UN CONTROL DE CAMBIO PARA UNA TRANSMISION HIDROMECANICA

摘要

A shift control for a hydromechanical transmission includes a support member having a primary pivot pin carrying side-by-side longitudinally exending range and speed shift quadrants respectively connectible to the transmission to change ranges and speeds. A shift mechanism with a vertically extending shift lever pivots laterally on a main pivot member which is pivotable around the primary pivot pin to allow longitudinal pivotal movement of the shift lever. A guide plate contains a shift pattern cutout in which the shift lever is laterally movable from a neutral position in which latches in the shift lever mechanism prevent both quadrants from moving to a range or speed shift quadrant engaged position where one of the latches respectively releases the range or speed shift quadrant to allow pivotation thereof upon longitudinal movement of the shift lever. The shift pattern cutout is provided with stop cutouts to require a Z shifting pattern to shift between ranges in one direction of longitudinal movement and the shift lever mechanism cooperates with the support member to require the same Z pattern in the opposite direction of longitudinal pivotation. The shift pattern cutout further requires that the speed shift quadrant be in the neutral position for engagement with the shift lever. A high/low lever pivotable by lateral movement of the shift lever mechanism along with longitudinal movement of the shift lever to cause pivotation of the speed shift quadrant provides additional speed shifting. Lockout devices utilizing a cam follower mechanism and a lever arm mechanism operating off the range shift quadrant respectively prevent reverse operation and of certain speeds in predetermined ranges.