Hydraulically actuated orienting device

Claim 1

AN ORIENTING SUB FOR INSERTION IN A DRILL STRING FOR EARTH BORING OPERATIONS COMPRISING, AN OUTER TUBULAR MEMBER HAVING A BORE THERETHROUGH, A TUBULAR PISTON IN SAID BORE, AN EXTERNAL SHOULDER ON SAID PISTON HAVING A RECESS THEREIN, SEALING MEANS BETWEEN SAID PISTON AND THE WALLS OF SAID BORE ABOVE AND BELOW SAID EXTERNAL SHOULDER, SAID PISTON BEING MOVABLE AXIALLY IN SAID BORE, MEANS SECURING SAID PISTON AGAINST ROTATIONAL MOVEMENT, SPRING BIASING MEANS BETWEEN SAID PISTON AND SAID OUTER TUBULAR MEMBER BIASING SAID PISTON AGAINST THE INLET PRESSURE OF CIRCULATING FLUID IN SAID BORE, VALVE MEANS, A RESTRICTED OUTLET FROM SAID PISTON, AN UNRESTRICTED OUTLET FROM SAID PISTON, SAID EXTERNAL SHOULDER DEFINING A RACE, AND A MOVABLE WEIGHTED MEMBER CO-ACTING WITH SAID RACE TO HOLD SAID PISTON IN ITS SPRING BIASED POSITION WHEN SAID WEIGHTED MEMBER IS NOT IN A PREDETERMINED POSITION WITH RESPECT TO SAID RECESS, SAID PISTON MOVING TO A POSITION OPPOSITE SAID SPRING BIASED POSITION WHEN SAID WEIGHTED MEMBER IS IN A PREDETERMINED POSITION WITH RESPECT TO SAID RECESS TO CLOSE SAID VALVE MEANS THEREBY CLOSING FLOW OF CIRCULATING FLUID THROUGH SAID UNRESTRICTED OUTLET FROM SAID PISTON TO PRODUCE A NOTICEABLE INCREASE IN CIRCULATING FLUID PRESSURE TO INDICATE SAID WEIGHTED MEMBER IS IN SAID PREDETERMINED POSITION WITH RESPECT TO SAID RECESS.