Expansible subsurface well bore apparatus

Claim 1

A SUBSURFACE WELL BORE APPARATUS COMPRISING: (A) A TUBULAR BODY ADAPTED TO BE SECURED TO A DRILL STRING AND HAVING A CENTRAL PASSAGE; (B) A PLURALITY OF EXPANSIBLE ARMS SECURED TOP THE TUBULAR BODY AND ADAPTED TO OCCUPY A RETRACTED POSITION AND AN EXPANDED POSITION; (C) SLIDABLE MEANS MOVABLE WITHIN THE PASSAGE RESPONSIVE TO CHANGES IN PRESSURE OF A FLUID PASSING THROUGH THE PASSAGE TO ENGAGE THE PLURALITY OF EXPANSIBLE ARMS TO MOVE THEM TO AN EXPANDED POSITION; (D) ORIFICE-FORMING MEANS WITHIN THE PASSAGE; (E) CONSTRICTING MEANS DISPOSED RELATIVE TO THE ORIFICEFORMING MEANS; (F) THE ORIFICE-FORMING MEANS AND THE CONSTRICTING MEANS BEING SHAPED TO PROVIDE A FIRST ORIFICE AREA AND A SECOND LARGER ORIFICE AREA WHEN THE EXPANSIBLE ARMS ARE IN A RETRACTED POSITION; AND (G) THE SLIDABLE MEANS INCLUDING MEANS WHEREBY MOVEMENT OF THE SLIDABLE MEANS MOVES THE ORIFICE-FORMING MEANS AND THE CONSTRICTING MEANS RELATIVE TO EACH OTHER TO PROVIDE ONLY THE SECOND LARGER ORIFICE AREA