With a symmetrical 4-bar linkage, the same lifting movement moves the load the same distance, whether the load is close to the linkage or far from it.
However, the linkage is attached to a tractor and becomes a lever that pivots around the rear axle and wheel. A heavy load can be lifted close to the hitch and not farther back since it will then lift the front wheels.
Bruce
	
		
			
		
		
	
				
			However, the linkage is attached to a tractor and becomes a lever that pivots around the rear axle and wheel. A heavy load can be lifted close to the hitch and not farther back since it will then lift the front wheels.
Bruce