Retractable drill bits

Claim 2

In an expansible and retractable drill bit for drilling a bore hole: tubular drive means attachable to the lower portion of a tubular drilling string; deflector means extending across the passage of said drive means; cutter means movable downwardly through the passage of said drive means and into engagement with said deflector means to be expanded thereby into driving relation to said tubular drive means and to a position extending laterally outwardly beyond the exterior of said drive means; said cutter meaNs being constructed and arranged to extend from a location closely adjacent to the axis of said tubular drive means to said extended position beyond said drive means to drill upon substantially the full cross-sectional area of the bottom of the bore hole upon being expanded into driving relation to said tubular drive means; and means for turning said cutter means within said drive means in response to downward movement of said cutter means in said drive means to orient said cutter means relative to said deflector means.

Claim 3

In a drill bit as defined in claim 1; and holding means in said drive means for retaining said cutter means in its outwardly expanded position.

Claim 4

In an expansible and retractable drill bit for drilling a bore hole: tubular drive means attachable to the lower portion of a tubular drilling string; deflector means extending across the passage of said drive means; cutter means movable downwardly through the passage of said drive means and into engagement with said deflector means to be expanded thereby into driving relation to said tubular drive means and to a position extending laterally outwardly beyond the exterior of said drive means; said tubular drive means having a plurality of circumferentially spaced slots; said cutter means comprising a plurality of cutter members movable in tandem through the passage of said drive means and successively into engagement with said deflector means to be deflected thereby successively laterally into said slots and into coupling relation to said drive means; said cutter means being constructed and arranged to extend from a location closely adjacent to the axis of said tubular drive means to said extended position beyond said drive means to drill upon substantially the full cross-sectional area of the bottom of the bore hole upon being expanded into driving relation to said tubular drive means.

Claim 5

In an expansible and retractable drill bit for drilling a bore hole: tubular drive means attachable to the lower portion of a tubular drilling string; deflector means extending across the passage of said drive means; cutter means movable downwardly through the passage of said drive means and into engagement with said deflector means to be expanded thereby into driving relation to said tubular drive means and to a position extending laterally outwardly beyond the exterior of said drive means; said tubular drive means having a plurality of circumferentially spaced slots; said cutter means comprising a plurality of cutter members movable in tandem through the passage of said drive means and successively into engagement with said deflector means to be deflected thereby successively laterally into said slots and into coupling relation to said drive means; said cutter means being constructed and arranged to extend from a location closely adjacent to the axis of said tubular drive means to said extended position beyond said drive means to drill upon substantially the full cross-sectional area of the bottom of the bore hole upon being expanded into driving relation to said tubular drive means.

Claim 6

In a drill bit as defined in claim 3; and a plug bit secured to the inner portion of one of said cutter members for drilling the axial portion of the bottom of the bore hole.

Claim 7

In a drill bit as defined in claim 3; and holding means movable downwardly in said drive means passage behind said cutter means to retain said cutter means within said slots in their outwardly expanded position.

Claim 8

In a drill bit as defined in claim 3; and orienting means for aligning said cutter means with said slots to insure their outward deflection thereinto.

Claim 9

In a drill bit as defined in claim 3; orienting means for aligning said cutter means with said slots to insure their outward deflection thereinto; and holding means movable downwardly in said drive means passage behind said cutter means to retain said cutter means within said slots in their outwardly expanded position.

Claim 10

In a retractable and expansible drill bit: tubular drive means attachable to the lower portion of a tubular drilling string; deflector means rigidly fixed to said drive means and extending across the passage of said drive means; and cutter means movable downwardly through the passage of said drive means from a position completely above said deflector means and into engagement with said deflector means to be expanded thereby into driving relation to said tubular drive means and to a position extending laterally outwardly beyond the exterior of said drive means.

Claim 11

In a retractable and expansible drill bit: tubular drive means attachable to the lower portion of a tubular drilling string; deflector means rigidly fixed to said drive means and extending across the passage of said drive means; and cutter means movable downwardly through the passage of said drive means from a position completely above said deflector means and into engagement with said deflector means to be expanded thereby into driving relation to said tubular drive means and to a position extending laterally outwardly beyond the exterior of said drive means.

Claim 12

In a drill bit as defined in claim 8; said cutter means being constructed and arranged to extend from a location closely adjacent to the axis of said tubular drive means to said extended position beyond said drive means to drill upon substantially the full cross-sectional area of the bottom of the bore hole upon being expanded into driving relation to said tubular drive means.

Claim 13

In a drill bit as defined in claim 8; said tubular drive means having a plurality of circumferentially spaced slots; said cutter means comprising a plurality of cutter members movable in tandem through the passage of said drive means and successively into engagement with said deflector means to be deflected theReby successively laterally into said slots and into coupling relation to said drive means.

Claim 14

In a drill bit as defined in claim 8; said tubular drive means having a plurality of circumferentially spaced slots; said cutter means comprising a plurality of cutter members movable in tandem through the passage of said drive means and successively into engagement with said deflector means to be deflected thereby successively laterally into said slots and into coupling relation to said drive means; said cutter means being constructed and arranged to extend from a location closely adjacent to the axis of said tubular drive means to said extended position beyond said drive means to drill upon substantially the full cross-sectional area of the bottom of the bore hole upon being expanded into said slots and into coupling relation to said drive means.

Claim 15

In a drill bit as defined in claim 8; said tubular drive means having a plurality of circumferentially spaced slots; said cutter means comprising a plurality of cutter members movable in tandem through the passage of said drive means and successively into engagement with said deflector means to be deflected thereby successively laterally into said slots and into coupling relation to said drive means; said cutter members being constructed and arranged to extend from a location closely adjacent to the axis of said tubular drive means to said extended position beyond said drive means to drill upon substantially the full cross-sectional area of the bottom of the bore hole upon being expanded into said slots and into coupling relation to said drive means; and a plug bit secured to the inner portion of one of said cutter members for drilling the axial portion of the bottom of the bore hole.

Claim 16

In a retractable and expansible drill bit for drilling a bore hole: tubular drive means attachable to the lower portion of a tubular drilling string, said tubular drive means having a plurality of circumferentially spaced slots; deflector means rigidly fixed to said drive means and extending across the passage of said drive means, said deflector means being disposed adjacent said slots; carrier means adapted to be lowered and elevated through the drilling string on a wire line; cutter means carried by said carrier means and comprising a plurality of cutter members movable in tandem through the drilling string and drive means passage and successively into engagement with said deflector means to be expanded thereby successively laterally into said slots to extend beyond said drive means in coupling relation to said drive means; said carrier means being movable downwardly in said drive means passage behind said cutter means to retain said cutter members in coupling relation to said drive means.

Claim 17

In a retractable and expansible drill bit for drilling a bore hole: tubular drive means attachable to the lower portion of a tubular drilling string, said tubular drive means having a plurality of circumferentially spaced slots; deflector means rigidly fixed to said drive means and extending across the passage of said drive means, said deflector means being disposed adjacent said slots; carrier means adapted to be lowered and elevated through the drilling string on a wire line; cutter means carried by said carrier means and comprising a plurality of cutter members movable in tandem through the drilling string and drive means passage and successively into engagement with said deflector means to be expanded thereby successively laterally into said slots to extend beyond said drive means in coupling relation to said drive means; said carrier means being movable downwardly in said drive means passage behind said cutter means to retain said cutter members in coupling relation to said drive means.

Claim 18

In a drill bit as defined in claim 13; said cutter members having fluid passages therein for discharging drilling fluid toward the bottom of the bore hole; said carrier means having a central fluid passage communicating with said fluid passages when said carrier means is behind said cutter means.

Claim 19

In a drill bit as defined in claim 13; said cutter members having portions underlying and engaging said deflector means when said cutter members are coupled to said drive means.

Claim 20

In a drill bit as defined in claim 13; said cutter members having portions underlying and engaging said deflector means when said cutter members are coupled to said drive means; said cutter members having fluid passages therein for discharging drilling fluid toward the bottom of the bore hole; said carrier means having a central fluid passage communicating with said fluid passages when said carrier means is behind said cutter means.

Claim 21

In a drill bit as defined in claim 13; and orienting means within said drive means for aligning said cutter members with said slots to insure their outward expansion thereinto.

Claim 22

In a drill bit as defined in claim 13; said cutter members being constructed and arranged to extend from a location closely adjacent to the axis of said tUbular drive means to said extended position beyond said drive means to drill upon substantially the full cross-sectional area of the bottom of the bore hole upon being expanded into driving relation to said tubular drive means.

Claim 23

In a drill bit as defined in claim 13; said cutter members being constructed and arranged to extend from a location closely adjacent to the axis of said tubular drive means to said extended position beyond said drive means to drill upon substantially the full cross-sectional area of the bottom of the bore hole upon being expanded into driving relation to said tubular drive means; and a plug bit secured to the inner portion of one of said cutter members for drilling the axial portion of the bottom of the bore hole.

Claim 24

In a drill bit as defined in claim 13; said cutter members being constructed and arranged to extend from a location closely adjacent to the axis of said tubular drive means to said extended position beyond said drive means to drill upon substantially the full cross-sectional area of the bottom of the bore hole upon being expanded into driving relation to said tubular drive means; said cutter members having fluid passages therein for discharging drilling fluid toward the bottom of the bore hole; said carrier means having a fluid passage communicating with said fluid passages when said carrier means is behind said cutter means.

Claim 25

In a drill bit as defined in claim 13; said cutter members being constructed and arranged to extend from a location closely adjacent to the axis of said tubular drive means to said extended position beyond said drive means to drill upon substantially the full cross-sectional area of the bottom of the bore hole upon being expanded into driving relation to said tubular drive means; said cutter members having fluid passages therein for discharging drilling fluid toward the bottom of the bore hole; said carrier means having a fluid passage communicating with said fluid passages when said carrier means is behind said cutter means; said cutter members having portions underlying and engaging said deflector means when said cutter members are coupled to said drive means.