perpendicular to the first direction for generating a second operation command signal and a mode selector selectable at least between a first mode and a second mode for generating a mode selection signal a controller receives the first and second operation command signals and the mode selection signal for controlling different motor grader functions depending upon an input combination of the first and second operation command signals and the mode selection signal application_number US 9065293 A description referring now to fig3 there is illustrated the preferred embodiment of an operator 39 s cabin or a cockpit 20 of a motor grader according to the present invention at both sides of a driver seat 21 a left operation lever assembly 22 and a right operation lever assembly 23 are arranged the left and right operation lever assemblies 22 and 23 include operation levers 22a and 23a which can be manually operated by an operator also a steering wheel 24 is positioned in front of the operator seat 21 the steering wheel 24 is supported on a supporting column 25 the left and right operation lever assemblies 22 and 23 include electric signal generators such as potentiometers for generating electric signals according to operation of the left and right operation levers 22a and 23a the left and right operation levers 22a and 23a are designed to be operated in back and forth direction a left and right direction and in oblique directions i e directions intermediate between the back and forth direction and left and right direction electric signals are generated in response to operation of the operation levers 22a and 23a representative of.