Patent US3312293A successfully refreshed from Google Patents.
US3312293A
Expired / Lapsed
US
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Spring operated demolition device
Assignee: ROOFING MACHINERY Mfg CO
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Filing: 1964-07-10
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Granted: 1967-04-04
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Expires: 1984-07-10
Abstract
No abstract record available.
Inventors
- 👤 Earl F Cutler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 04:09
CPC Classifications
E; E01; E01C; E01C23/00; E01C23/06; E01C23/12; E01C23/122; E01C23/124
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
124 words
IN A POWER HAMMER OF THE TYPE HAVING A HAMMER SHAFT INCLUDING A HAMMER HEAD WHICH IS ADAPTED TO STRIKE AN ANVIL CARRIED ON ONE END OF A TOOL-CARRYING ANVIL SHAFT IN ORDER TO DELIVER A BLOW, INCLUDING SPRING MEANS FOR FORCING SAID HAMMER SHAFT DOWNWARDLY TOWARD SAID ANVIL AND MEANS FOR RETRACTING SAID HAMMER SHAFT AGAINST THE FORCE OF SAID SPRING MEANS AFTER DELIVERY OF EACH BLOW, THE IMPROVEMENT COMPRISING, A HOUSING, AND A PLURALITY OF HELICAL COMPRESSION SPRINGS DISPOSED WITHIN SAID HOUSING AND CIRCUMFERENTIALLY SPACED THEREIN, EACH OF SAID SPRINGS BEING PARALLEL TO SAID HAMMER SHAFT AND HAVING ONE END ABUTTING AGAINST A FIXED PORTION OF SAID HOUSING WITH ITS OTHER END ACTING TO URGE SAID HAMMER SHAFT DOWNWARDLY TOWARD SAID ANVIL.
References Cited (Backward Citations)
US1176041A
Cited
US1267174A
Cited
US1356556A
Cited
US1891221A
Cited
CH206253A
Cited
US2796856A
Cited
US3039758A
Cited
US3179185A
Cited
US3149682A
Cited
US3244241A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-04-03 | 1970-10-03 | 1971-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-04-03 | 1974-10-03 | 1975-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-04-03 | 1978-10-03 | 1979-04-04 | $7700.00 | Window Closed / Lapsed |