Patent ID: 6220108
Filing Date: 2001-04-24
Classification: F16H,Y10T

Abstract:
A compound, manually shifted, change-gear transmission system comprising a range-type compound transmission having a main transmission section connected in series with a range-type auxiliary transmission section shiftable to a low-range condition and a high-range condition, a manually operated shift selector allowing selection of a plurality of low-range ratios and a plurality of high-range ratios, and range shift sensing means for sensing shift selector operation indicative of an operator'sselection of a shift (a) from a low-range ratio to a high-range ratio and providing a first input signal indicative thereof, and (b) from a high-range ratio to a low-range ratio and providing a second input signal indicative thereof, said system characterized by:a speed sensor for sensing the value of a parameter indicative of vehicle speed and providing a third input signal having a magnitude indicative thereof;an actuator responsive to command output signals for causing said range section to be shifted to a selected one of said low-range and high-range conditions;a controller for receiving a plurality of input signals including said first, second and third input signals and processing same in a predetermined manner to issue command output signals to at least said actuator, said controller commanding a shift into the low-range condition only upon sensing (a) said shift selector operation indicative of an operator's selection of a shift from a high-range ratio to a low-range ratio and (b) the magnitude of said third input signal being less than a first reference.