Patent US3307875A successfully refreshed from Google Patents.
US3307875A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Primary and secondary cutter bit arrangement and method of operation
Assignee: Joy Manufacturing Co
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Filing: 1964-05-22
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Granted: 1967-03-07
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Expires: 1984-05-22
Abstract
No abstract record available.
Inventors
- 👤 Glenn S Mcdowell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:24
CPC Classifications
E; E21; E21C; E21C25/00; E21C25/22; E21C25/28; E21C25/34; E21C35/00; E21C35/18
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
83 words
A MINING METHOD IN WHICH A PLURALITY OF ORBITALLY MOVING MEMBERS HAVE CUTTING EDGES SEQUENTIALLY ENGAGING A MINERAL IN SITU COMPRISING THE STEP OF: CUTTING SPACED PORTIONS OF SUCH MINERAL TO FORM A PLURALITY OF ELONGATED LATERALLY SPACED KERFS IN SAID MINERAL WITH ELONGATED FREE EDGED CORES OF UNMINED MINERAL THEREBETWEEN; SUBSEQUENTLY CUTTING A SECOND PORTION OF MINERALS TO DEEPEN ADJOINING KERFS AND INCREASE THE HEIGHT OF THE CORE THEREBETWEEN; THEREAFTER REMOVING A MAJOR PORTION OF SAID CORE FROM THE FREE EDGE THEREOF.
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) | 1970-03-06 | 1970-09-05 | 1971-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-03-06 | 1974-09-05 | 1975-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-03-06 | 1978-09-05 | 1979-03-07 | $7700.00 | Window Closed / Lapsed |