# US 11,994,077 B2 · Fuel nozzle metering valve that provides dribble flow and related method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,994,077 B2 - Document ID: US11994077B2 - Status: Granted - Kind: B2 - Application number: 17/749,924 - Filed: 2022-05-20 - Published: 2023-11-23 - Granted: 2024-05-28 - Earliest claimed: 2022-05-20 - Assignees: Woodward, Inc. - Applicants: Sander G. Niemeyer; Deke R. Pyle - Inventors: Sander G. Niemeyer; Deke R. Pyle - Web page: https://patentgrep.com/patent/US11994077B2 ## CPC - F02C 9/263: {by means of fuel metering valves} - F02C 7/232: Fuel valves {(control of fuel supply by means of fuel metering valves F02C9/263)}; Draining valves or systems (valves in general F16K) - F16K 11/0716: {with fluid passages through the valve member (F16K11/0704, F16K11/0708, F16K11/0712 take precedence)} - F05D 2240/35: Combustors or associated equipment - F05D 2270/092: in particular blow-out and relight - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - 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)} - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract Embodiments of a metering valve for a fuel nozzle are disclosed. The metering valve includes a fitting having an interior cavity and an inlet, a liner disposed within the interior cavity, and a spool having an orifice. The liner includes inlet ports, and the spool is disposed within the liner. The spool is configured to slide within the liner to control flow between the inlet and the orifice. The spool has an open position in which the spool uncovers the inlet ports, a closed position in which the spool is seated against the fitting, and a lifted off position in which the spool is not seated against the fitting and covers the inlet ports. A dribble flow path through at least one of the spool or the liner provides fluid communication between the inlet and the orifice when the spool is in the lifted off position. ## Claims ### Claim 1 A metering valve for a fuel nozzle, comprising: a fitting having an interior cavity and an inlet; a liner disposed within the interior cavity, the liner comprising one or more inlet ports; a spool having an orifice, the spool being disposed within the liner; wherein the spool is configured to slide within the liner to control flow between the inlet and the orifice, the spool having an open position in which the spool uncovers the one or more inlet ports, a closed position in which the spool is seated against the fitting, and a lifted off position in which the spool is not seated against the fitting and covers the inlet ports; and wherein a dribble flow path through at least one of the spool or the liner provides fluid flow through the inlet and the orifice when the spool is in the lifted off position. ### Claim 2 (depends on 1) The metering valve of claim 1, wherein the dribble flow path is a clearance between the liner and the spool in a region between the one or more inlet ports and the inlet. ### Claim 3 (depends on 2) The metering valve of claim 2, wherein the clearance is created by a reduced diameter of the spool. ### Claim 4 (depends on 2) The metering valve of claim 2, wherein the clearance is created by a thinning of the liner in the region between the one or more inlet ports and the inlet. ### Claim 5 (depends on 1) The metering valve of claim 1, wherein the liner comprises an abutment region that contacts the fitting in a region between the one or more inlet ports and the inlet and wherein the dribble flow path extends from an interior surface of the liner through the abutment region to an exterior peripheral chamber between the fitting and liner that is downstream of the one or more inlet ports. ### Claim 6 (depends on 1) The metering valve of claim 1, wherein the spool comprises a spool head, a spool body, and a spool neck disposed between the spool head and the spool body; wherein the spool head comprises a spool face; wherein, in the closed position, the spool face abuts the fitting and the spool head is disposed between the inlet and the one or more inlet ports; and wherein the dribble flow path extends from the spool face through a thickness of the spool head such that the dribble flow path outlets into a peripheral chamber formed between the spool neck and the liner. ### Claim 7 (depends on 6) The metering valve of claim 6, wherein the dribble flow path is located proximal to a peripheral edge of the spool head. ### Claim 8 (depends on 6) The metering valve of claim 6, wherein the dribble flow path is formed in a peripheral edge of the spool head. ### Claim 9 (depends on 6) The metering valve of claim 6, wherein the fitting comprises a first interior surface and a second interior surface, the first interior surface and the second interior surface defining the interior cavity, wherein the second interior surface defines a seal groove in which a seal is seated, the seal engaging the spool face in the closed position, and wherein the dribble flow path is positioned in alignment with the seal or such that the seal is between the inlet and the dribble flow path in the closed position. ### Claim 10 (depends on 1) A fuel nozzle, comprising the metering valve of claim 1; a spring biasing the spool to the closed position, the spring having a first end and a second end and the first end of the spring being seated within a spring cavity formed in the spool; wherein the fitting forms a spring support, the second end of the spring contacting the spring support; wherein the fitting further comprises a nozzle section having a central passage in fluid communication with the orifice of the spool. ### Claim 11 (depends on 10) The fuel nozzle of claim 10, wherein the spool comprises a spool head, a spool body, and a spool neck disposed between the spool head and the spool body; and wherein the dribble flow path flows either through a thickness of the spool head or around the spool head from the inlet to a peripheral chamber formed between the spool neck and the liner. ### Claim 12 A method of increasing fuel flow through a metering valve of a fuel nozzle, the metering valve comprising a fitting, a liner disposed in the fitting, and a spool slidably disposed in the liner, the method comprising: flowing fuel through the metering valve from an inlet of the fitting through an orifice of the spool when the spool is positioned in the liner in a lifted off position that is between an open position and a closed position, wherein in the open position the spool uncovers one or more inlet ports of the liner and wherein in the closed position the spool is seated against the fitting. ### Claim 13 (depends on 12) The method of claim 12, wherein flowing further comprises flowing fuel through a clearance between the liner and the spool in a region between the one or more inlet ports and the inlet. ### Claim 14 (depends on 13) The method of claim 13, wherein the clearance is created by a reduced diameter of the spool. ### Claim 15 (depends on 13) The method of claim 13, wherein the clearance is created by a thinning of the liner in the region between the one or more inlet ports and the inlet. ### Claim 16 (depends on 12) The method of claim 12, wherein the liner comprises an abutment region that contacts the fitting in a region between the one or more inlet ports and the inlet; and wherein flowing further comprises flowing through a dribble flow path extending from an interior surface of the liner through the abutment region to an exterior peripheral chamber between the fitting and liner that is downstream of the one or more inlet ports. ### Claim 17 (depends on 12) The method of claim 12, wherein the spool comprises a spool head, a spool body, and a spool neck disposed between the spool head and the spool body; wherein the spool head comprises a spool face; wherein, in the closed position, the spool face abuts the fitting and the spool head is disposed between the inlet and the one or more inlet ports; and wherein flowing further comprises flowing fuel through a dribble flow path extending from the spool face through a thickness of the spool head into a peripheral chamber formed between the spool neck and the liner. ### Claim 18 (depends on 17) The method of claim 17, wherein the dribble flow path is located proximal to a peripheral edge of the spool head. ### Claim 19 (depends on 17) The method of claim 17, wherein the dribble flow path is formed in a peripheral edge of the spool head. ### Claim 20 (depends on 17) The method of claim 17, wherein the fitting comprises a first interior surface and a second interior surface, the first interior surface and the second interior surface defining an interior cavity, wherein the second interior surface defines a seal groove in which a seal is seated, the seal engaging the spool face in the closed position, and wherein the dribble flow path is positioned in alignment with the seal or such that the seal is between the inlet and the dribble flow path in the closed position.