Multisystem circular knitting machine having electromagnetic needle selection

A multisystem circular knitting machine comprising a needle cylinder supported for rotation about a central axis and having axially oriented guiding slots in its jacket, each of said slots guiding a needle and a selecting jack arranged below the needle, each selecting jack having fulcrum portion for imparting a swinging movement thereto and a resetting spring, a cam race assembly surrounding said needle cylinder and including a stationary supporting plate secured to a machine frame, a plurality of radially directed ribs mounted on said supporting plate, a supporting ring mounted on said ribs, a jack cam race mounted on said supporting ring and a needle cam race mounted on said jack cam race, a lower part of said needle cylinder opposite said support ring and said radially directed ring being formed with a circumferential recess communicating with free spacings between said ribs, lower end portions of said selecting jacks each being provided with an armature surface overlapping said guiding slots, electromagnetic needle selection means including a plurality of electromagnets arranged at predetermined selection points in said circumferential recess, each of said electromagnets being mounted at one end of a bar-shaped support member inserted into a spacing between said radial ribs and being adjustably secured to a lower side of said supporting ring, and said jack cam race including pairs of circumferentially offset and axially superposed pressing cams assigned to respective systems of the machine to engage said end portions of said selecting jacks and to move their armature surfaces against said electromagnets at respective selection points, the lower one of said pressing cams engaging said end portion of the selecting jack first and moving the same radially inwardly at a relatively slow rate of a transfer point before said selection point, and the upper pressing cam taking over said end portion of the selecting jack at said transfer point and moving said end portion at a higher rate in contact with said electromagnet at said selection point.