Rotary safety joint

Claim 1

A SAFETY JOINT FOR USE IN THE DRILLING OF OIL WELLS, COMPRISING: (A) A TUBULAR BOX SECTION HAVING A PASSAGEWAY THERETHROUGH AND TERMINATING AT ONE END IN A THREADED BOX FOR THREADABLE RECEPTION OF THE PIN OF AN ADJACENT END OF A DRILL STRING; (B) A SHALLOW ANGLE INTERNAL, BUTTRESS-TYPE, HELICAL THREAD EXTENDING A LIMITED DISTANCE IN THE PASSAGEWAY IN SAID BOX SECTION AND SPACED FROM THE BOX; (C) A SEAL RING IN SAID PASSAGEWAY PORTION ADJACENT THE THREADED BOX; (D) SEALING MEANS BETWEEN SAID SEAL RING AND THE INNER WALL OF SAID PASSAGEWAY PORTION; (E) MEANS LIMITING MOVEMENT OF SAID SEAL RING TOWARD SAID BOX; (F) A THRUST WASHER IN SAID PASSAGEWAY SPACED LONGITUDINALLY THEREOF FROM SAID SEAL RING AT THE OPPOSITE SIDE THEREOF FROM SAID BOX; (G) REMOVABLE MEANS IN SAID PASSAGEWAY LIMITING LONGITUDINAL MOVEMENT OF SAID THRUST WASHER IN A DIRECTION AWAY FROM SAID SEAL RING; (H) A PLURALITY OF BELLEVILLE SPRINGS BETWEEN SAID SEAL RING AND THRUST WASHER; (I) A TUBULAR PIN SECTION HAVING A PASSAGEWAY THERETHROUGH AND INCLUDING (A) A BODY OF SUBSTANTIALLY THE SAME EXTERNAL DIAMETER AS THE EXTERNAL DIAMETER OF THE BOX SECTION; (J) A THREADED PIN AT ONE END OF THE BODY; (K) A REDUCED DIAMETER PORTION EXTENDING FROM THE OPPOSITE END OF THE BODY AND SLIDABLY RECEIVED IN AN ADJACENT END PORTION OF THE PASSAGEWAY OF THE BOX SECTION OPPOSITE THE BOX; (L) AN EXTERNALLY THREADED PART EXTENDING AXIALLY FROM THE REDUCED DIAMETER PART OF THE PIN SECTION, (A) THE THREADS OF SAID THREADED PART CORRESPONDING TO THE BUTTRESS THREADS OF THE BOX SECTION AND THREADABLY DISPOSED THEREIN; (M) AN INTERNALLY THREADED COLLAR EXTENDING AXIALLY FROM THE END OF THE THREADED PART OPPOSITE THE BODY, (A) SAID COLLAR ENGAGING THE THRUST WASHER TO FURTHER COMPRESS THE BELLEVILLE SPRINGS; (N) A WASH PIPE, (A) SAID WASH PIPE HAVING ONE END REMOVABLY CONNECTED TO SAID COLLAR, (B) AND EXTENDING THROUGH SAID THRUST WASHER, BELLEVILLE SPRINGS AND SEAL RINGS; (O) A SEALING MEANS BETWEEN THE SEAL RING AND SAID WASH PIPE; (P) THREE HELICAL SHOULDERS AT THE BASE OF THE REDUCED DIAMETER PART OF THE PIN SECTION ABOVE THE BODY, (A) SAID SHOULDERS EXTENDING 120* EACH, (B) AND HAVING THE SAME HELICAL LEAD AS THE BUTTRESS THREADS OF THE BOX SECTION AND PIN SECTION, (C) THERE BEING LONGITUDINALLY EXTENDING ABUTMENT SURFACES BETWEEN THE UPPER AND LOWER ADJACENT ENDS OF SAID SHOULDERS; (Q) AND CORRESPONDING HELICAL SHOULDERS AND ABUTMENT SURFACES AT THE ADJACENT END OF SAID BOX SECTION, (A) SAID SHOULDERS OF THE PIN SECTION BEING OUT OF ENGAGEMENT WITH THE RESPECTIVE SHOULDERS OF THE BOX SECTION WHEN THE SECTIONS ARE SCREWED TOTOGETHER, AND THE JOINT IS IN TENSION; (B) AND THE ABUTMENT SURFACES OF THE PIN SECTION BEING IN ABUTTING RELATIONSHIP WITH RESPECTIVE CORRESPONDING SURFACES OF THE BOX SECTION.