Abstract: A refueling cart, for refueling large aircraft at a major airport having pressurized fuel hydrants at loading/unloading aprons, includes auxiliary facilities on the refueling cart that are usually powered by compressed air that is obtained from compressed-air bottles carried on the cart. In order to avoid the labor and annoyance of checking and refilling the bottles of compressed air, a small air compressor is carried on the refueling cart and is powered by a hydraulic motor that is in turn powered by the flowing pressurized fuel. A variable-flow valve is placed in the path of the fuel flowing from a hydrant to the airplane. The pressure generated across the variable-flow valve by the flowing fuel pushes some of the fuel in a path that bypasses the variable-flow valve. That bypass path includes the hydraulic motor, and the bypassing fuel at the pressure difference generated by the variable-flow valve drives the fluid motor. The fluid motor, in turn, drives the air compressor.

Abstract: A refueling cart, for refueling large aircraft at a major airport having pressurized fuel hydrants at loading/unloading aprons, includes auxiliary facilities on the refueling cart that are usually powered by compressed air that is obtained from compressed-air bottles carried on the cart. To avoid the labor and annoyance of checking and refilling the bottles of compressed air, a small air compressor is carried on the refueling cart and is powered by a fluid motor that is in turn powered by the flowing pressurized fuel. A variable orifice is placed in the path of the fuel flowing from a hydrant to the airplane. The pressure generated across the variable orifice by the flowing fuel pushes a small amount of fuel in a path that bypasses the orifice. That bypass path includes the fluid motor, and the bypassing fuel at the pressure difference generated by the orifice drives the fluid motor. The flow of fuel to the airplane is not constant but varies as the planes tank(s) are filled.