| 摘要 |
PURPOSE:To permit wrapping film to be strongly pressed between an upper and lower seal bar by supporting the upper seal bar on the upper end of a crank rod and securing a lower seal bar in a shaft receiving hole formed at an eccentric part of a driven gear in such manner as to work them against each other. CONSTITUTION:A narrower guide rod 18 is extended from the upper stopper face 17 of a crank rod 16 and an upper seal bar 20 is vertically slidably supported by this guide rod in engagement into a hole 19 formed at each end thereof and securely pressed against the aforesaid stopper face 17 by the force of a spring 22. A lower seal bar 30 is supported between two driven gears 27 with a pin 32 at each end thereof rotatably supported by shaft receiving holes. When a pair of upper and lower gears 13 and 27 in mesh with each other changes the angle of rotation synchronously, the crank rod 16 moves while retained in a vertical position to work the upper and lower seal bars 20 and 30 against each other, thereby pressing wrapping film between such two opposing forces. |
