Prior art — US Patent 9421713B2

Here is an analysis of the prior art cited in US Patent 9421713B2, focusing on potential anticipation under 35 U.S.C. § 102.

The core innovation of US9421713B2 resides in the method of performing a purge operation by printing a layer of at least one purge tower directly on the build platform during material switching in multi-head additive manufacturing systems, thereby eliminating the need for a separate purge station. For a piece of prior art to anticipate a claim under 35 U.S.C. § 102, every element of that claim must be disclosed, either explicitly or inherently, in a single reference.

Cited Prior Art References and Anticipation Analysis:

US 2010/0283172 A1 (Swanson et al.)
- Full Citation: Swanson et al., U.S. Patent Application Publication No. 2010/0283172 A1, titled "Print heads and material dispensing systems and methods."
- Publication Date: November 11, 2010.
- Brief Description: This publication describes print heads for extrusion-based additive manufacturing systems, particularly focusing on systems with multiple print heads for dispensing different materials (build and support). It covers mechanisms for moving these print heads and selectively heating/cooling liquefier assemblies to switch between operating and stand-by modes.
- Potential Anticipation: This reference anticipates elements of the preamble of claim 1 regarding "multiple print heads or deposition lines using a layer-based, additive manufacturing technique." It also anticipates the "switching the print heads... between stand-by modes and operating modes in-between the printing of the layers" as described in claim 1, and the specific configurations of claims 2 and 3 concerning switching between a first and second print head/deposition line. However, it does not disclose the step of "printing at least one purge tower" as part of a purge operation.
US 2012/0164256 A1 (Swanson et al.)
- Full Citation: Swanson et al., U.S. Patent Application Publication No. 2012/0164256 A1, titled "Multi-nozzle print heads and multi-material dispensing systems and methods."
- Publication Date: June 28, 2012.
- Brief Description: This publication, a continuation-in-part of US2010/0283172A1, further details multi-nozzle print heads and multi-material dispensing systems, including selective heating/cooling of nozzles and mechanisms for positioning and retracting print heads to manage material flow and prevent oozing when idle.
- Potential Anticipation: Similar to US2010/0283172A1, it anticipates elements of claim 1 regarding "multiple print heads or deposition lines" and the "switching... between stand-by modes and operating modes" (relevant to claims 1, 2, and 3). It does not, however, teach the "printing at least one purge tower" for purge operations.
US 7,625,200 B2 (Leavitt)
- Full Citation: Leavitt, U.S. Patent No. 7,625,200 B2, titled "Apparatus and method for fabricating three-dimensional objects."
- Publication Date: December 1, 2009.
- Brief Description: This patent describes a system for fabricating 3D objects using a single deposition head with multiple deposition lines (nozzles) for different materials (build and support). It includes mechanisms for selectively activating/deactivating nozzles and moving the print head to prevent interference.
- Potential Anticipation: This reference is particularly relevant to the aspect of "multiple print heads or deposition lines" (claim 1) where a single head has multiple deposition lines, as discussed in US9421713B2. It anticipates the "switching... between stand-by modes and operating modes" (claims 1, 2, 3). It does not, however, disclose the "printing at least one purge tower" as the purge operation.
US 7,604,470 B2 (LaBossiere et al.)
- Full Citation: LaBossiere et al., U.S. Patent No. 7,604,470 B2, titled "Apparatus and method for fabricating three-dimensional objects."
- Publication Date: October 20, 2009.
- Brief Description: This patent discloses a fabrication system employing multiple extruders (print heads) for different materials. It details methods for controlling these extruders, including heating and cooling them, and retracting them when not in use to prevent material oozing.
- Potential Anticipation: This reference anticipates elements of claim 1 related to "multiple print heads" and the "switching... between stand-by modes and operating modes" (claims 1, 2, 3), particularly concerning distinct print heads. It does not teach the "printing at least one purge tower" as the purge operation.
US 7,744,364 B2 (Turley et al.)
- Full Citation: Turley et al., U.S. Patent No. 7,744,364 B2, titled "Extrusion-based three-dimensional printing systems with waste material containers."
- Publication Date: June 29, 2010.
- Brief Description: This patent describes conventional purge operations in extrusion-based 3D printing systems. It details the process of moving a print head to a dedicated "purge station" and extruding waste material into a "purge bucket," often followed by a tip wipe operation.
- Potential Anticipation: This reference is highly relevant as it explicitly teaches "performing a purge operation for each print head or deposition line switched to the operating mode" (part of claim 1). However, it describes this purge operation as using a "purge station" and "purge bucket," which directly contrasts with the "printing at least one purge tower" element of claim 1. Therefore, it anticipates the general concept of performing a purge operation but not the specific method of using a purge tower.
US 5,503,785 A (Crump et al.)
- Full Citation: Crump et al., U.S. Patent No. 5,503,785 A, titled "Apparatus and method for creating three-dimensional objects."
- Publication Date: April 2, 1996.
- Brief Description: This is a foundational patent for Fused Deposition Modeling (FDM), describing the basic principles of layer-by-layer additive manufacturing using thermoplastic materials for both model and support structures.
- Potential Anticipation: This patent broadly anticipates the preamble of claim 1, specifically "printing layers of the three-dimensional part and of a support structure... using a layer-based, additive manufacturing technique." It does not, however, address multi-head systems, switching between modes, or purge operations involving a purge tower.
US 6,070,107 A (Lombardi et al.)
- Full Citation: Lombardi et al., U.S. Patent No. 6,070,107 A, titled "Material handling system for a rapid prototyping apparatus."
- Publication Date: May 30, 2000.
- Brief Description: This patent focuses on systems for handling and feeding different build materials in an FDM system, particularly material cartridges and feeding mechanisms.
- Potential Anticipation: While it relates to multi-material printing, it does not anticipate any of the specific method steps of claim 1 concerning switching print heads or printing a purge tower.
US 6,228,923 B1 (Lombardi et al.)
- Full Citation: Lombardi et al., U.S. Patent No. 6,228,923 B1, titled "Material handling system for a rapid prototyping apparatus."
- Publication Date: May 8, 2001.
- Brief Description: A continuation of US6070107, this patent also describes material handling systems for rapid prototyping, including aspects of material cartridges and feeding.
- Potential Anticipation: Similar to US6070107, it does not anticipate the specific method steps of claim 1.
US 6,790,403 B1 (Priedeman et al.)
- Full Citation: Priedeman et al., U.S. Patent No. 6,790,403 B1, titled "System and method for building three-dimensional objects."
- Publication Date: September 14, 2004.
- Brief Description: This patent describes a general FDM system, including a build chamber and a platen, and methods for building 3D objects.
- Potential Anticipation: Broadly relevant to the overall system (e.g., build platform, chamber) described in US9421713B2 but does not anticipate the specific method claims.
US 7,122,246 B2 (Comb et al.)
- Full Citation: Comb et al., U.S. Patent No. 7,122,246 B2, titled "Build materials and support materials for use in fused deposition modeling."
- Publication Date: October 17, 2006.
- Brief Description: This patent focuses on specific material compositions suitable for FDM, including both build and support materials.
- Potential Anticipation: This reference is relevant to the "part material" and "support material" context of claim 1 but does not anticipate any of the method steps related to purge operations.
US 2009/0263582 A1 (Batchelder)
- Full Citation: Batchelder, U.S. Patent Application Publication No. 2009/0263582 A1, titled "Soluble support materials for use in fused deposition modeling systems."
- Publication Date: October 22, 2009.
- Brief Description: This publication describes soluble support material compositions for FDM, focusing on ease of removal.
- Potential Anticipation: Similar to US7122246, it concerns material compositions and not the purge tower method.
US 2010/0096072 A1 (Hopkins et al.)
- Full Citation: Hopkins et al., U.S. Patent Application Publication No. 2010/0096072 A1, titled "Support material structures for use in fused deposition modeling systems."
- Publication Date: April 22, 2010.
- Brief Description: This publication concerns the design and generation of support material structures to optimize printing and removal processes in FDM.
- Potential Anticipation: Relates to the general concept of a "support structure" (claim 1 preamble) but does not teach the purge tower method.
US 2011/0076496 A1 (Batchelder et al.)
- Full Citation: Batchelder et al., U.S. Patent Application Publication No. 2011/0076496 A1, titled "Consumable cartridges for three-dimensional modeling systems."
- Publication Date: March 31, 2011.
- Brief Description: This publication describes consumable material cartridges for FDM systems, including features for material feeding and identification.
- Potential Anticipation: Relates to consumable material handling, not the purge tower method.
US 2011/0076495 A1 (Batchelder et al.)
- Full Citation: Batchelder et al., U.S. Patent Application Publication No. 2011/0076495 A1, titled "Material cartridges for three-dimensional modeling systems with internal drive mechanisms."
- Publication Date: March 31, 2011.
- Brief Description: This publication further details material cartridges for 3D modeling systems, specifically those with integrated drive mechanisms.
- Potential Anticipation: Relates to consumable material handling, not the purge tower method.
US 7,127,309 B2 (Dunn et al.)
- Full Citation: Dunn et al., U.S. Patent No. 7,127,309 B2, titled "Support structure for use in a rapid prototyping machine."
- Publication Date: October 24, 2006.
- Brief Description: This patent describes a removable tray substrate used as a build platform to facilitate the removal of printed parts and support structures.
- Potential Anticipation: Relates to the "build substrate" mentioned in US9421713B2 but does not anticipate the purge tower method.
US 6,004,124 A (Swanson et al.)
- Full Citation: Swanson et al., U.S. Patent No. 6,004,124 A, titled "Temperature-controlled extrusion head for producing three-dimensional objects."
- Publication Date: December 21, 1999.
- Brief Description: This patent describes a temperature-controlled extrusion head for FDM systems, including heating and cooling elements to regulate material flow and prevent oozing when the head is idle.
- Potential Anticipation: This reference anticipates elements related to print head functionality and the control of operating/stand-by modes (claims 1, 2, 3), particularly the thermal management aspects to prevent oozing. It does not teach the purge tower method.
US 7,384,255 B2 (LaBossiere et al.)
- Full Citation: LaBossiere et al., U.S. Patent No. 7,384,255 B2, titled "Extrusion head with heated nozzle assembly."
- Publication Date: June 10, 2008.
- Brief Description: This patent describes an extrusion head with a heated nozzle assembly for FDM systems, focusing on maintaining consistent material temperature for extrusion.
- Potential Anticipation: Similar to US6004124, it contributes to the understanding of print head operation and temperature control (claims 1, 2, 3) but does not disclose the purge tower method.
US 7,896,209 B2 (Batchelder et al.)
- Full Citation: Batchelder et al., U.S. Patent No. 7,896,209 B2, titled "Nozzle tip wipe mechanism for extrusion-based digital manufacturing systems."
- Publication Date: March 1, 2011.
- Brief Description: This patent describes a dedicated mechanism for wiping excess material (ooze) from the extrusion nozzle tip, typically performed after a purge operation.
- Potential Anticipation: While it does not teach a purge tower, it anticipates the need for a tip wipe operation, which the purge tower in US9421713B2 can optionally provide (as described in the instant patent). It defines a problem that the purge tower can help solve, but does not anticipate the solution itself.
US 8,153,182 B2 (Comb et al.)
- Full Citation: Comb et al., U.S. Patent No. 8,153,182 B2, titled "Automated three-dimensional object fabrication system."
- Publication Date: April 10, 2012.
- Brief Description: This patent describes an automated 3D fabrication system, including aspects of material handling, build envelope, and overall system automation.
- Potential Anticipation: Relevant to the broader goal of automation and "printer farms" mentioned in US9421713B2, but it does not anticipate the specific purge tower method.
US 2012/0074619 A1 (Comb et al.)
- Full Citation: Comb et al., U.S. Patent Application Publication No. 2012/0074619 A1, titled "Gantry assemblies for additive manufacturing systems."
- Publication Date: March 29, 2012.
- Brief Description: This publication describes improved gantry assemblies for moving print heads in additive manufacturing systems, focusing on precision and reliability.
- Potential Anticipation: Relates to the mechanical movement of the print head (head gantry 38) as part of the system but does not anticipate the purge tower method.
US 2013/0056903 A1 (Swanson et al.)
- Full Citation: Swanson et al., U.S. Patent Application Publication No. 2013/0056903 A1, titled "Multi-nozzle print heads with multiple axial channels for additive manufacturing."
- Publication Date: March 7, 2013.
- Brief Description: This publication describes multi-nozzle print heads with multiple axial channels, with a focus on optimizing flow resistance and extrusion characteristics.
- Potential Anticipation: Contributes to the technical details of the print head nozzles (nozzle 18e) but does not anticipate the purge tower method.
US 2013/0056904 A1 (Crump et al.)
- Full Citation: Crump et al., U.S. Patent Application Publication No. 2013/0056904 A1, titled "Scaffolding for continuous-build additive manufacturing systems."
- Publication Date: March 7, 2013.
- Brief Description: This publication describes scaffolding systems designed to enable continuous building of multiple 3D parts, which is relevant to "printer farms" and automation.
- Potential Anticipation: Relates to the broader context of continuous manufacturing, where purge towers could be used, but it does not teach the purge tower method itself.
US 2013/0059012 A1 (Swanson et al.)
- Full Citation: Swanson et al., U.S. Patent Application Publication No. 2013/0059012 A1, titled "Continuous-build additive manufacturing systems."
- Publication Date: March 7, 2013.
- Brief Description: This publication describes systems and methods for continuous manufacturing of 3D objects, supporting high-volume, automated production environments.
- Potential Anticipation: Similar to US20130056904A1, it provides context for continuous manufacturing but does not anticipate the purge tower method.
US 2013/0059013 A1 (Mannella)
- Full Citation: Mannella, U.S. Patent Application Publication No. 2013/0059013 A1, titled "Continuous-build additive manufacturing systems with replaceable build substrates."
- Publication Date: March 7, 2013.
- Brief Description: This publication focuses on continuous-build systems that use replaceable build substrates to facilitate automated production workflows.
- Potential Anticipation: Also relates to continuous manufacturing and automation, without disclosing the purge tower method.
US 2013/0155209 A1 (Mannella et al.)
- Full Citation: Mannella et al., U.S. Patent Application Publication No. 2013/0155209 A1, titled "Consumable assemblies for additive manufacturing systems."
- Publication Date: June 20, 2013.
- Brief Description: This publication describes various consumable material assemblies (cartridges) with specific features for material retention and feeding within additive manufacturing systems.
- Potential Anticipation: Concerns material handling hardware (consumable assemblies 12) but does not anticipate the method of purging using a tower.
US 2013/0155210 A1 (Mannella et al.)
- Full Citation: Mannella et al., U.S. Patent Application Publication No. 2013/0155210 A1, titled "Material handling for additive manufacturing systems."
- Publication Date: June 20, 2013.
- Brief Description: This publication describes systems for handling and feeding consumable materials to additive manufacturing systems.
- Potential Anticipation: Similar to US20130155209A1, it relates to material handling, not the purge tower method.
US 2011/0117268 A1 (Batchelder et al.)
- Full Citation: Batchelder et al., U.S. Patent Application Publication No. 2011/0117268 A1, titled "Material authentication for three-dimensional modeling systems."
- Publication Date: May 19, 2011.
- Brief Description: This publication describes systems and methods for authenticating consumable materials used in 3D modeling systems, often via encoded markings.
- Potential Anticipation: Relates to material tracking and control, not the purge tower method.
US 2011/0121476 A1 (Batchelder et al.)
- Full Citation: Batchelder et al., U.S. Patent Application Publication No. 2011/0121476 A1, titled "Material recognition for three-dimensional modeling systems."
- Publication Date: May 26, 2011.
- Brief Description: This publication describes methods and systems for recognizing consumable materials in 3D modeling systems, often using RFID or other identifiers.
- Potential Anticipation: Relates to material tracking and control, not the purge tower method.
US 2011/0233804 A1 (Batchelder et al.)
- Full Citation: Batchelder et al., U.S. Patent Application Publication No. 2011/0233804 A1, titled "Systems and methods for identifying consumable materials in three-dimensional modeling systems."
- Publication Date: September 29, 2011.
- Brief Description: This publication describes various systems and methods for identifying consumable materials, often involving reading encoded markings from filament segments.
- Potential Anticipation: Relates to material tracking and control, not the purge tower method.

Conclusion Regarding Anticipation under 35 U.S.C. § 102:

Based on the review of the cited prior art, no single reference explicitly or inherently discloses every element of Claim 1 of US9421713B2, particularly the specific step where the "purge operation comprises printing at least one purge tower in a layer-by-layer manner." While many references address aspects of multi-head additive manufacturing, switching between print heads/modes, and performing purge operations (albeit at a dedicated station), none combine these elements with the unique teaching of constructing a purge tower on the build platform for this purpose. The same applies to dependent claims 2, 3, and 4, which further elaborate on the multi-head switching and the geometric specifics of the purge tower, respectively. Therefore, none of the cited prior art fully anticipates Claim 1 or its dependent claims under 35 U.S.C. § 102.