially outer surface of the cylinder; a plurality of needle cams affixed to a radially inwardly facing side of the cam box opposing the cylinder, the cams interacting with butts on the needles such that the needles are driven up and down as the needles are carried along by the rotating cylinder; (b) a take-down unit receiving the fabric tube descending from the knitting head and operable to flatten the fabric tube; (c) a wind-up and storage unit receiving the flattened fabric tube from the take-down unit and operable to wind the flattened fabric tube into a roll; and (d) a bearing system incorporated into the knitting head and comprising first and second bearings surrounding the cylinder and constraining the cylinder to rotate about the cylinder axis defined by the bearing system, the first bearing being disposed above and vertically spaced from the second bearing, the first and second bearings comprising: a ring-shaped inner race for the first bearing, and a ring-shaped inner race for the second bearing, the inner races being affixed to the cylinder for rotation therewith; a ring-shaped outer race for the first bearing and a ring-shaped outer race for the second bearing, the outer races being secured to the base plate; and a plurality of first bearing elements captured between the inner and outer races of the first bearing, and a plurality of second bearing elements captured between the inner and outer races of the second bearing.