Turn orange nut to move yellow bars radially for centering a coil (in glass). Then the coil is turned for uncoiling. A brake drum on the pink shaft end is for creating uncoil tension.
Here is applied slider crank mechanism (green cranks, violet conrods and blue hub) to convert linear motion of the blue hub into rotary motion of the green cranks.
Parallelogram mechanisms are used for keeping yellow bars parallel to the pink shaft axis.
This uncoiler is for coils of large width.