bed screw

from The Collaborative International Dictionary of English v.0.48

Bed screw \Bed" screw`\
   1. (Naut.) A form of jack screw for lifting large bodies, and
      assisting in launching.
      [1913 Webster]

   2. A long screw formerly used to fasten a bedpost to one of
      the adjacent side pieces.
      [1913 Webster]