Pump and filter assembly for low viscosity fluids

Abstract

A hand operated pump and filter assembly for transferring low viscosity fluids, such as hydraulic oil, from a supply container to a machine requiring the fluid, and for filtering the fluid. The pump is a combination vacuum and displacement pump. The pump has a barrel with a cylindrical central passageway therein. A piston is positioned within the central passageway and is connected to the lower end of a piston rod. The upper end of the piston rod is attached to a handle for effecting upward and downward movement of the piston. The piston has fluid passageways extending therethrough and valve means associated with the fluid passageways to prevent fluid from flowing through the passageways during the piston upstroke but allowing fluid to flow through the passageways during the piston downstroke. The inlet end of the pump barrel has a valve subassembly means which seals communication between the central passageway thereof and a fluid supply container during the piston downstroke but opens communication during the piston upstroke. An adapter is provided for locking the pump barrel to the outlet of a fluid supply container. The outlet end of the pump barrel communicates with a filter via a conduit. The filter is preferably a ten micron filter for removing very fine impurities from the fluid being pumped. The outlet of the filter communicates with the machine to which the fluid is being transferred via a flexible conduit.