Grain tank extension and signal device

Claim 1

IN A COMBINE HAVING AN ELEVATED GRAIN TANK WITH OPPOSED UPRIGHT SIDE AND END WALLS TERMINATING IN AN UPPER FLANGE EDGE FORMING AN UPWARDLY FACING SURFACE EXTENDING AROUND AND DEFINING AN OPEN TOP OF THE TANK, THE IMPROVEMENT OF WHICH COMPRISES: (A) AN EXTENSION AND CLOSURE STRUCTURE FOR ASSEMBLY ON SAID UPPER FLANGED END OF SAID GRAIN TANK, (B) SAID EXTENSION AND CLOSURE STRUCTURE HAVING OPPOSED SIDE AND END WALLS TERMINATING IN A LOWER EDGE WITH A DOWNWARDLY FACING SURFACE FOR SECURING IN GRAINTIGHT ENGAGED RELATION TO THE UPPER SURFACE OF THE WALLS OF THE GRAIN TANK WHEREBY SAID SIDE AND END WALLS OF THE EXTENSION AND CLOSURE STRUCTURE EXTEND UPWARDLY FROM CORRESPONDING SIDE AND END WALLS OF THE GRAIN TANK, (C) A GENERALLY HORIZONTAL TOP WALL CONNECTED TO SAID EXTENSION STRUCTURE SIDE AND END WALLS AT UPPER ENDS THEREOF AND UPWARDLY SPACED FROM SAID DOWNWARDLY FACING SURFACES TO DEFINE THE HEIGHT OF THE EXTENSION STRUCTURE AND INCREASE CAPACITY OF THE EXTENDED GRAIN TANK, SAID TOP WALL CLOSING THE EXTENSION STRUCTURE AND HAVING AN ACCESS OPENING THEREIN, LIPS EXTENDING UPWARDLY ON SAID TOP WALL AND DEFINING SAID ACCESS OPENING, (D) AND A DOOR HINGED ON SAID TOP WALL AT ONE SIDE OF SAID ACCESS OPENING AND SWINGABLE FROM OPEN TO CLOSED POSITIONS, SAID DOOR HAVING MARGINS ENGAGING PORTIONS OF SAID TOP WALL LIPS DEFINING THE ACCESS OPENING WHEN THE DOOR IS IN CLOSED POSITION.