A concave for an agricultural combine includes opposite side plates or rails, each having a curved upper edge with a plurality of square notches formed in the upper edge. A series of rectangular bars are secured to the side rails via end tabs received in the notches, such that the bars are spaced longitudinally apart from one another to define uniform laterally extending gaps between adjacent bars. The concave is free from structures or obstructions in the gaps, so as to minimize plugging of the concave. Each bar has a leading edge with the radius to minimize damage to harvested grain during the threshing process.

Weed seeds are destroyed in the chaff from a combine harvester by repeated high speed impacts caused by a rotor mounted in one of a pair of side by side housings which accelerate the discarded seeds in a direction centrifugally away from the rotor onto a stator including angularly adjustable stator surfaces around the axis. Thus the discarded seeds rebound back and forth between the rotor and the stator to provide a plurality of impacts. The seeds are carried axially of the rotor by a controlled airstream so that they move to an axial discharge location where a discharge fan is mounted. The angle of the discharge around the rotor axis can be changed to direct the seeds to the side of the combine away from a straw chopper, towards the guide fins of the tailboard of the chopper, or into the housing of the straw chopper.

Weed seeds are destroyed in the chaff from a combine harvester by repeated high speed impacts caused by a rotor mounted in one of a pair of side by side housings which accelerate the discarded seeds in a direction centrifugally away from the rotor onto a stator including angularly adjustable stator surfaces around the axis. Thus the discarded seeds rebound back and forth between the rotor and the stator to provide a plurality of impacts. The seeds are carried axially of the rotor by a controlled airstream so that they move to an axial discharge location where a discharge fan is mounted. The angle of the discharge around the rotor axis can be changed to direct the seeds to the side of the combine away from a straw chopper, towards the guide fins of the tailboard of the chopper, or into the housing of the straw chopper.

A chopper for an agricultural harvester comprises a housing, a rotor, a bank of counter-knives, and an adjuster. The housing comprises a variable geometry outlet floor. The is positioned in an interior region of the housing for rotation therein relative to the housing. The bank of counter-knives is movable relative to the rotor between a first aggressiveness position and a second aggressiveness position to adjust chopping aggressiveness of the chopper. The outlet floor comprises a ramp movable relative to the rotor between a first ramp position and a second ramp position. The adjuster positions the ramp in the first ramp position when the bank of counter-knives is positioned in the first aggressiveness position and positions the ramp in the second ramp position when the bank of counter-knives is positioned in the second aggressiveness position.

A straw chopper for a combine harvester including a rotor supporting a plurality of chopping elements. A rotor housing including an inlet opening, an outlet axially aligned with the inlet opening, and at least one outlet that is axially offset from the inlet opening. A portion of the straw is conveyed tangentially to the axially-aligned outlet, whilst a further portion is conveyed from the inlet opening to the axially offset outlet(s) via a path having an axial component, for example a helical path. Guide vanes may be provided on the inside of the housing to impart an axial force upon the straw.

A straw chopper for a combine harvester including a rotor supporting a plurality of chopping elements. A rotor housing including an inlet opening, an outlet axially aligned with the inlet opening, and at least one outlet that is axially offset from the inlet opening. A portion of the straw is conveyed tangentially to the axially-aligned outlet, whilst a further portion is conveyed from the inlet opening to the axially offset outlet(s) via a path having an axial component, for example a helical path. Guide vanes may be provided on the inside of the housing to impart an axial force upon the straw.

A combine harvester separates crop into straw and chaff and weed seeds using a sieve, a chopping rotor with a spreading device and at least one weed seed devitalization section. The components can be operated in a first mode where both the first material and said second material are directed to the chopper and a second mode the first material is directed to the chopper inlet and the second material is directed to the WSD. This can be effected by providing a guide wall which has a leading edge attached adjacent a rear edge of the sieve and extends rearwardly therefrom. The chopper and the WSD can also be moved to provide the change of modes. A construction of destructor mill with an outer stator on the housing is also disclosed along with a method of feeding the lost grain to the WSD.

A combine harvester separates crop into straw and chaff and weed seeds using a sieve, a chopping rotor with a spreading device and at least one weed seed devitalization section. The components can be operated in a first mode where both the first material and said second material are directed to the chopper and a second mode the first material is directed to the chopper inlet and the second material is directed to the WSD. This can be effected by providing a guide wall which has a leading edge attached adjacent a rear edge of the sieve and extends rearwardly therefrom. The chopper and the WSD can also be moved to provide the change of modes. A construction of destructor mill with an outer stator on the housing is also disclosed along with a method of feeding the lost grain to the WSD.

A combine harvester separates crop into straw and chaff and weed seeds using a sieve, a chopping rotor with a spreading device and at least one weed seed devitalization section. The components can be operated in a first mode where both the first material and said second material are directed to the chopper and a second mode the first material is directed to the chopper inlet and the second material is directed to the WSD. This can be effected by providing a guide wall which has a leading edge attached adjacent a rear edge of the sieve and extends rearwardly therefrom. The chopper and the WSD can also be moved to provide the change of modes. A construction of destructor mill with an outer stator on the housing is also disclosed along with a method of feeding the lost grain to the WSD.

Weed seeds are destroyed in the chaff from a combine harvester by repeated high speed impacts caused by a rotor mounted in one of a pair of side by side housings which accelerate the discarded seeds in a direction centrifugally away from the rotor onto a stator including angularly adjustable stator surfaces around the axis. Thus the discarded seeds rebound back and forth between the rotor and the stator to provide a plurality of impacts. The seeds are carried axially of the rotor by a controlled airstream so that they move to an axial discharge location where a discharge fan is mounted. The angle of the discharge around the rotor axis can be changed to direct the seeds to the side of the combine away from a straw chopper, towards the guide fins of the tailboard of the chopper, or into the housing of the straw chopper.