R 408.12431 Single stroke.

Rule 2431. (1) Presses using full-revolution clutches shall incorporate a single- stroke mechanism, except that the single-stroke mechanism may be omitted if either of the following conditions is met: (a) A press has barrier guards as prescribed in R 408.12462(1), (2), and (3) on all 4 sides and a second action is required to initiate the cycle after the machine has been energized by the start switch. (b) A press is operated by 2 hand anti-repeat trips. (2) If the single-stroke mechanism is dependent upon spring action, the spring shall be of the compression type, operating on a rod or guided within a hole or tube, and designed to prevent interleaving of the spring coils in event of breakage.