Circular gear 1 rotates about fixed axis A and meshes with circular gear 2. Link 4 turns about axis A and is connected by turning pair B to gear 2. Gear 2 meshes with noncircular gear 3 which rotates about fixed axis C. Portions a-a and b-b of the pitch curve of gear 3 are circular arcs of radii r and r'. When driving gear 1 rotates, driven link 4 oscillates and has two dwells during the periods when arcs a-a and b-b of gear 3 are in engagement with gear 2. The mechanism can also be employed to obtain a variable transmission ratio from gear 1 to gear 3. Owing to gear 2, gears 1 and 3 rotate in the same direction. Gears 2 and 3 are held in engagement by the weight of gear 2.
$2518$LrG,D$