Patent US3306377A successfully refreshed from Google Patents.
US3306377A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Collapsible drill bit
Assignee: Individual
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Filing: 1963-12-23
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Granted: 1967-02-28
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Expires: 1983-12-23
Abstract
No abstract record available.
Inventors
- 👤 Howard L Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:32
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/64; E21B10/66
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
108 words
A TUBULAR BIT-ENGAGING SEGMENT ADAPTED TO FORM THE DISTAL TERMINUS OF A ROTARY DRILL STEM, WHICH SEGMENT IS ADAPTED FOR THRUST ENGAGEMENT IN ROTARY DRIVING RELATION WITH A COLLAPSIBLE DRILL BIT OF THE CHARACTER DESCRIBED, SAID TUBULAR SEGMENT BEING FORMED WITH A CIRCULAR SERIES OF DOWNWARD EXTENDING, BOTTOM EDGE PROJECTIONS CONSISTING OF BIT-ENGAGING TEETH ALTERNATING WITH LONGER, DOWNWARDLY CONVERGING INSERTS, THE INSERTS CORRESPONDING IN NUMBER TO THE NUMBER OF RADIALLY TILTABLE, UPSTANDING SEGMENTS FORMING A SEGMENT-ENGAGING CIRCLE OF A COLLAPSIBLE BIT TO WHICH SAID TUBULAR SEGMENT MAY BE COUPLED, EACH INSERT BEING FRICTIONALLY LONGITUDINALLY RECEIVABLE BETWEEN AN ADJACENT PAIR OF SUCH SEGMENTS WHEN OUT-TILTED FOR LATERAL EDGE EN-
Claim 2
Dependent Claim
108 words
A TUBULAR BIT-ENGAGING SEGMENT ADAPTED TO FORM THE DISTAL TERMINUS OF A ROTARY DRILL STEM, WHICH SEGMENT IS ADAPTED FOR THRUST ENGAGEMENT IN ROTARY DRIVING RELATION WITH A COLLAPSIBLE DRILL BIT OF THE CHARACTER DESCRIBED, SAID TUBULAR SEGMENT BEING FORMED WITH A CIRCULAR SERIES OF DOWNWARD EXTENDING, BOTTOM EDGE PROJECTIONS CONSISTING OF BIT-ENGAGING TEETH ALTERNATING WITH LONGER, DOWNWARDLY CONVERGING INSERTS, THE INSERTS CORRESPONDING IN NUMBER TO THE NUMBER OF RADIALLY TILTABLE, UPSTANDING SEGMENTS FORMING A SEGMENT-ENGAGING CIRCLE OF A COLLAPSIBLE BIT TO WHICH SAID TUBULAR SEGMENT MAY BE COUPLED, EACH INSERT BEING FRICTIONALLY LONGITUDINALLY RECEIVABLE BETWEEN AN ADJACENT PAIR OF SUCH SEGMENTS WHEN OUT-TILTED FOR LATERAL EDGE EN-
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-02-27 | 1970-08-29 | 1971-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-02-27 | 1974-08-29 | 1975-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-02-27 | 1978-08-29 | 1979-02-28 | $7700.00 | Window Closed / Lapsed |