Patent ID: 7819232

Claim:
A clutch comprising: a lever mechanism portion and a clutch mechanism portion operatively connected to each other; wherein the lever mechanism portion includes a lever including a first contact portion; and the clutch mechanism portion includes a pressing member, the clutch mechanism portion further including a first plate and a second plate positioned adjacent to the first plate, the pressing member being arranged to move in a first direction toward the first plate such that the first and second plates are brought into contact with each other and in a second direction away from the first plate such that the first and second plates separate from each other; the clutch mechanism portion includes a biasing member arranged to bias the pressing member in the first direction; the clutch mechanism portion includes a relay member, the relay member including a second contact portion, the second contact portion of the relay member being arranged to contact with the first contact portion of the lever at a contact location that varies relative to a pivot axis when the lever is pivoted, the relay member being arranged to transmit movement of the lever of the lever mechanism portion to the pressing member of the clutch mechanism portion; the lever of the lever mechanism portion is arranged to move between a pivot start position and a pivot finish position such that, when the lever is moved from the pivot start position, the second contact portion of the relay member is in contact with the first contact portion of the lever and the relay member translates the movement of the lever to the pressing member and the pressing member moves in the second direction; as the contact location varies between the first contact portion of the lever and the second contact portion of the relay member, a lever ratio of the lever changes from a larger lever ratio at the pivot start position to a smaller lever ratio at the pivot finish position; the biasing member is arranged to apply a decreasing force from the pivot start position to the pivot finish position of the lever; and the contact location at the pivot start position of the lever is on one side of a plane that extends through the pivot axis and that is perpendicular to an axis of the relay member along which the relay member transmits movement of the lever, and the contact location at the pivot finish position of the lever is on an opposite side of the plane that extends through the pivot axis and that is perpendicular to the axis of the relay member.