Screw 1 is driven by worm 2 and worm wheel 3 through a key which is held in worm wheel 3 and slides along a keyway cut along the length of screw 1. Screw 1 fits the thread of half-nut 4 on lever 5. Spring 6 holds the half-nut in contact with screw 1 which travels to the left when rotated. When screw 1 reaches setscrew 7 it pushes back lever 8 so that the stopping device of the machine (not shown) is disengaged from notch a and the machine stops. At this, shaft A ceases rotation. The time the machine operates before being disengaged is varied by adjusting setscrew 7.
$2245$LS,SE$