Abstract: A centrifugal clutch for motorcycles having a cam-actuating mechanism to force a series of clutch plates into clutching engagement at a predetermined speed, a pressure limiting spring assembly limits the axial force transmitted to the clutch members at higher speeds so that the torque transmission characteristics of the clutch are similar to a manual clutch, and a manual override is capable of maintaining the clutch plates in the disengaged position at lower speeds as well as shifting the clutch members out of clutching engagement at higher speeds with relatively low exertion of manual or hand pressure.

Abstract: A clutch having a plurality of cam members between a cover and pressure plate to move outwardly under centrifugal force and cause the pressure plate to move axially to force a plurality of clutch plates into clutching engagement, a manual override mechanism to lock out the pressure plate to maintain the clutch plates in a disengaged position, and pressure limiting springs prevent shock loads from being imparted to the clutch plates when the plates are advanced into clutching engagement with one another. The clutch housing includes a cover which can be mounted either flush or inset in circumferentially spaced walls of the housing and held in place by a retaining ring inserted into slots in the side walls and is adaptable for use with any type of clutch with or without the manual override mechanism and pressure limiting springs.

Abstract: A centrifugal clutch for motorcycles employs a cam-actuating mechanism having multiple rows of centrifugal force-responsive cam members of a selected density and size to force a series of clutch plates into clutching engagement over the shortest possible distance and least possible speed of rotation while assuring ease of positive engagement of the clutch members in response slight increases in speed of rotation. The cam-actuating mechanism can be employed with a manual override mechanism to manually control locking and release of the clutch members as well as utilizing a torque limiter to absorb shock loads without unduly increasing the size of the clutch so that it will readily fit into the space occupied by existing or standard clutch mechanisms.