Abstract A pressure regulator for use in a fuel supply system such as might be found in a vehicle where fuel from a fuel tank is conveyed by a fuel pump to a carburetor is disclosed. The pressure regulator maintains the fuel pressure at the fuel pump outlet at a preferred level relative to atmospheric pressure and includes a regulator housing with a fuel inlet coupled to the fuel pump outlet and a fuel outlet coupled to the fuel system upstream of the fuel pump. A first pressure responsive surface such as a piston or diaphragm surface within the regulator is exposed to and actuable by fuel pressure at the regulator fuel inlet and a second pressure responsive surface having an area greater than the first surface is actuable by ambient atmospheric pressure with the two surfaces being coupled for conjoint movement to a position which adjusts fuel flow between the regulator inlet and outlet so long as the ratio of fuel pressure to atmospheric pressure is less than a preselected value while movement from that position to allow fuel flow between the inlet and outlet occurs when the ratio of fuel pressure to atmospheric pressure exceeds the preselected value. Typically the preselected value is numerically the ratio of the area of the second atmospheric pressure actuated surface to the area of the first or fuel actuated surface.
A pressure regulator for a vehicle fuel system having a fuel tank, a carburetor, a fuel pump, first means coupling the fuel tank to a fuel pump inlet, and second means coupling a fuel pump outlet to the carburetor, said pressure regulator maintaining the fuel pressure at the fuel pump outlet at a preferred level relative to atmospheric pressure and comprising: a regulator housing having a fuel inlet for coupling to the fuel pump outlet, and a fuel outlet for coupling to the fuel system upstream of the fuel pump; a diaphragm peripherally supported by the housing with one diaphragm surface comprising a pressure responsive surface exposed to and actuable by fuel pressure at the fuel inlet and another diaphragm surface exposed to and actuable by atmospheric pressure, the diaphragm being flexible between a first position to preclude fuel flow between the fuel inlet and the fuel outlet so long as the ratio of fuel pressure to atmospheric pressure is less than a preselected value and another position to allow fuel flow from the fuel inlet to the fuel outlet when the ratio of fuel pressure to atmospheric pressure exceeds the preselected value.
Claim 2
Dependent Claim
193 words
A pressure regulator for a vehicle fuel system having a fuel tank, a carburetor, a fuel pump, first means coupling the fuel tank to a fuel pump inlet, and second means coupling a fuel pump outlet to the carburetor, said pressure regulator maintaining the fuel pressure at the fuel pump outlet at a preferred level relative to atmospheric pressure and comprising: a regulator housing having a fuel inlet for coupling to the fuel pump outlet, and a fuel outlet for coupling to the fuel system upstream of the fuel pump; a diaphragm peripherally supported by the housing with one diaphragm surface comprising a pressure responsive surface exposed to and actuable by fuel pressure at the fuel inlet and another diaphragm surface exposed to and actuable by atmospheric pressure, the diaphragm being flexible between a first position to preclude fuel flow between the fuel inlet and the fuel outlet so long as the ratio of fuel pressure to atmospheric pressure is less than a preselected value and another position to allow fuel flow from the fuel inlet to the fuel outlet when the ratio of fuel pressure to atmospheric pressure exceeds the preselected value.
Claim 3
Dependent Claim
42 words
The pressure regulator of claim 1 including means limiting the area of the pressure responsive surface exposed to fuel pressure when the diaphragm is in the first position to less than the area of the another diaphragm surface exposed to atmospheric pressure.
Claim 4
Dependent Claim
33 words
The pressure regulator of claim 1 wherein the ratio of the area of the another diaphragm surface to the area of the pressure responsive surface exposed to fuel pressure is the preselected value.
Claim 5
Dependent Claim
43 words
The pressure regulator of claim 1 wherein fuel flows between the regulator fuel inlet and fuel outlet and then to the first means only during times of excessive fuel pressure, fuel flow from the fuel pump to the carburetor completely bypassing the regulator.