Fluid pump with pressure relief path

Abstract

A liquid pump including a pump housing having an interior sidewall forming an interior. The housing has an inlet port and an outlet port. A liner is disposed in the interior and has opposed transverse openings in line with the inlet and outlet ports. The liner has a central longitudinally extending bore. A pump piston is axially and rotatably slidable within the liner longitudinal bore for pumping the liquid from the inlet port to the outlet port. A seal assembly is secured to the pump housing adjacent to an upper end of the liner. The seal assembly including a seal body, an upper end of the piston extending though the cap and in sealing engagement with the seal body, the seal assembly and liner upper end forming a cavity there between. An upper end of the piston extending though the seal assembly and in sealing engagement with the seal body, the seal body and liner upper end forming a cavity there between. The housing having a passageway providing a fluid communication between the cavity and the inlet port.

Dependencies are inferred from the claim text.