US5353662A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transmission shuttle shift deceleration method
Assignee: Deere and Co
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Filing: 1993-01-29
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Granted: 1994-10-11
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Expires: 2013-01-29
Abstract
Abstract A powershift transmission includes a plurality of clutches, including a final or directional set of clutches. The clutches are controlled by electro-hydraulic direct acting valves and two electro-hydraulic proportional or pressure modulating valves. The pressure modulating valves modulate the pressure supplied to the direct acting valves associated with the three directional clutches. Vehicle deceleration during a shuttle shift is achieved by releasing (unpressurizing) all clutches, then gradually pressurizing only two clutches in the final or directional set.
Inventors
- 👤 Kevin L. Vaughters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 16:17
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/02; F16H61/0202; F16H61/0204; F16H61/0246; F16H59/00; F16H59/02; F16H59/08; F16H2059/082; F16H2059/088; F16H61/0251; F16H2061/0258; F16H61/0059; F16H61/68; F16H61/684; F16H61/70; Y; Y10; Y10T; Y10T74/00; Y10T74/19; Y10T74/19219; Y10T74/19251; Y10T74/19256; Y10T74/1926
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
143 words
A method of decelerating an output shaft of a vehicle powershift transmission during a shuttle shift whereby rotation of the output shaft is reversed from a first direction to a second direction, the transmission having a plurality of hydraulic pressure operated clutch elements for shifting the transmission, including a set of directional clutches, the method comprising the following steps: disengaging all the clutch elements, including all the directional clutches; applying pressurized fluid to only to both a first directional clutch and to a second directional clutch to lock up the transmission; when the output shaft speed is less than a threshold value, applying pressurized fluid to at least one selected clutch other than a directional clutch to engage a desired gear and to cause the output shaft to rotate in the second direction; and releasing pressure from at least the first directional clutch.
Claim 2
Independent Claim
143 words
A method of decelerating an output shaft of a vehicle powershift transmission during a shuttle shift whereby rotation of the output shaft is reversed from a first direction to a second direction, the transmission having a plurality of hydraulic pressure operated clutch elements for shifting the transmission, including a set of directional clutches, the method comprising the following steps: disengaging all the clutch elements, including all the directional clutches; applying pressurized fluid to only to both a first directional clutch and to a second directional clutch to lock up the transmission; when the output shaft speed is less than a threshold value, applying pressurized fluid to at least one selected clutch other than a directional clutch to engage a desired gear and to cause the output shaft to rotate in the second direction; and releasing pressure from at least the first directional clutch.
Claim 3
Dependent Claim
26 words
The method of claim 1, wherein: the pressure applied to the first and second directional clutches is gradually increased to gradually decelerate the output shaft in.
Claim 4
Dependent Claim
26 words
The method of claim 1, further comprising: gradually increasing the pressure applied to a directional clutch to gradually accelerate the output shaft in the second direction.
References Cited (Backward Citations)
US4768636A
Cited
US4843902A
Cited
US4864881A
Cited
US4914983A
Cited
US4989470A
Cited
US5012690A
Cited
US5036718A
Cited
US5082097A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-10-10 | 1998-04-11 | 1998-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-10 | 2002-04-11 | 2002-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-10 | 2006-04-11 | 2006-10-11 | $7700.00 | Window Closed / Lapsed |