Abstract: A mechanically adjustable variable speed drive includes an electric actuation apparatus which can be controlled by an analog embodiment or a digital circuitry embodiment. A speed change actuator is automatically and mechanically adjustable, such as with a controlled servomotor. A tachometer determines the actual rotational speed of a drive shaft, which is compared in a digital controller with a manually set desired rotational output speed. The digital controller (or an analog circuit in the case of the analog embodiment) controls the servomotor to adjust the mechanically adjustable variable speed drive. An automatic deadband means inhibits driving of the servomotor whenever the tachometer signal and the desired speed setting signal is within a predetermined deadband, which deadband is adaptively changed responsive to various conditions.

Abstract: In a hydraulic control system for an automatic power transmission for an automotive vehicle, a line pressure booster valve is provided to boost the line pressure to be developed by the pressure regulator valve of the control system when a downshift is to be made from the highest one of the gear ratios in the automatic forward drive range to the higher one of the gear ratios in a manual forward drive range of the transmission system.

Abstract: A compound column for absorbing the energy of impact at a controlled rate. The compound column is comprised of an outer column, which collapses at a predetermined rate during the initial phase of energy absorption, and an inner column, which prevents buckling of the outer column during this phase. During the second phase of collapse both columns absorb energy, at a higher predetermined rate, by collapsing simultaneously.