具体实施方式：
[0011]FIG. 1 illustrates an exemplary system 10 for additively manufacturing sporting equipment 12. System 10 may implement any number of different additive processes during manufacture of sporting equipment 12. For example, sporting equipment 12 is shown in FIG. 1 as being manufactured via a first additive process and via a second additive process. It should be noted that the first and second additive processes may be performed simultaneously or consecutively, as desired. It should also be noted that sporting equipment 12 may be manufactured utilizing only one of the first and second additive processes.
[0012]The first additive process (represented in the lower-left of FIG. 1) may be a pultrusion and/or extrusion process, which creates hollow tubular structures 14 from a composite material (e.g., a material having a matrix and at least one continuous fiber). One or more heads 16 may be coupled to a support 18 (e.g., to a robotic arm) that is capable of moving head(s) 16 in multiple directions during discharge of structures 14, such that resulting longitudinal axes 20 of structures 14 are three-dimensional. Such a head is disclosed, for example, in U.S. patent application Ser. Nos. 15/130,412 and 15/130,207, all of which are incorporated herein in their entireties by reference.
[0013]Head(s) 16 may be configured to receive or otherwise contain the matrix material. The matrix material may include any type of liquid resin (e.g., a zero-volatile organic compound resin) that is curable. Exemplary matrixes include thermosets, single- or multi-part epoxy resins, polyester resins, cationic epoxies, acrylated epoxies, urethanes, esters, thermoplastics, photopolymers, polyepoxides, thiols, alkenes, thiol-enes, and more. In one embodiment, the pressure of the matrix material inside of head(s) 16 may be generated by an external device (e.g., an extruder or another type of pump) that is fluidly connected to head(s) 16 via corresponding conduits (not shown). In another embodiment, however, the pressure may be generated completely inside of head(s) 16 by a similar type of device and/or simply be the result of gravity acting on the matrix material. In some instances, the matrix material inside head(s) 16 may need to be kept cool and/or dark in order to inhibit premature curing; while in other instances, the matrix material may need to be kept warm for the same reason. In either situation, head(s) 16 may be specially configured (e.g., insulated, chilled, and/or warmed) to provide for these needs.
[0014]The matrix material stored inside head(s) 16 may be used to coat any number of continuous fibers and, together with the fibers F make up walls of composite structures 14. The fibers may include single strands, a tow or roving of several strands, or a weave of many strands. The strands may include, for example, carbon fibers, vegetable fibers, wood fibers, mineral fibers, glass fibers, metallic wires, SiC Ceramic fibers, basalt fibers, etc. The fibers may be coated with the matrix material while the fibers are inside head(s) 16, while the fibers are being passed to head(s) 16, and/or while the fibers are discharging from head(s) 16, as desired. In some embodiments, a filler material (e.g., chopped fibers) may be mixed with the matrix material before and/or after the matrix material coats the fibers. The matrix material, the dry fibers, fibers already coated with the matrix material, and/or the filler may be transported into head(s) 16 in any manner apparent to one skilled in the art. The matrix-coated fibers may then pass over a centralized diverter (not shown) located at a mouth of head(s) 16, where the resin is caused to cure (e.g., from the inside-out, from the outside-in, or both) by way of one or more cure enhancers (e.g., UV lights, ultrasonic emitters, microwave generators, chillers, etc.) 22.
[0015]In embodiments where sporting equipment 12 is made up of multiple structures 14, each structure 14 may be discharged adjacent another structure 14 and/or overlap a previously discharged structure 14. In this arrangement, subsequent curing of the liquid resin within neighboring structures 14 may bond structures 14 together. Any number of structures 14 may be grouped together and have any trajectory required to generate the desired shape of sporting equipment 12.
[0016]In some embodiments, a fill material (e.g., an insulator, a conductor, an optic, a surface finish, etc.) could be deposited inside and/or outside of structures 14 while structures 14 are being formed. For example, a hollow shaft (not shown) could extend through a center of and/or over any of the associated head(s) 16. A supply of material (e.g., a liquid supply, a foam supply, a solid supply, a gas supply, etc.) could then be connected with an end of the hollow shaft, and the material forced through the hollow shaft and onto particular surfaces (i.e., interior and/or exterior surfaces) of structure 14. It is contemplated that the same cure enhancer(s) 22 used to cure structure 14 could also be used to cure the fill material, if desired, or that additional dedicated cure enhancer(s) (not shown) could be used for this purpose. The fill materials could allow one or more of structures 14 to function as tanks, passages, conduits, ducts, etc.
[0017]The second additive manufacturing process (represented in the upper-right of FIG. 1) may also be a pultrusion and/or extrusion process. However, instead of creating hollow tubular structures 14, the second additive manufacturing process may be used to discharge tracks, ribbons, and/or sheets of composite material (e.g., over tubular structures 14 and/or over other features of sporting equipment 12). In particular, one or more heads 24 may be coupled to a support 26 (e.g., to an overhead gantry) that is capable of moving head(s) 24 in multiple directions during fabrication of sporting equipment 12, such that resulting contours of sporting equipment 12 are three-dimensional.
[0018]Head 24 may be similar to head 16 and configured to receive or otherwise contain a matrix material (e.g., the same matrix material contained within head 16). The matrix material stored inside head(s) 24 may be used to coat any number of separate fibers, allowing the fibers to make up centralized reinforcements of the discharging tracks, ribbons, and/or sheets. The fibers may include single strands, a tow or roving of several strands, or a weave of multiple strands. The strands may include, for example, carbon fibers, vegetable fibers, wood fibers, mineral fibers, glass fibers, metallic wires, etc. The fibers may be coated with the matrix material while the fibers are inside head(s) 24, while the fibers are being passed to head(s) 24, and/or while the fibers are discharging from head(s) 24, as desired. The matrix material, the dry fibers, and/or fibers already coated with the matrix material may be transported into head(s) 24 in any manner apparent to one skilled in the art. The matrix-coated fibers may then pass through one or more circular orifices, rectangular orifices, triangular orifices, or orifices of another curved or polygonal shape, where the fibers are pressed together and the resin is caused to cure by way of one or more cure enhancers 22.
[0019]As described above, the first and second additive manufacturing processes can be extrusion or pultrusion processes. For example, extrusion may occur when the liquid resin matrix and the associated continuous fibers are pushed from head(s) 16 and/or head(s) 24 during the movement of supports 18 and/or 26. Pultrusion may occur after a length of resin-coated fibers is connected to an anchor (not shown) and cured, followed by movement of head(s) 16 and/or head(s) 24 away from the anchor. The movement of head(s) 16 and/or head(s) 24 away from the anchor may cause the fibers to be pulled from the respective head(s) along with the coating of the matrix material.
[0020]In some embodiments, pultrusion may be selectively implemented to generate tension in the fibers that make up sporting equipment 12 and that remains after curing. In particular, as the fibers are being pulled from the respective head(s), the fibers may be caused to stretch. This stretching may create tension within the fibers. As long as the matrix surrounding the fibers cures and hardens while the fibers are stretched, at least some of this tension may remain in the fibers and function to increase a strength of the resulting composite structure.
[0021]Structures fabricated via conventional pultrusion methods may have increased strength in only a single direction (e.g., in the one direction in which fibers were pulled through the corresponding die prior to resin impregnation and curing). However, in the disclosed embodiment, the increased strength in sporting equipment 12 caused by residual tension within the corresponding fibers may be realized in the axial direction of each of the fibers. And because each fiber could be pulled in a different direction when being discharged by head(s) 16 and/or 24, the tension-related strength increase may be realized in multiple (e.g., innumerable) different directions.
[0022]Structures fabricated via conventional pultrusion methods may have strength increased to only a single level (e.g., to a level proportionate to an amount in which the fibers were stretched by a pulling machine prior to resin impregnation and curing). However, in the disclosed embodiment, because the matrix surrounding each fiber may be cured and harden immediately upon discharge, the force pulling on the fiber may be continuously varied along the length of the fiber, such that different segments of the same fiber are stretched by different amounts. Accordingly, the residual tensile stress induced within each of the different segments of each fiber may also be different, resulting in a variable strength within different areas of sporting equipment 12. This may be beneficial in variably loaded areas of sporting equipment 12.
[0023]FIG. 2 illustrates an exemplary embodiment of sporting equipment 12, which can be manufactured using one or both of the additive processes described above. In this embodiment, sporting equipment 12 is a racket, such as can be used for tennis, racquetball, badminton, squash, pickleball, etc. As a racket, sporting equipment 12 may include, among other things, a head 28, a handle 30, and a throat 32 connecting head 28 to handle 30. Head 28 may include a generally rounded (e.g., circular, ellipsoid, oval, etc.) beam 34 that at least partially surrounds and supports a webbing (e.g., a network of strings) 36.
[0024]As shown in the upper-left enlargement of FIG. 2, beam 34 may be integral with webbing 36. In particular, beam 34 and webbing 36 may be manufactured simultaneously via the second additive process described above. For example, head 24 (referring to FIG. 1) may discharge matrix-coated fibers while being moved by support 26 in a circular pattern to form a portion of beam 34, then in a linear pattern to form a portion of webbing 36, and then again in the circular pattern to form another portion of beam 34. In this way, webbing 36 may be fabricated at the same time that a thickness and/or width of beam 34 is being built up. Beam 34 and/or webbing 36 may consist of any number of different fibers (e.g., fibers of different materials, sizes, colors, and/or cross-sectional shapes) crisscrossing each other in any pattern, at any location, and with any desired density.
[0025]In one exemplary embodiment, some of the fibers within the composite material making up one or more portions of sporting equipment 12 have unique characteristics. For example, while a majority of sporting equipment 12 may comprise a structural type fiber Fs (e.g., carbon fibers, glass fibers, or aramid fibers such as Kevlar fibers), some portions of sporting equipment 12 may include a functional type of fiber Ff (e.g., electrically conductive fibers, optical fibers, shape memory fibers, etc.). The functional type of fibers Ff may be selectively interwoven with the structural type fibers Fs at strategic locations. For example, electrically conductive fibers Ff may be located at high-stress regions (e.g., at the intersection of throat 32 with head 28 and/or handle 30) and used as strain gauges to detect loading conditions of sporting equipment 12.
[0026]In a similar manner, optical fibers Ff may be located at high-stress regions (e.g., within webbing 34) and an energy beam passed therethrough. As the strings of webbing 34 flex, the optical fibers Ff may be squeezed and/or closed, thereby generating an optical feedback signal indicative of the flexing. This information may be used to determine a ball-strike location on head 28, a swing strength, a ball speed, a strike timing, etc. In some embodiments, a receiving and/or interpreting device (e.g., an interrogator) may be embedded within the sporting equipment 12 to receive, interpret, respond to, and/or remotely transmit the information.
[0027]The electrically conductive fibers Ff and/or the optical fibers Ff may be coated with another material (e.g., insulation, a strength enhancing layer, etc.), if desired. It is also contemplated that other functional components (e.g., resistors, capacitors, LEDs, switches, batteries, filters, etc.) 38 may be integrated into the functional fibers Ff and extruded through heads 16, 24, and/or automatically picked-and-placed (e.g., via attachments associated with heads 16 and/or 24) during discharge of the functional fibers Ff. Operation of these components and/or of the structural fibers Fs may be selectively tuned in these instances, for example by adjusting a shape, tension, type, and/or size of the structural fibers Fs based on feedback provided by the functional fibers Ff.
[0028]The configuration of the structural fibers Fs within webbing 36 (and/or the location/orientation relationship to beam 34) may be adjustable and/or user-customizable. Specifically, the material type, fiber size, color, shape, pattern, location, orientation, and/or density may be selectively adjusted (e.g., prior to and/or on the fly during fabrication) to provide a desired appearance and/or performance (e.g., weight, balance, strength, flexibility, shape, contour, etc.) of sporting equipment 12. These adjustments may be manually selected by an end-user and/or automatically selected based on characteristics of the user (e.g., based on a body scan of the user, monitored performance of the user, etc.).
[0029]Although beam 34 and webbing 36 have been described above as being manufactured simultaneously, it is contemplated that all of sporting equipment 12 may be manufactured together as an integral monolithic structure, in some embodiments. For example, head 28, handle 30, and throat 32 may be fabricated together (e.g., at the same time as and without separation from each other). In particular, the structural fibers Fs discharging from head(s) 16 and/or 24 (referring to FIG. 1) may be continuous through each of these components, such that thousands (or millions) of fibers Fs extend through the intersections between head 28, handle 30, and throat 32, thereby creating a strong mechanical connection without requiring the use of specialized hardware, glues, and/or heavy fasteners. It should be noted that, although head 28, handle 30, and throat 32 have been described above as being fabricated together as a single monolithic structure, one or more of these components could be fabricated separately and later joined (e.g., via chemical and/or mechanical means) to each other.
[0030]Structures fabricated via conventional pultrusion and/or extrusion methods may be limited in the orientation of the associated fibers. That is, the fibers may be generally overlapping and lie in parallel layers. However, as shown in the lower-left enlargement of FIG. 2, because the matrix surrounding each fiber may be cured and harden immediately upon discharge, the fibers may be caused to extend into free space without additional support. That is, the fibers may not be required to lie in flat layers on top of each other. Accordingly, the fibers making up handle 30 and/or throat 32 may be oriented in directions that are non-parallel (e.g., perpendicular) to each other in three dimensions. For example, the lower-left enlargement illustrates straight fibers that extend in an axial direction of handle 30, and spiraling fibers that wrap around and/or weave in-and-out of the straight fibers. This may allow for interlocking of fiber layers and/or for the creation of unique (e.g., strengthening, rigidity-enhancing, flexibility-enhancing, and/or vibration-dampening) features.
[0031]Portions (e.g., handle 30, throat 32, and/or beam 34) of the exemplary sporting equipment 12 shown in FIG. 2 may also or alternatively be manufactured using the first additive process described above. For example, tubular features (e.g., an inner core, an outer grip, etc.) of sporting equipment 12 may be fabricated using the first additive process. These features may be formed inside of and/or external to other features manufactured via the second additive process.
[0032]In the exemplary embodiment shown in FIG. 2, the matrix within the composite material making up one or more portions of sporting equipment 12 has unique characteristics. For example, while a majority of handle 30, throat 32, and/or beam 34 may comprise a structural-type matrix (e.g., a conventional UV curable liquid resin, such as an acrylated epoxy), some portions of sporting equipment 12 may include another type of matrix (e.g., a matrix that remains somewhat flexible after curing). The other type of matrix may be selectively used to coat the fibers at strategic locations. For example, the flexible matrix may be fed into head 16 and/or 24, as they near a grip portion of handle 30 and/or webbing 36, such that the resulting composite material functions as a spring and/or dampener in these areas.
[0033]FIG. 3 illustrates another exemplary embodiment of sporting equipment 12, which can be manufactured using one or both of the additive processes described above. In this embodiment, sporting equipment 12 is a club or stick, such as can be used for golf, hockey, polo, etc. As a club or stick, sporting equipment 12 may include, among other things, a head 40, a shaft 42 extending from head 40, and a grip 44 connected to an end of shaft 42 opposite head 40. Head 40 may be available in a variety of shapes, ranging from bulbous or blocky to that of a blade. Regardless of the shape, head 40 may include a face portion 46 having a toe end 46a, and a heel end 46b located opposite toe end 46a. Shaft 42 may be generally cylindrical and connect to head 40 at heel end 46b. Grip 44 may provide a gripping texture and function to dampen vibrations within shaft 42.
[0034]Similar to the embodiment of FIG. 2, any two or more of the different components of sporting equipment 12 may be integrally formed with each other. For example, head 40 and shaft 42 may be formed as a single monolithic structure. Likewise, shaft 42 and grip 44 may be formed as a single monolithic structure. And finally, all of head 40, shaft 42, and grip 44 may be formed as a single monolithic structure, if desired. When any two or more components of sporting equipment 12 are simultaneously manufactured to form a single monolithic structure, some or all of the fibers discharging from head(s) 16 and/or 24 (referring to FIG. 1) may be continuous through each of these components, such that thousands (if not millions) of fibers extend through intersections between the components, thereby creating strong mechanical connections without requiring the use of specialized hardware, glues, and/or heavy fasteners. It should be noted that, although head 40, shaft 42, and grip 44 have been described above as being fabricated together as a single monolithic structure, one or more of these components could be fabricated separately and later joined (e.g., via chemical and/or mechanical means) to each other.
[0035]Each of these components may be formed via any combination of the first and second additive processes described above, and may include of any number of different fibers (e.g., fibers of different materials, sizes, colors, and/or cross-sectional shapes) overlapping and/or interweaving with each other in any pattern, at any location, and with any desired density.
[0036]In one exemplary embodiment, some of the fibers within the composite material making up one or more portions of sporting equipment 12 have unique characteristics. For example, while a majority of sporting equipment 12 may comprise a structural type fiber Fs (e.g., carbon fibers, fiberglass, or Kevlar fibers), some portions of sporting equipment 12 may include a functional type of fiber Ff (e.g., electrically conductive fibers, optical fibers, shape memory fibers, etc.). The functional type of fibers Ff may be selectively interwoven with the structural type fibers Fs at strategic locations. For example, electrically conductive fibers Ff may be located at high-stress regions (e.g., at the intersection of shaft 42 with head 40) and used as strain gauges to detect loading conditions of sporting equipment 12.
[0037]In a similar manner optical fibers Ff may be located at high-stress regions (e.g., within face portion 46) and an energy beam passed therethrough. As face portion 46 flexes, the optical fibers Ff may be squeezed and/or closed, thereby generating an optical feedback signal indicative of the flexing. This information may be used to determine a ball-strike location on head 40, a swing strength or direction, a ball speed or trajectory, a swing or strike timing, etc.
[0038]The electrically conductive fibers Ff and/or the optical fibers Ff may be coated with another material (e.g., insulation, a strength enhancing layer, etc.), if desired. Additionally, other electrical components (e.g., resistors, capacitors, etc.) 48 may be extruded through heads 16, 24 and/or automatically picked-and-placed (e.g., via attachments associated with heads 16 and/or 24) during discharge of the fibers Ff. Operation of these components and/or of fibers Ff may be selectively tuned in these instances, for example by adjusting a shape, tension, type, and/or size of the structural fibers Fs.
[0039]The configuration of fibers within head 40, shaft 42 (and/or the location/orientation relationship between head 40 and shaft 42), and/or grip 44 may be adjustable and/or user-customizable. For example, the material type, fiber size, color, shape, pattern, location, orientation, and/or density may be selectively adjusted to provide a desired performance (e.g., weight, balance, strength, flexibility, shape, contour, etc.) of sporting equipment 12. These adjustments may be manually selected by an end-user and/or automatically selected based on characteristics of the user (e.g., based on a body scan of the user, monitored performance of the user, etc.).
[0040]As shown in the enlargement of FIG. 3, because the matrix surrounding each fiber may be cured and harden immediately upon discharge, the fibers may not be required to lie in parallel flat layers on top of each other. Accordingly, the fibers making up head 40, shaft 42, and/or grip 44 may be oriented in any desired direction. This may allow for interlocking of fiber layers and/or for the creation of unique (e.g., strengthening, rigidity-enhancing, flexibility-enhancing, vibration-dampening, and/or directional-control) features.
[0041]In the exemplary embodiment shown in FIG. 3, the matrix within the composite material making up one or more portions of sporting equipment 12 has unique characteristics. For example, while a majority of head 40 and/or shaft 42 may comprise a structural-type matrix (e.g., a conventional UV curable liquid resin, such as an acrylated epoxy), some portions of sporting equipment 12 (e.g., grip 44) may include another type of matrix (e.g., a matrix that remains somewhat flexible after curing). The other type of matrix may be selectively used to coat the fibers at strategic locations. The resulting composite material may function as a spring and/or dampener in these areas.
INDUSTRIAL APPLICABILITY
[0042]The disclosed arrangements and designs of sporting equipment 12 may be used in connection with any sporting event. Sporting equipment 12 may be light-weight and low-cost, due to a reduction in the number of fasteners required to join the various components to each other. In addition, sporting equipment 12 may be light-weight do to the use of composite materials. High-performance may be provided in the unique ways that particular fibers, resins, and functional components are used and laid out within sporting equipment 12.
[0043]It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed sporting equipment. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed sporting equipment. For example, although sporting equipment 12 is described above as being fabricated from matrix-wetted reinforcements, it is contemplated that portions (e.g., structurally insignificant areas and/or an outer skin) of sporting equipment 12 may be fabricated from only the matrix, if desired. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims and their equivalents.