Pressure vessel with hatch

Claim 1

A pressure vessel comprising a hatch movable between a locked position in which it seals an opening in the pressure vessel, and an open position in which it at least partly exposes the pressure vessel opening and makes the interior of the pressure vessel accessible, said hatch being movable in two directions sequential to each other and mutually at least substantially perpendicular, of which one direction substantially coincides with the geometric axis of the pressure vessel opening and the other at least generally extends laterally of the opening, said hatch having for said movement in said two directions a plurality of eccentrically mounted cam members, which are joined to each other for common pivotal movements between two end positions in planes perpendicular to the plane of the hatch, are provided and are in engagement with a guide means in front of the hatch and extending to one side of the pressure vessel opening, are at one of their pivotal end positions reciprocally displaceable laterally of the opening together with the hatch while carrying the hatch in said guide means, are at the other of their pivotal end positions engageable against the hatch with support in the guide means for inserting into and locking the hatch against the pressure vessel opening and for displacing the hatch reciprocally in the direction at least substantially coinciding with the geometrical axis of the pressure vessel opening during their pivotal movements between said both pivotal end positions, and are each provided with a roller mounted eccentrically on them for rotation, which rollers in one pivotal end position of the cam members constitute running wheels in the guide means and in the vicinity of the other pivotal end position constitute cam surfaces on said cam members but are unloaded in the locked position of the hatch by said support of said cam members in the guide means, so that the excess pressure in the vessel does not act on said rollers but is instead taken up by said cam members.