Flexible link (steel belt) 6 runs over pulleys 1 and 7 which rotate about fixed axes K and Q. Slide 2 is reciprocated by alternately engaging and disengaging opposite sides of the steel belt which is gripped between prong B or C of four-arm tumbler lever 4 and lug M or N of the slide. Lever 4 turns about axis F of slide 2. As shown, belt 6 is gripped between prong B of lever 4 and lug M of slide 2 which travels in the same direction (to the left) as the top side of the belt. At the extreme left position of slide 2, arm A of lever 4 engages fixed stop D, turning the lever clockwise so that prong B is disengaged from belt 6 whose bottom side is gripped between prong C of lever 4 and lug N on the slide. At this, slide 2 travels to the right until arm A engages fixed stop E, reversing the slide again. Plunger 5, actuated by spring 3, has a conical head which contacts either the upper or lower bevel of prong H of lever 4, locking the lever in either of its two positions. Slide 2 travels along rollers 8 to reduce friction in its reciprocating motion.
$3656$CFL,SE$