# US 12,179,427 B2 · Techniques for releasing parts in additive fabrication and related systems and methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,179,427 B2 - Document ID: US12179427B2 - Status: Granted - Kind: B2 - Application number: 18/535,403 - Filed: 2023-12-11 - Published: 2024-05-30 - Granted: 2024-12-31 - Earliest claimed: 2021-06-25 - Assignees: Formlabs, Inc. - Applicants: Formlabs, Inc. - Inventors: Mark J. Frykman; Mark J. Ripoll; Lawrence Cheung; Nathan Jeffery; Yoav Reches; Derek J. Vilim - Web page: https://patentgrep.com/patent/US12179427B2 ## CPC - B29C 64/245: Platforms or substrates (support structures intended to be sacrificed after manufacture B29C64/40) - B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor - B33Y 40/00: Auxiliary operations or equipment, e.g. for material handling - 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 ## Abstract An improved additive fabrication device and a build platform are provided. The additive fabrication device is configured to form layers of material on a build surface. The additive fabrication device comprising: a build platform comprising: a rigid structure; an actuation structure attached to the rigid structure, wherein the actuation structure comprises one or more sheet handles and a flexible sheet, and wherein a first surface of the flexible sheet forms a build surface on which the additive fabrication device is configured to form layers of materials; and the one or more sheet handles are configured to be actuated to apply a force to the flexible sheet while at least a part of the actuation structure remains attached to the rigid structure, to deform at least a part of the flexible sheet away from the rigid structure. ## Claims ### Claim 1 A build platform for an additive fabrication device, the build platform comprising: a rigid structure; and an actuation structure coupled to the rigid structure, the actuation structure comprising a flexible sheet and two handles coupled to the flexible sheet, wherein a first surface of the flexible sheet provides a build surface on which the additive fabrication device is configured to form layers of material, and wherein the two handles are configured to be actuated by moving the two handles relative to one another, thereby causing at least part of the flexible sheet to deform away from the rigid structure. ### Claim 2 (depends on 1) The build platform of claim 1, further comprising one or more magnets that couple the actuation structure to the rigid structure. ### Claim 3 (depends on 2) The build platform of claim 2, wherein a second surface of the flexible sheet is configured to be coupled to a first surface of the rigid structure, and wherein the first surface of the rigid structure includes: a first magnetic zone exerting a first amount of magnetic force per area on the actuation structure, and a second magnetic zone exerting a second amount of magnetic force per area on the actuation structure; and wherein the first amount is different from the second amount. ### Claim 4 (depends on 1) The build platform of claim 1, wherein the two handles comprise a first handle attached to a first edge of the flexible sheet and a second handle attached to the flexible sheet at a second edge of the flexible sheet, the second edge opposing the first edge. ### Claim 5 (depends on 1) The build platform of claim 1, wherein the rigid structure includes a mounting device configured to be removably attached to the additive fabrication device. ### Claim 6 (depends on 1) The build platform of claim 1, wherein the two handles each comprises a drip-prevention structure to catch liquid that drips from the flexible sheet when the build platform is oriented with the flexible sheet above the two handles. ### Claim 7 (depends on 1) The build platform of claim 1, wherein the build platform is configured to be removed from the additive fabrication device and to be removably attached to a mount during said actuation of the two handles. ### Claim 8 (depends on 1) The build platform of claim 1, wherein the rigid structure includes one or more troughs at its edges, and wherein a part of each of the two handles rests in one of the one or more troughs. ### Claim 9 (depends on 2) The build platform of claim 2, wherein during actuation of the two handles to apply a force to the flexible sheet: during a first phase of the actuation, an elastic force experienced by a first part of the flexible sheet is smaller than a magnetic force exerted on the first part of the flexible sheet by the one or more magnets; during a second phase of the actuation, the elastic force experienced by the first part of the flexible sheet is greater than the magnetic force exerted on the first part of the flexible sheet by the one or more magnets. ### Claim 10 (depends on 1) The build platform of claim 1, wherein the two handles are configured to be actuated while at least a part of the actuation structure remains coupled to the rigid structure. ### Claim 11 (depends on 1) The build platform of claim 1, wherein the actuation structure is coupled to the rigid structure through mechanical retaining means. ### Claim 12 (depends on 1) The build platform of claim 1, wherein actuating the two handles by moving the two handles relative to one another comprises moving the two handles toward one another. ### Claim 13 A build platform for an additive fabrication device, the build platform comprising: a rigid structure formed from, or comprising, one or more magnets; and an actuation structure comprising a ferromagnetic flexible sheet and two handles coupled to the flexible sheet, wherein a first surface of the flexible sheet provides a build surface on which the additive fabrication device is configured to form layers of material, wherein, in a first configuration of the build platform, the flexible sheet is magnetically coupled to the rigid structure, and wherein the two handles are configured to be actuated by moving the two handles relative to one another, thereby producing a second configuration of the build platform in which at least part of the flexible sheet is deformed away from the rigid structure. ### Claim 14 (depends on 13) The build platform of claim 13, wherein the two handles comprise a first handle attached to a first edge of the flexible sheet and a second handle attached to the flexible sheet at a second edge of the flexible sheet, the second edge opposing the first edge. ### Claim 15 (depends on 13) The build platform of claim 13, wherein the rigid structure includes a mounting device configured to be removably attached to the additive fabrication device. ### Claim 16 (depends on 13) The build platform of claim 13, wherein the two handles each comprises a drip-prevention structure to catch liquid that drips from the flexible sheet when the build platform is oriented with the flexible sheet above the two handles. ### Claim 17 (depends on 13) The build platform of claim 13, wherein the rigid structure includes one or more troughs at its edges, and wherein a part of each of the two handles rests in one of the one or more troughs. ### Claim 18 (depends on 14) The build platform of claim 14, wherein actuating the two handles by moving the two handles relative to one another comprises moving the two handles toward one another. ### Claim 19 (depends on 13) The build platform of claim 13, wherein actuating the two handles applies a force to the flexible sheet. ### Claim 20 (depends on 19) The build platform of claim 19, wherein during actuation of the two handles: during a first phase of the actuation, an elastic force experienced by a first part of the flexible sheet is smaller than a magnetic force exerted on the first part of the flexible sheet by the one or more magnets; and during a second phase of the actuation, the elastic force experienced by the first part of the flexible sheet is greater than the magnetic force exerted on the first part of the flexible sheet by the one or more magnets.