Normally open clutch assembly device

#This invention relates to a normally open clutch assembly, and specifically to a device for maintaining alignment of a normally open clutch during assembly.

#Typically, a normally open clutch assembly includes a rotating input member such as a flywheel, that engages one or more friction disks. The frictions disks are forced against the flywheel by one or more pressure plates. An output shaft is driven by rotation of the friction disks. A plurality of centrifugal weights are pivotally mounted to rotate radially outward in response to rotation of the clutch assembly. As the rotational speed of the clutch assembly increases rollers on the centrifugal weights are forced up a ramped surface to force engagement of the pressure plates with the friction disks and transmit rotational movement to the output shaft.

#Assembly of a clutch assembly requires proper alignment between the friction disks and the flywheel. Normally closed clutch assemblies use the biasing force normally clamping the pressure plates against the friction disks to maintain proper alignment during assembly. Disadvantageously, a normally open clutch assembly does not clamp the friction disks unless the centrifugal weights are driven outward by rotation of the clutch assembly. Therefore the friction disks are not held in a desired aligned position during assembly.

#The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows:

#FIG. 1 is a cross-sectional view of a clutch assembly including a positioning pin according to this invention;

#FIG. 2 is an enlarged cross-sectional view of the positioning pin of this invention in an assembly position;

#Referring to FIG. 1, a clutch assembly 10 includes a clutch cover 12 attached to a flywheel 14. A plurality of centrifugal weights 16 are pivotally mounted within the clutch cover 12 and rotate radially outward in response to rotation of the clutch cover 12. Each centrifugal weight 16 is biased toward a central axis 18 by a biasing spring 20. Rollers 21 are mounted to each centrifugal weight 16 and ride along surfaces of a ramp plate 22 and an inner surface of the clutch cover 12. The ramp plate 22 includes a ramped surface 24 on which the roller 21 moves to cause axial movement of the ramp plate 22. Axial movement of the ramp plate 22 is transmitted through a clamp spring 26 to pressure plates 28. Friction disks 30 are disposed between the pressure plates 28 such that axial movements of the pressure plates 28 clamp the friction disks 30 therebetween.

#The biasing member 20 biases the centrifugal weight 16 toward the axis 18 such that the pressure plates 28 are not engaged to the friction disks 30. An alignment tool (not shown) such as a splined shaft is used to align the position of the friction disks 30 relative to the clutch cover 12 and flywheel 14. However, once the alignment tool is removed and prior to an output shaft 32 being installed into the clutch assembly 10, the friction plates 30 are not restrained and are free to move out of the set alignment.

#The clutch assembly 10 of this invention includes a plurality of pins 34 holding a corresponding plurality of centrifugal weights 16 in a position causing axial movement and thereby engagement between the pressure plates 28 and the friction disks 30. Each of the pins 34 hold a corresponding centrifugal weight 16 in a position causing application of a clamping force on the friction disks 30 that holds the friction disks 30 in the desired aligned position.