Tank pressure control valve

An apparatus for controlling discharge of fuel vapors from a fuel tank during refueling, the apparatus comprising

• means for conducting fuel vapor between the fuel tank and a fuel vapor treatment site situated outside of the fuel tank,
• means for selectively blocking flow of fuel vapor through the conducting means, the blocking means being operable between a flow-blocking position and a flow-delivery position,
• means for yieldably biasing the blocking means toward its flow-blocking position,
• means defining a venting control chamber in communication with the blocking means for receiving and using fuel vapor pressure from the fuel tank having a magnitude in excess of a predetermined threshold level to exert an opening force on the blocking means in opposition to the biasing means so that the blocking means is moved to its flow-delivery position, thereby permitting discharge of pressurized fuel vapor in the tank to said fuel vapor treatment site through the conducting means,
• means for communicating fuel vapor from the conducting means to at least one of the atmosphere and another fuel vapor treatment site, valve means for selectively blocking flow of fuel vapor through the communicating means, the valve means being operable between a flow-blocking position and flow-delivery positions, and auxiliary biasing means for yieldably biasing the valve means toward its flow-blocking position, the using means including control means communicating with the venting control chamber for using fuel vapor pressure in the fuel tank having a magnitude in excess of a greater second predetermined threshold level to exert an opening force on the valve means so that the valve means is moved in opposition to the auxiliary biasing means to its flow-delivery position, thereby permitting discharge of pressurized fuel vapor in the tank to another fuel vapor treatment site through the conducting means and the communicating means.

An apparatus for controlling discharge of fuel vapors from a fuel tank during refueling, the apparatus comprising

• means for conducting fuel vapor between the fuel tank and a fuel vapor treatment site situated outside of the fuel tank,
• means for selectively blocking flow of fuel vapor through the conducting means, the blocking means being operable between a flow-blocking position and a flow-delivery position, the blocking means including an actuator stem extending through the conducting means and means coupled to the actuator stem for sealingly engaging the conducting means upon movement of the blocking means to its flow-blocking position,
• means for yieldably biasing the blocking mean toward its flow-blocking position, and
• means for using fuel vapor in the fuel tank having a pressure in excess of a predetermined threshold level to exert an opening force on the blocking means in opposition to the biasing means so that the blocking means is moved to its flow-delivery position, thereby permitting discharge of pressurized fuel vapor in the tank to said fuel vapor treatment site through the conducting means, the using means including a cover member and barrier member sealingly coupled to the cover member for movement relative to the cover member to define a venting control chamber therebetween, the actuator stem being coupled to the movable barrier member and to the engaging means to move in unison therewith, and the movable barrier member and the actuator stem operating to define means for selectively establishing fluid communication between the fuel tank and the venting control chamber so that fuel tank pressure in excess of the predetermined threshold level communicated to the venting control chamber acts upon the barrier member to apply a movement-inducing force in opposition to force provided by the biasing means sufficient to move the engaging means away from sealing engagement with the conducting means to establish the flow-delivery position of the blocking means.

An apparatus for controlling discharge of fuel vapors from a fuel tank during refueling, the apparatus comprising

• means for conducting fuel between the fuel tank and a fuel vapor treatment site situated outside of the fuel tank,
• means for selectively blocking flow of fuel vapor through the conducting means, the blocking means being operable between a flow-blocking position and a flow-delivery position,
• means for yieldably biasing the blocking means towards its flow-blocking position, and
• means for using fuel vapor in the fuel tank having a pressure in excess of a predetermined threshold level to exert an opening force on the blocking means so that the blocking means is moved in opposition to the biasing means to its flow-delivery position, thereby permitting discharge of pressurized fuel vapor in the tank to said fuel vapor treatment site through the conducting means, the using means including a cover coupled to the conducting means, a primary actuation member, and means for coupling the primary actuation member to the cover to permit relative movement between the primary actuation member and the cover, the cover, primary actuation member, and coupling means cooperating to define venting control chamber means for containing pressurized fuel vapor in a predetermined region permitting pressurized fuel vapor to exert said opening force on the primary actuation member, the primary actuation member being coupled to the blocking means so that the blocking means moves towards its flow-delivery position in response to exertion of said opening force on the primary actuation member.

An apparatus for controlling discharge of fuel vapors from a fuel tank during refueling, the apparatus comprising

• means for conducting fuel vapor between the fuel tank and a fuel vapor treatment site situated outside of the fuel tank,
• means for selectively blocking flow of fuel vapor through the conducting means, the blocking means being operable between a flow-blocking position and a flow-delivery position,
• means for yieldably biasing the blocking means toward its flow-blocking position, and
• means for using fuel vapor in the fuel tank having a pressure in excess of a predetermined threshold level to exert an opening force on the blocking means in opposition to the biasing means so that the blocking means is moved to its flow-delivery position, thereby permitting discharge of pressurized fuel vapor in the tank to said fuel vapor treatment site through the conducting means, the conducting means being formed to including a valve seat having an inner edge defining a venting aperture, the using means including first and second walls sealably coupled together and movable relative to one another to define an expandable and contractible venting control chamber therebetween, and the blocking means including a venting valve member that is movable between a flow-blocking position engaging the valve seat to close the venting aperture and a flow-delivery position away from the valve seat opening the venting aperture, and a stem interconnecting the venting valve member and the second wall, the venting valve member being formed to include a central aperture communicating with the fuel tank, the second wall being formed to include a central aperture providing an opening into the venting control chamber, the biasing means acting between the conducting means and the second wall normally to urge the second wall toward the first wall to contract the volume control chamber to urge the venting valve member to its flow-blocking position, the stem being formed to include means interconnecting the central apertures of the second wall and the venting valve member for communicating pressurized fuel vapor from the fuel tank to the venting control chamber so that the second wall moves relative to the first wall in opposition to the biasing means to expand the volume of the venting control chamber and urge the venting valve member toward its flow-delivery position.

An apparatus for controlling discharge of fuel vapors from a fuel tank having an outlet during refueling, the apparatus comprising

• means for dividing the outlet into separate first and second fuel vapor flow ports so that pressurized fuel vapor in the fuel tank is exhaustible therefrom through said ports,
• vapor delivery means for conducting fuel vapor from the first port to at least one fuel vapor treatment site, and
• control means for using pressurized fuel vapor discharged through the fuel tank outlet via the second fuel vapor flow port to regulate the flow of fuel vapors through the first fuel vapor flow port so that fuel vapor in the fuel tank can be selectively discharged through the fuel tank outlet via the first fuel vapor flow port and recovered at the at least one fuel vapor treatment site during refueling, the control means including a valve member movable between a first position blocking flow of fuel vapor through the first fuel vapor flow port and a second position permitting flow of fuel vapor through the first fuel vapor flow port, the valve member being formed to include a central aperture defining the second fuel vapor flow port, means for yieldably biasing the valve member toward its first position, venting control chamber means for containing pressurized fuel vapor in a predetermined region, the venting control chamber means including a movable actuation pad having an interior surface defining a portion of the boundary of the predetermined region, means for interconnecting the movable actuation pad and the valve member so that the valve member moves in unison with the actuation pad, and passageway means for conducting pressurized fuel vapor from the central aperture to the predetermined region to permit pressure in excess of a predetermined threshold level communicated to the predetermined region by the passageway means to exert sufficient force on the actuation pad to overcome the force of the biasing means so that the valve member is moved toward its second position.

A system for handling fuel vapors from a vehicle fuel system, the vehicle fuel system including a fuel tank and means for processing fuel vapor, the system comprising

• means for conducting fuel vapor between the fuel tank and the processing means,
• means for selectively blocking flow of fuel vapor through the conducting means, the blocking means including a valve member situated in the fuel tank and an actuator pad situated outside the fuel tank, and means for interconnecting the valve member and the actuator pad for movement in unison, the valve member being operable between a flow-blocking position, and flow-delivery positions,
• means for yieldably biasing the actuator pad to a position corresponding with the flow-blocking position of the blocking means,
• means for communicating a closing pressure generated by fuel vapor in the fuel tank actuator pad to change the valve member to its flow-blocking position, and
• means for selectively venting the communicating means to the atmosphere to dissipate any closing pressure therein to permit the biasing means to urge the valve member from its flow-delivery position to its flow-blocking position in response to lowering of the closing pressure to a magnitude less than a predetermined level.