Belt drive system

In an apparatus having a driving shaft which is rotatable at a first position in one direction only and a driven shaft which is rotatable at a second position remote from said first position, the improvement comprising a belt drive system for selectively rotating said driven shaft in said one direction and in an opposite direction, said belt drive system comprising, a driving sheave assembly fastened to said driving shaft, said driving sheave assembly having means defining a first belt-receiving groove and having a right circular cylindrical driving surface, a driven sheave assembly fastened to said driven shaft and having means defining a first and a second belt-receiving groove, a movable sheave assembly which is movable toward and away from said driving sheave assembly, said movable sheave assembly being defined by a pair of flange members having a pair of cooperating inclined surfaces defining a second belt-receiving groove with one of said flange members having a tubular portion extending from an edge portion thereof and a right circular cylindrical driven surface thereon, a first belt disposed in said first grooves for rotating said driven sheave asaembly in said one direction with said movable sheave assembly disposed in spaced relation from said driving sheave assembly, a second belt disposed in said second grooves, and means serving the dual purpose of moving said movable sheave assembly with its driven surface into engagement with said driving surface and creating slack in said first belt rendering it inoperative so that said driving sheave assembly provides rotation of said driven sheave assembly in said opposite direction through the action of said second belt.