Drive wheel suspension system for motorcycle

Claim 2

In a motorcycle having a frame, an engine with a driving sprocket, a driven wheel having an axle structure with a coaxial sprocket chain driven from the driving sprocket, and suspension mechanism for mounting the wheel on the frame of the motorcycle, the suspension mechanism including a pair of swing arms one located at each side of the wheel, pivots for mounting the forward ends of the swing arms on the frame, one pivot being located above the driving sprocket and the other being located below the driving sprocket, and linkage interconnecting the rear ends of the swing arms, said linkage including a lever at each side of the wheel, the levers being torsionally interconnected through the axle structure and one lever extended upwardly from the axle structure and being pivotally connected with one of the swing arms and the other lever extended downwardly from the axle structure and being pivotally connected with the other of the swing arms.

Claim 3

Mechanism as defined in claim 1 in which the swing arms, frame pivots and the linkage levers with their pivotal connections with the swing arms define a parallelogram linkage.

Claim 4

Mechanism as defined in claim 1 in which the axes of said frame pivots and the axis of the driving sprocket all lie substantially in the same plane.

Claim 5

Mechanism as defined in claim 1 in which the frame pivots lie substantially in a generally upright common plane and further including means for adjusting the location of at least one of said frame pivots with respect to said common plane.

Claim 6

Mechanism as defined in claim 1 and further including a shock absorber comprising a torsion bar connected at one end with one of the swing arms and connected at the other end with the frame, the torsion bar being coincident with the axis of the frame pivot for the connected swing arm.

Claim 7

Mechanism as defined in claim 5 in which the torsion bar is mounted on the frame by pivot bearing means providing the frame pivot for the connected swing arm.

Claim 8

Mechanism as defined in claim 5 and further including torsionally adjustable means for connecting the torsion bar to the frame with freedom for torsional adjustment thereof.

Claim 9

In a motorcycle having a frame, an engine with a driving sprocket, a driven wheel having an axle structure with a coaxial sprocket chain driven from the driving sprocket, suspension mechanism for mounting the wheel on the frame of the motorcycle, the suspension mechanism including a pair of swing arms one located at each side of the wheel, and one located in a higher position than the other, pivots for mounting the forward ends of the swing arms on the frame, one pivot being located above the axis of the driving sprocket and the other being located below the axis of the driving sprocket, and linkage interconnecting the rear ends of the swing arms through the axle structure of the wheel, said linkage including a lever at each side of the wheel, the levers being torsionally interconnected through the axle structure and one lever extended upwardly from the axle structure and being pivotally connected with one of the swing arms at a distance corresponding to the distance of the frame pivot for that arm above the axis of the driving sprocket and the other lever extended downwardly from the axle structure and being connected with the other of the swing arms at a distance corresponding to the distance of the frame pivot for that arm below the axis of the driving sprocket.

Claim 10

In a motorcycle having a frame, an engine with a driving sprocket, a driven wheel having an axle structure with a coaxial sprocket chain driven from the driving sprocket, suspension mechanism for mounting the wheel on the frame of the motorcycle, the suspension mechanism including a pair of swing arms one located at each side of the wheel, and one located in a higher position than the other, pivots for mounting the forward ends of the swing arms on the frame, one pivot being located above the axis of the driving sprocket and the other being located below the axis of the driving sprocket, and linkage interconnecting the rear ends of the swing arms through the axle structure of the wheel, said linkage including a lever at each side of the wheel, the levers being torsionally interconnected through the axle structure and one lever extended upwardly from the axle structure and being pivotally connected with one of the swing arms at a distance corresponding to the distance of the frame pivot for that arm above the axis of the driving sprocket and the other lever extended downwardly from the axle structure and being connected with the other of the swing arms at a distance corresponding to the distance of the frame pivot for that arm below the axis of the driving sprocket.

Claim 11

Mechanism as defined in claim 8 and further including means for adjusting the distance between the axis of the frame pivot and the axis of the lever pivot for at least one of the swing arms.

Claim 12

In a motorcycle having a frame, an engine with a drive sprocket, a driven wheel having an axle structure with a coaxial sprocket chain driven from the driving sprocket, suspension mechanism for mounting the wheel on the frame of the motorcycle, the suspension mechanism including linkage having pivots on the frame and providing for swing motion of the wheel and driven sprocket substantially about the axis of the driving sprocket, and adjustable means associated with one of the linkage pivots on the frame and including means for fixing the position of the linkage in different positions with respect to the axis of said one linkage pivot in a direction toward and away from the wheel.

Claim 13

In a motorcycle having a frame, an engine with a drive sprocket, a driven wheel having an axle structure with a coaxial sprocket chain driven from the driving sprocket, suspension mechanism for mounting the wheel on the frame of the motorcycle, the suspension mechanism including linkage having pivots on the frame and providing for swing motion of the wheel and driven sprocket substantially about the axis of the driving sprocket, and adjustable means associated with one of the linkage pivots on the frame and including means for fixing the position of the linkage in different positions with respect to the axis of said one linkage pivot in a direction toward and away from the wheel.

Claim 14

In a motorcycle having a frame, an engine with a driving sprocket, a driven wheel having an axle structure with a coaxial sprocket chain driven from the driving sprocket, suspension mechanism for mounting the wheel on the frame of the motorcycle, the suspension mechanism including linkage comprising a plurality of levers having pivots on the frame in positions offset from the axis of the driving sprocket, but providing for swing motion of the wheel and driven sprocket substantially about the axis of the driving sprocket, and a torsion bar connected with the linkage coaxially of a linkage pivot offset from the axis of the driving sprocket and providing shock absorption with respect to swing motion of the wheel.

Claim 15

In a motorcycle having a frame, an engine with a driving sprocket, a driven wheel having an axle structure with a coaxial sprocket chain driven from the driving sprocket, suspension mechanism for mounting the wheel on the frame of the motorcycle, the suspension mechanism including linkage comprising a plurality of levers having pivots on the frame in positions offset from the axis of the driving sprocket, but providing for swing motion of the wheel and driven sprocket substantially about the axis of the driving sprocket, and a torsion bar connected with the linkage coaxially of a linkage pivot offset from the axis of the driving sprocket and providing shock absorption with respect to swing motion of the wheel.

Claim 16

In a motorcycle having a frame, an engine with a driving sprocket, a driven wheel having an axle structure with a coaxial sprocket chain driven from the driving sprocket, suspension mechanism for mounting the wheel on the frame of the motorcycle, the suspension mechanism including linkage including two linkage elements having pivots on the frame above and below the driving sprocket and providing for swing motion of the wheel, adjustable means for fixing the position of a linkage element in different positions with respect to the axis of its pivot on the frame in a direction toward and away from the wheel, and a torsion bar associated with the linkage coaxially of the pivot for the other linkage element and providing shock absorption with respect to swing motion of the wheel.

Claim 17

In a motorcycle having a frame, an engine with a driving sprocket, a driven wheel having an axle structure with a coaxial sprocket chain driven from the driving sprocket, suspension mechanism for mounting the wheel on the frame of the motorcycle, the suspension mechanism including linkage including two linkage elements having pivots on the frame above and below the driving sprocket and providing for swing motion of the wheel, adjustable means for fixing the position of a linkage element in different positions with respect to the axis of its pivot on the frame in a direction toward and away from the wheel, and a torsion bar associated with the linkage coaxially of the pivot for the other linkage element and providing shock absorption with respect to swing motion of the wheel.

Claim 18

In a motorcycle having a frame, an engine with a driving sprocket, a driven wheel having an axle structure with a coaxial sprocket and with a driving chain interconnecting said sprockets, suspension mechanism for mounting the wheel for swing motion substantially about the axis of the driving sprocket the suspension mechanism including a swing arm and a lever with a mounting pivot positioned in offset relation to the axis of the sprocket in a generally upright plane containing the axis of the sprocket, and a chain slack takeup device comprising adjustable means for fixing the position of said arm in different positions with respect to the axis of said mounting pivot in a direction toward and away from the wheel.

Claim 19

In a motorcycle having a frame, an engine with a driving sprocket, a driven wheel having an axle structure with a coaxial sprocket and with a driving chain interconnecting said sprockets, suspension mechanism for mounting the wheel for swing motion substantially about the axis of the driving sprocket the suspension mechanism including a swing arm and a lever with a mounting pivot positioned in offset relation to the axis of the sprocket in a generally upright plane containing the axis of the sprocket, and a chain slack takeup device comprising adjustable means for fixing the position of said arm in different positions with respect to the axis of said mounting pivot in a direction toward and away from the wheel.