Dual tank fuel system

Claim 2

A vehicle fuel supply system comprising: separate first and second tanks each having a bottom and side walls, a fuel opening in one side wall of each tank, a single fuel filler neck for receiving fuel to be supplied to the said first and second tanks, a fuel filler pipe connected to said neck having first and second branches thereon connected by a crossover segment, said branches connected to said fuel oPenings in said first and second tanks for filling said tanks concurrently from said single fuel filler neck, first and second fuel suction lines located respectively within said first and second tanks each of said suction lines having an inlet opening at the tank bottom for directing fuel therefrom, a fuel pump for supplying fuel to a vehicle carburetor system including an inlet and an outlet, control means for selectively communicating one of said first and second suction lines in one of the tanks to said pump during a first pump-down phase, said crossover segment directing fuel from the other of the tanks to the one tank during the first pump-down phase whereby fuel level in each of said first and second tanks is lowered equally until the fuel level in said first and second tanks is lower than the bottom edge of said fuel openings, said crossover segment serving to disconnect the one tank from the other tank when the fuel level reaches a minimum level during the pump-down phase to retain a reserve of fuel in the other tank, said control means being operable to communicate the other tank to supply the reserve fuel to said pump during a second pump-down phase.

Claim 3

A vehicle fuel supply system comprising: separate first and second fuel tanks each having flat bottoms and a sidewall portion thereon with a fuel opening located on the horizontal center line of said sidewall to have a bottom edge located above the tank bottom, a single fuel filler neck for receiving fuel to be supplied to the said first and second tanks, a fuel filler pipe connected to said neck having first and second branches connected respectively to said fuel openings, a crossover segment between said branches, said crossover segment and said branches being located in a common plane including said fuel openings in said first and second tanks for filling said tanks concurrently from said single fuel filler neck, first and second fuel suction lines located respectively within said first and second tanks for directing fuel therefrom, a fuel selector valve having inlets connected to each of said lines and having an outlet, a fuel pump for supplying fuel to a vehicle carburetor system including an inlet and an outlet, a primary fuel suction line connecting said pump inlet to the outlet of said selector valve, means for conditioning said selector valve to communicate one of said first and second suction lines in one of the tanks to said pump during a first pump-down phase, said crossover segment directing fuel from the other tank to the one tank during the first pump-down phase whereby fuel level in each of said first and second tanks is lowered equally until the fuel level in said first and second tanks is lower than the bottom edge of said side openings, said crossover segment serving to disconnect the one tank from the other tank when the fuel level reaches a minimum level during the pump-down phase to retain a reserve of fuel in the other tank equal to the fuel volume between the tank bottom and the bottom edge of said side fuel opening in the other tank, said control means being operable to condition said selector valve to communicate the other tank to supply the reserve fuel to said pump during a second pump-down phase.

Claim 4

A vehicle fuel supply system comprising: separate first and second fuel tanks each having flat bottoms and a sidewall portion thereon with a fuel opening located on the horizontal center line of said sidewall to have a bottom edge located above the tank bottom, a single fuel filler neck for receiving fuel to be supplied to the said first and second tanks, a fuel filler pipe connected to said neck having first and second branches connected respectively to said fuel openings, a crossover segment between said branches, said crossover segment and said branches being located in a common plane including said fuel openings in said first and second tanks for filling said tanks concurrently from said single fuel filler neck, first and second fuel suction lines located respectively within said first and second tanks for directing fuel therefrom, a fuel selector valve having inlets connected to each of said lines and having an outlet, a fuel pump for supplying fuel to a vehicle carburetor system including an inlet and an outlet, a primary fuel suction line connecting said pump inlet to the outlet of said selector valve, means for conditioning said selector valve to communicate one of said first and second suction lines in one of the tanks to said pump during a first pump-down phase, said crossover segment directing fuel from the other tank to the one tank during the first pump-down phase whereby fuel level in each of said first and second tanks is lowered equally until the fuel level in said first and second tanks is lower than the bottom edge of said side openings, said crossover segment serving to disconnect the one tank from the other tank when the fuel level reaches a minimum level during the pump-down phase to retain a reserve of fuel in the other tank equal to the fuel volume between the tank bottom and the bottom edge of said side fuel opening in the other tank, said control means being operable to condition said selector valve to communicate the other tank to supply the reserve fuel to said pump during a second pump-down phase.

Claim 5

A vehicle fuel supply system comprising an auxiliary fuel tank and a separate main fuel tank, each of said tanks having a fuel fill opening therein with the bottom edge of said fuel fill opening at a point above the tank bottom, a single fuel filler neck for receiving fuel to be supplied to said first and second tanks, a fuel filler pipe connected to said neck having first and second branches thereon connected by a crossover segment, said pipe, branches and crossover segment being external of said tanks, each of said branches connecting said filler pipe to one of said tank fuel fill openings, first and second suction lines located respectively in said auxiliary and main fuel tanks, fuel pump means for supplying fuel to a vehicle carburetor system, control means for selectively communicating oNe or the other of said suction lines of said pump means for withdrawing fuel from said tanks, said crossover segment serving to intercommunicate said tanks during a first pump-down phase whereby fuel will be drawn equally from each of said tanks until the level in the auxiliary tank reaches a minimum point at the bottom edge of one of said fill openings, means including an auxiliary power fuel suction line in communication with said main fuel tank for supplying fuel to auxiliary power systems on a vehicle, said auxiliary power fuel suction line drawing fuel from said main tank during auxiliary power operation, said crossover segment communicating said main tank with auxiliary tank during auxiliary power operation to cause fuel to be drawn equally from said tanks until the level of fuel in said tanks reaches the minimum level at the bottom edge of said one fill opening with a reserve fuel supply being retained in said auxiliary tank equal to the fuel volume between the bottom of said auxiliary tank and the bottom edge of the one fill opening therein, said control means connecting the suction line in said auxiliary tank to the fuel pump during a second pump-down phase wherein the reserve fuel in the auxiliary tank is available for operating the vehicle.

Claim 6

A vehicle fuel supply system comprising an auxiliary fuel tank and a separate main fuel tank, each of said tanks having a fuel fill opening therein with the bottom edge of said fuel fill opening at a point above the tank bottom, a single fuel filler neck for receiving fuel to be supplied to said first and second tanks, a fuel filler pipe connected to said neck having first and second branches thereon connected by a crossover segment, said pipe, branches and crossover segment being external of said tanks, each of said branches connecting said filler pipe to one of said tank fuel fill openings, first and second suction lines located respectively in said auxiliary and main fuel tanks, fuel pump means for supplying fuel to a vehicle carburetor system, control means for selectively communicating oNe or the other of said suction lines of said pump means for withdrawing fuel from said tanks, said crossover segment serving to intercommunicate said tanks during a first pump-down phase whereby fuel will be drawn equally from each of said tanks until the level in the auxiliary tank reaches a minimum point at the bottom edge of one of said fill openings, means including an auxiliary power fuel suction line in communication with said main fuel tank for supplying fuel to auxiliary power systems on a vehicle, said auxiliary power fuel suction line drawing fuel from said main tank during auxiliary power operation, said crossover segment communicating said main tank with auxiliary tank during auxiliary power operation to cause fuel to be drawn equally from said tanks until the level of fuel in said tanks reaches the minimum level at the bottom edge of said one fill opening with a reserve fuel supply being retained in said auxiliary tank equal to the fuel volume between the bottom of said auxiliary tank and the bottom edge of the one fill opening therein, said control means connecting the suction line in said auxiliary tank to the fuel pump during a second pump-down phase wherein the reserve fuel in the auxiliary tank is available for operating the vehicle.

Claim 7

A vehicle fuel system comprising a pair of rectangular front and rear tanks located adjacent one another, a vehicle frame surrounding said tanks, one of said tanks being located forwardly of the other of said tanks within said frame, each of said tanks having a side fuel opening therein, a single fuel filler neck and fill pipe for said tanks including portions thereon connected to said tanks at the side openings therein, a fuel limiter line connected to the center of each of said tanks having an opened end located within said tank, each of the said tanks having an upper surface located above the opened end of said fuel limiter line to define a vapor expansion space in each of said tanks, a line connected to each of said fill limiter lines having an opened end thereon connected to said fuel filler neck, a liquid vapor separator including a container and four tubes located therein each having an upper open end at the top of the container and each protruding from the container exteriorly of the bottom thereof, first vent means for connecting one of said tubes to the forward side of the upper surface of the front tank, second vent means for connecting a second tube within said liquid vapor separator container to a rearwardly located portion of the top surface of said rear tank on the opposite side from the vent connection to the front tank, a vapor transfer line, means for connecting a third one of said tubes to said vapor transfer line, return means for connecting a fourth one of said tubes to the rear tank, said fourth tube having a notch therein at its base to drain liquid fuel from the bottom of said container to said return means, a restrictor in said vapor transfer line for restricting flow of fuel vapors from said container to maintain the majority of fuel vapors in said system within said front and rear fuel tanks, said first vent means being exposed to communicate the pair of tanks with atmosphere when the forward tank is tilted upwardly and the rearward tank is depressed, said second vent means being exposed to communicate both tanks with atmosphere when the forward tank is depressed and the rear tank is tilted upwardly, said single fill pipe serving to equalize pressure between said tanks from an exposed vent means in one of the tanks to a blocked vent means in the other of the tanks as produced by fore and aft tilting movements of said pair of tanks and said single fill pipe intercommunicating each of said tanks so that expansion of fuel in a tank tilted to have trapped air therein will expand through said single filler line and be directed into a tank with an open vent means.

Claim 8

A vehicle fuel system comprising a pair of rectangular front and rear tanks located adjacent one another, a vehicle frame surrounding said tanks, one of said tanks being located forwardly of the other of said tanks within said frame, each of said tanks having a side fuel opening therein, a single fuel filler neck and fill pipe for said tanks including portions thereon connected to said tanks at the side openings therein, a fuel limiter line connected to the center of each of said tanks having an opened end located within said tank, each of the said tanks having an upper surface located above the opened end of said fuel limiter line to define a vapor expansion space in each of said tanks, a line connected to each of said fill limiter lines having an opened end thereon connected to said fuel filler neck, a liquid vapor separator including a container and four tubes located therein each having an upper open end at the top of the container and each protruding from the container exteriorly of the bottom thereof, first vent means for connecting one of said tubes to the forward side of the upper surface of the front tank, second vent means for connecting a second tube within said liquid vapor separator container to a rearwardly located portion of the top surface of said rear tank on the opposite side from the vent connection to the front tank, a vapor transfer line, means for connecting a third one of said tubes to said vapor transfer line, return means for connecting a fourth one of said tubes to the rear tank, said fourth tube having a notch therein at its base to drain liquid fuel from the bottom of said container to said return means, a restrictor in said vapor transfer line for restricting flow of fuel vapors from said container to maintain the majority of fuel vapors in said system within said front and rear fuel tanks, said first vent means being exposed to communicate the pair of tanks with atmosphere when the forward tank is tilted upwardly and the rearward tank is depressed, said second vent means being exposed to communicate both tanks with atmosphere when the forward tank is depressed and the rear tank is tilted upwardly, said single fill pipe serving to equalize pressure between said tanks from an exposed vent means in one of the tanks to a blocked vent means in the other of the tanks as produced by fore and aft tilting movements of said pair of tanks and said single fill pipe intercommunicating each of said tanks so that expansion of fuel in a tank tilted to have trapped air therein will expand through said single filler line and be directed into a tank with an open vent means.

Claim 9

A vehicle fuel supply system comprising: first and second fuel tanks each having a bottom and a fuel opening in the side therEof with its bottom edge above said tank bottom, a single fuel filler neck for receiving fuel to be supplied to the said first and second tanks, a fuel filler pipe connected to said neck having first and second branches thereon connected by a crossover segment, said branches connected to said fuel openings in said first and second tanks for filling said tanks concurrently from said single fuel filler neck, first and second fuel suction lines located respectively within said first and second tanks, each of said suction lines having an inlet opening at the tank bottom for directing fuel therefrom, a fuel pump for supplying fuel to a vehicle carburetor system including an inlet and an outlet, control means for selectively communicating one of said first and second suction lines in one of the tanks to said pump during a first pump-down phase, said crossover segment directing fuel from the other of the tanks to the one tank during the first pump-down phase whereby fuel level in each of said first and second tanks is lowered equally until the level of fuel in said first and second tanks is lower than the bottom edge of said fuel openings at which time said crossover segment disconnects the one tank from the other tank to retain a reserve of fuel in the other tank, said control means being operable to communicate the other tank to supply the reserve fuel to said pump during a second pump-down phase, said first tank being located forwardly at said second tank, a liquid vapor separator including a container and four tubes located therein each having an upper end at the top of the container and each protruding from the container exteriorly of the bottom thereof, first vent means for connecting one of said tubes to the forward side of the upper surface of said first tank, second vent means for connecting a second tube within said liquid vapor separator container to a rearwardly located portion of the top surface of said second tank on the opposite side from the vent connection to said first tank, a vapor transfer line, means for connecting a third one of said tubes to said vapor transfer line, return means for connecting a fourth one of said tubes to a liquid fuel return line to said second tank, said fourth tube being notched at its base to drain liquid fuel into said return means, said first vent means being operative to communicate said first and second tanks with atmosphere when said first tank is tilted upwardly and said second tank is depressed, said second vent means serving to communicate both tanks with atmosphere when said first tank is depressed and said second tank is tilted upwardly.

Claim 10

A vehicle fuel supply system comprising: first and second fuel tanks each having a bottom and a fuel opening in the side therEof with its bottom edge above said tank bottom, a single fuel filler neck for receiving fuel to be supplied to the said first and second tanks, a fuel filler pipe connected to said neck having first and second branches thereon connected by a crossover segment, said branches connected to said fuel openings in said first and second tanks for filling said tanks concurrently from said single fuel filler neck, first and second fuel suction lines located respectively within said first and second tanks, each of said suction lines having an inlet opening at the tank bottom for directing fuel therefrom, a fuel pump for supplying fuel to a vehicle carburetor system including an inlet and an outlet, control means for selectively communicating one of said first and second suction lines in one of the tanks to said pump during a first pump-down phase, said crossover segment directing fuel from the other of the tanks to the one tank during the first pump-down phase whereby fuel level in each of said first and second tanks is lowered equally until the level of fuel in said first and second tanks is lower than the bottom edge of said fuel openings at which time said crossover segment disconnects the one tank from the other tank to retain a reserve of fuel in the other tank, said control means being operable to communicate the other tank to supply the reserve fuel to said pump during a second pump-down phase, said first tank being located forwardly at said second tank, a liquid vapor separator including a container and four tubes located therein each having an upper end at the top of the container and each protruding from the container exteriorly of the bottom thereof, first vent means for connecting one of said tubes to the forward side of the upper surface of said first tank, second vent means for connecting a second tube within said liquid vapor separator container to a rearwardly located portion of the top surface of said second tank on the opposite side from the vent connection to said first tank, a vapor transfer line, means for connecting a third one of said tubes to said vapor transfer line, return means for connecting a fourth one of said tubes to a liquid fuel return line to said second tank, said fourth tube being notched at its base to drain liquid fuel into said return means, said first vent means being operative to communicate said first and second tanks with atmosphere when said first tank is tilted upwardly and said second tank is depressed, said second vent means serving to communicate both tanks with atmosphere when said first tank is depressed and said second tank is tilted upwardly.