Hydraulic control system for automatic transmission

Claim 2

In an automatic transmission for a motor vehicle having a driving member, a driven member, a plurality of planetary gear sets drivably connected with said driving and driven members by means of a shaft and clutch and brake means for controlling the relative motion of the planetary gear sets, the clutch and brake means including a reverse high clutch and a low reverse reaction brake for placing the planetary gear sets in reverse drive, a hydraulic control system comprising a source of hydraulic pressure; and a manual selector valve communicating with said source of hydraulic pressure and having a conduit communicating with said low reverse brake when said automatic transmission is set in its neutral position, whereby when the manual selector valve is shifted from neutral to reverse position the reverse high clutch transmits power from the driving member to the sun gear of a planetary gear set and the low reverse reaction brake acts to hold the planet carrier of said gear set stationary so as to cause the ring gear of said gear set and the driven member to rotate in reverse.

Claim 3

A hydraulic control system according to claim 1 including governor valve means forming a source of governor pressure and a 1-2 shift valve communicating with said sourcE of governor pressure and with said manual selector valve, said 1-2 shift valve having a valve spool and a speed responsive means for holding said valve spool in a first position when said speed responsive pressure is below a predetermined level and in a second position when said speed responsive pressure exceeds said predetermined level, said valve spool blocking fluid communication between said low reverse reaction brake and said manual selector valve when said 1-2 shift valve is in said second position, whereby said 1-2 shift valve passing pressurized fluid from said manual selector valve to said low reverse reaction brake when said selector valve is in the neutral position and does not pass pressurized fluid to said low reverse reaction brake when said manual selector valve is from the drive to the neutral position when said vehicle is at high speed.

Claim 4

In an automatic transmission for a motor vehicle having a driving member; a driven member; a first and second planetary gear set each having toothed members comprising an outer ring gear, at least two planet pinions carried by a carrier and meshing with said outer gear and a sun gear externally meshing with said planet pinions; a shaft connecting said sun gears of said first and second gear sets to each other; shaft means connecting said first and second planetary gear set with said driving member and said driven member, and clutch and brake means for controlling the relative motion of said planetary gear sets, the clutch and brake means including a reverse high clutch and a low reverse reaction brake means for operatively connecting said reverse high clutch and reverse reaction brake to said driving member and the shaft connecting said sun gears for placing the planetary gear sets in reverse drive, a hydraulic control system comprising a source of hydraulic pressure, and a manual selector valve communicating with a source of hydraulic pressure and having a conduit communicating with said low reverse brake when said automatic transmission is set in its neutral position, whereby when the manual selector valve is shifted from neutral to reverse position the reverse high clutch is coupled and transmits power to the sun gear of said second gear set through the brake drum and the reverse reaction brake is applied, the pinion carrier of the second gear set is held stationary by said brake, the pinions of said second gear set idle away causing the outer ring gear of said second gear set and the driven member to reverse direction.

Claim 5

In an automatic transmission for a motor vehicle having a driving member; a driven member; a first and second planetary gear set each having toothed members comprising an outer ring gear, at least two planet pinions carried by a carrier and meshing with said outer gear and a sun gear externally meshing with said planet pinions; a shaft connecting said sun gears of said first and second gear sets to each other; shaft means connecting said first and second planetary gear set with said driving member and said driven member, and clutch and brake means for controlling the relative motion of said planetary gear sets, the clutch and brake means including a reverse high clutch and a low reverse reaction brake means for operatively connecting said reverse high clutch and reverse reaction brake to said driving member and the shaft connecting said sun gears for placing the planetary gear sets in reverse drive, a hydraulic control system comprising a source of hydraulic pressure, and a manual selector valve communicating with a source of hydraulic pressure and having a conduit communicating with said low reverse brake when said automatic transmission is set in its neutral position, whereby when the manual selector valve is shifted from neutral to reverse position the reverse high clutch is coupled and transmits power to the sun gear of said second gear set through the brake drum and the reverse reaction brake is applied, the pinion carrier of the second gear set is held stationary by said brake, the pinions of said second gear set idle away causing the outer ring gear of said second gear set and the driven member to reverse direction.