Related Application(s)

The present application claims priority from and the benefit of U.S. Provisional Application Serial No. 63/017,750, filed April 30, 2020, the disclosure of which is hereby incorporated herein in its entirety.

Field of the Invention

The present invention concerns additive manufacturing, and particularly concerns methods, systems, and apparatus for applying and removing release films from additive manufacturing build platforms.

Background of the Invention

A group of additive manufacturing techniques sometimes referred to as "stereolithography" creates a three-dimensional object by the sequential polymerization of a light polymerizable resin. Such techniques may be "bottom-up" techniques, where light is projected into the resin on the bottom of the growing object through a light transmissive window, or "top-down" techniques, where light is projected onto the resin on top of the growing object, which is then immersed downward into the pool of resin.

The recent introduction of a more rapid stereolithography technique known as continuous liquid interface production ("CLIP"), coupled with the introduction of "dual cure" resins for additive manufacturing, has expanded the usefulness of stereolithography from prototyping to manufacturing (see, e.g., U.S. Patent Nos. 9,211,678; 9,205,601; and 9,216,546 to DeSimone et al.; and also in J. Tumbleston, D. Shirvanyants, N. Ermoshkin et ak, Continuous liquid interface production of 3D Objects, Science 347, 1349-1352 (2015); see also Roll and et ak, U.S. Patent Nos. 9,676,963; 9,453,142; and 9,598,606).

In additive manufacturing processes such as bottom-up stereolithography, the objects are formed on a (typically) planar surface of a build platform (see, for example, G. Dachs, Removable build platform for an additive manufacturing apparatus, PCT Application Publication No. WO 2020/069167). For higher volume production, it may be preferred to adhere a removable release film to the build platform, on which release film the objects are formed (see, for example, X. Gu, Adhesive sheet for securing 3d object to carrier platform and method of using same, PCT Application Publication No. WO 2018/011883). However, Guonly describes a hand tool for removing the sheet and does not provide applicators or removers that can conveniently apply or remove sheets to build platforms in a higher throughput, manufacturing, environment.

Applicators for the sign industry are described in U.S. Patents Nos. 6,102,096 and 6,406,582, PCT Application Publication No. WO 2014/088501, and in the 2012 Rollsroller Owner's Manual, but do not suggest how these applicators could be adapted to additive manufacturing, and do not provide for complementary removal of the applied film.

Summary of the Invention

An applicator apparatus for applying a release film to the planar build surface of an additive manufacturing build platform is described. The apparatus includes: (a) a chassis having a top plate; (b) at least one build platform alignment member on the top plate, the alignment member configured for positioning the build platform on the top plate with the planar build surface thereof facing upward; (c) a roller carrier connected to the chassis and configured with the top plate to pass over the planar build surface (e.g., by the roller carrier moving over a stationary top plate, or a top plate moving beneath a stationary roller carrier); and (d) a roller connected to the roller carrier and configured to press against a release film positioned on the planar build surface of the build platform.

An apparatus for removing a release film, or at least one additively manufactured object, adhered to the planar build surface of an additive manufacturing build platform is also described herein. The apparatus includes (a) a chassis having a top plate; (b) at least one build platform alignment member on the top plate, the alignment member configured for positioning the build platform on the top plate with the planar build surface thereof facing upward; (c) a blade carrier connected to the chassis and configured with the top plate to pass over the planar build surface (e.g., by the blade carrier moving over a stationary top plate, or atop plate moving beneath a stationary blade carrier); and (d) a blade connected to the blade carrier and configured, when a build platform is positioned on the top plate, to press against the planar build surface and scrape a release film or additively manufactured object adhered to the planar build surface off that surface. In some embodiments, the release film has one or more (e.g. a plurality) additively manufactured object(s) formed thereon by additive manufacturing, which can then be removed together from the planar build surface along with the release film. Apparatus for applying and removing such as described above and below can be combined together in integrated and/or automated ( e.g robotically assisted) additive manufacturing systems, as described further below.

While in some embodiments the apparatus for applying and removing are described herein as embodiments configured for hand operation, in other embodiments the apparatus can be embodied in configurations for automated operation and/or robotically assisted operation.

Brief Description of the Drawings

Figure 1 is a perspective view of one embodiment of an applicator apparatus as described further herein, without a build platform mounted thereon. The film aligner is in its up position.

Figure 2 is a perspective view of the applicator apparatus of Figure 1, with a build platform mounted thereon, and a release film adhered to the planar build surface of the build platform. The film aligner is in a partially lowered position.

Figure 3 is a lower, perspective, view of the apparatus of Figures 1 and 2, with the protective skirt removed to reveal additional components.

Figure 4 is a detailed view of a portion of Figure 3.

Figure 5 is a back side view of same portion of the apparatus of Figure 3 as shown in

Figure 4.

Figure 6 is a side view of the apparatus of Figures 1-5, showing the "figure eight" cam track.

Figure 7 is a bottom view of the apparatus of Figures 1-6, showing the rail to which, the roller carrier is movably connected via a carriage (hidden behind a crossbar).

Figure 8 is a perspective view of one embodiment of a remover apparatus as described herein, without a build platform mounted thereon.

Figure 9 is a perspective view of the remover apparatus of Figure 8, now with a build platform mounted thereon. The build platform has a release film adhered to the planar build surface thereof, with additively manufactured objects adhered to the release film.

Figure 10 is a lower perspective view of the apparatus of Figures 8 and 9, with the protective skirt removed.

Figure 11 is a bottom view of the apparatus of Figures 8-10, showing the rail to which, the blade carrier is movably connected via a carriage (again hidden behind the crossbar).

Figure 12 is a side perspective view of a portion of the apparatus of Figures 8-10, showing the path followed by the blade carrier lifter cam and follower over its cam track. Figure 13 is an additional side perspective view of a portion of the apparatus of Figures 8-10, showing the path followed by the blade guard lock cam and follower over its respective cam track.

Figure 14 is a lower rear perspective view of a portion of the apparatus of Figures 8- 13, showing the operation of the blade guard lock and the path of the blade guard.

Figure 15 schematically illustrates a coordinated method of additive manufacturing employing application and removal of a release film, as may be carried out with the apparatus of Figures 1-14.

Figure 16 schematically illustrates one embodiment of an additive manufacturing system by which methods as described in Figure 15 may be carried out.

The foregoing and other objects and aspects of the present invention are explained in greater detail in the drawings herein and the specification set forth below. The disclosures of all United States patent references cited herein are to he incorporated herein by reference.

Detailed Description of Illustrative Embodiments

The present invention is now described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art.

Like numbers refer to like elements throughout. In the figures, the thickness of certain lines, layers, components, elements, or features may be exaggerated for clarity. Where used, broken lines illustrate optional features or operations unless specified otherwise.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an" and "the" are intended to include plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements components and/or groups or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups or combinations thereof. As used herein, the term "and/or" includes any and all possible combinations or one or more of the associated listed items, as well as the lack of combinations when interpreted in the alternative ("or").

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and claims and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well-known functions or constructions may not be described in detail for brevity and/or clarity.

It will be understood that when an element is referred to as being "on," "attached" to, "connected" to, "coupled" with, "contacting," etc., another element, it can be directly on, attached to, connected to, coupled with and/or contacting the other element or intervening elements can also be present. In contrast, when an element is referred to as being, for example, "directly on," "directly attached" to, "directly connected" to, "directly coupled" with or "directly contacting" another element, there are no intervening elements present. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed "adjacent" another feature can have portions that overlap or underlie the adjacent feature.

Spatially relative terms, such as "under," "below," "lower," "over," "upper" and the like, may be used herein for ease of description to describe an element’s or feature’s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, elements described as "under" or "beneath" other elements or features would then be oriented "over" the other elements or features. Thus, the exemplary term "under" can encompass both an orientation of over and under. The device may otherwise be oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms "upwardly," "downwardly," "vertical," "horizontal" and the like are used herein for the purpose of explanation only, unless specifically indicated otherwise.

It will be understood that, although the terms first, second, etc., may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. Rather, these terms are only used to distinguish one element, component, region, layer and/or section, from another element, component, region, layer and/or section. Thus, a first element, component, region, layer or section discussed herein could be termed a second element, component, region, layer or section without departing from the teachings of the present invention. The sequence of operations (or steps) is not limited to the order presented in the claims or figures unless specifically indicated otherwise.

Build platforms (sometimes previously referred to as "carrier platforms") for additive manufacturing systems, methods and apparatus, including those with unique identifiers (such as NFC tags, RFID tags, bar codes, etc.) are associated therewith, are known and described in, for example, G. Dachs, Removable build platform for an additive manufacturing apparatus, PCT Application Publication No. WO 2020/069167; Horn et a!., Robotic additive manufacturing system U.8. Patent Application Publication No. 2020/0070421, and DeSimone et al, Integrated additive manufacturing systems incorporating a flxluring apparatus, U.S. Patent Application Publication No. 2020/0001536.

Release sheets for additive manufacturing apparatus build platforms are known and described in, for example, X. Gu, Adhesive sheet for securing 3d object to carrier platform and method of using same, PCT Application Publication No. WO 2018/11883.

1. APPLICATOR APPARTUS.

Figures 1-7 show a non-limiting embodiment of an applicator apparatus 20, for applying a release film 31 to a planar build surface of an additive manufacturing build platform 30. The applicator apparatus 20 includes: (a) a chassis having a top plate 21; (b) at least one build platform alignment member 25 on the top plate 21, the alignment member 25 configured for positioning the build platform 30 on the top plate 21 with the planar build surface thereof facing upward; (c) a roller carrier 22 connected to the chassis and configured with the top plate 21 to pass over the planar build surface (e.g., by the roller carrier 22 moving over a stationary top plate 21, or a top plate 21 moving beneath a stationary roller carrier 22); and (d) a roller 23 connected to the roller carrier 22 and configured to press against a release film 31 positioned on the planar build surface of the build platform 30. In some embodiments, a moving roller carrier 22 may be preferred, for example, with manually operated or desk-top embodiments. In some embodiments, a moving top plate 21 may be preferred, for example, in embodiments directed to automated or robotic environments.

In some embodiments, the applicator apparatus 20 may further include: (e) a lift assembly operatively associated with the roller 23. The lift assembly may be configured to switch between (i) a first position in which the roller 23 is pressed towards and against the release film 31 positioned on the planar build surface of the build platform 30 when the roller carrier 22 is positioned over at least a portion of the build surface, and (ii) a second position in which the roller 23 is lifted away from the planar build surface of the build platform 30 when the roller carrier 22 is spaced laterally apart from the build platform 30.

The alignment member can be in the form of comer stops 25 as shown, could be in the form of at least one platform block that fits into the reverse side of the build platform 30 (as shown in connection with the remover apparatus 120 discussed below), or could be in any other form such as a clamp, post, pin, or the like. Leveler feet 32 can be connected to the chassis, and a protective skirt 27 can be connected to the chassis to shield components beneath the top plate 21.

In the illustrated embodiment, the lift assembly is in the first (raised) position as the roller 23 is moved from left to right until it reaches approximately the position of line a-a in Figure 2, at which point the roller 23 is switched to the first (lowered, film-contact) position for the remainder of its travel across the build platform 30 from left to right. Upon reaching the far right position, off the build platform 30, the lift assembly is then switched to the second (raised) position as the roller 23 is moved from right to left until it reaches approximately the position of line a -a' in Figure 2, at which point the roller 23 is switched to the first (lowered, film-contact) position for the remainder of its travel across the build platform 30 from right to left.

Thus, in a preferred embodiment, while in the first position, the roller 23 is pressed against the release film 31 positioned on the planar build surface of the build platform 30 when the roller carrier 22 is positioned over only a portion of the build surface (preferably a trailing portion) in both the forward and reverse directions. This lack of contact, or lifting, during the leading portion position, is helpful to allowing the operator to reach beneath the film 31, when initially laid down or partially applied, to fold and then remove a backer sheet that may be between the film 31 and the build surface 30. For films that do not require the removal of a backing (such as a release film 31 with a pressure-sensitive adhesive), a lifting mechanism may not be required.

Lines a-a and a' -a' are also shown in Figure 6, discussed below, in connection with the "figure eight" track 51 which effects this switching in the illustrated embodiment. However, it should be noted that switching of the roller 23 from its contact to non-contact positions can be achieved with any of a variety of other lift assemblies, such as an appropriately configured four bar linkage, or any other electromagnetic (piston or motor) pneumatic, piezoelectric, hydraulic, or mechanical lifter, operatively associated with a switch such as an optical, electrical, magnetic, piezoelectric, or mechanical switch.

In the illustrated embodiment, and as best seen in Figures 3-6, the switching assembly may comprise a cam track 51 (specifically, a "figure eight" cam track 51) connected to the chassis, and the lifting component may comprise a cam roller 41, piston 41a connected to the cam roller 41, and a follower 42 (together forming a cam and follower assembly) that are connected to the roller carrier 22, with the cam roller 41 operatively associated with the cam track 51 and the follower 42 operatively connected to the roller 23. Switching is determined by the position of the cam roller 41 in the figure eight track 51 as the roller carrier 22 is moved back and forth over the build platform 30, with the path of the cam roller 41 being shown by the dotted line and arrows in Figure 6.

The lift assembly is preferably configured so that (i) the roller 23 vertically floats (in the illustrated embodiment, on shoulder bolts 44 through linear bearings 45 in follower 42 while the lift assembly is in the first position, with the roller 23 weighted sufficiently to press the roller 23 against the release film 31; and/or (ii) the apparatus 20 further comprises a compression or tension element operatively associated with the roller 23 and configured to press the roller 23 against the release film 31 while the lift assembly is its first position. In the illustrated embodiment, the piston 41a pushes the follower 42 upwards to lift the roller 23, but when the piston 41a is in a down position (as determined by its position in figure eight track 51, then the follower 42 is pulled downward, both by its weight and by tension springs 43 (which are secured on their upper end to the follower 42, and on their lower end to a fixed position in the roller carrier 22) to press it against the release film 31. Downward travel of the piston 41a may be limited by compression springs 47, and ownward travel of the follower 42 may be limited by hard stop 46. Compression springs 47 are compressed when the roller 23 travels downward on the left and right tail segments 51a of the figure eight track 51, so that the cam roller 41 rebounds to the upper path of the figure eight track 51 as the roller carrier 22 begins its next pass over the build platform 30.

While a specific mechanism is illustrated above for completeness of disclosure, those skilled in the art will appreciate that numerous other mechanisms can be employed in the alternative. For example, the compression or tension elements could be pneumatic or hydraulic cylinders, motors, magnetic elements, etc, particularly for automated or robotically implemented embodiments, as discussed further below.

The apparatus preferably includes a film aligner 24 operatively associated with (e.g., pivotally connected to) the top plate 21. The film aligner 24 may be switchable between: (i) a first position below the planar build surface of the build platform 30 positioned on the top plate 21, and (ii) a second position adjacent to and aligned with the build surface of the build platform 30 positioned on the top plate 21. In the second position, an alignment surface 28 is presented, against which the release film 31 can be abutted for initial alignment with the build surface 30. Again, while a pivotal connection is illustrated, numerous alternative structures can be employed, including connections in which the aligner twists, turns, or slides, sideways, moves up or down, or is simply detachable. And the film aligner 24 itself could be spring activated or automated with any suitable drive and switch assembly such as described above with respect to lift mechanisms.

In the illustrated embodiment, the chassis has a pair of opposite side portions and the roller carrier 22 comprises a pair of opposing upright arms 22a with the roller 23 connected therebetween, each upright arm 22a movably connected to the chassis along one of the opposite side portions ( e.g ., through the top plate 21, in an "inboard" position, as shown, or along side the top plate 21 in an "outboard" position). When a cam track 51 is used as the switching mechanism, and a cam and follower assembly is used as the lift assembly, the cam track 51 comprises a pair of cam tracks, each positioned along one of the chassis opposite side portions, as shown, and the cam and follower assembly comprises a pair of cam and follower assemblies, each connected to one of the opposing upright arms 22a, as shown.

Connection of the roller carrier 22 to the chassis can be by any suitable means. In the illustrative embodiment, the chassis has a rail 65 connected thereto, and the roller carrier 22 has a carriage (concealed behind crosspiece 35 connected thereto (through spacer 34 in the illustrative embodiment), with the carriage movably connected to the rail 65 with travel limited by bumpers 33, all in accordance with standard techniques.

In the illustrative embodiment, the roller carrier 22 has a handle 22b connected thereto, or formed thereon, for manually advancing the roller carrier 22 over the planar build surface of the build platform 30. While manual advancing is shown by sliding, note that in alternative embodiments (such as in the case of the remover apparatus discussed below), manual advancing can be by means of a crank and screw, lever, rack and pinion, or the like. In addition, advancing can be automated or power-assisted, such as by including an electric, pneumatic, or hydraulic drive, or the like.

Where the build platform 30 has a unique identifier associated therewith, the applicator platform may likewise have a corresponding unique identifier reader operatively associated therewith, such as for maintaining a digital record of the manufacturing process for particular objects, in an integrated additive manufacturing system (discussed further below). Once the build platform 30 has the release film 31 affixed thereto with an apparatus 20 such as described above, it can then be installed into an additive manufacturing apparatus, for production of at least one object 201 by additive manufacturing thereon, as described below.

2. RESINS AND ADDITIVE MANUFACTURING STEPS.

Techniques for producing objects from resins by additive manufacturing are known. Suitable techniques include bottom-up and top-down additive manufacturing, generally known as stereolithography. Such methods are known and described in, for example, U.S. Patent No. 5,236,637 to Hull, U.S. Patent Nos. 5,391,072 and 5,529,473 to Lawton, U.S. Patent No. 7,438,846 to John, U.S. Patent No. 7,892,474 to Shkolnik, U.S. Patent No. 8,110,135 to El- Siblani, U.S. Patent Application Publication No. 2013/0292862 to Joyce, and U.S. Patent Application Publication No. 2013/0295212 to Chen et al. The disclosures of these patents and applications are incorporated by reference herein in their entirety.

In some embodiments, the additive manufacturing step is carried out by one of the family of methods sometimes referred to as as continuous liquid interface production ("CLIP"). CLIP is known and described in, for example, U.S. Patent Nos. 9,211,678; 9,205,601; 9,216,546; and others; in J. Tumbleston et al., Continuous liquid interface production of 3D Objects, Science 347, 1349-1352 (2015); and in R. Janusziewcz et al., Layerless fabrication with continuous liquid interface production, Proc. Natl. Acad. Sci. USA 113, 11703-11708 (October 18, 2016). Other examples of methods and apparatus for carrying out particular embodiments of CLIP include, but are not limited to: Batchelder et al., U.S. Patent Application Publication No. 2017/0129169 (May 11, 2017); Sun and Lichkus, U.S. Patent Application Publication No. 2016/0288376 (Oct. 6, 2016); Willis et al., U.S. Patent Application Publication No. 2015/0360419 (Dec. 17, 2015); Lin et al., U.S. Patent Application Publication No. 2015/0331402 (Nov. 19, 2015); D. Castanon, U.S. Patent Application Publication No. 2017/0129167 (May 11, 2017). B. Feller, U.S. Patent Application Publication No. 2018/0243976 (Aug 30, 2018); M. Panzer and J. Tumbleston, U.S. Patent Application Publication No. 2018/0126630 (May 10, 2018); K. Willis and B. Adzima, U.S. Patent Application Publication No. 2018/0290374 (Oct. 11, 2018); L. Robeson et al., PCT Application Publication No. WO 2015/164234 (see also U.S. Patent Nos. 10,259,171 and 10,434,706); and C. Mirkin et al., PCT Application Publication No. WO 2017/210298 (see also U.S. Patent Application Publication No. 2019/0160733). In some embodiments, dual cure resins can be used for carrying out the present invention. Such resins are known and described in, for example, U.S. Patent Nos. 9,676,963; 9,453,142; and 9,598,606 to Rolland et al. Particular examples of suitable dual cure resins include, but are not limited to, Carbon Inc. medical polyurethane, elastomeric polyurethane, rigid polyurethane, flexible polyurethane, cyanate ester, epoxy, and silicone dual cure resins, all available from Carbon, Inc., 1089 Mills Way, Redwood City, California 94063, USA.

Once objects 201 are produced on the film-coated surface of the build platform 30, the objects 201 can be cleaned, such as by washing, blowing, centrifugal separation, or any other suitable means. Additional curing, such as further light exposure for a single cure resin, or exposure to another mode of curing such as moisture, heat, microwave irradiation, or a combination thereof for a dual cure resin, can be carried out while the objects 201 remain on the build platform 30, or after their removal from the build platform 30. Removal of film 31 and object(s) 201 from the build platform 30 can be carried out as described below.

3. REMOVER APPARATUS.

Figures 8-14 show a non-limiting embodiment of a remover apparatus 120 for removing a release film 31, or additively manufactured object(s) 201, adhered to a planar build surface of an additive manufacturing build platform 30. The additively manufactured objects 201 may be adhered to the release film 31 as shown, or in some embodiments where a release film 31 is not laid down, the additively manufactured objects 201 may be adhered directly to the planar build surface 30. In either situation, the apparatus 120 may include: (a) a chassis having a top plate 121; (b) at least one build platform alignment member (such as an insertion block 125 on the top plate 121, the alignment member 125 configured for positioning the build platform 30 on the top plate 121 with the planar build surface thereof facing upward; (c) a blade carrier 122 connected to the chassis with the top plate 121 and configured to pass over the planar build surface of the build platform ( e.g ., by the blade carrier 122 moving over a stationary top plate 121, or a top plate 121 moving beneath a stationary blade carrier 122); and (d) a blade 128 connected to the blade carrier 122 and configured, when the build platform 30 is positioned on the top plate 121, to press against the planar build surface and scrape the release film 31, or additively manufactured object 201, adhered to the planar build surface off that surface. Similar to the roller carrier 22 discussed above, in some embodiments, a moving blade carrier 122 may be preferred, for example, with manually operated or desk-top embodiments. In some embodiments, a moving top plate 121 may be preferred, for example, in embodiments directed to automated or robotic environments.

In some embodiments, the apparatus 120 may further include: (e) a lift assembly operably associated with the blade carrier 122, the lift assembly configured to: (i) press the blade 128 against the planar build surface of the build platform 30 when the blade carrier 122 is advanced towards the planar build surface, and (ii) lift the blade 128 away from the planar build surface of the build platform 30 when the blade carrier 122 is retracted from the planar build surface 30.

Leveler feet 132 may be connected to the chassis as shown in Figure 10, and a protective skirt 127 connected to the chassis to shield components under the top plate 121, in like manner as described in connection with the applicator apparatus 20 above.

In some embodiments, the lift assembly is configured to lower the blade 128 onto the planar build surface at a position between the leading edge of the build platform 30, and the leading edge of the film 31 adhered to that build platform 30, for example, at a location indicated by line b-b in Figure 9. This can aide in preventing the blade 128 from colliding with the side wall of the build platform 30.

While a lift assembly may not be required if there is a leading ramp on the build platform 30 (although a component to press the blade 128 against the build surface would still be preferable to include), or a leading ramp positioned on the top plate 121 immediately in front of, and adjacent to, the leading edge of the build platform 30, a lift assembly such as in the illustrated embodiment is currently preferred. In general, such a lift assembly can include a lifting component operatively associated with the blade carrier 122, and a switching assembly operatively associated with the lifting component (and in some embodiments operably associated with the chassis, such as with cam track 151, as discussed below). Any suitable lifting component can be utilized, such as an electromagnetic (piston or motor) pneumatic, piezoelectric, hydraulic, or mechanical lifting component. Similarly, any suitable switching assembly can be employed, including optical, electrical, magnetic, piezoelectric, and mechanical switching assemblies. Note that, in embodiments where the lifting component is a four bar linkage connected between the chassis and the blade 128 or blade carrier 122, a switch may not be required where the bars are dimensioned to raise and lower the blade/blade carrier 128/122 in the appropriate location.

In the illustrated embodiment, the switching assembly comprises a lifter cam track 151 connected to the chassis; and the lifting component comprises a cam and follower assembly connected to the blade carrier 122 (specifically, roller cam 141 connected to blade lifter 142 which serves as the follower), with the roller cam 141 operatively associated with the lifter cam track 151 (specifically, by travelling along path a-a'). and the with the lifter/follower 142 operatively connected to the blade carrier 122. As can best be seen in Figure 12, the blade lifter 142 pushes against the blade carrier 122, which rotates on a pair of pivots 122b between the pair of upright arms 122a and lifts the blade carrier 122 up and down along path c-c'.

In some embodiments, the remover apparatus 120 includes a compression or tension element operatively associated with the blade carrier 122 and configured to press the blade 128 against the planar build surface while the lift assembly is in the first position (currently preferred) and/or the lift assembly is configured such that the blade carrier 122 vertically floats while the lift assembly is in the first position, with the blade carrier 122 weighted sufficiently to press the blade 128 against the planar build surface. Compression or tension elements could be springs, pneumatic or hydraulic cylinders, motors, magnetic elements, and the like, but in the illustrated embodiment is implemented as a tension spring 143, surrounding floating rod 143a. When a lift assembly is not included ( e.g ., due to the inclusion of a ramp as described above), then a compression or tension element may simply be opratively associated with a blade carrier 122.

In some embodiments, as a safety feature, the apparatus includes a blade guard 129 operatively associated with the blade 128 (e.g., pivotally connected to the blade carrier 122), with the blade guard 129 switchable on the blade 128 approaching a position immediately adjacent to, or contacting, the build platform 30 positioned on the top plate 121, between: (i) a first position in which the blade 128 is covered; to (ii) a second position in which the blade 128 is uncovered. In the illustrated embodiment the blade guard 129 is pivotally connected to the blade carrier 122, and swings down and back on guard arms 129a along paths g-g' and h-h' in Figure 14 when bumper portions 129b contacting the leading edge of the build platform 30. In other embodiments, the blade guard 129 could slide sideways, move up or down, or simply be made detachable. And as with other features described herein above, the blade guard 129 could be automated with drive and switch assemblies, like the lifting assemblies and switch assemblies described for the blade carrier 122 above.

In some embodiments, the remover apparatus 120 may further include a blade guard lock assembly operably associated with the blade guard 129, the lock assembly configured to fix the blade guard 129 in the first position until the blade 128 approaches a position immediately adjacent the build platform 30. As in other components, the lock can be implemented in a variety of ways, including as electromagnetic (piston or motor) pneumatic, hydraulic, piezoelectric, or mechanical locks, with an associated switch such as an optical, electrical, magnetic, piezoelectric, or mechanical switch. A mechanical lock and switch, implemented with a cam with a follower and cam track, is currently preferred. In the illustrated embodiment, and as shown in Figures 13-14, a cam track 171 provides a path e-e' for cam 172. Cam 172 is connected to guard stop 173 through rotatable guard stop control rod 174, which is biased to its forward, locking, position against guard arm 129b by spring 175. When the carrier assembly advances from position d-d to position d'-d' (for the rotatable rod) then the cam 172 is rotated by cam track 171, which in turn rotates guard stop 173 back along path f-f to its unlocked position, freeing guard arm 129b and allowing it, and the blade guard 129, to rotate away from the blade 128 as described above.

Returning to the general architecture of some embodiments, the chassis can have a pair of opposite side portions, and the blade carrier 122 can have a pair of opposing upright arms 122a, with the blade 128 connected therebetween. Each upright arm can 122a be movably connected to the chassis along one of the opposite side portions. As with the applicator apparatus 20, the upright arms 122a can be positioned inboard as shown, or outboard. When where the lifter assembly for the blade carrier 122 (and likewise also for the blade lock) is a cam track, cam and follower, they can, as in the illustrated embodiment, comprise a pair of cam tracks, each positioned along one of the chassis opposite side portions; and a pair of cam and follower assemblies, each connected to one of the opposing upright arms 122a.

In the illustrated embodiment, and as best seen in Figure 11, connection of the blade carrier 122 to the chassis is made through a rail 155 connected to the chassis, which is in turn connected to a carriage movable on the rail 155, in accordance with known techniques. The carriage is connected to the blade carrier 122 through a spacer and crossbar 135, as in the applicator apparatus 20 described above. While the applicator apparatus 20 has a slidable roller carrier 22, the blade carrier 122 has a crank 126 and associated drive assembly 126a ( e.g ., a drive gear connected to the crank, and a screw, worm, or rack associated with the rail), to aid in manually advancing the blade carrier 122 over the planar build surface of the build platform 30. While such a manual crank is currently preferred, this advancing mechanism can again be automated with an electric, pneumatic, or hydraulic drive, or the like, as for the applicator apparatus discussed above.

For integrated additive manufacturing systems such as discussed below, the build platform 30 can have a unique identifier (e.g., an NFC tag) connected thereto, and the remover apparatus 120 can have a corresponding unique identifier reader operatively associated therewith, in accordance with known techniques, for maintaining the digital record of the manufacturing process for the particular objects 201 made on and currently carried on that build platform 30.

4. METHODS AND SYSTEMS.

Figure 15 schematically illustrates a general method of additive manufacturing, including a centrifugal separation or "spin cleaning" step. The method incorporates release film application onto a build platform 30 (with an applicator apparatus 20 such as described herein), production of objects 201 on that release film/build platform 31/30, cleaning of the objects 201 by centrifugal separation shile on that release film/build platform 31/30, and then subsequent removal of objects 201 and release film 31 from the build platform 30 (with a remover apparatus 120 such as as described herein). Additional steps such as further curing (e.g., by flood curing with light for single cure resins, baking or other curing means for dual cure resins, etc.) can be implemented as desired in accordance with known techniques.

In overview, such a method includes at least the steps of: (a) applying a release film to the build surface of the build platform (Block 201); (b) producing at least one object on the release film from a light polymerizable resin while the build platform is engaged in an additive manufacturing apparatus (Block 202); (c) centrifugally separating (i.e., "spin cleaning") residual resin from the at least one object while the object remains on the release film and build platform (Block 203); and then (d) separating the object and the release film from the build platform (Block 205). In some cases, depending on the particular resin used, the method may further include further curing the object (e.g., by a single cure or dual cure process), before (Block 204) or after (not shown) the separating step (Block 205).

The appling step may be carried out by pressing a roller against the release film on a portion of the build surface in a first pass of the roller across the build surface in a first direction, and then pressing a roller against the release film on a portion of the build surface in a second pass of the roller across the build surface in an opposite direction from the first direction (preferably permitting folding and removal of a backer sheet on the release film otherwise between the release film and the build surface). In some embodiments, this step is carried out with an apparatus comprising a top plate and a roller carrier, with the build platform removably mounted on the top plate, the roller connected to the roller carrier, and the roller carrier and the top plate operatively associated with one another. Examples of suitable apparatus are described above, or variations thereof that will be apparent to those skilled in the art. Centrifugal separation may be carried out with any suitable apparatus, including but not limited to that described in M. Murillo and G. Dachs, Resin extractor for additive manufacturing, PCT Application Publication No. WO 2019/209732.

The separating step may be carried out by pressing an elongate blade against the planar build surface and scraping the release film (and additively manufactured object adhered thereto) off that surface with the blade (preferably by progressively passing the blade frome one side of the build surface to the other). In some embodiments, this step is carried out with a remover apparatus comprising a top plate and a blade carrier, with the build platform removably mounted on the top plate, the blade connected to the blade carrier, and the blade carrier and the top plate operatively associated with one another. Examples of suitable apparatus are described above, or variations thereof that will be apparent to those skilled in the art.

Figure 16 schematically illustrates a non-limiting example of a system by which such methods may be carried out. In general, such a system includes at least: (a) the applicator apparatus 20, 302 such as described herein, and (b) a remover apparatus 120, 305 such as described herein, configured to remove the release film 31 from the same surface of the additive manufacturing build platform 30 to which the release film 31 is applied by the applicator apparatus 20, 302,

In some embodiments (and as illustrated) the system further includes: (c) at least one, or a plurality of, additive manufacturing machines 303 (e.g., a bottom-up stereolithography apparatus such as a CLIP apparatus), and optionally (but in some embodiments preferably): (d) a robot 307 operatively associated with the additive manufacturing machine(s), the applicator apparatus 20, 302, and the remover apparatus 120, 305 and configured to transfer the build platform 30 therebetween. The robot 307 will usually be equipped with an end effector 307a configured to releasably engage the particular build platform 30 design implemented in the system.

Additional optional, but sometimes preferred, components of the system may include one or more of: (e) a build platform supply 301 operatively associated with the robot 307 (e.g., configured to store a plurality of build platforms ready to have a release film applied thereto); (1) a cleaner such as a centrifugal separator 304 as shown, or a washer, or blower, or combination thereof, operatively associated with the robot 307 (e.g., configured to receive one or more build platforms 30 having additively manufactured objects 201 formed thereon, for centrifugal separation of resin from the objects 201; (g) a build platform buffer station 306 operatively associated with the robot 307 (e.g., configured to store a plurality of build platforms 30 to which a release film 31 has been applied, and on which additively manufactured objects 201 have been formed thereon); and (h) optionally, at least one additional processing apparatus operatively associated with the robot 307 (e.g., a light flood cure station, an oven for implementing a second cure, a fixturing station, a support cutting or removal station, etc.).

Controller 308 and other features of the foregoing systems may be implemented in accordance with known techniques such as described in Horn et al., Robotic additive manufacturing system, U.S. Patent Application Publication No. 2020/0070421, DeSimone et al., Integrated additive manufacturing systems incorporating a fixturing apparatus, U.S. Patent Application Publication No. 2020/0001536, and variations thereof that will be apparent to those skilled in the art based upon the additional methods and apparatus described herein.

The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. The invention is defined by the following claims, with equivalents of the claims to be included therein.