Pinion 1 and gear 2 rotate about fixed axes A and B. Rotation of pinion 1 is transmitted to shaft 4 with a certain lag. Gear 2, sector 3 and sector 5 are mounted freely on shaft 4. Sector 3 has circular slot b. Sectors 3 and 5 are connected together by pin d which is rigidly mounted in sector 5 and enters slot b. Link 6 is rigidly mounted on (keyed to) shaft 4. When pinion 1 begins to rotate, it drives gear 2, but shaft 4 will remain stationary until pin a turns sector 3 which, in turning, brings pin d into engagement with the lug of link 6. After this, shaft 4 begins to rotate.
$2358$SG,D$