US3854766A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Log grapple device
Assignee: Individual
•
Filing: 1973-04-13
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Granted: 1974-12-17
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Expires: 1993-04-13
Abstract
Abstract A system for automatically holding and/or restoring pressure to log grapple tongs despite shifting of the logs in the tongs.
Inventors
- 👤 B Jordan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 01:05
CPC Classifications
F; F15; F15B; F15B1/00; F15B1/02; F15B1/027; B; B66; B66C; B66C3/00; B66C3/14; B66C3/16; F15B1/033
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
166 words
A log grapple mounted on a vehicle, said log grapple comprising two tongs that are mounted on said vehicle so as to be movable toward and away from each other, at least one hydraulic cylinder for moving said tongs toward and away from each other, a hydraulic circuit including a hydraulic pump for supplying hydraulic power to said at least one hydraulic cylinder, said hydraulic circuit including: a. unloader valve means for unloading the hydraulic pump after the tongs have initially obtained a firm grip on a group of logs, b. means for thereafter sensing any pressure drop in said at least one cylinder that may be due to a slippage or shifting of the logs within the grasp of the grapple, c. means for automatically and substantially instantaneously restoring the pressure in said at least one hydraulic cylinder to the pressure which existed in said at least one hydraulic cylinder at the time that it attained its initial firm grip on said group of logs.
Claim 2
Dependent Claim
166 words
A log grapple mounted on a vehicle, said log grapple comprising two tongs that are mounted on said vehicle so as to be movable toward and away from each other, at least one hydraulic cylinder for moving said tongs toward and away from each other, a hydraulic circuit including a hydraulic pump for supplying hydraulic power to said at least one hydraulic cylinder, said hydraulic circuit including: a. unloader valve means for unloading the hydraulic pump after the tongs have initially obtained a firm grip on a group of logs, b. means for thereafter sensing any pressure drop in said at least one cylinder that may be due to a slippage or shifting of the logs within the grasp of the grapple, c. means for automatically and substantially instantaneously restoring the pressure in said at least one hydraulic cylinder to the pressure which existed in said at least one hydraulic cylinder at the time that it attained its initial firm grip on said group of logs.
Claim 3
Dependent Claim
24 words
A log grapple device according to claim 1 wherein said pressure restoring means include A closer center valve in combination with an unloader valve.
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) | 1977-12-16 | 1978-06-17 | 1978-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-16 | 1982-06-17 | 1982-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-16 | 1986-06-17 | 1986-12-17 | $7700.00 | Window Closed / Lapsed |