| 摘要 |
PURPOSE:To alleviate a bending stress operating at a plunger and to prevent glass fiber from cutting or damaging by providing a supporting piece near the end of the plunger, and so forming the planar shape of the piece as to narrow it toward a rear side. CONSTITUTION:Protruding supporting pieces 31 are provided at an equal interval at three circumferential positions on the outer surface of a plunger 4 at the rear side of the checking part 4b of the plunger 4, and the end faces of the outer surfaces of the pieces 31 are slidably brought into contact with the inner surface of a barrel 2. Since the rear sides of the pieces 31 are narrowed in the planar shapes when a material passes a passage among the pieces 31, the material is moved forward along the side face of the streamline shape of the pieces 31. Thus, glass fiber smoothly flow without damaging. Since a stuffing plunger 8 is pressed in a state that the plunger 4 is rotated, a bending stress is operated as the plunger 4, but the plunger 4 is formed in a both ends supporting structure to be smoothly rotated and strong against the bending stress. |
