Abstract: A planter population reduction drive system includes a third shaft adapted to be added onto a planter implement transmission unit having existing first and second shafts. The individual planter units are driven by the second shaft which is connected by a series of adjustable wheels to the first shaft for a selected population rate. The new third shaft is driven by the ground wheels and includes primary and secondary belt drive connections to the first shaft. A normally engaged wrap spring clutch on the third shaft normally provides for the transmission of torque from the third shaft to the first shaft but when the wrap spring clutch is disengaged, torque is transmitted through a secondary drive wheel which is mounted on the third shaft by an over running clutch.

Abstract: A planter population reduction drive system includes a third shaft adapted to be added onto a planter implement transmission unit having existing first and second shafts. The individual planter units are driven by the second shaft which is connected by a series of adjustable sprockets to the first shaft for a selected population rate. The new third shaft is driven by the ground wheels and includes primary and secondary chain drive connections to the first shaft. A normally engaged wrap spring clutch on the third shaft normally provides for the transmission of torque from the third shaft to the first shaft but when the wrap spring clutch is disengaged, torque is transmitted through a secondary drive sprocket which is mounted on the third shaft by an over running clutch.