Abstract: A differential transmission mechanism using an output differential for a constant speed drive has desirable characteristics including full utilization of the torque capabilities of the hydraulic trim device associated with the output differential; however, there is a limitation on the utilization of the speed capability of the hydraulic components of the trim device at the low end of the input speed range.The disclosed differential transmission mechanism utilizing an output differential has a hydraulic trim device with a first hydraulic displacement unit having a normally fixed, approximately maximum displacement connected to an element of the output differential and a second hydraulic displacement unit which is of variable displacement connected to a variable speed input shaft. Additional components of the output differential are connected to the input shaft and to an output shaft connectable to a load.

Abstract: For gear boxes, constant speed drives and the like having an airtight housing, a self-pressurization system includes a source of liquid, a pump having a discharge port connected to the housing, a check valve in a conduit extending between atmosphere and the pump intake port, and a valve responsive to the pressure differential between the housing and atmosphere and connected between the source of liquid and the pump intake port to deliver large amounts of liquid to the pump when the pressure differential is high and to deliver air and minimal lubricating amounts of liquid when the pressure differential is low.

Abstract: An emergency hydraulic power system for aircraft which becomes operable upon aircraft engine failure includes a hot gas turbine for driving a hydraulic pump, a decomposition chamber to provide hot gas for driving the turbine, a normally unpressurized fuel storage tank, and a fuel pump for delivering fuel from the tank to the decomposition chamber. A start system includes a start fuel bottle having a cell filled with fuel and provided with a movable wall, and a cylinder of gas under high pressure which is regulated to put intermediate pressure on the movable wall and expel fuel from the cell, and also to put low pressure on the fuel tank, after a start valve is opened. Both the fuel tank and the start fuel cell communicate with an inlet conduit which goes to the fuel pump inlet, and a valve is provided to prevent start fuel from going into the fuel tank; and there is also means normally blocking communication from the start bottle and the tank to the pump inlet.