Solenoid latched diaphragm fuel shut-off valve assembly

Claim 2

A valve assembly for an engine fuel line including a fuel pump comprising, in combination: a valve in the fuel line having a closed position and an open position; spring means biasing the valve to its closed position; an expansible chamber motor actuable by the suction of the fuel pump to move the valve against the spring bias to its open position; a source of electric power; a solenoid assembly including an armature and a coil, the armature abutting the valve for co-movement therewith and defining a first position when the valve is in its closed position and a second position when the valve is in its open position, the coil being actuable by the electric power source to exert a magnetic force on the armature biasing the armature against the valve and opposing the spring bias, the magnetic force with the armature in its first position being less than that required to move the valve against the spring bias, the magnetic force increasing, as the armature moves from its first to its second position, by a greater amount than the spring bias increases as the valve moves from its closed to its open position to such an extent that the spring bias with the valve in its open position is less than the force required to move the valve to its closed position against the magnetic force.

Claim 3

A fuel shut-off valve assembly for use with an engine having an engine driven fuel pump, a fuel tank containing fuel for the engine, a source of electric power and a switch, the fuel shut-off valve assembly comprising, in combination: a housing with a movable wall, the housing defining a chamber having an inlet port connectable with the fuel tank for the admittance of fuel therefrom and an outlet port connectable to the fuel pump, the movable wall being actuable by decreased pressure within the chamber to move inward in the chamber when the outlet port is so connected and the fuel pump is driven; a valve in the inlet port, the valve defining a closed position for blocking fuel flow through the inlet port and an open position for allowing fuel flow through the inlet port, the valve being linked to the movable wall for co-movement therewith from its closed position to its open position when the movable wall is actuated; a spring biasing the valve toward its closed position; a solenoid attached to the chamber, the solenoid including a coil and an armature, the armature being adapted To be forced to a first position by the valve when the valve moves to its closed position and being free to move with the valve to a second position when the valve moves to its open position, the coil being connectable to the electric power source through the switch for energization when the switch is closed, the coil being effective to exert a magnetic force on the armature biasing the armature toward its second position, the magnetic force with the solenoid in its first position being less than that required to move the valve from its closed position against said spring bias, the magnetic force increasing as the armature moves from its first position to its second position upon actuation of the movable wall, the increase in magnetic force being greater than the increase in the bias of the spring as the valve moves from its closed position to its open position by such an amount that the bias of the spring is less than that required to move the valve from its open position to its closed position against the magnetic force.

Claim 4

A fuel shut-off valve assembly for use with an engine having an engine driven fuel pump, a fuel tank containing fuel for the engine, a source of electric power and a switch, the fuel shut-off valve assembly comprising, in combination: a housing with a movable wall, the housing defining a chamber having an inlet port connectable with the fuel tank for the admittance of fuel therefrom and an outlet port connectable to the fuel pump, the movable wall being actuable by decreased pressure within the chamber to move inward in the chamber when the outlet port is so connected and the fuel pump is driven; a valve in the inlet port, the valve defining a closed position for blocking fuel flow through the inlet port and an open position for allowing fuel flow through the inlet port, the valve being linked to the movable wall for co-movement therewith from its closed position to its open position when the movable wall is actuated; a spring biasing the valve toward its closed position; a solenoid attached to the chamber, the solenoid including a coil and an armature, the armature being adapted To be forced to a first position by the valve when the valve moves to its closed position and being free to move with the valve to a second position when the valve moves to its open position, the coil being connectable to the electric power source through the switch for energization when the switch is closed, the coil being effective to exert a magnetic force on the armature biasing the armature toward its second position, the magnetic force with the solenoid in its first position being less than that required to move the valve from its closed position against said spring bias, the magnetic force increasing as the armature moves from its first position to its second position upon actuation of the movable wall, the increase in magnetic force being greater than the increase in the bias of the spring as the valve moves from its closed position to its open position by such an amount that the bias of the spring is less than that required to move the valve from its open position to its closed position against the magnetic force.