Retractable drill bits

Claim 2

Retrievable drill bit apparatus adapted to be moved longitudinally through a tubular drilling string disposed in a borehole: an outer structure adapted to be secured to the drilling string and including a drive mandrel; cutter means comprising a plurality of expandable and retractable cutters; a carrier supporting said cutter means and in telescopic relation thereto, said carrier supporting said cutter means with said cutters in a fully retracted position for movement within the drilling string and mandrel; coengageable coupling means on said mandrel and cutters for securing said cutters to said mandrel with said cutters in expanded position; nd coengageable orienting means on said cutter means and outer structure to orient said cutters for simultaneous lateral outward expansion from fully retracted position into coupled relation to said mandrel; said carrier being movable downwardly of said cutter means to a position retaining said cutters expanded outwardly and coupled to said mandrel.

Claim 3

Retrievable drill bit apparatus adapted to be moved longitudinally through a tubular drilling string disposed in a borehole: an outer structure adapted to be secured to the drilling string and including a drive mandrel; cutter means comprising a plurality of expandable and retractable cutters; a carrier supporting said cutter means and in telescopic relation thereto; coengageable coupling means on said mandrel and cutters for securing said cutters to said mandrel with said cutters in expanded position; and coengageable orienting means on said cutter means and outer structure to orient said cutters for simultaneous lateral outward expansion into coupled relation to said mandrel; said carrier being movable downwardly of said cutter means to a position retaining said cutters expanded outwardly and coupled to said mandrel; said coengageable orienting means also limiting downward movement of said cutter means in said outer structure.

Claim 4

Retrievable drill bit apparatus adapted to be moved longitudinally through a tubular drilling string disposed in a borehole: an outer structure adapted to be secured to the drilling string and including a drive mandrel; cutter means comprising a plurality of expandable and retractable cutters; a carrier supporting said cutter means and in telescopic relation thereto; coengageable coupling means on said mandrel and cutters for securing said cutters to said mandrel with said cutters in expanded position; and coengageable orienting means on said cutter means and outer structure to orient said cutters for simultaneous lateral outward expansion into coupled relation to said mandrel; said carrier being movable downwardly of said cutter means to a position retaining said cutters expanded outwardly and coupled to said mandrel; said coengageable orienting means also limiting downward movement of said cutter means in said outer structure.

Claim 5

Retrievable drill bit apparatus adapted to be moved longitudinally through a tubular drilling string disposed in a borehole: an outer structure adapted to be secured to the drilling string and including a drive mandrel; cutter means comprising a plurality of expandable and retractable cutters; a carrier supporting said cutter means and in telescopic relation thereto; coengageable coupling means on said mandrel and cutters for securing said cutters to said mandrel with said cutters in expanded position; and coengageable orienting means on said cutter means and outer structure to orient said cutters for simultaneous lateral outward expansion into coupled relation to said mandrel; said carrier being movable downwardly of said cutter means to a position retaining said cutters expanded outwardly and coupled to said mandrel; said cutter means including an upper cam sleeve having said orienting means thereon, circumferentially spaced laterally shiftable arms secured to and depending from said sleeve, the lower portions of said arms being secured to said cutter.

Claim 6

Retrievable drill bit apparatus adapted to be moved longitudinally through a tubular drilling string disposed in a borehole: an outer structure adapted to be secured to the drilling string and including a drive mandrel; cutter means comprising a plurality of expandable and retractable cutters; a carrier supporting said cutter means and in telescopic relation thereto; coengageable coupling means on said mandrel and cutters for securing said cutters to said mandrel with said cutters in expanded position; and coengageable orienting means on said cutter means and outer structure to orient said cutters for simultaneous lateral outward expansion into coupled relation to said mandrel; said carrier being movable downwardly of said cutter means to a position retaining said cutters expanded outwardly and coupled to said mandrel; said cutter means including an upper cam sleeve having said orienting means thereon, circumferentially spaced laterally shiftable arms secured to and depending from said sleeve, the lower portions of said arms being secured to said cutter.

Claim 7

Retrievable drill bit apparatus as defined in claim 3; said coengageable orienting means limiting downward movement of said cutters and locating said cutters for lateral expansion into coupling engagement with said mandrel.

Claim 8

Retrievable drill bit apparatus as defined in claim 3; said coengageable orienting means limiting downward movement of said cutters and locating said cutters for lateral expansion into coupling engagement with said mandrel, said mandrel having longitudinal grooves into which said arms move upon lateral outward expansion of said arms and cutters.

Claim 9

Retrievable drill bit apparatus as defined in claim 3; said arms having longitudinal slots; said carrier having keys slidable in said slots and engageable with said cam sleeve at the upper ends of said slots to elevate said cutter means in said outer structure and upwardly through the drilling string.

Claim 10

Retrievable drill bit apparatus as defined in claim 3; said coengageable orienting means limiting downward movement of said cutters and locating said cutters for lateral expansion into coupling engagement with said mandrel; said arms having longitudinal slots; said carrier having keys slidable in said slots and engageable with said cam sleeve at the upper ends of said slots to elevate said cutter means in said outer structure and upwardly through the drilling string.

Claim 11

Retrievable drill bit apparatus as defined in claim 3; said coengageable orienting means limiting downward movement of said cutters and locating said cutters for lateral expansion into coupling engagement with said mandrel; said arms having longitudinal slots; said carrier having keys slidable in said slots and engageable with said cam sleeve at the upper ends of said slots to elevate said cutter means in said outer structure and upwardly through the drilling string; said mandrel having longitudinal grooves into which said arms move upon lateral outward expansion of said arms and cutters.

Claim 12

Retrievable drill bit apparatus as defined in claim 3; said arms having longitudinal slots; said carrier having keys slidable in said slots and engageable with said cam sleeve at the upper ends of said slots to elevate said cutter means in said outer structure and upwardly through the drilling string; said carrier projecting laterally inwardly of said cutters to drill an inner portion of the borehole when disposed in its position retaining said cutters laterally outwardly.

Claim 13

Retrievable drill bit apparatus as defined in claim 1; said cutters being in circumferential overlapping relation when retracted within said mandrel.

Claim 14

Retrievable drill bit apparatus as defined in claim 3; said coengageable orienting means limiting downward movement of said cutters and locating said cutters for lateral expansion into coupling engagement with said mandrel; said cutters being in circumferential overlapping relation when retracted within said mandrel.

Claim 15

Retrievable drill bit apparatus as defined in claim 3; said arms having longitudinal slots; said carrier having keys slidable in said slots and engageable with said cam sleeve at the upper ends of said slots to elevate said cutter means in said outer structure and upwardly through the drilling string; said cutters being in circumferential overlapping relation when retracted within said mandrel.

Claim 16

Retrievable drill bit apparatus adapted to be moved longitudinally through a tubular drilling string disposed in a borehole: an outer structure adapted to be secured to the drilling string and including a drive mandrel; cutter means comprising a plurality of expandable and retractable cutters; a carrier supporting said cutter means and in telescopic relation thereto; said mandrel having circumferentially spaced slots opening to the exterior of said mandrel and into which said cutters are expandable; and coengageable orienting means on said cutter means and outer structure to orient said cutters in alignment with said slots for outward expansion thereinto and in coupling relation to saId mandrel; said carrier being movable downwardly of said cutter means to a position behind said cutters to retain said cutters outwardly in said slots and coupled to said mandrel and with the cutters extending through the slots beyond the periphery of said mandrel.

Claim 17

Retrievable drill bit apparatus adapted to be moved longitudinally through a tubular drilling string disposed in a borehole: an outer structure adapted to be secured to the drilling string and including a drive mandrel; cutter means comprising a plurality of expandable and retractable cutters; a carrier supporting said cutter means and in telescopic relation thereto; said mandrel having circumferentially spaced slots opening to the exterior of said mandrel and into which said cutters are expandable; and coengageable orienting means on said cutter means and outer structure to orient said cutters in alignment with said slots for outward expansion thereinto and in coupling relation to saId mandrel; said carrier being movable downwardly of said cutter means to a position behind said cutters to retain said cutters outwardly in said slots and coupled to said mandrel and with the cutters extending through the slots beyond the periphery of said mandrel.

Claim 18

Retrievable drill bit apparatus adapted to be moved longitudinally through a tubular drilling string disposed in a borehole: an outer structure adapted to be secured to the drilling string and including a drive mandrel; cutter means comprising a plurality of expandable and retractable cutters; a carrier supporting said cutter means and in telescopic relation thereto; said mandrel having circumferentially spaced slots into which said cutters are expandable; and coengageable orienting means on said cutter means and outer structure to orient said cutters in alignment with said slots for outward expansion thereinto and in coupling relation to said mandrel; said carrier being movable downwardly of said cutter means to a position behind said cutters to retain said cutters outwardly in said slots and coupled to said mandrel; said coengageable orienting means also limiting downward movement of said cutter means in said outer structure.

Claim 19

Retrievable drill bit apparatus adapted to be moved longitudinally through a tubular drilling string disposed in a borehole: an outer structure adapted to be secured to the drilling string and including a drive mandrel; cutter means comprising a plurality of expandable and retractable cutters; a carrier supporting said cutter means and in telescopic relation thereto; said mandrel having circumferentially spaced slots into which said cutters are expandable; and coengageable orienting means on said cutter means and outer structure to orient said cutters in alignment with said slots for outward expansion thereinto and in coupling relation to said mandrel; said carrier being movable downwardly of said cutter means to a position behind said cutters to retain said cutters outwardly in said slots and coupled to said mandrel; said coengageable orienting means also limiting downward movement of said cutter means in said outer structure.

Claim 20

Retrievable drill bit apparatus adapted to be moved longitudinally through a tubular drilling string disposed in a borehole: an outer structure adapted to be secured to the drilling string and including a drive mandrel; cutter means comprising a plurality of expandable and retractable cutters; a carrier supporting said cutter means and in telescopic relation thereto; said mandrel having circumferentially spaced slots into which said cutters are expandable; and coengageable orienting means on said cutter means and outer structure to orient said cutters in alignment with said slots for outward expansion thereinto and in coupling relation to said mandrel; said carrier being movable downwardly of said cutter means to a position behind said cutters to retain said cutters outwardly in said slots and coupled to said mandrel; said cutter means including an upper cam sleeve having said orienting means thereon, circumferentially spaced laterally shiftable arms secured to and depending from said sleeve, the lower portions of said arms being secured to said cutters.

Claim 21

Retrievable drill bit apparatus adapted to be moved longitudinally through a tubular drilling string disposed in a borehole: an outer structure adapted to be secured to the drilling string and including a drive mandrel; cutter means comprising a plurality of expandable and retractable cutters; a carrier supporting said cutter means and in telescopic relation thereto; said mandrel having circumferentially spaced slots into which said cutters are expandable; and coengageable orienting means on said cutter means and outer structure to orient said cutters in alignment with said slots for outward expansion thereinto and in coupling relation to said mandrel; said carrier being movable downwardly of said cutter means to a position behind said cutters to retain said cutters outwardly in said slots and coupled to said mandrel; said cutter means including an upper cam sleeve having said orienting means thereon, circumferentially spaced laterally shiftable arms secured to and depending from said sleeve, the lower portions of said arms being secured to said cutters.

Claim 22

Retrievable drill bit apparatus as defined in claim 15, said coengageable orienting means limiting downward movement of said cutters and locating said cutters for lateral expansion into said mandrel slots.

Claim 23

Retrievable drill bit apparatus as defined in claim 15, said coengageable orienting means limiting downward movement of said cutters and locating said cutters for lateral expansion into said mandrel slots; said mandrel having longitudinal grooves into which said arms move upon lateral outward expansion of said arms and cutters.

Claim 24

Retrievable drill bit apparatus as defined in claim 15; said arms having longitudinal slots; said carrier having keys slidable in said arm slots and engageable with said cam sleeve at the upper ends of said arm slots to elevate said cutter means in said outer structure and upwardly through the drilling string.

Claim 25

Retrievable drill bit apparatus as defined in claim 15, said coengageable orienting means limiting downward movement of said cutters and locating said cutters for lateral expansion into said mandrel slots; said arms having longitudinal slots; said carrier having keys slidable in said arm slots and engageable with said cam sleeve at the upper ends of said arm slots to elevate said cutter means in said outer structure and upwardly through the drilling string.

Claim 26

Retrievable drill bit apparatus as defined in claim 15, said coengageable orienting means limiting downward movement of said cutters and locating said cutters for lateral expansion into said mandrel slots; said arms having longitudinal slots; said carrier having keys slidable in said arm slots and engageable with said cam sleeve at the upper ends of said arm slots to elevate said cutter means In said outer structure and upwardly through the drilling string; said mandrel having longitudinal grooves into which said arms move upon lateral outward expansion of said arms and cutters.

Claim 27

Retrievable drill bit apparatus as defined in claim 13; said cutters being in circumferential overlapping relation when retracted within said mandrel.

Claim 28

Retrievable drill bit apparatus as defined in claim 15; said cutters being in circumferential overlapping relation when retracted within said mandrel.

Claim 29

Retrievable drill bit apparatus as defined in claim 3; said coengageable orienting means limiting downward movement of said cutters and locating said cutters for lateral expansion into coupling engagement with said mandrel, said mandrel having longitudinal grooves into which said arms move upon lateral outward expansion of said arms and cutters; said cutters being in circumferential overlapping relation when retracted within said mandrel; said outer structure having cam means engaged by said cutters upon elevation of said cutter means in said outer structure to orient said overlapping cutters with said longitudinal groove to permit passage of a portion of said cutters through said grooves.

Claim 30

Retrievable drill bit apparatus as defined in claim 15, said coengageable orienting means limiting downward movement of said cutters and locating said cutters for lateral expansion into said mandrel slots; said mandrel having longitudinal grooves into which said arms move upon lateral outward expansion of said arms and cutters; said cutters being in circumferential overlapping relation when retracted within said mandrel; said outer structure having cam means engaged by said cutters upon elevation of said cutter means in said outer structure to orient said overlapping cutters with said longitudinal grooves to permit passage of a portion of said cutters through said grooves.

Claim 31

Retrievable drill bit apparatus as defined in claim 3; said cutter means including an upper cam sleeve having said orienting means thereon, circumferentially spaced laterally shiftable arms secured to and depending from said sleeve, the lower portions of said arms being secured to said cutters; said arms having longitudinal slots; said carrier having keys slidable in said slots and engageable with said cam sleeve at the upper ends of said slots to elevate said cutter means in said outer structure and upwardly through the drilling string; said carrier having lugs projecting downwardly between said cutters when said carrier is disposed in its position retaining said cutters expanded outwardly.

Claim 32

Retrievable drill bit apparatus adapted to be moved longitudinally through a tubular drilling string disposed in a borehole: an outer structure adapted to be secured to the drilling string and including a drive mandrel; cutter means comprising a plurality of expandable and retractable cutters; a carrier supporting said cutter means and in telescopic relation thereto; said mandrel having circumferentially spaced slots into which said cutters are expandable; and coengageable orienting means on said cutter means and outer structure to orient said cutters in alignment with said slots for outward expansion thereinto and in coupling relation to said mandrel; said carrier being movable downwardly of said cutter means to a position behind said cutters to retain said cutters outwardly in said slots and coupled to said mandrel; said mandrel slots having upper circumferentially offset portions; said cutters having offset portions fitting snugly within said offset portions of said slots.

Claim 33

Retrievable drill bit apparatus adapted to be moved longitudinally through a tubular drilling string disposed in a borehole: an outer structure adapted to be secured to the drilling string and including a drive mandrel; cutter means comprising a plurality of expandable and retractable cutters; a carrier supporting said cutter means and in telescopic relation thereto; said mandrel having circumferentially spaced slots into which said cutters are expandable; and coengageable orienting means on said cutter means and outer structure to orient said cutters in alignment with said slots for outward expansion thereinto and in coupling relation to said mandrel; said carrier being movable downwardly of said cutter means to a position behind said cutters to retain said cutters outwardly in said slots and coupled to said mandrel; said mandrel slots having upper circumferentially offset portions; said cutters having offset portions fitting snugly within said offset portions of said slots.

Claim 34

Retrievable drill bit apparatus adapted to be moved longitudinally through a tubular drilling string disposed in a borehole: an outer structure adapted to be secured to the drilling string and including a drive mandrel; cutter means comprising a plurality of expandable and retractable cutters; a carrier supporting aid cutter means and in telescopic relation thereto, said carrier supporting said cutter means with said cutters in a fully retracted position for movement within the drilling string and mandrel; said mandrel having circumferentially spaced slots into which said cutters are expandable; and coengageable orienting means on said cutter means and outer structure to orient said cutters in alignment with said slots for simultaneous outward expansion thereinto from fully retracted position into coupling relation to said mandrel; said carrier being movable downwardly of said cutter means to a position behind said cutters to retain said cutters outwardly in said slots and coupled to said mandrel.

Claim 35

Retrievable drill bit apparatus adapted to be moved longitudinally through a tubular drilling string disposed in a borehole: an outer structure adapted to be secured to the drilling string and including a drive mandrel; cutter means comprising a plurality of expandable and retractable cutters; a carrier supporting aid cutter means and in telescopic relation thereto, said carrier supporting said cutter means with said cutters in a fully retracted position for movement within the drilling string and mandrel; said mandrel having circumferentially spaced slots into which said cutters are expandable; and coengageable orienting means on said cutter means and outer structure to orient said cutters in alignment with said slots for simultaneous outward expansion thereinto from fully retracted position into coupling relation to said mandrel; said carrier being movable downwardly of said cutter means to a position behind said cutters to retain said cutters outwardly in said slots and coupled to said mandrel.