| 摘要 |
PROBLEM TO BE SOLVED: To improve the abrasion resistance and reduction of noises of a guide member by receiving a roller for a push-pull chain by a guide section and rolling and roller when the push-pull chain is made to travel. SOLUTION: A distance A from a place, where a roller 103 for the push-pull chain 10 of a lower guide section 213 in a guide member 210 is received from the lower side, to an interior wall on the lower side of a hollow section 211 is made larger than a distance B from a place, where the lower guide member 213 is received from the lower side, to the lower edge of a plate 102. Consequently, the lower edge of the plate of the push-pull chain 10 is not received by the interior wall on the lower side of the hollow section 211, and the roller 103 for the push-pull chain 10 is received particularly from the lower side by the lower guide section 213 and guided rotatably. The guide member 210 also functions as the holding member of a tube cover, the roller 103 for the push-pull chain 10 is received to both upper-lower guide sections 212, 213 and rolled in the contraction-extension process of an automatic expansion type gate door, and the abrasion resistance of the guide member 210 is improved. |
