Full bore deflection drilling apparatus

Claim 1

A FULL BORE DEFLECTION DRILLING APPARATUS FOR INSERTION IN A STRING OF DRILL PIPE, COMPRISING, IN COMBINATION: AN UPPER PIPE SECTION FOR CONNECTION TO SAID DRILL PIPE; A MANDREL HAVING ONE END ADAPTED TO BE TELESCOPED WITHIN THE LOWER END OF SAID UPPER PIPE SECTION; MEANS FOR CONNECTING THE OTHER END OF SAID MANDREL TO A DRILLING MEANS, SAID FIRST MENTIONED MEANS PREVENTING DOWNWARD LONGITUDINAL MOVEMENT OF SAID MANDREL RELATIVE TO SAID DRILLING MEANS; A PAD ACTUATING SLEEVE SURROUNDING SAID MANDREL AND MOUNTED FOR LONGITUDINAL MOVEMENT RELATIVE TO SAID MANDREL; CONNECTING MEANS CONNECTING THE UPPER END OF SAID PAD ACTUATING SLEEVE TO THE LOWER END OF SAID UPPER PIPE SECTION; A PAD MEMBER COUPLED TO SAID SLEEVE FOR LATERAL MOVEMENT IN A DIRECTION NORMAL TO THE AXIS OF SAID PAD ACTUATING SLEEVE AND MANDREL; GUIDE MEANS BETWEEN SAID MANDREL AND PAD MEMBER, SAID GUIDE MEANS LIMITING-RELATIVE LONGITUDINAL MOVEMENT THEREBETWEEN; AND A RETRACTING SPRING POSITIONED TO EXERT A FORCE ON SAID PAD ACTUATING SLEEVE RELATIVE TO SAID MANDREL, SAID PAD ACTUATING SLEEVE AND PAD MEMBER INCLUDING INCLINED COOPERATING SURFACES IN ENGAGEMENT WITH EACH OTHER AND FORMING AN ANGLE BETWEEN SAID AXIS AND THE NORMAL THERETO, WHEREBY DOWNWARD FORCE OF SAID DRILL PIPE STRING ON SAID PIPE SECTION TELESCOPES SAID PIPE SECTION OVER THE UPPER END OF SAID MANDREL AND LONGITUDINALLY SLIDES SAID PAD ACTUATING SLEEVE ALONG SAID MANDREL TO CAM SAID PAD MEMBER LATERALLY AWAY FROM SAID PAD ACTUATING SLEEVE TO AN EXPANDED POSITION, SAID RETRACTING SPRING RETRACTING SAID PAD MEMBER UPON CESSATION OF SAID DOWNWARD FORCE.