Steering system for a zero-turn radius vehicle
AssigneeHydro-Gear Limited Partnership
InventorsDouglas W. Bell, Bryce E. Steenburg
Life of this patent
Estimating the term…
Abstract
A steering apparatus for a zero-turn radius vehicle using a steering mechanism coupled to a first set of wheel assemblies by a plurality of cables. User input to the steering mechanism causes the cables to turn the first set of wheel assemblies about a vertical axis. Specifically, the cables link the steering mechanism to cam mechanisms that are attached to each wheel assembly. The design of the cam mechanism, which preferably includes two cams of varying radii, enables the two wheel assemblies to rotate about their vertical axes at varied degrees of rotation and greater than ninety degrees from the forward facing position, thereby resulting in zero-turn radius capability.
Claims22
A steering apparatus for a vehicle, comprising:
- a steering shaft;
- a plurality of cables, wherein each one of the plurality of cables is engaged to the steering shaft;
- a first cam mechanism comprising a first cam having a first one of the plurality of cables engaged thereto and a second cam having a second one of the plurality of cables engaged thereto;
- a second cam mechanism comprising a third cam having a third one of the plurality of cables engaged thereto and a fourth cam having a fourth one of the plurality of cables engaged thereto;
- wherein each of the first cam mechanism and the second cam mechanism has a first position corresponding to a forward direction of travel of the vehicle and each of the first and second cam mechanisms has a generally vertical axis about which the corresponding cam mechanism can rotate greater than 90 degrees from the first position.
A steering apparatus for steering a vehicle comprising;
- a steering shaft;
- four cables, each cable having a first end connected to the steering shaft and a second end;
- first and second cam mechanisms, each coupled to the second end of two of the four cables, the first and second cam mechanisms having a first and second cam, each cam having a first portion having a radius and a second portion having a radius, wherein the radius of the second portion is greater than the radius of the first portion.
A vehicle steered by a steering apparatus comprising:
- first and second wheel assemblies rotatably disposed on a vehicle frame, wherein the first wheel assembly comprises a first wheel having a first axis of rotation and the second wheel assembly comprises a second wheel having a second axis of rotation;
- a first cam mechanism mounted on the first wheel assembly;
- a second cam mechanism mounted on the second wheel assembly;
- first and second cables disposed on the first cam mechanism;
- third and fourth cables disposed on the second cam mechanism;
- a steering shaft having a circumference around which the four cables are wrapped and to which the four cables are fixedly attached;
- and
- a third wheel and a fourth wheel each driven by a drive device and sharing a common axis of rotation,
- wherein, the first and second wheel assemblies are both capable of being rotated about a respective vertical axis of rotation such that the first axis of rotation and the second axis of rotation intersect at a point located generally proximate to the common axis of rotation of the third and fourth wheels and generally proximate to the center point of the common axis of rotation between the third and fourth wheels, and
- each of first and second cam mechanisms includes a first and second cam, wherein the first and second cam mechanisms have a first position corresponding to a forward direction of travel of the vehicle and each cam mechanism has a generally vertical axis about which the cam mechanism can rotate greater than 90 degrees from the first position.
A steering apparatus for a vehicle, comprising:
- a steering shaft;
- a plurality of cables, wherein a first one of the plurality of cables is engaged to the steering shaft and a second one of the plurality of cables is engaged to the steering shaft;
- a first cam mechanism comprising a first cam and a second cam, wherein the first one of the plurality of cables has a first end that is engaged to the first cam;
- and
- a second cam mechanism comprising a third cam and a fourth cam, wherein the second one of the plurality of cables has a first end that is engaged to the third cam;
- wherein each of the first cam mechanism and the second cam mechanism has a first position corresponding to a forward direction of travel of the vehicle and each of the first and second cam mechanisms has a generally vertical axis about which the corresponding cam mechanism can rotate greater than 90 degrees from the first position in either direction of rotation.
Dependencies are inferred from the claim text.