# US 12,005,638 B2 · Additive manufacturing gas extraction > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,005,638 B2 - Document ID: US12005638B2 - Status: Granted - Kind: B2 - Application number: 17/051,711 - Filed: 2018-10-18 - Published: 2021-04-29 - Granted: 2024-06-11 - Earliest claimed: 2018-10-18 - Assignees: Hewlett-Packard Development Company, L.P. - Applicants: Hewlett-Packard Development Company, L.P. - Inventors: Ignacio Alejandre Fernandez; Emilio Cano Arribas; Cintia Perez Gutierrez - Web page: https://patentgrep.com/patent/US12005638B2 ## CPC - B29C 64/153: using layers of powder being selectively joined, e.g. by selective laser sintering or melting - B22F 10/20: Direct sintering or melting - B22F 10/32: of the atmosphere, e.g. composition or pressure in a building chamber - B22F 12/70: Gas flow means - B22F 12/90: Means for process control, e.g. cameras or sensors - B29C 64/371: using an environment other than air, e.g. inert gas - B29C 64/393: for controlling or regulating additive manufacturing processes - B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor - B22F 2999/00: Aspects linked to processes or compositions used in powder metallurgy - B33Y 10/00: Processes of additive manufacturing - B33Y 40/00: Auxiliary operations or equipment, e.g. for material handling - B33Y 70/00: Materials specially adapted for 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 example additive manufacturing system comprises a first fan associated with a print chamber to flow gas from the print chamber into an exhaust conduit. A sensor is arranged to detect one or more conditions of the gas flowed into the exhaust conduit from the print chamber by the first fan and to output a signal indicative thereof. A second fan is spaced apart in a downstream direction along the exhaust conduit from the first fan and a control unit is arranged to receive the signal from the sensor and to control the second fan in dependence thereon to maintain one or more conditions of the gas extracted from the print chamber. ## Claims ### Claim 1 An additive manufacturing system, comprising: a first fan to at least assist in flowing gas from a print chamber into an exhaust conduit to maintain one or more gas conditions within the print chamber; a sensor to detect one or more conditions of the gas in the exhaust conduit and to output an exhaust condition signal indicative thereof; a second fan spaced apart along the exhaust conduit from the first fan; a control unit arranged to control the second fan in dependence on the exhaust condition signal to maintain one or more conditions of the gas within the exhaust conduit, thereby assisting the first fan in maintaining the one or more gas conditions within the print chamber. ### Claim 2 (depends on 1) The additive manufacturing system of claim 1, wherein the sensor comprises at least one gas pressure sensor arranged to detect a pressure of the gas within the exhaust conduit, and to output the exhaust condition signal indicative thereof, and the control unit is arranged to control the second fan to maintain a predetermined pressure of gas within the exhaust conduit. ### Claim 3 (depends on 1) The additive manufacturing system of claim 1, wherein the sensor comprises at least one gas flow sensor arranged to detect a flow rate of the gas within the exhaust conduit and to output the exhaust condition signal indicative thereof, and the control unit is arranged to control the second fan to maintain a predetermined flow of gas within the exhaust conduit. ### Claim 4 (depends on 1) The additive manufacturing system of claim 1, wherein the sensor is arranged to detect one or more conditions of the gas within the exhaust conduit proximal to an outlet of the first fan. ### Claim 5 (depends on 1) The additive manufacturing system of claim 1, wherein the second fan is associated with a manifold of the exhaust conduit. ### Claim 6 (depends on 1) The additive manufacturing system of claim 1, wherein the second fan comprises a plurality of second fans. ### Claim 7 (depends on 6) The additive manufacturing system of claim 6, wherein: the first fan comprises a plurality of fans arranged to each extract gas from respective regions of the print chamber; at least some of the second fans are arranged to at least assist in flowing gas exhausted from a first region of the print chamber and at least some of the second fans are arranged to flow gas exhausted from a second region of the print chamber. ### Claim 8 (depends on 1) The additive manufacturing system of claim 1, wherein the exhaust conduit comprises a cooling volume interposing the first and second fans. ### Claim 9 (depends on 1) The additive manufacturing system of claim 1, comprising: a sensor to detect one or more conditions of the gas in the print chamber and to output a print chamber condition signal indicative thereof; wherein the control unit is arranged to control the second fan in dependence on the print chamber condition signal. ### Claim 10 (depends on 1) The additive manufacturing system of claim 1, wherein the control unit is arranged to control a speed of the second fan to maintain the one or more conditions of the gas extracted from the print chamber within the exhaust conduit. ### Claim 11 (depends on 1) The additive manufacturing system of claim 1, wherein the control unit is arranged to control a speed of the second fan to maintain the one or more conditions of the gas within the exhaust conduit between the first and second fans. ### Claim 12 (depends on 6) The additive manufacturing system of claim 6, wherein the plurality of second fans comprises a plurality of fans arranged in parallel. ### Claim 13 Machine executable instructions stored on a non-transitory machine-readable medium, the instructions being executable by a controller of an additive manufacturing system having a first fan associated with a print chamber to maintain one or more conditions in the print chamber by at least assisting flowing air from the print chamber into an exhaust conduit, a sensor to detect one or more conditions of the gas in the exhaust conduit and to output a signal indicative thereof, a second fan spaced apart along the exhaust conduit from the first fan, the machine executable instructions comprising instructions to control the second fan in dependence on the one or more conditions of the gas in the exhaust conduit thereby assisting the first fan in maintain the one or more conditions in the print chamber. ### Claim 14 (depends on 13) The additive manufacturing system of claim 13, wherein the sensor comprises a pressure sensor arranged to detect a pressure of the gas within the exhaust conduit and the machine executable instructions comprise instructions to control the second fan to maintain a predetermined pressure of gas within the exhaust conduit. ### Claim 15 (depends on 13) The additive manufacturing system of claim 13, wherein the sensor comprises a gas flow sensor arranged to detect a flow rate of gas within the exhaust conduit and the machine executable instructions comprising instructions to control the second fan to maintain a predetermined flow of gas within the exhaust conduit.