Coupling with plural lug in slot holding means and external sealing shell

Claim 1

A PRESSURE VESSEL COMPRISING TWO SEPARABLE PARTS HAVING ALIGNED WALLS WHICH DEFINE A PAIR OF REGISTERING MOUTHS, THE WALL OF EACH OF THE PART OF THE VESSEL INCLUDING ADJACENT ITS MOUTH A THICKENED PORTION HAVING RECESSES FORMED IN ITS INTERNAL AND EXTERNAL SURFACES, THE THICKNESS OF SAID WALL AT THE BOTTOMS OF SAID RECESSES REMAINING SUBSTANTIALLY EQUAL TO THAT OF THOSE PORTIONS OF SAID WALL BEYOND SAID THICKENED PORTION, THE RECESSES IN THE TWO PORTIONS BEING POSITIONED OPPOSITE EACH OTHER AND EXTENDING IN A GENERALLY CIRCUMFERENTIAL DIRECTION, A PLURALITY OF PAIRS OF CLEATS, THE CLEATS OF EACH PAIR BEING DISPOSED ONE INSIDE AND THE OTHER OUTSIDE THE VESSEL, EACH CLEAT BEING FORMED WITH TWO PROJECTIONS ENGAGING RESPECTIVELY IN SAID RECESSED IN THE TWO PARTS OF THE VESSEL, A PLURALITY OF TIE MEMBERS WHICH PASS WITH CLEARANCE THROUGH THE VESSEL WALLS AND DRAW THE PAIRS OF CLEATS TOGETHER, SAID CLEATS AND TIE MEMBERS SECURING THE WALLS OF SAID TWO PARTS TOGETHER AGAINST FORCES ACTING IN A DIRECTION PERPENDICULAR TO THE PLANE OF THE MOUTHS AND FORMING A JOINT BETWEEN THE TWO PARTS OF SAID VESSEL, SAID JOINT BEING SO FLUID PERVIOUS AS TO BE SUBJECT TO THE SAME PRESSURE ON BOTH INSIDE AND OUT, AND A FLUID TIGHT SEALING SHELL MADE OF RELATIVELY THIN FLEXIBLE MATERIAL WHICH EXTENDS ACROSS AND SEALS SAID JOINT, SAID SEALING SHELL HAVING ITS CONCAVE FACE TOWARD THE VESSEL WALL AND ITS OPPOSITE EDGES SEALED FLUID TIGHT TO SAID VESSEL PARTS ALONG LINES LYING ON OPPOSITE SIDES OF SAID JOINT, THE MAXIMUM TRANSVERSE DIMENSION OF SAID SEALING SHELL BEING SUBSTANTIALLY SMALLER THAN THAT OF SAID MOUTHS.