# US 2023/0054950 A1 · Plunger seal assembly and sealing method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0054950 A1 - Document ID: US20230054950A1 - Status: Published application - Kind: A1 - Application number: 17/407,439 - Filed: 2021-08-20 - Published: 2023-02-23 - Earliest claimed: 2021-08-20 - Assignees: General Electric Company - Applicants: General Electric Company - Inventors: James Shealy - Web page: https://patentgrep.com/patent/US20230054950A1 ## CPC - F02K 1/805: {Sealing devices therefor, e.g. for movable parts of jet pipes or nozzle flaps} - F01D 11/005: {Sealing means between non relatively rotating elements} - F01D 25/30: Exhaust heads, chambers, or the like - F01D 25/005: {Selecting particular materials} - F05D 2240/55: Seals - F05D 2300/20: Oxide or non-oxide ceramics - F02K: JET-PROPULSION PLANTS (features of jet-propulsion plants common to gas-turbine plants, air intakes or fuel supply control of air-breathing jet-propulsion plants F02C7/00, F02C9/00) - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract In some embodiments, apparatuses are provided herein useful to sealing a gap between a movable flap and stationary structure, such as a gap between a gas turbine engine nozzle flap and sidewall. An apparatus for sealing such a gap may be a plunger seal which may include a plurality of plunger segments connected together using at least one flexure. When positioned in the gap, the flexures within the plunger segments pivot allowing rotation of each of the plurality of plunger segments about their respective pivot point, such that the plunger assembly seals and contours against the movable surface. ## Claims ### Claim 1 A plunger seal apparatus for sealing a gap, the plunger seal apparatus comprising: a first plunger segment having a first proximal end, a first distal end, and a first channel defined therein; a second plunger segment having a second proximal end, a second distal end, and a second channel defined therein; and a first flexure secured within the first channel and the second channel for coupling the first plunger segment to the second plunger segment, a placement of the first flexure defining a predetermined distance between the first distal end and the second proximal end and forming a plunger channel through the first channel and the second channel. ### Claim 2 (depends on 1) The plunger seal apparatus of claim 1, wherein the first flexure has a head portion coupled to the first plunger segment and two stem portions coupled to an inner surface of the second plunger segment. ### Claim 3 (depends on 2) The plunger seal apparatus of claim 2, wherein the head portion of the first flexure is configured to pivot about a centroid located within a third plunger segment, the third plunger segment located adjacent to the first plunger segment. ### Claim 4 (depends on 1) The plunger seal apparatus of claim 1, wherein the first flexure, the first plunger segment, and the second plunger segment are each comprised of at least one of a metallic material and a ceramic material. ### Claim 5 (depends on 1) The plunger seal apparatus of claim 1, further comprising a seal housing disposed within the gap and enclosed about a portion of the first plunger segment and the second plunger segment. ### Claim 6 (depends on 1) The plunger seal apparatus of claim 1, further comprising an actuation mechanism adjacent to at least one of the first plunger segment and the second plunger segment to urge at least one of the first plunger segment and the second plunger segment towards a stationary structure at least partially defining the gap. ### Claim 7 (depends on 1) The plunger seal apparatus of claim 1, wherein the plunger seal apparatus is configured to operate in temperatures between 500 and 2000 degrees Fahrenheit. ### Claim 8 An exhaust nozzle for an engine, comprising: a sidewall; a movable flap adjacent the sidewall; and a plunger seal apparatus disposed between the sidewall and the movable flap to seal a gap between the sidewall and the movable flap, the plunger seal apparatus being configured to contour along at least a portion of the movable flap when the exhaust nozzle is in operation, the plunger seal apparatus comprising: a plurality of flexures; and a plurality of plunger segments, including at least a first plunger segment and a second plunger segment, the first plunger segment being coupled to the second plunger segment via at least one of the plurality of flexures, and wherein the plurality of plunger segments are connected end to end such that a channel is defined within the plunger seal apparatus. ### Claim 9 (depends on 8) The exhaust nozzle of claim 8, wherein each of the plurality of flexures comprises a head and two stem portions secured within neighboring plunger segments. ### Claim 10 (depends on 9) The exhaust nozzle of claim 9, wherein a pivot point of a given flexure within the plurality of flexures is located in a centroid within a neighboring plunger segment that is different than a plunger segment in which the head is secured. ### Claim 11 (depends on 8) The exhaust nozzle of claim 8, wherein the plurality of plunger segments are located at a predetermined distance between each other based on a placement of the plurality of flexures coupled thereto. ### Claim 12 (depends on 8) The exhaust nozzle of claim 8, wherein a material of the plurality of flexures is comprised of at least one of a metallic material and a ceramic material; and wherein a material of the plurality of plunger segments is comprised of at least one of a metallic material and a ceramic material. ### Claim 13 (depends on 8) The exhaust nozzle of claim 8, wherein the first plunger segment is further coupled to a third plunger segment using another one of the plurality of flexures. ### Claim 14 (depends on 8) The exhaust nozzle of claim 8, wherein the plurality of plunger segments comprise at least one of a plurality of machined plunger segments, plurality of stamped plunger segments, plurality of casted plunger segments, and plurality of additively manufactured plunger segments. ### Claim 15 A method of sealing a gap, the method comprising: positioning a plunger seal apparatus within the gap and against a movable surface, the plunger seal apparatus having a plurality of plunger segments interconnected using a plurality of flexures, the flexures being coupled at multiple points to an inner surface of the plurality of plunger segments such that a head of each flexure is configured to rotate about a pivot point located within a neighboring plunger segment; and sealing the gap by allowing rotation of at least some of the plurality of plunger segments about their respective pivot points, such that the plunger assembly contours against at least a portion of the movable surface when moving. ### Claim 16 (depends on 15) The method of claim 15, further comprising defining a predetermined distance between each of the plurality of plunger segments using the plurality of flexures. ### Claim 17 (depends on 16) The method of claim 16, wherein the predetermined distance is substantially uniform between each of the plurality of plunger segments. ### Claim 18 (depends on 15) The method of claim 15, wherein the plurality of flexures are coupled to the inner surface of the plurality of plunger segments using at least one of bonding, soldering, welding, braising, and adhesive methods. ### Claim 19 (depends on 15) The method of claim 15, wherein the plurality of plunger segments are fabricated using at least one of a machining process, a stamping process, a casting process, and an additive manufacturing process. ### Claim 20 (depends on 15) The method of claim 15, wherein the plunger seal apparatus is configured to operate in temperatures between 500 and 2000 degrees Fahrenheit.