Double Acting Servo Patents (Class 477/153)
  • Patent number: 5876305
    Abstract: An automatic transmission control system, which includes a 2-4 brake having a servo apply fluid chamber and a servo release fluid chamber and a 3-4 clutch having a fluid chamber and causes a 3-2 shift by engaging the 2-4 brake and disengaging the 3-4 clutch, controls engaging pressure for the 3-4 clutch by way of controlling servo apply pressure for the 2-4 brake to disengage the 3-4 brake so as thereby to increase turbine speed during the 3-2 gear shift and, at near the end of the 3-2 gear shift, brings the 2-4 brake into engagement. During control of disengagement of the 3-4 clutch, the pressure difference between servo apply pressure and servo release pressure is changed to become greater at the beginning of the gear shift.
    Type: Grant
    Filed: September 30, 1997
    Date of Patent: March 2, 1999
    Assignee: Mazda Motor Corporation
    Inventors: Shinya Kamada, Shin Nakano, Mitsukazu Tasaka, Kenji Sawa, Yasunari Nakayama, Mitsuo Yasuno