Toothed gear 1 rotates about axis A and meshes with pin rack 2 having pins d. Trunnion A of gear 1 slides along fixed slot a-a. When driving gear 1 rotates continuously in one direction at uniform velocity, driven rack 2 reciprocates at uniform velocity along fixed guides b-b. Rack 2 is reversed by circular lugs c which guide trunnion A. While gear 1 is passing from its upper to its lower position and vice versa, rack 2 travels with nonuniform velocity. The profiles of teeth e of gear 1 are along curves which are equidistant from an involute of a circle.
$2579$PG,3L$