Stacker

Abstract

A bag stacker useful for plastic bags having a fence for stopping forwardly projected bags, raisable to permit a completed stack to move forward, a conveyor passing beneath the fence, a clamp moving with the conveyer to draw the completed stacks forward beneath the fence and a bag support arranged to assume, when the clamp engages a completed stack of bags, a position rearward of the fence, to receive and support bags arriving subsequently, this support being movable forward of the fence to disengage from accumulated bags. Preferably fingers extend below the fence and have trailing ends movable between raised and lowered levels and from a rearward position in which the ends extend rearwardly beyond the fence. These fingers move to the forward position prior to raising the fence and to the rearward position when the fence is raised and before the support is drawn forward of the fence, to insert the finger ends into the space between the clamp and support and thereby between completed and newly forming stacks. The support joins the clamp in a narrow edge facing incoming bags; the fence is counterbalanced, preferably free floating down, and rests lightly on the conveyor or stack; and the fence is mounted on rotary arms, preferably a parallelogram, pivoted to the supports to carry the fence close to the conveyor in bag-stopping position over the range of vertical adjustment. The conveyor and clamp travel in parallel paths driven by an adjustable stroke rack with a clutch enabling reverse motion only of the drive belt for the clamp motion of the rack.