Lean-steered mountain board and method of operation

Abstract

According to an embodiment, a wheeled vehicle is provided, which includes a frame supporting a rear wheel, a rider's deck, and a steering post lying parallel to a longitudinal axis of the vehicle. A front axle is coupled to the frame and configure to rotate about the steering post while remaining perpendicular to the longitudinal axis. Axle stubs are coupled to respective ends of the axle so as to be pivotable relative to the axle, and front wheels are rotatably coupled to the axle stubs. A steering mechanism is configured to permit a rider to steer the vehicle by leaning on the rider's deck.

1 . A wheeled vehicle, comprising:
 a frame that includes a steering post extending from a front end of the frame and lying parallel to a longitudinal axis of the vehicle;   a deck coupled to the frame, positioned and configured to support a rider standing thereon;   a front axle coupled to the frame and configure to rotate about an axis defined by the steering post while remaining perpendicular to the longitudinal axis; and   first and second axle stubs coupled to respective ends of the axle and configured to be pivotable about respective first and second steering axes, relative to the axle.   
     
     
         2 . The vehicle of  claim 1 , wherein the first and second axle stubs are parts of respective first and second spindles, each pivotably coupled to a respective end of the axle, the vehicle further comprising a tie rod coupled at a first end to the first spindle and at a second end to the second spindle, and configured to constrain the first and second spindles to pivot about the respective pivot axes substantially in unison. 
     
     
         3 . The vehicle, of  claim 2 , comprising:
 a steering linkage block fixed to the frame and configured to pivot therewith relative to the front axle; and   a drag link coupled at one end to the steering linkage block and at an opposite end to a steering arm of the first spindle, configured to cause the first spindle to pivot according to an angle of the frame relative to the axle.   
     
     
         4 . The vehicle, of  claim 2 , comprising:
 first and second front wheels rotatably coupled to respective ones of the first and second axle stubs; and   a rear wheel rotatably coupled to a rear end of the frame.   
     
     
         5 . The vehicle of  claim 2 , wherein the first and second steering axes are tilted relative to the frame such that the first and second spindles each have a positive caster angle. 
     
     
         6 . The vehicle, of  claim 1 , wherein the first and second spindles each have a positive caster angle of more than 30 degree. 
     
     
         7 . The vehicle, of  claim 1 , wherein the frame includes a fork at the rear end of the frame, configured to receive a rear wheel rotatably coupled to the fork via an axle extending between arms of the fork. 
     
     
         8 . The vehicle, of  claim 7 , comprising:
 a rear wheel rotatably coupled to the fork via an axle extending between first and second arms of the fork; and   a braking assembly, including:
 a brake rotor coupled to the rear wheel and configured to rotate therewith, 
 a brake caliper coupled to the first arm of the fork and positioned and configured to apply a braking force to the rotor, 
 a brake control handset, and 
 a brake cable coupled at a first end to the brake control handset and at a second to the brake caliper, and configured to transmit squeezing force from the brake control handset to the brake caliper. 
   
     
     
         9 . The vehicle, of  claim 1 , comprising a steering return assembly configured to bias the first and second axle stubs toward a centered steering position. 
     
     
         10 . The vehicle of  claim 9  wherein the steering return assembly includes a torsion plate fixed to the frame and configured to pivot therewith relative to the front axle; and
 Elastomeric bushings positioned on opposite sides of the torsion plate and arranged such that when the frame rotates, relative to the axle, away from a centered position, the torsion plate applies an angled compressive force to the bushings, which resist the compressive force, thereby applying a centering bias to the torsion plate. 
 
     
     
         11 . The vehicle of  claim 10 , wherein:
 the steering return assembly comprises:
 a coupling link having a first end coupled to the axle; and 
 a linking rod having a first end coupled to a second end of the coupling link, extending through a transverse aperture in the torsion plate and upon which the elastomeric bushings are positioned. 
   
     
     
         12 . A steering assembly for a wheeled vehicle, comprising:
 an axle, including first and second spindle brackets affixed to the respective ends of the axle;   a steering tube fixed to the axle and crossing the axle at a center thereof, a central axis of the steering tube defining a horizontal axis of the steering assembly;   first and second spindles pivotably coupled to respective ones of the first and second spindle brackets, and configured to pivot about respective steering axes, the steering axes having a caster angle of greater than five degrees, relative to a vertical axis normal to the horizontal axis; and   a tie rod extending between the first and second spindles and configured to constrain them to pivot about the respective first and second steering axes in unison.   
     
     
         13 . The steering assembly of  claim 12 , wherein the caster angle is at least 15 degrees. 
     
     
         14 . The steering assembly of  claim 12 , wherein the caster angle is at least 30 degrees. 
     
     
         15 . The steering assembly of  claim 12 , comprising a steering return assembly configured to bias the steering assembly toward a centered steering position.