Patent US4579024A successfully refreshed from Google Patents.
US4579024A
Expired / Lapsed
US
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Power tongs and control system
Assignee: Bilco Tools Inc
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Filing: 1984-07-10
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Granted: 1986-04-01
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Expires: 2004-07-10
Abstract
Abstract A control system for power tongs comprises two tongs torque limiters, one of which limits tongs torque to a very low (hand-tight) level; the other limits torque at full makeup to, for example, 2000 ft. lb. The hand-tight torque limiter is manually or automatically disabled after the hand-tight level is reached. The system enables the operator to verify that the threads are properly engaged before applying full torque to the connection. The tongs have a very high reduction ratio, so that torque rises very slowly and can be more accurately controlled.
Inventors
- 👤 William E. Coyle, Sr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:14
CPC Classifications
E; E21; E21B; E21B19/00; E21B19/16; E21B19/165; E21B19/166
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
93 words
A control system for a power tongs comprising a snub line for restraining the tongs, a first snub line tension transducer for generating signals proportional to tongs torque in the hand-tight range, a second snub line tension transducer for generating signals proportional to tongs torque in the full makeup torque range, first means responsive to said first transducer for halting tongs operation at a preset hand-tight torque level, second means responsive to said second transducer for halting tongs operation at a preset full makeup torque level, and means for disabling said first means.
Claim 2
Dependent Claim
93 words
A control system for a power tongs comprising a snub line for restraining the tongs, a first snub line tension transducer for generating signals proportional to tongs torque in the hand-tight range, a second snub line tension transducer for generating signals proportional to tongs torque in the full makeup torque range, first means responsive to said first transducer for halting tongs operation at a preset hand-tight torque level, second means responsive to said second transducer for halting tongs operation at a preset full makeup torque level, and means for disabling said first means.
Claim 3
Dependent Claim
33 words
The system described in claim 1 wherein said tongs have high and low speeds and a gear selector for choosing between said speeds, and said disabling means is controlled by said gear selector.
Claim 4
Dependent Claim
30 words
The system described in claim 2 wherein said disabling means is actuated to disable said first means only when the tongs are operated in the lower of said two speeds.
Claim 5
Dependent Claim
19 words
The system described in claim 3 wherein the ratio between said high and low speeds is at least 4:1.
Claim 6
Dependent Claim
31 words
The system described in claim 4 wherein the overall gear ratio between the tongs motor and the tongs jaws is about 250:1 in low speed and about 60:1 in high speed.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-03-31 | 1989-09-30 | 1990-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-31 | 1993-09-30 | 1994-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-31 | 1997-09-30 | 1998-04-01 | $7700.00 | Window Closed / Lapsed |