Two stage float valve
AssigneeThe United States of America as represented by the Secretary of the Army
InventorGalal N. Matta
Life of this patent
Estimating the term…
Abstract
A normally-open two stage float valve for use with a suction tube leading om a vehicle fuel tank. As the fuel tank begins to run dry it is desired that the float valve close off the tank to the suction force. The valve of this invention includes a float-operated pilot valve element that equalizes forces on the opposite faces of the main valve element as the float moves through its actuation stroke. A lifting head is associated with the pilot valve element for mechanically lifting or lowering the main valve element relative to the main seat when the forces have been equalized.
Claims3
In a vehicle having a liquid fuel tank whose bottom wall (12) is connected to a downwardly-extending suction tube (20):
- the improvement comprising means defining a main valve seat (22) located at the upper end of the suction tube;
- a main poppet valve element (34) disposed above the main seat for movement toward or away therefrom to control fuel flow thereacross;
- a stationary end wall (30) located above the valve seat;
- a first outer imperforate bellows 32 extending downwardly from said end wall to the main valve element;
- said main valve element having a pilot port (36) therethrough;
- a liquid-level responsive float (44) located within the fuel tank directly above the stationary end wall;
- a pilot valve element (40) rigidly connected to the float for opening the pilot port when the liquid level in the tank rises above a predetermined low value;
- valve lifter means (48) carried by the pilot valve element for forcible engagement with an undersurface of the main valve element when the pilot valve element is moved upwardly by the float;
- and a second inner imperforate bellows extending downwardly from the stationary end wall to the pilot valve element;
- the inner and outer bellows collectively forming an annular chamber (38) whose sole communication with the fuel tank is through the pilot port.
Dependencies are inferred from the claim text.