# US 2016/0252104 A1 · Fan blade composite segments > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0252104 A1 - Document ID: US20160252104A1 - Status: Published application - Kind: A1 - Application number: 15/032,900 - Filed: 2014-10-09 - Published: 2016-09-01 - Earliest claimed: 2013-10-30 - Assignees: United Technologies Corporation - Applicants: United Technologies Corporation - Inventors: Kwan Hui; Michael A. Weisse - Web page: https://patentgrep.com/patent/US20160252104A1 ## CPC - F04D 29/388: {characterised by construction} - F01D 5/147: {Construction, i.e. structural features, e.g. of weight-saving hollow blades (F01D5/148, F01D5/16 and F01D5/20 take precedence; blade shape F01D5/141; blades with cooling or heating channels or cavities F01D5/18; heating, heat-insulating or cooling means on blades F01D5/18)} - F01D 5/282: {Selecting composite materials, e.g. blades with reinforcing filaments} - F02K 3/06: with front fan - F04D 29/023: {especially adapted for elastic fluid pumps} - F04D 29/325: {for axial flow fans (blade mountings F04D29/34, blades F04D29/38)} - F05D 2220/36: specially adapted for the fan of turbofan engines - F05D 2300/133: Titanium - F05D 2300/603: Composites; e.g. fibre-reinforced - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - 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) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A fan blade includes a blade body, a composite segment and a cover. The blade body extends from a blade root to an opposed blade tip along a longitudinal axis. The blade body defines a leading edge and a trailing edge. A first airfoil surface extends from the leading edge to the trailing edge. A pocket is defined between the leading edge, the trailing edge, the blade root and the blade tip. The pocket has a bottom surface that opposes the first airfoil surface across the blade body. The composite segment is disposed in the pocket. The cover is mounted to the composite segment and to the blade body to form a second airfoil surface opposed to the first airfoil surface. ## Claims ### Claim 1 A fan blade, comprising: a blade body extending from a blade root to an opposed blade tip along a longitudinal axis, wherein the blade body defines a leading edge and a trailing edge, a first airfoil surface extending from the leading edge to the trailing edge, and a pocket defined between the leading edge, the trailing edge, the blade root and the blade tip, the pocket having a bottom surface that opposes the first airfoil surface across the blade body; a composite segment disposed in the pocket; and a cover mounted to the composite segment and to the blade body to form a second airfoil surface opposed to the first airfoil surface. ### Claim 2 (depends on 1) A fan blade as recited in claim 1, wherein the composite segment is adhered to the bottom surface of the pocket. ### Claim 3 (depends on 1) A fan blade as recited in claim 1, wherein the composite segment is adhered to the cover to resist forces acting on the cover in order to secure the cover to the blade body. ### Claim 4 (depends on 1) A fan blade as recited in claim 1, further comprising: a clearance defined between the composite segment and each of a leading edge side of the pocket and a trailing edge side of the pocket, wherein the clearance is configured to provide flexibility to the cover. ### Claim 5 (depends on 1) A fan blade as recited in claim 1, further comprising: a clearance defined between the composite segment and a pocket perimeter, wherein the clearance is configured to provide flexibility to the cover. ### Claim 6 (depends on 1) A fan blade as recited in claim 1, wherein the blade body includes a recessed lip defined around its perimeter. ### Claim 7 (depends on 6) A fan blade as recited in claim 6, wherein an interior surface of the cover is adhered to the blade body on the recessed lip, wherein the recessed lip is configured to allow the cover to be mounted flush with the blade body. ### Claim 8 (depends on 1) A fan blade as recited in claim 1, wherein the pocket of the blade body is at least partially filled with lightweight filler material. ### Claim 9 A fan blade, comprising: a blade body extending from a blade root to a blade tip along a longitudinal axis, wherein the blade body defines a leading edge and a trailing edge, a first airfoil surface extending from the leading edge to the trailing edge; a pocket defined between the leading edge, the trailing edge, the blade root and the blade tip; a plurality of composite segments disposed in the pocket; and a cover mounted to the composite segment and to the blade body to form a second airfoil surface. ### Claim 10 (depends on 9) A fan blade as recited in claim 9, further comprising: a clearance defined between the plurality of composite segments and each of a leading edge side of the pocket and a trailing edge side of the pocket, wherein the clearance is configured to provide flexibility to the cover. ### Claim 11 (depends on 9) A fan blade as recited in claim 9, further comprising: a clearance defined between the plurality of composite segments and a pocket perimeter, wherein the clearance is configured to provide flexibility to the cover. ### Claim 12 (depends on 9) A fan blade as recited in claim 9, further comprising: at least one clearance defined between each of the plurality of composite segments, wherein the clearance is configured to provide flexibility to the cover. ### Claim 13 (depends on 9) A fan blade as recited in claim 9, wherein the pocket has a bottom surface that opposes the airfoil surface across the blade body. ### Claim 14 (depends on 13) A fan blade as recited in claim 13, wherein the plurality of composite segments are adhered to the bottom surface of the pocket. ### Claim 15 (depends on 9) A fan blade as recited in claim 9, wherein the plurality of composite segments are adhered to the cover to resist forces acting on the cover in order to secure the cover to the blade body. ### Claim 16 (depends on 9) A fan blade as recited in claim 9, wherein the blade body includes a recessed lip defined around its perimeter. ### Claim 17 (depends on 9) A fan blade as recited in claim 9, wherein an interior surface of the cover is adhered to the blade body on the recessed lip, wherein the recessed lip is configured to allow the cover to be mounted flush with the blade body. ### Claim 18 (depends on 9) A fan blade as recited in claim 9, wherein the pocket of the blade body is at least partially filled with lightweight filler material.