Offshore drilling platform

Claim 1

IN AN OFFSHORE DRILLING RIG, THE COMBINATION COMPRISING A BUOYANT HULL, A DECK FIXED TO THE HULL FOR SUPPORTING A DRILLING RIG, A PLURALITY OF LEG GUIDES FASTENED TO THE HULL, THE GUIDES EACH INCLUDING AN OPENWORK STRUCTURE WITH AN UPPER RECTANGULAR FRAMEWORK RIGIDLY ATTACHED TO THE DESK BY DEPENDING COLUMN MEMBERS AND A LOWER RECTANGULAR FRAMEWORK IN VERTICALLY SLIDING CONNECTION WITH THE VERTICAL COLUMNS, A JACK POSITIONED BETWEEN AND CONNECTED TO THE UPPER AND LOWER FRAMEWORKS FOR MOVING THE LOWER FRAMEWORK TOWARD AND AWAY FROM THE UPPER FRAMEWORK, LEGS GUIDINGLY SUPPORTED THROUGH THE OPENWORK STRUCTURE AND SURROUNDED BY THE UPPER AND LOWER FRAMEWORKS OF THE GUIDE FRAME, RIBS ATTACHED ALONG THE LENGTH OF EACH LEG AND PARALLEL WITH THE LEG AXIS, EACH RIB HAVING SLOTTED OPENING EXTENDING HORIZONTALLY AND SPACED VERTICALLY ALONG THE LENGTH OF THE RIBS, A CHOCK ATTACHED TO THE GUIDE WITH FLANGES IN RELATIVE SLIDING ENGAGEMENT WITH THE RIBS AND HAVING ALIGNED SPACED OPENINGS EXTENDING HORIZONTALLY, THE CHOCK OPENINGS BEING IN ALIGNMENT WITH THE SLOTTED OPENINGS OF THE RIBS, PINS PASSED THROUGH THE SLOTTED OPENINGS OF THE RIBS AND OF A LENGTH GREATER THAN THE WIDTH OF THE LOWER FRAMEWORK OF THE GUIDE WHEREBY THE LOWER FRAMEWORK IS SUPPORTED ON THE PINS FOR ELEVATION OF THE UPPER FRAMEWORK AND DECK UPON EXTENSION OF THE JACK, THE PINS BEING INSERTED INTO THE OPENINGS OF THE CHOCKS AND ALIGNED SLOTTED OPENINGS OF THE RIBS FOR FIXING THE LOCATION OF THE GUIDE ON THE RIBS OF THE LEG WHEN PINS ARE REMOVED FROM SUPPORTING POSITION BENEATH THE LOWER