US Patent 9261085 Fluid pump having liquid reservoir and modified pressure relief slot

A pump, which generally includes a pump housing and a pump piston. The pump housing defines a central longitudinal bore, a transverse bore communicating with the central bore for conveying a liquid through the pump housing, a liquid reservoir communicating with the central bore and the transverse bore for retaining an amount of the liquid conveyed through the transverse bore and a pressure relief slot extending from the transverse bore to the liquid reservoir. The pump piston is axially and rotatably slidable within the central longitudinal bore for pumping the liquid through the transverse bore.