Patent ID: 6062926
Filing Date: 2000-05-16
Classification: B63H

Abstract:
A marine propulsion unit, comprising a housing, a vertical drive shaft journaled in said housing and operably connected to an engine, an inner propeller shaft journaled for rotation relative to said housing, a first propeller connected to said inner propeller shaft, an outer propeller shaft journaled for rotation relative to said housing and disposed concentrically outward of said inner propeller shaft, a second propeller connected to said outer propeller shaft and disposed axially forward of said first propeller, a first bevel gear operably connected to said drive shaft, first clutch means for selectively connecting said first bevel gear to said inner propeller shaft to thereby drive said inner propeller shaft and said first propeller, a second bevel gear operably connected to said drive shaft and mounted coaxially with said first bevel gear, hydraulically operated second clutch means disposed in said housing for operably connecting said second bevel gear and said outer propeller shaft, said second clutch means having an engaged position and a disengaged position, conduit means disposed in the housing for interconnecting a source of hydraulic fluid under pressure with said second clutch means, a fluid reservoir contained in said housing, and valve means disposed in said conduit means and having a first position where said hydraulic fluid is delivered to said second clutch means to effect engagement of said second clutch means to thereby drive said outer propeller shaft and said second propeller, said valve means having a second position where pressurized hydraulic fluid is dumped to said reservoir, so that pressure of the fluid delivered to the second clutch means is insufficient to engage the second clutch means.