# US 8,783,078 B2 · Method to improve geometrical accuracy of an incrementally formed workpiece > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,783,078 B2 - Document ID: US8783078B2 - Status: Granted - Kind: B2 - Application number: 12/843,990 - Filed: 2010-07-27 - Published: 2012-02-02 - Granted: 2014-07-22 - Earliest claimed: 2010-07-27 - Assignees: Ford Global Technologies, LLC - Applicants: Feng Ren; Zhiyong Cedric Xia - Inventors: Feng Ren; Zhiyong Cedric Xia - Web page: https://patentgrep.com/patent/US8783078B2 ## CPC - B21D 5/01: between rams and anvils or abutments - B21D 31/00: Other methods for working sheet metal, metal tubes, metal profiles (deforming one surface of tubes helically by rolling B21H3/00; upsetting B21J5/08; working metal by removing material therefrom B23; embossing B44B) - B21D 31/005: {Incremental shaping or bending, e.g. stepwise moving a shaping tool along the surface of the workpiece (B21D22/14 takes precedence)} - B21D: WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL (working or processing of wire B21F) ## Abstract A method of incrementally forming a workpiece. The method may include incrementally forming a stiffening feature on the workpiece and incrementally forming a part on the workpiece. A gap between forming tools may be decreased to reform the part. ## Claims ### Claim 1 A method of incrementally forming a workpiece, comprising: incrementally forming a stiffening feature on the workpiece; and incrementally forming a part on the workpiece within the stiffening feature after completely incrementally forming the stiffening feature; wherein first and second tools move along multiple axes along opposite sides of the workpiece and do not penetrate the workpiece to incrementally form the stiffening feature and the part. ### Claim 2 (depends on 1) The method of claim 1 wherein the stiffening feature is spaced apart from a fixture assembly that supports the workpiece. ### Claim 3 (depends on 1) The method of claim 1 wherein the stiffening feature is configured as a ring and the workpiece is not incrementally formed between the stiffening feature and the part. ### Claim 4 (depends on 1) The method of claim 1 wherein the stiffening feature is incrementally formed at a faster tool feed rate than the part. ### Claim 5 (depends on 1) The method of claim 1 wherein the stiffening feature is formed in a first axial direction with respect to a fixture assembly that supports the workpiece. ### Claim 6 (depends on 1) The method of claim 1 wherein the stiffening feature includes a plurality of sides that are tapered toward the part. ### Claim 7 (depends on 1) The method of claim 1 wherein the stiffening feature includes a plurality of sides that each includes an area of curvature. ### Claim 8 (depends on 1) The method of claim 1 wherein the stiffening feature is generally formed in a first direction with respect to a reference plane. ### Claim 9 (depends on 1) The method of claim 1 wherein the stiffening feature is formed in a same axial direction as a majority of incrementally formed features of the part. ### Claim 10 (depends on 1) The method of claim 1 wherein the stiffening feature is a ring that completely surrounds a part forming area that is not incrementally formed, wherein the part is incrementally formed in the part forming area such that the part is completely separated from the stiffening feature. ### Claim 11 (depends on 1) The method of claim 1 wherein the part is incrementally formed by moving the first and second forming tools along the tool path from a start position to an end position and the part is reformed by moving the first and second forming tools along the tool path from the end position to the start position. ### Claim 12 (depends on 1) The method of claim 1 wherein the part is incrementally formed by moving the first and second forming tools along a first spiral tool path from a start position to an end position and the part is reformed by moving the forming tools along a second spiral tool path from the end position to the start position. ### Claim 13 (depends on 12) The method of claim 12 wherein the first spiral tool path differs from the second spiral tool path. ### Claim 14 A method of incrementally forming a workpiece, comprising: incrementally forming a stiffening feature on the workpiece; and incrementally forming a part on the workpiece outwardly from the stiffening feature after incrementally forming the stiffening feature; wherein first and second tools move along multiple axes along opposite sides of the workpiece to incrementally form the stiffening feature and the part. ### Claim 15 (depends on 14) The method of claim 14 wherein the stiffening feature is incrementally formed at a faster tool feed rate than the part. ### Claim 16 (depends on 14) The method of claim 14 wherein incrementally forming the part includes reforming the stiffening feature to improve surface finish of the stiffening feature. ### Claim 17 (depends on 14) The method of claim 14 wherein the stiffening feature is contiguous with at least a portion of the part. ### Claim 18 (depends on 14) The method of claim 14 wherein the first and second tools do not penetrate the workpiece when the stiffening feature and part are incrementally formed. ### Claim 19 (depends on 14) The method of claim 14 wherein the workpiece is not incrementally formed between the stiffening feature and the part. ### Claim 20 (depends on 14) The method of claim 14 wherein the part is incrementally formed by moving the first and second forming tools along the tool path from a start position to an end position and the part is reformed by moving the first and second forming tools along the tool path from the end position to the start position.