Patent ID: 7276004

Claim:
A sliding centrifugal drive weight for use in an automatic continuous variable transmission which has a rotary shaft with a drive pulley including a movable drive pulley half, a ramp plate and a stationary drive pulley half, a driven pulley, an endless V-belt having one end rotatably fitted around a groove confined by the drive pulley and the other end rotatably fitted around a groove confined by the driven pulley, and a plurality of centrifugal drive weights mounted between the ramp plate and ramps of the movable drive pulley half ,whereby in a rotational movement of the drive pulley, the centrifugal drive weights are adapted to move radially outward along the ramp of the movable drive pulley half upon a centrifugal force acting thereon while the movable drive pulley half moves axially toward the stationary drive pulley half so as to change sizes of the grooves of the drive pulley and the driven pulley and an effective diameter of the V-belt in each of the drive pulley and the driven pulley is changed, thereby effecting a gearshifting; said sliding centrifugal drive weight comprising a center point; an inner core weight formed of metal; and an outer friction shell formed of durable self-lubricated plastics having an outer surface with an upper inclined face having a distance d 2 from said center point, measured in a direction normal to said inclined face, and being in sliding contact with an inner surface of the ramp plate, a bottom surface having a distance d 4 from said center point and being in sliding contact with the ramp of the movable drive pulley half, a left face, being the nearest surface of said sliding centrifugal drive weight to the axis of rotation of the rotary shaft, having a distance d 1 from said center point, measured in a direction normal to said rotary shaft, and being urged against a left side inner wall of the movable drive pulley half when said sliding centrifugal drive weight is at its lowest position in the movable drive pulley half, and a right wear resistant face having a distance d 3 from said center point, measured in a direction normal to said rotary shaft, and approaching a right side inner wall of the movable drive pulley half when said sliding centrifugal drive weight is at its highest position in the movable drive pulley half; wherein d 2 >d 3 such that said sliding centrifugal drive weight is adapted to compensate for wear automatically and to adjust by itself to move further radially outward to obtain a higher maximum vehicle speed.