US4545265A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic control system for continuously variable V-belt transmission
Assignee: Nissan Motor Co Ltd
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Filing: 1983-10-20
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Granted: 1985-10-08
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Expires: 2003-10-20
Abstract
Abstract A maximum reduction ratio maintaining valve is fluidly disposed between a drive pulley and a shift control valve which controls the supply of fluid to and discharge thereof from the drive pulley. The maximum reduction ratio maintaining valve drains the drive pulley to set a reduction ratio between the drive and driven pulleys at the largest reduction ratio to facilitate starting a vehicle.
Inventors
- 👤 Keiju Abo
- 👤 Sigeaki Yamamuro
- 👤 Yoshikazu Tanaka
- 👤 Haruyoshi Kumura
- 👤 Hiroyuki Hirano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:17
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/66; F16H61/662; F16H61/66254; F16H61/66263
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
141 words
In a hydraulic control system for a continuously variable V-belt transmission for a vehicle having an engine, the continuously variable V-belt transmission having a transmission mechanism including a driving pulley, a driven pulley, a V-belt running over both pulleys and a starting clutch which, when engaged, transmits an engine rotary power to the driving pulley, a shift control valve means for controlling the distribution of fluid pressure to both pulleys to vary a reduction ratio between the driving and driven pulleys; means for generating a driving pulley signal indicative of a revolution speed of the driving pulley; a maximum reduction ratio maintaining valve means responsive to said driving pulley signal for setting the reduction ratio between the driving and driven pulleys at the largest reduction ratio irrespective of the state of said shift control valve, to thereby facilitate starting the vehicle.
Claim 2
Dependent Claim
141 words
In a hydraulic control system for a continuously variable V-belt transmission for a vehicle having an engine, the continuously variable V-belt transmission having a transmission mechanism including a driving pulley, a driven pulley, a V-belt running over both pulleys and a starting clutch which, when engaged, transmits an engine rotary power to the driving pulley, a shift control valve means for controlling the distribution of fluid pressure to both pulleys to vary a reduction ratio between the driving and driven pulleys; means for generating a driving pulley signal indicative of a revolution speed of the driving pulley; a maximum reduction ratio maintaining valve means responsive to said driving pulley signal for setting the reduction ratio between the driving and driven pulleys at the largest reduction ratio irrespective of the state of said shift control valve, to thereby facilitate starting the vehicle.
Claim 3
Dependent Claim
115 words
A hydraulic control system as claimed in claim 1, wherein said shift control valve means controls the supply of fluid pressure to and discharge thereof from the driving pulley only, and wherein said maximum reduction ratio maintaining valve means includes a bore with an outlet port communicating with the driving pulley, an inlet port communicating with said shift control valve means to receive a regulated fluid pressure therefrom and a drain port, and also includes a spool movable responsive to said driving pulley signal within said bore between a first position wherein said outlet port communicates with said drain port only and a second position wherein said outlet port communicates with said inlet port only.
Claim 4
Dependent Claim
75 words
A hydraulic control system as claimed in claim 2, including means for generating an engine speed signal indicative of a revolution speed of the engine, wherein said maximum reduction ratio maintaining valve includes a spring biasing said spool toward said first position thereof, said spool being responsive also to said engine speed signal and being movable to said second position thereof when said driving pulley signal attains a predetermined relationship with said engine speed signal.
Claim 5
Dependent Claim
36 words
A hydraulic control system as claimed in claim 3, including a pressure regulator valve means for generating a line pressure, wherein said driven pulley communicates with said pressure regulator valve means to receive said line pressure.
Claim 6
Dependent Claim
55 words
A hydraulic control system as claimed in claim 1, wherein said maximum reduction ratio maintaining valve means is responsive to said driving pulley signal to cause the fluid pressure at the driving pulley to be set at a value which results in the largest reduction ratio irrespective of the state of said shift control valve.
References Cited (Backward Citations)
US3893344A
Cited
DE2703488A1
Cited
US4152947A
Cited
US4161894A
Cited
US4400164A
Cited
US4476746A
Cited
US4459878A
Cited
US4475416A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-10-07 | 1989-04-08 | 1989-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-07 | 1993-04-08 | 1993-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-07 | 1997-04-08 | 1997-10-08 | $7700.00 | Window Closed / Lapsed |