Abstract: The bin unloader belt drive for a combine includes a clutching idler mechanism in which the start-up torque delivered by the belt (11) from a drive pulley (12) to a driven pulley (13) is limited by using a dampener (51) which retards the spring biased movement of a clutching idler pulley (21) from its drive disestablishing position to its drive establishing position.

Abstract: A pivoted safety door for a harvester is disposed ahead of the concave and has a separately pivoted lip which normally rests on a front edge of the concave. An adjustably biased detent mechanism releases the lip, permitting it to pivot out of engagement with the concave, when a rock or the like of substantial size attempts to enter the threshing chamber and is engaged by the threshing rotor. A first manual control is provided for pivoting the main body of the door from its tripped position to a closed position. A second manual control is provided for pivoting the lip relative to the door to restore it to its detented position, this last mentioned function being effected after the main body of the door has been restored to a closed position. The detent mechanism for the lip includes a pair of adjustably loaded spring biased plungers which act on opposite sides of a detented part.