When the shelf is pulled into the upright position, the hinged piece of 1/8" thick plywood will automatically fall down into this position.
The only hardware needed is a hinge, as gravity will do the rest. When putting the shelf back into the down position, all I need to do is push the 1/8" plywood back up into position, and the 1/2" plywood shelf will fold down easily.
I do plan on using one of these towards each end of the shelf, so between the 2 of them, they should hold the shelf nicely, and out of the way when not in use.
