| 摘要 |
A first element (11) of the support structure (10) able to rotate about the axis of rotation (A) is fixed to the door frame (9) in a vertical direction; a second element (12) is supported by the first element (11) in a manner rotatable about the axis (A) and movable vertically relative to the element (11); said element (12) is fixed to the door (1) to move vertically therewith; a first piston is slidable under sealed conditions within a first chamber filled with operating liquid and is rigid with the support element (11); a second piston (32) is slidable under sealed conditions within a second chamber (34) filled with operating liquid and is rigid with the support element (11); said chamber (33) communicates with the chamber (34) via a passage duct (35) such that compression of the chamber (33) produces expansion of the chamber (34), the expansion of the chamber (34) causing the second piston (32) to rise relative to the chamber (34); valve means (40) are also provided to automatically close the passage (35) for the operating liquid from the chamber (34) to the chamber, said passage being able to be opened by external control. <IMAGE> |
