Abstract: A hydraulic speed control controls the fuel rate to an internal combustion engine. A fluid pump pumping in proportion to engine speed provides fluid to a piston in a cylinder. The position of the piston in the cylinder is attaind by a balance between the incoming fluid from the pump and the fluid flow from two outlets. Resistance to flow from one of the outlets is controlled by an accelerator valve. The position of the piston is coupled to the fuel flow controller for the engine. An economizer retards the motion of the piston toward high fuel flow rates and aids the motion of the piston toward low fuel flow rates.

Abstract: Pump bodies are formed by cutting sections from hollow drawn or extruded stock.