| 摘要 |
<p>PURPOSE: To operate a door against large fluid pressure under small force by fixing an inner door coaxially with a main door, pivotally moving the inner door to a second position displaced from a first position on a plane flush with the opening of the main door and driving the main door after the inner door pivotally moves beyond the second position. CONSTITUTION: A main door 14 provided with an opening 18 which can be screened by a small inner door 20 and the inner door 20 are coaxially mounted on a pivot shaft 12. The pivot shaft 12 pivotally moves so that only the inner door 20 is first pivotally moved to open a relief opening and reduce air pressure exerted upon the main door 14. Subsequently, when the pivot shaft 12 is pivotally moved beyond a predetermined angle, driving means including the mutually cooperating parts 30 and 32 of the inner door 20 and the main door 14 engage to open the main door 14 subsequent to the opening of the inner door 20. Thus, force for opening the main door can be reduced more than a case in which a single door having no inner door with the same dimension is opened against fluid pressure.</p> |
