Steering and Driving Systems and Related Vehicles

Abstract

A ZTR vehicle includes true or proper ZTR steering in the forward and reverse directions. The vehicle has independently driven locomotive drives that drive the wheels to provide mobility and steering to the vehicle. A steering wheel is included that pivots one of two steering input members that rotate to independently shift the drive units. A speed and direction pedal is also included, which is communicated to provide direction and magnitude input to the drive units. The steering input and speed and direction inputs coordinate propelling the vehicle such the vehicle turns in the same direction when traveling forward as well as in reverse.

1 . A steering and drive control mechanism for a zero turn radius vehicle that includes a vehicle chassis and a pair of transmission systems for independently driving at least two traction elements that are spaced from each other and each define two parallel drive directions for driving said vehicle, said steering and drive control mechanism comprising
 a drive assembly comprising
 a pivoting member mounted to pivot about a pivot axis relative said chassis, 
 a pair of control linkage members engaged to the pivoting member in a movable manner so that the connection point for each control linkage member with said pivoting member can be moved relative said pivot axis, each said control linkage member in operative connection with a respective transmission systems to control the respective transmission system, 
 a foot operated pedal assembly, operatively coupled to the drive assembly so that movement of the pedal assembly results in pivotal movement of the pivoting member about the pivot axis; 
 a steering member pivotally connected to the vehicle chassis, 
 a steering assembly coupling the steering member with the control linkage members so that pivoting movement of the steering member can vary the position of one or both of the connection points of the control linkage members relative the pivot axis to thereby effect a change in operation of one of both of the transmission systems. 
   
   
   
       2 . The steering and drive control mechanism as claimed in  claim 1  wherein the location of each of the connection points at the pivoting member of each of the control linkage members can be varied by independently. 
   
   
       3 . The steering and drive control mechanism as claimed in  claim 1  wherein biasing means is provided to bias the control linkage members to a location relative the pivoting member where the location of the connection points in the same distance from the pivot axis. 
   
   
       4 . The steering and drive control mechanism as claimed in  claim 1  wherein each said control linkage member is mounted relative said chassis by a mount that allow the control linkage member to displace in a manner rotationally unconstrained by said mount upon (a) the rotation of said pivoting member about the pivot axis and/or (b) movement of the steering member to vary the position of one or both of the connection points of the control linkage members relative the pivot axis. 
   
   
       5 . The steering and drive control mechanism as claimed in  claim 1  wherein the traction elements be wheels. 
   
   
       6 . The zero turning radius lawnmower that includes the mechanism as claimed in  claim 1 . 
   
   
       7 . The zero turning radius lawnmower, said lawnmower comprising
 a pair of transmissions to drive at least two drivers independently of each other;   a chassis;   a steering and drive control mechanism as claimed in  claim 1 .   
   
   
       8 . The lawnmower as claimed in  claim 7  wherein the steering member is a steering wheel. 
   
   
       9 . A control mechanism to control the speed and direction of travel of a vehicle that includes a steering wheel and an accelerator pedal, said vehicle capable of being propelled by two spaced apart traction elements each independently driven by a respective motor, the output torque of each motor controlled by a displaceable input device, said control mechanism comprising;
 a first push-pull rod having a first distal end and a second distal end, said first distal end engaged to said input device of one of said motors (hereinafter “first motor”),   a second push-pull rod having a first distal end and a second distal end, said first distal end engaged to said input device of the other of said motors (hereinafter “second motor”),   a pivot member mounted from said vehicle pivotable about a pivot axis in a manner responsive to the position of the accelerator pedal, said pivot member including at least one lever arm to which and along at least part of which at least one of said first and push-pull rod members and second push-pull rod members can traverse by being slidingly coupled thereto at or towards said second distal end, such that when said pivot member is pivoted about pivot axis, the first push-pull rod can, when in at least one position along said lever arm, displace the input device of said first motor and said second push-pull rod can, when in at least one position along said lever arm, displace the input device of said second motor,   a first coupling member operatively extending between said steering wheel and said first push-pull rod and   a second coupling member operatively extending between said steering wheel and said second push-pull rod, wherein the movement of said steering wheel is, via said coupling members, capable of displacing both said first push-pull rod and said second push-pull rod along said lever arm to displace first push-pull rod and/or said second push-pull rod relative said pivot axis to thereby change the effective lever arm effect of said pivot member on said first push-pull rod and/or said second push-pull rod and thereby vary its effect on its respective input device.   
   
   
       10 . The mechanism as claimed in  claim 9  wherein the pivot member includes two lever arms, one for each of said first push-pull rod and said second push-pull rod, each said lever arm movable in unison.