Patent ID: 7059433

Claim:
A riding lawn mower comprising: a vehicle chassis; a driver's seat supported by said vehicle chassis; a prime mover supported by said vehicle chassis behind said seat; a mower unit supported by said vehicle chassis and driven by said prime mover; a caster supported by said vehicle chassis before said seat; a pair of drive wheels supported by said vehicle chassis behind said seat; a transmission casing fixed to said vehicle chassis; a first hydrostatic stepless transmission disposed in said transmission casing and drivingly connected to said prime mover and said drive wheels, wherein a change in direction and amount of fluid delivery within said first hydrostatic stepless transmission symmetrically drives said pair of drive wheels at various speeds forward and backward; a second hydrostatic stepless transmission disposed in said transmission casing and drivingly connected to said prime mover and said drive wheels, wherein a change in direction and amount of fluid delivery within said second hydrostatic stepless transmission differentially drives said pair of drive wheels at various relative speed; a steering means supported by said vehicle chassis and operatively connected to said second hydrostatic stepless transmission, wherein said steering means changes the direction and amount of fluid delivery within said second hydrostatic stepless transmission; and a speed controlling means operatively connected to said first hydrostatic stepless transmission, wherein said speed controlling means changes the direction and amount of fluid delivery within said first hydrostatic stepless transmission.