The apparatus may further include Skein reed

The cam includes a raising cam portion, a stitch cam portion, and a welt cam portion in which tension forces between yarn loops and hooks bias the butts of intact needles against the first cam face. The apparatus may further include Skein reed means for stopping operation of the knitting machine when the sensor is activated. .; The recess is formed so that the second cam face is sufficiently spaced from the first cam face so that butts of needles having broken hooks are urged into the recess segment by the detector butt lowering segment, but butts of intact needles that are biased against the first cam face do not enter the detector recess segment. The detector has a detector butt raising segment wherein the second cam face in the welt cam portion is inclined away from the second cam face at the stitch position for urging butts toward the first cam face