# US 11,993,012 B2 · Apparatus and method for thermal compensation during additive manufacturing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,993,012 B2 - Document ID: US11993012B2 - Status: Granted - Kind: B2 - Application number: 17/375,725 - Filed: 2021-07-14 - Published: 2021-11-11 - Granted: 2024-05-28 - Earliest claimed: 2019-10-08 - Assignees: Thermwood Corporation - Applicants: Thermwood Corporation - Inventors: Kenneth J. Susnjara; Brian S. Smiddy; John Fuquay; Scott G. Vaal - Web page: https://patentgrep.com/patent/US11993012B2 ## CPC - B29C 64/209: Heads; Nozzles - B22F 10/18: by mixing binder with metal in filament form, e.g. fused filament fabrication [FFF] - B22F 12/53: Nozzles - B29C 64/118: using filamentary material being melted, e.g. fused deposition modelling [FDM] - B29C 64/205: Means for applying layers - B29C 64/227: Driving means - B29C 64/232: for motion along the axis orthogonal to the plane of a layer - B29C 64/25: Housings, e.g. machine housings - B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor - B33Y 10/00: Processes of additive manufacturing - Y02P 10/25: Process efficiency - 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) - B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER - B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract An additive manufacturing apparatus includes an extruder and a gear pump in fluid communication with extruder. The additive manufacturing apparatus also includes a nozzle in fluid communication with the gear pump. The extruder is connected to a guide member such that at least a portion of the extruder is configured to expand and move along the guide member according to a thermal expansion of the extruder. ## Claims ### Claim 1 An additive manufacturing apparatus, comprising: a print head including: an applicator head assembly including a housing and a nozzle, wherein the nozzle is configured to deposit a flowable material; an extruder in fluid communication with the nozzle; and a gear pump disposed between the applicator head assembly and the extruder; and a carrier movably disposed above a worktable, the carrier configured to move to control a position of the nozzle with respect to the worktable; wherein the print head is fixedly connected to the carrier at the gear pump, and wherein the extruder is movably connected to the carrier at a linear bearing of the carrier positioned above the gear pump such that at least a portion of the extruder is capable of moving in a first direction with respect to the carrier in accordance with a thermal expansion of the extruder and the applicator head assembly is capable of moving in a second direction in accordance with a thermal expansion of the applicator head assembly with respect to the carrier opposite the first direction. ### Claim 2 (depends on 1) The additive manufacturing apparatus of claim 1, wherein at least a portion of the extruder is configured to move away from the gear pump of the print head. ### Claim 3 (depends on 1) The additive manufacturing apparatus of claim 1, further including one or more rails extending along the carrier. ### Claim 4 (depends on 3) The additive manufacturing apparatus of claim 3, wherein the extruder is movably connected to at least one of the one or more rails via the linear bearing. ### Claim 5 (depends on 3) The additive manufacturing apparatus of claim 3, wherein the linear bearing is slidably connected to at least one of the one or more rails and connected to the extruder. ### Claim 6 (depends on 1) The additive manufacturing apparatus of claim 1, wherein the extruder is configured to increase in length in the first direction away from the gear pump of the print head due to thermal expansion of the extruder. ### Claim 7 (depends on 1) The additive manufacturing apparatus of claim 1, wherein the gear pump is in fluid communication with the extruder. ### Claim 8 (depends on 7) The additive manufacturing apparatus of claim 7, wherein the gear pump is in in fluid communication with the nozzle. ### Claim 9 (depends on 1) The additive manufacturing apparatus of claim 1, wherein the extruder is movably connected to the carrier at the linear bearing and at a support bearing. ### Claim 10 An additive manufacturing apparatus, comprising: a print head including a nozzle configured to deposit a flowable material; an extruder in fluid communication with the nozzle; a gear pump disposed between the nozzle and the extruder; a carrier movably disposed above a worktable, the carrier configured to move in at least a first dimension and a second dimension to control a position of the nozzle with respect to the worktable; and a lead screw configured to expand and to compensate for thermal expansion of the extruder, wherein the print head is fixedly connected to the carrier at the gear pump, wherein the extruder is movably connected to the carrier with the lead screw at a nut, the extruder being capable of moving in a first direction with respect to the carrier in accordance with a thermal expansion of the extruder, and wherein the nozzle is moveable in a second direction with respect to the carrier that is opposite the first direction. ### Claim 11 (depends on 10) The additive manufacturing apparatus of claim 10, wherein at least a portion of the extruder is configured to move away from the gear pump. ### Claim 12 (depends on 10) The additive manufacturing apparatus of claim 10, wherein the lead screw includes a reduced-diameter portion configured to facilitate movement of the lead screw to compensate for the thermal expansion of the extruder. ### Claim 13 (depends on 12) The additive manufacturing apparatus of claim 12, further including two rails extending along the carrier and a bearing connected to at least one of the rails and connected to the extruder. ### Claim 14 (depends on 10) The additive manufacturing apparatus of claim 10, wherein the extruder is configured to increase in length in the first direction away from the gear pump due to thermal expansion of the extruder. ### Claim 15 (depends on 10) The additive manufacturing apparatus of claim 10, wherein the gear pump is in in fluid communication with the nozzle. ### Claim 16 (depends on 10) The additive manufacturing apparatus of claim 10, wherein the carrier comprises a support bearing, wherein the lead screw is movable within the support bearing according to thermal expansion of the extruder and of the lead screw. ### Claim 17 An additive manufacturing apparatus, comprising: a print head including a nozzle configured to deposit a flowable material and an extruder in fluid communication with the nozzle; a carrier movably disposed above a worktable, the carrier configured to move in at least a first dimension and a second dimension to control a position of the nozzle with respect to the worktable; and a lead screw configured to expand and to compensate for thermal expansion of the extruder, wherein the print head is fixedly connected to the carrier at a fixed portion of the print head, the fixed portion being located between and adjacent to both the extruder and the nozzle, wherein a portion of the extruder opposite the nozzle is configured to move in a first direction with respect to the carrier due to thermal expansion of the extruder and the nozzle is configured to move in a second direction with respect to the carrier opposite the first direction, according to thermal expansion of the nozzle, the nozzle having a length that compensates for the thermal expansion of the nozzle, and wherein the extruder is configured to increase in length in the first direction away from the fixed portion of the print head. ### Claim 18 (depends on 17) The additive manufacturing apparatus of claim 17, further including one or more rails extending along the carrier and being substantially parallel to the extruder, wherein the extruder is slidably connected to at least one of the one or more rails. ### Claim 19 (depends on 17) The additive manufacturing apparatus of claim 17, wherein the nozzle includes a marking that corresponds to the length of the nozzle that compensates for thermal expansion of the nozzle. ### Claim 20 (depends on 18) The additive manufacturing apparatus of claim 18, wherein the extruder is movably connected to the carrier at a linear bearing of the carrier, and the linear bearing is movably connected to the at least one of the one or more rails.