Patent US4862997A successfully refreshed from Google Patents.
Patent US4913005A successfully refreshed from Google Patents.
US4913005A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of controlling speed reduction ratio for a continuously variable speed transmission
Assignee: Honda Motor Co Ltd
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Filing: 1988-10-19
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Granted: 1990-04-03
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Expires: 2008-10-19
Abstract
Abstract The speed reduction ratio of a continuously variable speed transmission on a motor vehicle is controlled by continuously varying the speed reduction ratio in a range between a maximum speed reduction ratio and a minimum speed reduction ratio. A top limit speed reduction ratio corresponding to a speed of the motor vehicle and being higher than the minimium speed reduction ratio is set in a low vehicle speed range. The speed reduction ratio is controlled only between the maximum speed reduction ratio and the top limit speed reduction ratio in the low vehicle speed range.
Inventors
- 👤 Yoshikazu Ishikawa
- 👤 Kouji Yamaguchi
- 👤 Koji Sasajima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 00:22
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/38; F16H61/40; F16H61/42; F16H61/421; F16H61/425; F16H61/46; F16H61/462
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
99 words
A method of controlling a speed reduction ratio of a continuously variable speed transmission by continuously varying the speed reduction ratio in a range between a maximum speed reduction ratio and a minimum speed reduction ratio, said method comprising the steps of: setting a top limit speed reduction ratio corresponding to a speed of a vehicle and being higher than said minimum speed reduction ratio in a low vehicle speed range; and controlling the speed reduction ratio in a range between said maximum speed reduction ratio and said top limit speed reduction ratio in said low vehicle speed range.
Claim 2
Independent Claim
99 words
A method of controlling a speed reduction ratio of a continuously variable speed transmission by continuously varying the speed reduction ratio in a range between a maximum speed reduction ratio and a minimum speed reduction ratio, said method comprising the steps of: setting a top limit speed reduction ratio corresponding to a speed of a vehicle and being higher than said minimum speed reduction ratio in a low vehicle speed range; and controlling the speed reduction ratio in a range between said maximum speed reduction ratio and said top limit speed reduction ratio in said low vehicle speed range.
Claim 3
Dependent Claim
72 words
A method as defined in claim 1, wherein a low limit engine speed corresponding to said top limit speed reduction ratio in said low vehicle speed range is set and the speed reduction ratio is so controlled that an actual engine speed is higher than said low limit engine speed, thereby keeping the speed reduction ratio in a range between said maximum speed reduction ratio and said top limit speed reduction ratio.
Claim 4
Dependent Claim
67 words
A method as defined in claim 1, wherein said continuously variable speed transmission has a hydraulic pump coupled to said engine, a hydraulic motor coupled to an output shaft, and a closed hydraulic circuit hydraulically interconnecting said hydraulic pump and said hydraulic motor, and wherein said speed reduction ratio is controlled by variably controlling displacement of at least one of said hydraulic pump and said hydraulic motor.
Claim 5
Independent Claim
142 words
A method of controlling a speed reduction ratio of a continuously variable transmission by continuously varying the speed reduction ratio in a range between a maximum speed reduction ratio and a minimum speed reduction ratio, said method comprising the steps of, setting a top limit speed reduction ratio corresponding to a speed of a vehicle and being higher than said minimum speed reduction ratio in a low vehicle speed range, and if the speed of said vehicle is within said low vehicle speed range, then controlling the speed reduction ratio in a range between said maximum speed reduction ratio and said top limit speed reduction ratio, and if the speed of said vehicle is not within said low vehicle speed range, then controlling the speed reduction ratio in a range between said maximum speed reduction ratio and said minimum speed reduction ratio.
Claim 6
Independent Claim
142 words
A method of controlling a speed reduction ratio of a continuously variable transmission by continuously varying the speed reduction ratio in a range between a maximum speed reduction ratio and a minimum speed reduction ratio, said method comprising the steps of, setting a top limit speed reduction ratio corresponding to a speed of a vehicle and being higher than said minimum speed reduction ratio in a low vehicle speed range, and if the speed of said vehicle is within said low vehicle speed range, then controlling the speed reduction ratio in a range between said maximum speed reduction ratio and said top limit speed reduction ratio, and if the speed of said vehicle is not within said low vehicle speed range, then controlling the speed reduction ratio in a range between said maximum speed reduction ratio and said minimum speed reduction ratio.
Claim 7
Dependent Claim
73 words
A method of controlling a speed reduction ratio according to claim 4, further comprising the steps of, setting a low limit engine speed corresponding to said top limit speed reduction ratio in said low vehicle speed range, and if the speed of said vehicle is within said low vehicle speed range, then controlling the speed reduction ratio so that the speed of said engine is not less than said low limit engine speed.
Claim 8
Independent Claim
215 words
A method of controlling a speed reduction ratio of a continuously variable transmission of the type having a hydraulic pump and a hydraulic motor interconnected by a closed hydraulic circuit, said hydraulic pump being coupled to an engine of a vehicle for driving said pump, said hydraulic motor being coupled to at least one wheel of said vehicle for driving said vehicle, at least one of said hydraulic pump and said hydraulic motor being of the variable displacement type, wherein said continuously variable transmission is controlled by continuously varying the speed reduction ratio in a range between a maximum speed reduction ratio and a minimum speed reduction ratio, said method comprising the steps of, setting a top limit speed reduction ratio corresponding to a speed of a vehicle and being higher than said minimum speed reduction ratio in a low vehicle speed range, and if the speed of said vehicle is within said low vehicle speed range, then controlling the speed reduction ratio in a range between said maximum speed reduction ratio and said top limit speed reduction ratio, and if the speed of said vehicle is not within said low vehicle speed range, then controlling the speed reduction ratio in a range between said maximum speed reduction ratio and said minimum speed reduction ratio.
Claim 9
Independent Claim
215 words
A method of controlling a speed reduction ratio of a continuously variable transmission of the type having a hydraulic pump and a hydraulic motor interconnected by a closed hydraulic circuit, said hydraulic pump being coupled to an engine of a vehicle for driving said pump, said hydraulic motor being coupled to at least one wheel of said vehicle for driving said vehicle, at least one of said hydraulic pump and said hydraulic motor being of the variable displacement type, wherein said continuously variable transmission is controlled by continuously varying the speed reduction ratio in a range between a maximum speed reduction ratio and a minimum speed reduction ratio, said method comprising the steps of, setting a top limit speed reduction ratio corresponding to a speed of a vehicle and being higher than said minimum speed reduction ratio in a low vehicle speed range, and if the speed of said vehicle is within said low vehicle speed range, then controlling the speed reduction ratio in a range between said maximum speed reduction ratio and said top limit speed reduction ratio, and if the speed of said vehicle is not within said low vehicle speed range, then controlling the speed reduction ratio in a range between said maximum speed reduction ratio and said minimum speed reduction ratio.
Claim 10
Independent Claim
148 words
A method of controlling a speed reduction ratio in a continuously variable transmission by continuously varying the speed reduction ratio in a range between a maximum speed reduction ratio and a minimum speed reduction ratio, said method comprising the steps of, reading the speed reduction ratio of said transmission, reading a speed of a vehicle in which said transmission is carried, setting a top limit speed reduction ratio corresponding to a speed of said vehicle and being higher than said minimum speed reduction ratio in a low vehicle speed range, determining whether said speed reduction ratio is less than said top limit speed reduction ratio, and if said speed reduction ratio is less than said top limit speed reduction ratio and the vehicle speed is within said low vehicle speed range, then controlling the speed reduction ratio so as to coincide with said top limit speed reduction ratio.
Claim 11
Independent Claim
148 words
A method of controlling a speed reduction ratio in a continuously variable transmission by continuously varying the speed reduction ratio in a range between a maximum speed reduction ratio and a minimum speed reduction ratio, said method comprising the steps of, reading the speed reduction ratio of said transmission, reading a speed of a vehicle in which said transmission is carried, setting a top limit speed reduction ratio corresponding to a speed of said vehicle and being higher than said minimum speed reduction ratio in a low vehicle speed range, determining whether said speed reduction ratio is less than said top limit speed reduction ratio, and if said speed reduction ratio is less than said top limit speed reduction ratio and the vehicle speed is within said low vehicle speed range, then controlling the speed reduction ratio so as to coincide with said top limit speed reduction ratio.
Claim 12
Independent Claim
148 words
A method of controlling a speed reduction ratio in a continuously variable transmission by continuously varying the speed reduction ratio in a range between a maximum speed reduction ratio and a minimum speed reduction ratio, said method comprising the steps of, reading an engine speed of an engine in a vehicle in which said transmission is carried, reading a speed of said vehicle, setting a low limit engine speed corresponding to a top limit speed reduction ratio that is higher than said minimum speed reduction ratio in a low vehicle speed range, determining whether said engine speed is less than said low limit engine speed, and if said engine speed is lower than said low limit engine speed and the vehicle speed is within said low vehicle speed range, then controlling the speed reduction ratio to cause the engine speed to coincide with said low limit engine speed.
Claim 13
Independent Claim
148 words
A method of controlling a speed reduction ratio in a continuously variable transmission by continuously varying the speed reduction ratio in a range between a maximum speed reduction ratio and a minimum speed reduction ratio, said method comprising the steps of, reading an engine speed of an engine in a vehicle in which said transmission is carried, reading a speed of said vehicle, setting a low limit engine speed corresponding to a top limit speed reduction ratio that is higher than said minimum speed reduction ratio in a low vehicle speed range, determining whether said engine speed is less than said low limit engine speed, and if said engine speed is lower than said low limit engine speed and the vehicle speed is within said low vehicle speed range, then controlling the speed reduction ratio to cause the engine speed to coincide with said low limit engine 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) | 1993-04-02 | 1993-10-02 | 1994-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-02 | 1997-10-02 | 1998-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-02 | 2001-10-02 | 2002-04-03 | $7700.00 | Window Closed / Lapsed |