Dual passage drilling stem having selfcontained valve means

Claim 1

IN A TOOL OPERATING STRING COMPRISING A PLURALITY OF SECTIONS CONNECTED IN END TO END RELATION SO AS TO EXTEND FROM AN OPERATING MEANS AT THE TOP OF A BORE TO A TOOL IN THE BORE, SAID STRING, INCLUDING SAID SECTIONS, HAVING DOWNFLOW AND UPFLOW PASSAGE MEANS FROM END TO END THEREOF: AT LEAST ONE OF SAID SECTIONS HAVING THEREIN A VALVE DEVICE FOR PREVENTING FLOW OF FLUID THROUGH SAID PASSAGE MEANS, SAID VALVE DEVICE COMPRISING INNER AND OUTER TUBULAR WALLS, THE SPACE BETWEEN SAID TUBULAR WALLS CONSTITUTING A DOWNFLOW PASSAGE AND THE INTERIOR OF SAID INNER TUBULAR WALL BEING AN UPFLOW PASSAGE, AN ANNULAR UPWARDLY CLOSING CHECK VALVE FOR SAID DOWNFLOW PASSAGE, A TRANSVERSELY POSITIONED PLUG VALVE IN SAID VALVE DEVICE FOR CLOSING SAID UPFLOW PASSAGE, AND MEANS EXPOSED TO THE EXTERIOR OF SAID OUTER TUBULAR WALL FOR MANUALLY OPERATING SAID PLUG VALVE TO PREVENT UPWARD FLOW THERETHROUGH.