Helical spring clutch

Claim 1

A brake mechanism comprising a clutch having a normally rotatable input member and a normally stationary output member supported for relative rotation about a common axis, a coiled helical spring telescoped with said members and having one of its ends connected to said output member, a normally stationary collar telescoped with at least one of said members and connected to the other end of said spring, means for causing said collar to shift axially into and out of frictional engagement with said input member, said collar being rotated by said input member when in frictional engagement with said input member and being operable when rotated to cause said spring to flex radially and couple said output member for rotation with said input member, a disc rigid with and projecting radially from said output member, a brake comprising friction material located to rub against said disc and operable to frictionally retard rotation of said disc and said output member and thereby retard rotation of said input member when the latter is coupled to said output member by said spring, and resiliently yieldable means for pressing said friction material against said disc.