# US 11,305,356 B2 · Building cylinders for machines for the layer-by-layer production of three-dimensional objects > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,305,356 B2 - Document ID: US11305356B2 - Status: Granted - Kind: B2 - Application number: 16/824,243 - Filed: 2020-03-19 - Published: 2020-07-09 - Granted: 2022-04-19 - Earliest claimed: 2017-09-20 - Assignees: TRUMPF Laser- und Systemtechnik GmbH - Applicants: Trumpf Laser—und Systemtechnik GmbH - Inventors: Markus Pieger - Web page: https://patentgrep.com/patent/US11305356B2 ## CPC - B22F 12/80: Plants, production lines or modules - B22F 10/28: Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] - B22F 12/13: to preheat the material - B22F 12/38: {Housings, e.g. machine housings} - B29C 64/153: using layers of powder being selectively joined, e.g. by selective laser sintering or melting - B29C 64/259: Interchangeable - B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor - B22F 10/32: of the atmosphere, e.g. composition or pressure in a building chamber - B22F 10/73: of powder - B22F 12/44: characterised by the configuration of the radiation means - B22F 2999/00: Aspects linked to processes or compositions used in powder metallurgy - B33Y 10/00: Processes of additive manufacturing - Y02P 10/25: Process efficiency - 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 - 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) - 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 Building cylinders, for use in machines for the layer-by-layer production of 3D objects by sintering or melting powdered material by a high-energy beam, and having a main body and a piston part movable on an inner side of the main body along a cylindrical axis, are disclosed. The piston part has a base element for the growth of a 3D object, and a powder seal bearing against the inner side of the main body for sealing the powdered material. The piston part has a seal carrier on which the powder seal is mounted, and an insulator, e.g., a circumferential insulation ring, mounted on the seal carrier. The base element is mounted on the insulator and is arranged at a distance from the seal carrier and from the powder seal. ## Claims ### Claim 1 A building cylinder arrangement for a machine for the layer-by-layer production of three-dimensional objects by sintering or melting powdered material by a high-energy beam, comprising: a) a building cylinder with a main body substantially in the form of a cylindrical casing and with an upper piston part movable on an inner side of the main body along a cylinder axis, wherein the upper piston part comprises, on its upper side, a base element in the form of a substrate or a preform, for the growth of a three-dimensional object, and further comprises a powder seal bearing against the inner side of the main body for sealing the powdered material; b) an intermediate piston part comprising a heater; c) a thermal insulation element, and d) a lower piston part comprising a gas seal, wherein the upper piston part, the intermediate piston part, the thermal insulation element, and the lower piston part together form a piston of the building cylinder arrangement, which piston is displaceable in the main body and can be connected and separated between the upper piston part and the intermediate piston part by a locking element, wherein the upper piston part has a seal carrier, on which the powder seal is mounted, wherein an insulation device is mounted on the seal carrier, and wherein the base element is mounted on the insulation device and is located at a distance from the seal carrier and from the powder seal. ### Claim 2 (depends on 1) The building cylinder arrangement of claim 1, wherein the thermal insulation element comprises a ceramic insulation plate. ### Claim 3 (depends on 1) The building cylinder arrangement of claim 1, wherein the insulation device comprises a circumferential insulation ring. ### Claim 4 (depends on 1) The building cylinder arrangement of claim 1, wherein the gas seal comprises an elastomer material. ### Claim 5 (depends on 1) The building cylinder arrangement of claim 1, wherein the seal carrier has a lower seal carrier ring and an upper seal carrier ring, which are mounted on top of one another and together form an external guide in which the powder seal is laid. ### Claim 6 (depends on 5) The building cylinder arrangement of claim 5, wherein the external guide comprises an external circumferential groove. ### Claim 7 (depends on 1) The building cylinder arrangement of claim 1, wherein a mutual contact profile of the base element and the thermal insulator has a sub-portion extending counter to gravity in the progression from outside to inside, and wherein a mutual contact profile of the seal carrier and the insulator also has a sub-portion extending counter to gravity in the progression from outside to inside. ### Claim 8 (depends on 1) The building cylinder arrangement of claim 1, wherein on the outside of the main body a circumferential carrier ring is arranged in which, distributed on the internal circumference, a plurality of radially outwardly directed recesses for bearing bolts are formed, in the main body, distributed on the external circumference of the main body, a plurality of radially inwardly directed depressions for bearing bolts are formed, a plurality of bearing bolts are provided, each bearing bolt penetrating into a recess and into a depression opposite the recess, and an internal diameter of the carrier ring is greater than an external diameter of the main body, and each bearing bolt is mounted in the recess and depression thereof with play in the longitudinal direction. ### Claim 9 (depends on 5) The building cylinder arrangement of claim 5, wherein a length L of each bearing bolt is greater than the sum of a depth TV of the associated depression and a depth TA of the associated recess. ### Claim 10 (depends on 5) The building cylinder arrangement of claim 5, wherein the carrier ring is formed with an upper carrier ring part and a lower carrier ring part, which are mounted on top of one another and together form the recesses. ### Claim 11 (depends on 1) The building cylinder arrangement of claim 1, wherein a control ring is mounted rotatably about the cylinder axis on the lower end of the main body, the control ring has external teeth, on the control ring, distributed in the circumferential direction, a plurality of control curve recesses are formed, wherein the radial position of the control curve recesses change as they progress in the circumferential direction, a plurality of support bolts are mounted radially displaceably on the lower end of the main body, distributed in the circumferential direction, the support bolts each have an axially projecting tappet that engages a control curve recess of the control ring, and by rotating the control ring, the support bolts can be displaced between a radially inwardly extended position, in which the upper piston part can lie on the support bolts, and a retracted position, in which the upper piston part can pass the support bolts. ### Claim 12 (depends on 11) The building cylinder arrangement of claim 11, wherein at least one spring is provided, by which the control ring is biased into a rotational position in which the support bolts are in the radially inwardly extended position. ### Claim 13 (depends on 1) The building cylinder arrangement of claim 1, wherein the building cylinder has a cover for sealing the building cylinder at an upper side, a circumferential seal is arranged between a cover-side support portion and a main-body-side support portion when the cover is placed on, and the cover-side support portion and the main-body-side support portion are formed such that when the cover is placed on there is a substantially linear force input into the seal. ### Claim 14 (depends on 13) The building cylinder arrangement of claim 13, wherein in the longitudinal section along the cylinder axis, a radius of curvature (KD) of the cover-side support portion and a radius of curvature (KG) of the main-body-side support portion have a different sign and differ in magnitude in a region of the linear force input, and wherein the cover-side support portion is formed with a convex curvature with a larger magnitude of the radius of curvature (KD) and the main-body-side support portion is formed with a concave curvature with a smaller magnitude of the radius of curvature (KG). ### Claim 15 (depends on 13) The building cylinder arrangement of claim 13, wherein the seal is fastened laterally on the cover, and wherein the cover, at least in a radial edge region, is formed with an upper cover part and a lower cover part that are mounted on top of one another and between which a part of the seal is clamped. ### Claim 16 (depends on 13) The building cylinder arrangement of claim 13, wherein the circumferential seal comprises a sealing film. ### Claim 17 (depends on 16) The building cylinder arrangement of claim 16, wherein the sealing film comprises graphite. ### Claim 18 (depends on 13) The building cylinder arrangement of claim 13, wherein at the upper end facing the cover, the main body forms a contour that narrows radially in the axially inward direction, and/or at the lower face facing the main body, the cover has a contour that tapers radially in the axially outward direction. ### Claim 19 (depends on 1) The building cylinder arrangement of claim 1, wherein the lower piston part is formed with an active cooling element. ### Claim 20 (depends on 1) The building cylinder arrangement of claim 1, wherein the thermal insulation element is arranged between the intermediate piston part and the lower piston part. ### Claim 21 (depends on 1) A machine for layer-by-layer production of three-dimensional objects by sintering or melting powdered material by a high-energy beam, comprising: a process chamber comprising a powder cylinder connector for a powder cylinder, a building cylinder connector for a building cylinder, and a slider for applying a layer of the powdered material in the building cylinder; at least one powder cylinder for the powdered material, comprising a powder piston that is movable in the powder cylinder; at least one building cylinder arrangement of claim 1; a high-energy beam source; a scanner for the high-energy beam; a first lifting device for the powder piston of a powder cylinder mounted on the powder cylinder connector; and a second lifting device for the upper piston part of a building cylinder mounted on the building cylinder connector. ### Claim 22 (depends on 21) The machine of claim 21, wherein in the second lifting device, the intermediate piston part comprises the heater for the base element of a locked upper piston part, the lower piston part comprises a cooling element, the thermal insulation element is arranged between the intermediate piston part and the lower piston part, and the intermediate part is displaceable, for the building process, together with the locked upper piston part and the lower piston part in the main body of a building cylinder connected to the building cylinder connector. ### Claim 23 (depends on 21) A system comprising a machine of claim 21; a plurality of building cylinders; and at least one floor conveyor, by which a building cylinder can be brought to or away from the machine; wherein the floor conveyor comprises a fork for engaging a carrier ring of a building cylinder from below, and wherein the floor conveyor comprises a gripper by which a cover of the building cylinder can be held down.