The cam lifter feed mechanism of this invention comprises an inclined endless chain conveyor reducers for greenhouse carried by an upper framework and a lower framework including a multiplicity of lug-like lumber engaging means mounted at intervals on the endless chains of the conveyor, a driven shaft journaled for roatation in the upper framework including sprockets operatively engaged with endless chains of the conveyor, a plurality of cam lifters mounted on the shaft at opposite terminal sides of the endless chain conveyor including outwardly projecting hook-like foot portions getting operable to engage the lowermost terminal edge of lumber carried on the conveyor by the lug-like engaging means and also to carry the lumber over the shaft to a point of discharge, a downwardly inclined discharge feed guide means mounted on the upper framework between cam lifters. The low platform having a set of other hopper developing downwardly likely part body associates being operable to steer lumber toward the endless chain conveyor, means mounting the limitless string conveyor distally close to the lowermost end of the downwardly inclined side framework member. The hook-like foot servings each possess a leading edge downwardly willing with regards to the radii of the cam lifter at an angle coincident with the angle of inclination of the endless chain conveyor, the foot part giving upwardly from the leading edge right into a catch developing portion.