US Patent 7252262 Protective cover for optical fiber

A protective cover is detachably fixed onto a spool to protect an optical fiber wound on the spool. The protective cover includes a pair of half-cylindrical cover members coupled together by a hinge and locked together by a locking mechanism. When an external force allows a pair of hinge members of the hinge to abut together, edges of the cover members are apart from each other at an angle of 2 to 7 degrees as viewed with respect to the center of the hinge. The edges of the cover members are then abut together by an additional external force to lock the locking mechanism.