Reaming apparatus

Claim 1

A SIDE WALL ROLLER REAMER COMPRISING: A TUBULAR MEMBER HAVING MEANS AT ITS UPPER END FOR CONNECTING THE MEMBER TO A ROTARY DRILL STRING WHEREBY THE REAMER CAN BE ROTATED ABOUT THE AXIS OF SAID TUBULAR MEMBER WHICH THUS FORMS THE REAMER AXIS AND MEANS AT ITS LOWER END FOR CONNECTING THE MEMBER TO A ROTARY DRILL STRING WHEREBY TORQUE AND FLUID CAN BE TRANSMITTED BY THE REAMER FROM SUCH DRILL STRING AT THE UPPER END OF THE REAMER TO SUCH DRILL STRING AT THE LOWER END OF THE REAMER TO ROTATE A DRILL BIT CONNECTED TO THE LOWER END OF THE LAST MENTIONED DRILL STRING, A PLURALITY OF ROLLERS DISPOSED AROUND THE OUTER PERIPHERY OF SAID TUBULAR MEMBER, MEANS MOUNTING EACH OF SAID ROLLERS ON SAID MEMBER FOR ROTATION ABOUT AN AXIS WHICH THUS FORMS THE ROLLER AXIS, SAID ROLLER AXES BEING PARALLEL TO THE REAMER AXIS, EACH ROLLER HAVING AN OUTER SURFACE THAT IS A SURFACE OF REVOLUTION WITH RESPECT TO THE ROLLER AXIS, EACH ROLLER BEING LARGER IN DIAMETER AT ITS UPPER END THAN AT ITS LOWER END PROVIDING AN OUTER SURFACE HAVING PORTIONS OF INCREASING RADIUS PROGRESSING UPWARDS ALONG THE ROLLER, EACH ROLLER INCLUDING A PLURALITY OF CYLINDRICAL APERTURES IN ITS OUTER SURFACE DISPOSED AROUND THE PERIPHERY THEREOF WITH THEIR CYLINDRICAL AXES PERPENDICULAR TO THE ROLLER AXIS, A NUMBER OF SAID APERTURES BEING DISPOSED IN AN ANNULAR ROW AROUND EACH ROLLER NEAR THE UPPER END THEREOF, A GENERALLY CYLINDRICAL INSERT DISPOSED IN EACH OF SAID APERTURES, EACH INSERT INCLUDING A PORTION AT ONE END PROTRUDING FROM THE APERTURE AND FORMING A TIP ADAPTED TO CONTACT THE SIDEWALL OF A BORE HOLE, EACH INSERT IN THE APERTURES BELOW SAID ANNULAR ROW OF APERTURES PROTRUDING A DISTANCE SUCH THAT THE DISTANCE OF ITS TIP FROM THE ROLLER AXIS MEASURED PERPENDICULAR TO THE ROLLER AXIS IS AT LEAST AS GREAT AS THE DISTANCE FROM THE ROLLER AXIS OF THE PORTION OF THE OUTER SURFACE OF THE ROLLER ADJACENT THE APERTURE NEAREST THEREABOVE, AND EACH INSERT IN THE APERTURES IN SAID ANNULAR ROW OF APERTURES EQUALLY PROTRUDING FROM ITS APERTURE TO PLACE ITS TIP AT A DISTANCE (B) FROM THE ROLLER AXIS, SAID DISTANCE (B) BEING GREATER THAN THE MAXIMUM DISTANCE (R) FROM THE ROLLER AXIS OF THE TIPS OF INSERTS IN APERTURES BELOW SAID ROW, THE LAST SAID DISTANCE (R) ADDED TO THE DISTANCE (A) OF THE ROLLER AXIS FROM THE REAMER AXIS CONSTITUTING THE ON-GAGE RADIUS RGAGE OF THE REAMER ADAPTED TO REAM THE BORE HOLE TO THE SAME RADIUS AS THE ONGAGE RADIUS OF A NEW DRILL BIT CONNECTED TO A DRILL STRING BELOW THE REAMER,