Carbon to carbon friction clutch

Claim 1

A carbon to carbon friction clutch for attachment to an engine flywheel comprised in combination of: a. a clutch cover; b. a diaphragm spring bolted to said clutch cover; c. drilled spacer blocks radially distributed between the clutch cover and the flywheel; d. bolts passing through said spacer blocks and holding the clutch cover at a fixed axial distance from the engine flywheel; e. a pressure disk which is moveable axially along said spacer blocks, rotates with the cover and flywheel and contacts the diaphragm spring; f. a first set of carbon disks which are moveable axially along said spacer blocks, rotate with the clutch cover and flywheel and are alternately spaced between and in selectively engageable contact with a second set of carbon disks, each of the second set being provided with a central aperture and a plurality of evenly spaced slots extending radially from the central aperture; g. central holes in the first set of carbon disks; h. a relatively flat, circular, metallic hub having oppositely facing end surfaces with a splined, circular opening at its center and formed with radial fingers on said end surfaces, the fingers fitting into the slots in the second set of carbon disks, the hub being of a diameter to be contained without touching within the central holes of the first set of carbon disks; i. a splined shaft entering the center of the clutch and engaging said hub at its spline; j. a throwout bushing slidable along the splined shaft to contact said diaphragm spring; whereby the diaphragm spring, acting upon said pressure disk, forces the first set of carbon disks into a frictional holding of the second set of carbon disks, which by virtue of their slots into which the fingers of said hub are engaged, transmit the turning of the flywheel to the splined shaft and axial movement of said throwout bushing against the diaphragm spring releases pressure between the first and second sets of carbon disks causing axial movement of the disks, slippage between the disks and the cessation of rotation of the hub and the shaft to which it is splined and whereby said metallic hub isolates the second set of carbon plates from shear forces which would otherwise be encountered if said second set of carbon plates were provided with splines and directly engaged to the splined shaft.