On board refueling vapor recovery system

In a vehicle having an internal combustion engine, and a fuel supply system including a refillable fuel storage tank for supplying volatile fuel to said engine, said fuel tank including a filler pipe having an inlet end adapted to receive an elongate tubular fuel dispensing nozzle of a standard diameter to accommodate refueling of said vehicle from an external source of volatile fuel;

• the improvement comprising an onboard refueling vapor recovery system mounted in said vehicle for storing and disposing of fuel vapor displaced from said fuel tank by the refueling of said tank with volatile fuel, said recovery system comprising nozzle receiving seal means located adjacent said inlet end of said filler pipe normally sealing said inlet end against the discharge of fuel vapor into the atmosphere from said fuel tank through said filler pipe and operable to accommodate the insertion of a tubular fuel dispensing nozzle of standard diameter into said filler pipe through said sealing means to refill said tank with fuel while maintaining said inlet end sealed against the discharge of fuel vapor into the atmosphere, a refueling vapor storage canister mounted in said vehicle, first conduit means for conducting fuel vapor displaced from said tank during the refueling of said tank with volatile fuel from said tank into said storage canister, first valve means operable in a normally closed position to prevent the flow of vapor from said tank to said canister via said first conduit means and operable in an actuated open position to permit the flow of fuel vapor from said tank through said first conduit means into said canister, actuating means responsive to the insertion of said nozzle through said sealing means for actuating said first valve means to its open position, means responsive to the operation of said engine for conducting fuel vapor at a controlled rate from said canister to said engine for combustion in said engine, said seal means comprising a wall extending across the interior of said filler pipe to divide said filler pipe into a first section open to the inlet end of said pipe and a second section opening into said fuel tank, means defining a passage through said wall, having an annular seal adapted to slidably and sealingly engage a tubular nozzle of standard diameter projected axially through said passage to establish a vapor tight seal between the exterior of the nozzle and said wall, and said actuating means comprises a trap door like valve plate mounted in said second section of said pipe for hinging movement between a normally maintained closed position adjacent said wall sealing said passage from said second section and an open position wherein said plate is hinged clear of said passage by the insertion of said nozzle through said passage, means defining a bypass passage having an inlet opening into said second section of said pipe and an outlet opening into said first section of said pipe, first normally closed one way valve means in said passage accommodating flow in a direction from said inlet to said outlet and resilient means for maintaining said one way valve means closed until the pressure in said second section rises to a predetermined emergency pressure.

In a vehicle having an internal combustion engine, and a fuel supply system including a refillable fuel storage tank for supplying volatile fuel to said engine;

• the improvement comprising an onboard refueling vapor recovery system for storing and disposing of fuel vapor displaced from said fuel tank by the refueling of said tank with volatile fuel, said recovery system comprising a tank valve housing mounted upon the top of said fuel tank having a first inlet passage opening into the interior of said tank and first outlet at the exterior of said tank, a refueling vapor storage canister mounted in said vehicle, first conduit means defining a first fuel vapor flow passage extending from said tank valve outlet into said refueling canister, first valve means operable in a normally maintained closed position to block the flow of vapor from said tank through said first flow passage and operable in an actuated open position to accommodate flow of vapor from said tank through said first passage into said canister, actuating means responsive to the initiation of a tank refueling operation for actuating said first valve means to said open position and maintaining said first valve means in said open position until the refueling operation is terminated, normally open float valve means in said tank operable to block the flow of vapor from said tank into said flow passage when the level of fuel within said tank rises to or above a predetermined level, means in said tank valve housing defining a second vapor flow passage extending through said housing from a second inlet opening into said tank to a second outlet at the exterior of said tank, a running vapor canister mounted in said vehicle, second conduit means defining a second fuel vapor flow passage extending from said second outlet to said running vapor canister, and engine operation responsive means for transferring fuel vapor from said refueling and said running vapor canisters to said engine for combustion in said engine.

In a vehicle having an internal combustion engine, a fuel supply system including a fuel tank for supplying volatile fuel to said engine and a fuel tank fill pipe having a pipe inlet for receiving a tubular fuel dispensing nozzle of standard diameter to accommodate refueling of said tank, a running vapor canister vented to atmosphere mounted on said vehicle, first conduit means establishing a direct vapor flow passage between the head space of said fuel tank and said running vapor canister, and purge means having an inlet connected to an outlet of said running vapor canister for withdrawing fuel vapor from said running vapor canister for combustion in said engine;

• the improvement comprising a refueling vapor recovery system connected between the head space of said tank and the inlet of said purge means in parallel with said running vapor canister, said refueling vapor recovery system being operable to prevent fuel vapor displaced from said tank during a refueling operation from being vented into the atmosphere and comprising a refueling vapor canister mounted on said vehicle, first conduit means establishing a main valve controlled vapor flow passage between the head space of said tank and said refueling vapor canister, first normally closed valve means in said first conduit means operable when closed to block the flow of vapor through said main flow passage and operable in an actuated open position to accommodate the flow of vapor through said main flow passage, actuating means responsive to the presence of said nozzle in said inlet for actuating said first valve means to its open position, said main flow passage accommodating a substantially greater flow of vapor than said direct vapor flow passage, float valve means responsive to the level of fuel in said tank for blocking the flow of vapor from said tank into said main flow passage when the level of fuel within said tank is at or above a predetermined level, vacuum/pressure relief valve means responsive to the pressure differential between said refueling vapor canister and the head space of said fuel tank for accommodating the flow of vapor between said refueling canister and said head space maintain the pressure in said head space between predetermined upper and lower end limits when said first valve means is in its closed position.

In a vehicle having an internal combustion engine, a fuel supply system including a fuel tank for supplying volatile fuel to said engine and a fuel tank fill pipe having a pipe inlet for receiving a tubular fuel dispensing nozzle of standard diameter to accommodate refueling of said tank, a running vapor canister vented to atmosphere mounted on said vehicle, first conduit means establishing a direct vapor flow passage between the head space of said fuel tank and said running vapor canister, and purge means having an inlet connected to an outlet of said running vapor canister for withdrawing fuel vapor from said running vapor canister for combustion in said engine;

• the improvement comprising a refueling vapor recovery system connected between the head space of said tank and the inlet of said purge means in parallel with said running vapor canister, said refueling vapor recovery system being operable to prevent fuel vapor displaced from said tank during a refueling operation from being vented into the atmosphere and comprising a refueling vapor canister mounted on said vehicle, first conduit means establishing a main valve controlled vapor flow passage between the head space of said tank and said refueling vapor canister, first normally closed valve means in said first conduit means operable when closed to block the flow of vapor through said main flow passage and operable in an actuated open position to accommodate the flow of vapor through said main flow passage, actuating means responsive to the presence of said nozzle in said inlet for actuating said first valve means to its open position, said main flow passage accommodating a substantially greater flow of vapor than said direct vapor flow passage, float valve means responsive to the level of fuel in said tank for blocking the flow of vapor from said tank into said main flow passage when the level of fuel within said tank is at or above a predetermined level, nozzle receiving trap door seal means in said pipe inlet normally sealing the head space of said tank from said pipe inlet and operable to accommodate the insertion of said nozzle into said pipe inlet while maintaining said pipe inlet sealed against the discharge of vapor from said tank, vacuum/pressure relief valve means responsive to the pressure differential between said refueling vapor canister and the head space of said fuel tank for accommodating the flow of vapor between said refueling canister and said head space maintain the pressure in said head space between predetermined upper and lower end limits when said first valve means is in its closed position.

An improvement in a vehicle having an internal combustion engine, a fuel supply system including a refillable fuel storage tank for supplying volatile fuel to said engine and a running vapor recovery system including a canister for storage of running vapor only;

• said improvement comprising a separate onboard refueling vapor recovery system for storing and disposing of fuel vapor displaced from the fuel tank by the refueling of the tank with volatile fuel, said refueling vapor recovery system comprising a tank valve housing mounted upon the top of the fuel tank and having a first inlet passage opening into the interior of the tank and first outlet at the exterior of the tank, a separate refueling vapor only storage canister mounted in the vehicle, first conduit means defining a first fuel vapor flow passage extending from the tank valve outlet into said refueling canister, first valve means operable in a normally maintained closed position to block the flow of refueling vapor from the tank through said first flow passage and operable in an actuated open position to accommodate flow of refueling vapor from the tank through said first passage into said canister, actuating means responsive to the initiation of a tank refueling operation for actuating said first valve means to said open position and maintaining said first valve means in said open position until the refueling operation is terminated, and normally open float valve means in said tank operable to block the flow of vapor from the tank into said flow passage when the level of fuel within said tank rises to or above a predetermined level.

An improvement in a vehicle having an internal combustion engine, a fuel supply system including a fuel tank for supplying volatile fuel to said engine and a fuel tank fill pipe having an inlet for receiving a tubular fuel dispensing nozzle of standard diameter to accommodate refueling of said tank, a first running vapor canister vented to atmosphere mounted on said vehicle, first conduit means establishing a direct running vapor flow passage between the head space of the fuel tank and the running vapor canister, and purge means having an inlet connected to an outlet of the running vapor canister for withdrawing fuel vapor from the running vapor canister for combustion in the engine;

• said improvement comprising a refueling vapor recovery system connected between the head space of the tank and the inlet of the purge means, in parallel with said running vapor canister, said refueling vapor recovery system being operable to prevent fuel vapor displaced from the tank during a refueling operation from being vented into the atmosphere and comprising a second refueling-vapor-only canister mounted on the vehicle, second conduit means providing a main vapor flow passage between the head space of the tank and said refueling vapor canister, normally closed valve means in said second conduit means operable when closed to block the flow of refueling vapor through said main vapor flow passage and operable in an actuated open position to accommodate the flow of refueling vapor through said main vapor flow passage, actuating means responsive to the presence of the nozzle in the fill pipe inlet for actuating said valve means to its open position, said main vapor flow passage accommodating a substantially greater flow of vapor than said direct running vapor flow passage.

A method for preventing fuel vapor displaced from the fuel tank inlet of an internal combustion engine powered vehicle during refueling of said tank from being discharged into the atmosphere comprising the steps of

• 1. sealing the inlet through which fuel is introduced into said tank from an external fuel supply source, the external fuel supply source including a tubular fuel dispensing nozzle of standard outer diameter insertable into the fuel tank inlet to dispense fuel into said tank against the discharge of fuel vapor while said tank is being refueled,
• 2. venting fuel vapor displaced from said tank during the refueling operation into a refueling-vapor-only canister mounted in the vehicle,
• 3. terminating the venting of refueling fuel vapor from said tank into said refueling-vapor-only canister upon the completion of said refueling operation,
• 4. intermittantly conducting fuel vapor from said refueling-vapor-only canister to said engine for combustion by said engine.