Abstract: A reversing marine drive utilizing a gas generator prime mover provided with first and second counter-rotating power turbines. The first turbine is connectable by a differential gear set and a pinion and reduction gear assembly to the ship's shaft to drive the shaft and the screw thereon in the forward thrust direction. The second turbine is connectable by the differential gear set and the pinion and reduction gear assembly to the ship's shaft to drive it and the screw thereon in the reverse thrust direction. A brake assembly is provided in association with each of the first and second power turbines so that when one of the power turbines is driving the screw, the other power turbine is stopped. A master computer may be provided to control the reversing marine drive.

Abstract: A grinding wheel mounting apparatus and method of demounting is characterized by a shaft having a tapered end portion, a wheel adaptor including a tapered axial bore for mounting on the tapered end portion of the shaft. The hole and tapered end portion of the shaft have correspondingly tapered surfaces frictionally engaging over an area of contact to couple the adaptor to the shaft for common rotation. A fluid passage means is provided for directing pressurized fluid to a point within the confines of the area of contact so that the pressure of such fluid may exert both radial and axial forces on the adaptor to effect its release from the shaft. A removal fitting is also disclosed which may be threaded on to the shaft. The removal fitting has an O-ring seal to provide a fluid tight seal with the shaft and a grease fitting. An internal passage in the removal fitting enables grease under pressure to flow to the fluid passage means.