Dual lid for closing coupled openings

Claim 1

In a dual lid assembly for closing first and second coupled openings, the lid assembly including a first lid for closing fluid-tight the first opening and a second lid for closing fluid-tight the second opening, the two lids being entirely separable from one another and each having a lid axis; lid connecting means for coupling fluid-tight the two lids to one another; first actuating means coupled to the lid connecting means for operating the lid connecting means by an externally-applied force; lid locking means for tightening the first lid to a wall defining the first opening; second actuating means coupled to the lid locking means for operating the lid locking means by an externally-applied force; the improvement comprising: a. a bearing unit attached fluid-tight to the first lid in the center thereof; b. a circumferential collar attached to said bearing unit, said circumferential collar being arranged at that side of said first lid which is oriented away from said first opening when said first lid is in position thereon; said circumferential collar projecting radially from said bearing unit with respect to the axis of said first lid; c. a centering hub arranged in alignment with and displaceable parallel to the axis of said second lid; d. hub supporting means attached to said centering hub and secured to said second lid; e. means defining a circumferential channel provided in said centering hub; and f. a plurality of clamps movably supported on said second lid; each clamp having an actuating portion projecting into said channel for moving said clamps into operative and inoperative positions by respective opposite axial motions of said centering hub; each clamp having a claw portion spaced from the respective actuating portion; in said operative position said clamps engaging, with their claw portion, behind said circumferential collar for securing said first and second lids to one another.