Two wheel drive for a motorcycle

Abstract

A motorcycle where the rear wheel of the motorcycle is not only driven but the front wheel is also driven. Power from the motor of the motorcycle is transmitted to a power transmitting joint which includes an output shaft. The power transmitting joint is mounted directly below the steering stem and on the steering axis of the motorcycle. The power to the front wheel is supplied through a chain which connects between the steering assembly and the front wheel with the chain being movable in conjunction with the front wheel when the front wheel is steered and with suspension movement as when bumps are encountered.

What is claimed is: 
     
         1 . In combination with a motorcycle which has a front wheel and a rear wheel mounted on a frame, said frame including a steering stem which has a longitudinal center axis known as the steering axis, a handlebar assembly is mounted on said steering plate and stem assembly with pivoting occurring about said longitudinal center axis, said handlebar assembly for turning of said front wheel within a horizontal steering angle which will steer said motorcycle to a leftward direction and to a rightward direction, a fork assembly connected between said steering plate and stem assembly and said front wheel, the improvement comprising:
 a power transmitting joint mounted on said frame, said power transmitting joint to receive power from a motorcycle motor, said power transmitting joint having an output shaft, said output shaft being connected to said steering plate and stem assembly, a joint housing having an internal chamber, said joint housing connected to said output shaft, an annular series of balls located within said internal chamber and drivingly connected to said joint housing, said balls connecting with said output shaft, said joint housing to be rotated by power from said motor, said power transmitting joint being mounted directly adjacent said steering stem, whereby not only will power be transmitted from said motor to said rear wheel but also said front wheel; and   a continuous chain connected between said front wheel and said power transmitting joint to cause driving rotation of said front wheel.   
     
     
         2 . The combination as defined in  claim 1  wherein:
 said frame defining a frame plane, said balls to be in alignment with said frame plane. 
 
     
     
         3 . The combination as defined in  claim 1  wherein:
 when a longitudinal center axis of said output shaft is located perpendicular to said frame plane a driving axis through said balls lies within said frame plane. 
 
     
     
         4 . The combination as defined in  claim 1  wherein:
 a torque rod mounted between said steering plate assembly and said front wheel, said torque rod and spring tensioner to maintain said continuous chain in its correct position regardless of suspension movement or power applied, said torque rod being located parallel to and in longitudinal alignment with said chain. 
 
     
     
         5 . The combination as defined in  claim 1  wherein:
 said chain and said torque rod lying within a steering plane, when said front wheel is positioned to cause said motorcycle to move in a directly forward direction said steering plane is parallel to said frame plane. 
 
     
     
         6 . The combination as defined in  claim 1  wherein:
 said internal chamber having a basically circular transverse cross-section defined by a wall surface, said internal chamber having a series of spaced apart grooves formed in said wall surface, said grooves being parallel and arcuate longitudinally, a ball of said balls to be located within each said groove with there being a separate said ball for each said groove, whereby said output shaft being movable horizontally for steering and power is continuously transmitted through said power transmitting joint regardless of the position of said steering assembly. 
 
     
     
         7 . In combination with a motorcycle which has a front wheel and a rear wheel mounted on a frame, said frame including a steering stem which has a longitudinal center axis known as the steering axis, a handlebar assembly pivotally mounted on said steering stem with pivoting occurring about said longitudinal center axis, said handlebar assembly for turning of said front wheel through a horizontal steering angle which will steer said motorcycle in a leftward direction or in a rightward direction, a fork assembly connected between said steering stem and said front wheel, the improvement comprising:
 a power transmitting joint mounted on said frame, said power transmitting joint to transmit power from a motor of said motorcycle to said front wheel, said power transmitting joint having an output shaft, said output shaft attached to said handlebar assembly, said handlebar assembly being movable horizontally through a sufficient angle to affect steering of said motorcycle, said power transmitting joint located directly adjacent said handlebar assembly.   
     
     
         8 . The combination as defined in  claim 7  wherein:
 said handlebar assembly including a steering stem which comprises an elongated member that has a longitudinal center axis defined as a steering axis, said power transmitting joint having a transverse center axis known as a driving axis, said driving axis coincides with said steering axis. 
 
     
     
         9 . The combination as defined in  claim 7  wherein:
 a continuous chain connected between said front wheel and said power transmitting joint to cause rotation of said front wheel. 
 
     
     
         10 . The combination as defined in  claim 9  wherein:
 a torque rod mounted between said handlebar assembly and said front wheel, said torque rod to maintain said continuous chain in its correct position regardless of suspension movement or power applied, said torque rod being located parallel to said chain. 
 
     
     
         11 . The combination as defined in  claim 7  wherein:
 when a longitudinal center axis of said output shaft is located perpendicular to said frame plane a driving axis defined through said power transmitting joint lies within said frame plane. 
 
     
     
         12 . The combination as defined in  claim 10  wherein:
 said chain and said torque rod lying within a steering plane, when said front wheel is positioned to cause said motorcycle to move in a directly forward direction said steering plane is parallel to said frame plane.