Steering system and utility vehicle incorporating same

Patent metadata

Field	Value
Publication number	US-9623903-B2
Application number	US-201514697909-A
Country	US
Kind code	B2
Filing date	Apr 28, 2015
Priority date	Apr 28, 2015
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

A grounds maintenance vehicle such as a stand-on spreader/sprayer and a steering system for use with the same. In one embodiment, the steering system includes a laterally swinging control handle accessible by an operator standing on a platform of the vehicle. The handle controls movement of one or more steerable wheels such that lateral swinging of the control handle toward a left side results in a corresponding left turn, while lateral swinging of the control handle toward a right side results in a corresponding right turn.

First claim

What is claimed is:

1. A utility vehicle comprising:
a chassis comprising a front end and a rear end;
at least one front wheel rotatably coupled to the front end of the chassis, wherein the front wheel is adapted to rotate about an axle attached to a steering knuckle, the steering knuckle adapted to pivot, relative to the chassis, about a steer axis;
a steering system comprising:
a control member comprising a first end defining an operator control handle, and a second end pivotally connected to the chassis such that the control member is pivotable, relative to the chassis, about a pivot axis;
a lever arm connected to the control member at or near the second end, the lever arm comprising a distal end spaced-apart from the pivot axis; and
a connecting element attached to the distal end of the lever arm and to the steering knuckle;
wherein the steering system proportionally converts lateral movement of the control handle to pivoting of the front wheel about the steer axis.

2. The vehicle of claim 1 , wherein the control member comprises a pivot shaft and a control arm, the pivot shaft forming the second end of the control member.

3. The vehicle of claim 2 , wherein at least a portion of the control arm extends upwardly and rearwardly from the pivot shaft.

4. The vehicle of claim 1 , wherein the chassis further defines a longitudinal axis extending between the front and rear ends of the chassis, wherein the pivot axis is parallel to the longitudinal axis.

5. The vehicle of claim 1 , further comprising a material application apparatus attached to the chassis.

6. The vehicle of claim 5 , wherein the material application apparatus comprises one or both of a granular material spreader and a liquid sprayer.

7. The vehicle of claim 1 , further comprising at least one rear wheel rotatably coupled to the chassis and powered by a prime mover supported by the chassis.

8. The vehicle of claim 1 , wherein the operator control handle comprises a speed control input.

9. The vehicle of claim 1 , wherein the pivot axis is located at an elevation at or near an elevation of the axle.

10. The vehicle of claim 1 , further comprising an operator support platform attached to the chassis.

11. A utility vehicle comprising:
a chassis comprising a front end, a rear end, and a longitudinal axis extending between the front and rear ends;
at least one front wheel rotatably coupled to the front end of the chassis, wherein the front wheel is adapted to rotate about an axle attached to a steering knuckle, the steering knuckle adapted to pivot, relative to the chassis, about a steer axis;
a steering system comprising:
a pivot shaft pivotally coupled to the chassis such that the pivot shaft pivots about a pivot axis that is parallel to the longitudinal axis;
a control arm comprising a first end defining an operator control handle, and a second end connected to the pivot shaft;
a lever arm also connected to the pivot shaft, the lever arm comprising a distal end spaced-apart from the pivot axis; and
a connecting rod attached to the distal end of the lever arm and to the steering knuckle;

wherein the steering system proportionally converts lateral movement of the control handle to pivoting of the front wheel about the steer axis.

12. The vehicle of claim 11 , wherein the control handle comprises operator controls adapted to selectively change a rotational speed and direction of a powered rear wheel.

13. The vehicle of claim 11 , wherein the pivot axis is located at an elevation at or near an elevation of the axle of the front wheel.

14. The vehicle of claim 11 , further comprising a material application apparatus supported by the chassis.

15. The vehicle of claim 14 , wherein the material application apparatus comprises one or both of a granular material spreader and a liquid sprayer.

16. The vehicle of claim 11 , further comprising an operator platform attached to the chassis and adapted to support a riding operator.

17. A utility vehicle comprising:
a chassis comprising a front end and a rear end, wherein a longitudinal axis extends along the chassis between the front and rear ends;
a prime mover supported by the chassis;
at least one rear wheel rotatably coupled to the chassis at or near the rear end, wherein the rear wheel is powered by the prime mover to propel the vehicle over a ground surface;
left and right front wheels rotatably coupled to the chassis at or near the front end, wherein: the left front wheel is adapted to rotate about a left axle, the left axle attached to a left steering knuckle that is itself coupled to the chassis at, and pivotable about, a left wheel steer axis; and the right front wheel is adapted to rotate about a right axle, the right axle attached to a right steering knuckle that is itself coupled to the chassis at, and pivotable about, a right wheel steer axis;
a platform attached to the chassis and adapted to support an operator; and
a steering system comprising:
a pivot shaft attached to the chassis and operable to pivot about a pivot axis parallel to the longitudinal axis;
a control arm comprising a second end attached to the pivot shaft, the control arm extending upwardly and rearwardly to terminate at a first end;
a lever arm attached to the pivot shaft;
a left tie rod connected between the lever arm and the left steering knuckle, and a right tie rod connected between the lever arm and the right steering knuckle; and
a control handle attached to the first end of the control arm, wherein lateral movement of the control handle results in proportional pivoting of the left and right front wheels about the left and right steer axes, respectively.

18. The vehicle of claim 17 , wherein the pivot axis is located at an elevation at or near an elevation of one or both of the left and right axles.

19. The vehicle of claim 17 , further comprising a second rear wheel rotatably coupled to the chassis at or near the rear end and transversely spaced-apart from the at least one rear wheel, wherein the second rear wheel is also powered by the prime mover.

20. The vehicle of claim 17 , wherein the platform is located at or near the rear end of the chassis.

21. A utility vehicle comprising:
a chassis comprising a front end and a rear end;
a front wheel rotatably coupled to the front end of the chassis, wherein the front wheel is adapted to rotate about an axle attached to a steering knuckle, the steering knuckle adapted to pivot, relative to the chassis, about a steer axis;
a steering system comprising:
a control member comprising a first end defining an operator control handle, and a second end pivotally connected to the chassis such that the control member is pivotable, relative to the chassis, about a pivot axis;
a position sensor adapted to detect a position of the control member and produce a position signal;
an electronic controller adapted to receive the position signal and calculate a steering angle command signal; and
an actuator operatively connected to the steering knuckle, wherein the actuator is adapted to receive the steering angle command signal and pivot the front wheel about the steer axis in response to the steering angle command signal.

22. The vehicle of claim 21 , further comprising an operator platform attached to the chassis and operable to support a ride-on operator.

23. The vehicle of claim 21 , further comprising a second front wheel adapted to rotate about a second axle attached to a second steering knuckle,

Assignees

• Exmark Mfg Company Incorporated

Inventors

• Cook David Michael
• Busboom Garry W
• Papke Clark S

Classifications

• B62D3/02

  mechanical · CPC title

• B62D1/12

  Hand levers · CPC title

• B62D5/04

  electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear · CPC title

• B62D7/08 Primary

  the pivotal axes being situated in a single plane transverse to the longitudinal centre line of the vehicle · CPC title

• B62D7/20

  Links, e.g. track rods (means for adjusting camber, castor, or toe-in B62D17/00) · CPC title