Pneumatic material handling system for combines

In a self-propelled combine of the type including a header, a feed mechanism for feeding crops into the combine, a threshing cylinder for separating grain crops and the like, chaff and straw, straw-walkers for removing straw from the combine, a chaffer sieve for receiving chaff and straw from the cylinder, a clean grain sieve positioned below the chaffer sieve for separating grain from chaff, a cleaning fan for directing air through the sieves to facilitate separation of the grain from the chaff, a grain tank in which grain is collected;

• the improvement comprising an elongate clean grain collection tube extending transversely of the combine below the chaffer and clean grain sieves for receiving clean grain therein, said clean grain collection tube having an inlet and an outlet;
• a fan for producing a stream of air, a conduit interconnecting said fan with the inlet of said clean grain collection tube for supplying air under pressure to the clean-grain collection tube;
• a cyclone structure on said combine and communicating with a grain tank, conduit means interconnecting the outlet of said clean grain collection tube with said cyclone whereby grain in the clean grain collection tube will be entrained in a stream of air and directed to said cyclone to permit grain to be discharged into the grain tank;
• an airlock device including an elongate housing positioned above said clean grain collection tube and having an elongate outlet therein communicating with the clean grain collection tube, said housing having an inlet therein for receiving clean grain therethrough;
• said airlock device including an elongate driven airlock mechanism positioned in the associated airlock housing and being revolvable relative thereto, said airlock mechanism including a shaft having a plurality of blades secured thereto and extending outwardly therefrom, each blade having a tip portion engaging the innner surface of the associated housing during rotation of the blade to form an airseal thereat, said airlock mechanism being operable to meter a predetermined amount of clean grain into the clean grain collection tube while preventing air under pressure from escaping from the clean grain tube.