# US 8,770,217 B2 · Apparatus and methods for purging air from a fluid conveying tube > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,770,217 B2 - Document ID: US8770217B2 - Status: Granted - Kind: B2 - Application number: 12/863,560 - Filed: 2008-01-31 - Published: 2010-11-11 - Granted: 2014-07-08 - Earliest claimed: 2008-01-31 - Assignees: Hewlett-Packard Development Company, L.P. - Applicants: Christopher J. Arnold; Gregory K. Justice - Inventors: Christopher J. Arnold; Gregory K. Justice - Web page: https://patentgrep.com/patent/US8770217B2 ## CPC - F16K 24/04: for venting only (F16K24/02 takes precedence) - B41J 2/1707: {Conditioning of the inside of ink supply circuits, e.g. flushing during start-up or shut-down} - B41J 2/175: Ink supply systems {; Circuit parts therefor} - B41J 2/19: for removing air bubbles - Y10T 137/0324: With control of flow by a condition or characteristic of a fluid - Y10T 137/2931: Diverse fluid containing pressure systems - Y10T 137/309: Fluid sensing valve - F16K: VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING {(devices for emptying and evacuating the excess liquid in valves or conduits F16L55/07)} - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract An apparatus for purging air from a fluid conveying tube includes a housing member comprising an inner bore having an inlet and an outlet (115); and a vented piston member slidably disposed within the inner bore, the vented piston member comprising a filter element and at least one air vent. The filter element is configured to allow air to pass through the vented piston member to the at least one air vent and to prevent fluid from passing through the vented piston member to the at least one air vent. A method of purging accumulated air from a fluid conveying tube includes providing a vented piston member slidably disposed within a housing member; displacing air from the fluid conveying tube through a filter element disposed within the piston member using pressurized fluid; and displacing the piston member with the pressurized fluid; wherein the displacement of the piston member exposes an outlet for the pressurized fluid. ## Claims ### Claim 1 An apparatus for purging air from a fluid conveying tube, said apparatus comprising: a housing member comprising an inner bore having an inlet to receiving fluid into the inner bore from said fluid conveying tube and an outlet to output said fluid from said inner bore to said fluid conveying tube; and a vented piston member slidably disposed within said inner bore, said vented piston member comprising a filter element and at least one air vent; wherein movement of said piston member within said inner bore closes and opens said outlet of said inner bore; wherein said filter element is configured to allow air to pass through said vented piston member to said at least one air vent and to prevent fluid from passing through said vented piston member to said at least one air vent. ### Claim 2 An apparatus for purging air from a fluid conveying tube, said apparatus comprising: a housing member comprising an inner bore having an inlet and an outlet; and a vented piston member slidably disposed within said inner bore, said vented piston member comprising a filter element and at least one air vent; wherein said filter element is configured to allow air to pass through said vented piston member to said at least one air vent and to prevent fluid from passing through said vented piston member to said at least one air vent; and wherein said vented piston member is configured to be displaced within said bore by a pressurized fluid received through said inlet. ### Claim 3 (depends on 2) The apparatus of claim 2, wherein said vented piston member is further configured to allow said pressurized fluid to access said outlet in said housing member after said pressurized fluid displaces said vented piston member. ### Claim 4 (depends on 2) The apparatus of claim 2, further comprising a seal for receiving a vertex of said piston member when said piston member is displaced within said bore by said pressurized fluid. ### Claim 5 (depends on 2) The apparatus of claim 2, further comprising at least one seal disposed between said piston member and said housing member. ### Claim 6 (depends on 5) The apparatus of claim 5, further comprising at least two seals disposed between said piston member and said housing member, one of which moves past said outlet to fluid connect said outlet to said inlet when said piston member is displaced within said bore by said pressurized fluid. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein said filter element comprises at least one of: a sintered polyethylene, a bonded polyethylene fiber, a sintered polyethylene doped with salt, and a bonded polyethylene fiber doped with salt. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein a dopant of said filter element is effective to solidify a fluid flowing in said fluid conveying tube. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein said apparatus for purging air further comprises: an ink supply fluidly connected to said inlet by an ink conveying tube; and a printhead of a printing device fluidly connected to said outlet. ### Claim 10 (depends on 9) The apparatus of claim 9, further comprising a pressurization system for pressurizing ink in said ink conveying tube and said housing member. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein said vented piston member is further configured to slide within said bore when moved by pressurized ink to fluidly connect said inlet to said outlet. ### Claim 12 (depends on 11) The apparatus of claim 11, further comprising an upper piston air seal disposed within said inner bore, wherein said upper piston air seal is configured to engage said vented piston member when said vented piston member is displaced by said pressurized ink. ### Claim 13 (depends on 11) The apparatus of claim 11, further comprising at least two seals disposed between said piston member and said housing member, one of which moves past said outlet to fluid connect said outlet to said inlet when said piston member is displaced within said bore by said pressurized ink. ### Claim 14 A method of purging accumulated air from a fluid conveying tube, said method comprising: providing a vented piston member slidably disposed within a housing member; displacing air from said fluid conveying tube through a filter element disposed within said piston member using pressurized fluid; and displacing said piston member with said pressurized fluid; wherein said displacement of said piston member exposes an outlet for said pressurized fluid. ### Claim 15 (depends on 14) The method of claim 14, further comprising solidifying said fluid with a dopant in said filter element. ### Claim 16 (depends on 14) The method of claim 14, further comprising fluidly connecting said outlet with a printhead. ### Claim 17 (depends on 14) The method of claim 14, wherein said fluid conveying tube is connected to a printhead cartridge, said method comprising: shipping said fluid conveying tube and printhead cartridge dry; and performing said purging of accumulated air subsequent to said shipping and prior to operation of said printhead cartridge. ### Claim 18 (depends on 14) The method of claim 14, wherein said filter element comprises at least one of a sintered polyethylene, a bonded polyethylene fiber, a sintered polyethylene doped with salt, and a bonded polyethylene doped with salt. ### Claim 19 (depends on 14) The method of claim 14, further comprising venting said air through a vent in said housing member. ### Claim 20 (depends on 14) The method of claim 14, further comprising capturing said piston member in a seal when said piston member is displaced within said housing member to prevent said piston member from subsequently closing said outlet.