US3880247A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Replaceable drill bit for rotary drilling of bore holes
Assignee: Individual
•
Filing: 1972-08-23
•
Granted: 1975-04-29
•
Expires: 1992-08-23
Abstract
Abstract A rotary drill bit which is releasably attachable to a string of drill pipe and is insertable and retrievable through the drill pipe thus eliminating the costly and time consuming operation of raising and lowering the string of drill pipe when it becomes necessary to change drill bits.
Inventors
- 👤 Thomas J Harding
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:08
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/64; E21B10/66
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
97 words
In a bore hole drilling system including a rotatable string of drill pipe and a retrievable drill bit the improvement comprising means for attaching the bit to the lower end of the drill pipe, said attaching means including: a hollow cylindrical body having a radially expanding groove means in the interior wall thereof; an extensible latching means affixed to said bit slidably engaging the groove means in the interior wall of said body; and a wedge slidably movable in said bit for contact with said extensible latching means to effect the movement of said extensible latching means.
Claim 2
Dependent Claim
97 words
In a bore hole drilling system including a rotatable string of drill pipe and a retrievable drill bit the improvement comprising means for attaching the bit to the lower end of the drill pipe, said attaching means including: a hollow cylindrical body having a radially expanding groove means in the interior wall thereof; an extensible latching means affixed to said bit slidably engaging the groove means in the interior wall of said body; and a wedge slidably movable in said bit for contact with said extensible latching means to effect the movement of said extensible latching means.
Claim 3
Dependent Claim
74 words
The system according to claim 1 wherein said extensible latching means includes a movable pin radially disposed from the longitudinal axis of said bit and slidably movable in said bit having one end adjacent the longitudinal axis of said bit for contact with said wedge and the other end adjacent an exterior side wall of said bit wherein said pin is extensible beyond said exterior side wall for slidable engagement with said groove means.
Claim 4
Dependent Claim
26 words
The system according to claim 1 wherein said radially expanding groove means includes at least two radially expanding grooves in the interior wall of said body.
Claim 5
Dependent Claim
76 words
The system according to claim 3 wherein said extensible latching means includes a least two pins radially disposed from the longitudinal axis of said bit and slidably movable in said bit, each having one end adjacent the longitudinal axis of said bit for contact with said wedge and the other end adjacent an exterior side wall of said bit wherein said pins are extensible beyond said exterior side wall for slidable engagement with said groove means.
Claim 6
Dependent Claim
18 words
The system according to claim 2 wherein said extensible latching means includes means to retract said movable pin.
Claim 7
Dependent Claim
14 words
The system according to claim 5 wherein said means to retract includes spring means.
Claim 8
Dependent Claim
14 words
The system according to claim 5 wherein said means to retract includes magnetic means.
Claim 9
Dependent Claim
19 words
The system according to claim 1 wherein said hollow cylindrical body is the lower end of said drill pipe.
Claim 10
Dependent Claim
39 words
The system according to claim 1 including a circumferential groove means in the interior wall of said body and a means pivotally affixed to said bit for engaging said circumferential groove means in the interior wall of said body.
Claim 11
Dependent Claim
20 words
The system according to claim 9 wherein said means for engaging includes a key section pivotally affixed to said bit.
Claim 12
Dependent Claim
22 words
The system according to claim 9 wherein said means for engaging includes at least two key sections pivotally affixed to said bit.
Claim 13
Dependent Claim
25 words
The system according to claim 9 wherein said wedge is slidably movable in said bit to effect the pivotal movement of said means for engaging.
Claim 14
Dependent Claim
19 words
The system according to claim 9 wherein said hollow cylindrical body is the lower end of said drill pipe.
Claim 15
Dependent Claim
23 words
The system according to claim 12 wherein the cutters of said bit are attached to said means for engaging and to said wedge.
Claim 16
Dependent Claim
24 words
The system according to claim 14 wherein said cutters include rotatable cutters having cutting surfaces extending substantially across the diameter of the bore hole.
References Cited (Backward Citations)
US862381A
Cited
US1142460A
Cited
US1395081A
Cited
US2876994A
Cited
US2978047A
Cited
US3097706A
Cited
US3656564A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-28 | 1978-10-28 | 1979-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-28 | 1982-10-28 | 1983-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-28 | 1986-10-28 | 1987-04-29 | $7700.00 | Window Closed / Lapsed |