THREE-DIMENSIONAL PRINTER NOZZLE AND ASSEMBLY

The present disclosure relates to a nozzle for a three-dimensional printer. The nozzle comprises a body comprising an inlet, an outlet, and a flow path connecting the inlet and the outlet. The body comprises a leading side and a trailing side opposite the leading side. A tab positioned adjacent to the outlet extends outwardly relative to the trailing side of the body.

FIELD

The present disclosure relates to three-dimensional printing. More particular, this disclosure is directed to a nozzle and assembly for three-dimensional printing.

BACKGROUND

A building structure (e.g., building, dwelling, shed, home, etc.) may be constructed with a multitude of different materials and construction methods. Among the materials commonly used in the construction of a building structure is concrete or cement. For example, cementitious material may be mixed with water and other dry ingredients to form the foundation and the interior or exterior walls of the building.

Conventional systems and apparatus for construction of buildings, walls, and other structures for extruding or printing cementitious materials are problematic or lacking altogether. Extruding cementitious materials in the context of construction of structures is typically difficult and unable to print structures that are able to cure, dry, retain or achieve shapes of high design quality, and maintain structural integrity and strength are some of the problems not solved by conventional techniques for the use of cement in construction. Thus, a solution for printing cementitious materials is required without the limitations of conventional techniques.

SUMMARY

The present disclosure relates to a three-dimensional printer nozzle and method for three-dimensional printing. In accordance with some examples, a nozzle for a three-dimensional printer may include a body comprising an inlet, an outlet, and a flow path connecting the inlet and the outlet. The body may include a leading side and a trailing side disposed opposite the leading side. A tab may be positioned adjacent to the outlet and may extend outwardly relative to the trailing side of the body.

In accordance with some examples, three-dimensional printing may include dispensing a solidifiable material through a nozzle comprising an inlet, an outlet, and a flow path extending between the inlet and the outlet. For example, three-dimensional printing may include depositing solidifiable material onto a printing surface, forming a deposited solidifiable material. Three-dimensional printing may further include shaping deposited solidifiable material using a tab that extends outwardly from the outlet of the nozzle.

In accordance with other examples, a nozzle assembly for a three-dimensional printer may include a body comprising an inlet, an outlet, and a flow path connecting the inlet and the outlet. The body may include a leading side and a trailing side opposite the leading side. A tab may be positioned adjacent to the outlet and movable relative to the outlet of the body.

In accordance with another example, three-dimensional printing may include dispensing a solidifiable material through a nozzle of a nozzle assembly, the nozzle having an inlet, an outlet, and a flow path extending between the inlet and the outlet. The method may include depositing solidifiable material onto a printing surface, forming a deposited solidifiable material. Further, three-dimensional printing may include shaping deposited solidifiable material using a tab that is movable relative to the outlet of the nozzle.

In still other examples, a three-dimensional printer nozzle, a nozzle assembly for a three-dimensional printer, and/or a method of three-dimensional printing may further include any one or more of the following aspects. In some examples, a cross-sectional shape of the flow path at the outlet may include a leading edge defining a first length and a trailing edge defining a second length greater than the first length.

In another example, a three-dimensional printer flow path of cementitious material may have a polygonal cross-sectional shape at an outlet of a printer nozzle or nozzle assembly.

In other examples, a leading side of a body of a three-dimensional printer may have an interior wall partially defining a flow path for cementitious material extruded from a three dimensional printer, printer nozzle, or printer nozzle assembly.

In some examples, an interior wall of a leading side of a nozzle or nozzle assembly of a three-dimensional printer may have a sloped interior surface.

In some examples, an interior wall of a leading side of a nozzle or nozzle assembly of a three-dimensional printer may be non-parallel to an interior wall of the trailing side.

In another example, an interior wall of a nozzle or nozzle assembly of a three-dimensional printer of a trailing side may have a sloped interior surface.

In another example, a nozzle or nozzle assembly of a three-dimensional printer may have a tab configured to extend both laterally and longitudinally relative to an outlet end of the nozzle. In other examples, a tab may be integrated with the body. In some examples, a tab may extend laterally outward relative to one or more of the leading side and a different side of the body.

In some examples, a nozzle or nozzle assembly of a three-dimensional printer may have a flow path of printed material (i.e., printed cementitious material) that has a cross-sectional area configured to transition from circular to polygonal in a direction toward the outlet.

In another example, a nozzle or nozzle assembly of a three-dimensional printer has a tab that may include a first height adjacent to a body of the nozzle and a second height greater than the first height and spaced from the body.

In other examples, three-dimensional printing may include shaping solidifiable material against a sloped surface of an interior wall of a nozzle or nozzle assembly of a three-dimensional printer.

In some examples, shaping solidifiable material may include passing or extruding solidifiable material along a flow path having a circular cross-sectional area at an inlet of a nozzle or nozzle assembly of a three-dimensional printer, and a polygonal cross-sectional area at an outlet of the nozzle or nozzle assembly of a three-dimensional printer.

In another example, shaping solidifiable material may include passing, printing, or extruding the solidifiable material through an outlet of a nozzle or nozzle assembly of a three-dimensional printer having a trapezoidal shape.

In another example, shaping the solidifiable material may include engaging a sloped surface of an interior wall of a nozzle or nozzle assembly of a three-dimensional printer with the solidifiable material such that the nozzle or nozzle assembly applies a compressive force to the solidifiable material in a direction opposite the direction of travel.

In other examples, three-dimensional printing may include moving a nozzle or nozzle assembly of a three-dimensional printer in a direction of travel while dispensing (e.g., printing, extruding, passing, or the like) the solidifiable material, a tab of the nozzle or nozzle assembly of a three-dimensional printer extending in a direction opposite the direction of travel.

In some examples, moving a nozzle or nozzle assembly of a three-dimensional printer while dispensing may include rotating the nozzle or nozzle assembly such that a leading side of the nozzle or nozzle assembly faces the direction of travel and a trailing side of the nozzle faces the direction opposite the direction of travel.

In other examples, shaping deposited solidifiable material using a nozzle or nozzle assembly of a three-dimensional printer may include engaging the deposited solidifiable material with a surface of a tab of the nozzle or nozzle assembly of a three-dimensional printer to decrease a height of the deposited solidifiable material on the printing surface, the surface of the tab being non-planar relative to an outlet end of the nozzle or nozzle assembly.

In another example, depositing solidifiable material may include forming an elongated bead of extrudable building material.

In other examples, three-dimensional printing may include depositing a second elongated bead of extrudable building material onto a surface of a first elongated bead of extrudable building material.

In some examples, forming the elongated bead may comprise shaping a perimeter of the elongated bead so that the elongated bead has a polygonal cross-sectional area.

In some examples, a tab of a nozzle or nozzle assembly of a three-dimensional printer may be movable between a first position, in which the outlet is open, and a second position, in which the outlet is closed, and the body and/or the tab defining an opening in an outlet of the nozzle or nozzle assembly.

In another example, when a tab of a nozzle or nozzle assembly of a three-dimensional printer is in a first position, the opening of an outlet of the nozzle or nozzle assembly may define a polygonal cross-sectional shape.

In other examples, when a tab of a nozzle or nozzle assembly of a three-dimensional printer is in a first position, the opening of an outlet of the nozzle or nozzle assembly may define a trapezoidal cross-sectional shape.

In some examples, a dimension of an opening of an outlet of a nozzle or nozzle assembly of a three-dimensional printer may be adjustable by moving a tab between a first and second positions. In some examples, when a tab of a nozzle or nozzle assembly of a three-dimensional printer is in a third position, the opening of the outlet may define a triangular cross-sectional shape.

In another examples, a bracket may define a tab of a nozzle or nozzle assembly of a three-dimensional printer.

In other examples, a cartridge may carry a tab of a nozzle or nozzle assembly of a three-dimensional printer.

In some examples, a cartridge may be movable relative to the body of a nozzle or nozzle assembly of a three-dimensional printer.

In some examples, a bracket of a nozzle or nozzle assembly of a three-dimensional printer may be slidably coupled to the cartridge.

In some examples, a tab of a nozzle or nozzle assembly of a three-dimensional printer may be rotatable relative to a body of the nozzle or nozzle assembly of a three-dimensional printer.

In other examples, three-dimensional printing may include adjusting a location of a tab of a nozzle or nozzle assembly of a three-dimensional printer relative to an outlet of the nozzle or nozzle assembly.

In other examples, adjusting a location of a nozzle or nozzle assembly of a three-dimensional printer may include moving a tab between a first position, in which an outlet of the nozzle or nozzle assembly of a three-dimensional printer is open, and a second position, in which the outlet is closed.

In some examples, adjusting a location of a tab of a nozzle or nozzle assembly of a three-dimensional printer may include sliding a bracket along an axis perpendicular relative to a longitudinal axis of the nozzle or nozzle assembly, the bracket defining the tab.

In other examples, sliding a bracket of a nozzle or nozzle assembly of a three-dimensional printer may include sliding the bracket along a rail of a cartridge to move tab of the nozzle or nozzle assembly of a three-dimensional printer between the first position and the second position.

In other examples, adjusting a location of a tab of a nozzle or nozzle assembly of a three-dimensional printer may include rotating a cartridge relative to a body of the nozzle or nozzle assembly.

In other examples, adjusting a location of a tab of a nozzle or nozzle assembly of a three-dimensional printer may include rotating a body of the nozzle or nozzle assembly relative to the tab.

In some examples, shaping solidifiable material using a three dimensional printer nozzle or nozzle assembly may include passing solidifiable material along a flow path having a circular cross-sectional area at an inlet of a three dimensional printer nozzle or nozzle assembly and a polygonal cross-sectional area at the outlet.

In other examples, shaping the solidifiable material may include passing the solidifiable material through a trapezoidal opening of an outlet of a nozzle or nozzle assembly of a three-dimensional printer.

In another examples, three-dimensional printing may include rotating and translating a tab of a nozzle or nozzle assembly of a three-dimensional printer relative to a body of the nozzle or nozzle assembly.

In some examples, three-dimensional printing may include passing solidifiable material through a triangular opening of an outlet of a nozzle or nozzle assembly of a three-dimensional printer.

In other examples, three-dimensional printing may include moving a nozzle assembly in a direction of travel while dispensing the solidifiable material.

In some examples, a tab of a nozzle or nozzle assembly of a three-dimensional printer may extend in a direction opposite to the direction of travel of the nozzle or nozzle assembly.

In some examples, shaping deposited solidifiable material may include engaging the deposited solidifiable material with a surface of a tab of a nozzle or nozzle assembly of a three-dimensional printer to decrease a height of the deposited solidifiable material on a printing surface (i.e., a surface on which solidifiable material is deposited (i.e., extruded or printed) by a three-dimensional printer, nozzle, and/or nozzle assembly).

In some examples, a surface of a tab of a nozzle or nozzle assembly of a three-dimensional printer may be non-planar relative to an outlet end of the nozzle or nozzle assembly.

In some examples, three-dimensional printing may include moving a tab of a nozzle or nozzle assembly of a three-dimensional printer to close an outlet of the nozzle or nozzle assembly to stop depositing (i.e., extruding or printing) the solidifiable material.

DETAILED DESCRIPTION

Building structures (e.g., dwellings, buildings, sheds, etc.) may be constructed with a multitude of different materials and construction methods. Traditionally, a building structure may be constructed upon a composite slab or foundation that comprises concrete reinforced with re-bar or other metallic materials. The structure itself may then be framed (e.g., with wood and/or metal framing members), and then an outer shell and interior coverings (e.g., ply-wood, sheet rock, etc.) may be constructed around the structural framing. Utilities (e.g., water and electrical power delivery as well as vents and ducting for air conditioning and heating systems) may be enclosed within the outer shell and interior covers along with insulation. This method of designing and constructing a building structure is well known and has been successfully utilized in constructing an uncountable number of buildings; however, it requires multiple construction steps that cannot be performed simultaneously and that often require different skills and trades to complete. As a result, this process for designing and constructing a building can extend over a considerable period (e.g., 6 months to a year or more) and is somewhat labor-intensive. Such a lengthy construction period is not desirable in circumstances that call for inexpensive construction of a structure in a relatively short period of time.

Accordingly, embodiments disclosed herein include construction systems, methods of construction, and even methods for structure design that allow a building structure to be constructed in a fraction of the time associated with traditional construction methods. In particular, embodiments disclosed herein utilize additive manufacturing techniques (e.g., three-dimensional (3D) printing) in order to produce a building more quickly, economically, and in a systematic manner. Three-dimensional printing generally involves movement of a printing assembly, and a nozzle of the printing assembly, in three axes of movement across a horizontal surface of a wall structure comprising inner and outer members. The wall structure is therefore built layer-by-layer from the ground or foundation upward. As the wall is being built, or printed, the nozzle will periodically turn off and extruded building material will cease exiting the outlet to leave openings in the wall for the windows, doors, etc.

FIG.1is a perspective view of a construction system and a building structure being formed by the construction system using printed, stacked layers of elongated beads according to the present disclosure. Referring toFIG.1, a construction system10according to one embodiment is shown. Although there are multiple types of 3D additive construction systems contemplated herein, one example of a construction system10includes a gantry-type construction system. Other example construction systems can include a single tower and boom to deliver stacked layers of elongated beads onto an existing surface (e.g., a slab or foundation).

The construction system10can include a pair of railed assemblies12, a gantry14moveably disposed on rail assemblies12, and a printing assembly16moveably disposed on the gantry14. For example, the gantry14can include a bridge support18connected between a pair of vertical supports20. Also, coupled between the vertical supports20can be a trolly bridge24, on which the printing assembly is16is moveably disposed.

For example, the gantry14can move in the y-axis or y direction along the rail assemblies12, and the printing assembly16can move along the x-axis or x direction along the trolly bridge24. To complete the three orthogonal axes or dimensions of movement for the printing assembly16, the trolly bridge24can move vertically up and down along the z-axis. For example, the trolly bridge24can move up and down in the z-axis upon the vertical support members20. The x-axis is orthogonal to the y-axis and the z-axis is orthogonal to the plane formed by the x and y axes. Movement along the x, y and z-axes of the printing assembly16can occur via drive motors coupled to drive belts, chains, cables, etc., controllably from an instruction-driven processor within a peer system or controller.

The construction system10effectuates the construction of a building structure30by passing the printing assembly16above a wall structure32and emitting extruded building material from a nozzle26comprising an outlet28. Accordingly, as printing assembly16moves in three possible orthogonal axis, as well as angles there between, the outlet28emits extruded building material onto the upper surface of the wall structure32as it is being formed. The wall structure32is formed layer-by-layer by laying down an elongated bead of extruded, solidifiable material, such as, for example, a cementitious material of cement or concrete, beginning with the first layer on ground or a pre-existing foundation34.

In some examples, the nozzle26can include a structure such as a tab positioned at or near an outlet of the nozzle26. In some examples, the tab may be integrally formed with the nozzle26or the tab may be coupled so that the tab and the nozzle26are movable together and separately. Further, in some respects, the nozzle26may include a flow path with a non-uniform cross-section from a nozzle inlet to the nozzle outlet.

As each layer of elongated beads is laid down onto the foundation34or onto a previous layer, a plurality of stacked elongated beads of extruded building material additively, and three-dimensionally, form a building structure30. When the printing assembly16, and thereby the outlet28approaches an opening, such as a window opening38, or a door opening40, the pump for the extruded building material stops, and possibly a valve coupled to the outlet28, or elsewhere, shuts off the flow of extruded material, and does not resume the flow until after the outlet28moves past the opening where the wall structure32is resumed.

The foundation34can be made of concrete with metallic rods (e.g., rebar) within the foundation form. Alternatively, the foundation34can simply be ground, possibly packed gravel or crushed rock, a 3D printed foundation, or otherwise. In some respects, however, the upper surface of the foundation34should be substantially planar at its top surface and of sufficient perimeter size to accommodate 3D printing of the wall structure32thereon. The axes, labeled as x, y and z, are orthogonal axes in three dimensions; however, it is contemplated that printing assembly16and thus outlet28of the nozzle26can move in three dimensions to form a wall structure at various three-dimensional angles that can be, but need not be, orthogonal angles for the wall structure32.

In this example implementation,FIG.1shows an interior (or inner) wall structure32that can be used to bifurcate rooms of a building30using the construction system10. For example, in some respects, the interior wall structure32can have a first shell and a second shell (each defined by a wythe of stacked elongated beads), with both the first and second shells only exposed to a human-occupiable, indoor, temperature-controlled environment. Thus, in some aspects, the sides of interior wall structure32are not exposed (as designed) to an outdoor ambient environment. However, in alternative embodiments, the wall structure32can be an exterior wall structure, such that with the first shell is exposed (e.g., solely) to a human-occupiable, indoor, temperature-controlled environment and the second shell is exposed (e.g., solely) to an outdoor, ambient environment. In some aspects, both the first and second shells can be exposed to an outdoor, ambient environment.

The wall structure32, in some aspects, can form at least a portion of a non-load bearing wall (also referred to as a “partition wall” or “partition wall structure” in the present disclosure). For example, in some aspects, the wall structure32, when fully formed and cured, is sufficient to bear its own weight (e.g., holds itself upright, as well as appurtenances such as door frames, window frames, and household items fastened to the structure), but is insufficient to bear (without deformation or collapse or other movement) loads (e.g., on a top surface of the wall structure32with respect to gravity) including but not limited to compressive, flexural, shear, and uplift onto the wall structure32. For example, the wall structure32may not be capable of bearing the load of a ceiling structure in the building or a roof in which the wall structure32is constructed.

In some aspects, the wall structure32can form at least a portion of a load-bearing wall. For example, in some aspects, the wall structure32, when fully formed and cured, is sufficient to bear (without deformation or collapse or other movement) loads (e.g., on a top surface of the structure32with respect to gravity) including but not limited to compressive, flexural, shear and uplift onto the wall structure32. For example, the wall structure32can bear the load of a ceiling structure in the building or a roof in which the wall structure32is constructed.

As used herein, a ceiling structure can be a planar or angular structure that separates a human-occupiable, indoor, temperature-controlled environment from another indoor, temperature-uncontrolled environment (e.g., an attic or crawlspace). As another example, as used herein, a ceiling structure can be a planar or angular structure that separates a human-occupiable, indoor, temperature-controlled environment from another indoor, temperature-controlled environment (e.g., a separate floor of a multi-floor building). However, a ceiling structure does not include a roof that separates a human-occupiable, indoor, temperature-controlled (or uncontrolled) environment from an outdoor ambient environment. Thus, the wall structure32can be a partition wall structure in that it is insufficient to bear the weight of all or part of a roof structure and/or a load-bearing structure in that it is sufficient to bear the weight of all or part of a roof structure, wind loads, uplift, shear or other loads experienced by building structures.

FIG.2is a partial front view of the structure, and a block diagram of a control system for controlling the printing of stacked beads that form a wall structure according to the present disclosure. Referring toFIG.2, a control system50is shown in block diagram for controlling the printing of the stacked elongated beads60of the wall structure32. The control system50includes a computer system, or controller52, that contains memory and an instruction set for adding the proper amount of water or liquid mix material from a water tank54, and dry ingredients from a hopper56into a mixer58. Possibly through a feedback sense mechanism, the controller can adjust the mix of the concrete material and thus the proper proportions of water (or liquid) to dry material, and supply that proper mix to a supply tank62.

It may be desirable for the stacked elongated beads to be at the proper cross-sectional dimension which is approximately 1.5 to 2.5 inches in lateral width (e.g., parallel to the horizontal plane) and at least approximately 0.5 inches tall (e.g., perpendicular to the horizontal plane). The horizontal plane is preferably along a plane formed by the x and y axes, and the orthogonal dimension thereto is preferably along the z-axis or dimension. To maintain the proper cross-sectional dimension in the horizontal plane so that when the elongated beads are stacked, the inner and outer surfaces are relatively even in texture and somewhat smooth. The pump64can be used to supply a proper volume of extruded material to supplement the proper viscosity from the mixer58. The controller52thereby controls not only the proper flow and viscosity of the elongated bead as it is being printed, one on top of the other, but the controller52also controls movement of the printing assembly16in the x, y and z dimensions via a driver66. The driver66can be a motor coupled to any drive mechanism that moves the corresponding trolly bridge24, gantry14, and printing assembly16on the trolly bridge24according to the instruction CAD layout, and to the proper speed, established by the instructions stored in controller52.

Turning now toFIGS.2and3in combination,FIG.3illustrates an expanded breakaway view along region3ofFIG.2. Specifically,FIG.3illustrates the elongated beads stacked on top of one another to form a plurality of vertically stacked elongated beads60. In the example shown, elongated bead60bis stacked upon elongated bead60a. As the printing process continues, another elongated bead will be stacked upon bead60b, and so on. If one bead is stacked upon another bead, then the ensuing wall structure32will be one bead width in thickness, labeled T. As noted above, a wythe is a continuous plurality of vertically stacked elongated beads, and a wythe can be a single wythe of thickness T, or a multiple wythe of multiple thicknesses T depending how many elongated beads are placed adjacent one another during the printing process. Accordingly, a wythe is only one bead width in thickness, whereas a pair of wythes is two bead thickness.

It may be desirable to provide a particular shape to the elongated beads to achieve a particular design, construction, and/or aesthetic of the finished wall structure32. As shown inFIG.3, the first and second elongated beads60a,60bhave a polygonal (e.g., rectangular, trapezoidal, etc.) cross-sectional shape to achieve a flat wall design. Flat wall construction using 3D printing may reduce instances of lifting, tearing, bulging, and folding of elongated beads during the construction process.

Turning toFIGS.4-8, a first example nozzle100for 3D printing a flat wall design is constructed in accordance with the teachings of the present disclosure. The nozzle100comprises a body104comprising an inlet108, an outlet112, and a flow path116connecting the inlet108and the outlet112. The body104comprises a leading side120and a trailing side122opposite the leading side120, and first and second lateral sides124,126. A tab128positioned adjacent to the outlet112extends outwardly relative to the trailing side122of the body104. A flange132positioned adjacent to the inlet108extends radially outward relative to a longitudinal axis A of the body104. The flange132includes a plurality of apertures sized to receive fasteners for coupling the nozzle100to a conduit of the printing assembly16. In the illustrated example, the tab128and the flange132are integrally formed with the body104of the nozzle100so that the tab128and the flange132are inseparably connected to the body104. However, in other examples, the tab128and/or the flange132may be formed separately and subsequently attached to the body104in a fixed or removable manner.

The nozzle100illustrated here has a particular ornamental arrangement for the body104. While the illustrated arrangement provides all the functional benefits described here, some of the details of this particular arrangement may add to the cost of manufacture. Consequently, the illustrated nozzle100may not provide all of the possible economic advantages that might be derived from the present disclosure. On the other hand, this particular arrangement is believed to be aesthetically pleasing and is likely to be recognized and relied upon by purchasers to identify the source of the nozzle100.

The nozzle100is configured for use with a 3D printing assembly, such as the printing assembly16used in the construction system10described above and with respect toFIGS.1-2. In this example, the nozzle100is constructed to shape a solidifiable material that passes through the flow path116to provide the flat elongated beads60a,60bas shown inFIG.3. Further, the nozzle100is configured for use with a printing assembly that rotates the orientation of the nozzle100(i.e., about the z-axis ofFIG.1or A axis of the nozzle100) according to the printing path of the assembly16. Specifically, the leading side120of the body104of the nozzle100faces a direction of travel R of the printing assembly16and the trailing side122faces a direction B opposite the direction of travel R, as shown inFIG.8.

Turning briefly toFIGS.1-3, when the printing assembly16constructs a ninety degree corner42of the building structure30(e.g., where two wall structures32meet), the printing assembly16will rotate the nozzle100ninety degrees to continue dispensing solidifiable material along the printing path and form the corner42. Accordingly, the nozzle100substantially uniformly shapes the elongated beads60A,60B throughout construction of the building structure30. However, in other examples, the nozzle100may be used with a printing assembly16that does not rotate the nozzle100upon the z-axis.

Returning toFIGS.1-8, the tab128extends both laterally and longitudinally relative to an outlet end136of the nozzle100. Specifically, inFIGS.7and8, the tab128extends outwardly from the lateral sides124,126and from the trailing side122relative to the longitudinal axis A of the body104. The tab128also extends in an axial direction so that, with respect to the orientation of the nozzle100inFIG.8, the tab128is at least partially disposed above and below the outlet end136of the nozzle100. The tab128may have integrated or attachable features to facilitate construction of sharp corners. For example, inFIGS.4and11, the tab128includes first and second asymmetrical arms138A,138B that extend outwardly from respective first and second lateral sides124,126of the body104. The first arm138A has a length L measured from the trailing side122, and the second arm138B has a length L2measured from the trailing side122and that is less than the length L1of the first arm138A. However, in other examples, the tab128may have symmetrical extending arms. Further, inFIGS.5and11, the tab128comprises a dimension W that is larger than a cross-sectional dimension of the body104and/or a width of the extruded bead. In another example, the tab128may extend outwardly from one or more of the leading side120, trailing side122, and first and second lateral sides124,126.

InFIG.8, a height of the tab128measured between a first surface140and a second, opposite surface144is non-uniform. Particularly, the tab128comprises a first height H1adjacent to the lateral sides124,126of the body104and a second height H2at a location spaced from the trailing side122of the body104. The first surface140faces in a direction away from the outlet112and is relatively flat, whereas at least a portion of the second surface144is non-planar relative to the outlet end136of the nozzle100. InFIGS.1,8, and9, the second surface144has a first portion148, a second portion152, and a step156connecting the first and second portions148,152. The first portion148is planar relative to the outlet end136, and the second portion152declines at an angle α relative to the first portion148.

The first and second surfaces140,144of the tab128are non-parallel where a second height H2is greater than the first height H1to shape a solidifiable material after exiting the outlet112of the nozzle100. In particular, the tab128is configured for flattening an elongated bead as the elongated bead is deposited onto a printing surface. However, in other examples, the second surface144of the tab128may have a uniform planar surface, a gradually declining surface relative to the outlet112, an inclining surface relative to the outlet112, two or more planar portions, or other a combination of planar, stepped, and non-planar portions and features. In yet another example, the second surface144may have a surface treatment (e.g., ridges, grooves, dimples, satin finish, etc.) to shape and/or dispense the solidifiable material through the nozzle100in a desired manner.

The nozzle100also shapes the solidifiable material while the material passes through the flow path116of the body104. The body104includes a cylindrical portion160at the inlet108defining a cylindrical bore, as shown inFIGS.5-8, that transitions to a portion having a polygonal cross-section defined by the leading, trailing, and first and second lateral sides120,122,124,126. In particular, interior walls162,164,168,172,176of the body104receive a solidifiable material through a circular inlet108, as shown inFIG.10, compress and/or shape the solidifiable material in the flow path116, and deposit the solidifiable material through a trapezoidal outlet112, as shown inFIG.9. One or more of the interior walls162,164,168,172,176may be planar, angled, convex, concave, or a combination of shapes and features.

InFIGS.9-12, the body104and cross-sectional shape of the flow path116of the nozzle100are shown at various sections of the nozzle100. Beginning at the inlet108shown inFIG.10, the flow path116is defined by a cylindrical bore162of the cylindrical section160. InFIG.11, a cross-section of the flow path116transitions from the circular cross-sectional inlet108to the trapezoidal outlet112. An interior wall164of the leading side120defines a curved leading edge166, an interior wall168of the trailing side120defines a curved trailing edge170, an interior wall172of the first lateral wall124defines an angled first lateral edge174, and an interior wall176of the second lateral wall126defines an angled second lateral edge178of the flow path cross-section. Finally, inFIG.9, the cross-section of the flow path116at the outlet end136is defined by the leading edge166having a first width W1, the trailing edge170having a second width W2greater than the first width W1, and first and second lateral edges174,178. As shown in bothFIGS.9and11, the first and second lateral edges174,178of flow path cross-section are angled outwardly from the leading edge166and toward the trailing edge170. Thus, in this example implementation, the flow path116inFIG.12is defined by the cylindrical bore162, the interior wall164of the leading side120, the interior wall168of the trailing side122, the interior wall172of the first lateral side124(not shown), and the interior wall176of the second lateral side126.

However, in other examples, the first and second lateral walls124,126may be parallel to form a square or rectangular cross-section at the outlet end136. Further, while the body104of the nozzle100has sloped and angled interior and exterior walls, in another example, an exterior wall of the body104may be cylindrical and an interior wall may define a bore comprising a similarly shaped flow path as the flow path116of the nozzle100.

InFIGS.13A and13B, a third example nozzle200for a 3D printer is constructed in accordance with the teachings of the present disclosure. The second example nozzle200is similar to the first example nozzle100ofFIGS.4-12described above, with similar reference numerals used for similar components. However, the nozzle200has a different body204and tab228configuration. The second example nozzle200, when coupled to the tab228, operates in a slightly different manner than the first example nozzle100. Like the tab128of the first example nozzle100, the tab228of the second example nozzle200is positioned at an outlet212of the body204and extends outwardly from the body204. Furthermore, the tab228is configured for engaging a deposited solidifiable material to shape and minimize a height of the deposited material for a desirable flat wall construction. Accordingly, the second example nozzle400, like the first example nozzle100, may reduce material for construction and instances of lifting, tearing, bulging, and folding of elongated beads during the construction process.

The tab228of the second example nozzle200differs from the tab128of the first nozzle100and extends from all sides of the nozzle200. InFIGS.13A and13B, the tab228is a radial flange positioned at the outlet212and extends outwardly from the first lateral side220, a second lateral side opposite the first lateral side, a third lateral side224, and a fourth lateral side226opposite the third lateral side224. During printing, the nozzle200is configured for shaping a deposited elongated bead regardless of the direction of travel of the nozzle200. In other words, the nozzle200does not need to rotate about a longitudinal axis (e.g., z-axis) when changing the direction of travel because a portion of the tab228continuously trails the body204to shape a deposited elongated bead.

Additionally, an outlet end236of the nozzle200differs than the outlet end136of the first nozzle100. As shown inFIG.13B, the outlet end236has a symmetrical outlet212defined by four outlet edges166,170,174, and178. The outlet edges166,170,174,178are convex to help shape the solidifiable material and form a bead with flat surfaces and edges. In some examples, the interior walls of the body204are also be sloped with a similar radius of curvature as the outlet edges166,170,174,178. In other examples, the outlet edges166,170,174,178are curved but one or more of the interior walls are planar. In the illustrated example ofFIGS.13A and13B, the outlet edges166,170,174,178are equal in radius of curvature and in length. However, in other examples, the outlet end236may have one or more outlet edges that are different in radius of curvature and in length.

FIG.14is a diagram of an example method or process300of three-dimensionally printing (“3D printing”) in accordance with the teachings of the present disclosure. The method or process300of 3D printing may use a nozzle, such as the nozzle100ofFIGS.4-12, nozzle200ofFIGS.13A and13B, or nozzle400ofFIGS.15-20, to create a flat wall construction, such as the construction system10ofFIGS.1-3. For simplicity, the method300will be described with respect to the first example nozzle100ofFIGS.4-12. The method300includes a step304of dispensing a solidifiable material through a nozzle100comprising an inlet108, an outlet112, and a flow path116extending between the inlet108and the outlet112. The method300also includes a step308of depositing the solidifiable material onto a printing surface, thereby forming a deposited solidifiable material. Further, the method300includes a step312of shaping the deposited solidifiable material using a tab128that extends outwardly from the outlet112of the nozzle100.

Before the steps308,312of depositing and shaping, the method300may include shaping the solidifiable material against one or more sloped interior walls162,164,168,172,176of the nozzle100. For example, the interior walls164,168of the leading and trailing sides120,122are angled and/or curved inwardly inFIG.12relative to the longitudinal axis A. As the solidifiable material passes through the cylindrical bore162at the inlet108, the interior walls164,168,172,176engage the material as it passes through the flow path116, directing the material through the polygonal cross-section of the outlet. A slope of the interior wall164of the leading side120is greater than a slope of the interior wall168of the trailing side124. Further when the nozzle100moves in the direction of travel R, the nozzle100applies a compressive force to the solidifiable material in a direction B opposite the direction of travel R. As shown inFIG.12, the interior wall164of the leading side120has concave surface, whereas the interior wall168of the trailing side124has an angled, planar surface.

The method300may also include moving the nozzle100in a direction of travel R while dispensing and depositing the solidifiable material. Moving the nozzle100during the step304of dispensing the solidifiable material may comprise rotating the nozzle100such that the leading side120of the nozzle100faces the direction of travel R and the trailing side124of the nozzle100faces the direction B opposite the direction of travel R. The step308of depositing the solidifiable material may comprise forming an elongated bead (e.g., bead60aofFIG.3) of extrudable building material, and depositing a second elongated bead (e.g., bead60bofFIG.3) of extrudable building material onto a flat surface of the elongated bead60a. Forming the elongated beads60a,60bmay include shaping a perimeter of each elongated bead60a,60bso that the elongated bead60a,60bhas a polygonal cross-sectional area. During printing300, the trapezoidal opening of the outlet112of the nozzle100forms the trapezoidal cross-sectional shape of the elongated beads60a,60b.

As the nozzle100moves in the direction of travel R, the step312of shaping the deposited material may be performed. The step312of shaping may comprise engaging the deposited solidifiable material with a surface of the tab128(e.g., the second surface144) to decrease a height of the deposited solidifiable material on the printing surface. The surface144of the tab128decreases the height of the deposited solidifiable material by compressing the deposited material with a sloped, angled, or stepped surface144relative to the outlet end136of the nozzle100. The method or process300may be performed using a different nozzle100, such as, for example, the second example nozzle200and a third example nozzle100ofFIG.15.

InFIG.15, a printing assembly316comprising a third example nozzle400is assembled in accordance with the teachings of the present disclosure. The printing assembly316comprises a conduit402that is coupled to an inlet of the nozzle400and in fluid communication with a flow path of a body404of the nozzle400. The third example nozzle400is similar to the first example nozzle100ofFIGS.4-12described above, with similar reference numerals used for similar components. However, the nozzle400has a different body404and tab428configuration. The third example nozzle400, when coupled to the tab428, operates in a slightly different manner than the first example nozzle100. Like the tab128of the first example nozzle100, the tab428of the third example nozzle400is positioned at an outlet412of the body404and extends outwardly from a trailing side. Furthermore, the tab428is configured for engaging a deposited solidifiable material to shape and minimize a height of the deposited material for a desirable flat wall construction. Accordingly, the third example nozzle400, like the first example nozzle100, may reduce material for construction and instances of lifting, tearing, bulging, and folding of elongated beads during the construction process.

The third example nozzle400differs from the first example nozzle100in a few ways. First, the body404of the third example nozzle400has a uniform cylindrical exterior surface460. However, similar to the body104of the first example nozzle100, the body404of the third example nozzle400comprises one or more interior walls that are arranged to shape a solidifiable material as it enters an inlet with a circular cross-section and passes through the outlet112with a trapezoidal cross-section. An interior wall of the leading side420is non-parallel to an interior wall of the trailing side. The interior wall of the leading side420partially defines the flow path and has a sloped interior surface. Similarly, the interior wall of the trailing side has a sloped interior surface.

Second, the tab428is movable relative to the outlet412between a first position, in which the outlet412is open, as shown inFIG.15, and a second position, in which the outlet412is closed, as shown inFIG.16. The tab428is coupled to the body404via a cartridge340and is not integrally formed with the body404of the nozzle400, and is arranged on a bracket430that is slidably coupled to first and second rails346,348of the cartridge340. Accordingly, the body404may be separately rotatable about a longitudinal axis E or adjusted relative to the cartridge340. In this way, the deposited shape of the solidifiable material may be changed by rotating the orientation of the outlet412relative to the tab428.

Finally, the position of the tab428relative to the outlet end412of the body404is adjustable. An operator may adjust the position of the tab428relative to the body404by sliding the bracket430along one or more rails404of the cartridge340in a direction perpendicular F to a longitudinal axis E of the nozzle400. In this way, the size and shape of the outlet412may change by disposing the tab428inwardly and/or outwardly relative to the outlet412. Accordingly, a leading edge of the tab428may extend into and cut-off the flow path at the outlet412of the nozzle400. Together with the rotatable movement of the body404, the tab428may adjust the cross-sectional shape at the outlet412to achieve a shape that is different from the outlet end436of the body404. For example, inFIG.15the outlet end436is trapezoidal. By rotating the body404about the E axis and translating the tab428along the F axis to partially cover the opening of the outlet412, the tab428and body404of the nozzle400may be arranged to define a variety of openings of different shapes and sizes. In some examples, the tab428may be actuated to slide over the outlet412and cut-off the material (or close the outlet112) during the printing process and/or at the end of the printing path. Further, the sliding tab arrangement may be particularly helpful when changing the size and shape and/or closing the outlet412of the nozzle400. By completely covering the outlet412with the tab428, as shown inFIG.15, the tab428keeps any material disposed in the body404or conduit of the assembly316from falling out during translation of the nozzle400. Additionally, this arrangement may help purge air from the 3D printing line.

The rotational and translation tab arrangement of the nozzle assembly316assists in 3D printing a structure having a corner requiring less material than a structure having a linear path.FIG.20illustrates various points during a printing path of a corner at which the nozzle assembly316may change to achieve a desirable cross-sectional output. While moving linearly in the direction of travel R, the tab428of the nozzle assembly316is in the first position (FIG.17) to extrude an elongated bead with a rectangular or trapezoidal cross-section517. To print the corner42along the printing path500, the tab428slides along the F axis to a third position, between the first and second positions. In the third position, the tab428partially covers the outlet412. As shown inFIG.18, the cartridge340rotates in a G direction about the longitudinal E axis of the body104(or in other examples, the body404and/or cartridge340rotates about the E axis) so that the body404and the tab428define a triangular cross-sectional opening at the outlet412. The triangular opening at the outlet412corresponds to a triangular cross-section of the elongated bead518shown inFIG.20. A triangular cross-sectional outlet412reduces the amount of extrudable material flowing through the nozzle400as the assembly316makes the right turn, or other tight corners with a small radii, along the printing path500. Through arc of the travel path at the corner42, the bracket430may remain in the position shown inFIG.18, or may slide the tab428further into the flow path416at the outlet412to decrease a cross-sectional size of the opening of the outlet412. The material extrusion rate may be controlled according to the cross-sectional shape of the material exit (e.g., if the cross-section is reduced, the material flow is reduced accordingly). After completing the right turn, the nozzle assembly316may return the tab428and cartridge340to the original positioning shown inFIG.17for extruding an elongated bead with a rectangular or trapezoidal cross-section.FIG.19is an example configuration of the nozzle assembly316when making a left turn to print a corner. InFIG.19, the cartridge430rotates in the J direction about the E axis of the body404(and/or rotating the body404about the E axis in another example) and the tab428translates along the F axis to partially cover the outlet412and to define the triangular cross-sectional opening of the outlet412. For corners with greater radii, the outlet opening may be reduced to a smaller quadrilateral, instead of a triangle used for smaller radii.

In the illustrated example, both the tab428and the body404are movable relative to the other component to adjust the shape of the flow path at the outlet412. However, in other examples, the tab428may be arranged to both translate along (or in a direction parallel to) the F axis and rotate about the E axis to adjust the outlet shape of the flow path. In yet other examples, the body404may be arranged to both rotate about the E axis and translate (along or in a direction parallel to the F axis) relative to the tab428to adjust the outlet shape of the flow path.

The nozzles100,200,400may be manufactured from any suitable material, and in some examples, are formed by a 3D printing method using a tough resin. For example, the nozzles100,200,400may be manufactured using stereolithography (SLA) 3D printer. In other examples, the nozzles100,200,400may be manufactured using other additive manufacturing techniques, or from an extrudable material including extrudable polymers and/or metals. In some examples, the nozzles100,200,400may be formed by injection molding, thermoforming, or compression molding. In some examples, the nozzles100,200,400may be a durable plastic, such as polyethylene, metal, fiberglass, or other similar materials, or any combination of these materials.

The first, second, and third example 3D printing nozzles100,200,400disclosed herein advantageously shape solidifiable material to improve construction, design, and appearance of flat wall 3D printed construction.

First, the orientation and shape of the tabs128,228,428of the nozzles100,200, and400help flatten deposited solidifiable material during printing of wall construction. Specifically, the tabs128,228,428(and/or a portion of the tab) are disposed at the trailing side of the nozzle100,200,400and have a height that increases away from the outlet112,212, and412. The orientation and dimension of the tabs128,228,428help smooth and flatten lifted corners and over-extruded corners of deposited material. Additionally, the tabs128,228,428compress the deposited material to improve double-layer bonding between deposited beads and to achieve a uniformly level top surface of the deposited bead. The nozzles100,200,400help reduce bulging and folding, thereby reducing material to form a wythe of a decreased width without compromising strength. Thus, 3D printing using the nozzles100,200,400ofFIGS.4-13B and15-19may reduce construction costs and avoid corrugated wall surfaces that collect dust.

Further, the shape of the flow path of the nozzles100,200,400reduce a natural tendency of solidifiable material to bulge after exiting the outlet112,212,412of the nozzle100,200,400. Typically, when solidifiable material is injected through a rectangular or circular cross-section, for example, the solidifiable material tends to bulge. To compensate for this behavior, the interior surfaces of each nozzle100,200,400are sloped (e.g., angled, curved, etc.) inwardly relative to longitudinal axes A, E to apply a compressive force to the solidifiable material as it engages the interior walls of the nozzles100,200,400. A combination of both (a) shape of each nozzle flow path that transitions from a circular inlet to a trapezoidal outlet, and (b) movement of the nozzle so that an interior wall of the leading side applies a compressive force to the solidifiable material (in a direction opposite the direction of travel) achieves a flat and level layer of solidifiable material. In particular, the curved interior wall164of the leading side120of the first example nozzle100, for example, helps shape a bottom surface of the bead being printed. The curved wall164compensates for the tendency for the solidifiable material to bulge (i.e., the self-weight deformation of the solidifiable material) and shapes a bead with flat surfaces and sides to reduce a likelihood of forming a gap or space between the bead being printed and a deposited bead. The curved outlet edges of the second nozzle200and one or more of the interior walls of the third example nozzle400are also curved to form a flat sided bead.

The second example nozzle200is shaped so that a printing assembly can limit movement of the nozzle during the printing process. As previously discussed, the tab228of the nozzle200extends radially outward from the body204. So configured, the tab228may trail the leading side of the nozzle200in any direction of travel, thereby simplifying the 3D printing method or process.

Further, the nozzle assembly316may control material extrusion rate by changing the arrangement of the tab428and body404to manage material usage and perform more complicated printing procedures. As previously discussed, corner construction may require less material than linear wall construction. The nozzle assembly316is therefore configured to alter the amount of material flowing through the nozzle400during a printing path by moving the tab428and/or body404to change a size and/or a shape of the outlet opening.

FIG.21is a schematic illustration of an example control system for a construction system used to construct a wall structure according to the present disclosure. For example, all or parts of the controller700can be used for the operations described previously, for example as or as part of the controller52. The controller700is intended to include various forms of digital computers, such as printed circuit boards (PCB), processors, digital circuitry, or otherwise. Additionally, the system can include portable storage media, such as Universal Serial Bus (USB) flash drives. For example, the USB flash drives may store operating systems and other applications. The USB flash drives can include input/output components, such as a wireless transmitter or USB connector that may be inserted into a USB port of another computing device.

The controller700includes a processor710, a memory720, a storage device730, and an input/output device740. Each of the components710,720,730, and740are interconnected using a system bus750. The processor710is capable of processing instructions for execution within the controller700. The processor may be designed using any of a number of architectures. For example, the processor710may be a CISC (Complex Instruction Set Computers) processor, a RISC (Reduced Instruction Set Computer) processor, or a MISC (Minimal Instruction Set Computer) processor.

In one implementation, the processor710is a single-threaded processor. In another implementation, the processor710is a multi-threaded processor. The processor710is capable of processing instructions stored in the memory720or on the storage device730to display graphical information for a user interface on the input/output device740.

The memory720stores information within the controller700. In one implementation, the memory720is a computer-readable medium. In one implementation, the memory720is a volatile memory unit. In another implementation, the memory720is a non-volatile memory unit.

The storage device730is capable of providing mass storage for the controller700. In one implementation, the storage device730is a computer-readable medium. In various different implementations, the storage device730may be a floppy disk device, a hard disk device, an optical disk device, a tape device, flash memory, a solid state device (SSD), or a combination thereof.

The input/output device740provides input/output operations for the controller700. In one implementation, the input/output device740includes a keyboard and/or pointing device. In another implementation, the input/output device740includes a display unit for displaying graphical user interfaces.

As used herein, the terms “about,” “approximately,” “substantially,” “generally,” and the like mean plus or minus 10% of the stated value or range. In addition, as used herein, an “extruded building material” refers to a building material that may be delivered or conveyed through a conduit (e.g., such as a flexible conduit) and extruded (e.g., via a nozzle or pipe) in a desired location. In some embodiments, an extruded building material includes a cementitious mixture (e.g., concrete, cement, etc.).