US3744348A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Planetary transmission mechanism and hydraulic control
Assignee: Aisin AW Co Ltd
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Filing: 1971-06-01
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Granted: 1973-07-10
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Expires: 1991-06-01
Abstract
Abstract An automatic transmission mechanism including a planetary gear train and a hydraulic control mechanism adapted to control engagement of friction engaging devices for establishing various drive ratios through the gear train. The planetary transmission including first and second clutch mechanisms, a one-way brake mechanism to establish low gear ratio and a one-way brake mechanism to establish second gear ratio, the engagement of both said clutch mechanisms providing a 1:1 direct drive ratio. A friction brake mechanism is provided in parallel with each of said one-way brake mechanisms to provide first and second two-way drive ratios through the transmission mechanism. One of the clutch mechanisms includes a double hydraulic servomotor arrangement whereby a minimum engaging force can be utilized for one of the clutches, for direct drive to provide for a smooth shift to direct drive and whereby when reverse ratio is established utilizing the same clutch mechanism both hydraulic servomotors for the clutch can be actuated to provide the high engagement force required for reverse drive. A double hydraulic servomotor also is provided for the friction brake mechanism for low drive ratio whereby a single one of said servomotors can be utilized for low drive ratio and both servomotors can be utilized to engage the same brake mechanism for reverse ratio when a higher engaging force is required. The hydraulic control mechanism including engine torque and vehicle speed responsive accumulator devices for each of the clutch mechanisms and for a second speed brake mechanism. Sequencing valves being included in the control mechanism to insure that when reverse drive ratio is being established only one of the servomotors in the clutch mechanism and the low gear brake mechanism is actuated initially, the second servomotor being actuated by said sequence valves thereafter to enable a smooth engagement of reverse drive ratio even though an increased line pressure is used for reverse drive ratio.
Inventors
- 👤 R Lemon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:05
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/02; F16H61/0262; F16H61/0265; F16H61/0267; F16H61/04; F16H61/06; F16H61/065; F16H61/067
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
248 words
A hydraulic control system for an automatic transmission for vehicles, the transmission including an input shaft and an output shaft and the planetary gearing connected between said shafts, a plurality of fluid actuatable engageable deviceS adapted to produce a plurality of drive ratios by selective engagement thereof one of said devices comprising a first clutch, certain of said drive ratios being established by engagement of said first clutch, one of said drive ratios being a direct drive ratio, another of said engageable devices comprising a second clutch engageable to provide said direct drive ratio, a source of pressure for said control system, means in said control system developing a fluid pressure signal responsive to vehicle speed and engine torque, valve means in said control system interconnected between said source and said engageable devices so as to be actuatable to selectively connect said source to said engageable devices, a hydraulic accumulator provided in each of the connections between said valve means and said first and second clutch devices, said accumulators having a piston, said piston having at least two pressure responsive surfaces thereon, the pressure being supplied to engage said clutch mechanisms being applied to one of said pressure responsive surfaces and said vehicle speed and engine torque signal being applied to said other surface, whereby the torque capacity buildup of said friction devices is delayed by said accumulators and the engagement of each of said clutch mechanisms will be controlled in accordance with vehicle speed and engine torque.
Claim 2
Dependent Claim
248 words
A hydraulic control system for an automatic transmission for vehicles, the transmission including an input shaft and an output shaft and the planetary gearing connected between said shafts, a plurality of fluid actuatable engageable deviceS adapted to produce a plurality of drive ratios by selective engagement thereof one of said devices comprising a first clutch, certain of said drive ratios being established by engagement of said first clutch, one of said drive ratios being a direct drive ratio, another of said engageable devices comprising a second clutch engageable to provide said direct drive ratio, a source of pressure for said control system, means in said control system developing a fluid pressure signal responsive to vehicle speed and engine torque, valve means in said control system interconnected between said source and said engageable devices so as to be actuatable to selectively connect said source to said engageable devices, a hydraulic accumulator provided in each of the connections between said valve means and said first and second clutch devices, said accumulators having a piston, said piston having at least two pressure responsive surfaces thereon, the pressure being supplied to engage said clutch mechanisms being applied to one of said pressure responsive surfaces and said vehicle speed and engine torque signal being applied to said other surface, whereby the torque capacity buildup of said friction devices is delayed by said accumulators and the engagement of each of said clutch mechanisms will be controlled in accordance with vehicle speed and engine torque.
Claim 3
Dependent Claim
88 words
A control system as claimed in claim 1 wherein said torque and speed signal producing means comprises a first valve connected to said source of pressure and movable in accordance with the engine throttle opening so as to produce a signal responsive to engine torque, a second valve connected to said source and developing a signal responsive to the speed of the vehicle, said second valve being connected to said first valve whereby the signal produced by said first valve varies with both vehicle speed and engine torque.
Claim 4
Dependent Claim
74 words
A control system as claimed in claim 2 wherein said plurality of engageable devices includes a brake mechanism engageable to provide in conjunction with said first clutch one of said drive ratios, an additional accumulator connected between said brake mechanism and said source, said additional accumulator also being connected to said vehicle speed and engine torque signal whereby engagement of said brake mechanism will be controlled in accordance with vehicle speed and engine torque.
Claim 5
Dependent Claim
303 words
A hydraulic control system for an automatic transmission for vehicles, the transmission including an input shaft and an output shaft and gearing connected between said shafts, a plurality of fluid actuatable engageable devices producing a plurality of drive ratios through said gearing by selective engagement thereof, at least one of said devices being engageable to establish either a forward or a reverse drive ratio, a pair of hydraulic servomotors associated with said one device, one of said hydraulic servomotors being actuated by said control system for said forward drive ratio and both of said servomotors being actuated by said control system for reverse drive ratio to provide increased engaging force, a source of pressure for said control system, a first valve means in said control system, a fluid connection between said first valve means and said one servomotor, a second valve means between said fluid connection and the other of said servomotors, said first valve means reducing the pressure from said source and supply same to said fluid connection and said one servomotor when said forward ratio is established; said source being connected to said fluid connection exclusive of said first valve means when said reverse ratio is established, said second valve means normally being in a position interrupting the connection between said other servomotor and said fluid connection, said second valve means being actuatable by the pressure in said fluid connection between said source and said other servomotor when reverse ratio is established since the pressure in said connection is not reduced by said first valve means whereby saiD second valve means will open communication to said other servomotor whereby a smooth shift is provided when reverse ratio is established since initially only said one servomotor will be actuated and subsequently said other servomotor will be actuated by said second valve means.
Claim 6
Dependent Claim
303 words
A hydraulic control system for an automatic transmission for vehicles, the transmission including an input shaft and an output shaft and gearing connected between said shafts, a plurality of fluid actuatable engageable devices producing a plurality of drive ratios through said gearing by selective engagement thereof, at least one of said devices being engageable to establish either a forward or a reverse drive ratio, a pair of hydraulic servomotors associated with said one device, one of said hydraulic servomotors being actuated by said control system for said forward drive ratio and both of said servomotors being actuated by said control system for reverse drive ratio to provide increased engaging force, a source of pressure for said control system, a first valve means in said control system, a fluid connection between said first valve means and said one servomotor, a second valve means between said fluid connection and the other of said servomotors, said first valve means reducing the pressure from said source and supply same to said fluid connection and said one servomotor when said forward ratio is established; said source being connected to said fluid connection exclusive of said first valve means when said reverse ratio is established, said second valve means normally being in a position interrupting the connection between said other servomotor and said fluid connection, said second valve means being actuatable by the pressure in said fluid connection between said source and said other servomotor when reverse ratio is established since the pressure in said connection is not reduced by said first valve means whereby saiD second valve means will open communication to said other servomotor whereby a smooth shift is provided when reverse ratio is established since initially only said one servomotor will be actuated and subsequently said other servomotor will be actuated by said second valve means.
Claim 7
Dependent Claim
23 words
A hydraulic control system as claimed in claim 4 wherein said second valve means includes bias means urging same to said interrupting position.
Claim 8
Dependent Claim
17 words
A hydraulic control system as claimed in claim 4 wherein said one device comprises a brake mechanism.
Claim 9
Dependent Claim
60 words
A hydraulic control system as claimed in claim 4 including a manual valve mechanism between said source and said first valve means and said fluid connection, said manual valve means connecting said source to said first valve means for said forward drive ratio, and said manual valve mechanism connecting said source to said fluid connection for said reverse drive ratio.
Claim 10
Dependent Claim
47 words
A hydraulic control system as claimed in claim 4 wherein a third valve means is connected between said first valve means and said fluid connection, said third valve means being responsive to fluid signals to either connect or disconnect said first valve means to said fluid connection.
Claim 11
Dependent Claim
40 words
A hydraulic control system as claimed in claim 8 wherein means are provided to produce a fluid signal responsive to vehicle speed and said vehicle speed signal being operatively connected to said third valve means to control the position thereof.
Claim 12
Dependent Claim
39 words
A hydraulic control system as claimed in claim 9 wherein said vehicle speed signal increases with increasing vehicle speed thereby preventing connection of said first valve means to said fluid connection when said vehicle speed exceeds a predetermined minimum.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-09 | 1977-01-08 | 1977-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-09 | 1981-01-08 | 1981-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-09 | 1985-01-08 | 1985-07-10 | $7700.00 | Window Closed / Lapsed |