Patent ID: 8230753
Filing Date: 2012-07-31
Classification: F16H,Y10T

Abstract:
1. A multiple speed ratio power transmission mechanism for an engine powered vehicle having multiple gear ratio gearing, a mainshaft and range gearing with high and low ratio ranges; two separate countershaft assemblies including separate countershafts and multiple mainshaft gears on the mainshaft, each countershaft assembly having at least one countershaft gear element engageable with separate mainshaft gears; two power input shafts; each power input shaft being drivably geared to a separate one of the countershaft assemblies; dual clutches for selectively establishing and disestablishing driving torque delivery to each power input shaft; gear ratio change clutches for selectively establishing torque flow paths through the multiple gear ratio gearing; one torque flow path through the multiple speed ratio gearing being established and another of the torque flow paths being preselected as the dual clutches are engaged and disengaged; the range gearing comprising a first range gear connected to a power output shaft and a second range gear, the first and second range gears being supported on the mainshaft; a range gearing countershaft having a first countershaft gear element and a second countershaft gear element engaging, respectively, the first and second range gears; gear ratio change clutches for establishing torque flow paths through the multiple speed ratio gearing; and a high ratio range clutch for selectively connecting the first range gear to the mainshaft to establish high ratio range operation and a low ratio range clutch for selectively connecting the second range gear to the mainshaft to establish low ratio range operation.