A mechanism for controlling the movement of a zero turning radius power
mower includes a single control arm movable in a forward direction and a
rearward direction, and pivotable in a clockwise direction and in a
counterclockwise direction. The control arm is connected via a pair of
control linkages to a right hydraulic pump and to a left hydraulic pump
such that when the control arm is moved in a forward direction the two
hydraulic pumps power the drive wheels forward, and when the control arm
is moved in a rearward direction the two hydraulic pumps power the drive
wheels rearward. When the control arm is pivoted in a clockwise direction
the left hydraulic pump powers the left drive wheel forward and the right
hydraulic pump powers the right drive wheel rearward. When the control
arm is pivoted in a counterclockwise direction the right hydraulic pump
powers the right drive wheel forward and the left hydraulic pump powers
the left drive wheel rearward.