How do lock out hubs work on a Chevy 4 wheel drive?

Lock out hubs release a tensioned spring that holds a splined gear over the outter end of the front drive axle. These cogs are splined to the axle on their inside,and geared to the hubs on their outside perimeter , making the connection between the two when locked in. These are located on each outter axle end ,in the hubs, at the center of the front wheels. When unlocked the front axles and front driveshaft are no longer forced to turn with the tire.