Mechanism for modulating clutch engagement

摘要

Clutch control comprising a first three-way valve which is automatically operated by the accelerator to effect the clutch engaging operation of a clutch control pressure differential operated motor and a second three-way valve which is automatically operated, when the clutch plates contact at a predetermined load, to terminate a relatively fast clutch engaging movement of the clutch plates. The motor is also in part controlled by a bleed valve operative to control the loading of the clutch plates as the clutch plates are moved by a clutch spring into firmer engagement with each other. The bleed valve is operative to repeatedly close and open an air bleed port in response to a signal pulse. A pulse width modulator is provided to vary the pulse width of the signal pulse.