Patent GB-674432-A (GB)
Title: Improvements relating to circular knitting machines
IPC: D04B9/46
Filed: 1950-01-16
Abstract: 674,432. Knitting-machines. SCOTT & WILLIAMS, Inc. Jan. 16, 1950 [Feb. 7, 1949], No. 1103/50. Class 74 (ii). To enable the inward movement of the sinkers S of a circular machine to be adjusted to compensate for the variation in loop length effected by the needles when the needle cylinder 260 or the stitch cam is raised or lowered, thereby maintaining a constant pressure against the stitches throughout the knitting cycle, a sinker stop is provided in the form of a ring 273 disposed within the needle cylinder and having an outturned flange provided with a bevelled edge 272 which is engaged by the sinkers. By raising or lowering the needle cylinder and sinkers relative to the ring 273, or the ring relative to and in conjunction with the needle cylinder or stitch cam the distance which the sinkers can move inwardly is varied since the radial point or edge of abutment of the bevelled edge 272 of the stop ring 273 with the abutting point or edge 293 of the sinkers moves inwardly or outwardly with relative vertical movement between the sinkers and the stop ring. The edge 293 of the sinkers abutting the stop bevel 272 may be correspondingly bevelled. In one arrangement the stop ring 273 is secured against vertical displacement by being attached through a sleeve to the sleeve gear rotating the needle cylinder, the sleeve gear being vertically immovable. The needle cylinder is raised or lowered to effect vertical movement of the sinkers by a lever 281, acted upon by cams 501 ... 504 to vary the length of loop drawn by the needles in the welt, heel and toe of a stocking. Variation in loop length of the leg of the stocking is further effected by a cam 284, acting on a lever 282 extending from the lever 281, which is normally rotated by a lug 286 connected to a shaft 80 engaging a pin 288 on the cam. From the calf to the angle of the stocking it becomes necessary to advance the cam at an increased rate to effect a more pronounced loop variation between the courses. This is attained by a ratchet wheel 285 secured to the cam and rotated by a pawl 73 operated by the quadrant gear. A portion of the ratchet wheel is blank to prevent the pawl from rotating it at this stage and which portion corresponds to the upper portion of the leg of the stocking during which the cam 284 is rotated by the lug 286. Rotation of the cam and ratchet wheel 285 eventually brings the teeth of the wheel into engagement with the continuously operated pawl which then commences to advance the cam at a rate exceeding that advanced by the lug. When the pawl again engages the blank portion of the wheel, the cam remains stationary until the lug is advanced sufficiently to re-engage the pin 288. Alternatively the ring stop 273 may be raised or lowered relatively to the needle cylinder in which case the ring stop is secured to a sleeve slidable within the needle cylinder and raised or lowered by levers operated from a cam drum. The combination of separate means raising and lowering the needle cylinder, the ring stop and the needle cam may be used to obtain a variation in loop length during the knitting of a stocking.