Apparatus for controlling gear shifts in automatic transmissions

Abstract

To improve vehicle operator comfort and safety and to reduce wear and tear on the automatic transmission, the apparatus prevents an upshift whenever the accelerator pedal is released very quickly. The apparatus stores the load signal which prevailed when the load was abruptly reduced, thereby simulating to the transmission controller a continuation of high load and preventing an undesired upshift, for example in downhill operation and during roll-outs. Normal load signals are restored whenever the accelerator pedal is returned to a predetermined point. In one embodiment, the stored load signal is a hydraulic pressure and in another embodiment, for use with an electronic transmission controller, the load signal is an electrical signal. In a third embodiment, the upshift control signal from the controller to the transmission is interrupted when the apparatus indicates a complete release of the accelerator pedal.

Dependencies are inferred from the claim text.