Abstract: A look-up control system for a lock-up type automatic transmission wherein a torque converter locks up in a pattern when the engine temperature is higher than a predetermined temperature value, but is prevented from locking up in the pattern when the engine temperature is lower than the predetermined temperature value. During engine operation when the engine temperature is lower than the predetermined temperature value, the torque converter is allowed to lock up in a second pattern or prevented from locking up.

Abstract: The control system controls a lock-up type automatic transmission such that the forced lock-up of a lock-up torque converter is released only after a predetermined condition after the supply of fuel to the engine has been resumed by a fuel supplying means.

Abstract: An indicator system includes an indicator mounted near a driver's seat and arranged to be responsive to a lock-up permission signal which is to appear when the vehicle is operating within a lock-up range.

Abstract: A gear shift control system for an automatic transmission comprises an air flow sensor for sensing the quantity of air taken into an internal combustion engine and supplying a corresponding electrical signal to a differentiator which provides a derivative of the sensed intake air quantity. A vehicle speed sensor senses the speed of rotation of the engine crankshaft to generate a corresponding signal. A gear shift decision circuit is receptive of signals from the air flow sensor and vehicle speed sensor to define a gear shift control line on a two-dimensional coordinate system as a function of the received input signals on respective coordinate axes. The derivative of the sensed air quantity is used to shift the gear shift control line to a higher speed side of the coordinate system to permit the transmission to effect downshift operation.

Abstract: A speed-change control system for an automatic transmission includes a vehicle speed sensor, an engine load sensor, speed change program memory circuits, a comparator for comparing signals from the sensors with signals from the memory circuit, and a speed change control circuit for producing a signal for changing the transmission into a determined speed position in response to an output from the comparator.

Abstract: A tandem master cylinder assembly for use in split-type hydraulic brake systems of an automotive vehicle, comprising a fluid reservoir, a cylinder body having a cylinder bore communicable with the fluid reservoir through two ports formed in the cylinder body, primary and secondary pistons axially slidable as a single unit in the cylinder bore, a floating piston axially movable within the secondary piston and forming, jointly with the primary and secondary pistons, primary and secondary pressure chambers which are variable in volume depending upon the axial positions of the primary and secondary pistons relative to the cylinder body and the axial position of the floating piston relative to the cylinder body and to the secondary piston, and means to limit the distance of travel of the floating piston relative to the cylinder body.

Abstract: A vehicle braking system includes a pressure modulating valve interposed in the pressure fluid line between a master cylinder and the rear wheel brake cylinders. The pressure modulating valve comprises a valve seat fluidly disposed in a valve body intermediate an inlet port of the valve body and an outlet port thereof, an inertia ball capable of seating against the valve seat, and apparatus for increasing the magnitude of the vehicle deceleration at which the inertia ball seats against the valve seat in response to an increase of master cylinder pressure.