# US 10,308,343 B2 · Composite hat stiffener > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,308,343 B2 - Document ID: US10308343B2 - Status: Granted - Kind: B2 - Application number: 13/905,294 - Filed: 2013-05-30 - Published: 2014-12-04 - Granted: 2019-06-04 - Earliest claimed: 2013-05-30 - Assignees: The Boeing Company - Applicants: The Boeing Company - Inventors: Jason Lawrence Firko; Christopher Mazza - Web page: https://patentgrep.com/patent/US10308343B2 ## CPC - B64C 1/12: Construction or attachment of skin panels - B29C 48/12: Articles with an irregular circumference when viewed in cross-section, e.g. window profiles - B29D 99/0014: {provided with ridges or ribs, e.g. joined ribs} - B64C 1/064: {Stringers; Longerons} - B64C 2001/0072: {from composite materials} - Y02T 50/40: Weight reduction - Y10T 428/24479: including variation in thickness - Y10T 428/24612: Composite web or sheet - B64C: AEROPLANES; HELICOPTERS - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A hat stiffener disclosed herein that includes a web portion having locally optimized slopes. The hat stiffener may include a web portion having a relatively small slope optimized to handle a sheer force. The hat stiffener may further include a web portion having a relatively large slope optimized to handle a pull-off or interface force. The hat stiffener may include a hat cap having variable widths along the length of the hat stiffener. The hat stiffener may further include a transitional web portion to transition from a web portion having a relatively large slope to a web portion having a relatively smaller slope. The concepts disclosed herein allow for the generation of a one-piece hat stiffener, which can be locally optimized to improve structural capability and efficiency for different loading applications. ## Claims ### Claim 1 A hat stiffener, comprising: a hat cap having a planar hat cap section along a linear portion of the hat cap; a plurality of hat flanges along the planar hat cap section, each of the plurality of hat flanges being planar; and a hat web extending between the planar hat cap section and a selected one of the plurality of hat flanges, the hat web including: a first planar web section at a first location along the planar hat cap section, the first planar web section extending from the planar hat cap section to the selected one of the plurality of hat flanges and having a first slope, and a second planar web section at a second location along the planar hat cap section, the second planar web section extending from the planar hat cap section to the selected one of the plurality of hat flanges and having a second slope, wherein the second slope is greater than the first slope such that the hat stiffener has a first internal width corresponding to the first slope and a second internal width corresponding to the second slope along the linear portion of the hat cap. ### Claim 2 (depends on 1) The hat stiffener of claim 1, wherein the first slope is configured to withstand a shear force. ### Claim 3 (depends on 1) The hat stiffener of claim 1, wherein the second slope is configured to withstand a pull-off force. ### Claim 4 (depends on 1) The hat stiffener of claim 1, wherein the hat web further comprises a transitional web section having a transitional slope that provides a transition from the first slope to the second slope. ### Claim 5 (depends on 1) The hat stiffener of claim 1, wherein the hat web further comprises a third planar web section at a third location along the planar hat cap section, the third planar web section extending from the planar hat cap section to the selected one of the plurality of hat flanges and having a third slope. ### Claim 6 (depends on 5) The hat stiffener of claim 5, wherein the third slope is the same as the first slope. ### Claim 7 (depends on 1) The hat stiffener of claim 1, wherein a width of the hat cap varies along the planar hat cap section. ### Claim 8 (depends on 7) The hat stiffener of claim 7, wherein the width of the hat cap corresponding to the second slope is greater than the width of the hat cap corresponding to the first slope. ### Claim 9 A composite structure, comprising: a composite skin; and a plurality of hat stiffeners affixed to the composite skin, each of the plurality of hat stiffeners comprising; a hat cap having a planar hat cap section along a linear portion of the hat cap, a plurality of hat flanges along the planar hat cap section, each of the plurality of flanges being planar, and a hat web extending between the planar hat cap section and a selected one of the plurality of flanges, the hat web including: a first planar web section at a first location along the planar hat cap section, the first planar web section extending from the planar hat cap section to the selected one of the plurality of hat flanges and having a first slope, and a second planar web section at a second location along the planar hat cap section, the second planar web section extending from the planar hat cap section to the selected one of the plurality of hat flanges and having a second slope, wherein the second slope is greater than the first slope such that the plurality of hat stiffeners has a first internal width corresponding to the first slope and a second internal width corresponding to the second slope along the linear portion of the hat cap. ### Claim 10 (depends on 9) The composite structure of claim 9, wherein the first slope is configured to withstand a shear force. ### Claim 11 (depends on 9) The composite structure of claim 9, wherein the second slope is configured to withstand a pull-off force. ### Claim 12 (depends on 9) The composite structure of claim 9, wherein the hat web further comprises a transitional web section having a transitional slope. ### Claim 13 (depends on 12) The composite structure of claim 12, wherein the transitional slope provides a transition from the first slope to the second slope. ### Claim 14 (depends on 9) The composite structure of claim 9, wherein the hat web further comprises a third planar web section at a third location along the planar hat cap section, the third planar web section extending from the planar hat cap section to the selected one of the plurality of hat flanges and having a third slope. ### Claim 15 (depends on 9) The composite structure of claim 9, wherein a width of the hat cap varies along the planar hat cap section. ### Claim 16 A hat stiffener, comprising: a hat cap having a central axis that is linear and having a planar hat cap section; a hat flange extending parallel to the hat cap along the planar hat cap section; and a hat web intersecting the planar hat cap section at a first end and intersecting the hat flange at a second end, the hat web including: a first planar web section at a first cross-section of the hat stiffener at a first position along the planar hat cap section, the first planar web section extending from the planar hat cap section to the hat flange and having a first slope corresponding to a first constant gradient of the hat web from the first end to the second end, and a second planar web section at a second cross-section of the hat stiffener at a second position along the planar hat cap section, the second planar web section extending from the planar hat cap section to the hat flange and having a second slope corresponding to a second constant gradient of the hat web from the first end to the second end, wherein the second slope is greater than the first slope. ### Claim 17 (depends on 16) The hat stiffener of claim 16, further comprising a third planar web section at a third cross-section of the hat stiffener at a third position along the planar hat cap section, the third planar web section extending from the planar hat cap section to the hat flange and having the first slope corresponding to the first constant gradient. ### Claim 18 (depends on 17) The hat stiffener of claim 17, further comprising: a first transitional web section between and abutting the first planar web section and the second planar web section, the first transitional web section having a first transitional slope that varies to provide a first transition from the first slope of the first planar web section to the second slope of the second planar web section; and a second transitional web section between and abutting the second planar web section and the third planar web section, the second transitional web section having a second transitional slope that varies to provide a second transition from the second slope of the second planar web section to the first slope of the third planar web section.