Storage bin having driven agitator

In a structure of the class described:

• a hopper including an inner frustoconical surface having a vertical axis,
• an agitator within said hopper disposed parallel to said frustoconical surface and having a lower end and an upper end,
• means for driving the agitator in a circular path next to said frustoconical surface,
• said means including a pair of spaced circular raceway members facing away from said vertical axis,
• an elongate circular drive element riding on both of said raceways and spanning the distance therebetween,
• wheel means supporting the upper end of said agitator and riding on said frustoconical surface,
• connector means connecting said wheel means to said drive element whereby said raceway members and wheel means combine to hold the upper end of said agitator at a substantially fixed distance from said frustoconical surface,
• and reciprocating means engaging said elongate drive element for advancing the latter around said raceway and thus causing desired movement of said agitator.