Abstract: A traversing mechanism converts rotary motion of a rotating shaft into reciprocating motion back and forth along the shaft by the provision of a carriage housing slidably mounted on the shaft and traversed by a friction roll. The friction roll is journalled in a gimbal type structure alongside the shaft and the gimbal ring is pressed against the shaft by a plurality of annular Belleville springs. The gimbal ring depends by a pair of pivoted links from its swivel shank to swing as it, and the friction roll are skewed at the end of the path by a reversing rod.