Patent ID: 12246485

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are set forth by way of examples in order to provide a thorough understanding of the relevant teachings. It will be apparent to persons of ordinary skill, upon reading this description, that various aspects can be practiced without such details. In other instances, well known methods, procedures, components, and/or circuitry have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present teachings.

Current 3D printing systems present a technical problem because blades used to render the deposited powder uniform over a substrate may generate sheer forces that may prevent or hinder the printing of thin layers of powder, e.g., in the range of 100 μm. Furthermore, rollers used to compact the deposited powders also introduce sheer forces that may prevent or hinder the uniform printing of thin layers of powder. This problem also applies to powder deposited in a powder bed. Accordingly, in the following description, the term “substrate” may include a layer being provided by a powder bed.

To address these technical problems and more, in an example, this description provides a technical solution allowing for uniform powder deposition by using a powder feeder configured as an adjustable blade in conjunction with a counter-rotating roller positioned at a desired distance from the powder feeder. To further address the above technical problems, in another example, this description provides another technical solution independently adjusting the gap between the powder feeder and the surface of the substrate, and the gap between the counter-rotating roller and the surface of the substrate.

Various implementations include a print station of a three-dimensional (“3D”) printing apparatus, and method of 3D printing, the print station including a substrate configured to hold a printed object, the substrate having a longitudinal axis, and a print system over the substrate, the print system including a powder feeder device having a blade-shaped end, and a powder uniformization device located at a distance from the powder feeder device along a direction parallel to the longitudinal axis.

Various implementations include a powder deposition arrangement configured to facilitate uniform powder deposition of thin layers, where the powder is fed by a powder feeder that includes an adjustable blade, and the powder deposition arrangement also includes a counter-rotating roller located at a given distance from the powder feeder and used to compact the powder material during the process of 3D printing. In addition, the gap between the powder feeder and the substrate (feeder gap) may be adjustable to increase the quality of the powder deposition. The gap between the powder feeder and the surface of the substrate defines the quality of the deposition by, e.g., minimizing the compaction of the powder. As another example, the gap between the counter-rotating roller and the substrate (roller gap) is also adjustable to a desired value in order to control the printed thickness as well as quality of the thin layer deposition during the process of 3D printing, the roller gap being independently adjustable from the feeder gap. For example, the roller gap may define the final thickness of the printed layer, while, as discussed above, the powder feeder gap may define the quality of the deposition.

FIG.1schematically depicts a print station100and an assembly apparatus81with a continuous substrate. In embodiments, a print station100includes a printing system1and a substrate10. As will be discussed below, the printing system1includes a dispensing device20, a compaction device30, a binder printing device40, a fixing device50and a fluidized materials removal device60. As shown inFIG.1, the print station100can include a carrier device12. In some implementations, the carrier device12can include a conveyor configured to transport or move materials from a first position to a second position. The conveyor can include a belt and two rotating elements15, configured to rotate in the same direction to advance the belt in a certain direction. The carrier device12can have a distal end and a proximal end. The carrier device12can transport a substrate10from the distal end to the proximal end. The substrate10can be positioned by the two rotating elements15to a location where a transfer device76can transport a printed layer (not shown) to a build substrate80in the assembly apparatus81.

At the distal end of the carrier device12, a dispensing device20can be provided. The dispensing device20can simply be a dispenser configured to dispense fluidized material, e.g., a flowable powder. The dispensing device20can include a materials storage21and a dispensing controller22. The dispensing controller22can be configured to meter an amount of fluidized material deposited onto the substrate10. The dispensing controller22can also be configured to precisely control the uniformity of the deposited fluidized material.

Near the distal end of the carrier device12, a compaction device30can be provided. In some implementations, the compaction device30can include a roller, made up of a hardened metal material designed as a cylindrical tube. In some implementations, the compaction device30can be configured to compact a fluidized material to a high density of at least 40% of the theoretical density of the fluidized material. The compaction device30rotates in the direction opposing the direction of powder distribution from right to left, i.e., in a counter-clockwise direction opposing the spreading direction of the deposited powder layer when the substrate10moves from right to left while the dispensing device20and the compaction device30are static or not movable, as illustrated inFIG.1.

Near the distal end of the carrier device12, a binder printing device40can be provided. The binder printing device40can be configured to deposit a liquid binding material to fix a precise pattern into the fluidized material. The precise pattern can be fixed into the fluidized material by binding the fluidized material into a connected and robust mass. In some implementations, the binder printing device40can be an ink jet type print head under direct control of a computer (not shown).

Near the center of the carrier device12, a fixing device50can be provided. The fixing device50can be configured to solidify the liquid binding material, thus fixing the fluidized material exposed to the liquid binding material in a robust solid pattern. The fixing device50can be a source of radiant energy that may interact with the liquid binding material to cause it to become solid. In some implementations, the radiant energy can be IR radiation, UV radiation, electron beam, or other known radiation types. It should be understood the fixing device50does not need to be limited to the disclosed radiation types, as this list is presented for exemplary implementations and not intended to be exhaustive. Alternatively, the fixing device50can include a device for dispersing a reactive agent configured to react with the liquid binding material and the fluidized material to convert the fluidized material to a robust mass.

A fluidized materials removal device60can be provided downstream from the fixing device50. The fluidized materials removal device60can be configured to remove all of the fluidized material deposited and compacted onto the substrate10. The fluidized materials removal device60can remove the fluidized material deposited and compacted onto the substrate, but not fixed in place by the liquid binder material.

A transfer device76can be implemented downstream from the fluidized materials removal device60in the assembly apparatus81. The transfer device76can be configured to move a printed layer (not shown) from the substrate10. The printed layer can be moved from the substrate10to a build substrate80, or to the top of a stack of previously positioned layers91. The transfer device76can also include a pick-up assembly. The pick-up assembly can include an attachment device71configured to remove a printed layer from the substrate10. The attachment device71can include a vacuum device or an adhesive device to overcome the force holding the printed layer to the substrate10. The transfer device76may also include a translation device75configured to move the printed layer from the substrate10to the assembly apparatus81.

The elevator device90is configured to maintain the level of the top of the stack of previously positioned layers91. In an implementation, the elevator device90can include a linear motor device.

FIG.2illustrates a schematic representation of a print station with a continuous substrate for depositing thin layers of powder on a substrate, in accordance with various example implementations. With reference toFIG.1, the printing system210may correspond to, e.g., the combination of the dispensing device20and the compaction device30. InFIG.2, the print station200includes a support220corresponding to the carrier device12and a printing system210. The printing system210may be movable while the support220may be fixed, or the printing system210may be fixed while the support220is movable. The printing system210may include a top support230, an adjustable roller240configured to decrease or minimize non-uniform deposition, and a powder feeder250. The printing system210may also include a roller cleaner260to clean the roller240of any residual powder that may remain thereon and that may contaminate the roller240.

In operation, the powder is provided by the powder feeder250while the printing system210is moving from right to left relatively to the support220which remains stationary, or the support220is moving from left to right relatively to the printing system210which remains stationary. Accordingly, when the powder is provided by the powder feeder250, the powder is subsequently submitted to the rotating action of the roller240. For example, the roller240is a counter-rotating roller, i.e., the roller240rotates in a direction245that is opposite to a direction of the movement of powder feeder250or the direction of the spreading of the deposited powder layer. The roller240agitates the powder after the powder is deposited on the substrate270. Accordingly, the powder that is provided by the powder feeder250is uniformized by the action of the roller240.

The roller240also applies a pressure to the powder after the powder is deposited on the substrate270. Accordingly, the powder that is provided by the powder feeder250is uniformized by the action of the roller240. The roller240may be installed with an adjustable angle so that the accumulated powder may be released behind the roller.

FIG.3Aillustrates a portion of a print system300including a powder feeder350and a counter-rotating roller340, in accordance with various example implementations. With reference toFIG.1, the print system300may correspond to, e.g., the combination of the dispensing device20and the compaction device30. Further, a print station may include the print system300and the substrate370. In various implementations, the print system300includes a powder feeder350, and the powder feeder350has a blade375integrated or included therein, so that when the powder exits the powder feeder350at the blade375located at the exit point of the powder feeder350, the powder is flattened and at least partially uniformized by the blade375.FIG.3Cprovides an illustration of the blade375. For example, the blade375ensures that the thickness of the powder that is deposited by the powder feeder350remains substantially the same. In addition, for example, a counter-rotating roller340is positioned at a given distance from the blade375, the counter-rotating roller340further planarizing and uniformizing the powder that exits the powder feeder350at the blade375. For example, the counter-rotating roller340may enable a uniform deposition of less flowable powders. The blade375may ensure that the thickness of the powder that is deposited by the powder feeder350remains substantially the same as it approaches the counter-rotating roller340. As a result, powder accumulation in front of the counter-rotating roller340may be avoided or reduced.

The powder feeder350may also ensure the ability to maintain and/or reduce the sheer forces applied to the printed powder during powder deposition, and may thus allow the printing of thin layers, e.g., in the range of 100 μm, on a substrate370. The powder feeder350, which includes the blade375, may have an adjustment arrangement configured to adjust the gap between the powder feeder350/blade375and a surface of the substrate370. The counter-rotating roller340may also independently have an adjustment arrangement configured to adjust the gap between the counter-rotating roller340and the surface of the substrate370.

In various implementations, the print system300may further include a roller cleaner380configured to clean the counter-rotating roller340. For example, the roller cleaner380can remove unwanted powder particles that may remain on the counter-rotating roller340after the counter-rotating roller340distributed the powder. In addition, as the print system300may be movable with respect to the underlying substrate such as, e.g., substrate10illustrated inFIG.1, the blade375is also movable with respect to the substrate. In other examples, the substrate is movable with respect to the print system300, and thus movable with respect to the blade375.

In various implementations, the counter-rotating roller340rotates at a speed in the range of 10 RPM to 300 RPM. If the counter-rotating roller340has a rotating speed that is greater or lower than this range, then the resulting quality of the powder deposition may be deteriorated because the uniformity of the deposited powder may be affected by the counter-rotating roller.

In various implementations, a lubricant agent and/or a wetting agent is added to the powder being distributed by the powder feeder350in order to, e.g., increase the flowability of the powder that is deposited in front of the counter-rotating roller340. Adding such lubricant agent and/or a wetting agent may improve the compaction of the powder and minimize or control the tension between the substrate and the compacted powder layer. Specifically, the lubricating agent facilitates obtaining a uniform compaction of the powder that is compacted by the counter-rotating roller340. In implementations, the print system300may include a single counter-rotating roller340, and may avoid having to have an additional compacting roller that rotates in the same direction of the spreading of the deposited powder, i.e., rotates in the opposite direction to the rotation direction of a counter-rotating roller340. Example lubricating agents and wetting agents include water and isopropyl alcohol.

FIG.3Billustrates a detailed portion of the print station illustrated inFIG.3A, in accordance with various example implementations. In various implementations, the portion referred to as “A” inFIG.3Ais discussed in greater detail below. InFIG.3B, the counter-rotating roller340has a radius R, and a distance “d” between a lowest contact point of the counter-rotating roller340to the substrate370, with the lowest contact point being labeled as “B,” and the end point of the blade, labeled as375a. This distance “d” may be in a range of one to two R, for example. 1.5R. In a particular example, the distance “d” may be equal to about R. If the distance “d” is much greater than R, then the powder may undergo rotation in front of the counter-rotating roller340, which results in a poor powder deposition such as, e.g., non-uniform deposition.

In various implementations, a feeder gap390between the lowest portion of the powder feeder350and the surface of the substrate370may be adjustable as desired. Accordingly, the feeder gap390between the substrate and the powder feeder350, or between the previously deposited powder layer and the powder feeder350may be maintained at a desired constant, or substantially constant value to ensure uniform thickness of the deposited powder layer. For example, in order to deposit a single layer of powder, the feeder gap390between the substrate370and the powder feeder350may be adjusted accordingly. The feeder gap390between the surface of the substrate370and the lowest portion of the powder feeder350defines the quality of the deposition. In other implementations, the feeder gap390may be defined between the lowest portion of the blade375and the surface of the substrate370, or the surface of a previously deposited powder layer.

In some implementations, the counter-rotating roller340may also have an adjustable roller gap395between the lowermost surface thereof and the substrate370. In embodiments, the roller gap395being independently adjustable from the feeder gap390. In addition, the roller gap395defines a final thickness of the printed layer, while, as discussed above, the feeder gap390defines the quality of the deposition. In embodiments, the feeder gap390may be greater than the roller gap395. For example, the feeder gap390is greater than the roller gap395and equal to or lower than one-half of the diameter of the counter-rotating roller340. If the feeder gap390is greater than one-half of the diameter of the counter-rotating roller340, then the powder may undergo rotation in front of the counter-rotating roller340, which results in a poor powder deposition such as, e.g., non-uniform deposition.

In some implementations, as illustrated byFIG.3D, the print system300includes the counter-rotating roller340, the powder feeder350with blade375, one or more sensors325,330,335, and a control apparatus360. The one or more sensors325,330,335may comprise point, multi-point or continuous level devices for sensing one or more parameters of a thickness of a powder level, a powder level, or a surface profile or topography of the powder deposited by the powder feeder350, amongst other parameters. As an example, the one or more sensors325,330,335include an ultrasonic thickness sensor, or an optical sensor (such as a laser sensor), though a person of skill in the art will recognize that other forms of thickness or topographic sensors can alternatively be used to measure parameters with respect to the powder deposited by the powder feeder350. In a particular example, sensors325and330are located upstream from the counter-rotating roller340, and additional sensor335is located downstream from the counter-rotating roller340. The one or more sensors325,330,335are connected to the control apparatus360.

For the purposes of explanation,FIG.3Dalso indicates illustrative thickness levels of the powder deposited by the powder feeder350at various stages throughout operation of the print system300in a 3D printing apparatus, in accordance with an example implementation. With reference toFIG.3D, the dashed line315represents a level of powder after it has been deposited by the powder feeder350, prior to encountering the blade375. The dashed line310represents a powder surface level, or thickness310after the powder has been at least partially uniformized by the blade375, prior to encountering the counter-rotating roller340. Powder surface level320is a surface level or thickness of the powder after the powder has been further planarized and uniformized by the counter-rotating roller340, as shown as dashed line320.

In order for an optimum operation of the counter-rotating roller340, and to reduce an accumulation of powder in front of the counter-rotating roller340and achieve uniform compacting of the powder, in one implementation, sensor325may be utilized to acquire a first powder surface height measurement of the powder surface level310, at one or more locations between the blade-shaped end of the powder feeder350and the counter-rotating roller340, for example, just before the counter-rotating roller340. The measurement data acquired from sensor325may be conveyed to the control apparatus360, in which a processing unit (not shown) compares the acquired data of the powder surface level310to a first predetermined powder surface height threshold value stored in a memory of the control apparatus360. The first predetermined powder surface height threshold value is a maximum height at which the powder deposited by the powder feeder350should be allowed to accumulate. Above the first predetermined powder surface height threshold value, powder accumulation in front of the counter-rotating roller340would create conditions resulting in the powder not being able to rotate under the counter-rotating roller340, and increasing the potential of a non-uniform powder layer being created.

Should the processing unit determine that the first powder surface height measurement of the powder surface level310is above the first predetermined powder surface height threshold value (also referred to as the predetermined threshold value), the control apparatus360, via a control unit for the blade375, adjusts the height of the blade375above the substrate370, reducing it such that less powder is allowed to approach the counter-rotating roller340. The amount of adjustment may be determined by the processing unit based on a data table or similar predetermined data, amongst other examples. In some implementations, adjusting the height of the blade375above the substrate370may comprise lowering the blade375such that substantially no further powder is allowed to approach the counter-rotating roller340.

In some implementations, alternatively, or additionally, an amount of powder distributed by the powder feeder350may be adjusted. In one example, sensor330may be utilized to acquire a second powder surface height measurement of the powder surface level315, at one or more locations before the powder encounters the blade375. The measurement data acquired from sensor330may be conveyed to control apparatus360, in which a processing unit (not shown) compares the acquired data to a second predetermined powder surface height threshold value (also referred to as the predetermined threshold value), stored in a memory of the control apparatus360. The second predetermined powder surface height threshold value is a maximum height at which the powder should be allowed to accumulate before the blade375.

Should the processing unit determine that the second powder surface height measurement of the powder surface level315is above the second predetermined powder surface height threshold value, the control apparatus360, via a control unit (not shown) for the powder feeder350, adjusts the amount of powder dispensed, reducing it such that less powder is dispensed before approaching the blade375. In one example, the control unit may communicate with the dispensing controller22(seeFIG.1) to adjust the amount of fluidized material metered. The amount of adjustment may be determined by the processing unit based on a data table or similar predetermined data, amongst other examples. In some implementations, adjusting the powder dispensed by the powder feeder350may include closing an output of the powder feeder350such that substantially no further powder is dispensed.

In other implementations, alternatively, or additionally, additional sensor335may be utilized to acquire a third powder surface height measurement of the powder surface level320, at one or more locations after passing under the counter-rotating roller340, or downstream from the counter-rotating roller340. The measurement data acquired from additional sensor335may be conveyed to control apparatus360, in which a processing unit (not shown) compares the acquired data to a desired powder surface height value, or desired range of values, stored in a memory of the control apparatus360. Should the processing unit determine that the third powder surface height measurement of the powder surface level320deviate from a desired value or range of values of the desired powder surface level, or a predetermined target value, the control apparatus360, via a control unit or an additional control apparatus (not shown) for the counter-rotating roller340, adjusts the height of the lowest contact point of the counter-rotating roller340to the substrate370. The amount of adjustment may be determined by the processing unit based on a data table or similar predetermined data, amongst other examples. In some implementations, in addition or alternatively to adjusting the height of the lowest contact point of the counter-rotating roller340to the substrate370, the amount of powder that passes under the blade375may also be adjusted.

In some implementations, one or more of the sensors325,330,335continually monitor powder thickness, powder level or topographical data in real-time, and adjust the one or more of the heights of the counter-rotating roller340and/or the height of the blade375above the substrate, and/or the amount of powder dispensed by the powder dispenser350. In other implementations, the control apparatus360may be configured to enable one or more feedback operations between one or more of the sensors325,330,335, and control units associated with the powder feeder350, blade375and counter-rotating roller340. In this manner, the feedback, in association with control algorithms can be utilized to provide dynamic adjustment to maintain consistency in the powder uniformization process of a 3D printing operation.

The control apparatus360may comprise software architecture, various portions of which may be used in conjunction with various hardware elements described herein. It will be appreciated that the software architecture may be implemented to facilitate the functionality described herein. The software architecture may be executed on hardware such as a central processing unit that may include, among other things, document storage, processors, memory/storage, and input/output (I/O) components. The architecture may include a processing unit and associated executable instructions. The executable instructions may include implementation of the methods, modules and so forth described herein. The architecture may also include other hardware modules. Drivers may be responsible for controlling or interfacing with the underlying hardware. Drivers may include display drivers, camera drivers, memory/storage drivers, peripheral device drivers, network and/or wireless communication drivers, audio drivers, and so forth depending on the hardware and/or software configuration. Libraries, including data libraries may provide a common infrastructure that may be used by applications and/or other components.

In various implementations, the counter-rotating roller340may be coated by a coating (not shown). For example, the coating may be an anodized coating, a Teflon coating, or a plastic coating. A plastic coating may minimize the friction between the powder and the counter-rotating roller340, and may also minimize powder sticking or adhering on the counter-rotating roller340. For example, during operation of the print system300, the powder that is distributed by the powder feeder350and compacted by the counter-rotating roller340may adhere to the surface of the counter-rotating roller340. The powder adhered on the counter-rotating roller340may impact the quality of subsequent layers of the 3D printed product. A plastic coating on the counter-rotating roller340may decrease such powder sticking. Similarly, an anodized coating to the counter-rotating roller340may provide a decreased powder sticking, and may also reduce friction between the surface of the counter-rotating roller340and the substrate370. As an example, the coating may reduce electrostatic charging of the powder during operation of the print system300. As another example, a thickness of the coating is in a range of 0.1 nm to 500 μm.

FIGS.4A-4Billustrate schematic representations of a print station in accordance with various example implementations. InFIG.4A, the print station400aincludes roller440, powder feeder450comprising blade475, and substrate470. With reference toFIG.3A, roller440may correspond to roller340, and powder feeder450/blade475may correspond to powder feeder350/blade375, and substrate470may correspond to substrate370. InFIG.4A, the print station400afurther includes a vibrating device410a. For example, the vibrating device410ais functionally connected, e.g., integrally connected, to the roller440, and may be configured to vibrate at a rapid frequency in order to make the roller440vibrate at the rapid frequency. For example, the vibrating device410amay vibrate at, e.g., an ultrasonic frequency and thus makes the roller440vibrate at the ultrasonic frequency. As a result of the roller440vibrating at a rapid frequency, e.g., at an ultrasonic frequency, the powder that is in contact with the roller440during the counter-rotation of the roller440may be better distributed, and agglomeration of the powder at the point of contact with the roller440, or in the vicinity of the point of contact with the roller440, may be reduced, significantly reduced, or eliminated.

InFIG.4B, the print station400bincludes roller440, powder feeder450that includes blade475, and substrate470. With reference toFIG.3A, roller440may correspond to roller340, powder feeder450may correspond to powder feeder350, and blade475may correspond to blade375, and substrate470may correspond to substrate370. InFIG.4B, the print station400bfurther includes a vibrating device410b. For example, the vibrating device410bis functionally connected, e.g., integrally connected, to the substrate470, and may be configured to vibrate at a rapid frequency in order to make the substrate470vibrate at the rapid frequency. For example, the vibrating device410bmay vibrate at, e.g., an ultrasonic frequency and thus makes the substrate470vibrate at the ultrasonic frequency. As a result of the substrate470vibrating at a rapid frequency, e.g., at an ultrasonic frequency, the powder that is deposited by the powder feeder450on the substrate470may be better distributed on the substrate470, and agglomeration of the powder at the point of contact with the roller440, or in the vicinity of the point of contact with the roller440, may be reduced, significantly reduced, or eliminated. In various implementations, the print station400a/400bmay include both vibrating devices410aand410b, in which case both the roller440and the substrate470are made to vibrate at the rapid frequency during deposition and distribution of the powder.

In various implementations, the powder feeder450may enclose therein one or more devices or elements460designed to control or influence the environment where the powder is stored before being distributed. For example, the devices or elements460may be any combination of a dehumidifier, one or more heating elements, and an inert gas provider configured to provide an inert gas inside the powder feeder450. Any one of these devices or elements460, whether alone or in combination, may be enclosed in the powder feeder450in order to ensure that the powder remains sufficiently dry and un-agglomerated, and thus to ensure a sufficient quality of the resulting printed layer.

In various implementations, the counter-rotating roller440may include an electric charging mechanism420that delivers an electric charge to the surface of the counter-rotating roller440to remove any powder that may adhere to the surface of the counter-rotating roller440via static charging. Alternatively, the electric charge delivered to the surface of the counter-rotating roller440by the electric charging mechanism420may prevent the powder from adhering to the surface of the counter-rotating roller440via static charging.

FIG.5illustrates a method of operation of a print station in a 3D printing apparatus, in accordance with various example implementations. In the process500ofFIG.5, at S510, a print system is arranged over a substrate, the substrate having a longitudinal axis. With reference toFIG.2, the printing system210is arranged over the substrate270or the support220. The process500continues to S520, where a powder is distributed on the substrate through a powder feeding device of the print system. For example, the powder is distributed on the powder bed of a print station that is part of a 3D printing apparatus. With reference toFIGS.3A and3B, the powder is distributed from the powder feeder350. In implementations, a lubricating agent and/or a wetting agent may be added to the powder that is distributed at S520, the lubricating agent and/or wetting agent being configured to increase the flowability of the powder and the compaction uniformity. By controlling the surface tension of the powder, the lubricating agent and/or wetting agent may also prevent or reduce powder sticking to the roller.

In various implementations, as the powder is distributed at S520, the process500continues to S530by contemporaneously or simultaneously flattening the distributed powder via, e.g., a blade integrated into the powder feeding device. For example, the flattening at S530may maintain a constant thickness of the powder distributed on the substrate. With reference toFIGS.3A and3B, as the powder is distributed via the powder feeder350, the powder is contemporaneously flattened by the blade375. The process500continues to S540where the powder is transported to a uniformization device along a moving direction of the powder, the moving direction being parallel to the longitudinal axis of the substrate. For example, the uniformization device may be a roller located at a desired distance from the blade375, the roller being configured to apply a pressure on the powder. The process500continues to S550where the powder is uniformized by the uniformization device. With reference toFIGS.3A and3B, the powder is uniformized by the counter-rotating roller340which rotates and applies pressure on the powder. In implementations, the counter-rotating roller340rotates in a direction opposing the moving direction of the powder or the direction of the spreading of the deposited powder on the substrate. The process500continues to S560, where the powder is transferred to the next station in the 3D printing process such as, e.g., binder printing in a printing device, fixing in a fixing device, or transferred to a transfer device. With reference toFIG.1, the powder may be transferred to the binder printing device40, the fixing device50, or the transfer device76.

FIG.6illustrates a schematic representation of print system600, in accordance with various example implementations described with respect toFIGS.1-5. With reference toFIGS.1-5, print system600includes a plurality of powder feeders650,655. The powder feeders650,655, may dispense the same powder as each other, or different powders, allowing for multi-material deposition. Further,FIG.6illustrates each powder feeder of the powder feeders650,655is attached to a support or mounting apparatus610. In some embodiments, each powder feeder of the powder feeders650,655, is located along a longitudinal axis of the print system600, a longitudinal axis of the support or mounting apparatus610, and/or a longitudinal axis of the substrate670. The print system600may include one or more powder uniformization devices640, which may be attached to the same support or mounting apparatus610to move together with the powder feeders650and655. Alternatively, the powder uniformization device640may be attached to a support or mounting apparatus different from support or mounting apparatus610to move independently with the powder feeders650,655. In some embodiments, support or mounting apparatus610is configured to control movement of the powder feeders650,655and powder uniformization device640, via a controller (not shown), either from right to left, or from left to right along the longitudinal axis formed by the support or mounting apparatus610, in order to deposit powder on the substrate670. Alternatively, or additionally, the support or mounting apparatus610is configured to control the movement of the powder feeders650,655and powder uniformization device640in a direction, substantially perpendicular to the longitudinal axis form by the support or mounting apparatus610in order to deposit powder on the substrate670. In some embodiments, one of the support or mounting apparatus610and the substrate670is configured to move in first and second directions, wherein the first direction may be opposed to the second direction, substantially parallel to the longitudinal direction, while the other of the support or mounting apparatus610and the substrate670remains stationary. In some implementations, the support or mounting apparatus610, the powder feeders650,655, and the powder uniformization device640are movable together. Alternatively, the support or mounting apparatus610is static while the powder feeders650,655and the powder uniformization device640are movable. In some embodiments, the print system600may be movable with respect to the substrate670along the longitudinal axis formed by the substrate670, and the substrate670may remain stationary with respect to the longitudinal axis. In other embodiments, the substrate670may be movable with respect to the print system600along the longitudinal axis formed by the substrate670, and the print system600may remain stationary with respect to the longitudinal axis. Alternatively, both the print system600and the substrate670may be movable with respect to each other along the longitudinal axis.

In some embodiments, the print system600may further comprise a carrier device, as illustrated inFIG.1(which may include a conveyor) to transport the substrate670from a first location to a second location.

In some embodiments, the powder feeders650,655, may correspond to powder feeders350,450, and may include all of their features as described with respect toFIGS.3A,3B,4A, and4B, including each powder feeder of the powder feeders650,655, having a blade-shaped end. In some embodiments, each blade-shaped end has a lower surface substantially parallel to the substrate670. In further embodiments, a distance between a lowest contact point of the powder uniformization device640to the substrate670and an end point of each blade of each powder feeder of the powder feeders650,655, is equal to about one radius of the roller of the powder uniformization device640. As a further example, the powder feeders650,655, may each enclose one or more devices or elements designed to control or influence the environment where the powder is stored before being distributed by any one of the powder feeders650,655. As a further example, the devices or elements may be any combination of a dehumidifier, one or more heating elements, and an inert gas provider configured to provide an inert gas inside the powder feeders650,655. Any one of these devices or elements may be enclosed in any one of the powder feeders650,655, in order to ensure that the powder remains sufficiently dry and un-agglomerated, and thus to ensure a sufficient quality of the resulting printed layer.

As shown inFIG.6, the print system600includes a uniformization device, i.e., powder uniformization device640, located adjacent at least one powder feeder of the plurality of powder feeders650,655. For example between the plurality of powder feeders650,655. The powder uniformization device640uniformizes powder deposited by the powder feeders650,655onto the substrate670. In some embodiments, the powder uniformization device640may include a roller which corresponds to rollers340,440, and may include all of their features as described with respect toFIGS.3A,3B,4A, and4B.

In some embodiments, the powder feeders650,655may contain different powder materials, and the powder uniformization device640may comprise two or more powder uniformization devices (not shown). The implementation of two or more powder uniformization devices ensures that there is no powder cross contamination. For example, in the case where powder feeder650dispenses a first powder material, and powder feeder655dispenses a second powder material, powder uniformization device640may comprise two independent powder uniformization devices640aand640b(not shown). With powder uniformization device640aoperated to uniformize powder deposited by the powder feeder650, and powder uniformization device640boperated to uniformize powder deposited by the powder feeder655.

In further embodiments, the print system600may include a vibrating device (not shown) connected to a roller of the powder uniformization device640, similar to vibrating device410afunctionally connected to the roller440. Further, the print system600may include a vibrating device (not shown) connected to the substrate670, similar to the vibrating device410bfunctionally connected to the substrate470. In embodiments, these vibrating devices of the print system600are configured to vibrate at a rapid frequency in order to make the roller of the powder uniformization device640or the substrate670vibrate at the rapid frequency, similar to vibrating devices410a,410breferenced inFIGS.4A and4B. For example, a vibrating device of the print system600may vibrate at, e.g., an ultrasonic frequency, thereby making the roller of the powder uniformization device640vibrate at the ultrasonic frequency. As a result of the roller of the powder uniformization device640or substrate670vibrating at a rapid frequency, e.g., at an ultrasonic frequency, the powder that is in contact with the roller of the powder uniformization device640may be better distributed. Further, an agglomeration of the powder at the point of contact with the roller of the powder uniformization device640, or in the vicinity of the point of contact with the roller of the powder uniformization device640, may be reduced, significantly reduced, or eliminated.

Generally, powder deposition by a powder feeder occurs in only one direction. For example, when printing a structure over a stationary build platform, a powder feeder may travel from right to left depositing a first layer of powder. In this example, the powder feeder then travels back from left to right without depositing powder to an original location of the powder feeder. The powder feeder then travels from right to left depositing a second layer of powder. Such a printing system is relatively inefficient since an amount of time for the powder feeder to travel back from left to right is wasted.

As shown inFIG.6, the print system600addresses the issue of wasteful movement by providing powder feeders650,655, which are movable along various directions660,665. In this way, the powder feeders650,655allow for the deposition of a powder onto the substrate670along each of these directions660,665, thereby eliminating the wasteful steps of powder feeders traveling without depositing powder. For example, the print system600includes two powder feeders650,655, which are configured to distribute or apply powder one layer at a time over a substrate670in various directions. Accordingly, the powder feeders650,655improve printing efficiency of the print system600by being able to deposit powder in various directions without any wasteful movement.

In some embodiments, the powder feeders650,655may be discrete devices, disposed next to each other and configured to move together as a unit. As an example, the powder feeders650,655may be integrated into a single device allowing them to move in a synchronized fashion as a pair. Alternatively, the powder feeders650,655may be integrated as single devices allowing them to move independently from one another. As a specific example, powder feeder650is activated to distribute powder and performs a pass from right to left over substrate670, while powder feeder655is prevented from distributing powder. Similarly, as powder feeder655performs a pass from left to right over the substrate670, it is activated to distribute powder, and powder feeder650is prevented from distributing powder. In further examples, powder feeders650,655may be stationary, and the substrate670may move beneath them. In this example, the direction of travel of the substrate670determines which powder feeder of powder feeders650,655is activated to distribute powder and which is prevented from doing so. In this way, activation of the powder feeders650,655are synchronized with a direction of travel of the powder feeders650,655and/or the substrate670over which they travel.

In some embodiments, the directions660,665are opposing directions, with direction660opposing direction665, and vice versa. As shown inFIG.6, powder uniformization device640is rotatable in directions645,645a, along the substrate670. Specifically, the roller of the powder uniformization device640is a counter-rotating roller, such as described with respect to rollers240,340, and operates to compact the powder that has been dispensed by the powder feeders650,655. In this way, the powder uniformization device640is able to uniformize powder deposited by the powder feeders650,655, regardless of a direction of the directions660,665the powder feeders650,655move along.

As an example, in order to accommodate both powder feeders650,655, the powder uniformization device640is configured to rotate in whichever direction of the directions645,645athat is appropriate based on whether powder feeder650or powder feeder655is activated and dispensing powder. As a more specific example, the powder uniformization device640rotates in a clockwise direction645when powder feeder650is activated, i.e., as it moves from right to left, in direction660. Further, the powder uniformization device640rotates in counter-clockwise direction645awhen powder feeder655is activated, i.e., as it moves from left to right, in direction665. In this way, to accommodate a plurality of materials deposited by the powder feeders650,655, the powder uniformization device640needs to rotate in one direction for a first powder from powder feeder of the powder feeders650,655, and an opposite direction for a second powder from powder feeder of the powder feeders650,655. Alternatively, the powder uniformization device640may comprise a plurality of powder uniformization devices; with each of the plurality of powder uniformization devices activated to rotate in a direction synchronized with the movement and activation of one of the powder feeders650,655. Such a configuration can help prevent powder cross contamination when a plurality of materials is deposited.

In some embodiments, synchronization of the roller of the powder uniformization device640is based on which direction a powder feeder of the powder feeders650,655is moving relative to the substrate670, or which direction the substrate670is moving relative to the powder feeders650,655. In further embodiments, a powder uniformization device controller may control a rotation direction of the roller of the powder uniformization device640, based on data related to a direction of the directions660,665of the powder feeders650,655, data related to activation of the powder feeders650,655, and/or the direction of the substrate670.

In some embodiments, each direction of the directions660,665is relative to the substrate670in response to the substrate670being static. In this embodiment, the print system600is movable along a longitudinal axis, while the substrate670remains static. In this way, each powder feeder of the powder feeders650,655is synchronized depending on which direction the powder feeders650,655are moving relative to the substrate670. Alternatively, the substrate670is movable along a longitudinal axis relative to the powder feeders650,655, thereby dictating which powder feeder of the powder feeders650,655needs activation. In this way, each powder feeder of the powder feeders650,655is synchronized depending on which direction the substrate670is moving relative to the powder feeders650,655. As a specific example, powder feeders650,655may be stationary, and the substrate670may move beneath them. In this example, the direction of travel of the substrate670determines which powder feeder of the powder feeders650,655is activated to distribute powder and which is prevented from doing so. In further embodiments, the substrate670is movable with respect to the print system600along a longitudinal axis. Accordingly, print system600allows for powder from the powder feeders650,655to be deposited on the substrate670, regardless of which direction the substrate670is moving.

FIG.7illustrates a schematic representation of a print system700in accordance with various example implementations described with respect toFIGS.1-6. With reference toFIGS.1-6, print system700includes a plurality of powder feeders750,755, each having a blade-shaped end. Further,FIG.7illustrates each powder feeder of the powder feeders750,755is attached to a support or mounting apparatus710.

The print system700includes powder uniformization devices720,760, located adjacent to at least one powder feeder of the plurality of powder feeders750,755. The powder uniformization devices720,760uniformize powder deposited by the powder feeders750,755onto the substrate670. In some embodiments, the powder uniformization devices720,760may include a roller which corresponds to rollers340,440,640and may include all of their features as described with respect toFIGS.3A,3B,4A,4B and6. For example, powder uniformization devices720,760may rely on counter-rotating rollers to promote uniformity of the deposited powder. In some implementations, the powder uniformization devices720,760may be attached to the support or mounting apparatus710in a manner that allows them to be moved in a direction substantially perpendicular to the substrate670. For a uniformization device of the uniformization devices720,760which is not activated to rotate, a roller gap may be increased, and for a uniformization device of the uniformization devices720,760which is activated to rotate, the roller gap may be adjusted to define a thickness of the printed layer.

The powder feeders750,755may contain different powder materials, and utilization of two powder uniformization devices720,760ensures that there is no powder cross contamination. As a specific example, the powder uniformization device720rotates in a clockwise direction725when powder feeder750is activated, i.e., as it moves from right to left, in the direction660. The powder uniformization device760rotates in a counter-clockwise direction765when powder feeder755is activated, i.e., as it moves from left to right, in direction665. In this way, each of the plurality of powder uniformization devices720,760is configured to be activated to rotate in a direction synchronized with the movement and activation of one of the powder feeders750,755. Such a configuration can help prevent powder cross contamination when a plurality of materials is deposited.

In some embodiments, synchronization of the powder uniformization devices720,760is based on which direction a powder feeder of the powder feeders750,755is moving relative to the substrate670, or which direction the substrate670is moving relative to the powder feeders750,755. In some embodiments, each direction of the directions660,665is relative to the substrate670in response to the substrate670being static. In this embodiment, the print system700is movable along a longitudinal axis, while the substrate670remains static. In this way, each powder feeder of the powder feeders750,755is synchronized depending on which direction the powder feeders750,755are moving relative to the substrate670. Alternatively, the substrate670is movable along a longitudinal axis relative to the powder feeders750,755, thereby dictating which powder feeder of the powder feeders750,755needs activation. In this way, each powder feeder of the powder feeders750,755is synchronized depending on which direction the substrate670is moving relative to the powder feeders750,755.

In some implementations, the print system700further comprises additional compaction devices730,740, that are configured to rotate in the same direction of the spreading of the deposited powder (directions735and745) i.e., rotate in the opposite direction to the directions725,765of the counter-rotating rollers of the uniformization devices720,760. In other implementations, the print system700may be configured such that powder uniformization devices720,760serve as both uniformization devices and additional compaction devices. For example, when powder feeder750is activated, i.e., as it moves from right to left, in direction660, the powder uniformization device720rotates in a clockwise direction725and the powder uniformization device760is operated as an additional compaction device rotating in a counterclockwise direction765, i.e., in the opposite direction to the direction of725. Similarly, when powder feeder755is activated, i.e., as it moves from left to right, in direction665, the powder uniformization device760rotates in the counter-clockwise direction765and the powder uniformization device720is operated as an additional compaction device rotating in a clockwise direction725, i.e., in the opposite direction to the direction of765.

FIG.8illustrates a schematic representation of print system800in accordance with various example implementations described with respect toFIGS.1-7. Print system800includes a plurality of powder feeders850,850a,855,855a. The powder feeders850,850a,855,855amay dispense the same powder as each other, or different powders, allowing for multi-material deposition. In some configurations, powder feeders850,855amay dispense a first powder material, and powder feeders850a,855may dispense a second powder material. The print system800may include one or more of the features described in relation toFIGS.6and7, with the powder feeders650,655,750,755, and powder uniformization devices640,720,760. For example, in embodiments, the powder feeders850,850a,855,855amay correspond to powder feeders350,450, and may include all of their features as described with respect toFIGS.3A,3B,4A, and4B, including each powder feeder of the powder feeders850,850a,855,855ahaving a blade-shaped end.

In some embodiments, the print system800may further comprise a carrier device, such as the carrier device12illustrated inFIG.1(which may include a conveyor) to transport the substrate670from a first location to a second location.

As shown inFIG.8, the print system800includes a uniformization device, i.e., powder uniformization device840, located adjacent to powder feeders850,850a,855,855a, for example between the plurality of powder feeders850,850a,855,855a. The powder uniformization device840uniformizes powder deposited by the powder feeders850,850a,855,855aonto the substrate670, and rotates in clockwise direction845and/or counter-clockwise direction845a. In some embodiments, the powder uniformization device840may include a roller which corresponds to rollers340,440, and may include all of their features as described with respect toFIGS.3A,3B,4A, and4B. In some embodiments, two or more of the powder feeders850,850a,855,855amay contain different powder materials, and/or powder uniformization device840may comprise two or more powder uniformization devices (not shown). The implementation of two or more powder uniformization devices ensures that there is no powder cross contamination. For example, in a case where powder feeders850,855adispense a first powder material, and powder feeders850aand855dispense a second powder material, powder uniformization device840may comprise two independent powder uniformization devices840aand840b(not shown). With powder uniformization840aoperated to uniformize powder deposited by the powder feeders850,855a, and powder uniformization840boperated to uniformize powder deposited by the powder feeders850a,855.

In embodiments, the powder feeders850,850a,855,855amay be discrete devices, disposed next to each other and configured to move together as a unit. As an example, the powder feeders850,850amay be integrated into a single device allowing them to move in a synchronized fashion as a pair. Alternatively, the powder feeders850,850a,855,855amay be integrated as single devices allowing them to move independently from one another. As a specific example, the powder feeders850,850a,855,855aare synchronized with a direction of travel of the powder feeders850,850a,855,855aand/or the substrate670over which they travel. In further examples, powder feeders850,850a,855and855amay be stationary, and the substrate670may move beneath them. In this example, the direction of travel of the substrate670determines which powder feeder of powder feeders850,850a,855and855ais activated to distribute powder, and which powder feeder is prevented from doing so.

To accommodate a plurality of materials deposited by the powder feeders850,850a,855,855a, in one embodiment the powder uniformization device840is configured to rotate in one direction when powder is distributed from two of the powder feeders from the powder feeders850,850a,855,855a, (for example powder feeders850,855a), and an opposite direction when powder is distributed from the other two powder feeders850,850a,855,855a, (for example powder feeders850a,855). Alternatively, the powder uniformization device840may comprise a plurality of powder uniformization devices, each of the plurality of powder uniformization devices activated to rotate in a direction synchronized with the movement and activation of one or more of the powder feeders850,850a,855,855a. Such a configuration can help prevent powder cross contamination when a plurality of materials is deposited. In yet another embodiment, the powder uniformization devices may be attached to the support or mounting apparatus810in a manner that allows them to be moved in a direction substantially perpendicular to the substrate670. In a further embodiment, the powder uniformization devices may be attached to the support or mounting apparatus810in a manner that allows them to be moved in a direction at an angle less than 90 degree to the substrate670. For those uniformization devices which are not activated to rotate, the roller gap may be increased, and for those uniformization devices which are activated to rotate, the roller gap may be adjusted to define the final thickness of the printed layer.

The print system800includes a plurality of binder jetting devices880,880a. In one embodiment, the binder jetting devices880,880aare integrated with the powder feeders850,850a,855,855ato provide a unit that can move as a single device arrangement in a single pass. For example, the binder jetting device880may be integrated with powder feeders850,850ato provide a unit that can move as a single device arrangement in a single pass. In a further embodiment, the print system800allows for powder to be deposited by powder feeders850,850a,855,855a, along with an injection of a binder, e.g., a UV-curable resin, by the binder jetting devices880,880a. In further embodiments, the print system800allows for the application of a fixing device, e.g., a UV radiation device, to cure the UV-curable resin. As a result, the speed of the layer formation and binder curing is substantially increased because there is no need for an additional post-deposition curing process. In some embodiments, the powder feeders850,850a,855,855aand/or the powder uniformization device840are synchronized with the binder jetting devices880,880a. Similarly, any other devices, such as a fixing device, are similarly synchronized to be activated based on the direction of the powder feeders850,850a,855,855a, which are activated, and their location with respect to the substrate670.

FIG.9illustrates a method of operation of a print system in a 3D printing apparatus, in accordance with various example implementations. In the process900ofFIG.9, at S910, a print system of the print systems600,700,800is arranged over a substrate670, as shown inFIGS.6-8. At S920, a first powder is distributed on the substrate670in a first direction, e.g., direction660, using a first powder feeder of the powder feeders650,655of the print system600, the powder feeders750,755of the print system700, or powder feeders850,850a,855,855aof the print system800. At S930, a uniformization device, i.e., powder uniformization device640,720,760or840, located at a first distance from the first powder feeder, uniformizes the first powder. At S940, a second powder is distributed on the substrate670in a second direction, e.g., direction665opposing the first direction660, using a second powder feeder of the powder feeders650,655of the printing system600, powder feeders750,755of the print system700, or powder feeders850,850a,855,855aof the print system800. At S950, the uniformization device, e.g., powder uniformization device640,720,760or840located at a second distance from the second powder feeder, uniformizes the second powder. In some embodiments the first powder dispensed may be the same or a different material from the second powder dispensed.

In the following, further features, characteristics, and advantages of the instant application will be described via the following items:

Item 1: A three-dimensional (“3D”) printing system for printing on a substrate, the printing system comprising: a powder distribution device dispensing powder on the substrate and including a blade-shaped end, the blade-shaped end disposed at a height above the substrate; a powder uniformization device located at a distance from the powder distribution device along a direction substantially parallel to a longitudinal axis of the substrate; one or more sensors disposed upstream from the powder uniformization device and configured to determine one or more parameters of a thickness of the dispensed powder at one or more locations; and a control apparatus configured to determine whether the one or more parameters of the thickness is above a predetermined threshold value, and if the one or more parameters is determined to be above the predetermined threshold value, to adjust the powder distribution device.

Item 2: The printing system of item 1, wherein the one or more sensors is disposed between the blade-shaped end and the powder uniformization device.

Item 3: The printing system of items 1 and 2, wherein the control apparatus is configured to adjust the height at which the blade-shaped end is disposed above the substrate.

Item 4: The printing system of items 1-3, wherein the height at which the blade-shaped end is disposed above the substrate is adjusted such that substantially no further powder from the powder distribution device approaches the powder uniformization device.

Item 5: The printing system of any one of items 1-4, wherein the control apparatus is configured to adjust an amount of the powder dispensed by the powder distribution device.

Item 6: The printing system of any one of items 1-5, wherein the powder distribution device is configured to dispense substantially no powder.

Item 7: The printing system of any one of items 1-6, wherein the further comprising an additional sensor to determine one or more additional parameters of the thickness at one or more locations downstream from the powder uniformization device, wherein the control apparatus is further configured to: determine whether the one or more additional parameters of the thickness at the one or more locations downstream from the powder uniformization device is above a predetermined target value, and if the one or more additional parameters is determined to deviate from the predetermined target value, to adjust the powder distribution device.

Item 8: The printing system of any one of items 1-7, wherein the adjusting the powder distribution device comprises adjusting the height at which the blade-shaped end is disposed above the substrate.

Item 9: The printing system of any one of items 1-8, wherein the adjusting the powder distribution device comprises adjusting an amount of the powder dispensed by the powder distribution device.

Item 10: The printing system of any one of items 1-9, further comprising an additional control apparatus configured to adjust a height of a lowest contact point of the powder uniformization device to the substrate if the thickness at the one or more locations downstream from the powder uniformization device deviates from the predetermined target value.

Item 11: The printing system of any one of items 1-10, wherein the one or more sensors and the control apparatus are configured to operate such that they provide dynamic adjustment of a powder uniformization process of the 3D printing system, to maintain a consistency of the powder uniformization process.

Item 12: A method for printing comprising: dispensing a powder on a substrate using a powder distribution device having a blade-shaped end, the blade-shaped end disposed at a height above the substrate; determining one or more parameters of a thickness of the dispensed powder at one or more locations using one or more sensors disposed upstream from a powder uniformization device; determining whether the one or more parameters is above a predetermined threshold value; and adjusting the powder distribution device in response to the one or more parameters being determined to be above the predetermined threshold value.

Item 13: The method of item 12, wherein the adjusting the powder distribution device comprises adjusting the height at which the blade-shaped end is disposed above the substrate.

Item 14: The method of items 12 and 13, wherein the adjusting the height at which the blade-shaped end is disposed above the substrate is adjusted such that substantially no further powder from the powder distribution device approaches the powder uniformization device.

Item 15: The method of any one of items 12-14, wherein the adjusting the powder distribution device comprises adjusting an amount of the powder dispensed by the powder distribution device.

Item 16: The method of any one of items 12-15, wherein the adjusting the amount of the powder dispensed by the powder distribution device comprises adjusting the powder distribution device so that substantially no powder is dispensed.

Item 17: The method of any one of items 12-16, further comprising: determining one or more additional parameters of the thickness at one or more locations downstream from the powder uniformization device using an additional sensor; and adjusting the powder distribution device in response to the one or more additional parameters being determined to deviate from a predetermined target value.

Item 18: The method of any one of items 12-17, wherein the adjusting the powder distribution device comprises adjusting the height at which the blade-shaped end is disposed above the substrate.

Item 19: The method of any one of items 12-18, wherein the adjusting the powder distribution device comprises adjusting the powder distribution device so that substantially no powder is dispensed.

Item 20: The method of any one of items 12-19, wherein the adjustment of the powder distribution device is dynamic, to maintain a consistency of a powder uniformization process provided by the powder uniformization device.

While various implementations have been described, the description is intended to be exemplary, rather than limiting, and it is understood that many more implementations and implementations are possible that are within the scope of the implementations. Although many possible combinations of features are shown in the accompanying figures and discussed in this detailed description, many other combinations of the disclosed features are possible. Any feature of any implementation may be used in combination with or substituted for any other feature or element in any other implementation unless specifically restricted. Therefore, it will be understood that any of the features shown and/or discussed in the present disclosure may be implemented together in any suitable combination. Accordingly, the implementations are not to be restricted except in light of the attached claims and their equivalents. Also, various modifications and changes may be made within the scope of the attached claims.

While the foregoing has described what are considered to be the best mode and/or other examples, it is understood that various modifications may be made therein and that the subject matter disclosed herein may be implemented in various forms and examples, and that the teachings may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim any and all applications, modifications and variations that fall within the true scope of the present teachings.

Unless otherwise stated, all measurements, values, ratings, positions, magnitudes, sizes, and other specifications that are set forth in this specification, including in the claims that follow, are approximate, not exact. They are intended to have a reasonable range that is consistent with the functions to which they relate and with what is customary in the art to which they pertain.

The scope of protection is limited solely by the claims that now follow. That scope is intended and should be interpreted to be as broad as is consistent with the ordinary meaning of the language that is used in the claims when interpreted in light of this specification and the prosecution history that follows and to encompass all structural and functional equivalents. Notwithstanding, none of the claims are intended to embrace subject matter that fails to satisfy the requirement of Sections 101, 102, or 103 of the Patent Act, nor should they be interpreted in such a way. Any unintended embracement of such subject matter is hereby disclaimed.

Except as stated immediately above, nothing that has been stated or illustrated is intended or should be interpreted to cause a dedication of any component, step, feature, object, benefit, advantage, or equivalent to the public, regardless of whether it is or is not recited in the claims.

It will be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein.

Relational terms such as first and second and the like may be used solely to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “a” or “an” does not, without further constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various examples for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claims require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed example. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.