Printing Head Assembly Adjustment Method

Abstract

To provide a print assembly capable of preventing a leak in a manifold of the print assembly.SOLUTION: Provided is a method of adjusting a printing head assembly including a plurality of print heads. A manifold assembly includes an inlet manifold and an outlet manifold. The inlet manifold has a first pressure. The outlet manifold has a second pressure. A control unit closes all of a plurality of inlet valves and a plurality of outlet valves to prevent a binder material from flowing from the inlet manifold to a corresponding print head and from the corresponding print head to the outlet manifold. The control unit opens a bypass valve to allow the binder material to flow from the inlet manifold to the outlet manifold, and changes at least one of the first pressure and the second pressure to establish a pressure difference between the inlet manifold and the outlet manifold.SELECTED DRAWING: Figure 13

Description

[Technical Field]

[0001] FIELD OF THE INVENTION This disclosure relates generally to print assemblies, and more particularly to print assemblies for manufacturing equipment and methods for using the same. [Background technology]

[0002] Print assembly can be used to "build" an object, such as a three-dimensional object or part, layer by layer from a build material. Early iterations of print assembly were used to prototype three-dimensional parts. However, as print assembly technology has improved, interest in utilizing print assembly for large-scale commercial production of parts has increased. Issues with scaling print assembly to commercial production include, but are not limited to, preventing pressure fluctuations due to spatial separation between the print assembly's nozzles and ink reservoirs, preventing leaks between receptacles, and preventing defects during print assembly calibration and unclog operations.

[0003] Print assemblies utilized in various contexts, including, for example, manufacturing applications, jet printing applications, and other printing types, typically involve problems parallel to those described above. For example, manufacturing equipment typically includes a print assembly, also referred to as a printhead device, which deposits material through an array of jet nozzles during the manufacturing process. These printhead devices typically utilize a manifold with dual receptacles for inlet and outlet flow control to the individual printheads. However, these manifolds require precise control of pressure while driving fluid flow through the manifold and the individual printheads and recirculating material therethrough. Furthermore, these printhead devices do not allow for control of material flow between the manifold and the individual printheads. Without this independent control, individual printheads cannot be isolated during adjustment and clearing operations, wasting material and time. Additionally, insufficient pressure may be directed at a clogged printhead without the ability to selectively control which printhead to open or close to control material flow therethrough. Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, there is a need for an alternative print assembly and its components that prevents leaks in the print assembly manifold and independently controls the flow of material to and from the printhead. [Means for solving the problem]

[0005] A first embodiment A1 is a print assembly including: a manifold assembly including an inlet manifold including an inlet reservoir and a plurality of inlet ports, an outlet manifold including an outlet reservoir and a plurality of outlet ports, a plurality of inlet valves in the inlet manifold, and a plurality of outlet valves in the outlet manifold; a housing; and a plurality of printheads disposed within the housing, each of the plurality of printheads in fluid communication with the inlet reservoir through a corresponding one of the plurality of inlet ports and with the outlet reservoir through a corresponding one of the plurality of outlet ports, each of the plurality of inlet valves and the plurality of outlet valves independently operable to allow or prevent flow of binder material from the inlet reservoir to the corresponding one of the plurality of printheads and from the corresponding one of the plurality of printheads to the outlet reservoir, respectively.

[0006] A second aspect A2 is the print assembly of aspect A1, wherein the manifold assembly is disposed within the housing of the printing head.

[0007] A third aspect A3 is the print assembly of either aspect A1 or A2, further including a plurality of inlet tubes, each of the plurality of inlet tubes coupling a corresponding one of the plurality of print heads to a corresponding one of the plurality of inlet ports, and a plurality of outlet tubes, each of the plurality of outlet tubes coupling a corresponding one of the plurality of print heads to a corresponding one of the plurality of outlet ports.

[0008] A fourth embodiment, A4, is the print assembly of any of embodiments A1-A3, further including a plurality of inlet fittings, each of which is coupled to a corresponding one of the plurality of inlet ports and which are arranged in alternating angular orientations; and a plurality of outlet fittings, each of which is coupled to a corresponding one of the plurality of outlet ports and which are arranged in alternating angular orientations.

[0009] A fifth embodiment A5 is the print assembly of any of embodiments A1 to A4, wherein the inlet manifold is separable from the outlet manifold.

[0010] A sixth aspect A6 is the print assembly of any of aspects A1-A5, further comprising a plurality of actuators, each of which is directly coupled to a corresponding one of the plurality of inlet valves or a corresponding one of the plurality of outlet valves to move the corresponding valve between an open position and a closed position.

[0011] A seventh embodiment, A7, is the print assembly of any of embodiments A1-A6, including a first bypass port through the inlet manifold, a second bypass port through the outlet manifold, and a bypass line fluidly connecting the first bypass port to the second bypass port to allow binder material to flow from the inlet reservoir to the outlet reservoir without passing through any one of the plurality of printheads.

[0012] An eighth embodiment A8 is the print assembly of embodiment A7, wherein at least one of the first bypass port and the second bypass port is coupled to a corresponding bypass valve operable between an open position that allows binder material to flow from the inlet reservoir into the outlet reservoir and a closed position that prevents binder material from flowing from the inlet reservoir into the outlet reservoir.

[0013] A ninth aspect A9 is a print assembly of any of aspects A1 to A8, wherein each of the plurality of inlet valves and the plurality of outlet valves includes a receptacle and a plunger received in the receptacle, the plunger being movable between a raised position when the corresponding valve is in the open position and a lowered position when the corresponding valve is in the closed position.

[0014] A tenth embodiment, A10, is the print assembly of embodiment A9, wherein the plunger includes a seal at the end of the plunger opposite the receptacle to provide an airtight seal between the plunger and an associated port when the plunger is in the lowered position.

[0015] An eleventh embodiment A11 is the print assembly of embodiment A9, wherein each of the plurality of inlet valves and the plurality of outlet valves includes a proximity sensor within the receptacle to detect whether the plunger is in the open position or the closed position.

[0016] A twelfth embodiment A12 is the print assembly of any of embodiments A1-A12, wherein each of the plurality of inlet valves and the plurality of outlet valves includes a pneumatic actuator for switching between the open position and the closed position.

[0017] A thirteenth embodiment A13 is the print assembly of any of embodiments A1-A13, wherein each of the valves includes an electric actuator for switching between the open position and the closed position.

[0018] A fourteenth embodiment A14 is the print assembly of any of embodiments A1-A13, further comprising a fluid level float in at least one of the inlet manifold and the outlet manifold for sensing a level of material.

[0019] A fifteenth embodiment A15 is the print assembly of embodiment A14, wherein the fluid level float is configured to detect a level of binder material in the manifold assembly, and the fluid level float is configured to send a signal to a control system to perform an alarm function if the level of the binder material exceeds a predetermined threshold.

[0020] A sixteenth embodiment A16 is the print assembly of embodiment A14, wherein the fluid level float is an analog float configured to continuously monitor the level of binder material.

[0021] A seventeenth embodiment A17 is the print assembly of embodiment A14, wherein the inlet manifold and the outlet manifold each include a first fluid level float and a second fluid level float, the first fluid level float configured to detect when the binder material exceeds a predetermined low threshold, and the second fluid level float configured to detect when the binder material exceeds a predetermined high threshold.

[0022] An eighteenth embodiment, A18, is the print assembly of any of embodiments A1-A17, further including a fluid level monitoring device that allows visual monitoring of the level of binder material in at least one of the inlet manifold and the outlet manifold.

[0023] A nineteenth embodiment A19 is the print assembly of any of embodiments A1-A18, further including a retainer bracket configured to secure the inlet manifold and the outlet manifold relative to the printing head.

[0024] A twentieth embodiment, A20, is the print assembly of any of embodiments A1-A19, wherein at least one of the plurality of inlet valves and the plurality of outlet valves includes a camshaft including at least one lobe, and rotation of the camshaft moves the lobe to open or close a corresponding one of the plurality of inlet ports or the plurality of outlet ports.

[0025] A twenty-first embodiment A21 is the print assembly of embodiment A20, wherein the camshaft is coupled to a rotary actuator.

[0026] A twenty-second embodiment A22 is the print assembly of embodiment A21, wherein the camshaft has multiple lobes associated with corresponding ones of the multiple inlet ports or the multiple outlet ports such that a corresponding one of the multiple inlet ports or the multiple outlet ports can be opened and closed multiple times during a single complete rotation of the camshaft.

[0027] A twenty-third embodiment, A23, is a print assembly of any of embodiments A1 to A22, further including a vacuum disposed within at least one of the inlet manifold and the outlet manifold, the at least one vacuum establishing a pressure differential between the inlet manifold and the outlet manifold.

[0028] A twenty-fourth embodiment A24 is the print assembly of embodiment A23, wherein the pressure differential during normal operation ranges from -1.0 psi to 0.0 psi, and the pressure differential during purge operation ranges from 0.7 psi to 2 psi.

[0029] A twenty-fifth aspect A25 is the print assembly of any of aspects A1 to A24, wherein the print assembly is mounted on a traversal stage that sets an index for the print assembly.

[0030] A twenty-sixth embodiment, A26, is a manufacturing apparatus including the print assembly of any of embodiments A1-A25 and at least one binder reservoir that provides binder material directly to at least one of the inlet manifold and the outlet manifold and receives binder material from at least one of the inlet manifold and the outlet manifold.

[0031] A twenty-seventh embodiment A27 is a method for clearing clogged printheads of a printing head assembly, comprising: an inlet manifold for delivering binder material to a plurality of printheads, each of the plurality of printheads coupled to the inlet manifold through a corresponding one of a plurality of inlet ports, one of a plurality of inlet valves provided for each of the plurality of inlet ports; and an outlet manifold for receiving unused binder material from the plurality of printheads, each of the plurality of printheads coupled to the outlet manifold through a corresponding one of a plurality of outlet ports, one of a plurality of outlet valves provided for each of the plurality of outlet ports. wherein the inlet manifold has a first pressure and the outlet manifold has a second pressure, a pressure differential exists between the inlet manifold and the outlet manifold, and a control unit closes at least one of the plurality of inlet valves to prevent binder material from flowing from the inlet manifold to the corresponding print head while at least another one of the plurality of inlet valves is open, and applies a positive pressure effective to adjust the pressure differential between the inlet manifold and the outlet manifold, thereby allowing binder material to flow only through the inlet port with the associated inlet valve in the open position, thereby clearing a clog of the associated print head.

[0032] Embodiment A28 is the method of embodiment A27, further including opening at least one closed inlet valve, closing at least one open inlet valve, and applying positive pressure effective to unclog a different one of the plurality of printheads.

[0033] Twenty-ninth embodiment A29 is the method of embodiment A28, wherein the positive pressure ranges from 0.7 psi to 2 psi, with normal operating pressures ranging from -1.0 psi to 0.0 psi, and the positive pressure is based on the number of inlet valves that are open.

[0034] A thirtieth aspect, A30, is the method of any of aspects A27-A29, further comprising closing all but one of the plurality of inlet valves, such that only one of the plurality of inlet valves is open.

[0035] A thirty-first embodiment, A31, is the method of any of embodiments A27-A30, further including activating a pump in a binder reservoir to direct binder material to the inlet manifold and the inlet valve in the open position to clear a clog in an associated printhead through a corresponding one of the plurality of inlet ports.

[0036] A thirty-second embodiment, A32, is the method of any of embodiments A27-A31, wherein the inlet manifold includes a first bypass port, the outlet manifold includes a second bypass port, and a bypass valve is associated with one of the first bypass port and the second bypass port, and the method further comprises closing each of the plurality of inlet valves and the plurality of outlet valves, opening the bypass valve, and applying a vacuum to remove air from the manifold assembly.

[0037] A thirty-third embodiment A33 is a method for circulating binder material through a print assembly, comprising: providing a manifold assembly including: an inlet manifold including an inlet reservoir and a plurality of inlet ports; an outlet manifold including an outlet reservoir and a plurality of outlet ports; a plurality of inlet valves in the inlet manifold; and a plurality of outlet valves in the outlet manifold, each of the plurality of inlet valves and the plurality of outlet valves independently operable to deliver binder material from at least one binder reservoir to the inlet manifold or the outlet manifold, and to receive binder material from the inlet manifold or the outlet manifold into the at least one binder reservoir; and applying a pressure differential across the inlet manifold and the outlet manifold, the pressure differential being controllable based on operation of each of the plurality of inlet valves and the plurality of outlet valves.

[0038] Thirty-fourth embodiment A34 is the method of embodiment A33, further including determining whether a level of binder material in at least one of the inlet manifold and the outlet manifold is above or below a predetermined threshold.

[0039] A thirty-fifth embodiment A35 is the method of any of embodiments A34, A35, further including determining that the level of binder material in the inlet manifold is above a predetermined threshold, and in response to the determination, reducing the rate at which binder material is supplied from the at least one reservoir into the inlet manifold, increasing the rate at which binder material is withdrawn from the inlet manifold toward the at least one reservoir, or both.

[0040] A thirty-sixth embodiment, A36, is the method of any of embodiments A33-A35, further including determining that a level of binder material in the inlet manifold is below a predetermined threshold, and in response to the determination, increasing a rate at which binder material is supplied from the at least one reservoir into the inlet manifold, decreasing a rate at which binder material is withdrawn from the inlet manifold toward a return reservoir, or both.

[0041] A thirty-seventh embodiment, A37, is the method of any of embodiments A33-A36, further including providing a fluid level float within the inlet manifold; determining when a level of binder material in the inlet manifold exceeds a predetermined threshold; and increasing an output rate of binder material from the outlet manifold to the at least one binder reservoir.

[0042] A thirty-eighth embodiment, A38, is the method of any of embodiments A33-A37, further including providing a fluid level float within the inlet manifold; determining when a level of binder material in the inlet manifold is below a predetermined threshold; and reducing an output rate of binder material from the outlet manifold to the at least one binder reservoir.

[0043] A thirty-ninth embodiment, A39, is a method of adjusting a printing head assembly including a plurality of printheads, the method comprising: an inlet manifold that delivers binder material to the plurality of printheads, each of the plurality of printheads coupled to the inlet manifold through a corresponding one of a plurality of inlet ports, one of a plurality of inlet valves provided for each of the plurality of inlet ports; and an outlet manifold that receives unused binder material from each of the plurality of printheads, each of the plurality of printheads coupled to the outlet manifold through a corresponding one of a plurality of outlet ports, one of a plurality of outlet valves provided for each of the plurality of outlet ports. and an outlet manifold, wherein the inlet manifold has a first pressure and the outlet manifold has a second pressure; and, by a control unit, closing all of the plurality of inlet valves and the plurality of outlet valves to prevent binder material from flowing from the inlet manifold to the corresponding printhead and from the corresponding printhead to the outlet manifold, opening bypass valves to allow binder material to flow from the inlet manifold to the outlet manifold, and varying at least one of the first pressure and the second pressure to establish a pressure differential between the inlet manifold and the outlet manifold.

[0044] A fortieth embodiment A40 is the method of embodiment A39, wherein the pressure differential during normal operation ranges from −1.0 psi to 0.0 psi, and the pressure differential during purging operation ranges from 0.7 psi to 2 psi.

[0045] A forty-first embodiment A41 is the method of any of embodiments A39, A40, wherein varying at least one of the first pressure and the second pressure includes providing binder material from the inlet manifold to the outlet manifold through the bypass valve.

[0046] A forty-second embodiment, A42, is the method of any of embodiments A39 to A41, wherein varying at least one of the first pressure and the second pressure includes applying a vacuum to at least one of the inlet manifold and the outlet manifold.

[0047] A forty-third embodiment, A43, is the method of any of embodiments A39-A42, wherein varying at least one of the first pressure and the second pressure includes supplying binder material from a supply reservoir to at least one of the inlet manifold and the outlet manifold. [Brief explanation of the drawings]

[0048] [Figure 1] FIG. 1 illustrates a schematic representation of an embodiment of a manufacturing apparatus according to one or more embodiments shown and described herein. [Figure 2] FIG. 2 schematically illustrates a perspective view of an embodiment of a print assembly including a printhead and an embodiment of a manifold assembly according to one or more embodiments shown and described herein. [Figure 3] FIG. 3 schematically depicts a partial perspective view of a bracket securing the manifold assembly of FIG. 2 according to one or more embodiments shown and described herein. [Figure 4] FIG. 4 schematically illustrates a partial perspective view of a bracket attached to the housing of the print assembly of FIG. 2 according to one or more embodiments shown and described herein. [Figure 5] FIG. 5 schematically illustrates a perspective view of the manifold assembly of FIG. 2 including multiple valves according to one or more embodiments shown and described herein. [Figure 6] FIG. 6 schematically depicts a bottom view of the manifold assembly of FIG. 2 according to one or more embodiments shown and described herein. [Figure 7] FIG. 7 schematically illustrates a partial end view of the print assembly of FIG. 2 according to one or more embodiments shown and described herein. [Figure 8A] FIG. 8A schematically depicts an exploded view of a valve of the manifold assembly of FIG. 5 according to one or more embodiments shown and described herein. [Figure 8B] FIG. 8B schematically depicts a perspective view of a plunger of a valve according to one or more embodiments shown and described herein. [Figure 9] FIG. 9 schematically illustrates a perspective view of an embodiment of an outlet manifold according to one or more embodiments shown and described herein. [Figure 10] FIG. 10 schematically illustrates a perspective view of an embodiment of a manifold assembly according to one or more embodiments shown and described herein. [Figure 11] FIG. 11 schematically depicts a partial side view of the manifold assembly of FIG. 10 according to one or more embodiments shown and described herein. [Figure 12] FIG. 12 schematically depicts a bottom view of the manifold assembly of FIG. 10 according to one or more embodiments shown and described herein. [Figure 13] FIG. 13 schematically depicts a diagram of material flow through a print assembly including the manifold assembly of FIG. 10 according to one or more embodiments shown and described herein. [Figure 14] FIG. 14 schematically illustrates a perspective view of an embodiment of a manifold assembly according to one or more embodiments shown and described herein. [Figure 15] FIG. 15 schematically depicts an exploded perspective view of the inlet manifold of the manifold assembly of FIG. 14 according to one or more embodiments shown and described herein. [Figure 16] FIG. 16 schematically depicts a perspective view of an outlet manifold of the manifold assembly of FIG. 14 according to one or more embodiments shown and described herein. [Figure 17]FIG. 17 schematically depicts a diagram of material flow through a print assembly including the manifold assembly of FIG. 16 according to one or more embodiments shown and described herein. [Figure 18] FIG. 18 schematically illustrates a perspective view of an embodiment of a manifold assembly according to one or more embodiments shown and described herein. [Figure 19] FIG. 19 schematically depicts a partial top view of the manifold assembly of FIG. 18 according to one or more embodiments shown and described herein. [Figure 20] FIG. 20 schematically depicts a bottom view of the top wall of the manifold assembly of FIG. 18 according to one or more embodiments shown and described herein. [Figure 21] FIG. 21 schematically illustrates a perspective view of a print assembly including an embodiment of a manifold assembly according to one or more embodiments shown and described herein. [Figure 22] FIG. 22 schematically depicts a perspective view of the manifold assembly of FIG. 21 according to one or more embodiments shown and described herein. [Figure 23] FIG. 23 schematically depicts a partial perspective view of the manifold assembly of FIG. 21 according to one or more embodiments shown and described herein. [Figure 24] FIG. 24 schematically depicts a partial side view of an embodiment of a manifold assembly including a pair of fluid level floats according to one or more embodiments shown and described herein. [Figure 25] FIG. 25 schematically depicts a partial cross-sectional view of a print assembly including an external level monitoring device according to one or more embodiments shown and described herein. [Figure 26] FIG. 26 schematically depicts a partial perspective view of a sight gauge apparatus according to one or more embodiments shown and described herein. DETAILED DESCRIPTION OF THE INVENTION

[0049] These and additional features provided by the embodiments described herein will be more fully understood in view of the following detailed description taken in conjunction with the drawings.

[0050] The embodiments set forth in the drawings are exemplary and illustrative in nature and are not intended to limit the subject matter defined by the claims. The following detailed description of exemplary embodiments can be understood when read in conjunction with the following drawings, in which like structure is indicated with like reference numerals and in which:

[0051] Reference will now be made in detail to embodiments of a manufacturing apparatus and its components, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. An embodiment of a print assembly, an example of which is shown schematically in FIG. 2, includes a manifold assembly including an inlet manifold and an outlet manifold. The inlet manifold includes an inlet reservoir and an inlet port. An inlet valve is provided at the inlet port of the inlet reservoir. The outlet manifold similarly includes an outlet reservoir and an outlet port. An outlet valve is provided at the outlet port of the outlet reservoir. A print head is in fluid communication with each of the inlet and outlet reservoirs, and the inlet and outlet valves are independently operable to allow material flow from the inlet reservoir to the print head and from the print head to the outlet reservoir, respectively.

[0052] Various embodiments of print assemblies for manufacturing devices, manufacturing apparatuses including print assemblies, and methods for using the same are described in further detail herein with specific reference to the accompanying drawings. It should be understood that the embodiments of the manufacturing apparatus shown and described herein may be configured and operable to build three-dimensional and / or non-three-dimensional objects or parts.

[0053] Ranges can be expressed herein as from "about" one particular value, and / or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values ​​are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. The beginning and end points of a range each have significance relative to the other point (the end point and the beginning point), and each have a significance independent of the other point.

[0054] It should be noted that the terms "substantially" and "about" may be utilized herein to express the inherent degree of uncertainty that may result from any quantitative comparison, value, measurement, or other representation. These terms are also utilized herein to express the degree to which a quantitative representation may vary from the stated reference without resulting in a change in the basic functionality of the subject matter in question.

[0055] Directional terms used herein, such as up, down, right, left, front, rear, top, upward, bottom, forward, backward, reverse, and back, are made solely with reference to the figures as drawn and are not intended to imply absolute orientation unless expressly stated otherwise.

[0056] Unless otherwise expressly stated, it is never intended that any method described herein be construed as requiring its steps to be performed in a particular order or as requiring a particular orientation of any device. Thus, if a method claim does not actually recite an order in which its steps should be followed, or if any apparatus claim does not actually recite an order or orientation for individual components, or if it is specifically stated otherwise in the claim or description that the steps are to be limited to a particular order or no particular order or orientation for the apparatus components is recited, then no order or orientation is intended to be inferred in any respect. This applies to any possible implicit basis for interpretation, including matters of logic regarding the arrangement of steps, operational flow, component order, or component orientation, plain meaning derived from grammatical organization or punctuation, and the number or type of embodiments described herein.

[0057] As used herein, the singular forms "a," "an," and the like include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "one" element includes aspects having two or more such elements unless the context clearly dictates otherwise.

[0058] manufacturing equipment SUMMARY OF THE INVENTION The embodiments described herein are directed to manufacturing apparatus (e.g., additive manufacturing apparatus) and components for manufacturing apparatus, particularly print assemblies for depositing binders and other jettable substances. Various embodiments described herein may be implemented to prevent, for example, spatial separation between print assembly nozzles and ink reservoirs, receptacle-to-receptacle leakage, and pressure fluctuations due to imperfections during print assembly calibration and unclog operations. While the techniques improved and described herein relate to manufacturing, it is understood that aspects of the techniques may have application in related industries, such as 2D printing.

[0059] Referring now to FIG. 1 , one embodiment of a manufacturing apparatus 100 is illustrated schematically. The manufacturing apparatus 100 includes a cleaning station 108, a build area 120, a feed platform 130, a recoat assembly 140, and a print assembly 150. The recoat assembly 140 and the print assembly 150 are coupled to a rail 104 of the manufacturing apparatus 100 and configured to translate along the rail 104 in response to actuation of a first actuator assembly 102. The first actuator assembly 102 may be configured to facilitate independent control of the recoat assembly 140 and the print assembly 150 along a work axis 116 of the manufacturing apparatus 100. The work axis 116 is also referred to herein as the “longitudinal axis” (i.e., extending along the + / −X axis of the coordinate system as shown in the figure). This allows the recoat assembly 140 and the print assembly 150 to traverse the working axis 116 of the manufacturing apparatus 100 in the same and / or opposite directions, and allows the recoat assembly 140 and the print assembly 150 to traverse the working axis 116 of the manufacturing apparatus 100 at different and / or the same speeds.

[0060] In the embodiment described herein, the cleaning station 108, build area 120, feed platform 130, recoat assembly 140, and print assembly 150 are arranged in series along the work axis 116 of the manufacturing apparatus 100 between a home position 151 of the print assembly 150 located near the −X end of the work axis 116 and a home position 153 of the recoat assembly 140 located near the + / −X end of the work axis 116. In an embodiment, the build area 120 is arranged between the cleaning station 108 and the feed platform 130 along the work axis 116 of the manufacturing apparatus 100.

[0061] In embodiments, the second actuator assembly 103 may be built to facilitate independent control of the print assembly 150 along a horizontal axis (i.e., extending along the + / - Y axis of the coordinate system as shown) that is generally perpendicular to the vertical axis (i.e., the work axis 116). The first actuator assembly 102 and the second actuator assembly 103 are generally referred to as a printhead position control assembly. That is, the printhead position control assembly includes the first actuator assembly 102 configured to move the printhead along the vertical axis and the second actuator assembly 103 configured to move the printhead along the horizontal axis. The printhead position control assembly may be controlled via signals generated by a control system 10, such as an electronic control unit. The electronic control unit may include a processor and non-transitory computer-readable memory.

[0062] Print assembly 150 includes, among other features, a support bracket 152, a printing head 154, and a plurality of print heads 156. Support bracket 152 is movably coupled to rail 104 and a first actuator assembly 102 of manufacturing apparatus 100, and printing head 154 is movably coupled to support bracket 152 via a second actuator assembly 103.

[0063] Each printhead 156 includes one or more jet nozzles. When multiple jet nozzles are incorporated into a printhead 156, the jet nozzles are spaced apart from one another. The jet nozzles are spaced apart from one another transverse to the longitudinal axis, and the distance from a first jet nozzle to a second jet nozzle disposed adjacent to the first jet of the plurality of jets defines a jet spacing. By way of example only, each printhead 156 can include a plurality of jet nozzles ranging from about 5,000 to about 6,000 nozzles, with each jet nozzle spaced apart from one another by about 1 / 1150 of an inch. Other jet nozzle spacings are possible and contemplated.

[0064] The recoat assembly 140 is built to facilitate dispensing of build material 40 onto the build region 120 and the supply platform 130. The build region 120 is coupled to a build platform actuator 122, which facilitates raising and lowering the build region 120 in a direction perpendicular to the work axis 116 of the manufacturing apparatus 100 (i.e., a direction parallel to the + / -Z axes of the coordinate axes shown in the figures). The build region 120 and the build platform actuator 122 are disposed within a build receptacle 124 located below the work axis 116 of the manufacturing apparatus 100 (i.e., in the -Z direction of the coordinate axes shown in the figures). During operation of the manufacturing apparatus 100, the build region 120 is retracted into the build receptacle 124 by operation of the build platform actuator 122 after each layer of binder material 50 is deposited on the build material 40 located on the build region 120.

[0065] 1 , the feed platform 130 is coupled to a feed platform actuator 132 to facilitate raising and lowering the feed platform 130 vertically (i.e., parallel to the + / −Z axes of the coordinate axes shown in the figure) relative to the work axis 116 of the manufacturing apparatus 100. The feed platform 130 and feed platform actuator 132 are disposed within a feed receptacle 134 located below the work axis 116 of the manufacturing apparatus 100 (i.e., in the −Z direction of the coordinate axes shown in the figure). During operation of the manufacturing apparatus 100, the feed platform 130 is raised toward the work axis 116 of the manufacturing apparatus 100 relative to the feed receptacle 134 by operation of the feed platform actuator 132 after a layer of build material 40 is dispensed from the feed platform 130 to the build zone 120, as described in further detail herein. However, it should be understood that in other embodiments, the manufacturing apparatus 100 does not include a feed platform 130, such as, for example, but not limited to, embodiments in which build material is supplied to the build zone 120 using a build material hopper.

[0066] As described in more detail herein, the print assembly 150 is configured to facilitate deposition of binder material 50 and / or other jettable composition materials (e.g., ink, fluid medium, colorant, nanoparticles, fluorescent particles, sintering aids, anti-sintering aids, etc.) onto the layer of build material 40 in the build region 120 as the print assembly 150 traverses the build region 120 along the work axis 116 of the manufacturing apparatus 100.

[0067] 1 , the cleaning station 108 is located near one end of the work axis 116 of the manufacturing apparatus 100 and is positioned at the same location as the home position 151 where the print assembly 150 is positioned or “parked” before and after depositing binder material 50 onto a layer of build material 40 disposed on the build region 120. The cleaning station 108 may include one or more cleaning sections to facilitate cleaning of the print assembly 150, and particularly the multiple printheads 156 of the print assembly 150, between deposition operations. The cleaning sections may include, for example, but are not limited to, a soaking station containing a cleaning solution for dissolving excess binder material 50 from the multiple printheads 156, a wiping station for removing excess binder material 50 from the multiple printheads 156, a jetting station for purging the binder material 50 and cleaning solution from the multiple printheads 156, a capping station for maintaining moisture within the multiple jet nozzles of the multiple printheads 156, or various combinations thereof. The print assembly 150 may be transitioned between the cleaning sections by the first actuator assembly 102. In embodiments, manufacturing apparatus 100 may include a jetting test area located proximate cleaning station 108 and / or an end of work axis 116 adjacent home position 151. While not shown, it should be understood that the jetting test area of ​​manufacturing apparatus 100 may be configured to facilitate binder material deposition by print assembly 150 prior to deposition along build region 120. Additional information regarding cleaning stations within manufacturing apparatuses can be found in PCT Application No. PCT / US20 / 34144, filed May 22, 2020, entitled "Cleaning Apparatus for Additive Manufacturing Apparatus and Method of Use Thereof," which is incorporated herein by reference in its entirety.

[0068] 1 , the manufacturing apparatus 100 may further include a control system 10 communicatively coupled to the first actuator assembly 102, the second actuator assembly 103, the recoat assembly 140, and / or the print assembly 150. As described in more detail herein, in embodiments, the control system 10 may be coupled to, among other things, one or more valves of a manifold assembly 160 of the print assembly 150. While in embodiments, the control system 10 is coupled to the manufacturing apparatus 100 via a communication conduit 12, it should be understood that in other embodiments, the control system 10 may be communicatively coupled to the manufacturing apparatus 100 via various other means or systems, such as, for example, a wireless connection. The control system 10, which may also be referred to as an electronic control unit, comprises a processor and a non-transitory memory including computer-readable and executable instructions stored thereon. Any operation of the manufacturing apparatus 100, including those described herein, may be performed by computer-readable and executable instructions (e.g., opening and closing a valve in the manifold assembly 160) stored in the non-transitory memory of the control system 10, when executed by the processor of the control system 10. For example, one or more actuators may be actuated by computer-readable and executable instructions stored in non-transitory memory of the control system 10, which, when executed by a processor of the control system 10, may cause the valves of the manifold assembly 160 to operate in the manner described herein.

[0069] In an embodiment, control system 10 may further be communicatively coupled to computing device 15, optionally via network 16 or directly via a communications link such as a wired or wireless connection. Computing device 15 may be configured to perform processes such as generating executable instructions for building components using manufacturing apparatus 100, such as by implementing a CAD or other related three-dimensional drafting and rendering system, a slicing engine, etc.

[0070] 1 , manufacturing apparatus 100 further includes at least one supply reservoir 110 and at least one return reservoir 112 fluidly coupled to manifold assembly 160 of print assembly 150 via one or more conduit lines 111, 113, respectively. In embodiments, supply reservoir 110 is highly pressurized to force binder material into print head 154. Although supply reservoir 110 and return reservoir 112 are shown and discussed herein as separate components for storing binder material, in embodiments, supply reservoir 110 and return reservoir 112 may be the same reservoir, such that binder material from supply reservoir 110 is circulated back to supply reservoir 110 rather than to a separate return reservoir 112.

[0071] As described in more detail below, the manifold assembly 160 includes an inlet reservoir and an outlet reservoir for storing binder material. Each of the inlet and outlet reservoirs may be in fluid communication with the plurality of printheads 156. In particular, the supply reservoir 110 and the return reservoir 112 are fluidly coupled via the manifold assembly 160 to each of the plurality of printheads 156 disposed within the printing head 154 of the print assembly 150. The plurality of printheads 156 are primed for recirculation such that binder material is initially supplied to the plurality of printheads 156 and any unused binder material is drawn back from the plurality of printheads 156. As described in more detail below, the binder material is initially delivered from the supply reservoir 110 to the inlet reservoir of the manifold assembly 160 and then delivered from the inlet reservoir of the manifold assembly 160 to the plurality of printheads 156. Any unused binder material is then drawn from the multiple printheads 156 into an outlet reservoir of the manifold assembly 160. The unused binder material is then drawn from the outlet reservoir and delivered into the return reservoir 112.

[0072] In embodiments, the first conduit line 111 and the second conduit line 113 may be coupled to one another via a coupling mechanism, such as, for example, a manifold, a valve, or the like. In this case, the reservoirs 110, 112 may be in fluid communication with the coupling mechanism via the conduit lines 111, 113, and the coupling mechanism may include a third conduit line coupled thereto and extending to the printing heads 154. The coupling mechanism may be configured to selectively transition fluid communication between the fluid reservoirs 110, 112 and the printing heads 154 in response to actuation of the coupling mechanism, such that the plurality of print heads 156 receive one of the first material 114 (e.g., fresh binder solution from the supply reservoir 110) or the second material 115 (e.g., recycled binder solution from the return reservoir 112). It should be appreciated that the coupling mechanism may be further configured to facilitate simultaneous fluid communication between the supply reservoir 110 and the return reservoir 112 and the printing heads 154, such that multiple print heads 156 simultaneously receive binder material from the supply reservoir 110 and the return reservoir 112. Such a configuration may, for example, allow for faster refilling of the manifold assembly 160 during and after purging, as described below.

[0073] Typical Print Assembly 2, one embodiment of a print assembly 150 is shown. The print assembly 150 includes a housing 202 that at least partially encloses a printing head 154 and a manifold assembly 160. The printing head 154 includes multiple print heads 156 in fluid communication with the manifold assembly 160 to facilitate the supply of binder material from the manifold assembly 160 to each print head 156 and the recycling of binder material from each print head 156 to the manifold assembly 160.

[0074] The printing head 154 includes a first printhead row 205 and a second printhead row 207 disposed along the bottom edge of the printing head 154. The printhead rows 205, 207 are each sized and shaped to receive at least one printhead 156 therein, and in embodiments, each receives multiple printheads 156. The printhead rows 205, 207 are disposed parallel to one another along the bottom edge of the printing head 154 and are sequentially aligned with one another in a collinear array. In embodiments, the printheads 156 can move along their corresponding printhead rows 205, 207, while in other embodiments, the printheads 156 can be fixed within the printing head 154.

[0075] In embodiments, printing head 154 may include additional or fewer rows of printheads 156 than the embodiment shown in Figure 2. For example, in embodiments, printing head 154 of print assembly 150 may include one row of printheads 156 or three or more rows of printheads 156. Thus, it should be understood that printing head 154 may include one or more rows of printheads 156, each having one or more printheads 156. Additionally, each of first printhead row 205 and second printhead row 207 may include more or fewer printheads 156 than shown.

[0076] The plurality of printheads 156 are exposed at the bottom end of the housing 202. In embodiments, the plurality of printheads 156 in the first printhead row 205 and the second printhead row 207 are aligned with the bottom end of the housing 202 such that the faceplates of the plurality of printheads 156 may be flush with the bottom end of the housing 202. In embodiments, the faceplates of the plurality of printheads 156 may be offset relative to each other and relative to the bottom end of the housing 202.

[0077] It is contemplated that in embodiments, print assembly 150 may include additional features not described herein. In particular, the manifold assembly described below may be adapted for inclusion in any one of a number of different print assemblies, which may then be used in any one of a number of additive manufacturing devices.

[0078] General Manifold Assembly 2 , the manifold assembly 160 of various embodiments generally includes an inlet manifold 210 and an outlet manifold 212. The inlet manifold 210 includes a first wall 214, a second wall 216, a top wall 218, a bottom wall 220, and a pair of end walls 222, 224. Similarly, the outlet manifold 212 includes a first wall 226, a second wall 228, a top wall 230, a bottom wall 232, and a pair of end walls 234, 236. Each of the inlet manifold 210 and the outlet manifold 212 may be a substantially one-piece monolithic structure, such as may be formed by additive manufacturing or injection molding having one or more common walls, or may be formed separately and then sealed together. In embodiments in which the inlet manifold 210 and the outlet manifold 212 are airtight to one another (e.g., each manifold 210, 212 includes its own first wall, second wall, and pair of end walls, and does not have a common wall), leakage between the inlet manifold 210 and the outlet manifold 212 may be prevented. Furthermore, in some such embodiments, it is contemplated that the inlet manifold 210 and the outlet manifold 212 may be separable from one another (as shown in FIG. 3 ), thus allowing either the inlet manifold 210 or the outlet manifold 212 to be replaced or repaired without manifold 210 or 212 being manipulated. However, it should be understood that in embodiments, the inlet manifold 210 and the outlet manifold 212 may be permanently fixed to one another or formed from a single piece. In some such embodiments, the inlet manifold 210 and the outlet manifold 212 may share a common wall separating the inlet manifold 210 from the outlet manifold 212.

[0079] 3 and 4, in an embodiment, the print assembly 150 further includes a retainer bracket 342 for securing the inlet manifold 210 and the outlet manifold 212 in a fixed position relative to the housing 202. In an embodiment, the retainer bracket 342 includes a base member 344 and a pair of side arms 346, 348 extending proximate opposite ends of the base member 344 and positioned on either side of the manifold assembly 160. Each of the side arms 346, 348 includes a finger 350 formed on an end of the side arm 346, 348 opposite the base member 344 that conforms to the shape of the manifold assembly 160. Thus, the pair of side arms 346, 348 prevent the inlet manifold 210 and the outlet manifold 212 from separating from each other when the retainer bracket 342 is utilized.

[0080] In an embodiment, the retainer bracket 342 secures the manifold assembly 160 to the housing 202 and further includes at least one adjustment knob 352 for adjusting the position of the manifold assembly 160 relative to the housing 202. For example, in an embodiment, each of the side arms 346, 348 of the retainer bracket 342 is disposed adjacent opposite ends of the base member 344 and includes one or more adjustment knobs 352 insertable into respective slots 354 formed in side members 356 of the housing 202. The adjustment knobs 352 can be threadedly engaged with the retainer bracket 342 to provide a clamping load between the retainer bracket 342 and the housing 202.

[0081] 5 and 6 , the inlet manifold 210 of the manifold assembly 160 generally includes an inlet reservoir 238 defined by a first wall 214, a second wall 216, a top wall 218, a bottom wall 220, and a pair of end walls 222, 224 of the inlet manifold 210. In some embodiments, the inlet manifold 210 includes a pair of threaded end caps 240 having O-rings (not shown) insertable into the inlet manifold 210 at opposite ends of the inlet reservoir 238. The end walls 222, 224 are provided on each of the end caps 240 and secured to the first wall 214, the second wall 216, and the top wall 218 by a plurality of threaded fasteners to further seal the inlet reservoir 238. In embodiments, the end walls 222, 224 may be permanently sealed to the inlet manifold 210 by any suitable method, such as, for example, PVC welding. In some embodiments, O-rings may be provided between the end walls 222 , 224 and the adjacent walls of the inlet manifold 210 .

[0082] A supply port 242 is formed in the bottom wall 220 of the inlet manifold 210 and is in fluid communication with the inlet reservoir 238. A supply fitting 244 is coupled to the supply port 242. As used herein, the term "port" refers to an opening or orifice formed through a surface or wall of a structure, and the term "fitting" refers to any suitable connection member provided at the port and connectable to a tube or conduit line for fluidly connecting the tube to the interior of the structure. The inlet manifold 210 also includes at least one inlet port 266 formed in the bottom wall 220 of the inlet manifold 210 in fluid communication with the inlet reservoir 238. The inlet fitting 268 is coupled to the inlet port 266. In an embodiment, the inlet manifold 210 may include multiple inlet ports 266 formed in the bottom wall 220 of the inlet manifold 210 and in fluid communication with the inlet reservoir 238.

[0083] In use, binder material flows from the inlet reservoir 238 through the inlet port 266 and the inlet fitting 268 and to each printhead 156 via the inlet tube 270. An inlet fitting 268 may be coupled to each inlet port 266 and connected to each printhead 156 via the associated inlet tube 270 to allow binder material to flow from the inlet reservoir 238 to each printhead 156. As described above, when the manifold assembly 160 is provided within the housing 202 of the print assembly 150, the length of the inlet tube 270 may be significantly reduced, thereby reducing the risk of adverse pressure fluctuations through the inlet tube 270. In embodiments such as the embodiment shown in FIG. 7, the inlet fittings 268 may be oriented in a staggered arrangement to accommodate the spatial arrangement of the printheads 156. Specifically, in embodiments, the inlet fittings 268 may be alternated between being directed to different rows of printheads 156. An inlet vacuum 272 is provided in the top wall 218 of the inlet manifold 210 and is in fluid communication with the inlet reservoir 238 to normalize and / or supply pressure within the inlet reservoir 238 and to provide ventilation.

[0084] 5 , in an embodiment, the inlet manifold 210 also includes at least one fluid level float 274 disposed within the inlet reservoir 238. As described in more detail herein, the at least one fluid level float 274 within the inlet manifold 210 is configured to sense the level of binder material within the inlet reservoir 238 and to send a signal to the control system 10 of the manufacturing apparatus 100 to perform an action and / or alarm function when the level of binder material within the inlet reservoir 238 falls below or exceeds a predetermined threshold. As a non-limiting example of an action or alarm function, the signal may instruct the print assembly 150 to halt printing or build operations for a predetermined period of time to allow for recovery or maintenance.

[0085] Similar to the inlet manifold 210, the outlet manifold 212 includes an outlet reservoir 286 defined by a first wall 226, a second wall 228, a top wall 230, a bottom wall 232, and a pair of end walls 234, 236. The outlet reservoir 286 stores unused binder material received from the printheads 156 (e.g., binder material not jetted by the printheads 156). A return port 300 is formed in the bottom wall 232 of the outlet manifold 212 and is in fluid communication with the outlet reservoir 286. A return fitting 302 is coupled to the return port 300. The outlet manifold 212 also includes at least one outlet port 310 formed in the bottom wall 232 of the outlet manifold 212 that is in fluid communication with the outlet reservoir 286. An outlet fitting 312 is coupled to the outlet port 310. In embodiments, the outlet manifold 212 may include a plurality of outlet ports 310 formed in the bottom wall 232 of the outlet manifold 212 and in fluid communication with the outlet reservoir 286. In some embodiments, the outlet manifold 212 includes a pair of threaded end caps 241 with O-rings (not shown) insertable into the outlet manifold 212 at either end of the outlet reservoir 286.

[0086] In use, binder material flows from each printhead 156 through outlet ports 310 and outlet fittings 312 via outlet tubing 314 to the outlet reservoir 286. An outlet fitting 312 may be coupled to each outlet port 310 and connected to each printhead 156 via associated outlet tubing 314 to allow binder material to flow from the outlet reservoir 286 to each of the printheads 156. Similar to the inlet fittings 268, the outlet fittings 312 may be oriented in an alternating arrangement to accommodate the spatial arrangement of the printheads 156, as shown in FIG. 7. Specifically, in embodiments, the outlet fittings 312 may be alternated between being directed to different rows of printheads 156. To normalize and / or supply pressure within the inlet reservoir 238 and to provide ventilation, an outlet vacuum 316 is provided in the top wall 230 of the outlet manifold 212, as shown in FIG. 5, and is in fluid communication with the outlet reservoir 286.

[0087] The inlet vacuum 272 and the outlet vacuum 316 create a pressure differential between the inlet manifold 210 and the outlet manifold 212 to control the flow of binder material to and from each of the print heads 156 through the inlet port 266 and the outlet port 310. In some embodiments, during normal operation, the normal pressure differential between the inlet manifold 210 and the outlet manifold 212 can be greater than −1.0 pounds per square inch (psi) and less than or equal to 0.0 psi. This provides a negative pressure within the inlet manifold 210 and the outlet manifold 212 to create a vacuum. During a purge or unclog operation to clear a clogged print head 156, the purge pressure differential between the inlet manifold 210 and the outlet manifold 212 can be increased from the normal pressure differential. In some embodiments, the purge pressure differential can be up to 2.0 psi or more. However, the specific pressure differential can vary depending on the particular embodiment. Additionally, the particular pressure differential may be based on the particular requirements of the active (open) printheads 156, i.e., the amount of binder material required for each printhead 156. Furthermore, the particular pressure differential may be based on the size of the inlet manifold 210 and outlet manifold 212 relative to the size of the nozzles of the printheads 156.

[0088] 5 , similar to the inlet manifold 210, the outlet manifold 212 can include at least one fluid level float 318 disposed within the outlet reservoir 286. The at least one fluid level float 318 within the outlet manifold 212 is configured to sense the level of binder material within the outlet reservoir 286 and to send a signal to the control system 10 of the manufacturing apparatus 100 to perform an action and / or alarm function when the level of binder material within the outlet reservoir 286 falls below or exceeds a predetermined threshold. The fluid level float 274 within the inlet manifold 210 and the fluid level float 318 within the outlet manifold 212 can be, for example, an optical device, an ultrasonic device, or the like. It should be further noted that the fluid level within each of the inlet manifold 210 and the outlet manifold 212 can be monitored by an external sensor, such as, for example, an optical device, an ultrasonic device, or the like, in addition to or instead of the fluid level floats 274, 318, and communicatively coupled to the control system 10.

[0089] In an embodiment, the fluid level floats 274, 318 of the inlet manifold 210 and the outlet manifold 212 may each include a temperature sensor for detecting the temperature of the binder material therein. However, it should be understood that in an embodiment, the temperature sensors may be separate from the fluid level floats 274, 318 and communicatively coupled to the control system 10. The temperature sensors of each of the inlet manifold 210 and the outlet manifold 212 may be configured to detect the temperature of the binder material and send a signal to the control system 10 to activate an alarm and / or cause the manifold assembly to stop printing operations if the binder temperature exceeds or falls below a threshold temperature.

[0090] Refilling the inlet manifold 210 can result in pressure fluctuations within the inlet manifold 210 and the outlet manifold 212, which can adversely affect print quality during a printing operation. Therefore, in an embodiment, the fluid level floats 274, 318 each have a control relay to prevent the inlet manifold 210 and the outlet manifold 212 from refilling during a printing operation. Specifically, the fluid level float 274 does not send a signal to allow additional binder material to flow into the inlet reservoir 238 while the manifold assembly 160 is actively performing a printing operation, i.e., while the print assembly 150 ( FIG. 1 ) is moving along the work axis 116 across the build region 120. Similarly, the fluid level float 318 does not send a signal to allow additional binder material to flow out of the outlet reservoir 286 while the manifold assembly 160 is actively performing a printing operation. Rather, the control relay for the fluid level float 274 , 318 delays sending a signal until the manifold assembly 160 has passed the build area 120 , ie, returned to the home position 151 .

[0091] 5 , the manifold assembly 160 includes at least one valve 330 operable between an open position to allow or control the flow of binder material through a portion of the manifold assembly 160 and a closed position to prevent the flow of binder material through a portion of the manifold assembly 160. As used herein, the term “control” when referring to a valve controlling the flow of binder material may be understood as allowing and / or preventing the flow of binder material. Furthermore, in embodiments, controlling the flow of binder material may refer to decreasing and / or increasing the flow rate or volume of binder material. It should be understood that any number of valves 330 may be provided to selectively and individually allow the flow of binder material both in and out of the ports of the inlet reservoir 238 and the outlet reservoir 286. In various embodiments described herein, at least one valve 330 is provided within the manifold assembly 160.

[0092] 5 and 6 , the inlet manifold 210 includes at least one valve 330 associated with each inlet port 266 to allow flow of binder material from the inlet reservoir 238 through the inlet port 266 to each printhead 156. In an embodiment, the inlet manifold 210 includes a valve 330 associated with each one of the multiple inlet ports 266. The outlet manifold 212 also includes at least one valve 330 associated with each outlet port 310. In an embodiment, the outlet manifold 212 includes a valve 330 associated with each one of the multiple outlet ports 310.

[0093] The valve 330 can be configured in any one of several valve configurations. As shown in FIG. 8A , the valve 330 generally includes a receptacle 332 and a plunger 334 received within the receptacle 332. In one embodiment, the valve 330 is a pneumatic actuator including a pair of pressure ports 336, a first of which is utilized to pneumatically move the plunger 334 to a raised position, and a second of which is utilized to pneumatically move the plunger 334 to a lowered position. In another embodiment, the valve 330 is an electric actuator. When the valve 330 is in an open position, the plunger 334 is moved toward a raised position and away from an associated port to allow binder material to flow through the port. When the valve 330 is in a closed position, the plunger 334 is moved toward a lowered position and toward an associated port to prevent binder material from flowing through the associated port. In another embodiment, the plunger 334 may be operated electronically by a control system without the pair of pressure ports 336. The control system 10 may electronically operate the plungers 334 by sending signals to move the plungers 334 toward or away from their respective ports, as discussed herein.

[0094] Referring now to FIG. 8B, plunger 334 is shown in more detail. In an embodiment, plunger 334 includes an outer member 341 having a first end 343 and an opposite second end 345. Outer member 341 can be formed from steel, stainless steel, aluminum, or the like. A bore 347 can be formed in second end 345 of outer member 341 and extend toward first end 343. A recess 349 is also formed in second end 345 of outer member 341 surrounding bore 347. A groove 351 is formed proximate first end 343 of outer member 341 and circumscribes the circumference of outer member 341. As shown in FIG. 8A, O-ring 338 is disposed in groove 351 to form an airtight seal with receptacle 332. In an embodiment, plunger 334 further includes an insert 353 disposable in bore 347 of outer member 341. The insert 353 may be formed from polyvinyl chloride (PVC) or the like. The insert 353 includes a first end 355 and an opposite second end 357 having a threaded groove 359 formed therein and extending toward the first end 355 of the insert 353. The insert 353 has an outer diameter corresponding to the inner diameter of the outer member 341 so that the insert 353 may be press-fit into the bore 347 of the outer member 341. Thus, when the insert 353 is positioned within the bore 347 formed in the outer member 341, an O-ring 361 may be provided within the recess 349 of the second end 345 of the outer member 341. Threads 363 then thread into the groove 359 formed in the insert 353 to retain the O-ring 361 within the recess 349 of the outer member 341. Thus, the O-ring 361 forms a fluid-tight seal between the plunger 334 and an associated port when the plunger 334 is lowered and the valve 330 is in the closed position.

[0095] Although not shown, in some embodiments, insert 353 may not be provided, and thread 363 may thread directly into a groove formed in outer member 341. In other embodiments, a plug may be provided having a threaded outer surface that threadingly engages the threaded inner surface of outer member 341. In this embodiment, the plug may be formed from steel, stainless steel, aluminum, or the like. The end of the plug may have a groove formed therein that extends from second end 345 of outer member 341 when positioned therein to retain O-ring 361 at second end 345 of outer member 341. Finally, in some embodiments, a sleeve may be provided and dimensioned to fit over at least a portion of the outer surface of outer member 341, particularly second end 345 of outer member 341. In this embodiment, the sleeve eliminates the need for O-ring 361, insert 353, and thread 363 to retain O-ring 361 on outer member 341 of plunger 334. Rather, the sleeve itself forms a fluid-tight seal between the plunger 334 and the associated port when the plunger 334 is lowered and the valve 330 is in the closed position.

[0096] Referring again to FIG. 8A , in some embodiments, the valve 330 includes a proximity sensor 340 that determines whether the valve 330 is in an open or closed position by sensing whether the plunger 334 is in the raised or lowered position, respectively. An opening 331 is provided in the top surface 333 of the receptacle 332, through which a sensing portion 335 of the proximity sensor 340 extends. Thus, when the plunger 334 moves toward the raised position within the receptacle 332, the sensing portion 335 identifies that the plunger 334 is in the raised position. The sensing portion 335 identifying that the plunger 334 is in the raised position indicates that the valve 330 is in the open position. When the plunger 334 moves toward the lowered position within the receptacle 332, the sensing portion 335 identifies that the plunger 334 is in the lowered position. Thus, the sensing portion 335 identifying that the plunger 334 is in the lowered position indicates that the valve 330 is in the closed position. The proximity sensor 340 may identify the position of the plunger 334 based on any suitable engagement, such as, for example, magnetic, electrical, or physical communication. Thus, the sensing portion 335 may be configured to determine the position of the plunger 334 at a position between the raised and lowered positions to identify that the valve 330 may be in a partially closed position.

[0097] Alternatively, valve 330 can be controlled by control system 10 to position valve 330 a controlled amount between an open position and a closed position. It should be understood that plungers 334 of valve 330 are mounted within inlet manifold 210 and outlet manifold 212 and are movable therein to open and close corresponding ports. However, receptacles 332 are mounted external to inlet manifold 210 and outlet manifold 212. Thus, valve 330 can be accessed for repair or maintenance purposes by removing receptacles 332 to access plungers 334.

[0098] 9, as an alternative to the plunger and receptacle type valves described above, in embodiments, inlet manifold 210 and / or outlet manifold 212 may include valves in the form of camshaft assemblies 360 for opening and closing the respective inlet ports 266 and / or outlet ports 310. As shown, camshaft assembly 360 is shown within outlet manifold 212. However, it should be understood that the present disclosure is equally applicable to camshaft assemblies provided within inlet manifold 210.

[0099] In various embodiments, a camshaft assembly 360 includes a camshaft 362 extending longitudinally through the outlet reservoir 286 and extending through one of the rotatable end walls 234, 236 along axis A. The camshaft 362 includes at least one lobe 364 extending radially therefrom and positioned to correspond with an associated outlet port 310. The lobe 364 has a distal end 366 that conforms to the shape of the outlet port 310 such that when the camshaft 362 is rotated to a position where the distal end 366 of the lobe 364 engages the outlet port 310, the outlet port 310 is closed (e.g., blocked by the distal end 366) and binder material cannot flow through the outlet port 310. Alternatively, the camshaft 362 can be rotated to disengage the distal end 366 of the lobe 364 from engagement with the outlet port 310, allowing binder material to flow through the outlet port 310.

[0100] If the outlet manifold 212 includes multiple outlet ports 310, the camshaft 362 may include multiple lobes 364, with each lobe 364 corresponding to an associated outlet port 310. In embodiments, the lobes 364 may each be positioned at the same angle or orientation relative to the camshaft 362, such that each of the outlet ports 310 may be simultaneously opened and closed. In embodiments, the lobes 364 may be positioned on the camshaft 362 at different angles such that when one or more lobes 364 are positioned to close a corresponding outlet port 310, one or more other lobes 364 are positioned to open other outlet ports 310. For example, each lobe 364 on the camshaft 362 may be positioned at a different angle such that with each incremental rotation of the camshaft 362, a different outlet port 310 is closed.

[0101] It should be understood that other combinations of lobe arrangements are within the scope of the present disclosure. For example, the first set of lobes 364 may be arranged at a first angle, and the second set of lobes 364 may be arranged at a second angle. Thus, when the camshaft 362 is rotated to a first position, the outlet ports 310 corresponding to the first set of lobes 364 are closed, and when the camshaft 362 is rotated to a second position, the outlet ports 310 corresponding to the second set of lobes 364 are closed. This allows for various combinations of outlet ports 310 to be opened and / or closed at any given time, rather than just opening and / or closing a single outlet port 310 at a time. Although not shown, the camshaft 362 may be connected by a motor for rotating the camshaft 362.

[0102] Additionally, in embodiments, each outlet port 310 may include two or more associated lobes 364, such that the outlet port 310 may be closed more than once with each complete rotation of the camshaft 362. By providing more than one associated lobe 364 within each outlet port 310, this allows for additional combinations of outlet ports 310 that may be closed at any one position of the camshaft 362 about the axis A.

[0103] In various implementations described herein, whether in the form of a plunger and receptacle, a lobe and camshaft, or another type of valve, the valve 330 is adapted to facilitate purging and / or unclogging of the printheads 156 of the printing head 154 when at least one of the nozzles of the associated printhead 156 is at least partially clogged with binder material. When the nozzles of a printhead 156 are at least partially clogged with binder material, this can result in irregular printing and uneven distribution of binder material over the build area relative to other printheads 156 that are not clogged.

[0104] As a non-limiting example, to clear a clog in a printhead 156 of a printing head 154 during a purge or unclog operation, the valve 330 associated with the inlet port 266 of the clogged printhead 156 may be positioned in an open position. Similarly, the valve 330 associated with the outlet port 310 of the clogged printhead 156 may be positioned in an open position. In embodiments, each of the valves 330 associated with the other inlet ports 266 and outlet ports 310 of the other, unclogged printheads 156 may be placed in a closed position. The pressure differential between the inlet manifold 210 and the outlet manifold 212 resulting from operation of the inlet vacuum 272 of the inlet manifold 210 and the outlet vacuum 316 of the outlet manifold 212 is then increased from a normal pressure differential to a purge pressure differential. In some embodiments, as discussed herein, the normal pressure differential during normal operation of the printing head 154 with all valves 330 in the open position is greater than −1.0 psi and less than or equal to 0.0 psi. In some embodiments, during a purge or clog removal operation, the purge pressure differential is up to 2.0 psi. Thus, when the inlet vacuum 272 and the outlet vacuum 316 increase the pressure differential between the inlet manifold 210 and the outlet manifold 212 and provide binder material from the pressurized supply reservoir 110 into the inlet reservoir 238, the binder material is directed only through the inlet port 266 and the outlet port 310 that are in the open position, i.e., the inlet port 266 and the outlet port 310 associated with the clogged printhead 156. This focuses the pressure on the inlet port 266 with the valve 330 in the open position. Thus, the inlet port 266, and therefore the associated printhead 156, experiences an increased amount of pressure compared to the amount of pressure experienced when each of the valves 330 at the inlet port 266 is in the open position.

[0105] It should be understood that any combination of printheads 156 can be subjected to this de-clogging process by placing some of the valves 330 in an open position and other valves 330 in a closed position. For example, several of the printheads 156 can be simultaneously subjected to this de-clogging process by opening only the valves 330 of the inlet ports 266 and outlet ports 310 associated with the printheads 156 to clear the clogs. However, it should be understood that the more valves 330 that are opened, the less pressure will flow through each of the associated inlet ports 266, unless the overall pressure differential within the manifold assembly 160 is increased to compensate for the reduction in pressure.

[0106] H3 embodiment 10-13, another embodiment of a manifold assembly 160A is shown. It should be understood that the manifold assembly 160A is substantially similar to the manifold assembly 160 discussed herein, and thus like portions of the inlet manifold 210 and the outlet manifold 212 are referred to herein with like reference numerals.

[0107] 10-13, the manifold assembly 160A includes a supply port 242 in fluid communication with the inlet reservoir 238 and a return port 254 in fluid communication with the inlet reservoir 238. A return fitting 256 is coupled to the return port 254.

[0108] 10-13, the inlet manifold 210 of the manifold assembly 160A includes a first fluid level float 274, sometimes referred to herein as a high level fluid float 274, and a second fluid level float 276. The second fluid level float 276 may be referred to as a low fluid level float or a control fluid level float. The first fluid level float 274 extends through the top wall 218 of the inlet manifold 210, and the second fluid level float 276 extends through the bottom wall 220 of the inlet manifold 210.

[0109] The inlet manifold 210 of the manifold assembly 160A also includes a first upper sight gauge connection 278 extending from the top wall 218 of the inlet manifold 210 and a first lower sight gauge connection 280 extending from the bottom wall 220 of the inlet manifold 210. The first upper sight gauge connection 278 and the first lower sight gauge connection 280 are each in fluid communication with the inlet reservoir 238 and connect to an external level monitoring device 710 (shown in FIG. 25 ). The inlet manifold 210 also includes a second upper sight gauge connection 282 extending from the top wall 218 of the inlet manifold 210 and a second lower sight gauge connection 284 extending from the bottom wall 220 of the inlet manifold 210. The second upper sight gauge connection 282 and the second lower sight gauge connection 284 are each in fluid communication with the inlet reservoir 238 and connected to a sight gauge device 766 (shown in FIG. 26 ). The provision of the second upper sight gauge connection 282 and the second lower sight gauge connection 284 allows for monitoring of the level of binder material in the inlet reservoir 238 adjacent the opposing end walls 222, 224 of the inlet manifold 210.

[0110] In addition to the return port 300, the outlet manifold 212 of the manifold assembly 160A also includes a supply port 290 formed in the bottom wall 232 of the outlet manifold 212 and in fluid communication with the outlet reservoir 286. A supply fitting 292 is coupled to the supply port 290. The outlet manifold 212 of the manifold assembly 160A includes a first fluid level float 318, also referred to herein as a high fluid level float 318, and a second fluid level float 320, also sometimes referred to as a low fluid level float or a control fluid level float.

[0111] In an embodiment, outlet manifold 212 of manifold assembly 160A also includes a first upper sight gauge connection 322 extending from the top wall 230 of outlet manifold 212 and a first lower sight gauge connection 324 extending from the bottom wall 232 of outlet manifold 212 in fluid communication with outlet reservoir 286, for connecting to a second external level monitoring device similar to external level monitoring device 710. Outlet manifold 212 also includes a second upper sight gauge connection 326 extending from the top wall 230 of outlet manifold 212 and a second lower sight gauge connection 328 extending from the bottom wall 232 of outlet manifold 212 in fluid communication with outlet reservoir 286, for connecting to a second sight gauge device 767 similar to sight gauge device 766.

[0112] In this embodiment, the inlet manifold 210 includes a valve 330 at each of the supply port 242 and the return port 254. The valve 330 at the supply port 242 allows the flow of binder material from the supply reservoir 110 to the inlet reservoir 238, and the valve 330 at the return port 254 allows the flow of binder material from the inlet reservoir 238 to the return reservoir 112 or the supply reservoir 110. Similarly, the outlet manifold 212 also includes a valve 330 at each of the supply port 290 and the return port 300.

[0113] FIG. 13 is a flow diagram that schematically illustrates the flow of binder material through the inlet manifold 210 and outlet manifold 212 shown in FIGS. 10-12. As shown in FIG. 13, binder material flows from the supply reservoir 110 of the inlet manifold 210 via a conduit line 111, through a supply fitting 244 and a supply port 242, and into the inlet reservoir 238. A pump 250 is fluidly coupled to the conduit line 111 to pump the binder material from the supply reservoir 110 toward the inlet manifold 210. Additionally, the conduit line 111 can have a valve 252 for opening and closing a path for the binder material to flow into the inlet manifold 210. The valve 252 can be located in any suitable location, such as within the conduit line 111, adjacent to the supply reservoir 110, or adjacent to the supply port 242. Binder material flows from the inlet reservoir 238 through a return port 254 and a return fitting 256 via a conduit line 260 to the return reservoir 112 or, in embodiments, via the conduit line 260 back to the supply reservoir 110. A pump 262 is fluidly coupled to the conduit line 260 to draw binder material from the inlet reservoir 238 toward the return reservoir 112 or the supply reservoir 110. Additionally, the conduit line 260 may have a valve 264 for opening and closing a path for the binder material to flow out of the inlet manifold 210. The valve 264 may be located in any suitable location, such as within the conduit line 260, proximate to the return port 254, or proximate to the return reservoir 112. Additionally, the binder material flows from the inlet reservoir 238 through an inlet tube 270 and through a corresponding inlet port 266 toward the printhead 156.

[0114] With respect to the outlet manifold 212, binder material flows from the supply reservoir 110 via a conduit line 294, through a supply fitting 292 and a supply port 290, and into the outlet reservoir 286. A pump 250 is fluidly coupled to the conduit line 294 for pumping the binder material from the supply reservoir 110 toward the outlet manifold 212. Additionally, the conduit line 294 may have a valve 298 for opening and closing a path for the binder material to enter the outlet manifold 212. The binder material flows from the outlet reservoir 286 through a return port 300 and a return fitting 302, via the conduit line 113, to the return reservoir 112, or, in embodiments, back to the supply reservoir 110. A pump 262 is fluidly coupled to the conduit line 113 for drawing material from the outlet reservoir 286 toward the return reservoir 112 or the supply reservoir 110. Additionally, the conduit line 113 may have a valve 308 for opening or closing a path for the binder material to flow out of the outlet manifold 212. In embodiments, the inlet manifold 210 may return the binder material to the supply reservoir 110, and the outlet manifold 212 may return the binder material to the return reservoir 112, or vice versa. Additionally, unused binder material in the print head 156 flows back through the corresponding outlet port 310 via the outlet tube 314 to the outlet reservoir 286.

[0115] In practice, during a purge or unclog operation of a clogged printhead 156, the valve 330 associated with the inlet port 266 of the clogged printhead 156 is positioned in an open position, and the valve 330 associated with the outlet port 310 of the clogged printhead 156 is positioned in an open position. The valves 330 associated with the other inlet ports 266 and outlet ports 310 of the other, non-clogged printheads 156 are placed in a closed position. Thereafter, as described above, the pressure differential between the inlet manifold 210 and the outlet manifold 212 resulting from operation of the inlet vacuum 272 of the inlet manifold 210 and the outlet vacuum 316 of the outlet manifold 212 is increased from a normal pressure differential to a purge pressure differential. When the inlet vacuum 272 and the outlet vacuum 316 increase the pressure differential between the inlet manifold 210 and the outlet manifold 212 and binder material is supplied from the pressurized supply reservoir 110 into the inlet reservoir 238, the binder material is directed only through the inlet port 266 and the outlet port 310 that are in the open position, i.e., the inlet port 266 and the outlet port 310 associated with the clogged printhead 156.

[0116] In practice, when the fluid level float 274 in the inlet reservoir 238 determines that the level of fluid in the inlet reservoir 238 is above a predetermined threshold, the fluid level float 274 sends a signal to the control system 10 to allow binder material to flow out of the inlet reservoir 238 through the return port 254 of the inlet manifold 210 and into the return reservoir 112 or the supply reservoir 110. The binder material flows out of the inlet reservoir 238 in response to the opening of the valve 264, thereby allowing the binder material to flow out of the inlet reservoir 238. Additionally, when the fluid level float 274 in the inlet reservoir 238 determines that the level of binder material is below a predetermined threshold, the fluid level float 274 sends a signal to the control system 10 to allow additional binder material to flow into the inlet reservoir 238 from the supply reservoir 110 through the supply port 242. The binder material flows into the inlet reservoir 238 in response to actuation of the pump 250 , which delivers the binder material to the inlet reservoir 238 .

[0117] As mentioned above, refilling the inlet manifold 210 during a printing operation can adversely affect print quality because the pressure within the inlet manifold can fluctuate during the filling / refilling operation of the inlet manifold 210. Therefore, in embodiments, the control relay for the fluid level float 274 does not send a signal that would allow additional binder material to flow into or out of the inlet reservoir 238 while the manifold assembly 160A is actively performing a printing operation. Specifically, the control relay prevents the pumps 250, 262 from operating during a printing operation.

[0118] Additionally, if the fluid level float 318 in the outlet reservoir 286 determines that the level of fluid in the outlet reservoir 286 is above a predetermined threshold, the fluid level float 318 sends a signal to the control system 10 to allow binder material to flow out of the outlet reservoir 286 through the return port 300 of the outlet manifold 212 and into the return reservoir 112 or the supply reservoir 110. The binder material flows out of the outlet reservoir 286 in response to actuation of the pump 262, which draws binder material from the outlet reservoir 286. If the fluid level float 318 in the outlet reservoir 286 determines that the level of binder material is below a predetermined threshold, the fluid level float 318 sends a signal to the control system 10 to allow additional binder material to flow into the outlet reservoir 286 through the supply port 290 from the supply reservoir 110. In response to the opening of valve 298 at supply port 290, binder material flows into outlet reservoir 286. Direct supply of material to and from inlet manifold 210 and outlet manifold 212 allows for independent control of either or both of inlet manifold 210 and outlet manifold 212 without affecting the other of inlet manifold 210 and outlet manifold 212.

[0119] Similar to the fluid level float 274 of the inlet manifold 210, in an embodiment, the control relay of the fluid level float 318 does not send a signal to allow additional binder material to flow into or out of the outlet reservoir 286 while the manifold assembly 160A is actively performing a printing operation.

[0120] H2 Beta embodiment 14-17, another embodiment of a manifold assembly 160B is shown. It should be understood that the manifold assembly 160B is substantially similar to the manifold assemblies 160, 160A discussed herein, and thus like portions of the inlet manifold 210 and outlet manifold 212, such as the fluid level floats 274, 318, are referred to herein using like reference numerals.

[0121] In this embodiment, the inlet manifold 210 of the manifold assembly 160B includes a bypass port 400 formed in the bottom wall 220 of the inlet manifold 210 and in fluid communication with the inlet reservoir 238. A bypass fitting 402 is coupled to the bypass port 400. The outlet manifold 212 also includes a bypass port 404 formed in the bottom wall 520 of the outlet manifold 212 and in fluid communication with the outlet reservoir 286. A bypass fitting 406 is coupled to the bypass port 404. A bypass line 408 fluidly connects the inlet reservoir 238 and the outlet reservoir 286 to each other by connecting the bypass fitting 402 of the inlet manifold 210 at a first end and the bypass fitting 406 of the outlet manifold 212 at an opposite second end, as shown in FIG. 17 . Thus, binder material can flow from the inlet reservoir 238 to the outlet reservoir 286 via the bypass line 408. This allows the binder material to flow directly from the inlet reservoir 238 to the outlet reservoir 286 , bypassing the printhead 156 .

[0122] 14-17, valve 330 is not provided at supply port 242 or bypass port 400 of inlet manifold 210, or at return port 254 of outlet manifold 212. However, valve 330 is provided at bypass port 404 of outlet manifold 212. It should be understood that in other embodiments, valve 330 may be provided at bypass port 400 of inlet manifold 210, or at other ports on either inlet manifold 210 or outlet manifold 212.

[0123] 17 is a flow diagram that schematically illustrates the flow of binder material through the inlet manifold 210 and outlet manifold 212 shown in FIGS. 14-16. In practice, when the fluid level float 274 in the inlet reservoir 238 determines that the level of fluid in the inlet reservoir 238 is above a predetermined threshold, the fluid level float 274 sends a signal to the control system 10 to allow the binder material to flow out of the inlet reservoir 238, such as through a bypass port 400 in the inlet manifold 210, and into the outlet manifold 212. The binder material flows out of the inlet reservoir 238 in response to the opening of the valve 330 at the bypass port 404 in the outlet manifold 212, thereby allowing the binder material to flow out of the inlet reservoir 238. Additionally, when a fluid level float 274 located within the inlet reservoir 238 determines that the level of binder material is below a predetermined threshold, the fluid level float 274 sends a signal to the control system 10 to allow additional binder material to flow from the supply reservoir 110 through the supply port 242 into the inlet reservoir 238. The binder material flows into the inlet reservoir 238 in response to actuation of the pump 250, delivering the binder material to the inlet reservoir 238.

[0124] Additionally, when the fluid level float 318 in the outlet reservoir 286 determines that the level of fluid in the outlet reservoir 286 is above a predetermined threshold, the fluid level float 318 sends a signal to the control system 10 to allow binder material to flow out of the outlet reservoir 286, such as through the return port 300 of the outlet manifold 212, to the return reservoir 112 or the supply reservoir 110. The binder material flows out of the outlet reservoir 286 in response to actuation of the pump 262, which draws binder material from the outlet reservoir 286. When the fluid level float 318 in the outlet reservoir 286 determines that the level of binder material is below a predetermined threshold, the fluid level float 318 sends a signal to the control system 10 to allow additional binder material to flow from the inlet reservoir 238 through the bypass port 404 into the outlet reservoir 286. The binder material flows into the outlet reservoir 286 in response to the opening of the valve 330 at the bypass port 404. Utilizing the bypass ports 400, 404 in the inlet manifold 210 and outlet manifold 212, respectively, can result in faster refilling after a purge operation by allowing the binder material to flow directly from the inlet manifold 210 to the outlet manifold 212, as opposed to requiring the binder material to flow through the printhead 156.

[0125] Additionally, the inclusion of the bypass ports 400, 404 and associated valves 330 can improve the tuning process of the print assembly 150. For example, when initially tuning the print head 156, the valves 330 associated with the inlet port 266 of the inlet manifold 210 and the outlet port 310 of the outlet manifold 212 are each positioned in a closed position. In addition, the valve 330 associated with the bypass port 404 of the outlet manifold 212 is positioned in an open position. Thus, binder material flowing from the supply reservoir 110 can refill both the inlet reservoir 238 and the outlet reservoir 286 to a predetermined level. This can allow for faster filling and tuning compared to embodiments in which the bypass ports 400, 404 are not provided.

[0126] H2 Alpha embodiment 18 and 19, another embodiment of a manifold assembly 160C is shown. It should be understood that the manifold assembly 160C is substantially similar to the manifold assemblies 160, 160B discussed herein, and thus like portions of the inlet manifold 210 and outlet manifold 212 are referred to herein with like reference numerals.

[0127] 18 and 19, in this embodiment of manifold assembly 160C, inlet manifold 210 and outlet manifold 212 are integrally formed with one another. Thus, second wall 216 of inlet manifold 212 and second wall 228 of outlet manifold 212 are joined to form inner wall 522. End wall 222 of inlet manifold 210 and end wall 234 of outlet manifold 212 are joined to form integral end wall 514 of manifold assembly 160C. Similarly, end wall 224 of inlet manifold 210 and end wall 236 of outlet manifold 212 are joined to form integral opposite end wall 516 of manifold assembly 160C. Bottom wall 220 of inlet manifold 210 and bottom wall 232 of outlet manifold 212 are joined to form integral bottom wall 512 of manifold assembly 160C. Additionally, top wall 218 of inlet manifold 210 and top wall 230 of outlet manifold 212 are joined to form a unitary top wall 510 of manifold assembly 160C. As discussed in more detail herein, top wall 510 of manifold assembly 160C may be separable from and airtight to the remainder of manifold assembly 160C.

[0128] As shown in FIG. 19 , a top view of manifold assembly 160C is shown with top wall 510 removed therefrom. Inlet manifold 210 includes a groove 524 extending longitudinally between end walls 222, 224 of inlet manifold 210 along the + / -Y axes of the coordinate system shown in the figure. As shown, in the embodiment, inlet manifold 210 also includes a plurality of recesses 526 extending in inner wall 522 toward outlet manifold 212 along the + / -X axes of the coordinate system shown in the figure, and therefore perpendicular to groove 524. Groove 524 and recesses 526 of inlet manifold 210 together define inlet reservoir 238. One or more inlet ports 266 are formed in bottom wall 232 of inlet manifold 210, each located within a corresponding one of the plurality of recesses 526. In embodiments, at least some of the recesses 526 do not include a corresponding inlet port 266, while in other embodiments, each recess 526 has a corresponding inlet port 266. In embodiments, each of the inlet ports 266 is disposed along an axis B extending between the end walls 514, 516 of the manifold assembly 160C. Additionally, the supply port 242 and the bypass port 400 are formed in the bottom wall 232 of the inlet manifold 210 and in the groove 524 of the inlet manifold 210. However, in embodiments, the recess 526 is still available to receive a fluid level float 274 to determine the level of binder material in the inlet reservoir 238.

[0129] Similarly, the outlet manifold 212 includes a groove 536 extending longitudinally between the end walls 234, 236 of the outlet manifold 212 along the + / -Y axes of the coordinate system shown in the figure. In embodiments, as shown, the outlet manifold 212 also includes a plurality of recesses 538 extending in the inner wall 522 toward the inlet manifold 210 along the + / -X axes of the coordinate system shown in the figure, and therefore perpendicular to the groove 536. The groove 536 and the recesses 538 of the outlet manifold 212 together define the outlet reservoir 286. One or more outlet ports 310 are formed in the bottom wall 232 of the outlet manifold 212, each in a corresponding one of the plurality of recesses 538. In embodiments, at least some of the recesses 538 do not include a corresponding outlet port 310, although in some embodiments, each recess 538 has a corresponding outlet port 310. In an embodiment, each of the outlet ports 310 is disposed along an axis B extending between the end walls 514, 516 of the manifold assembly 160C. Thus, the inlet port 266 and the outlet port 310 are each disposed along the same axis extending between the end walls 514, 516 of the manifold assembly 160C. Additionally, the return port 300 and the bypass port 404 are formed in the bottom wall 232 of the outlet manifold 212 and in a groove 536 of the outlet manifold 212. As shown, at least one of the recesses 538 of the outlet reservoir 286 does not include an outlet port 310. However, in an embodiment, the recess 538 remains available to receive a fluid level float 318 for determining the level of binder material in the outlet reservoir 286.

[0130] As shown in FIG. 20 , a bottom view of the top wall 510 of the manifold assembly 160C is shown. The top wall 510 includes a cover 548 including a plurality of extrusions 550 extending toward the bottom wall 512 of the manifold assembly 160C for receiving at least a portion of the valve 330, as discussed in more detail above. Additionally, in embodiments, the covers 548 each include a pair of recesses 558 extending within the thickness of the top wall 510 and away from the bottom wall 512 for receiving the fluid level floats 274, 318 of the inlet manifold 210 and outlet manifold 212, respectively. In embodiments, a pair of openings 554 extend through the cover 548. If included, each opening 554 is coupled to the inlet vacuum 272 and the outlet vacuum 316, respectively, for controlling the pressure differential within the inlet reservoir 238 and the outlet reservoir 286. As shown, cover 548 may include a recess 552 for receiving a gasket 556 to form a seal between cover 548 and the other walls of manifold assembly 160C. Gasket 556 is thus configured to fit around the periphery of cover 548 and cover inner wall 522. A plurality of holes 560 are formed in each of cover 548 and gasket 556 to allow fasteners, such as screws, bolts, rivets, etc., to extend therethrough and secure cover 548 and gasket 556 to manifold assembly 160C. It should be appreciated that by allowing top wall 510 to be removed from the remainder of manifold assembly 160C, various internal components and portions of manifold assembly 160C (such as valves and floats) may be more easily accessed for repair and / or maintenance purposes, as opposed to embodiments described herein in which top wall 510 is not removable.

[0131] Manifold embodiment outside the housing While various embodiments described herein include a manifold assembly disposed within the housing of the print assembly, in some embodiments the manifold assembly is disposed outside the housing 202, on the opposite side of the rail 104 from the housing 202, as shown in Figure 21. In particular, Figures 21-23 show another embodiment of a manifold assembly 160D, which is substantially similar to the manifold assemblies 160, 160C discussed herein, and accordingly, like portions of the inlet manifold 210 and outlet manifold 212 are referred to herein using like reference numerals.

[0132] As shown, the manifold assembly 160D includes a plurality of actuators 602 for independently and selectively controlling each valve of the manifold assembly 160D. Each of the actuators 602 may be controlled by the control system 10, such as by electronic or pneumatic control. The actuators 602 may be mounted to the support bracket 152 by a frame 604 for securing the actuators 602 in position relative to the manifold assembly 160D.

[0133] As seen in Figures 22 and 23, the inlet manifold 210 and the outlet manifold 212 are fixed to one another, i.e., inseparable, and include an integral top wall 510, an integral bottom wall 512, an integral end wall 514, an opposing integral end wall 516, and an inner wall 522 that separates the inlet reservoir 238 and the outlet reservoir 286.

[0134] In this embodiment, manifold assembly 160D includes valve 600, rather than valve 330, to allow flow of binder material from inlet reservoir 238 to each printhead 156 through a corresponding inlet port 266. Valve 600 may extend through first wall 214 of inlet manifold 210 so as to be accessible from outside manifold assembly 160D. Valve 600 may be any suitable known valve for opening and closing inlet ports 266, such as, for example, a spool valve, a rotatable flapper, a plunger, or the like.

[0135] In embodiments, the valves 600 may be configured to simultaneously open and close the corresponding inlet ports 266 and the corresponding outlet ports 310. However, it is contemplated that embodiments may have separate valves 600 for selectively and independently opening and closing the inlet ports 266 and the outlet ports 310 to enable the flow of binder material through the inlet manifold 210 and the outlet manifold 212, respectively. Additionally or alternatively, a valve 600 may be provided at each of the supply port 242 of the inlet manifold 210 and the return port 300 of the outlet manifold 212 to enable the flow of binder material from the supply reservoir 110 to the return reservoir 112, respectively.

[0136] As shown, the externally accessible end of the valve 600 of the manifold assembly 160D is rotatable by an associated actuator 602 to operate the valve 600 between an open position and a closed position. In the open position, binder material can flow through the corresponding inlet port 266. In the closed position, binder material is prevented from flowing through the corresponding inlet port 266.

[0137] In practice, the valves 600 associated with the inlet port 266 and outlet port 310 of the clogged printhead 156 may be positioned in an open position by the associated actuators 602, while the other valves 600 are positioned in a closed position to focus pressure from the supply reservoir 110 onto the clogged printhead 156. The pressure differential between the inlet manifold 210 and the outlet manifold 212 resulting from the operation of the inlet vacuum 272 of the inlet manifold 210 and the outlet vacuum 316 of the outlet manifold 212 is then increased from a normal pressure differential to a purge pressure differential.

[0138] It should be understood that the methods for filling and adjusting a manifold assembly described above may be implemented with manifold assembly 160D to enable rapid refilling of both inlet reservoir 238 and outlet reservoir 286 to a predetermined level. Although not shown in the embodiment, it is further contemplated that a bypass line, such as bypass line 408 in manifold assembly 160B, may extend between inlet manifold 210 and outlet manifold 212 to enable binder material to flow from inlet reservoir 238 to outlet reservoir 286, bypassing printhead 156. Accordingly, manifold assembly 160D may include valve 600 in bypass port 400 of inlet manifold 210 to open or close a path through the bypass line. Additionally, other features described with respect to other embodiments of the manifold assembly may be included in manifold assembly 160D (or other manifold assemblies described herein), and features described with respect to manifold assembly 160D may be included in other manifold assembly embodiments. The above-mentioned features that may be included in any one or more of the manifold assemblies described herein include, for example, various floats, gauges, and sensors.

[0139] Floats / Gauges / Sensors 24, the first fluid level float 274 and the second fluid level float 276 described above with respect to Figures 10-13 are shown and discussed in more detail. While the fluid level floats 274, 276 are illustrated with the inlet manifold 210 of the manifold assembly 160, it should be understood that the present disclosure is applicable to the inlet manifold 210 and outlet manifold 212 of any of the manifold assemblies of the invention herein.

[0140] In embodiments, the first fluid level float 274 is configured to sense the level of binder material in the inlet reservoir 238 and send a signal to the control system 10 to take action (e.g., including initiating an alarm function) when the level of binder material in the inlet reservoir 238 exceeds a predetermined threshold. Similarly, the second fluid level float 276 is configured to sense the level of binder material in the inlet reservoir 238 and send a signal to the control system 10 to take action (e.g., including initiating an alarm function) when the level of binder material in the inlet reservoir 238 falls below a predetermined threshold. In some embodiments, the first fluid level float 274 and the second fluid level float 276 are analog floats configured to continuously monitor the level of binder material. The provision of the first fluid level float 274 and the second fluid level float 276 allows for the detection of additional levels of binder material in the inlet reservoir 238 compared to the level of binder material detected by utilizing only a single fluid level float. Additionally, the first fluid level float 274 may be configured to detect when a high level of binder material is present in the inlet reservoir 238, while the second fluid level float 276 may be configured to compare data with the first fluid level float 274.

[0141] As a non-limiting example, when a first fluid level float 274 in the inlet reservoir 238 determines that the level of fluid in the inlet reservoir 238 is above a predetermined threshold, the first fluid level float 274 sends a signal to the control system 10 to allow binder material, if provided, to flow out of the inlet reservoir 238 through either the return port 254 or the bypass port 400 of the inlet manifold 210. As another non-limiting example, when a second fluid level float 276 provided in the inlet reservoir 238 determines that the level of binder material is below a predetermined threshold, the second fluid level float 276 sends a signal to the control system 10 to allow additional binder material to flow into the inlet reservoir 238 through the supply port 242 of the inlet manifold 210.

[0142] 25, external level monitoring device 710 includes first upper sight gauge connection 278 and first lower sight gauge connection 280. Although external level monitoring device 710 in FIG. 25 is shown in combination with inlet manifold 210 of manifold assembly 160A, it is contemplated that external level monitoring device 710 may be used in combination with inlet manifold 210 or outlet manifold 212 of any manifold assembly discussed herein.

[0143] The external level monitoring device 710 includes an elongated groove 712 having a first end 714 and an opposite second end 716, a first connection 718 proximate the first end 714 of the elongated groove 712, a second connection 720, and a third connection 722 proximate the second end 716 of the elongated groove 712. A first conduit 758 is coupled to the first connection 718 of the external level monitoring device 710 and fluidly connects the external level monitoring device 710 to the inlet reservoir 238 via the first lower sight gauge connection 280 of the inlet manifold 210. A second conduit 760 is coupled to the second connection 720 of the external level monitoring device 710 to provide a vacuum path 762 from the second connection 720 of the external level monitoring device 710 to its third connection 722. The second conduit 760 can be in fluid communication with the inlet reservoir 238 via the first upper sight gauge connection 278 of the inlet manifold 210. A vacuum connection 764 is coupled to the third connection 722 at the second end 732 of the external level monitoring device 710.

[0144] Portions of the elongated groove 712, such as the first portion 724 between the first connection 718 and the second connection 720, and the second portion 726 between the second connection 720 and the third connection 722, may be at least partially transparent to allow visual monitoring of the level of binder material within the external level monitoring device 710, as discussed in more detail herein.

[0145] The first stop 728 is disposed within the elongated groove 712 between the first connecting portion 718 and the second connecting portion 720. The first stop 728 faces the first connecting portion 718 and includes a first end 730 having a contoured surface. In embodiments, the contoured surface may be tapered or spherical. In embodiments, the first stop 728 includes a second end 732 having a flange 734 configured to engage the elongated groove 712 and secure the first stop 728 within the external level monitoring device 710. In other embodiments, the first stop 728 may be secured within the elongated groove 712 using any other suitable fastening means. A first floating member 736, such as a ball, is disposed within the elongated groove 712 between the first connecting portion 718 and the first stop 728.

[0146] The second stop 738 is positioned within the elongated groove 712 between the second connecting portion 720 and the third connecting portion 722, adjacent the second connecting portion 720. In embodiments, the second stop 738 has a first end 740 facing the second connecting portion 720, the first end including a flange 742 configured to engage the elongated groove 712 and secure the second stop 738 within the external level monitoring device 710. In other embodiments, the second stop 738 may be secured within the elongated groove 712 using any other suitable fastening means. The second stop 738 has an opposite second end 744 facing the third connecting portion 722 that includes a partially contoured surface. In embodiments, the contoured surface is tapered or spherical. The second stop 738 also includes at least one notch 746 extending from the second end 744 toward the first end 740. In an embodiment, second stop 738 includes a pair of diametrically opposed notches 746 each extending partially from second end 744 of second stop 738 toward first end 740 of second stop 738 .

[0147] The third stop 748 is positioned proximate the third connecting portion 722 within the elongated groove 712 between the second connecting portion 720 and the third connecting portion 722 and includes a structure similar to the first stop 728. The third stop 748 is positioned within the elongated groove 712 such that a first end 750 of the third stop 748, which has a contoured surface, faces the second connecting portion 720. In embodiments, the contoured surface of the first end 750 of the third stop 748 is tapered or spherical. In embodiments, the third stop 748 includes an opposite second end 752 that faces the third connecting portion 722 and has a flange 754 configured to engage the elongated groove 712 to secure the third stop 748 within the external level monitoring device 710. In other embodiments, the third stop 748 may be secured within the elongated groove 712 using any other suitable fastening means. A second floating member 756 , such as a ball, is disposed within the elongated groove 712 between the second stop 738 and the third stop 748 .

[0148] As binder material flows from the inlet manifold 210 through the first conduit 758 into the external level monitoring device 710, the first floating member 736 is raised by the binder material entering the external level monitoring device 710. The first floating member 736 is raised until it contacts and engages the contoured first end 730 of the first stop 728, forming a seal. As air flows through the second connection 720 via the second conduit 760 toward the third connection 722, the second floating member 756 moves from the second stop 738 to the third stop 748. Initially, when there is no or limited air flow through the second connection, the second floating member 756 is positioned against the second stop 738. Air is allowed to flow through the notch 746 and around the second end 744 of the second stop 738 to allow airflow toward the third connection 722 of the external level monitoring device 710. When the second floating member 756 is pushed away from the second stop 738 and toward the third stop 748, the second floating member 756 engages the first end 750 of the third stop 748 to create a seal that prevents air from flowing through the vacuum connection 764 at the third connection 722 of the external level monitoring device 710.

[0149] 26, at least one sight gauge 766 is shown in combination with a manifold assembly 160A that includes a second upper sight gauge connection 282 and a second lower sight gauge connection 284. As shown, a pair of sight gauges 766, 767 are provided that can be in fluid communication with the inlet manifold 210 and the outlet manifold 212, respectively, for monitoring the level of binder material therein. Each sight gauge 766, 767 includes similar structure, and therefore, only the sight gauge 766 in fluid communication with the inlet manifold 210 will be described in greater detail herein.

[0150] The sight gauge 766 includes a tube 768 formed of a transparent binder material having a first end 770 in fluid communication with the inlet reservoir 238 via the second lower sight gauge connection 284 of the inlet manifold 210. In an embodiment, the tube 768 has a second end 774 in fluid communication with the inlet reservoir 238 via the second upper sight gauge connection 282 of the inlet manifold 210 to ensure that the binder material in the tube 768 is returned to the inlet manifold 210. The sight gauge 766 includes a holder 778 securable to the tube 768 to secure the tube 768 in a predetermined position relative to the manifold assembly 160. In an embodiment, the holder 778 includes a receiver 780 having a see-through portion 782, such as an opening or otherwise transparent portion, extending longitudinally along the receiver 780 for observing the level of binder material in the tube 768. The receiver 780 is configured to receive the tube 768 and secure the holder 778 to the tube 768. Thus, in embodiments in which the tube 768 is cylindrical, the receiving portion 780 of the holder 778 has a cylindrical cross-section for receiving the tube 768. The holder 778 also includes indicia 784, such as a series of notches, lines, numbers, etc., along at least one side of the see-through portion, each of which corresponds to a level of binder material within the tube 768 and, therefore, within the inlet manifold 210. For example, the indicia 784 may include lines with corresponding numbers indicating the level of binder material as seen within the tube 768 through the see-through portion 782 of the holder 778. In embodiments, the holder 778 also includes a clamp 786 for coupling the holder 778 to a portion of the manifold assembly 160A itself. As shown, the clamp 786 includes opposing fingers 788 dimensioned to secure the holder 778 to the manifold assembly 160A. Thus, the clamp 786 of the holder 778 also secures the tube 768 in place relative to the manifold assembly 160A. However, other types of clamps may be used depending on the particular embodiment.

[0151] From the above, it should be understood that what is defined herein is a print assembly including a manifold assembly having an inlet manifold and an outlet manifold detachable from the inlet manifold. The inlet manifold includes an inlet reservoir and an inlet port. The outlet manifold includes an outlet reservoir and an outlet port. The manifold assembly includes an inlet valve at the inlet port of the inlet reservoir and an outlet valve at the outlet port of the outlet reservoir. The print assembly includes a printhead in fluid communication with both the inlet reservoir of the inlet manifold via the inlet port and the outlet reservoir of the outlet manifold via the outlet port. The inlet valve and outlet valve are independently operable to allow flow of binder material from the inlet reservoir to the printhead and from the printhead to the outlet reservoir, respectively. By allowing independent control of the inlet and outlet manifolds, control of binder material to and from the printhead can be better managed during use and maintenance.

[0152] Further aspects of the present invention are provided by the subject matter of the following appendices.

[0153] Appendix 1. an inlet manifold including an inlet reservoir and a plurality of inlet ports; an outlet manifold including an outlet reservoir and a plurality of outlet ports; a plurality of inlet valves in the inlet manifold; a plurality of outlet valves in the outlet manifold; a manifold assembly including: Housing and a plurality of printheads disposed within the housing; a printing head including: Including, each of the plurality of printheads in fluid communication with the inlet reservoir through a corresponding one of the plurality of inlet ports and in fluid communication with the outlet reservoir through a corresponding one of the plurality of outlet ports; each of the plurality of inlet valves and the plurality of outlet valves is independently operable to allow or prevent flow of binder material from the inlet reservoir to a corresponding one of the plurality of printheads and from the corresponding one of the plurality of printheads to the outlet reservoir, respectively; Print assembly.

[0154] Appendix 2. the manifold assembly is disposed within the housing of the printing head; 10. The print assembly of claim 1.

[0155] Appendix 3. a plurality of inlet tubes, each of the plurality of inlet tubes coupling a corresponding one of the plurality of printheads to a corresponding one of the plurality of inlet ports; a plurality of outlet tubes, each of the plurality of outlet tubes coupling a corresponding one of the plurality of printheads to a corresponding one of the plurality of outlet ports; 3. The print assembly of claim 1 or claim 2, further comprising:

[0156] Appendix 4. a plurality of inlet fittings, each of the plurality of inlet fittings coupled to a corresponding one of the plurality of inlet ports, the plurality of inlet fittings being arranged in alternating angular orientations; a plurality of outlet fittings, each of the plurality of outlet fittings coupled to a corresponding one of the plurality of outlet ports, the plurality of outlet fittings being arranged in alternating angular orientations; 4. The print assembly of claim 1, further comprising:

[0157] Appendix 5. the inlet manifold is separable from the outlet manifold; A print assembly according to any one of Supplementary Notes 1 to 4.

[0158] Appendix 6. further comprising a plurality of actuators; each of the plurality of actuators is directly coupled to a corresponding one of the plurality of inlet valves or a corresponding one of the plurality of outlet valves to move the corresponding valve between an open position and a closed position; 7. A print assembly according to any one of claims 1 to 6.

[0159] Appendix 7. a first bypass port through the inlet manifold; a second bypass port through the outlet manifold; a bypass line fluidly connecting the first bypass port to the second bypass port to allow binder material to flow from the inlet reservoir to the outlet reservoir without passing through any one of the plurality of printheads; 7. The print assembly according to any one of claims 1 to 6, comprising:

[0160] Appendix 8. At least one of the first and second bypass ports is coupled to a corresponding bypass valve operable between an open position that allows binder material to flow from the inlet reservoir into the outlet reservoir and a closed position that prevents binder material from flowing from the inlet reservoir into the outlet reservoir. A print assembly according to any one of Supplementary Notes 1 to 7.

[0161] Appendix 9. Each of the plurality of inlet valves and the plurality of outlet valves comprises: A receptacle; a plunger received within the receptacle; Including, The plunger is movable between a raised position when the corresponding valve is in the open position and a lowered position when the corresponding valve is in the closed position. A print assembly according to any one of Supplementary Notes 1 to 8.

[0162] Appendix 10. the plunger includes a seal at an end of the plunger opposite the receptacle for providing an airtight seal between the plunger and an associated port when the plunger is in the lowered position; A print assembly according to any one of Supplementary Notes 1 to 9.

[0163] Appendix 11. each of the plurality of inlet valves and the plurality of outlet valves includes a proximity sensor within the receptacle to detect whether the plunger is in the open position or the closed position; 11. A print assembly according to any one of claims 1 to 10.

[0164] Appendix 12. each of the plurality of inlet valves and the plurality of outlet valves includes a pneumatic actuator for switching between the open and closed positions; 12. A print assembly according to any one of claims 1 to 11.

[0165] Appendix 13. each of the valves includes an electric actuator for switching between the open and closed positions; 13. A print assembly according to any one of claims 1 to 12.

[0166] Appendix 14. further comprising a fluid level float in at least one of the inlet manifold and the outlet manifold for sensing a level of material; 14. A print assembly according to any one of claims 1 to 13.

[0167] Appendix 15. the fluid level float is configured to detect a level of binder material within the manifold assembly; the fluid level float is configured to send a signal to a control system to perform an alarm function if the level of the binder material exceeds a predetermined threshold. 15. A print assembly according to any one of claims 1 to 14.

[0168] Appendix 16. the fluid level float is an analog float configured to continuously monitor the level of binder material; 16. A print assembly according to any one of claims 1 to 15.

[0169] Appendix 17. the inlet manifold and the outlet manifold each include a first fluid level float and a second fluid level float; the first fluid level float is configured to detect when the binder material exceeds a predetermined low threshold; the second fluid level float is configured to detect when the binder material exceeds a predetermined high threshold. 17. A print assembly according to any one of claims 1 to 16.

[0170] Appendix 18. further comprising a fluid level monitoring device that allows for visual monitoring of the level of binder material in at least one of the inlet manifold and the outlet manifold. 18. A print assembly according to any one of claims 1 to 17.

[0171] Appendix 19. further comprising a retainer bracket configured to secure the inlet manifold and the outlet manifold relative to the print head. 19. A print assembly according to any one of claims 1 to 18.

[0172] Appendix 20. at least one of the plurality of inlet valves and the plurality of outlet valves includes a camshaft including at least one lobe; rotation of the camshaft moves the lobe to open or close a corresponding one of the plurality of inlet ports or the plurality of outlet ports; 19. A print assembly according to any one of claims 1 to 19.

[0173] Appendix 21. The camshaft is coupled to a rotary actuator. 21. A print assembly according to any one of claims 1 to 20.

[0174] Appendix 22. the camshaft having a plurality of lobes associated with a corresponding one of the plurality of inlet ports or the plurality of outlet ports such that a corresponding one of the plurality of inlet ports or the plurality of outlet ports may be opened and closed multiple times during a single complete rotation of the camshaft. 22. A print assembly according to any one of claims 1 to 21.

[0175] Appendix 23. a vacuum disposed within at least one of the inlet manifold and the outlet manifold; the at least one vacuum establishes a pressure differential between the inlet manifold and the outlet manifold; 23. A print assembly according to any one of claims 1 to 22.

[0176] Appendix 24. During normal operation, the pressure differential ranges from -1.0 psi to 0.0 psi, The pressure difference during the purge operation ranges from 0.7 psi to 2 psi. 24. A print assembly according to any one of claims 1 to 23.

[0177] Appendix 25. the print assembly is mounted on a traverse stage that sets an index of the print assembly; 25. A print assembly according to any one of claims 1 to 24.

[0178] Appendix 26. A print assembly according to any one of claims 1 to 25; at least one binder reservoir that provides binder material directly to at least one of the inlet manifold and the outlet manifold and receives binder material from at least one of the inlet manifold and the outlet manifold; 2. A manufacturing device comprising:

[0179] Appendix 27. 1. A method for clearing a printhead clog in a printing head assembly, comprising: an inlet manifold for delivering binder material to a plurality of print heads, each of the plurality of print heads being coupled to the inlet manifold through a corresponding one of a plurality of inlet ports, and one of a plurality of inlet valves being provided for each of the plurality of inlet ports; an outlet manifold for receiving unused binder material from the plurality of printheads, each of the plurality of printheads being coupled to the outlet manifold through a corresponding one of a plurality of outlet ports, and one of a plurality of outlet valves being provided in each of the plurality of outlet ports; a manifold assembly having: the inlet manifold has a first pressure; the outlet manifold has a second pressure; a pressure differential exists between the inlet manifold and the outlet manifold; closing, by a control unit, at least one of the plurality of inlet valves to prevent binder material from flowing from the inlet manifold to the corresponding printhead while at least another of the plurality of inlet valves is in an open position; applying a positive pressure effective to adjust the pressure differential between the inlet manifold and the outlet manifold to allow binder material to flow only through the inlet port with the associated inlet valve in the open position, thereby clearing a clog in the associated printhead; method.

[0180] Appendix 28. Open at least one closed inlet valve, Close at least one open inlet valve; applying a positive pressure effective to unclog a different one of the plurality of printheads; 28. The method of claim 27, further comprising:

[0181] Appendix 29. the positive pressure is in the range of 0.7 psi to 2 psi; Normal operating pressure ranges from -1.0 psi to 0.0 psi, The positive pressure is based on the number of inlet valves that are open. 29. The method of claim 27 or 28.

[0182] Appendix 30. further comprising closing all but one of the plurality of inlet valves such that only one of the plurality of inlet valves is open. A method according to any one of appendices 27 to 29.

[0183] Appendix 31. and operating a pump in a binder reservoir to direct binder material to the inlet manifold and the inlet valve in the open position to clear a clog in an associated printhead through a corresponding one of the plurality of inlet ports. A method according to any one of appendices 27 to 30.

[0184] Appendix 32. the inlet manifold includes a first bypass port; the outlet manifold includes a second bypass port; a bypass valve associated with one of the first bypass port and the second bypass port; closing each of the plurality of inlet valves and the plurality of outlet valves; Open the bypass valve; applying a vacuum to remove air from the manifold assembly; A method according to any one of Supplementary Notes 27 to 31.

[0185] Appendix 33. 1. A method for circulating binder material through a print assembly, comprising: an inlet manifold including an inlet reservoir and a plurality of inlet ports; an outlet manifold including an outlet reservoir and a plurality of outlet ports; a plurality of inlet valves in the inlet manifold; a plurality of outlet valves in the outlet manifold; a manifold assembly including: each of the plurality of inlet valves and the plurality of outlet valves is independently operable; delivering a binder material from at least one binder reservoir to the inlet manifold or the outlet manifold; receiving a binder material from the inlet manifold or the outlet manifold into the at least one binder reservoir; applying a pressure differential across the inlet manifold and the outlet manifold; the pressure differential is controllable based on operation of each of the plurality of inlet valves and the plurality of outlet valves. method.

[0186] Appendix 34. determining whether a level of binder material in at least one of the inlet manifold and the outlet manifold is above or below a predetermined threshold; 34. The method of claim 33, further comprising:

[0187] Appendix 35. determining that a level of binder material in the inlet manifold is above a predetermined threshold; In response to the determining, reducing a velocity of binder material being dispensed from the at least one reservoir into the inlet manifold, increasing a velocity of binder material being withdrawn from the inlet manifold toward the at least one reservoir, or both. 35. The method of any of Clauses 33 or 34, further comprising:

[0188] Appendix 36. determining that the level of binder material in the inlet manifold is below a predetermined threshold; In response to said determining, increasing a velocity of binder material being dispensed from said at least one reservoir into said inlet manifold, decreasing a velocity of binder material being withdrawn from said inlet manifold towards a return reservoir, or both. 36. The method of any one of appendices 33 to 35, further comprising:

[0189] Appendix 37. providing a fluid level float within said inlet manifold; determining that a level of binder material in the inlet manifold is above a predetermined threshold; increasing an output rate of binder material from the outlet manifold to the at least one binder reservoir; 37. The method of any one of appendices 33 to 36, further comprising:

[0190] Appendix 38. providing a fluid level float within said inlet manifold; determining that the level of binder material in the inlet manifold is below a predetermined threshold; reducing an output rate of binder material from the outlet manifold to the at least one binder reservoir; 38. The method of any one of appendices 33 to 37, further comprising:

[0191] Appendix 39. 1. A method for adjusting a printing head assembly including a plurality of printheads, comprising: an inlet manifold that delivers binder material to the plurality of printheads, each of the plurality of printheads being coupled to the inlet manifold through a corresponding one of a plurality of inlet ports, and one of a plurality of inlet valves being provided for each of the plurality of inlet ports; an outlet manifold that receives unused binder material from each of the plurality of printheads, each of the plurality of printheads being coupled to the outlet manifold through a corresponding one of a plurality of outlet ports, and one of a plurality of outlet valves being provided for each of the plurality of outlet ports; a manifold assembly including: the inlet manifold has a first pressure; the outlet manifold has a second pressure; closing, by a control unit, all of the plurality of inlet valves and the plurality of outlet valves to prevent binder material from flowing from the inlet manifold to the corresponding printhead and from the corresponding printhead to the outlet manifold; opening a bypass valve to allow binder material to flow from the inlet manifold to the outlet manifold; Varying at least one of the first pressure and the second pressure to establish a pressure differential between the inlet manifold and the outlet manifold. method.

[0192] Appendix 40. said pressure differential during normal operation being in the range of −1.0 psi to 0.0 psi; The pressure differential during the purge operation is in the range of 0.7 psi to 2 psi. 39. The method described in Appendix 39.

[0193] Appendix 41. varying at least one of the first pressure and the second pressure includes providing binder material from the inlet manifold to the outlet manifold through the bypass valve. 41. The method of claim 39 or 40.

[0194] Appendix 42. varying at least one of the first pressure and the second pressure includes applying a vacuum to at least one of the inlet manifold and the outlet manifold. A method according to any one of appendices 39 to 41.

[0195] Appendix 43. varying at least one of the first pressure and the second pressure includes supplying a binder material from a supply reservoir to at least one of the inlet manifold and the outlet manifold; 40. The method of claim 39.

[0196] While particular embodiments have been illustrated and described herein, it should be understood that various other changes and modifications can be made without departing from the scope of the claimed subject matter. In particular, features of each print assembly or manifold assembly may be interchangeable between embodiments without departing from the scope of the claimed subject matter. Moreover, although various aspects of the claimed subject matter have been described herein, such aspects need not be utilized in combination. Furthermore, although not shown herein, it should be understood that it is contemplated that a print assembly may include two or more manifold assemblies, such that each manifold assembly may be in fluid communication with all or a subset of the printheads. Therefore, it is intended that the appended claims cover all such changes and modifications that are within the scope of the claimed subject matter.

[0197] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of co-pending U.S. Provisional Patent Application No. 63 / 093,852, filed October 20, 2020, entitled "Printing Assemblies and Methods for Using the Same," which is incorporated herein by reference in its entirety, including any drawings.

Claims

1. 1. A printing assembly adjustment method for adjusting a printing head assembly including a plurality of printheads, comprising: an inlet manifold that delivers binder material to the plurality of printheads, each of the plurality of printheads being coupled to the inlet manifold through a corresponding one of a plurality of inlet ports, and one of a plurality of inlet valves being provided for each of the plurality of inlet ports; an outlet manifold that receives unused binder material from the plurality of printheads, each of the plurality of printheads being coupled to the outlet manifold through a corresponding one of a plurality of outlet ports, and one of a plurality of outlet valves being provided in each of the plurality of outlet ports; a manifold assembly including: the inlet manifold has a first pressure; the outlet manifold has a second pressure; closing, by a control unit, all of the plurality of inlet valves and the plurality of outlet valves to prevent binder material from flowing from the inlet manifold to the corresponding printhead and from the corresponding printhead to the outlet manifold; opening a bypass valve to allow binder material to flow from the inlet manifold to the outlet manifold; Varying at least one of the first pressure and the second pressure to establish a pressure differential between the inlet manifold and the outlet manifold; detecting a level of binder material in at least one of the inlet manifold and the outlet manifold with a fluid level float; sending a signal to a control system that performs an alarm function when it is determined that the level of detected binder material exceeds a predetermined threshold; How to adjust the printing head assembly.

2. reducing a rate at which binder material is being provided from a supply reservoir to the inlet manifold, or increasing a rate at which binder material is being withdrawn from the inlet manifold toward the supply reservoir, or both, when it is determined that the detected level of binder material exceeds the predetermined threshold. further comprising:

2. The method for adjusting a printing head assembly according to claim 1.

3. and, if it is determined that the detected level of binder material exceeds the predetermined threshold, responsive to said determination, increasing a rate at which binder material is being provided from said at least one reservoir to said inlet manifold, decreasing a rate at which binder material is being withdrawn from said inlet manifold towards a return reservoir, or both. further comprising:

2. The method for adjusting a printing head assembly according to claim 1.

4. 1. A printing assembly adjustment method for adjusting a printing head assembly including a plurality of printheads, comprising: an inlet manifold that delivers binder material to the plurality of printheads, each of the plurality of printheads being coupled to the inlet manifold through a corresponding one of a plurality of inlet ports, and one of a plurality of inlet valves being provided for each of the plurality of inlet ports; an outlet manifold that receives unused binder material from the plurality of printheads, each of the plurality of printheads being coupled to the outlet manifold through a corresponding one of a plurality of outlet ports, and one of a plurality of outlet valves being provided in each of the plurality of outlet ports; a manifold assembly including: the inlet manifold has a first pressure; the outlet manifold has a second pressure; closing, by a control unit, all of the plurality of inlet valves and the plurality of outlet valves to prevent binder material from flowing from the inlet manifold to the corresponding printhead and from the corresponding printhead to the outlet manifold; opening a bypass valve to allow binder material to flow from the inlet manifold to the outlet manifold; Varying at least one of the first pressure and the second pressure to establish a pressure differential between the inlet manifold and the outlet manifold; The manifold assembly includes: a plurality of inlet fittings, each of the plurality of inlet fittings coupled to a corresponding one of the plurality of inlet ports, the plurality of inlet fittings being arranged in alternating angular orientations; a plurality of outlet fittings, each of the plurality of outlet fittings coupled to a corresponding one of the plurality of outlet ports, the plurality of outlet fittings being arranged in alternating angular orientations; further comprising: How to adjust the printing head assembly.

5. 1. A printing assembly adjustment method for adjusting a printing head assembly including a plurality of printheads, comprising: an inlet manifold that delivers binder material to the plurality of printheads, each of the plurality of printheads being coupled to the inlet manifold through a corresponding one of a plurality of inlet ports, and one of a plurality of inlet valves being provided for each of the plurality of inlet ports; an outlet manifold that receives unused binder material from the plurality of printheads, each of the plurality of printheads being coupled to the outlet manifold through a corresponding one of a plurality of outlet ports, and one of a plurality of outlet valves being provided in each of the plurality of outlet ports; a manifold assembly including: the inlet manifold has a first pressure; the outlet manifold has a second pressure; closing, by a control unit, all of the plurality of inlet valves and the plurality of outlet valves to prevent binder material from flowing from the inlet manifold to the corresponding printhead and from the corresponding printhead to the outlet manifold; opening a bypass valve to allow binder material to flow from the inlet manifold to the outlet manifold; Varying at least one of the first pressure and the second pressure to establish a pressure differential between the inlet manifold and the outlet manifold; the inlet manifold is separable from the outlet manifold; How to adjust the printing head assembly.

6. 1. A printing assembly adjustment method for adjusting a printing head assembly including a plurality of printheads, comprising: an inlet manifold that delivers binder material to the plurality of printheads, each of the plurality of printheads being coupled to the inlet manifold through a corresponding one of a plurality of inlet ports, and one of a plurality of inlet valves being provided for each of the plurality of inlet ports; an outlet manifold that receives unused binder material from the plurality of printheads, each of the plurality of printheads being coupled to the outlet manifold through a corresponding one of a plurality of outlet ports, and one of a plurality of outlet valves being provided in each of the plurality of outlet ports; a manifold assembly including: the inlet manifold has a first pressure; the outlet manifold has a second pressure; closing, by a control unit, all of the plurality of inlet valves and the plurality of outlet valves to prevent binder material from flowing from the inlet manifold to the corresponding printhead and from the corresponding printhead to the outlet manifold; opening a bypass valve to allow binder material to flow from the inlet manifold to the outlet manifold; Varying at least one of the first pressure and the second pressure to establish a pressure differential between the inlet manifold and the outlet manifold; the inlet manifold and the outlet manifold each include a first fluid level float and a second fluid level float; the first fluid level float is configured to detect when the binder material exceeds a predetermined low threshold; the second fluid level float is configured to detect when the binder material exceeds a predetermined high threshold. How to adjust the printing head assembly.

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