Patent ID: 7131508

Claim:
An endless track assembly for a vehicle comprising: a) a frame including a drive sprocket; b) first and second suspension arms mounted to pivot from said frame and each supporting an axle; c) a plurality of idler wheels, wherein a first idler wheel is mounted to the axle of said first suspension arm and a second idler wheel is mounted to the axle of said second suspension arm, wherein a linkage arm is coupled between said first and second suspension arms, and wherein a resilient member is mounted to bias movement of said linkage arm, such that a pivotal movement of either of said first and second idler suspension arms is resiliently opposed or assisted by said resilient member as the other of said first and second idler wheels attempts to follow; and d) an endless track trained around said drive sprocket and said plurality of idler wheels, whereby undulations in the terrain are followed by pivotal rotation of said idler wheels to vary a longitudinal profile of said track to complement the undulations.