Patent attributes
A system for controlling a torque converter of an automatic transmission driven by a power source, the system including a torque converter an impeller, a turbine driveably connected to a transmission input and able to be driven hydrokinetically by the impeller, a stator, an impeller clutch for alternately engaging and disengaging a drive connection between the impeller and the power source, a source of converter charge pressure communicating with the impeller clutch, a source of converter discharge pressure communicating with the impeller clutch, a magnitude of differential force due to charge pressure and discharge pressure across the impeller clutch alternately producing operating multiple operating states of the impeller clutch, and a orifice having a variable fluid flow area for changing a magnitude of converter discharge pressure.