Anyone knows what this is for? Looks like a clamp?

[lorenzospain]

Hi I'm Lorenzo from Spain, new here, hope someone can help me out! Found this at a Spanish second hand shop. There are four wing bolts with their individual springs in between the two wooden frames, making it possible to tighten each corner of the frame separately. Any idea what its purpose is?

 

[Jake]

It's for storing wooden tennis rackets to keep them from bowing.

 

[Sideways]

My mother's (wooden) racket was always stored clamped in one of these.

 

[Katomi woodsmith]

As above posts, I knew straight away having seen my mothers one for many years.
In addition to bowing the rackets were carried to matches in these fames for protection.

 

[Sachakins]

Just to add to the above, the tension of strings of rackets could deform it if left free.

 

[TomGW]

Unfortunately I'm also at the age that I recognised it instantly. Generation gap here.

 

[sneggysteve]

I had one of these !!!

 

[MorrisWoodman12]

I had one of these until quite recently when I gifted it to my local tennis club to display on the wall. For an instant I thought it was mine as the initials are almost identical.