Does anyone recognize what this kind of hinge is for?

Question

I have a set of these hinges (at least, they seem to be hinges) but I'm not sure what they're for.

They measure about 1.5" (3cm) in the longest direction.

Here are some odd features:

• No obvious way to attach the parts on the left with the one on the right!

• Setscrew in U-shaped piece (second photo)

I assume these would be surface-mounted, they seem too thick to mortise into anything.

Answer 1

Hinge?

I look at that and see a clamp to assemble two panels at right-angles which is designed for easy assembly or disassembly and flat-packing.