| 摘要 |
PURPOSE:To prevent air leakage for measurement, by providing a member, which opens and closes the air passage and is displaced by air pressure, in the opening part of the air passage provided independently of the air enclosing port. CONSTITUTION:Enclosing tool 2 having air enclosing port 4 is provided in air cushion main body 1 and is connected to main body 1 through air passage 5. Further, independent air passage 5' is provided in the extension part of air passage 5 and is opened and closed by valve 10 provided in rubber bellows 9. Valve 10 is caused to adhere to cylindrical cover 11 through bellows 9 and cylindrical cover 11 keeps still in the position where air pressure and compressing spring 18 provided between projection 14 of cylindrical cover 11 and guide 13 are balanced. Therefore, if mark indication 22 is added to the cylindrical cover as shown in the figure and projection 14 can be slided to long hole 16 and detaining hole 17 of the pressing metal fitting provided in the interior of guide 13, air pressure is measured only by rotating cylindrical cover 11 from detaining hole 17 to long hole 16 as required. |
