Patent ID: 7967578

Claim:
A piston type pumping apparatus configured for pumping a fluid, comprising: a vertically oriented cylinder having a top and bottom; a first passageway for hydraulic fluid adjacent to the bottom of the vertically oriented cylinder; a second passageway for the hydraulic fluid adjacent to the top of the vertically oriented cylinder; a piston reciprocatingly mounted within the vertically oriented cylinder having a top area against which the hydraulic fluid acts in a direction of movement of the piston and a bottom area against which the hydraulic fluid acts in the direction of movement of the piston; a hollow piston rod connected to the piston and mounted within the vertically oriented cylinder, wherein the hollow piston rod comprises a first one-way valve; a transfer chamber sealingly attached to the top of the vertically oriented cylinder at a position radially spaced apart from a first aperture such that a top portion of the hollow piston rod extends reciprocatingly and sealingly though the first aperture in the top of the vertically oriented cylinder and into the transfer chamber, wherein the first one-way valve is positioned to allow fluid flow from the hollow piston rod into the transfer chamber and wherein the piston rod does not contact an interior side surface of the transfer chamber; a discharge chamber located above and in fluid communication with the transfer chamber, wherein the discharge chamber and the transfer chamber are connected by a third one-way valve configured to allow fluid flow from the transfer chamber into the discharge chamber; a reload chamber located below the vertically oriented cylinder such that a bottom portion of the hollow piston rod extends reciprocatingly and sealingly through a second aperture in the bottom of the vertically oriented cylinder and into the reload chamber, wherein fluid in the reload chamber may flow into the bottom portion of the hollow piston rod, wherein an inside diameter of the vertically oriented cylinder is greater than an inside diameter of the reload chamber; and a second one-way valve located in the reload chamber, wherein the second one-way valve is positioned to allow fluid flow into the reload chamber from outside the piston type pumping apparatus.