Patent ID: 8047310

Claim:
A walk-behind or ride-behind self-propelled vehicle comprising: a chassis; first and a second drive wheels coupled to opposing sides of the chassis for propelling the vehicle over a ground surface; first and second hydraulic pumps coupled to the chassis and operable to power the first and second drive wheels, respectively; an engine attached to the chassis and operatively coupled to the hydraulic pumps, the engine configurable to deliver a constant level of output; first and second control levers pivotally attached to the chassis and operable to independently vary, while the engine maintains the constant level of output, a velocity of the first and second drive wheels, respectively, each control lever movable incrementally between a first position corresponding to zero velocity of its respective drive wheel, and a second position corresponding to a maximum forward velocity of its respective drive wheel; a bellcrank pivotally coupled to the chassis, the bellcrank pivotable in response to movement of one of the control levers; an arm attached to one of the hydraulic pumps, wherein the arm and the bellcrank are connected via a pin passing through elongate slots formed in both the bellcrank and the arm; and a drive velocity adjustment lever pivotally attached to the chassis and operatively coupled to both the first and second control levers, the velocity adjustment lever movable, while the engine maintains the constant level of output, between: a first setting wherein the maximum forward velocity of each drive wheel, when its respective control lever is in the second position, is limited to a first predetermined value; and a second setting wherein the maximum forward velocity of each drive wheel, when its respective control lever is in the second position, is limited to a second predetermined value greater than the first predetermined value.