Conveyor system including a chain drive for driving an endless belt in tensioned condition

Claim 1

A conveyor assembly comprising: a frame member; an endless chain slidingly mounted on and spirally coursed in a given peripheral direction about a plurality of turns about an internal cylinder defined by said frame member, said chain being formed of a plurality of spaced pins; drive means for said endless chain for circulating said endless chain around said frame member, said drive means including a vertical drive shaft member driven by a motor, and provided with a plurality of spaced apart chain drive sprockets, a plurality of paired idler sprockets and a plurality of tensioning chain sprockets, each of said chain drive sprockets being mounted on said vertical drive shaft member at a height corresponding to a turn of said endless chain about said frame member, each of said paired idler sprockets cooperating with a respective chain drive sprocket, each of said tensioning chain sprockets cooperating with a respective one of said chain drive sprockets and cooperating paired idler sprockets whereby said endless chain is coursed at each of said respective turns from said frame member to a respective spaced apart chain drive sprocket and back to said frame member by cooperating paired idler sprockets and tensioning chain sprocket thereby to drive said endless chain at each of said respective turns about said internal cylinder; an endless belt spirally coiled around said frame member for bearing edgewise in driving contact substantially about said internal cylinder of said endless chain between pins thereof whereby driving contact of said endless chains with said endless belt is effected substantially about each of said turns to cause circulation of said endless belt about said frame member; and drive means for said endless belt for tensioning said endless belt to cause said endless belt to come into driving contact with said endless chain substantially about said internal cylinder thereby to circulate said endless belt about said frame member, said drive means including torque means coupled thereto for changing torque of said drive means for said endless belt.