US4823267A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ratio control for continuously variable transmission for automotive vehicle
Assignee: Nissan Motor Co Ltd
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Filing: 1987-09-21
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Granted: 1989-04-18
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Expires: 2007-09-21
Abstract
Abstract A control system for a continuously variable transmission for an automotive vehicle, including a hydraulically operable driver pulley and follower pulley, a V-belt tensioned between the driver and follower pulleys, and means, including a shift actuator and a shift control valve, for hydraulically controlling a reduction ratio between the driver and follower pulleys by controlling a ratio of hydraulic fluid pressure applied to the driver pulley to hydraulic fluid pressure applied to the follower pulley. According to this control system, the continuously variable transmission is prohibited against effecting downshifting after predetermined conditions have been satisfied after application of the vehicle brake as detected by a brake sensor.
Inventors
- 👤 Haruyoshi Kumura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:41
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/66; F16H61/662; F16H61/66254; F16H61/66259; B; B60; B60W; B60W10/00; B60W10/10; B60W10/101; B60W10/107; B60W10/18; B60W30/00; B60W30/18; B60W2540/00; B60W2540/12; B60W2710/00; B60W2710/10; B60W2710/1005; F16H59/00; F16H59/50; F16H59/54; Y; Y10; Y10S; Y10S188/00; Y10S188/01
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
138 words
A control system for a continuously variable transmission for an automotive vehicle with a brake, including a hydraulically operable driver pulley and follower pulley, a V-belt tensioned between the driver and follower pulleys, and means, including a shift actuator and a shift control valve, for hydraulically controlling a reduction ratio between the driver and follower pulleys by controlling a ratio of hydraulic fluid pressure applied to the driver pulley to hydraulic fluid pressure applied to the follower pulley, the control system comprising: means for generating an output signal upon application of the brake of the vehicle; and means for controlling the shift actuator such that the continuously variable transmission is prohibited against effecting downshifting after predetermined conditions have been satisfied after application of the brake as indicated by said output signal generated by said output signal generating means.
Claim 2
Dependent Claim
138 words
A control system for a continuously variable transmission for an automotive vehicle with a brake, including a hydraulically operable driver pulley and follower pulley, a V-belt tensioned between the driver and follower pulleys, and means, including a shift actuator and a shift control valve, for hydraulically controlling a reduction ratio between the driver and follower pulleys by controlling a ratio of hydraulic fluid pressure applied to the driver pulley to hydraulic fluid pressure applied to the follower pulley, the control system comprising: means for generating an output signal upon application of the brake of the vehicle; and means for controlling the shift actuator such that the continuously variable transmission is prohibited against effecting downshifting after predetermined conditions have been satisfied after application of the brake as indicated by said output signal generated by said output signal generating means.
Claim 3
Dependent Claim
64 words
A control system as claimed in claim 1, wherein a position of a movable concical disc of one of the driver and follower pulleys is determined and the shift actuator is adjusted toward a position corresponding to the position of the movable conical disc determined for a predetermined length of time after said predetermined conditions have been satisfied after the application of the brake.
Claim 4
Dependent Claim
29 words
A control system as claimed in claim 2, wherein said predetermined length of time is determined as a function of at least a vehicle speed and a wheel deceleration.
Claim 5
Dependent Claim
45 words
A control system as claimed in claim 3, wherein the length of time is set longer than a time from the moment when the vehicle brake is applied to the moment when the vehicle comes to a halt during which the brake is kept applied.
Claim 6
Dependent Claim
60 words
A control system as claimed in claim 4, wherein said position of the movable conical disc of the pulley is determined by calculating an equation containing as variables a length of time from the application of the brake till the instance when said predetermined conditions are satisfied, a wheel deceleration and a transmission oil temperature of the continuously variable transmission.
Claim 7
Dependent Claim
37 words
A control system as claimed in claim 5, wherein, when the brake is kept applied upon elapse of the predetermined length of time, the continuously variable transmission is allowed to effect downshifting toward the largest reduction ratio.
Claim 8
Dependent Claim
26 words
A control system as claimed in claim 1, wherein said predetermined conditions are satisfied when a braked wheel stops rotating while the vehicle is still moving.
Claim 9
Dependent Claim
37 words
A control system as claimed in claim 7, wherein, when the brake is kept applied upon elapse of the predetermined length of time, the continuously variable transmission is allowed to effect downshifting toward the largest reduction ratio.
Claim 10
Dependent Claim
130 words
A control method for a continuously variable transmission for an automotive vehicle with a brake, including a hydraulically operable driver pulley and follower pulley, a V-belt tensioned between the driver and follower pulleys, and means, including a shift actuator and a shift control valve, for hydraulically controlling a reduction ratio between the driver and follower pulleys by controlling a ratio of hydraulic fluid pressure applied to the driver pulley to hydraulic fluid pressure applied to the follower pulley, the control method comprising the steps of: generating an output signal upon application of the brake of the vehicle; and controlling the shift actuator such that the continuously variable transmission is prohibited against effecting downshifting after predetermined conditions have been satisfied after application of the brake as indicated by said output signal.
Claim 11
Dependent Claim
130 words
A control method for a continuously variable transmission for an automotive vehicle with a brake, including a hydraulically operable driver pulley and follower pulley, a V-belt tensioned between the driver and follower pulleys, and means, including a shift actuator and a shift control valve, for hydraulically controlling a reduction ratio between the driver and follower pulleys by controlling a ratio of hydraulic fluid pressure applied to the driver pulley to hydraulic fluid pressure applied to the follower pulley, the control method comprising the steps of: generating an output signal upon application of the brake of the vehicle; and controlling the shift actuator such that the continuously variable transmission is prohibited against effecting downshifting after predetermined conditions have been satisfied after application of the brake as indicated by said output signal.
References Cited (Backward Citations)
US3893344A
Cited
JPS49103322A
Cited
US4458313A
Cited
JPS57161346A
Cited
US4543077A
Cited
US4559029A
Cited
JPS58170959A
Cited
JPS58170958A
Cited
EP0092227A1
Cited
US4597308A
Cited
US4590561A
Cited
US4589071A
Cited
EP0093413A1
Cited
US4579021A
Cited
US4533340A
Cited
EP0111891A2
Cited
US4603602A
Cited
US4660440A
Cited
US4653005A
Cited
US4670843A
Cited
US4637277A
Cited
US4665775A
Cited
US4669336A
Cited
DE3504763A1
Cited
US4702128A
Cited
US4736655A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-17 | 1992-10-17 | 1993-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-17 | 1996-10-17 | 1997-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-17 | 2000-10-17 | 2001-04-18 | $7700.00 | Window Closed / Lapsed |