VENT FORMER FOR SHRINK-PACKAGING FILM

摘要

PROBLEM TO BE SOLVED: To prevent a needle member from dropping from a rotary body and to adjust an amount of projection of the tip of its needle. SOLUTION: A spindle 22 is passed through an insertion hole 24a of the rotary body 24. A cavity 36 is defined between the inner surface of a needle attachment portion 34 of the rotary body 24 and the outer peripheral surface of the spindle 22. The needle member 40 for forming a vent hole on a film 10 is provided on the needle attachment portion 34. The needle member 40 is positioned by a positioning screw 42 spirally inserted into the rotary body 24 so that the amount of projection of the tip of its needle from the outer peripheral surface of the rotary body can be adjusted. A side projection machining portion 40a is formed at the rear end part of the member 40 which is exposed to the cavity 36. The side projection machining portion 40a is limited in movement in contact with the inner surface of the needle attachment portion 34 or the outer peripheral surface of the spindle 22, thereby preventing the needle member 40 from dropping outward and inward from the attachment portion 34. COPYRIGHT: (C)2005,JPO&NCIPI