Wondering through a huge antique store in Chicago this last weekend, I stumbled on this. Tagged as an 'antique camera' and nothing else, i decided this must be a bed for VERY large bellows camera.
In the lower right corner of the bed, running towards the back (towads the maniquin) is a flat gear rack. There is a solid steel bar (the cross section would be a 1/2 circle) that runs on top of the right and left wood rails of the top frame. The top wood frame is attached to the lower wood frame via a coiled steel spring and the spring is attached to a caster that is attached to the lower frame. Under each of the wood rails is a solid steel bar that is connected to each end and in the in the shape of an inverted 'V'. The two ends have a nut and jam nut.
The length is about 14' and the width is about 2'. It is about 18" high from floor to top of the top frame.
I have attached an annotated drawing to help with the description.
Anyone know what this is for?