摘要 |
The present invention provides apparatus which operates the door of a chamber that is capable of maintaining pressure within the chamber. The invention includes an improved closure for cooperating to move the door among positions in which it confronts the opening of the chamber, seals the chamber and allows access to the interior of the chamber. The preferred embodiment of the present invention includes a driving member and an operating member which have surfaces which cooperate to move the operating member in two separate directions. Movement of the operating member in the first direction secures the door in its position in which it confronts the chamber opening but in which it cannot seal the chamber. Movement of the operating member in the second direction causes the door to be secured against the perimeter of the chamber opening, thus sealing the chamber against fluid flow from between the perimeter opening and the door. Further, the present invention can include apparatus for preventing the door from assuming its sealed position until the door is prevented from swinging away from the chamber opening, thus preventing inadvertent pressure buildup within the chamber.
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