Snowmobile adjustable suspension

Claim 2

A snowmobile comprising: a chassis having a seat for holding a rider; ski means mounted at the front portion of the chassis for supporting the front portion thereof on the ground; a track drive assembly mounted at the rear portion of the chassis, including a track extending in a loop, a sprocket wheel at the front of the track loop, and a tension wheel at the rear of the track loop which holds the track under tension; an engine mounted on the chassis and coupled to the sprocket wheel to rotate it and thereby drive the track to move the Chassis along the ground; a pair of laterally spaced rails disposed within the track loop and bearing against the track, said rails attached to the tension wheels so that the rails can keep the tension wheels from shifting forwardly; a suspension assembly for mounting the chassis on the rails and for preventing the rails from shifting forwardly, said suspension assembly having suspension arm means with lower portions connected to the rails and upper portions, and spring means urging the upper portions of the arm means upwardly with respect to the rails; first guide means having a primarily vertically extending guideway which extends continuously between the lowest and highest location therealong; second guide means engaged with said guideway and moveable continuously therealong so that relative movement is vertical, one of the guide means attached to the chassis and the other attached to the upper end of the suspension arm means so that the upper end of the suspension arms means is confined to primarily vertical movement relative to the chassis; and an adjustor coupled to the two guide means for holding the second guide means at selected positions along the vertical guideway of the first guide means, whereby to permit raising and lowering of the chassis while preventing uncontrolled forward shifting of the rails to thereby keep the track under tension.

Claim 3

The snowmobile described in claim 1 wherein: said first guide means includes a pair of plates on laterally opposite sides of the chassis, each plate having a primarily vertically-extending slot therein; said second guide means includes a pair of follower members extending through the slots of the plates and coupled to the upper end of the suspension arm means; and said adjustor includes a screw adjust member and nut adjust member on each side of the chassis, one of the adjust members coupled to the plate to be supported by it and the other coupled to the follower member and threadably engaged with the other adjust member.

Claim 4

In a snowmobile which has a chassis supported along its rear portion by a spring suspension which includes an arm assembly that has a lower end supported on a track, the improvement comprising: a plate on either side of the chassis, each plate having a vertically-extending slot; a pair of follower members mounted on the arm assembly, each follower member extending through the slot of a different one of said plates; and a pair of adjustors, each located at a different side of the chassis, each adjustor having a pair of threadably engaged members respectively engaged with the plate and follower at the corresponding side of the chassis to permit a continual adjustment of the height of the chassis.

Claim 5

In a snowmobile which has a chassis supported along its rear portion by a spring suspension which includes an arm assembly that has a lower end supported on a track, the improvement comprising: a plate on either side of the chassis, each plate having a vertically-extending slot; a pair of follower members mounted on the arm assembly, each follower member extending through the slot of a different one of said plates; and a pair of adjustors, each located at a different side of the chassis, each adjustor having a pair of threadably engaged members respectively engaged with the plate and follower at the corresponding side of the chassis to permit a continual adjustment of the height of the chassis.

Claim 6

A snowmobile comprising: a chassis having a seat for holding a rider; ski means mounted at the front portion of the chassis for supporting the front portion thereof on the ground; a track drive assembly mounted at the rear portion of the chassis, including a track extending in a loop, a sprocket wheel at the front of the track loop, and a tension wheel at the rear of the track loop which holds the track under tension; an engine mounted on the chassis and coupled to the sprocket wheel to rotate it and thereby drive the track to move the chassis along the ground; a pair of laterally spaced rails disposed within the track loop and bearing against the track, said rails attached to the tension wheels so that the rails can keep the tension wheels from shifting forwardly; a suspension assembly for mounting the chassis on the rails and for preventing the rails from shifting forwardly, said suspension assembly having suspension arm means with lower portions connected to the rails and upper portions, and spring means urging the upper portions of the arm means upwardly with respect to the rails; first guide means having a primarily vertically extending guideway; second guide means engaged with said guideway and Moveable therealong so that relative movement is vertical, one of the guide means attached to the chassis and the other attached to the upper end of the suspension arm means so that the upper end of the suspension arms means is confined to primarily vertical movement relative to the chassis; an adjustor coupled to the two guide means for holding the second guide means at selected positions along the vertical guideway of the first guide means, whereby to permit raising and and lowering of the chassis while preventing uncontrolled forward shifting of the rails to thereby keep the track under tension; and a manual control member mounted on said chassis and easily accessible and operable by a rider on said seat while the snowmobile is moving along the ground, said control member coupled to the adjustor to operate it to raise and lower the second guide means.

Claim 7

A snowmobile comprising: a chassis having a seat for holding a rider; ski means mounted at the front portion of the chassis for supporting the front portion thereof on the ground; a track drive assembly mounted at the rear portion of the chassis, including a track extending in a loop, a sprocket wheel at the front of the track loop, and a tension wheel at the rear of the track loop which holds the track under tension; an engine mounted on the chassis and coupled to the sprocket wheel to rotate it and thereby drive the track to move the chassis along the ground; a pair of laterally spaced rails disposed within the track loop and bearing against the track, said rails attached to the tension wheels so that the rails can keep the tension wheels from shifting forwardly; a suspension assembly for mounting the chassis on the rails and for preventing the rails from shifting forwardly, said suspension assembly having suspension arm means with lower portions connected to the rails and upper portions, and spring means urging the upper portions of the arm means upwardly with respect to the rails; first guide means having a primarily vertically extending guideway; second guide means engaged with said guideway and Moveable therealong so that relative movement is vertical, one of the guide means attached to the chassis and the other attached to the upper end of the suspension arm means so that the upper end of the suspension arms means is confined to primarily vertical movement relative to the chassis; an adjustor coupled to the two guide means for holding the second guide means at selected positions along the vertical guideway of the first guide means, whereby to permit raising and and lowering of the chassis while preventing uncontrolled forward shifting of the rails to thereby keep the track under tension; and a manual control member mounted on said chassis and easily accessible and operable by a rider on said seat while the snowmobile is moving along the ground, said control member coupled to the adjustor to operate it to raise and lower the second guide means.