Patent Description:
According to the present disclosure, it would be desirable to utilize an additive manufacturing machine or system to additively print onto pre-exiting workpieces, including additively printing onto a plurality of pre-existing workpieces as part of a single build. When additively printing onto such workpieces, it would be desirable for additive manufacturing machines, systems, and methods to additively print onto pre-existing workpieces with sufficient precision and accuracy so as to provide near net shape components. Accordingly, there exists a need for improved additive manufacturing machines and systems, and methods of additively printing on workpieces.

The workpieces contemplated by the present disclosure include originally fabricated workpieces, as well as workpieces intended to be repaired, rebuilt, upgraded, and so forth, such as machine or device components that may experience damage, wear, and/or degradation throughout their service life. It would be desirable to additively print on workpieces such as machine or device components so as to repair, rebuild, or upgrade such components. It would also be desirable to additively print on workpieces so as to produce new components such as components that may exhibit an enhanced performance or service life.

One example of a machine or device component includes an air foil, such as a compressor blade or a turbine blade used in a turbomachine. These air foils frequently experience damage, wear, and/or degradation throughout their service life. For example, serviced air foils, such as compressor blades of a gas turbine engine show erosion, defects, and/or cracks after long term use. Specifically, for example, such blades are subject to significant high stresses and temperatures which inevitably cause blades to wear over time, particularly near the tip of the blade. For example, blade tips are susceptible to wear or damage from friction or rubbing between the blade tips and turbomachine shrouds, from chemical degradation or oxidation from hot gasses, from fatigue caused by cyclic loading and unloading, from diffusion creep of crystalline lattices, and so forth.

Notably, worn or damaged blades may result in machine failure or performance degradation if not corrected. Specifically, such blades may cause a turbomachine to exhibit reduced operating efficiency as gaps between blade tips and turbomachine shrouds may allow gasses to leak through the turbomachine stages without being converted to mechanical energy. When efficiency drops below specified levels, the turbomachine is typically removed from service for overhaul and repair. Moreover, weakened blades may result in complete fractures and catastrophic failure of the engine.

As a result, compressor blades for a turbomachine are typically the target of frequent inspections, repairs, or replacements. It is typically expensive to replace such blades altogether, however, some can be repaired for extended lifetime at relatively low cost (as compared to replacement with entirely new blades). Nevertheless, traditional repair processes tend to be labor intensive and time consuming.

For example, a traditional repair process uses a welding/cladding technique whereby repair material may be supplied to a repair surface in either powder or wire form, and the repair material may be melted and bonded to the repair surface using a focused power source such as a laser, e-beam, plasma arc, or the like. However, blades repaired with such a welding/cladding technique also undergo tedious post-processing to achieve the target geometry and surface finish. Specifically, due to the bulky feature size of the welding/cladding repair material bonded to the repair surface, the repaired blades require heavy machining to remove extra material followed by polishing to achieve a target surface finish. Notably, such machining and polishing processes are performed on a single blade at a time, are labor intensive and tedious, and result in large overall labor costs for a single repair.

Alternatively, other direct-energy-deposition (DED) methods may be used for blade repair, e.g., such as cold spray, which directs high-speed metal powders to bombard the target or base component such that the powders deform and deposit on the base component. However, none of these DED methods are suitable for batch processing or for repairing a large number of components in a time-efficient manner, thus providing little or no business value.

Accordingly, there exists a need for improved apparatuses, systems, and methods for additively manufacturing near net shape components that include an extension segment additively printed on a workpiece, including apparatuses, systems, and methods of repairing workpieces such as compressor blades and turbine blades. <CIT> relates to a method for additive manufacturing. <CIT> relates to an additive manufacturing apparatus and method. <CIT> relates to an rapid action clamping cylinder.

Aspects and advantages will be set forth in part in the following description, or may be obvious from the description, or may be learned through practicing the presently disclosed subject matter.

In one aspect, the present disclosure embraces build plate-clamping assemblies. The plate-clamping assembly includes a work station having a build plate-receiving surface and a lock-pin extending from the build plate-receiving surface of the work station. The lock-pin may include a hollow pin body, a piston disposed within the hollow pin body, with the piston axially movable from a retracted position to an actuated position, and a plurality of detents, with the plurality of detents radially extensible through respective ones of a plurality of detent-apertures in the hollow pin body responsive to the piston having been axially moved to the actuated position; characterized in that the lock-pin comprises a flushing channel defining a pathway for a fluid to flow from a fluid source and discharge from the hollow pin body so as to flush debris from the lock-pin.

In another aspect, the present disclosure embraces methods working on workpieces at multiple work stations. The mthod includes include lockingly engaging a build plate at a first work station, performing a first work-step on a plurality of workpieces secured to the build plate, releasing the build plate from the first work station, lockingly engaging the build plate at a second work station, wherein the lock-pin comprises a flushing channel defining a pathway for a fluid to flow from a fluid source and discharge from the hollow pin body so as to flush debris from the lock-pin, and performing a second work-step on the plurality of workpieces secured to the build plate. The first work station may have a first lock-pin extending from a first build plate-receiving surface, and the build plate may include a socket configured to lockingly engage with the first lock-pin. The second work station may have a second lock-pin extending from a second build plate-receiving surface, and the socket of the build plate may also be configured to lockingly engage with the second lock-pin.

These and other features, aspects and advantages will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments and, together with the description, serve to explain certain principles of the presently disclosed subject matter.

A full and enabling disclosure, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended Figures, in which:.

Reference now will be made in detail to exemplary embodiments of the presently disclosed subject matter, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation and should not be interpreted as limiting the present disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the scope or spirit of the present disclosure. Thus, it is intended that the present disclosure covers such modifications and variations as come within the scope of the appended claims.

It is understood that terms such as "top", "bottom", "outward", "inward", and the like are words of convenience and are not to be construed as limiting terms. The terms "a" and "an" do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

Here and throughout the specification and claims, range limitations are combined and interchanged, and such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise.

As described in detail below, exemplary embodiments of the present subject matter involve the use of additive manufacturing machines or methods. As used herein, the terms "additively manufactured" or "additive manufacturing techniques or processes" refer generally to manufacturing processes wherein successive layers of material(s) are provided on each other to "build-up," layer-by-layer, a three-dimensional component. The successive layers generally fuse together to form a monolithic component which may have a variety of integral subcomponents.

As used herein, the term "near net shape" refers to an additively printed feature that has an as-printed shape that is very close to the final "net" shape. A near net shape component may undergo surface finishing such as polishing, buffing, and the like, but does not require heaving machining so as to achieve a final "net" shape. By way of example, a near net shape may differ from a final net shape by about <NUM>,<NUM> microns or less, such as about <NUM>,<NUM> or less, such as about <NUM> or less, or such as about <NUM> or less or such as about <NUM> or less or such as about <NUM> or less.

Although additive manufacturing technology is described herein as enabling fabrication of complex objects by building objects point-by-point, layer-by-layer, typically in a vertical direction, other methods of fabrication are possible and within the scope of the present subject matter. For example, although the discussion herein refers to the addition of material to form successive layers, one skilled in the art will appreciate that the methods and structures disclosed herein may be practiced with any additive manufacturing technique or manufacturing technology. For example, embodiments of the present invention may use layer-additive processes, layer-subtractive processes, or hybrid processes.

Suitable additive manufacturing techniques in accordance with the present disclosure include, for example, Fused Deposition Modeling (FDM), Selective Laser Sintering (SLS), 3D printing such as by inkjets and laserjets, Sterolithography (SLA), Direct Selective Laser Sintering (DSLS), Electron Beam Sintering (EBS), Electron Beam Melting (EBM), Laser Engineered Net Shaping (LENS), Laser Net Shape Manufacturing (LNSM), Direct Metal Deposition (DMD), Digital Light Processing (DLP), Direct Selective Laser Melting (DSLM), Selective Laser Melting (SLM), Direct Metal Laser Melting (DMI,M), and other known processes.

In addition to using a direct metal laser sintering (DMI,S) or direct metal laser melting (DMI,M) process where an energy source is used to selectively sinter or melt portions of a layer of powder, it should be appreciated that according to alternative embodiments, the additive manufacturing process may be a "binder jetting" process. In this regard, binder jetting involves successively depositing layers of additive powder in a similar manner as described above. However, instead of using an energy source to generate an energy beam to selectively melt or fuse the additive powders, binder jetting involves selectively depositing a liquid binding agent onto each layer of powder. The liquid binding agent may be, for example, a photo-curable polymer or another liquid bonding agent. Other suitable additive manufacturing methods and variants are intended to be within the scope of the present subject matter.

The additive manufacturing processes described herein may be used for forming components using any suitable material. For example, the material may be plastic, metal, concrete, ceramic, polymer, epoxy, photopolymer resin, or any other suitable material that may be in solid, liquid, powder, sheet material, wire, or any other suitable form. More specifically, according to exemplary embodiments of the present subject matter, the additively manufactured components described herein may be formed in part, in whole, or in some combination of materials including but not limited to pure metals, nickel alloys, chrome alloys, titanium, titanium alloys, magnesium, magnesium alloys, aluminum, aluminum alloys, iron, iron alloys, stainless steel, and nickel or cobalt based superalloys (e.g., those available under the name Inconel® available from Special Metals Corporation). These materials are examples of materials suitable for use in the additive manufacturing processes described herein and may be generally referred to as "additive materials.

In addition, one skilled in the art will appreciate that a variety of materials and methods for bonding those materials may be used and are contemplated as within the scope of the present disclosure. As used herein, references to "fusing" may refer to any suitable process for creating a bonded layer of any of the above materials. For example, if an object is made from polymer, fusing may refer to creating a thermoset bond between polymer materials. If the object is epoxy, the bond may be formed by a crosslinking process. If the material is ceramic, the bond may be formed by a sintering process. If the material is powdered metal, the bond may be formed by a melting or sintering process. One skilled in the art will appreciate that other methods of fusing materials to make a component by additive manufacturing are possible, and the presently disclosed subject matter may be practiced with those methods.

In addition, the additive manufacturing process disclosed herein allows a single component to be formed from multiple materials. Thus, the components described herein may be formed from any suitable mixtures of the above materials. For example, a component may include multiple layers, segments, or parts that are formed using different materials, processes, and/or on different additive manufacturing machines. In this manner, components may be constructed which have different materials and material properties for meeting the demands of any particular application. In addition, although the components described herein are constructed entirely by additive manufacturing processes, it should be appreciated that in alternate embodiments, all or a portion of these components may be formed via casting, machining, and/or any other suitable manufacturing process. Indeed, any suitable combination of materials and manufacturing methods may be used to form these components.

An exemplary additive manufacturing process will now be described. Additive manufacturing processes fabricate components using three-dimensional (3D) information, for example a three-dimensional computer model, of the component. Accordingly, a three-dimensional design model of the component may be defined prior to manufacturing. In this regard, a model or prototype of the component may be scanned to determine the three-dimensional information of the component. As another example, a model of the component may be constructed using a suitable computer aided design (CAD) program to define the three-dimensional design model of the component.

The design model may include 3D numeric coordinates of the entire configuration of the component including both external and internal surfaces of the component. For example, the design model may define the body, the surface, and/or internal passageways such as openings, support structures, etc. In one exemplary embodiment, the three-dimensional design model is converted into a plurality of slices or segments, e.g., along a central (e.g., vertical) axis of the component or any other suitable axis. Each slice may define a thin cross section of the component for a predetermined height of the slice. The plurality of successive cross-sectional slices together form the 3D component. The component is then "built-up" slice-by-slice, or layer-by-layer, until finished.

In this manner, the components described herein may be fabricated using the additive process, or more specifically each layer is successively formed, e.g., by fusing or polymerizing a plastic using laser energy or heat or by sintering or melting metal powder. For example, a particular type of additive manufacturing process may use an energy beam, for example, an electron beam or electromagnetic radiation such as a laser beam, to sinter or melt a powder material. Any suitable laser and laser parameters may be used, including considerations with respect to power, laser beam spot size, and scanning velocity. The build material may be formed by any suitable powder or material selected for enhanced strength, durability, and useful life, particularly at high temperatures.

Each successive layer may be, for example, between about <NUM> and <NUM>, although the thickness may be selected based on any number of parameters and may be any suitable size according to alternative embodiments. Therefore, utilizing the additive formation methods described above, the components described herein may have cross sections as thin as one thickness of an associated powder layer, e.g., <NUM>, utilized during the additive formation process.

In addition, utilizing an additive process, the surface finish and features of the components may vary as need depending on the application. For example, the surface finish may be adjusted (e.g., made smoother or rougher) by selecting appropriate laser scan parameters (e.g., laser power, scan speed, laser focal spot size, etc.) during the additive process, especially in the periphery of a cross-sectional layer which corresponds to the part surface. For example, a rougher finish may be achieved by increasing laser scan speed or decreasing the size of the melt pool formed, and a smoother finish may be achieved by decreasing laser scan speed or increasing the size of the melt pool formed. The scanning pattern and/or laser power can also be changed to change the surface finish in a selected area.

After fabrication of the component is complete, various post-processing procedures may be applied to the component. For example, post processing procedures may include removal of excess powder by, for example, blowing or vacuuming. Other post processing procedures may include a stress relief process. Additionally, thermal, mechanical, and/or chemical post processing procedures can be used to finish the part to achieve a desired strength, surface finish, and other component properties or features.

Notably, in exemplary embodiments, several aspects and features of the present subject matter were previously not possible due to manufacturing restraints. However, the present inventors have advantageously utilized current advances in additive manufacturing techniques to improve various components and the method of additively manufacturing such components. While the present disclosure is not limited to the use of additive manufacturing to form these components generally, additive manufacturing does provide a variety of manufacturing advantages, including ease of manufacturing, reduced cost, greater accuracy, etc..

Also, the additive manufacturing methods described above enable much more complex and intricate shapes and contours of the components described herein to be formed with a very high level of precision. For example, such components may include thin additively manufactured layers, cross sectional features, and component contours. In addition, the additive manufacturing process enables the manufacture of a single component having different materials such that different portions of the component may exhibit different performance characteristics. The successive, additive nature of the manufacturing process enables the construction of these novel features. As a result, components formed using the methods described herein may exhibit improved performance and reliability.

The present disclosure generally provides additive manufacturing machines, systems, and methods configured to additively print on pre-existing workpieces. The pre-existing workpieces may include new workpieces as well as workpieces being repaired, rebuilt, or upgraded. In one aspect, build plate clamping-assemblies are provided that may be configured to align a build plate with coordinates of an additive manufacturing system with a high degree of precision and accuracy. The presently disclosed build plates may include sockets configured to fit within a socket-receiving recess with a tolerance selected to allow for thermal expansion during an additive manufacturing process, while still providing a highly precise and accurate locking engagement. For example, using the presently disclosed build plate-clamping assemblies, a build plate may be lockingly engaged with a work station within a tolerance of from about <NUM> micrometers to about <NUM> micrometers, such as from about <NUM> to about <NUM>, such as about <NUM> or less, such as about <NUM> or less, such as about <NUM> or less, or such as about <NUM> or less.

Exemplary build plate-clamping assemblies may include one or more lock-pins extending from a build plate-receiving surface of a work station. The one or more lock-pins may include one or more detents such as detent balls, which may be radially extensible so as to lockingly engage with one or more sockets of a build plate. The lock-pins may be pneumatically actuated so as to allow for quickly engaging and disengaging the build plate with the build plate-receiving surface. Alternatively, the lock-pins can be actuated using any desirable motive force, including an electrical actuator such as a piezoelectric switch, or a manual actuator such as a set screw.

The lock-pins may lockingly engage with the corresponding sockets of the build plate with sufficient accuracy and precision so as to align the build plate and/or one or more workpieces secured to the build plate to coordinates of the additive manufacturing system, including coordinates of a vision system and/or coordinates of an additive manufacturing machine. With the build plate and/or the one or more workpieces aligned to such coordinates, a vision system and an additive manufacturing machine may work in concert with one another, using the vision system to obtain digital representations of the workpieces, and using the additive manufacturing machine to additively print extension segments on the workpieces according to print commands generated based on the digital representations of the workpieces obtained from the vision system. For example, the digital representations may include the respective workpiece-interfaces of the workpieces, and the print commands may be configured to cause the additive manufacturing machine to additively print extension segments on the workpiece-interfaces so as to provide near net shape components.

The presently disclosed lock-pins includes flushing channels configured to allow a fluid to flush debris such as powder from the lock-pin, such as through one or more lock-pin apertures and/or one or more flushing apertures. The flushing channel provide for self-cleaning of the lock-pins so as to avoid powder from the additive manufacturing system from interfering with the operation of the lock-pins or prematurely wearing or damaging the various components that make up the build plate-clamping assembly.

The presently disclosed build plate-clamping assemblies, systems, and methods described herein allow for additively printing on the workpiece-interfaces of a plurality of workpieces simultaneously or concurrently as part of the same build. Among other advantages, such build plate-clamping assemblies may provide for improved productivity and reduced labor and time consumed when rebuilding workpieces. Additionally, alignment of the build plate and/or the one or more workpieces to additive manufacturing system coordinates facilitates production of near net shape components when additively printing extension segments on a plurality of workpieces.

Exemplary embodiments of an additive manufacturing system <NUM> are shown in <FIG>. An exemplary additive manufacturing system <NUM> includes a vision system <NUM>, an additive manufacturing machine <NUM>, and a control system <NUM> operably configured to control the vision system <NUM> and/or the additive manufacturing machine <NUM>. The vision system <NUM> and the additive manufacturing machine <NUM> may be provided as a single, integrated unit or as separate stand-alone units. The vision system <NUM> and the additive manufacturing machine <NUM> may be operably coupled with one another via a communication interface utilizing wired or wireless communication lines, which may provide a direct connection between the vision system <NUM> and the additive manufacturing machine <NUM>. The control system <NUM> may include one or more control systems <NUM>. For example, a single control system <NUM> may be operably configured to control operations of the vision system <NUM> and the additive manufacturing machine <NUM>, or separate control systems <NUM> may be operably configured to respectively control the vision system <NUM> and the additive manufacturing machine <NUM>. A control system <NUM> may be realized as part of the vision system <NUM>, as part of the additive manufacturing machine <NUM>, and/or as a stand-alone unit provided separately from the vision system <NUM> and/or the additive manufacturing machine <NUM>. A control system <NUM> may be operably coupled with the vision system <NUM> and/or the additive manufacturing machine <NUM> via a communication interface utilizing wired or wireless communication lines, which may provide a direct connection between the control system <NUM> and the vision system <NUM> and/or between the control system <NUM> and the additive manufacturing machine <NUM>. An exemplary additive manufacturing system <NUM> may optionally include a user interface <NUM> and/or a management system <NUM>.

In some embodiments, a first control system <NUM> may generate one or more print commands and/or transmit the one or more print commands to a second control system <NUM>, and the second control system <NUM> may cause the additive manufacturing machine <NUM> to additively print the extension segments based at least in part on the print commands. The first control system <NUM> may be realized as part of a vision system <NUM>, and/or the second control system <NUM> may be realized as part of the additive manufacturing machine <NUM>. Alternatively, or in addition, the first control system <NUM> and/or the second control system <NUM> may be realized stand-alone units separate from the vision system <NUM> and/or the additive manufacturing machine <NUM>.

The vision system <NUM> may include any suitable camera or cameras <NUM> or other machine vision device that may be operably configured to obtain image data that includes a digital representation of one or more fields of view <NUM>. Such a digital representation may sometimes be referred to as a digital image or an image; however, it will be appreciated that the present disclosure may be practiced without rendering such a digital representation in human-visible form. Nevertheless, in some embodiments, a human-visible image corresponding to a field of view <NUM> may be displayed on the user interface <NUM> based at least in part on such a digital representation of one or more fields of view <NUM>.

The vision system <NUM> allows the additive manufacturing system <NUM> to obtain information pertaining to one or more workpieces <NUM> onto which one or more extension segments may be respectively additively printed. In particular, the vision system <NUM> allows the one or more workpieces <NUM> to be located and defined so that the additive manufacturing machine <NUM> may be instructed to print one or more extension segments on a corresponding one or more workpieces <NUM> with suitably high accuracy and precision. The one or more workpieces <NUM> may be secured to a build plate <NUM> with a workpiece-interface (e.g. a top surface) <NUM> of the respective workpieces <NUM> aligned to a build plane <NUM>. The build plate <NUM> may be secured to a vision system-work station <NUM> with one or more vision system-lock-pins <NUM>. The one or more vision system-lock-pins <NUM> may be configured according to the present disclosure so as to position the build plate <NUM> on the vision system-work station <NUM> with sufficiently high accuracy and precision.

The one or more cameras <NUM> of the vision system <NUM> may be configured to obtain two-dimensional or three-dimensional image data, including a two-dimensional digital representation of a field of view <NUM> and/or a three-dimensional digital representation of a field of view <NUM>. Alignment of the workpiece-interfaces <NUM> with the build plane <NUM> allows the one or more cameras <NUM> to obtain higher quality images. For example, the one or more cameras <NUM> may have a focal length adjusted or adjustable to the build plane <NUM>. With the workpiece-interface <NUM> of one or more workpieces <NUM> aligned to the build plane <NUM>, the one or more cameras may readily obtain digital images of the workpiece-interfaces <NUM>. The one or more cameras <NUM> may include a field of view <NUM> that that encompasses all or a portion of the one or more workpieces <NUM> secured to the build plate <NUM>. For example, a single field of view <NUM> may be wide enough to encompass a plurality of workpieces <NUM>, such as each of a plurality of workpieces secured to a build plate <NUM>. Alternatively, a field of view <NUM> may more narrowly focus on an individual workpiece <NUM> such that digital representations of respective workpieces <NUM> are obtained separately. It will be appreciated that separately obtained digital images may be stitched together to obtain a digital representation of a plurality of workpieces <NUM>. In some embodiments, the camera <NUM> may include a collimated lens configured to provide a flat focal plane, such that workpieces or portions thereof located towards the periphery of the field of view <NUM> are not distorted. Additionally, or in the alternative, the vision system <NUM> may utilize a distortion correction algorithm to address any such distortion.

Image data obtained by the vision system <NUM>, including a digital representation of one or more workpieces <NUM> may be transmitted to the control system <NUM>. The control system <NUM> may be configured to determine a workpiece-interface <NUM> of each of a plurality of workpieces <NUM> from one or more digital representations of one or more fields of view <NUM> having been captured by the vision system <NUM>, and then determine one or more coordinates of the workpiece-interface <NUM> of respective ones of the plurality of workpieces <NUM>. Based on the one or more digital representations, the control system <NUM> may generate one or more print commands, which may be transmitted to an additive manufacturing machine <NUM> such that the additive manufacturing machine <NUM> may additively print a plurality of extension segments on respective ones of the plurality of workpieces <NUM>. The one or more print commands may be configured to additively print a plurality of extension segments with each respective one of the plurality of extension segments being located on the workpiece-interface <NUM> of a corresponding workpiece <NUM>.

The additive manufacturing machine <NUM> may utilize any desired additive manufacturing technology. In an exemplary embodiment, the additive manufacturing machine may utilize a powder bed fusion (PBF) technology, such as direct metal laser melting (DMI,M), electron beam melting (EBM), selective laser melting (SLM), directed metal laser sintering (DMLS), or selective laser sintering (SLS). The additive manufacturing machine <NUM> may include any such additive manufacturing technology, or any other suitable additive manufacturing technology may also be used. By way of example, using a powder bed fusion technology, respective ones of a plurality of extension segments may be additively printed on corresponding respective ones of a plurality of workpieces <NUM> in a layer-by-layer manner by melting or fusing a layer of powder material to the workpiece-interface <NUM>. In some embodiments, a component may be additively printed by melting or fusing a single layer of powered material to the workpiece-interface <NUM>. Additionally, or in the alternative, subsequent layers of powder material may be sequentially melted or fused to one another.

Still referring to <FIG>, an exemplary additive manufacturing machine <NUM> includes a powder supply chamber <NUM> that contains a supply of powder <NUM>, and a build chamber <NUM>. A build plate <NUM> having one or more workpieces <NUM> secured thereto may be positioned in the build chamber <NUM>, where the workpieces <NUM> may be additively printed in a layer-by-layer manner. The powder supply chamber <NUM> includes a powder piston <NUM> which elevates a powder floor <NUM> during operation of the system <NUM>. As the powder floor <NUM> elevates, a portion of the powder <NUM> is forced out of the powder supply chamber <NUM>.

A recoater <NUM>, such as a roller or a blade, pushes some of the powder <NUM> across a work surface <NUM> and onto an additive manufacturing-work station <NUM>. The build plate <NUM> may be secured to the additive manufacturing-work station <NUM> with one or more additive manufacturing machine-lock-pins <NUM>. The one or more additive manufacturing machine-lock-pins <NUM> may be configured according to the present disclosure so as to position the build plate <NUM> on the additive manufacturing-work station <NUM> and/or within the build chamber <NUM> with sufficiently high accuracy and precision. The workpieces <NUM> may be secured to the build plate <NUM> prior to securing the build plate <NUM> to the additive manufacturing-work station <NUM>. The recoater <NUM> fills the build chamber <NUM> with powder <NUM> and then sequentially distributes thin layers of powder <NUM> across a build plane <NUM> near the top of the workpieces <NUM> to additively print sequential layers of the workpieces <NUM>. For example, the thin layers of powder <NUM> may be about <NUM> to <NUM> microns thick, such as about <NUM> to <NUM> thick, such as about <NUM> to <NUM> thick, or such as about <NUM> to <NUM> thick, or such as about <NUM> to <NUM> thick. The build plane <NUM> represents a plane corresponding to a next layer of the workpieces <NUM> to be formed from the powder <NUM>.

To form a layer of an extension segment on the workpiece <NUM> (e.g., an interface layer or a subsequent layer), an energy source <NUM> directs an energy beam <NUM> such as a laser or an electron beam onto the thin layer of powder <NUM> along the build plane <NUM> to melt or fuse the powder <NUM> to the top of the workpieces <NUM> (e.g., to melt or fuse a layer to the workpiece-interfaces <NUM> and/or melt or fuse subsequent layers thereto). A scanner <NUM> controls the path of the beam so as to melt or fuse only the portions of the powder <NUM> layer that are to become melted or fused to the workpieces <NUM>. Typically, with a DMLM, EBM, or SLM system, the powder <NUM> is fully melted, with respective layers being melted or re-melted with respective passes of the energy beam <NUM>. Conversely, with DMLS, or SLS systems, layers of powder <NUM> are sintered, fusing particles of powder <NUM> with one another generally without reaching the melting point of the powder <NUM>. After a layer of powder <NUM> is melted or fused to the workpieces <NUM>, a build piston <NUM> gradually lowers the additive manufacturing-work station <NUM> by an increment, defining a next build plane <NUM> for a next layer of powder <NUM> and the recoater <NUM> to distributes the next layer of powder <NUM> across the build plane <NUM>. Sequential layers of powder <NUM> may be melted or fused to the workpieces <NUM> in this manner until the additive printing process is complete.

Now referring to <FIG> and <FIG>, an exemplary build plate-clamping assembly will be described. An exemplary build plate-clamping assembly includes a work station <NUM>, such as the work station shown in <FIG>. An exemplary build plate-clamping assembly may additionally include a build plate <NUM> corresponding to the work station, such as shown in <FIG>. The work station <NUM> shown in <FIG> may depict a vision system-work station <NUM> and/or an additive manufacturing-work station <NUM>. As shown in <FIG>, an exemplary work station <NUM> includes a build plate-receiving surface <NUM>, and one or more lock-pins <NUM> extending from the build plate-receiving surface <NUM> of the work station <NUM>. The one or more lock-pins <NUM> include one or more detents <NUM> such as detent balls or other locking elements extensible radially from the respective lock-pin <NUM>. The use of one or more lock-pins <NUM> that include detents <NUM> advantageously allow for the build plate <NUM> to be secured to the build-plate receiving surface <NUM>, while also allowing for the build plate <NUM> to be aligned laterally, vertically, and rotationally with respect to the build-plate-receiving surface <NUM>.

While two lock-pins <NUM> are shown in <FIG>, it will be appreciated that the depicted embodiment is provided by way of example and not to be limiting. In fact, any desired number of lock-pins <NUM> may be provided without departing from the spirit and scope of the present disclosure, such as, for example, at least one lock-pin <NUM>, at least two lock-pins <NUM>, at least three lock-pins <NUM>, or at least four lock-pins <NUM>. Additionally, while the lock-pins depicted in <FIG> include a plurality of detents <NUM>, it will be appreciated that the number of detents <NUM> depicted is provided by way of example and not to be limiting. Various embodiments of a lock-pin <NUM> may include any desired number of detents <NUM> without departing from the spirit and scope of the present disclosure, including, for example, at least one detent <NUM>, at least two detents <NUM>, at least three detents <NUM>, or at least four detents <NUM>.

The number of lock-pins <NUM> and/or the number of detents <NUM> may be selected, for example, to increase the hold-down or security with which the build plate <NUM> is secured to the build-plate. In addition to the lock-pins <NUM>, the build plate-receiving surface <NUM> may include other features that may help align a build plate <NUM> with the build plate-receiving surface <NUM>, such as grooves, notches, ridges, pins, recesses, and so forth which may be configured to mate with corresponding features of the build plate <NUM>. Such other features may be configured to provide vertical, lateral, and/or rotational alignment of the build plate <NUM> with the build plate-receiving surface <NUM>.

Now referring to <FIG>, various aspects of an exemplary build plate <NUM> will be described. A build plate <NUM> may include one or more features corresponding to the build plate-receiving surface <NUM> of the work station <NUM>, so as to allow the build plate <NUM> to be clamped to the work station <NUM> at least in part by one or more lock-pins <NUM>. As shown in <FIG>, an exemplary build plate <NUM> includes one or more sockets <NUM> configured and arranged about the build plate <NUM> so as to correspond to one or more lock-pins <NUM> of the work station <NUM>. A socket <NUM> may define an integral, seamless portion of the build plate <NUM>. Alternatively, as shown, a socket <NUM> may installed in a socket-receiving recess <NUM> in the build plate, such as with an interference fit. The interference fit may be sized so as to allow the socket <NUM> to float within the socket-receiving recess <NUM> with a tolerance selected to allow for thermal expansion during an additive manufacturing process. In an alternative embodiment, the socket <NUM> may be fixed to the build plate <NUM> and the lock-pins <NUM> may be allowed to float, for example, so as to similarly allow for thermal expansion during an additive manufacturing process.

Regardless of whether a socket <NUM> defines an integral, seamless portion of the build plate <NUM> or is installed in a socket-receiving recess <NUM>, the socket <NUM> may include an inside surface <NUM> defining an engagement surface configured to allow the lock-pin to lockingly engage with the socket <NUM>. The engagement surface may extend across all or a portion of the inside surface <NUM> of the socket <NUM>, and through a portion of the build plate <NUM> or entirely through the build plate <NUM>.

In some embodiments, the engagement surface may include one or more recesses corresponding to respective ones of the detents <NUM>, so as to provide rotational alignment of the build plate <NUM> with the build plate-receiving surface <NUM>. In this way, a single lock-pin <NUM> may provide both lateral alignment and rotational alignment of the build plate <NUM> with the build plate-receiving surface <NUM>.

In some embodiments, a variety differently configured sockets <NUM> may be interchangeably installed in a socket-receiving recess <NUM>. For example, differently configured sockets <NUM> may be provided so as to accommodate differently configured lock-pins <NUM>. While two sockets <NUM> are shown in <FIG>, it will be appreciated that the depicted embodiment is provided by way of example and not to be limiting. In fact, any desired number of sockets <NUM> may be provided without departing from the spirit and scope of the present disclosure, such as, for example, at least one socket <NUM>, at least two sockets <NUM>, at least three sockets <NUM>, or at least four sockets <NUM>. The number of sockets <NUM>, however, will typically correspond in number to at least the number of lock-pins <NUM> provided on a build plate-receiving surface <NUM> of a work station <NUM>. However, in some embodiments, the number of sockets <NUM> may exceed the number of lock-pins <NUM> provided on a build plate-receiving surface <NUM> of a work station <NUM>. In some embodiments, a plurality of build plate-receiving surfaces <NUM> may be defined on a work station <NUM>, such that the work station <NUM> may receive may receive a plurality of build plates <NUM>, and/or such that the work station <NUM> may receive a variety of different build plates <NUM>, such as build plates <NUM> that differ in respect of the number and/or configuration of sockets <NUM>.

Still referring to <FIG>, in some embodiments, when the sockets <NUM> are installed in a socket-receiving recess <NUM>, the build plate <NUM> may additionally include one or more socket bolt-receiving bores <NUM> intersecting a socket-receiving recess <NUM>. The one or more socket bolt-receiving bores <NUM> may be configured to receive a socket locking-bolt <NUM>, and such as socket locking-bolt <NUM> may be insertable therein such as by a threaded fit and/or an interference fit. The socket <NUM> may be lockingly engageable with the build plate <NUM> (e.g., with the socket-receiving recess <NUM>) at least in part by one or more socket bolts <NUM> having been inserted into corresponding socket bolt-receiving bores <NUM>. For example, an outside surface of a socket <NUM> may include a socket bolt-engaging channel <NUM> disposed about at least a portion of the outer surface of the socket <NUM>. The location of the socket bolt-engaging channel <NUM> may be selected to align with the socket bolt-receiving bore <NUM> intersecting the socket-receiving recess <NUM>, such that the socket locking-bolt <NUM> may lockingly engage with the socket bolt-engaging channel <NUM>.

In an exemplary embodiment, a build plate <NUM> may include a first a socket bolt-receiving bore <NUM> intersecting a first side of a socket-receiving recess <NUM> and a second a socket bolt-receiving bore <NUM> intersecting a second side of the socket-receiving recess <NUM>. The first socket bolt-receiving bore <NUM> may be configured to receive a first socket locking-bolt <NUM> insertable therein, and the second socket bolt-receiving bore <NUM> may be configured to receive a second socket locking-bolt <NUM> insertable therein. The first socket bolt-receiving bore <NUM> and the second socket bolt-receiving bore <NUM> may align with a socket bolt-engaging channel <NUM> on the outside surface of the socket <NUM>. The socket <NUM> may be lockingly engageable with the build plate <NUM> at least in part by the first socket locking-bolt <NUM> having been inserted into the first socket bolt-receiving bore <NUM> and engaging with the socket bolt-engaging channel <NUM> and/or the second socket locking-bolt <NUM> having been inserted into the second socket bolt-receiving bore <NUM> and engaging with the socket bolt-engaging channel <NUM>.

Now referring to <FIG>, further aspects of an exemplary lock-pin <NUM> will be described. As shown, an exemplary lock-pin <NUM> may include a hollow pin body <NUM> a piston <NUM> disposed within the hollow pin body <NUM>, such as within an axial piston pathway <NUM> configured and arranged to receive the piston <NUM>. The piston <NUM> may be axially movable so as to actuate and retract one or more detents <NUM>. The piston <NUM> may be axially movable from a retracted position located axially distal from the one or more detents <NUM> to an actuated position located axially proximal to the one or more detents <NUM>. The one or more detents <NUM> may be extensible radially from the respective lock-pin <NUM> through corresponding detent-apertures <NUM> in the hollow pin body <NUM> responsive to the piston <NUM> having been axially moved to the actuated position. The piston <NUM> may be actuable by any desired means, including a mechanical piston <NUM> actuable by a mechanical lever or the like, a pneumatic piston <NUM> actuable by a pneumatic fluid, a hydraulic piston <NUM> actuable by a hydraulic fluid, a magnetic piston <NUM> actuable by a magnetic source such as an electromagnet, and so forth.

In some embodiments, a lock-pin <NUM> may include a wedging element <NUM> disposed within the hollow pin body <NUM> between the piston <NUM> and the one or more detents <NUM>. The one or more wedging elements <NUM> may have a sloped or curved surface that slidably translates an axial movement <NUM> of the piston <NUM> to a radial movement (e.g., a radial extension and/or a radial retraction) <NUM> of the one or more detents <NUM>. For example, the one or more wedging elements <NUM> may radially extend the one or more detents <NUM> responsive to the piston <NUM> having been axially moved to the actuated position.

The one or more detents <NUM> may have any desired shape suitable for extending radially from the detent-apertures <NUM> through radial movement <NUM> responsive to slidably translating movement of a wedging element <NUM>. The one or more wedging elements <NUM> may have any desired shape that provides a suitably sloped or curved surface that slidably translates an axial movement <NUM> of the piston <NUM> to a radial movement <NUM> of the one or more detents <NUM>. As shown in <FIG>, the detents <NUM> and the wedging element <NUM> both have a spherical shape. However, it will be appreciated that a detent <NUM> and/or a wedging element <NUM> may be configured according to other suitable shapes, including frustoconical shapes and polyhedral shapes. In some embodiments, the wedging element <NUM> may be an integral part of the piston <NUM>, or the wedging element <NUM> may be omitted and the piston <NUM> may slidably translate axial movement <NUM> to a radial movement <NUM> of the one or more detents <NUM>. The spherical shaped detents <NUM> and the spherical shaped wedging element <NUM> may be desirable, however, so as to reduce friction between and allow the one or more detents <NUM> and/or the one or more wedging elements <NUM> to rotate freely within the hollow pin body <NUM>, against the detent-apertures <NUM>, and/or against the engagement surface of the socket <NUM>.

A detent-aperture <NUM> may provide an opening of sufficient size to allow a detent <NUM> to radially extend partially therethrough such that the detent <NUM> may lockingly engage with the engagement surface. A cross-sectional width of a detent-aperture <NUM> may be less than a cross-sectional width of a detent <NUM> so as to prevent the detent <NUM> from falling out of the detent-aperture <NUM>.

Referring now to <FIG>, further aspects of a build plate-clamping assembly <NUM> will be described. As shown in <FIG>, an exemplary build-plate clamping assembly <NUM> may include a work station <NUM> having a build plate-receiving surface <NUM>, and one or more lock-pins <NUM> extending from the build plate-receiving surface <NUM> of the work station <NUM>. The one or more lock-pins <NUM> may include a hollow pin body <NUM>, a piston <NUM> disposed within the hollow pin body <NUM>. The piston is axially movable from a retracted position <NUM> to an actuated position <NUM>, such that the piston <NUM> may actuate one or more detents <NUM> of respective ones of the one or more lock-pins <NUM>. The one or more detents <NUM> may be radially extensible through respective ones of a plurality of detent-apertures <NUM> in the hollow pin body <NUM> responsive to the piston <NUM> having been axially moved to the actuated position <NUM>.

The build-plate clamping assembly <NUM> may additionally include a build plate <NUM> configured to be clamped to the work station <NUM> at least in part by the one or more lock-pins <NUM>. The build plate <NUM> may include one or more sockets <NUM> that have an inside surface <NUM> defining an engagement surface <NUM> for the one or more detents <NUM> to lockingly engage the respective one of the one or more lock-pins <NUM> with the corresponding one of the one or more sockets <NUM>. In some embodiments, the engagement surface <NUM> may include an undercut, notch, groove, chamfer, or the like configured to lockingly engage the one or more detents <NUM>.

To lockingly engage a build plate <NUM> with a build plate-receiving surface <NUM> of a work station <NUM>, the build plate <NUM> may be positioned onto the build plate-receiving surface <NUM>, with the one or more lock-pins <NUM> fitting into a corresponding socket <NUM>. The build plate-clamping assembly <NUM> may include a fluid system <NUM> configured to actuate the one or more lock-pins <NUM>. The fluid system may include a fluid source <NUM>, which may include a fluid reservoir, a pump, and/or a compressor. The fluid source <NUM> may contain a fluid <NUM>, such as a pneumatic fluid or a hydraulic fluid. A piston <NUM> of a lock-pin <NUM> may be actuable by the fluid <NUM>, which may be supplied to a distal end of the piston <NUM>, which may be in fluid communication with the fluid source <NUM> via one or more piston fluid supply lines <NUM>. In some embodiments, a fluid supply valve <NUM> may be positioned at the one or more fluid supply lines. The fluid supply valve <NUM> may be movable to an open position to actuate the piston <NUM>, moving the piston to the actuated position <NUM>, and the fluid supply valve <NUM> may be movable to a closed position to retract the piston, moving the piston to the retracted position <NUM>.

The fluid source <NUM> may also supply fluid <NUM> to the flushing channel <NUM>, such as via one or more flushing fluid supply lines <NUM>. Optionally, a flushing fluid supply valve <NUM> may be positioned at the one or more fluid supply lines <NUM> so as to activate and deactivate a flow of fluid <NUM> to the flushing channel <NUM>. In some embodiments, at least a portion of the one or more flushing fluid supply lines <NUM> may define a pathway through a hollow pin body <NUM> of a lock-pin <NUM>. The flushing channel <NUM> and the pathway of the flushing fluid supply line <NUM> through the hollow pin body <NUM> may be configured to align and thereby fluidly communicate with one another when the piston <NUM> moves to a retracted position <NUM> and/or when the piston <NUM> moves to an actuated position <NUM>. In some embodiments, fluid communication between the flushing channel <NUM> and the flushing fluid supply line <NUM> may be established when the piston <NUM> moves to a retracted position <NUM>, such that debris may be flushed from the lock-pin <NUM> when the piston <NUM> moves to the retracted position <NUM>. For example, fluid <NUM> flow through the flushing channel <NUM> may be activated when removing a build plate <NUM> from a work station <NUM>. In this way, the fluid <NUM> flowing through the flushing channel <NUM> may prevent debris such as powder <NUM> from falling into the lock-pin <NUM> when removing the build plate <NUM> and/or the fluid <NUM> may flush any such debris from the lock-pin <NUM> that may otherwise accumulate in and/or around the lock-pin <NUM>.

<FIG> shows a build plate <NUM> lockingly engaged with a build plate-receiving surface <NUM> of a work station <NUM>. The fluid supply valve <NUM> is in an open position allowing fluid <NUM> to move a plurality of pistons <NUM> to an actuated position <NUM>. The pistons <NUM> move a respective wedging element <NUM> disposed within the hollow pin body <NUM> of the lock-pin <NUM> between the piston and the plurality of detents <NUM>. The wedging element <NUM> includes a sloped or curved surface configured to allow the wedging element <NUM> to slidably translates an axial movement <NUM> of the piston <NUM> to a radial extension of a plurality of detents <NUM> responsive to the piston <NUM> having been axially moved to the actuated position <NUM>. The plurality of detents <NUM> extend radially from corresponding detent-apertures <NUM>, thereby lockingly engaging with the engagement surface <NUM> of the sockets <NUM> corresponding to the respective lock-pins <NUM>. Any suitable piston <NUM> may be utilized, including a spring acting piston <NUM>, a spring return piston <NUM>, and/or a spring extend piston <NUM>. In an exemplary embodiment, the piston <NUM> may be a spring extend piston <NUM>, which advantageously prevents the piston <NUM> from retracting in the event of a loss in air pressure.

<FIG> shows a build plate <NUM> situated on the build plate-receiving surface <NUM> of a work station <NUM>, with fluid supply valve <NUM> in a closed position allowing the plurality of pistons <NUM> to move to a retracted position <NUM>. With the pistons <NUM> moved to the retracted position <NUM>, the wedging element <NUM> and the detents <NUM> may retract into the hollow body of the piston <NUM>, thereby disengaging the detents <NUM> from the engagement surface <NUM> of sockets <NUM> corresponding to the respective lock-pins <NUM>. With the detents <NUM> disengaged from the engagement surface <NUM>, the build plate <NUM> may be removed from the build plate-receiving surface <NUM>.

Referring again to <FIG>, in some embodiments, a lock-pin <NUM> may include a flushing channel <NUM> defining a pathway for a fluid <NUM> to flow from a fluid source <NUM> and discharge from the hollow pin body <NUM> so as to flush debris from the lock-pin <NUM>. The flushing channel <NUM> may be formed within the piston <NUM> and/or the hollow pin body <NUM> of the lock-pin <NUM>. In some embodiments, the flushing channel <NUM> may traverse helically along the piston <NUM> and/or the flushing channel <NUM> may traverse helically along the inner surface of the hollow piston body <NUM>. While a single flushing channel <NUM> is shown, it will be appreciated that any number of flushing channels <NUM> may be provided, such as at least one flushing channel, at least two flushing channels, and so forth, without departing from the spirit and scope of the present disclosure.

One or more flushing channels <NUM> may be in fluid communication with the plurality of detent-apertures <NUM> so as to allow the fluid <NUM> to flush debris such as powder <NUM> from the lock-pin <NUM> through the plurality of detent-apertures <NUM>. Additionally, or in the alternative, a lock-pin <NUM> may include one or more flushing apertures <NUM> disposed about the hollow pin body <NUM>. The one or more flushing apertures <NUM> may be in fluid communication with the one or more flushing channels <NUM> so as to allow the fluid <NUM> to flush debris such as powder <NUM> from the lock-pin <NUM>. An exemplary flushing pathway <NUM> may discharge through one or more flushing apertures <NUM> disposed at a proximal end <NUM> of the hollow pin body <NUM>. Another exemplary flushing pathway <NUM> may additionally or alternatively discharge through a plurality of flushing apertures <NUM> disposed about at least one of the plurality of detent-apertures <NUM>. The flushing channels <NUM> may be utilized before, during, and/or after lockingly engaging a build plate <NUM> at a work station <NUM> (e.g., before, during, and/or after the plurality of detents <NUM> have lockingly engaged the lock-pin <NUM> with the socket <NUM>).

Referring now to <FIG>, an exemplary workpiece-assembly <NUM> that includes a plurality of workpieces <NUM> secured to a build plate <NUM> is shown. The build plate <NUM> may be configured to align the workpieces <NUM> to respective registration points <NUM>. The registration points <NUM> may be mapped to a coordinate system, and the build plate-clamping assembly <NUM> may be configured to lockingly engage a build plate <NUM> to a build plate-receiving surface <NUM> of a work station such as a vision system-work station <NUM> or an additive manufacturing-work station <NUM>, so as to align the build plate <NUM> to the coordinate system such that the workpieces <NUM> may be aligned to the respective registration points <NUM>. <FIG> shows a workpiece-assembly <NUM> that includes a plurality of workpieces <NUM> secured to a build plate <NUM>.

A build plate-clamping assembly <NUM> may be used to facilitate additively printing an extension segment <NUM> on a workpiece <NUM>, including additively printing respective ones of a plurality of extension segments <NUM> on respective ones of a plurality of workpieces <NUM> as part of a single build. In some embodiments, a build plate-clamping assembly <NUM> may be configured to align the workpieces <NUM> to respective registration points <NUM> so as to facilitate image capture by the vision system <NUM>, so as to facilitate alignment of CAD models with the workpieces <NUM> (e.g., so that extension segments <NUM> as defined by a CAD model may be properly additively printed on the workpieces <NUM>), and/or so as to facilitate operability of the additive manufacturing machine <NUM>.

The arrangement depicted in <FIG> reflects a point in time prior to additively printing extension segments onto the workpiece-interfaces <NUM>. A build plate-clamping assembly <NUM> may be configured to lockingly engage a build plate <NUM> on a vision system-work station <NUM> with one or more vision system-lock-pins <NUM>, so as to align the build plate <NUM> to vision system-coordinates. The plurality of workpieces <NUM> may be secured to the build plate <NUM>, as shown in <FIG>, either before or after the build plate <NUM> is lockingly engaged with the build plate-receiving surface <NUM> of the vision system-work station <NUM>. The vision system <NUM> may obtain one or more digital representations of a workpiece-interface <NUM> of each of a plurality of workpieces <NUM> secured to the build plate <NUM>, with the workpieces <NUM> may be aligned to the respective registration points <NUM>. The digital representations may be obtained using one or more cameras <NUM> of the vison system <NUM>. The one or more cameras may be configured to provide one or more fields of view <NUM> that include the workpiece-interface <NUM> of each of the plurality of workpieces <NUM> secured to the build plate <NUM>.

The arrangement depicted in <FIG> shows the workpiece-assembly <NUM> of <FIG> but reflecting a point in time after an additive printing process. The build plate-clamping assembly <NUM> may be configured to lockingly engage the build plate <NUM> on an additive manufacturing-work station <NUM> with one or more additive manufacturing machine-lock-pins <NUM>, so as to align the build plate <NUM> to manufacturing machine-coordinates. As shown in <FIG>, the additive manufacturing machine <NUM> may form a plurality of components <NUM> by performing an additive printing process configured to additively print respective ones of a plurality of extension segments <NUM> onto respective ones of the plurality of workpieces <NUM>.

In addition to the build plate-clamping assembly <NUM>, the build plate <NUM> and/or workpiece-assembly <NUM> shown in <FIG> may include additional features that facilitate additively printing an extension segment <NUM> on a workpiece <NUM>, including additively printing respective ones of a plurality of extension segments <NUM> on respective ones of a plurality of workpieces <NUM> as part of a single build. In some embodiments, such additional features may further align the workpieces <NUM> to respective registration points <NUM> so as to facilitate image capture by the vision system <NUM>, so as to facilitate alignment of CAD models with the workpieces <NUM> (e.g., so that extension segments <NUM> as defined by a CAD model may be properly additively printed on the workpieces <NUM>), and/or so as to facilitate operability of the additive manufacturing machine <NUM>.

By way of example, as shown in <FIG>, such additional features of an exemplary workpiece-assembly <NUM> and/or build plate <NUM> may include one or more workpiece bays <NUM>. Each of the one or more workpiece bays <NUM> may include one or more workpiece docks <NUM>. The one or more workpiece bays <NUM> may additionally include one or more clamping mechanisms <NUM> which operate to secure one or more workpieces <NUM> to the build plate <NUM>. The one or more workpiece docks <NUM> may be configured to receive one or more workpiece shoes <NUM>, and the one or more workpiece shoes <NUM> may be respectively configured to receive a workpiece <NUM>. The one or more clamping mechanisms <NUM> may be configured to clamp the workpiece shoes <NUM> in position within the corresponding workpiece docks <NUM>.

A workpiece dock <NUM> and/or a workpiece shoe <NUM> may include one or more biasing members (not shown) configured to exert a biasing force (e.g., an upward or vertical biasing force) between the workpiece shoe <NUM> and the build plate <NUM> such as the bottom of the workpiece dock <NUM>. The biasing members may include one or more springs, one or more magnet pairs (e.g. permanent magnets or electromagnets), one or more piezoelectric actuator, or the like operable to exert such a biasing force. The biasing force exerted by the biasing members biases the workpiece shoe <NUM> so as to allow the workpiece-interfaces <NUM> (e.g., the top surfaces of the workpieces <NUM>) to be aligned with one another. By way of example, an alignment plate (not shown) may be placed on top of the workpieces <NUM> so as to partially compress the biasing members and bring the workpiece-interfaces <NUM> (e.g., the top surfaces of the workpieces <NUM>) into alignment with one another. In some embodiments, elevating blocks (not shown) may be placed between the build plate <NUM> and the alignment plate (not shown) to assist in positioning the alignment plate on top of the workpieces <NUM> at a desired height. With the workpiece-interfaces <NUM> aligned with one another, the clamping mechanism <NUM> may be tightened so as to secure the workpieces <NUM> to the build plate <NUM>.

The workpiece-assembly <NUM> shown in <FIG> may hold any number of workpieces <NUM>. As one example, the workpiece-assembly <NUM> shown may hold up to <NUM> workpieces <NUM>. As another example, a workpiece-assembly <NUM> may be configured to hold from <NUM> to <NUM> workpieces <NUM>, or more, such as from <NUM> to <NUM> workpieces <NUM>, such as from <NUM> to <NUM> workpieces <NUM>, such as from <NUM> to <NUM> workpieces <NUM>, such as from <NUM> to <NUM> workpieces <NUM>, such as from <NUM> to <NUM> workpieces <NUM>, such as from <NUM> to <NUM> workpieces <NUM>, such as from <NUM> to <NUM> workpieces <NUM>, such as from <NUM> to <NUM> workpieces <NUM>, such as at least <NUM> workpieces <NUM>, such as at least <NUM> workpieces <NUM>, such as at least <NUM> workpieces <NUM>, such as at least <NUM> workpieces <NUM>, such as at least <NUM> workpieces <NUM>, or such as at least <NUM> workpieces <NUM>.

In some embodiments, for example, when the workpieces <NUM> are airfoils such as compressor blades or turbine blades of a turbomachine, the workpiece-assembly <NUM> may be configured to hold a number of blades that corresponds to the number of blades in one or more stages of the compressor and/or turbine, as applicable. In this way, all of the blades of a given one or more stages of a turbine and/or compressor may be kept together and extension segments <NUM> may be additively printed thereon in one single build. It will be appreciated that the workpiece-assembly <NUM> and build plate <NUM> reflect one exemplary embodiment, which is provided by way of example and not to be limiting. Various other embodiments of a workpiece-assembly <NUM> and/or build plate <NUM> are contemplated which may also allow for the workpieces <NUM> to be secured with suitable positioning and alignment, all of which are within the spirit and scope of the present disclosure.

Now turning to <FIG>, exemplary methods of aligning a build plate <NUM> to coordinates of an additive manufacturing system <NUM> (<FIG>), exemplary methods of working on workpieces at multiple work stations (<FIG>), and exemplary methods of additively printing extension segments <NUM> on a plurality of workpieces <NUM> (<FIG>) will be described.

As shown in <FIG>, an exemplary method <NUM> of aligning a build plate <NUM> to coordinates of an additive manufacturing system <NUM> may include, at step <NUM>, placing a build plate <NUM> on a work station <NUM> having a build plate-receiving surface <NUM> and a lock-pin <NUM> extending from the build plate-receiving surface <NUM>. The lock-pin <NUM> may include a hollow pin body <NUM>, a piston <NUM> disposed within the hollow pin body <NUM> such that the piston <NUM> is axially movable from a retracted position <NUM> to an actuated position <NUM>, and a plurality of detents <NUM> that are radially extensible through respective ones of a plurality of detent-apertures <NUM> in the hollow pin body <NUM> responsive to the piston <NUM> having been axially moved to the actuated position <NUM>. The build plate <NUM> may include a socket <NUM> having an inside surface <NUM> defining an engagement surface <NUM> for the plurality of detents <NUM> to lockingly engage the lock-pin <NUM> with the socket <NUM>. The exemplary method <NUM> may further include, at step <NUM>, actuating the piston <NUM> so as to lockingly engage the lock-pin <NUM> with the socket <NUM>. The lock-pin <NUM> includes a flushing channel <NUM> configured to flush debris from the lock-pin <NUM>, and the exemplary method <NUM> may optionally include, at step <NUM>, flushing debris from the lock-pin <NUM>. The step <NUM> of flushing debris from the lock-pin <NUM> may be performed before, during, and/or after, step <NUM>. Additionally, or alternatively, step <NUM> may be performed before, during, and/or after, step <NUM>.

Now referring to <FIG>, an exemplary method <NUM> of working on workpieces at multiple work stations will be described. As shown in <FIG>, an exemplary method <NUM> may include, at step <NUM>, lockingly engaging a build plate <NUM> at a first work station <NUM>; at step <NUM>, performing a first work-step on a plurality of workpieces <NUM> secured to the build plate <NUM>; at step <NUM>, releasing the build plate <NUM> from the first work station <NUM>; at step <NUM>, lockingly engaging the build plate <NUM> at a second work station <NUM>; and at step <NUM>, performing a second work-step on the plurality of workpieces <NUM> secured to the build plate <NUM>. The first work station <NUM> may include a first lock-pin <NUM> extending from a first build plate-receiving surface <NUM>, and the build plate <NUM> may include a socket <NUM> configured to lockingly engage with the first lock-pin <NUM>. The second work station <NUM> may include a second lock-pin <NUM> extending from a second build plate-receiving surface <NUM>, and the socket <NUM> of the build plate <NUM> may be configured to lockingly engage with the second lock-pin <NUM>.

In some embodiments, at step <NUM>, the first work-step may include obtaining with a vision system <NUM>, one or more digital representations of a workpiece-interface <NUM> of each of the plurality of workpieces <NUM>. Additionally, or in the alternative, at step <NUM>, the second work-step may include additively printing on the workpiece-interfaces <NUM> of the plurality of workpieces <NUM>.

In other embodiments, at step <NUM>, the first work-step may include preparing a workpiece-interface <NUM> on the plurality of workpieces <NUM>. Additionally, or in the alternative, at step <NUM>, the second work-step may include obtaining with a vision system <NUM>, one or more digital representations of the workpiece-interfaces <NUM> of the plurality of workpieces <NUM>. Preparing a workpiece-interface <NUM> on the plurality of workpieces <NUM> may include subjecting workpieces <NUM> to a subtractive modification so as to provide a workpiece-interface <NUM> thereon. This may include cutting, grinding, machining, electrical-discharge machining, brushing, etching, polishing, or otherwise substantively modifying a workpiece <NUM> so as to provide a workpiece-interface <NUM> thereon. The subtractive modification may include removing a subtraction portion (not shown) so as to provide a workpiece-interface <NUM>. The subtractive modification may include removing at least a portion of a surface of the workpiece <NUM> that has been worn or damaged. For example, the workpiece <NUM> may include artifacts (not shown), such as microcracks, pits, abrasions, defects, foreign material, depositions, imperfections, and the like. Such artifacts may commonly appear on the top surface of a compressor or turbine blade as a result of the extreme conditions to which such blades are subjected. The subtractive modification may additionally or alternatively be performed so as to improve bonding between the workpiece <NUM> and an extension segment <NUM> additively printed thereon.

In still further embodiments, an exemplary method <NUM> may optionally include, at step <NUM>, releasing the build plate <NUM> from the second work station <NUM>; at step <NUM>, lockingly engaging the build plate <NUM> at a third work station <NUM>; and at step <NUM>, performing a third work-step on the plurality of workpieces <NUM> secured to the build plate <NUM>. The third work station <NUM> may include a third lock-pin <NUM> extending from a third build plate-receiving surface <NUM>, and the socket <NUM> of the build plate <NUM> may be configured to lockingly engage with the third lock-pin <NUM>. By way of example, the third work-step may include additively printing on the workpiece-interfaces <NUM> of the plurality of workpieces <NUM>.

Referring still to <FIG>, in some embodiments, the first lock-pin <NUM> may include a first flushing channel <NUM> configured to flush debris from the first lock-pin <NUM>, and an exemplary method <NUM> may optionally include, at step <NUM>, flushing debris from the first lock-pin <NUM> before, during, and/or after lockingly engaging the build plate <NUM> at the first work station <NUM> at step <NUM>. Additionally, or in the alternative, the second lock-pin <NUM> may include a second flushing channel <NUM> configured to flush debris from the second lock-pin <NUM>, and an exemplary method <NUM> may optionally include, at step <NUM>, flushing debris from the second lock-pin <NUM> before, during, and/or after lockingly engaging the build plate <NUM> at the second work station <NUM> at step <NUM>. Further additionally, or in the alternative, the third lock-pin <NUM> may include a third flushing channel <NUM> configured to flush debris from the third lock-pin <NUM>, and an exemplary method <NUM> may optionally include, at step <NUM>, flushing debris from the third lock-pin <NUM> before, during, and/or after lockingly engaging the build plate <NUM> at the third work station <NUM> at step <NUM>.

Now referring to <FIG>, an exemplary method <NUM> of additively printing extension segments <NUM> on a plurality of workpieces <NUM> will be described. As shown in <FIG>, an exemplary method <NUM> may include, at step <NUM>, lockingly engaging a build plate <NUM> on a first work station <NUM> associated with a vision system <NUM>, such as a vision system-work station <NUM>. The first work station <NUM> may have a first build plate-receiving surface <NUM> and a first lock-pin <NUM> extending from the first build plate-receiving surface <NUM>. The first lock-pin <NUM> may have a first plurality of radially extensible detents <NUM>. The build plate <NUM> may have a socket <NUM> with an inside surface <NUM> defining an engagement surface <NUM> for the first plurality of radially extensible detents <NUM> to lockingly engage the first lock-pin <NUM> with the socket <NUM>.

The exemplary method <NUM> may further include, at step <NUM>, obtaining with a vision system <NUM>, one or more digital representations of a workpiece-interface <NUM> of each of a plurality of workpieces <NUM> secured to the build plate <NUM>. The digital representations may be obtained using a vision system <NUM> that has one or more cameras <NUM> providing one or more fields of view <NUM> that include the workpiece-interface <NUM> of each of the plurality of workpieces <NUM> secured to the build plate <NUM>. The one or more cameras <NUM> may include a field of view <NUM> that includes all of the workpiece interfaces <NUM>, or the one or more cameras <NUM> may be moved, adjusted, articulates, or the like so as to bring various workpiece interfaces <NUM> into the field of view <NUM>.

Still referring to <FIG>, an exemplary method <NUM> may further include, at step <NUM>, releasing the build plate <NUM> from the first work station <NUM>, and at step <NUM>, lockingly engaging the build plate <NUM> on a second work station <NUM> associated with an additive manufacturing machine <NUM>, such as an additive manufacturing-work station <NUM>. The second work station <NUM> may have a second build plate-receiving surface <NUM> and a second lock-pin <NUM> extending from the second build plate-receiving surface <NUM>, such as an additive manufacturing machine-lock-pin <NUM>. The second lock-pin <NUM> may have a second plurality of radially extensible detents <NUM>. The inside surface <NUM> of the socket <NUM> of the build plate <NUM> may similarly define an engagement surface <NUM> for the second plurality of radially extensible detents <NUM> to lockingly engage the second lock-pin <NUM> with the socket <NUM>.

For example, a vision system-work station <NUM> including one or more vision system-lock-pins <NUM> may be coordinatedly configured with an additive manufacturing-work station <NUM> having one or more additive manufacturing machine-lock-pins <NUM>. In this way, a build plate <NUM> may be lockingly engaged with the build plate-receiving surface <NUM> of the vision system-work station <NUM> for purposes of obtaining with one or more digital representations of a workpiece-interface <NUM> of each of a plurality of workpieces <NUM> secured to the build plate <NUM>, and then the build plate <NUM> may be lockingly engaged with the build plate-receiving surface <NUM> of the additive manufacturing-work station <NUM> for purposes of additively printing extension segments <NUM> on the workpiece-interfaces <NUM> of the plurality of workpieces <NUM>. In some embodiments, the first lock-pin <NUM> may align the build plate <NUM> to vision system-coordinates when the first lock-pin <NUM> lockingly engages the engagement surface <NUM> of the build plate <NUM>. Additionally, or in the alternative, the second lock-pin <NUM> may align the build plate <NUM> to additive manufacturing machine-coordinates when the second lock-pin <NUM> lockingly engages the engagement surface <NUM> of the build plate <NUM>.

Further to the exemplary method <NUM> of additively printing extension segments <NUM> on a plurality of workpieces <NUM>, at step <NUM>, the method <NUM> may include transmitting to the additive manufacturing machine <NUM>, one or more print commands configured to additively print the plurality of extension segments <NUM>, and at step <NUM>, the method <NUM> may include additively printing the plurality of extension segments <NUM> on the workpiece-interfaces <NUM> of the plurality of workpieces <NUM>. The one or more print commands may be generated based at least in part on the one or more digital representations obtained using the vision system <NUM>, and the plurality of extension segments <NUM> may be additively printed with each respective one of the plurality of extension segments <NUM> being located on the workpiece-interface <NUM> of a corresponding respective one of the plurality of workpieces <NUM>.

Now referring to <FIG>, further features of an additive manufacturing system <NUM> will be described. As shown in <FIG>, an exemplary additive manufacturing system <NUM> may include a control system <NUM>. An exemplary control system <NUM> includes a controller <NUM> communicatively coupled with a vision system <NUM> and/or an additive manufacturing machine <NUM>. The controller <NUM> may also be communicatively coupled with a user interface <NUM> and/or a management system <NUM>.

The controller <NUM> may include one or more computing devices <NUM>, which may be located locally or remotely relative to the additive vision system <NUM> and/or the additive manufacturing machine <NUM>. The one or more computing devices <NUM> may include one or more processors <NUM> and one or more memory devices <NUM>. The one or more processors <NUM> may include any suitable processing device, such as a microprocessor, microcontroller, integrated circuit, logic device, and/or other suitable processing device. The one or more memory devices <NUM> may include one or more computer-readable media, including but not limited to non-transitory computer-readable media, RAM, ROM, hard drives, flash drives, and/or other memory devices.

The one or more memory devices <NUM> may store information accessible by the one or more processors <NUM>, including machine-executable instructions <NUM> that can be executed by the one or more processors <NUM>. The instructions <NUM> may include any set of instructions which when executed by the one or more processors <NUM> cause the one or more processors <NUM> to perform operations. In some embodiments, the instructions <NUM> may be configured to cause the one or more processors <NUM> to perform operations for which the controller <NUM> and/or the one or more computing devices <NUM> are configured. Such operations may include controlling the vision system <NUM> and/or the additive manufacturing machine <NUM>, including, for example, causing the vision system <NUM> to capture a digital representation of a field of view <NUM> that includes a workpiece-interface <NUM> of one or more workpieces <NUM>, generating one or more print commands based at least in part on the one or more digital representations of the one or more fields of view <NUM>, and causing the additive manufacturing machine <NUM> to additively print respective ones of the plurality of extension segments <NUM> on corresponding respective ones of the plurality of workpieces <NUM>. For example, such instructions <NUM> may include one or more print commands, which, when executed by an additive manufacturing machine <NUM>, cause an additive-manufacturing tool to be oriented with respect to a toolpath that includes a plurality of toolpath coordinates and to additively print at certain portions of the toolpath so as to additively print a layer of the plurality of extension segments <NUM>. The layer of the plurality of extension segments <NUM> may correspond to a slice of an extension segment-CAD model. Such operations may additionally or alternatively include calibrating an additive manufacturing system <NUM>.

Such operations may further additionally or alternatively include receiving inputs from the vision system <NUM>, the additive manufacturing machine <NUM>, the user interface <NUM>, and/or the management system <NUM>. Such operations may additionally or alternatively include controlling the vision system <NUM> and/or the additive manufacturing machine <NUM> based at least in part on the inputs. Such operations may be carried out according to control commands provided by a control model <NUM>. As examples, exemplary control models <NUM> may include one or more control models <NUM> configured to determine a workpiece-interface <NUM> of each of a plurality of workpieces <NUM> from one or more digital representations of one or more fields of view <NUM>; one or more control models <NUM> configured to determine and/or generate an extension segment-CAD model based at least in part on the one or more digital representations of the one or more fields of view <NUM>; and/or one or more control models <NUM> configured to slice an extension segment-CAD model into a plurality of slices and/or to determine or generate a toolpath and an additive printing area for each of the plurality of slices. The machine-executable instructions <NUM> can be software written in any suitable programming language or can be implemented in hardware. Additionally, and/or alternatively, the instructions <NUM> can be executed in logically and/or virtually separate threads on processors <NUM>.

The memory devices <NUM> may store data <NUM> accessible by the one or more processors <NUM>. The data <NUM> can include current or real-time data, past data, or a combination thereof. The data <NUM> may be stored in a data library <NUM>. As examples, the data <NUM> may include data associated with or generated by additive manufacturing system <NUM>, including data <NUM> associated with or generated by a controller <NUM>, the vision system <NUM>, the additive manufacturing machine <NUM>, the user interface <NUM>, the management system <NUM>, and/or a computing device <NUM>. The data <NUM> may also include other data sets, parameters, outputs, information, associated with an additive manufacturing system <NUM>, such as those associated with the vision system <NUM>, the additive manufacturing machine <NUM>, the user interface <NUM>, and/or the management system <NUM>.

The one or more computing devices <NUM> may also include a communication interface <NUM>, which may be used for communications with a communications network <NUM> via wired or wireless communication lines <NUM>. The communication interface <NUM> may include any suitable components for interfacing with one or more network(s), including for example, transmitters, receivers, ports, controllers, antennas, and/or other suitable components. The communication interface <NUM> may allow the computing device <NUM> to communicate with the vision system <NUM>, the additive manufacturing machine <NUM>. The communication network <NUM> may include, for example, a local area network (LAN), a wide area network (WAN), SATCOM network, VHF network, a HF network, a Wi-Fi network, a WiMAX network, a gatelink network, and/or any other suitable communications network for transmitting messages to and/or from the controller <NUM> across the communication lines <NUM>. The communication lines <NUM> of communication network <NUM> may include a data bus or a combination of wired and/or wireless communication links.

The communication interface <NUM> may additionally or alternatively allow the computing device <NUM> to communicate with a user interface <NUM> and/or a management system <NUM>. The management system <NUM>, which may include a server <NUM> and/or a data warehouse <NUM>. As an example, at least a portion of the data <NUM> may be stored in the data warehouse <NUM>, and the server <NUM> may be configured to transmit data <NUM> from the data warehouse <NUM> to the computing device <NUM>, and/or to receive data <NUM> from the computing device <NUM> and to store the received data <NUM> in the data warehouse <NUM> for further purposes. The server <NUM> and/or the data warehouse <NUM> may be implemented as part of a control system <NUM>.

Claim 1:
A build plate-clamping assembly (<NUM>), comprising:
a work station (<NUM>) having a build plate-receiving surface (<NUM>); and
a lock-pin (<NUM>) extending from the build plate-receiving surface (<NUM>) of the work station (<NUM>), the lock-pin (<NUM>) comprising:
a hollow pin body (<NUM>);
a piston (<NUM>) disposed within the hollow pin body (<NUM>), the piston (<NUM>) axially movable from a retracted position (<NUM>) to an actuated position (<NUM>); and
a plurality of detents (<NUM>), the plurality of detents (<NUM>) radially extensible through respective ones of a plurality of detent-apertures (<NUM>) in the hollow pin body (<NUM>) responsive to the piston (<NUM>) having been axially moved to the actuated position (<NUM>);
wherein the lock-pin (<NUM>) comprises a flushing channel (<NUM>) defining a pathway for a fluid (<NUM>) to flow from a fluid source (<NUM>) and discharge from the hollow pin body (<NUM>) so as to flush debris from the lock-pin (<NUM>).