Fuel system

Claim 2

A fuel system for an internal combustion engine comprising: a. at least one fuel reservoir; b. a mixing duct, having a mixing zone in which, during operation of the engine, fuel is mixed with an oxidant (such as air) to form a combustible mixture which passes through the duct to the engine; c. a canister, oriented in a vertical position and containing a body of material capable of reversibly absorbing fuel volatilized from the reservoir, said canister being open at its top at all times to the oxidant at its full static pressure; d. a first conduit having one end connected to the vapor area of the reservoir and its other end comprises a tube having a plurality of apertures and is imbedded in the uppermost layer of the body of material, whereby heavier-than-air fuel vapors entering the canister will descend downwardly through and become adsorbed within said body of material; e. a second conduit having its one end connected to the bottom of the container and its other end connected to the duct at a region upstream of the mixing zone; whereby, when the engine is not in operation, any fuel volatilized from the reservoir passes through the first conduit to the container for adsorption in the body of material, and whereby when the engine is opErating, oxidant at its full static pressure is drawn downwardly through the body of material from the open top of the container to desorb any fuel adsorbed in the body of material and the mixture of air and desorbed fuel is introduced, through the second conduit, to the duct upstream of the mixing zone, the rate of desorption of the fuel adsorbed in the body of material being proportional to the depression of pressure in the duct in the region upstream of the mixing zone.

Claim 3

The system according to claim 1 in which the second conduit has a part which extends upwardly substantially to the level of the uppermost layer of the body of material.

Claim 4

The system according to claim 1 in which the first conduit includes an expansion tank which is disposed in said first conduit intermediate said fuel reservoir and said canister.

Claim 5

The system according to claim 1 in which the fuel reservoir comprises a fuel storage tank containing a filling orifice and a cap capable of sealing the orifice, said tank being sealed and not in communication with the atmosphere during such time that the cap seals the orifice.

Claim 6

The system according to claim 1 in which the engine contains an air filter or air cleaner and the second conduit is connected at its other end to the air filter or air cleaner.

Claim 7

The system according to claim 1 in which there are two fuel reservoirs, one of said reservoirs being the fuel storage tank and the other reservoir being the bowl of a carburetor, and there are two first conduits, one of which has its one end connected to the vapor area of the fuel storage tank and its other end imbedded in the uppermost layer of said body of material, and the other first conduit has its one end connected to the vapor area of the carburetor bowl and its other end imbedded in the uppermost layer of said body.

Claim 8

The system according to claim 6 wherein: a. the engine contains a throttle valve disposed in the duct downstream of the mixing zone; b. the other first conduit includes a pressure balance valve disposed intermediate between the vapor area of the carburetor bowl and the body of material; c. the system contains a third conduit which is connected at its one end to the pressure balance valve and at its other end to the duct in the region of the mixing zone; d. the system contains a fourth conduit which is connected at its one end to the pressure balance valve and at its other end to the duct downstream of the mixing zone, said pressure balance valve having a member which is movable between a first position in which communication is permitted, through the pressure balance valve, between the vapor area of the carburetor bowl and the body of material, and communication is prevented between said other first conduit and said third conduit, and a second position in which communication is permitted, through the pressure balance valve, between the vapor area of the carburetor bowl and the region of the mixing zone of the duct, and communication is prevented between the vapor area of the carburetor bowl and the body of material, said pressure balance valve also containing spring means which bias the valve member to said first position whereby volatilized fuel from the vapor area of the carburetor bowl is introduced through said other first conduit into the body of material, the valve member being moved to said second position against said bias by a predetermined vacuum in said fourth conduit whereby volatilized fuel from the vapor area of the carburetor bowl is introduced through said third conduit to the mixing zone of the duct.