Plastic valve bag

Claim 1

A PLASTIC BAG, COMPRISING TWO PAIRS OF OPPOSITELY FACING SIDE WALLS, A FIRST PAIR (58, 7, 3, 4, 5, 8) OF SAID TWO PAIRS OF SIDE WALLS HAVING A CONSTRUCTION AND SHAPE ADAPTED TO FORM OPPOSITELY FACING GUSSETS (3, 4, 5, 8) IN SAID SIDE WALLS WHEN SAID FIRST PAIR OF SIDE WALLS IN FOLDED FLATLY, A FIRST PAIR OF GUSSET BOTTOM WALL EXTENSIONS (6A) RESPECTIVELY INTEGRAL WITH OPPOSITE SIDES OF SAID FIRST PAIR OF SIDE WALLS AND EXTENDING TOWARDS EACH OTHER, A SECOND PAIR OF BOTTOM WALL EXTENSIONS RESPECTIVELY INTEGRAL WITH SAID OTHER PAIR OF SIDE WALLS (1, 2) EXTENDING TOWARDS EACH OTHER PAIR OF SIDE FIRST PAIR OF GUSSET BOTTOM WALL EXTENSIONS (6A), A FIRST WELDED SEAM (34) SEALING SAID FIRST AND SECOND PAIR OF BOTTOM WALL EXTENSIONS THEREBY FORMING A CLOSED BOTTOM WALL (59) IN SAID PLASTIC BAG WHEN THE LATTER IS FULL, A TOP WALL EXTENSION (6A) INTEGRAL WITH ONE SIDE OF SAID FIRST PAIR OF SIDE WALLS AND EXTENDING TOWARD THE OTHER WALL OF SAID FIRST PAIR OF SIDE WALLS, A TAPEZOIDALLY SHAPED CORNER PORTION (6) INTEGRAL WITH SAID OTHER WALL OF SAID FIRST PAIR OF SIDE WALLS, SAID CORNER PORTION BEING ADAPTED TO BE FOLDED FLATLY, A RECTANGULARLY SHAPED VALVE STRIP (69) OVERLYING SAID CORNER PORTION (19) SAID VALVE STRIP (69) INCLUDING A PLURALITY OF GROOVES (19) AT THE END OPPOSITE THE SIDE ADJACENT TO ONE GESSET SIDE WALL (58, 7) OF SAID TWO PAIRS OF SIDE WALLS, FIRST WELDING MEANS (11) CONNECTING SAID CORNER PORTION (6) TO THE CORRESPONDING OVERLYING VALVE STRIP (60), A PAIR OF TOP WALL EXTENSIONS (1'', 2) RESPECTIVELY INTEGRAL WITH OPPOSITE SIDES (1, 2) OF SAID OTHER PAIR OF SIDE WALLS AND WITH SAID CORNER PORTION (6) AND EXTENDING TOWARD EACH OTHER AND PARTIALLY EXTENDING OVER SAID TOP WALL EXTENSION (6A) SAID CORNER PORTION (6) AND SAID VALVE STRIP (60), SECOND WELDING MEANS (15, 16) SUBSTANTIALLY TRANSVERSE TO SAID FIRST WELDING MEANS (11), CONNECTING SAID VALVE STRIP TO SAID PAIR OF TOP WALL EXTENSIONS (1'', 2) AND A SECOND WELDED SEAM (33) SEALING SAID TOP WALL EXTENSIONS (1'', 2, 6A) AND OPPOSITE SIDES OF SAID VALVE STRIP (60) THEREBY FORMING A TOP WALL IN SAID PLASTIC BAG WHEN THE LATTER IS FULL, SAID VALVE STRIP (60) AND SECOND WELDED SEAM (33) DEFINING A VALVE INLET FOR FILLING SAID PLASTIC BAG.