Patent attributes
A piston cartridge having a piston chamber, an inlet port, an outlet port, and a piston moveable between a first position and a second position. Also, the cartridge includes a first barrier positioned between the piston and the inlet port and a first sealing member moveable between the first barrier and the inlet port, wherein the first sealing member seals the inlet port when positioned adjacent to the inlet port but allows the fluid into the chamber when positioned adjacent to the first barrier. In addition, the cartridge also includes a second barrier positioned adjacent to the outlet port and a second sealing member moveable between the piston and the second barrier, wherein the second sealing member seals the outlet port when positioned adjacent thereto but allows the fluid to pass through the outlet port when positioned adjacent to the second barrier.
