I have no idea where my buddy found the latch, but it was in some industrial parts catalog. It works pretty simply. The latch is attached to a square ended U and the U swings freely. That assembly is attached to the swing arm.
On the bumper there is a little "cup" that accepts the end of the swingarm into it and serves as a stop. On that stop there is a tab that came with the latch that has one end ground out in another U shape to accept the U of the latch end.
So, I know that explanation sucked, but you swing the carrier into the receiver, pull open the latch and swing out the U shaped arm, which fits over the tab on the stop, then pull the latch shut and the two Us pull it in tight. Close the latch and whalla, it doesnt move!
Does that make any sense at all? I am assuming it doesnt since I can hardly undertand it and i wrote it. So, later on tonight I will take some pics and post them up tomorrow.
So far the only flaw to the design is it can wiggle itself loose over long periods of highway driving, which I think could be remedied by adjusting the latch a little. And its fairly easy to catch with your pants, or shirt and pull it loose, then its VERY frightening to see your swing arm opening giong 75 down the freeway!
Hope that helps, I will get some pics later on.
josh