Self-propelled and self-levelling open trench caisson

Claim 1

A SELF-PROPELLED AND SELF-LEVELLING CAISSON FOR AN OPEN PIPELINE TRENCH INCLUDING A PAIR OF REINFORCED SIDE WALLS, CROSS BARS ADJUSTABLY SECURING SAID WALLS IN PARALLEL VERTICAL PLANES SPACED APART A DISTANCE CORRESPONDING APPROXIMATELY TO THE WIDTH OF THE TRENCH, A PAIR OF HYDRAULIC CYLINDER ASSEMBLIES MOUNTED ON THE INSIDE OF SAID SIDE WALLS RESPECTIVELY, A TRANSVERSELY EXTENDING MOVABLE THRUST BAR, GUIDE WAYS FOR THE ENDS OF THE THRUST BAR IN SAID SIDE WALLS RESPECTIVELY AND LOCATED IN THE SAME HORIZONTAL PLANE WITH SAID HYDRAULIC CYLINDER ASSEMBLIES, THE ENDS OF SID THRUST BAR SLIDABLE IN SAID GUIDE WAYS AND CONNECTED WITH THE PISTON RODS OF SAID CYLINDER ASSEMBLIES RESPECTIVELY, SAID CYLINDER ASSEMBLIES AND SAD THRUST BAR POSITIONED AT SUCH HEIGHT ABOVE THE BOTTOM OF SAID SIDE WALLS THAT SAID THRUST BAR WILL EXTEND ACROSS THE END OF THE PIPELINE IN THE TRENCH WITHIN THE CAISSON WHEN SAID CAISSON IS POSITIONED IN THE TRENCH, WHEREBY THE FORCIBLE MOVEMENT OF SID THRUST BAR AGAINST THE END OF EACH PIPE SECTION AS SUCH SECTION IS ADDED TO THE PIPELINE WITHIN SAID CAISSON WILL CAUSE SAID CAISSON TO BE MOVED FORWARDLY IN THE TRENCH, A PAIR OF SHOE RUNNERS SUPPORTING THE FORWARD END OF SAID CAISSON AND ADAPTED TO SLIDE ALONG ON THE BOTTOM OF THE TRENCH, ADJUSTABLE FLEXIBLE MOUNTING MEANS ON SAID CAISSON FOR SAID SHOE RUNNERS, SAID MOUNTING MEANS INCLUDING HYDRAULIC CYLINDERS FOR RAISING OR LOWERING ECH SHOE RUNNER INDEPENDENTLY, AND A POWER PLANT ON SAID CAISSON WITH CONTROLS FOR SAID FIRST MENTIONED CYLINDER ASSEMBLIES AND FOR SAID LAST MENTIONED HYDRAULIC CYLINDERS.