Abstract: A gaseous fuel injection system for internal combustion engines features a "variable-pressure-controller" which translates a varying negative pressure, sensed in the engine's air intake system by means responsive to the rate of flow of the intake air, into a proportionately varying amount of gaseous fuel at a positive pressure. That fuel is then injected into the engine's air intake system upstream or downstream of the throttle valve through flow restrictor means which cooperate with the variable-pressure-controller to provide an amount of fuel proportionate to the rate of air flow through the engine's air intake system. The invention is entirely mechanical-pneumatic in operation and readily adapted to a wide variety of liquid fueled engines, carbureted as well as fuel injected, or to one for gaseous fuel only.

Abstract: An attachment for operating an internal combustion engine on either gaseous or liquid fuel incorporates a modified air cleaner assembly having a cover and an annular adapter between which is sandwiched a typical annular filter element, the adapter fitting over the engine air intake. A diaphragm movably mounts a circular diaphragm plate to the cover to form a chamber therewith on one side of the diaphragm plate and an annular venturi between the other side of the diaphragm plate and the adapter. In one version gaseous fuel is admitted into the chamber through an inlet fitting secured to the cover and thence through ports in the diaphragm plate into the venturi. In another version the gaseous fuel is admitted through an inlet fitting secured to the adapter and thence into the venturi through ports in the adapter, a hose connecting the inlet fitting and the chamber.

Abstract: A slow-run system for gaseous fueled internal combustion engines, including gaseous fuel conversions of liquid fuel engines for alternate operation on either fuel, employs a valve having an inlet receiving gaseous fuel from between the primary regulator and zero pressure governor and an outlet emptying into the air cleaner assembly upstream of the liquid fuel carburetor or equivalent means. The valve is actuated through a connection into the engine air intake manifold or similar passage below the throttle such that the valve opens to supply gaseous fuel to the air cleaner assembly during slow-run when manifold vacuum is high and remains open throughout substantially all of the engine's operating range.

Abstract: A demand type governor for gaseous fuel internal combustion engines, various kinds of breathing and heating apparatus and similar applications features a diaphragm controlled inlet valve having two different rates of opening movement for a given rate of movement of the diaphragm producing a relatively small amount of valve movement in relation to diaphragm movement for instances of lower demands and a relatively larger amount of valve movement in relation to diaphragm movement for instances of higher demands, all by means of a lever-fulcrum arrangement having a higher mechanical advantage in the first instances and a lower mechanical advantage in the second instances. Other features of the governor help assure its uniform, relatively frictionless operation, and its ease and economy of manufacture.