| 摘要 |
PROBLEM TO BE SOLVED: To easily provide an air duct with no trouble of air leakage on a lower surface of a trough. SOLUTION: It is furnished with a trough 2 on an upper surface of which an endless belt 1 floats and travels, a pipe type air duct 3 to deliver compressed air to float the endless belt 1 and a hollow screw 4 on which an axially central blowhole 5 is drilled and is constituted to screw and connect the air duct 3 by the hollow screw 4 along the lengthy direction of a lower surface of the trough 2 and to communicate the inside of the air duct 3 and the upper surface of the trough 1 to each other through the blowhole 5 of the hollow screw 4.
|
