[PieterCasparzen]

I think the hinge was attached to the handle and to the cover.

Is that your question - what sort of hinge was used ?

[Smokeyblue]

"I think the hinge was attached to the handle and to the cover."

Oh. I never thought about the handle having the hinge. That is interesting but... Think of two tennis rackets next to each other. You want to rotate one or the other or both so that they lay on top of each other. Not sure if that helps.