Round ratchet-tooth rack 1 slides in vertical fixed guides a-a. Load Q is lifted by tie-rod 5 which oscillates lever 4 about fixed axis A. Pawl 3 is connected by turning pair B to lever 4 and engages the annular teeth of rack 1 to lift the rack intermittently. Downward motion of the rack (and dropping of load Q) is prevented by pawl 2 which turns about fixed axis C and is held in engagement with the teeth of rack 1 by spring 6.
$2769$RG,MH$