Patent ID: 6443286
Filing Date: 2002-09-03
Classification: B63H,F16D

Abstract:
A modulatable power transmission clutch including interleaved clutch plates, said clutch having a central power transmitting shaft extending axially through said clutch mounted thereon, said clutch including a fluid operated movable piston for effecting clutch operation by compression of said plates, said piston having smaller and larger piston areas thereon, the smaller piston area being adapted to have fluid flow directed thereto at a variable fluid pressure whereby said clutch is modulatable, the larger piston area being adapted to have fluid flow directed thereto to effect maximum and unmodulatable engagement of said clutch;and a spring loaded normally closed valve for controlling fluid flow to said larger piston area in response to fluid pressure above a predetermined amount at said smaller piston area, said valve being mounted in said shaft and being normally closed whereby pressure fluid is directed to said smaller piston area at a variable fluid pressure whereby said clutch is modulatable, and when said valve is open by said fluid pressure over a predetermined amount permits fluid flow to said larger piston area to effect maximum and unmodulatable engagement of said clutch for full clutch capacity.