Patent ID: 8056883

Claim:
A drive unit, comprising: a mounting plate; a shaft rotatably connected to said mounting plate; a spool coaxially positioned along said shaft, wherein said spool rotates independently of said shaft; at least one elongated member wound upon said spool; a hand crank connected to said shaft for winding or unwinding said at least one elongated member upon said spool; and a brake assembly mounted to said drive unit, wherein said brake assembly includes a torsion spring; wherein a first force applied with said hand crank in a first rotational direction upon said torsion spring lessens a tension of said torsion spring allowing said torsion spring and said spool to rotate; wherein a second force applied with said spool in a second rotational direction upon said torsion spring increases a tension of said torsion spring preventing said torsion spring and said spool from rotating.