Patent ID: 7802645

Claim:
A suspension assembly for a vehicle having a chassis and an endless drive track, the suspension assembly comprising: a suspension arm having a first end and a second end, the first end of the suspension arm being pivotally connectable to the chassis; a slide frame assembly pivotally connected to the second end of the suspension arm; at least one shock absorber assembly pivotally connected to the slide frame assembly, the at least one shock absorber assembly biasing the slide frame assembly away from the chassis; a rail extension assembly comprising at least one extension arm, the at least one extension arm having a front end, the front end of the at least one extension arm being pivotably connected to a rear portion of the slide frame assembly about a first axis, the rail extension assembly being pivotable between a raised position and a lowered position with respect to the slide frame assembly about the first axis; at least one rear idler wheel rotatably connected to a rear portion of the rail extension assembly for guiding the endless drive track; at least one spring biasing the rail extension assembly toward the lowered position by exerting thereon a biasing force; a movable member movable between a first position and a second position to adjust the magnitude of the biasing force; at least one blocking cam mounted to one of the slide frame assembly and the rail extension assembly, the at least one blocking cam being movable between a first position and a second position to prevent the rail extension assembly from pivoting from the lowered position to the raised position independently of a magnitude of the biasing force; and at least one stopper mounted to the other of the slide frame assembly and the rail extension assembly; wherein when the rail extension assembly is in the lowered position, the at least one blocking cam is movable between: the first position, where the at least one blocking cam prevents the rail extension assembly from pivoting to the raised position; and the second position, where the at least one blocking cam does not prevent the rail extension assembly from pivoting to the raised position; wherein when the at least one blocking cam is in the second position and the rail extension assembly is in the raised position, the at least one blocking cam abuts against the at least one stopper.