PURPOSE: To prevent chips and the like from sticking to the inside of a hopper by providing a chip discharge opening at the pressing plate side end part of a bottom plate.

CONSTITUTION: A pressing plate 18 is slidable in longitudinal reciprocating motion in a hopper 14, and the lower end is provided with a slant face 29 so as to form a pointed edge part 31 opposed to a bottom plate 30c. A discharge opening 60 is formed between this edge part 31 and the rear end of the bottom plate 30c. A clearance between the edge part 31 and the bottom plate 30c is provided in an opposed position between the edge of the edge part 31 and the edge of the bottom plate 30c. A micro clearance is sufficient as this clearance but also allowed to be large. At the time of the pressing plate retreating in the hopper 14, the chip of cut material (a) accumulated on the bottom plate 30c can be thereby raked by the pointed edge part 31 of the pressing plate 18 and discharged outside of the hopper 14 from the opening 60.