Patent US3265220A successfully refreshed from Google Patents.
US3265220A
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Safety control for extensible boom cranes
Assignee: DROTT Manufacturing CORP
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Filing: 1965-10-19
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Granted: 1966-08-09
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Expires: 1985-10-19
Abstract
No abstract record available.
Inventors
- 👤 Sidney G Knight
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 03:08
CPC Classifications
B; B66; B66C; B66C23/00; B66C23/88; B66C23/90; B66C23/905
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
108 words
SAFETY CONTROL MEANS FOR CRANES IN COMBINATION WITH A CRANE HAVING AN EXTENSIBLE BOOM, POWER MEANS TO EXTEND AND RETRACT THE BOOM, A CABLE RUNNING OVER A BLOCK AT THE END OF THE BOOM, A SECOND BLOCK SUPPORTED BY THE CABLE, POWER OPERATED DRUM MEANS TO EXTEND AND RETRACT THE CABLE THEREBY TO LOWER AND RAISE THE SECOND BLOCK, THE SAFETY CONTROL MEANS COMPRISING A CONTROL DEVICE OPERATED BY THE BLOCK WHEN THE SECOND BLOCK MOVES INTO CLOSE PROXIMITY TO THE FIRST BLOCK, AND MEANS OPERATED BY THE CONTROL DEVICE WHEN IT IS OPERATED TO PREVENT OPERATION OF THE POWER MEANS IN A DIRECTION TO EXTEND THE BOOM.
Claim 2
Dependent Claim
108 words
SAFETY CONTROL MEANS FOR CRANES IN COMBINATION WITH A CRANE HAVING AN EXTENSIBLE BOOM, POWER MEANS TO EXTEND AND RETRACT THE BOOM, A CABLE RUNNING OVER A BLOCK AT THE END OF THE BOOM, A SECOND BLOCK SUPPORTED BY THE CABLE, POWER OPERATED DRUM MEANS TO EXTEND AND RETRACT THE CABLE THEREBY TO LOWER AND RAISE THE SECOND BLOCK, THE SAFETY CONTROL MEANS COMPRISING A CONTROL DEVICE OPERATED BY THE BLOCK WHEN THE SECOND BLOCK MOVES INTO CLOSE PROXIMITY TO THE FIRST BLOCK, AND MEANS OPERATED BY THE CONTROL DEVICE WHEN IT IS OPERATED TO PREVENT OPERATION OF THE POWER MEANS IN A DIRECTION TO EXTEND THE BOOM.
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) | 1969-08-08 | 1970-02-07 | 1970-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-08-08 | 1974-02-07 | 1974-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-08-08 | 1978-02-07 | 1978-08-09 | $7700.00 | Window Closed / Lapsed |