Single-tooth driving gear 1 is keyed to shaft d, rotates about fixed axis A and meshes alternately with external gear 2 and internal gear 3, rotating one of them a fraction of a revolution at a time and locking the other during this time. The locking effect is obtained by the engagement of concentric locking surface a on gear 1 and concave surfaces b on gear 2 or c on gear 3. Gears 2 and 4 are keyed to shaft e, and internal gear 5 is keyed to the sleeve of gear 3 which rotates freely on shaft e. The rotation of gears 3 and 5 or of gears 2 and 4 is transmitted to planet gear 6 which rolls around gear 4 or in gear 5, whichever is stationary at the time. Planet gear 6 is connected by a turning pair to carrier 7 and rotates it about shaft e. Carrier 7 is rigidly attached to sprocket 9 over which conveyer chain 8 runs. Thus, when shaft d rotates continuously in one direction, chain sprocket 9 rotates intermittently, first in the forward direction and then a smaller amount in the reverse direction. This cycle of motion is repeated.
$2971$CxG,FD$