摘要 |
<p>A door structure comprises: a first plate serving as fixed frame with an opening enclosed by a peripheral edge; and a door connected pivotally to this first plate by at least one hinge construction such that with its peripheral zone the door can co-act sealingly with said peripheral edge; which first plate carries a number of peripherally arranged clamps, which clamps are simultaneously rotatable by a collective operating mechanism with an operating handle and through rotation can co-act with the peripheral zones of corresponding non-round continuous holes in the door, which peripheral zones have for each clamp a contact surface inclining relative to the main plane of the door structure in the closed situation, which continuous holes have a form such that a clamp can pas therethrough. The door structure has the characteristic that the door comprises a second plate which is strengthened with at least one beam welded to this plate and extending between two clamps situated on either side of the door; the clamps are arranged symmetrically pairwise on rotation shafts; the continuous holes in the door are correspondingly formed slotted holes; each peripheral zone of a continuous hole in the door has two substantially symmeticaly located, inclining clamp contact surfaces.</p> |