Patent ID: 6171081
Filing Date: 2001-01-09
Classification: F02M,F04B

Abstract:
A fuel pump assembly comprising:a lower pump body;an upper pump body;a pump diaphragm clamped between said lower pump body and said upper pump body and defining a pump chamber and an operation chamber;a diaphragm rod integrally mounted on said pump diaphragm and being slidably supported on said lower pump body;a push rod supported for movement along a longitudinal direction of said diaphragm rod, said push rod being movably supported within a push rod guide hole opened downwardly in said lower pump body, and having a lower end extended downwardly from said lower pump body;a push rod spring disposed within said push rod guide hole in compressed fashion, arranged on the outer periphery of said diaphragm rod, engaged with an upper bottom portion of said push rod guide hole at an upper end and engaged with said push rod at a lower end, for resiliently pushing said push rod toward a pin mounted on said diaphragm rod for engagement;a diaphragm spring disposed within said operation chamber in compressed fashion and depressing said pump diaphragm toward said pump chamber; andsaid push rod spring comprising a first push rod spring having a larger diameter and a second push rod spring having a smaller diameter, respective lower ends of said first push rod spring and said second push rod spring being engaged with a bottom portion of an upwardly opened recessed portion of said push rod and respective upper ends thereof being engaged with the upper bottom portion of said push rod guide hole.