| 摘要 |
PURPOSE:To obtain a bore contracting device to allow automatical formation of a bore-contracted part at the rear end of an outer straw by a method wherein a screw roller to forcibly shift a straw toward a heat forming disc is provided so as to push the end of of the straw together with the shifting of the straw in the forming recess of the heat forming disc in order to contract the bore of the straw at its end. CONSTITUTION:A straw led in to the position 5 is guided by a transferring passage 15 consisting of spiral rods 21 and 22 and an outer straw is transferred toward a heat forming disc 26 by means of th rotary feeding action of a screw roller 29 so as to push the base end of the outer straw in the forming recess 27 of the heat forming disc 26, which rotatively operates in synchronism with the transferring speed of the straw, in order to contract the bore and to shape the end of the straw. When the straw is transferred further, the base end of the straw comes out of the recess 27 because of the rotation of the heat forming disc 26 and then the outer straw is led out in the direction opposite to the disc by means of a screw roller 31. |
