US3752015A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic control system for automatic speed changing devices
Assignee: Aisin Corp
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Filing: 1971-07-12
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Granted: 1973-08-14
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Expires: 1991-07-12
Abstract
Abstract In an automatic speed changing device such as an automotive power transmission in which there is provided at least first friction engaging means to complete a low speed ratio power train therethrough and second friction engaging means to complete a high speed ratio power train and, a hydraulic control system therefor is equipped with a closely cooperating pair of pressure reducing valves. The fluid pressure being delivered as desired to the first and second friction engaging means from manual valve means for a shift from one speed ratio to another is controlled by the pressure reducing valves to prevent shocks due to the transition.
Inventors
- 👤 N Murakami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:28
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/04; F16H61/06; F16H61/065; F16H3/00; F16H3/44; F16H3/62; F16H3/66; F16H3/663; F16H2200/00; F16H2200/20; F16H2200/2002; F16H2200/2005; F16H61/68; F16H61/684; F16H61/686
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
350 words
In a speed changing device comprising an input shaft, an output shaft, a plurality of selectively employable power trains between said input shaft, and at least first and second friction engaging means adapted respectively for completing a lower and a higher speed ratio power train through the speed changing device, said first friction engaging means having an actuating chamber and a releasing chamber, and said second friction engaging means having an actuating chamber, a hydraulic control system for said speed changing device comprising a source of fluid pressure, a first passage for hydraulically connecting said source of fluid pressure to said actuating chamber of said first friction engaging means, a second passage for hydraulically connecting said source of fluid pressure to said releasing chamber of said first friction engaging means and to said actuating chamber of said second friction engaging means, shift valve means positioned in said first and second passages for controlling said first and second passages so as to selectively engage and disengage said first and second friction engaging means in order to establish a desired power train, a third fluid passage between said actuating chamber of said first friction engaging means and a point of fluid discharge, pressure reducing valve means disposed in said third fluid passage for on-off controlling the same, said pressure reducing valve means comprising a first pressure reducing valve and a second pressure reducing valve, and a fourth fluid passage for directing to said first and second pressure reducing valves the fluid pressure being delivered to said releasing chamber of said first friction engaging means and to said actuating chamber of said second friction engaging means, said first pressure reducing valve being urged so as to open said third fluid passage by the fluid pressure in said fourth fluid passage when the fluid pressure in said fourth fluid passage reaches a first predetermined value and said second pressure reducing valve being urged so as to close said third fluid passage by the fluid pressure in said fourth fluid passage when the fluid pressure in said fourth fluid passage reaches a second predetermined value.
Claim 2
Dependent Claim
350 words
In a speed changing device comprising an input shaft, an output shaft, a plurality of selectively employable power trains between said input shaft, and at least first and second friction engaging means adapted respectively for completing a lower and a higher speed ratio power train through the speed changing device, said first friction engaging means having an actuating chamber and a releasing chamber, and said second friction engaging means having an actuating chamber, a hydraulic control system for said speed changing device comprising a source of fluid pressure, a first passage for hydraulically connecting said source of fluid pressure to said actuating chamber of said first friction engaging means, a second passage for hydraulically connecting said source of fluid pressure to said releasing chamber of said first friction engaging means and to said actuating chamber of said second friction engaging means, shift valve means positioned in said first and second passages for controlling said first and second passages so as to selectively engage and disengage said first and second friction engaging means in order to establish a desired power train, a third fluid passage between said actuating chamber of said first friction engaging means and a point of fluid discharge, pressure reducing valve means disposed in said third fluid passage for on-off controlling the same, said pressure reducing valve means comprising a first pressure reducing valve and a second pressure reducing valve, and a fourth fluid passage for directing to said first and second pressure reducing valves the fluid pressure being delivered to said releasing chamber of said first friction engaging means and to said actuating chamber of said second friction engaging means, said first pressure reducing valve being urged so as to open said third fluid passage by the fluid pressure in said fourth fluid passage when the fluid pressure in said fourth fluid passage reaches a first predetermined value and said second pressure reducing valve being urged so as to close said third fluid passage by the fluid pressure in said fourth fluid passage when the fluid pressure in said fourth fluid passage reaches a second predetermined value.
Claim 3
Dependent Claim
61 words
The hydraulic control system according to claim 1, in which, said first pressure reducing valve is adapted to control said third fluid passage extending between said actuating chamber of said first friction engaging means and said second pressure reducing valve, and said second pressure reducing valve is adapted to control said point of fluid discharge included in said third fluid passage.
Claim 4
Dependent Claim
65 words
The hydraulic control system according to claim 2, in which each of said first and second pressure reducing valves includes a spring member to offer resistance against the fluid pressure delivered by said fourth fluid passage, the resistive force of said spring member of said first pressure reducing valve being smaller than the resistive force of said spring member of said second pressure reducing valve.
Claim 5
Dependent Claim
182 words
The hydraulic control system according to claim 2, in which said first pressure reducing valve comprises a piston member slidably received In a bore and having at least two lands, a first fluid chamber on one side of said piston member communicating with the said fourth fluid passage, a second fluid chamber between said lands of said piston member, and a third fluid chamber on the other side of said piston member accommodating a spring member which is adapted to offer resistance against the fluid pressure applied to said piston member from said fourth fluid passage, and said second pressure reducing valve comprises a piston member slidably received in a bore and having at least two lands, a first fluid chamber on one side of said piston member communicating with said fourth fluid passage, a second fluid chamber between said lands of said piston member, and a third fluid chamber on the other side of said piston member accommodating a spring member which is adapted to offer resistance against the fluid pressure applied to said piston member from said fourth fluid passage.
Claim 6
Dependent Claim
50 words
The hydraulic control system according to claim 4, in which said third fluid passage includes said actuating chamber of said first friction engaging means, said second fluid chamber of said first pressure reducing valve, said second fluid chamber of said second pressure reducing valve, and said point of fluid discharge.
Claim 7
Dependent Claim
102 words
The hydraulic control system according to claim 1, in which said shift valve means is so arranged that when the same is set in a position to complete a lower speed ratio, the fluid pressure from said source is delivered to said actuating chamber of said first friction engaging means through said first passage, and that when said shift valve means is set in a position to establish a higher speed ratio, the fluid pressure is delivered to said releasing chamber of said first friction engaging means and to said actuating chamber of said second friction engaging means through said second passage.
Claim 8
Dependent Claim
85 words
The hydraulic control system according to claim 6, in which said shift valve means is associated with a second valve means operated in accordance with the relationship between the pressure regulated by throttle valve means responsive to the throttle opening of an engine coupled to said input shaft of said speed changing device and the pressure of governor valve means fixedly mounted on said output shaft of said speed changing device so as to be responsive to the speed of rotation of said output shaft.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |