Abstract: A coupling assembly for interconnecting a pair of implements such as grain drills in end-to-end relation for towing behind a tractor for field operation and in an endwise direction for transport. The grain drills are connected to a tractor by conventional duplex hitch structure. The grain drills are connected to each other by a novel coupling assembly which in field operation permits the adjacent drills to move within limits toward and away from each other to accommodate ground level variations. The coupling assembly includes a latch unit positionable to lock the coupling assembly to thus retain the drills in fixed spaced relation to facilitate endwise transport of the drills.