Patent ID: 7717250

Claim:
A centrifugal clutch comprising: a driver adapted to engage an input shaft, the driver having a rotational axis and a plurality of radial teeth each extending outwardly; a drum coaxial with the driver and adapted to engage a driven component; a plurality of shoes located between the driver and the drum and arranged about the axis, the shoes each being radially movable along a corresponding radial axis between an outward position in which the shoes contact a surface of the drum and an inward position in which the shoes are spaced apart from the drum, each shoe comprising; a drum contacting member which is adapted to contact a portion of the drum, the drum contacting member having a leading edge extending circumferentially in one direction from the radial axis and a trailing edge extending circumferentially in an opposite direction from the radial axis, the drum contacting member further having a mass adjustment mechanism for tuning the engagement characteristics of the clutch by adjusting a center of mass of the shoe with respect to the leading and trailing edges; and a support having one end attached to the drum contacting member and the other end extending radially inward and having a recess engaged by a corresponding one or more of the radial teeth such that when the shoe moves to the outward position the shoe rotates slightly with respect to the radial axis in response to the center of mass of the shoe, the support including a pair of spring attachment mounts formed on the radially inward end thereof; wherein when the center of mass is toward the leading edge of the shoe, the leading edge contacts the drum before the trailing edge, causing the clutch to exhibit more aggressive engagement with the drum and causing an increase in the torque that can be carried by the clutch before slipping; and wherein when the center of mass is toward the trailing edge of the shoe, the trailing edge contacts the drum before the leading edge, causing the clutch to exhibit less aggressive engagement with the drum and causing a decrease in the torque that can be carried by the clutch before slipping; and a plurality of springs, each spring engaging two adjacent shoes by attaching to one spring attachment mount on each shoe, the spring biasing the shoes toward one another.