US3831465A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control system for automatic transmission
Assignee: Aisin Corp
•
Filing: 1972-10-02
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Granted: 1974-08-27
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Expires: 1992-10-02
Abstract
Abstract In an automotive power transmission having at least two friction engaging devices to establish different forward speed ratio power trains therethrough, a hydraulic control system therefor is provided with a cooperating pair of modulator valves. Fluid pressures selectively fed to and from the friction engaging devices under the control of various shift valve devices are modulated by the modulator valves to minimize the jerks that may be produced during the transition.
Inventors
- 👤 N Murakami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 00:21
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/04; F16H61/06; F16H61/065; Y; Y10; Y10S; Y10S74/00; Y10S74/01
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
252 words
In an automatic transmission having a drive shaft, a driven shaft, and at least two selectively engagable frictional engaging means provided between said shafts to establish different driving ratios between the shafts, a control system comprising: a source of fluid pressure; shift valve means provided between said source and said frictional engaging means and controlling selectively fluid pressure communication therebetween in a manner to engage one of said frictional engaging means and to disengage the other frictional engaging means; modulator valve means disposed between said shift valve means and said frictional engaging means and including first means responsive to reduction of engaging pressure in said other engaging means to be disengaged and second means responsive to an increase of the engaging pressure in said one engaging means to be engaged; and means associating said first and second means such that when said first means is in a condition subjected to a value of the engaging pressure at which slip of said other engaging means is about to occur, said second means is in a condition subjected to a value of the engaging pressure at which the engagement of said one engaging means is about to occur and that said first and second means thereafter operate to control the engaging pressures, in response to the respective engaging pressures of both said engaging means, so as to cause said one engaging means to be engaged and said other engaging means to be disengaged with the engaging pressures varying in inverse proportion to each other.
Claim 2
Dependent Claim
252 words
In an automatic transmission having a drive shaft, a driven shaft, and at least two selectively engagable frictional engaging means provided between said shafts to establish different driving ratios between the shafts, a control system comprising: a source of fluid pressure; shift valve means provided between said source and said frictional engaging means and controlling selectively fluid pressure communication therebetween in a manner to engage one of said frictional engaging means and to disengage the other frictional engaging means; modulator valve means disposed between said shift valve means and said frictional engaging means and including first means responsive to reduction of engaging pressure in said other engaging means to be disengaged and second means responsive to an increase of the engaging pressure in said one engaging means to be engaged; and means associating said first and second means such that when said first means is in a condition subjected to a value of the engaging pressure at which slip of said other engaging means is about to occur, said second means is in a condition subjected to a value of the engaging pressure at which the engagement of said one engaging means is about to occur and that said first and second means thereafter operate to control the engaging pressures, in response to the respective engaging pressures of both said engaging means, so as to cause said one engaging means to be engaged and said other engaging means to be disengaged with the engaging pressures varying in inverse proportion to each other.
Claim 3
Dependent Claim
52 words
The automatic transmission as claimed in claim 1, in which said second means includes means displaceable in response to the engaging pressure of said one engaging means, and said first means includes means to control the engaging pressure of said other engaging means in response to the displacement of said displaceable means.
Claim 4
Dependent Claim
38 words
The automatic transmission as claimed in claim 2, in which said displaceable means includes cam means, and said first means includes a piston movable with said cam means to control the engaging pressure of said other engaging means.
Claim 5
Dependent Claim
102 words
The automatic transmission as claimed in claim 1, in which said second means includes pressure modulating means movable in one direction, in response to the engaging pressure of said one engaging means, thereby to keep the engaging pressure at a level slightly below the level at which said one engaging means begins torque transmission and moving means acted upon by the engaging pressure of said one engaging means through orifice means thereby to move said modulating means in the other direction, and said first means includes means responsive to the engaging pressure of said other engaging means to counteract said moving means.
Claim 6
Dependent Claim
97 words
The automatic transmission as claimed in claim 4, in which said modulator valve means modulates the fluid pressures for engagement and disengagement of said engaging means in such an interrelated manner that when, for a shift from one forward speed ratio to another, the fluid pressure which has been causing engagement of said one engaging means has decreased to a value at which no substantial torque transmission takes place through said one engaging means, and the fluid pressure supplied for engagement of said other engaging means will attain a value at which torque transmission takes place therethrough.
Claim 7
Dependent Claim
57 words
The automatic transmission as claimed in claim 4, in which said pressure modulating means of said second means includes a first piston operating to bleed the engaging pressure of said one engaging means, said moving means to move said modulating means in said other direction includes a second piston, and said first means includes a third piston.
Claim 8
Dependent Claim
31 words
The automatic transmission as claimed in claim 6, further including first spring means disposed between said first and second pistons, and second spring means disposed between said second and third pistons.
Claim 9
Dependent Claim
52 words
The automatic transmission as claimed in claim 4, in which said modulator valve means modulates the fluid pressure for engagement and disengagement of said engaging means in an interrelated manner in response to the variable amount of torque transmitted by the transmission during a shift from one forward speed ratio to another.
Claim 10
Dependent Claim
33 words
The automatic transmission as claimed in claim 8, in which said torque is in inverse proportion to the speed of a vehicle and in direct proportion to the opening of a throttle valve.
Claim 11
Dependent Claim
53 words
The automatic transmission as claimed in claim 9, further including control means generating an output pressure inversely proportional to the vehicle speed and porportional to the opening of the throttle valve, said output pressure being applied to said modulator valve means so as to counteract said first means of the modulator valve means.
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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) | 1977-08-26 | 1978-02-25 | 1978-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-26 | 1982-02-25 | 1982-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-26 | 1986-02-25 | 1986-08-27 | $7700.00 | Window Closed / Lapsed |