| 摘要 |
<p>A knife holder with pref. four blades mounted at equal angular spacings, is carried on a pivot shaft parallel to the direction of ejection to the tubing from the extruder, in a plane radial to that pivot and rotating around it. The blades can be heated and the holder is rotated by a lever arm, a ratchet and pawl coupling and initially by a hydraulic ram. The knife holder also has an index wheel which retains the knife holder away from the work before the cutting operation, a spring loaded stop in the slots of this wheel being disengaged by a tongue on the stop riding on a cam plate fixed to the one way coupling.</p> |
