Abstract: In a piston press for bales of harvested material, comprising a plunger piston (K) movable forwards and backwards, a feeding channel (Z) including a reel (R), driven by a crank mechanism, with reel levers (10) on a crankshaft journal (8) of the crank mechanism, a control drive, and a switching device (V) for changing the movement path (l, f) of the reel tips between loading and feeding strokes, wherein a control arm (11) elongating the reel lever (10) is coupled with a control rod (13) supported in a displaceable control joint (G) and the control joint (G) is fixable in at least one position corresponding to a feeding stroke movement path, the control joint (G) is fixed only in the position for a feeding stroke (l) while it remains freely movable during each loading stroke (f).