Panels and composite panel assemblies and methods for manufacturing same

Abstract

A method of manufacturing and article of manufacture thereof in which a honeycomb or lattice structure with variable cell height is produced using a two-dimensional (planar) cutting method applied to a honeycomb or lattice structure that is loaded and deformed against a three-dimensional tool. After the load is removed, the panel relaxes, and a variable cell height structure is realized. The variable cell height structure can be assembled to a secondary structure or series of stacked layers along mating surface interfaces in which cells may be vertically aligned or intentionally offset throughout the cross section of the panel. A honeycomb, structural foam or lattice structure with constant or variable (cell) height may also be stacked or combined with a natural, polymeric, or foam layer of constant or variable thickness to produce a structural core with a resultant thickness that is constant or variable.

Description

Attorney Docket No. 17926-OOOOQ3-WO-POAPANELS AND COMPOSITE PANEL ASSEMBLIES ANDMETHODS FOR MANUFACTURING SAMECROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 729,281, filed on December 6, 2024, the entire disclosure of which is hereby incorporated by reference.BACKGROUNDField

[0002] The present disclosure relates to panels and composite panel assemblies and methods for manufacturing the panels and composite panel assemblies. The panels can include a honeycomb or lattice structure formed from a plurality of cells and / or structural foam. The cells can vary in height across the panel or a section of the panel. The panels can be stacked to form a composite panel assembly, including top and bottom panels or layers and a core panel or layer.Related Art

[0003] The concept of honeycomb structures as an engineered solution originated in the early 20th century when advancements in material science and manufacturing processes enabled the creation of synthetic honeycomb or lattice panels. Honeycomb structures have been a critical element of engineered structures and products across various industries due to their remarkable strength, stiffness, and lightweight properties. Inspired by natural honeycombs found in beehives, engineered honeycomb panels or cores have been used for decades to create composite panels and other structural components that require high strength and / or stiffness-to-weight ratios for critical sections of a design. These structures are typically made from a variety of materials, including metals such as aluminum or titanium, paper, polymers including thermoplastics and thermosets, and advanced composites.

[0004] Traditionally, honeycomb or lattice panels having a constant thickness are laminated on the top and bottom with a combination of textile material and / or structural composite material to form a composite panel structure. This “sandwich” construction is particularly effective because higher strength to weight and / or stiffness to weight materials (such as carbon fiber, aramid, or fiberglass) can be used to form the top and bottom of the panel, where peak compressive andAttorney Docket No. 17926-OOOOQ3-WO-POA tensile stresses are experienced when a multi-panel construction when subjected to bending loads. This construction also allows lighter, less strong or stiff materials (such as honeycomb, lattice, or structural foam) to be used closer to the center of the composite panel where little or zero stress is experienced (the so-called neutral axis, see, e.g., FIG. 12) and leveraged to reduce the overall weight of the composite panel without sacrificing strength or stiffness.

[0005] Honeycomb panels are extensively used in the aerospace industry as a fundamental element in composite panel structures. These composite panel structures typically include thin, high-strength face sheets bonded to a lightweight honeycomb panel. Typically, the face sheets are parallel to one another and both the panel and composite panel have a constant cross- sectional thicknesses. Such configurations are widely utilized in aircraft interiors, floorboards, radomes, and aerodynamic surfaces, for weight reduction without sacrificing strength.Honeycomb panels in aerospace applications are often made from high-strength aluminum, Nomex® aramid fiber, polymeric materials, or carbon fiber-reinforced polymers.

[0006] In the automotive industry, honeycomb panels are utilized to create lightweight body panels, crash absorbers, structural panels, and engineered structures. Modern electric vehicles have particularly benefited from honeycomb panels, as reducing weight directly improves battery efficiency and driving range. The adaptability of honeycomb panels to various manufacturing methods, including thermoforming and molding, has enabled their integration into complex automotive designs.

[0007] Honeycomb panels are used in industrial applications where structural integrity and lightweight characteristics are essential. Examples include machine components, wind turbine blades, shipping containers, and architectural panels. Honeycomb structures have also been incorporated into high-performance packaging solutions due to their excellent energy absorption and compressive strength.

[0008] In the medical field, honeycomb structures are increasingly utilized for their lightweight and shock-absorbing characteristics. Applications include orthopedic implants, wheelchair components, hospital equipment, and precision surgical instruments.

[0009] Sporting goods and outdoor product designers often utilize honeycomb panels in products like skis, snowboards, bicycle frames, foil wings, pickleball paddles, surfboard fins,Attorney Docket No. 17926-OOOOQ3-WO-POA helmets and protective gear, where weight reduction, impact resistance, engineered stiffness or compliance, and acoustics are paramount.

[0010] Despite their widespread adoption, traditional methods of manufacturing honeycomb panels often involve labor-intensive processes, high material wastage, and limitations in scalability. Furthermore, conventional honeycomb designs may suffer from performance tradeoffs such as reduced shear strength, cellular instability under compressive loads, or difficulties in customizing cell geometry (height, thickness, cross-sectional area) for specific applications.

[0011] Foam is another common panel material utilized in composite engineering, design, and manufacturing. Foam and honeycomb panels both offer distinct advantages and disadvantages when used in composite panels, making the choice of panel material application specific. Foam panels are widely favored for their ease of shaping with simple processes such as molding, sanding, cutting, or grinding to variable dimensions, such as the curved profiles of surfboards or tapered designs in recreational and industrial products. This flexibility simplifies the manufacturing process and reduces the need for post-processing. However, foam panels come with significant environmental concerns, both in their production — which often involves nonrenewable resources and emits greenhouse gases — and in disposal (scrap, dust, and waste), as many foam materials are not biodegradable or recyclable.

[0012] Additionally, foam panels generally have lower stiffness-to-weight and strength-to- weight ratios when compared to honeycomb panels, limiting their suitability for applications requiring high structural performance. Lastly, foam panel materials are typically isotropic which presents a critical opportunity to vary the density, strength, and stiffness of the panel material through the cross section.

[0013] However, honeycomb panels present unique manufacturing challenges, particularly when variable thicknesses are required across the panel. Unlike foam, which can be easily shaped or molded, honeycomb panels typically necessitate complex and costly post-processing, such as machining or adhesive bonding, to achieve variable profiles. Alternatively, advanced manufacturing techniques like additive manufacturing can address these challenges but may introduce additional costs and scalability concerns. These trade-offs highlight the need for an efficient process to create variable cell heights and dimensions for a honeycomb or lattice panel, core or layer of a stacked or composite panel assembly.Attorney Docket No. 17926-OOOOQ3-WO-POA

[0014] As designs evolve and industries continue to demand lighter, stronger, and more sustainable materials, novel manufacturing methods and improved honeycomb panel or hybrid honeycomb or lattice and foam designs are valuable to designers, engineers, and manufacturers. Advancements that address these challenges have the potential to expand the applicability of honeycomb structures across existing and emerging markets, including aerospace, automotive, medical, sporting goods, furniture, and industrial applications.

[0015] There exists a need in many applications for structures that are convex, or thicker at the center of the cross-section and tapering toward the edges to optimize strength, stiffness, and aerodynamics while minimizing weight. In addition to cambered or convex honeycomb panels and the composite panel constructions they support, there also exists a need for honeycomb structures that are cross-sectionally thicker on the perimeter than in the center. This design approach is particularly beneficial for applications that require enhanced strength, stiffness, durability, and energy absorption at their edges while supporting a specific concave surface geometry, maintaining flexibility, or reducing weight in the middle of the panel or variablethickness surface.

[0016] A significant limitation of conventional honeycomb panel manufacturing lies in the inability to efficiently produce panels or layers thereof with variable cell heights across their cross-section. Current honeycomb manufacturing processes often necessitate complex, three- dimensional, multi-axis machining, complex injection molding tools, additive manufacturing, or adhesive layering to achieve these variable height or thickness profiles, leading to increased costs, material waste, and potential structural weaknesses. Innovative and efficient methods to manufacture honeycomb panels with integrated variable cell heights can address these challenges, offering tailored solutions for high-performance and consumer product markets.SUMMARY

[0017] The present disclosure provides a significant enhancement to the manufacturing methods currently utilized to produce honeycomb or lattice structures in which the resulting cell height and subsequent panel thickness can vary across the article of manufacture. The present disclosure also supports the design configurations possible with an engineered core leveraging variable thickness layers stacked to produce variable thickness, stiffness, density, or geometryAttorney Docket No. 17926-OOOOQ3-WO-POA resulting in variable physical, structural and / or mechanical properties in a composite panel assembly.

[0018] A method of manufacturing and article of manufacture thereof is disclosed in which a honeycomb or lattice structure with variable cell height is produced using a two-dimensional (planar) cutting method applied to a honeycomb or lattice structure that is loaded and deformed against a three-dimensional tool. After the load is removed, the panel relaxes, and a variable cell height structure is realized.

[0019] The variable cell height structure can be assembled to a secondary structure or series of stacked layers along mating surface interfaces in which cells may be vertically aligned or intentionally offset throughout the cross section of the panel.

[0020] A honeycomb, structural foam or lattice structure with constant or variable (cell) height may also be stacked or combined with a natural, polymeric, or foam layer of constant or variable thickness to produce a structural core with a resultant thickness that is constant or variable. The cell structure may vary in thickness or cell size. The foam layers may vary in density, thickness, stiffness, or other material properties to vary the mass and stiffness properties across the stacked, layered or combined panel. The foam may be isotropic or anisotropic, continuous, or may have material removed in selected locations via molding or machining. Material can be removed and could be any geometry including slots, depressions, or holes through the thickness of the panel or foam material.

[0021] Considering the need for variable stiffness, strength, mass properties, and component cost of a composite panel construction, the present disclosure provides a method of manufacturing and an article of manufacture that utilizes constant or variable thickness honeycomb, lattice or foam structures in a singular or layered configuration that includes variable height across the panel or a layer thereof in support of a composite panel of variable properties. Methods for manufacturing and articles thereof that include variable thickness (height) layers can produce structural panels that are flat on both sides, convex on both sides, convex on one side and flat on the other, concave on both sides, concave on one side and flat on the other, or a combination of concave and convex surfaces are disclosed in this filing.Attorney Docket No. 17926-OOOOQ3-WO-POA

[0022] In one aspect, a honeycomb panel of variable cell height is manufactured leveraging three-dimensional tooling and two-dimensional (planar) cutting to support face sheets on each side of the core with constant or variable surface curvature that is generally not parallel across the honeycomb panel.

[0023] In another aspect of the disclosure, the dimensional height (i.e., thickness), strength, and stiffness of the honeycomb panel can vary across a span (e.g., width) of the panel. In yet another aspect of the disclosure, the panels forming a composite panel assembly can be made of different materials that have different physical and / or mechanical properties (e.g., density, stiffness).

[0024] In still a further aspect of the disclosure, two or more panels can be stacked and / or bonded together to form a composite panel assembly. In yet another aspect, the cells of one honeycomb or lattice panel of the composite panel assembly may align with, or may be intentionally offset from, the cells of an adjacent honeycomb or lattice panel of the composite panel assembly. In still another aspect, intentionally offset cells can shorten the overall height of the composite panel assembly and reduce the risk of cellular buckling under compressive loads.

[0025] In some cases, such as sport game paddles, it may be advantageous to strategically vary the material or thickness (variable) of one of these core materials or layers to decrease the bending stiffness toward the perimeter of the sport game paddle. Conversely, the opposite methodology can be used to locally increase the bending stiffness near the center of the paddle. The result can reduce the drop off in coefficient of restitution for impacts that are off-center and closer to the perimeter of the sport game paddle.

[0026] When manufacturing a panel or composite panel structure, it may be desirable to vary the material, thickness, stiffness, strength, density, or other properties of the panel structure. Combining or layering multiple materials that may be constant, or variable thickness, constant or variable density, constant or variable stiffness can accentuate changes to panel or structural thickness, stiffness, density, or geometry to produce varying properties across the structure. This could be useful where variable compliance is desired such as sports equipment (surfboards, pickleball paddles, foil wings, etc.) or aerospace applications (wings, rudders, etc.).

[0027] In some cases, a “naked” honeycomb or lattice core is manufactured and reduced to a prescribed, constant thickness with a planar cutting methodology that may include but is notAttorney Docket No. 17926-OOOOQ3-WO-POA limited to several methods, such as machining e.g., CNC machining), milling, blade cutting, die cutting, laser cutting, fly cutting, saw cutting, chemical removal, waterjet cutting, hot wire cutting, sanding and grinding. A naked honeycomb panel or core is simply the honeycomb or lattice panel or core without a textile or other top and bottom surface material bonded to the core.

[0028] The disclosure demonstrates a method to fixture and precisely deform a panel against a three-dimensional tool (e.g., concave, convex, hemispherical, ellipsoidal) allowing for a planar or two-dimensional material removal method (e.g., cutting) to remove a variable amount of material on a side of the panel. After the material is removed and the panel is removed from the fixture and tool, the panel returns to its original, undeformed shape but now has a variable thickness. This process can be repeated on a second side of the panel to create a variable, concave, or convex surface on either side or both sides of the panel.

[0029] A preferred embodiment of this disclosure utilizes a naked honeycomb core or panel material though these processes can also be used with a honeycomb panel that has layers of textile or face sheets as these can be removed by the planar cutting process.

[0030] The present disclosure may pertain to the paddles used in racquet sports, specifically paddle-ball games and sports or other engineered designs in which a variable core height or panel thickness is necessary to optimize the design of the structure or product. While pickleball and padel are exemplary applications, aspects of the disclosure apply to a wide range of engineered structures and products.

[0031] Additional features and utilities of the present disclosure will become apparent upon review and understanding of the drawings and description.DRAWINGS

[0032] These and / or other features and utilities of the present disclosure will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:Attorney Docket No. 17926-OOOOQ3-WO-POA

[0033] FIG. 1 A is a cross-sectional view of the panel of honeycomb or lattice panel taken along the line A- A of FIG. IB.

[0034] FIG. IB is a front view of the honeycomb or lattice panel.

[0035] FIG. 1C is an isometric view of honeycomb or lattice panel.

[0036] FIG. 2A is a schematic representation of a cross-sectional view of a honeycomb or lattice panel having a constant cell height.

[0037] FIG. 2B is a schematic representation of the honeycomb or lattice panel of FIG. 2A and showing a force(s) applied to a perimeter of a first side of the panel to bias or elastically deform the panel against a first positive or convex tool.

[0038] FIG. 2C schematically depicts a first planar cutting or material removal process in which material is removed from the first side of the panel of FIG. 2B.

[0039] FIG. 2D is a schematic representation of the honeycomb or lattice panel following the first process depicted in FIG. 2C and the panel is removed from the first tool and allowed to return to an unbiased or undeformed condition in which the first side of the panel now has a negative or concave surface, a second side of the panel opposite to the first side of the panel from which is material has been removed is flat, and the panel has a variable height.

[0040] FIG. 2E is a schematic representation of the honeycomb or lattice panel of FIG. 2D and showing a force(s) applied to a perimeter of the second side of the panel to bias or elastically deform the panel against a second positive or convex tool.

[0041] FIG. 2F schematically depicts a second planar cutting or material removal process in which material is removed from the second side of the panel of FIG. 2D.

[0042] FIG. 2G is a schematic representation of the honeycomb or lattice panel following the second process depicted in FIG. 2F and the panel is removed from the second tool and allowed to return to an unbiased or undeformed condition in which both the first side and the second side of the panel now have negative or concave surfaces and the panel has a variable height.Attorney Docket No. 17926-OOOOQ3-WO-POA

[0043] FIG. 3A a schematic representation of a cross-sectional view of a honeycomb or lattice panel having a constant cell height.

[0044] FIG. 3B is a schematic representation of the honeycomb or lattice panel of FIG. 3A and showing a force(s) applied to a center of a first side of the panel to bias or elastically deform the panel against a first negative or concave tool.

[0045] FIG. 3C schematically depicts a first planar cutting or material removal process in which material is removed from the first side of the panel of FIG. 3B.

[0046] FIG. 3D is a schematic representation of the honeycomb or lattice panel following the first cutting process depicted in FIG. 3C and the panel is removed from the first tool and allowed to return to an unbiased or undeformed condition in which the first side of the panel now has a positive or convex surface, a second side of the panel opposite to the first side of the panel from which is material has been removed is flat, and the panel has a variable height.

[0047] FIG. 3E is a schematic representation of the honeycomb or lattice panel of FIG. 3D and showing a force(s) applied to a center of the second side of the panel to bias or elastically deform the panel against a second negative or concave tool.

[0048] FIG. 3F schematically depicts a second planar cutting or material removal process in which material is removed from the second side of the panel of FIG. 3D.

[0049] FIG. 3G is a schematic representation of the honeycomb or lattice panel following the second process depicted in FIG. 2F and the panel is removed from the second tool and allowed to return to an unbiased or undeformed condition in which both the first side and the second side of the panel now have positive or convex surfaces and the panel has a variable height.

[0050] FIG. 4A a schematic representation of a cross-sectional view of a honeycomb or lattice panel having a constant cell height that is less than a target height of a composite panel assembly including multiple stacked panels.Attorney Docket No. 17926-OOOOQ3-WO-POA

[0051] FIG. 4B is a schematic representation of the honeycomb or lattice panel of FIG. 4A and showing a force(s) applied to a perimeter of a first side of the panel to bias or elastically deform the panel against a first positive or convex tool.

[0052] FIG. 4C schematically depicts a first planar cutting or material removal process in which material is removed from the first side of the panel of FIG. 4B.

[0053] FIG. 4D is a schematic representation of the honeycomb or lattice panel following the first process depicted in FIG. 4C and the panel is removed from the first tool and allowed to return to an unbiased or undeformed condition in which the first side of the panel now has a negative or concave surface, a second side of the panel opposite to the first side of the panel from which is material has been removed is flat, and the panel has a variable height.

[0054] FIG. 4E shows a panel assembly of two negative or concave panels of FIG.4D where the respective flat second sides of the panels are bonded to one another at a mating surface and the panel assembly has a first negative or concave surface, a second side having a second negative or concave surface and a variable height.

[0055] FIG. 4F shows a panel assembly of two negative or concave panels of FIG.4D and similar to that of FIG. 4E and in which respective cells of the bonded panels are offset from one another at the mating surface.

[0056] FIG. 5A a schematic representation of a cross-sectional view of a honeycomb or lattice panel having a constant cell height that is less than a target height of a composite panel assembly including multiple stacked panels.

[0057] FIG. 5B is a schematic representation of the honeycomb or lattice panel of FIG. 5A and showing a force(s) applied to a center of a first side of the panel to bias or elastically deform the panel against a first negative or concave tool.

[0058] FIG. 5C schematically depicts a first planar cutting or material removal process in which material is removed from the first side of the panel of FIG. 5B.Attorney Docket No. 17926-OOOOQ3-WO-POA

[0059] FIG. 5D is a schematic representation of the honeycomb or lattice panel following the first cutting process depicted in FIG. 5C and the panel is removed from the first tool and allowed to return to an unbiased or undeformed condition in which the first side of the panel now has a positive or convex surface, a second side of the panel opposite to the first side of the panel from which is material has been removed is flat, and the panel has a variable height.

[0060] FIG. 5E shows a panel assembly of two positive or convex panels of FIG. 5D where the respective flat second sides of the panels are bonded to one another at a mating surface and the panel assembly has a first positive or convex surface, a second side having a second positive or convex surface and a variable height.

[0061] FIG. 5F shows a panel assembly of two positive or convex panels of FIG. 5D and similar to that of FIG. 5E and in which respective cells of the bonded panels are offset from one another at the mating surface.

[0062] FIG. 5G shows a panel assembly of a negative or concave first panel of FIG. 4D and a positive or convex second panel of FIG. 5D bonded to one another at a mating surface and the panel assembly has a an arched shape.

[0063] FIG. 5H shows a panel assembly of a negative or concave first panel of FIG. 4D and a positive or convex second panel of FIG. 5D bonded to one another at a mating surface and the panel assembly has an arched shape like FIG. 5G and in which respective cells of the bonded panels are offset from one another at the mating surface.

[0064] FIG. 6A is a schematic representation of a cross-sectional view of a honeycomb or lattice panel having a near constant thickness and cell height, a concave first surface and a convex second surface.

[0065] FIG. 6B is a schematic representation of a cross-sectional view of a structural foam panel with first and second opposed concave surfaces and a variable thickness.

[0066] FIG. 6C is a schematic representation of a cross-sectional view of a composite panel assembly having two opposed honeycomb or lattice panels of FIG. 6A and the variable thickness structural foam panel of FIG. 6B positioned between the two opposed honeycomb orAttorney Docket No. 17926-OOOOQ3-WO-POA lattice panels and where each of the honeycomb or lattice panels is bonded at its second surface to a respective surface of the foam panel which separates the two opposed honeycomb or lattice panels.

[0067] FIG. 6D is a schematic representation of a cross-sectional view of a composite panel assembly having two opposed honeycomb or lattice panels of FIG. 6A and a variable thickness structural foam panel positioned between the two opposed honeycomb or lattice panels and separating or filling the space at the perimeter of the panel assembly and where each of the honeycomb or lattice panels is bonded at its second surface to a respective surface of the structural foam panel.

[0068] FIG. 7A is a schematic representation of a cross-sectional view of a foam panel having a near constant thickness, a concave first surface and a convex second surface.

[0069] FIG. 7B is a schematic representation of a cross-sectional view of a honeycomb or lattice panel having first and second opposed concave surfaces and a variable thickness.

[0070] FIG. 7C is a schematic representation of a cross-sectional view of a composite panel assembly having two opposed structural foam panels of FIG. 7A and the variable thickness honeycomb or lattice panel of FIG. 7B positioned between the two opposed structural foam panels and where each of the structural foam panels is bonded at its second surface to a respective surface of the honeycomb or lattice panel which separates the two opposed structural foam panels.

[0071] FIG. 7D is a schematic representation of a cross-sectional view of a composite panel assembly having two opposed structural foam panels of FIG. 7A and a variable thickness honeycomb or lattice panel or core layer positioned between the two opposed structural foam panels and separating or filling the space at the perimeter of the panel assembly and where each of the structural foam panels is bonded at its second surface to a respective surface of the honeycomb or lattice panel.

[0072] FIG. 8A is a schematic representation of a cross-sectional view of a structural foam panel having a first density and / or stiffnesss and having a near constant thickness, a concave first surface and a convex second surface.Attorney Docket No. 17926-OOOOQ3-WO-POA

[0073] FIG. 8B is a schematic representation of a cross-sectional view of a foam panel having a second density and / or stiffness and first and second opposed concave surfaces and a variable thickness.

[0074] FIG. 8C is a schematic representation of a cross-sectional view of a composite panel assembly having two opposed structural foam panels of FIG. 8A and the variable thickness foam panel of FIG. 8B positioned between the two opposed structural foam panels and where each of the structural foam panels is bonded at its second surface to a respective surface of the foam panel which separates the two opposed structural foam panels.

[0075] FIG. 8D is a schematic representation of a cross-sectional view of a composite panel assembly having two opposed structural foam panels of FIG. 8A and a variable thickness structural foam panel or core layer positioned between the two opposed structural foam panels and separating or filling the space at the perimeter of the panel assembly and where each of the structural foam panels is bonded at its second surface to a respective surface of the honeycomb or lattice panel.

[0076] FIG. 9A is a schematic representation of a cross-sectional view of a honeycomb or lattice panel having a variable thickness, a first flat surface and second convex surface.

[0077] FIG. 9B is a schematic representation of a cross-sectional view of a structural foam panel having first and second opposed concave surfaces and a variable thickness.

[0078] FIG. 9C a schematic representation of a cross-sectional view of a composite panel assembly having two honeycomb or lattice panels of FIG. 9A and a variable thickness structural foam panel of FIG. 9B positioned between two honeycomb or lattice panels and where each of the honeycomb or lattice panels is bonded at its second surface to a respective surface of the structural foam panel.

[0079] FIG. 9D is a schematic representation of a cross-sectional view of a composite panel assembly having two opposed honeycomb or lattice panels of FIG. 9A and a variable thickness foam or core panel positioned between the two opposed honeycomb or lattice panels and separating or filling the space at the perimeter of the panel assembly and where each of theAttorney Docket No. 17926-OOOOQ3-WO-POA honeycomb or lattice panels is bonded at its second surface to a respective surface of the core panel.

[0080] FIG. 10A is a schematic representation of a cross-sectional view of a foam panel having a variable thickness, a first flat surface and second convex surface.

[0081] FIG. 10B is a schematic representation of a cross-sectional view of a honeycomb or lattice panel having first and second opposed concave surfaces and a variable thickness.

[0082] FIG. 10C a schematic representation of a cross-sectional view of a composite panel assembly having two opposed foam panels of FIG. 10A and a honeycomb or lattice panel of FIG. 10B positioned between the two opposed foam panels and where each of the foam panels is bonded at its second surface to a respective surface of the honeycomb or lattice panel.

[0083] FIG. 10D is a schematic representation of a cross-sectional view of a composite panel assembly having two opposed foam panels of FIG. 10A and a variable thickness honeycomb or lattice panel or core layer positioned between the two opposed foam panels and separating or filling the space at the perimeter of the panel assembly and where each of the foam panels is bonded at its second surface to a respective surface of the honeycomb or lattice panel.

[0084] FIG. 11 A is a schematic representation of a cross-sectional view of a foam panel having first density and / or stiffness, a variable thickness, a first flat surface and second convex surface.

[0085] FIG. 1 IB is a schematic representation of a cross-sectional view of a foam panel having a second density and / or stiffness and first and second opposed concave surfaces and a variable thickness.

[0086] FIG. 11C is a schematic representation of a cross-sectional view of a composite panel assembly having two opposed foam panels of FIG. 11 A and the foam panel of FIG. 1 IB positioned between the two opposed foam panels of FIG. 11 A and where each of the foam panels of FIG. 11 A is bonded at its second surface to a respective surface of the foam panel of FIG. 11B which separates the two opposed foam panels of FIG. 11 A.Attorney Docket No. 17926-OOOOQ3-WO-POA

[0087] FIG. 1 ID is a schematic representation of a cross-sectional view of a composite panel assembly having two opposed foam panels of FIG. 11 A and a variable thickness foam panel or core layer positioned between the two opposed foam panels of FIG. 11 A and separating or filling the space at the perimeter of the panel assembly and where each of the foam panels of FIG. 11 A is bonded at its second surface to a respective surface of the core layer.

[0088] FIG. 12 depicts a general stress distribution through a central section of a panel with a bending load applied and showing the largest stress observed at the top (compressive, o, b, c) and bottom of the panel (tensile, o b, t) with stress decreasing to zero at the neutral axis.

[0089] FIGs. 13A - 13E show an exemplary panel portion of sport game paddle where FIG. 13A is a cross-sectional view taken along line 13A-13A of FIG. 13D; FIG. 13B is a cross-sectional view taken along line 13B-13B of FIG. 13D; FIG. 13C is a cross-sectional view taken along line 13C-13C of FIG. 13D; FIG. 13D is a front view of the panel portion; and FIG. 13E is an isometric view of the panel portion.

[0090] FIGs. 14A-14F show schematic representations of cross-sectional views of various other exemplary composite panel assemblies according to the present disclosure.

[0091] Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements. The figures are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Furthermore, the drawings provide examples and / or implementations consistent with the description; however, the description is not limited to the examples and / or implementations provided in the drawings.DESCRIPTION

[0092] Reference will now be made in detail to the one or more exemplary embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present disclosure while referring to the figures. Also, while describing the present disclosure, detailed descriptions of related well-known functions or configurations that may diminish the clarity of the points of the present disclosure may be omitted.Attorney Docket No. 17926-OOOOQ3-WO-POA

[0093] The present disclosure is directed to panels and panel assemblies and methods for manufacturing the panels and panel assemblies. The panels and panel assemblies of the disclosure can comprise a single panel or stacked (composite) arrangement of multiple panels. The panels of the present disclosure may be of constant or variable thickness, flat on one or both sides (i.e., the top and bottom), convex on one or both sides, convex on one side and flat on the other side, concave on one or both sides, concave on one side and flat on the other side, concave on one side and convex on the other side, or any other combination of constant or variable thickness, flat constant thickness, curved constant thickness, and curved variable thickness. The process for manufacturing a panel disclosed may utilize tooling having a three-dimensional working surface and employ a two-dimensional (e.g., planar) material removal (e.g., cutting) process. It should be understood and appreciated that the three-dimensional working surface of the tooling can comprise one or more surfaces having different dimensional characteristics (e.g., radii or planes) in or along different directions or axes, and can include one or more curved surfaces, planar surfaces and / or combinations thereof.

[0094] FIGs. 1A to 1C show views of an exemplary panel of honeycomb material 100 that has been cut to the shape of a pickleball paddle head. FIG. IB is a top view of the panel 100, FIG. 1C is an isometric view of the panel 100 and FIG. 1A is a cross-sectional view of the panel 100 taken along the line A- A of FIG. IB. The honeycomb panel 100 has a perimeter 101 with a cell height of 103. The honeycomb or lattice panel 100 that may be employed according to this disclosure may take any shape and may have a constant cell height 103 or the cell height may be variable through modification according to this disclosure or other manufacturing processes.

[0095] A method for manufacturing a panel having a variable cross-sectional thickness in at least a portion of a span (e.g., width) of the panel is shown in FIGs. 2A-2E. FIG. 2A is a simplified cross-sectional view of a honeycomb or lattice panel 200 with a constant cell height 203. FIG. 2B is a schematic of the honeycomb panel 200 of FIG. 2A in which force(s) F2 are applied at the perimeter 201 of the panel 200 to elastically deform or bend the honeycomb or lattice panel 200 against a first positive or convex tool 210. The force(s) F2 applied can be result from fixturing, clamping, pressure, point loads, or other methods of applying force(s) to the perimeter 201 of the honeycomb panel 200. FIG. 2C schematically depicts a planar cutting or material removal process 220 in which a first portion of material 212 is removed from the panel 200 inside of the forces F2 applied to the perimeter 201 as shown in FIG. 2B. Planar cutting methods contemplated by this disclosure may include but are not limited to: CNC operations,Attorney Docket No. 17926-OOOOQ3-WO-POA blade cutting, die cutting, laser cutting, fly cutting, saw cutting, chemical removal, waterjet cutting, sanding, grinding, or hot wire cutting. FIG. 2D shows the honeycomb panel 200' after it has been cut according to the material removal process 220 illustrated in FIG. 2C, removed from the tool 210 and allowed to relax or rebound to a pre-elastically-deformed condition. The resulting panel 200' includes a negative or concave surface 205, a variable height cross-section 203' and a flat surface 207 (i.e., the uncut side of the panel).

[0096] Additional manufacturing steps can further modify the panel 200'. FIG. 2E represents an optional secondary process step in which the honeycomb panel 200' is flipped and loaded into a second, positive or convex tool 210' and forces F2' are applied to the perimeter 201' to prepare the panel 200' for a subsequent or secondary cutting process 220'. If symmetry in the panel 200' is desired, the second tool 210' will have a radius R2' that is approximately half of the radius R2 of the first positive or convex tool 210. FIG. 2F depicts the secondary planar cutting or material removal process 220' in which a secondary portion of material 212' is removed from the honeycomb or lattice panel 200' inside of the forces F2' applied to the perimeter 201'as shown in FIG. 2E. FIG. 2G shows the panel of honeycomb material 200" following the secondary cutting process 220' shown in FIG. 2F, being removed from the tool 210' and allowed to relax or rebound to a pre-elastically-deformed condition. The resulting panel 200" includes two negative or concave surfaces 205", 207" and a variable height cross-section 203".

[0097] An alternative manufacturing method is shown in FIGs. 3A-3G. FIG. 3A shows a simplified cross-sectional view of a honeycomb or lattice panel 300 with constant cell height 303. FIG. 3B is a schematic of the honeycomb panel 300 of FIG. 3A in which force(s) F3 are applied to the center 301 of the panel to elastically deform or bend the honeycomb panel 300 against a first, negative or concave tool 310. FIG. 3C depicts a planar cutting or material removal process 320 in which a first portion of material 312 is removed from the panel 300 outside of the force(s) F3 applied to the center 301 of the panel 300 as shown in FIG. 3B. This process 320 may or may not differ from the planar cutting or material removal process 220 as the removal accounts for the clamping or pressure applied to the center 301 of the honeycomb panel 300 against the first negative, or concave tool 310. FIG. 3D is a view of the honeycomb panel 300' after it has been cut according to the material removal process 320 illustrated in FIG. 3C, removed from the tool 310 and allowed to relax or rebound to a pre-elastically-deformed condition. The resulting panel 300' includes a positive or convex surface 305', a variable height cross-section 303' and a flat surface 307' (i.e., the uncut side of the panel 300').Attorney Docket No. 17926-OOOOQ3-WO-POA

[0098] FIG. 3E represents yet another optional process step 320' in which the honeycomb panel 300' from FIG. 3D is flipped and loaded into a second, negative or concave tool 310' and force(s) F3' are applied to the center 301' to prepare the panel 300 for a cutting process 320'. If symmetry is desired, the second tool 312 will have a radius R3' that is approximately half of the radius R3 of the first positive or convex tool 310. FIG. 3F depicts a secondary planar cutting or material removal process 320' in which a secondary portion of material 312' is removed from the honeycomb or lattice panel 300' inside of the forces F3'applied to the center 301' as shown in FIG. 3E. FIG. 3G shows the panel honeycomb material 300" following the secondary cutting process 320' shown in FIG. 3F, being removed from the tool 310' and allowed to relax or rebound to a pre-elastically-deformed condition. The resulting panel 300" includes two positive or convex surfaces 305", 307" and a variable height cross-section 303".

[0099] With reference to FIGs. 4A-4F, a method for manufacturing a composite panel assembly is shown. FIG. 4A provides a cross-sectional view of a honeycomb or lattice panel 400 with constant cell height 403 that is less than the total target height H4 of a multiple panel, composite panel assembly 400", 400'" (see, FIGs. 4E, 4F). FIG. 4B is a schematic of the honeycomb panel 400 of FIG. 4A in which force(s) F4 are applied to the perimeter 40 Ito elastically deform or bend the honeycomb panel 400 against a positive or convex tool 410. The force(s) F4 applied can result from fixturing, clamping, pressure, point loads, or other methods of applying force to the perimeter 401 of the honeycomb panel 400. FIG. 4C depicts a planar cutting or material removal process 420 in which a first portion of material 412 is removed from the panel 400 inside of the force(s) F4 applied to the perimeter 401 as shown in FIG. 4B. Planar material removal methods contemplated by this disclosure may include but are not limited to CNC machining, milling, blade cutting, die cutting, laser cutting, fly cutting, saw cutting, chemical removal, waterjet cutting, sanding, grinding, or hot wire cutting. FIG. 4D is a view of the honeycomb panel 410' after it has been cut according to the material removal process 420 illustrated in FIG. 4C, removed from the tool 410 and allowed to relax or rebound to a pre- elastically-deformed condition. The resulting panel 400' includes a negative or concave surface 405', a variable height cross-section 403' and a flat surface 407' (i.e., the uncut side of the panel 400').

[0100] FIG. 4E shows a composite panel assembly 400" including two (2) negative or concave panels 400' (as shown in FIG.4D) stacked and / or bonded at an interface 430' of respective flatAttorney Docket No. 17926-OOOOQ3-WO-POA surfaces 407'. The panel assembly 400" has a variable height cross-section H4. FIG. 4F shows a different composite panel assembly 400'" including two (2) negative or concave panels 400' (as shown in FIG.4D) stacked and / or bonded at an interface 430'" of respective flat or mating surfaces 407'. The first panel 400' is stacked and / or bonded to the second panel 400' in a manner in which the individual cells 415'" of the respective first and second panels 400' are offset from one another at the mating surface interface 430'". The panel assembly 400'" has a variable height cross-section H4.

[0101] FIGs. 5A-5H show another manufacturing process and additional composite panel assemblies. FIG. 5A is a cross-sectional view of a honeycomb or lattice panel 500 with constant cell height 503 that is less than the total target height H5 of a multiple panel, panel assembly 500", 500'" (FIGs. 5G, 5H). FIG. 5B is a schematic of the honeycomb panel 500 of FIG. 5A in which force(s) F5 are applied to a center 501 to elastically deform or bend the honeycomb panel 500 against a negative or concave tool 510. The force(s) F5 applied can result from fixturing, clamping, pressure, point loads, or other methods of applying force to the perimeter 501 of the honeycomb panel 500. FIG. 5C depicts a planar cutting or material removal process 520 in which a first portion of material 512 is removed from the panel 500 outside of the force(s) applied to the center 501 as shown in FIG. 5B. Planar cutting methods contemplated by this disclosure may include but are not limited to: CNC operations, blade cutting, die cutting, laser cutting, fly cutting, saw cutting, chemical removal, waterjet cutting, sanding, grinding, or hot wire cutting. FIG. 5D is a view of the honeycomb panel 500' in FIG. 5C after it has been cut according to the material removal process 520 illustrated in FIG. 5C, removed from the tool 510 and allowed to relax or rebound to a pre-elastically-deformed condition. The resulting panel 500' includes a positive or convex surface 505', a variable height cross-section 503' and a flat surface 507' (i.e., the uncut side of the panel 500').

[0102] FIGs. 5E-5H depict various composite panel assemblies. FIG. 5E shows a panel assembly 500" having two (2) positive or convex panels 500' (as shown in FIG.5D) stacked and / or bonded at an interface 530' of respective flat or mating surfaces 507'. The panel assembly 500" has a variable height cross-section H5. FIG. 5F shows a panel assembly 500'" having two (2) positive or convex panels 500' (as shown in FIG.5D) stacked and / or bonded at an interface 530"'of respective flat or mating surfaces 507'. The first panel 500' is stacked and / or bonded to the second panel 500' in a manner in which the cells 515'" of the respective first and second panels 500' are offset from one another at the mating surface interface 530'". The panelAttorney Docket No. 17926-OOOOQ3-WO-POA assembly 500'" has a variable height cross-section H5. FIG. 5G shows a panel assembly 550 including a negative or concave panel 400' and a positive or convex panel 500' (as shown in FIG. 4D and FIG. 5D) stacked and / or bonded to one another at an interface 580 the respective flat or mating surfaces 407' and 507' to produce a panel assembly 550 having an arched shape. FIG. 5H shows a panel assembly 550' including a negative or concave panel 400' and a positive or convex panel 500' stacked and / or bonded at an interface 580'of respective flat or surfaces 407' and 507'. The first panel 500' is stacked and / or bonded to the second panel 400' in a manner in which the cells 565' of the respective first and second panels 500' and 400' are offset from one another at the mating surface interface 580'. The resulting panel assembly 550' has an arched shape.

[0103] Referring to FIGs. 6A-6D, FIG. 6A shows a cross-sectional view of a honeycomb or lattice panel 600 of near constant thickness and cell height 603 and having one concave surface 605 and one convex surface 607 after manufacturing or bending loads applied during manufacturing. FIG. 6B shows a variable thickness 611 structural foam panel 602 with concave surfaces 604, 606 on both sides of the panel 602 after molding, machining or compression during manufacturing. FIG. 6C depicts a concave, stacked panel assembly 608 with two opposing honeycomb or lattice panels 600 of near constant thickness, and one concave surface 605 and one convex surface 607 surrounding the variable thickness structural foam panel 602 which provides a core layer separating or filling space between the panels 600, including at the center 601 of the panel assembly 608. A bonding interface 630 may exist between each of the panels 600 and the foam panel core layer 602. FIG. 6D shows a concave, stacked panel assembly 610 with two opposing honeycomb or lattice panels 600 of near constant thickness, one concave surface 605 and one convex surface 607 surrounding a variable thickness structural foam panel 609 which provides a core layer separating or filling the space between the panels600 on the perimeter of the panel assembly 610. In this case, the foam panel core layer 609 may not be present or in continuous contact with the honeycomb or lattice surfaces 607 in the center601 of the panel. A bonding interface 630 may exist between each of the panels 600 and the foam panel core layer 609.

[0104] Turning to FIGs. 7A-7D, FIG. 7A shows a foam panel 700 of near constant thickness 703, one concave surface 705 and one convex surface 707 that may be preformed or loaded in bending during manufacturing to create an arched curvature. FIG. 7B shows a variable thickness 711 honeycomb or lattice panel 702. The foam panel 702 can include concave surfaces 704, 706Attorney Docket No. 17926-OOOOQ3-WO-POA on both sides of the panel 702. FIG. 7C depicts a concave, stacked panel assembly 708 with two opposing near constant thickness structural foam panels 700 surrounding a variable thickness honeycomb or lattice panel 702 which provides a core layer separating or filling the space between the panels 700, including at the center 701 of the panel assembly 708. A bonding interface 730 may exist between each of the panels 700 and the core layer 702 at respective mating surfaces 707, 704, 706. FIG. 7D shows a concave, stacked panel assembly 710 having two opposed near constant thickness structural foam panels 700 surrounding a variable thickness honeycomb or lattice structure 709 which provides a core layer separating or filling the space between the panels 700 on the perimeter of the panel assembly 710. In this case, the honeycomb or lattice core layer 709 may not be present or in continuous contact with mating surfaces 707 of the top and bottom foam panels 700 surfaces in the center of the panel assembly 710. A bonding interface 730 may exist between the each of the panels 700 and the honeycomb or lattice core layer 709.

[0105] Another alternative composite panel assembly can be understood with reference to FIGs. 8A-8D. FIG. 8A shows a foam panel 800 of near constant thickness 803, one concave surface 805 and one convex surface 807 and having a density DO and / or stiffness SO. The panel 800 may be preformed or loaded in bending during manufacturing to create the curvature in the panel 800. FIG. 8B shows a variable thickness 811 structural foam panel 802 of a different density D2 and / or stiffness S2 than the density DO and / or stiffness SO of the foam panel 800 of FIG. 8A. The foam panel 802 can include concave surfaces 804, 806 on both sides of the panel 802 after molding, machining or compression during manufacturing. FIG. 8C depicts a concave, stacked panel assembly 808 including opposing structural foam panels 800 of near constant thickness 803, one concave surface 805 and one convex surface 807 surrounding a foam panel 802 which provides a core layer of the panel assembly 808. The panel assembly 808 has a different density D2 and / or stiffness S2 in the core layer than the density DO and / or stiffness SO in the surrounding foam layers 800 forming the top and bottom of the stacked panel assembly 808. A bonding interface 830 may exist between each of the panels 800 and the foam panel core layer 802 at respective mating surfaces 807, 804, 806. FIG. 8D shows a concave, stacked panel assembly 810 with two opposing structural foam layers 800 of near constant thickness 803, one concave surface 805 and one convex surface 807 surrounding a variable thickness foam layer 809 which provides a core layer separating or filling the space between the panels 800 on the perimeter of the panel assembly 810. In this case, the foam layer 809 may not be present or in continuous contact with mating surfaces 807 of the foam panels 800 in the center 801 of theAttorney Docket No. 17926-OOOOQ3-WO-POA panel assembly 810. A bonding interface 830 may exist between each of the panels 800 and the foam panel core layer 809.

[0106] Turning to FIGs. 9A-9D, FIG. 9A shows a cross-sectional view of a honeycomb or lattice panel 900 of variable thickness and cell height 903 and having one convex surface 905 and one flat surface 907 after manufacturing (such as described in FIGs. 3A-3D). FIG. 9B shows a variable thickness 911 structural foam panel 902 with concave surfaces 904, 906 on both sides of the panel 902 after molding, machining or compression during manufacturing. FIG. 9C depicts a stacked panel assembly 908 having two opposed honeycomb or lattice panels 900 of variable thickness 903, one flat surface 905 and one convex surface 907 surrounding a variable thickness structural foam panel 902 which provides a core layer separating or filling the space between the panels 900, including at the center 901of the panel assembly 908. A bonding interface 930 may exist between mating surfaces 907 each of the panels 900 and the foam panel core layer 902 at respective mating surfaces 907, 904, 906. FIG. 9D shows a stacked panel assembly 910 having two opposed honeycomb or lattice panels 900 of variable thickness 903, one flat surface 905 and one convex surface 907 surrounding a variable thickness foam panel 902 which provides a core layer separating or filling the space between the panels 900. In this case, the foam core layer 902 may not be present or in continuous contact with mating surfaces 907 of each of the panels 900 in the center 901 of the panel assembly 910. A bonding interface 930 may exist between each of the panels 900 and the foam panel core layer 909.

[0107] Another alternative embodiment of a composite panel assembly of the present disclosure is understood from FIGs. 10A-10D. In FIG. 10A, a foam panel 1000 of variable thickness 1003, one flat surface 1005 and one convex surface 1007 that may be molded or machined to shape is shown. FIG. 10B shows a variable thickness 1011 honeycomb or lattice panel 1002 with concave surfaces 1004, 1006 on both sides of the panel 1002 (such as described at FIGs. 2A- 2G). FIG. 10C depicts a stacked panel assembly 1008 with two opposed foam panels 1000 of variable thickness 1003, one flat surface 1005 and one convex surface 1007 that may be molded or machined to shape surrounding a concave, variable thickness honeycomb or lattice panel 1002 which provides a core layer separating or filling the space between the panels 1000, including at the center lOOlof the stacked panel assembly 1008. A bonding interface 1030 may exist between each of the panels 1000 and the honeycomb panel core layer 1002 at respective mating surfaces 1007, 1004, 1006. FIG. 10D shows a stacked panel assembly 1010 having two opposing foam panels 1000 of variable thickness 1003 surrounding a variable thicknessAttorney Docket No. 17926-OOOOQ3-WO-POA honeycomb or lattice structure 1009 which provides a core layer separating or filling the space between the panels 1000. In this case, the honeycomb or lattice core layer 1009 may not be present or in continuous contact with mating surfaces 1007 of each of the panels 1000 in the center of the panel assembly 1010. A bonding interface 1030 may exist between each of the panels 1000 and the honeycomb core layer 1009.

[0108] FIG.s 11A-11D illustrate still another composite panel assembly embodiment of the present disclosure. FIG. 11A shows a foam panel 1100 of variable thickness 1103 and having a density Dl l and / or stiffness Si l, one flat surface 1105 and one convex surface 1107 that may be molded or machined to shape. FIG. 1 IB shows a variable thickness 1111 structural foam panel 1102 and having a different density D12 and / or stiffness S12 than the density Dl l and / or stiffness SI lof the foam panel 1100 of FIG. 11A. The foam panel 1102 can include concave surfaces 1104, 1106 on both sides of the panel 1102 after molding, machining or compression during manufacturing. FIG. 11C depicts a stacked panel assembly 1108 having two opposing foam panels 1100 of variable thickness 1103, one flat surface 1105 and one convex surface 1107 that may be molded or machined to shape surrounding a structural foam panel 1102 variable thickness 1111 having a different density D12 and / or stiffness S12 than the density Dl l and / or stiffness SI 1 of the foam panel 1100 of FIG. 11A which provides a core layer separating or filling the space between the panels 1100 including at the center 1101 of the panel assembly 1108. A bonding interface 1130 may exist between each of the panels 1100 and the foam panel core layer 1102 at respective mating surfaces 1107, 1004, 1006. FIG. 1 ID is a stacked panel assembly 1110 having two opposing foam panels 1100 of variable thickness 1103, one flat surface 1105 and one convex surface 1107 that may be molded or machined to shape surrounding a structural foam panel 1109 having a different density D13 and / or stiffness S13 than the density Dl l and / or stiffness SI lof the foam panel 1100 of FIG. 11A which provides a core layer separating or filling the space between the panels 1100. In this case, the core layer 1109 may not be present or in continuous contact with mating surfaces 1107 of each of the panels 1100 in the center of the panel assembly 1110. A bonding interface 1130 may exist between each of the panels 1100 and the foam core layer 1109.

[0109] FIG. 12 provides a visual representation of a general stress distribution through a central section of a panel with a bending load applied and showing the largest stress observed at the top of the panel (compressive, o, b, c) and the bottom of the panel (tensile, o b, t) with stress decreasing to zero at the neutral axis of the panel.Attorney Docket No. 17926-OOOOQ3-WO-POA

[0110] FIGs. 13A - 13E show an exemplary panel portion of sport game paddle where FIG. 13A is a cross-sectional view taken along line 13A-13A of FIG. 13D; FIG. 13B is a cross-sectional view taken along line 13B-13B of FIG. 13D; FIG. 13C is a cross-sectional view taken along line 13C-13C of FIG. 13D; FIG. 13D is a front view of the panel portion; and FIG. 13E is an isometric view of the panel portion. A perimeter foam layer surrounds a core layer. In addition, holes, slots, or large sections of material are introduced, removed or substituted without diverging from the local constructions disclosed. The sections along lines A-A, B-B and C-C can define planes in which a curvature of the panel or core layer can be measured.

[0111] One example of a method according to the present disclosure for selectively removing material from one side of a panel having a structure comprising a plurality of cells (e.g., a honeycomb or lattice) to produce a concave (or negative) profile (e.g., a panel that is thinner near the center than at the perimeter) is described with reference to FIGs. 2A-2G, as follows:

[0112] 1. Select a panel (length, width, thickness, cell size, cell wall thickness, cell shape, etc.) and / or cut a panel to the desired size and profile, e.g., as shown in FIGs. IB and 1C. FIGs. 2A, 3A, 4A, and 5A are representative of the cross-section of a panel as shown in FIG. 1A. to perform subsequent operations, it may be helpful to have extra material or tabs to clamp or hold the panel. FIG. 1B-1C show a typical honeycomb core for a pickleball paddle, though the present disclosure is not so limited.

[0113] 2. Fixture the panel in a tool with a second side of the panel facing or adjacent to a three- dimensional working surface of the tool (e.g., a tool having a working surface that has a positive or a convex profile as shown in FIG. 2B).

[0114] 3. Apply a force or pressure to the panel to cause the panel to elastically deform and conform to the three-dimensional working surface of the tool.

[0115] 4. While the panel is fixtured and deformed against the three-dimensional working surface of the tool, utilize a two-dimensional or planar material removal process to remove a selected amount of material from a central portion of the first side of the panel (e.g., inside of the fixtured edges of the panel) as depicted in FIG. 2C. Material removal processes may include, butAttorney Docket No. 17926-OOOOQ3-WO-POA are not limited to: machining, milling, blade cutting, die cutting, laser cutting, fly cutting, saw cutting, chemical removal, waterjet cutting, hot wire cutting, sanding, and grinding.

[0116] 5. Remove the panel from the tool and allow the panel to return to its non-elastically- deformed condition. The cells of the panel will be shorter (i.e., the panel thickness is thinner) in the center of the panel than at the perimeter of the panel creating a negative or concave profile panel as shown in FIG. 2D.

[0117] 6. Optionally, the method may be repeated on the second side as shown in FIGs. 2E and 2F. Note, however, that if symmetric material removal is required for both sides as shown in FIG. 2G, then a tool having a different three-dimensional working surface is necessary for the second side of the panel in order to compensate for the material already removed from the first side of the panel in the previous steps.

[0118] 6. Additional panels, textile and / or face sheets can be joined and / or applied to one or both surfaces of the panel, as modified.

[0119] Another example of a method according to the present disclosure for selectively removing material from one side of a panel having a structure comprising a plurality of cells (e.g., a honeycomb or lattice) to produce a convex (or positive) profile (e.g., a panel that is thicker near the center than at the perimeter) is similar to the method just described and is understood with reference to FIGs. 3A-3G.

[0120] In other exemplary embodiments of the present disclosure, the panels with variable cell height created by one of the previous processes are stacked and bonded to create a composite panel assembly as shown in FIGs. 4E, 4F, 5E, 5F, 5G, 5H, 6C, 6D, 7C, 7D, 8C, 8D, 9C, 9D, 10C, 10D, 11C, and 1 ID. Two panels can be bonded on planar or mating surfaces to create an assembled composite panel. A critical advantage of this assembly process is that cells can be aligned as shown in FIGs. 4E, 5E, and 5G, or intentionally misaligned as shown in FIGs. 4F, and 5F. An interesting result of intentional misalignment is the fact that the resulting cell walls are shorter in height and less likely to buckle under compressive load as there is balanced support from the mating honeycomb panel. In stacked composite panel assemblies in which multiple honeycomb, lattice structures, or foam materials are used, the physical, mechanical and / or material properties of the individual panels as well as the composite panel assembly can varyAttorney Docket No. 17926-OOOOQ3-WO-POA through the cross-section and across the surface to change the dynamic response of the composite panel to meet the goals of the design. FIGs. 14A-14F show schematic representations of cross-sectional views of various additional exemplary composite panel assemblies 1402, 1404, 1406, 1408, 1410, 1412 according to the present disclosure.

[0121] The processes of the present disclosure can also be used to efficiently stack honeycomb or lattice panels of variable cell height to in various combinations to produce more complex composite panel surfaces and shapes. For example, with reference to FIGs. 5G and 5H (offset cells), a convex panel (top) is attached or bonded to a concave panel (bottom) at their respective flat surfaces to produce a resulting composite panel assembly that has an arch-shaped curvature. Alternatively, two or more individual panels can be bonded on mating curved surfaces to create composite assemblies having complex curvatures and geometries with varying cell wall heights.

[0122] The panel constructions and composite panel assemblies of the present disclosure may find uses in applications including, but not limited to:

[0123] Aerospace

[0124] Airplane Wings: Variable thickness profiles to accommodate airfoil profiles, fuel tanks, and structural loads.

[0125] Fuselage Panels: Adjusted honeycomb core height for localized strength, stiffness, and reduced weight.

[0126] Helicopter Rotor Blades: Tapered cores for aerodynamic performance and vibration reduction.

[0127] Radomes: Thinner centers and reinforced edges for structural integrity and signal clarity.

[0128] Automotive

[0129] Car Doors and Dashboards: Enhanced crash protection at edges with lightweight central sections.Attorney Docket No. 17926-OOOOQ3-WO-POA

[0130] Vehicle Floors: Structural reinforcement at load-bearing edges.

[0131] Electric Vehicle Battery Packs: Tailored cores to accommodate battery placement and cooling systems.

[0132] Hood and Trunk Panels: Impact-resistant perimeters with weight-saving central cores.

[0133] Marine

[0134] Surfboard and Paddleboard Cores: Thicker centers for buoyancy and stiffness with thinner edges for turning and weight reduction. In some surfboard designs, the top surface may be convex, while the bottom surface is concave.

[0135] Hydrofoils: Aerodynamic airfoil profiles with thicker center sections to create lift.

[0136] Boat Decks and Hulls: Variable thickness structural cores optimized for strength-to- weight ratios.

[0137] Sporting Goods

[0138] Bicycle Frames: Custom honeycomb core heights for stiffness in high-stress areas and engineered flexibility in others.

[0139] Helmets: Impact absorption with engineered honeycomb core dimensions and customize geometry fit to the user.

[0140] Snowboards and Skis: Variable profile sections to control flexibility or surface profile.

[0141] Pickleball paddles or Padel Rackets: Internal support of concave striking surfaces to improve performance of off-center impacts.Attorney Docket No. 17926-OOOOQ3-WO-POA

[0142] Medical

[0143] Prosthetics: Variable cell heights for load-bearing perimeters and comfort-focused interiors.

[0144] Industrial and Construction

[0145] Shipping Containers: Reinforced edges to handle loading stresses.

[0146] Wind Turbine Blades: Tapered profiles for aerodynamics and load optimization.

[0147] Architectural Panels: Enhanced perimeters for structural stability, and thinner centers for reduced weight.

[0148] Consumer Goods

[0149] Furniture: Chairs, tables, and shelves with load-bearing edges and lightweight central cores.

[0150] Protective Packaging: Corner and edge reinforcement for impact absorption.

[0151] Appliances: Lightweight, durable panels for refrigerators, ovens, and washing machines.

[0152] Drones: Lightweight but strong cores for aerodynamic body structures and propeller blades.

[0153] Electronics: Honeycomb cooling panels for laptops or server racks with varying thicknesses for airflow optimization.

[0154] High-Performance Luggage and Coolers: Impact-resistant edges and lightweight central cores.Attorney Docket No. 17926-OOOOQ3-WO-POA

[0155] For purposes of this disclosure, the term “honeycomb” should also be considered to represent alternative “lattice” structures of varying geometry in support of an engineered panel or structure.

[0156] References to height and thickness herein may be understood in context and can refer to a cross-sectional dimension of a panel, panel component (e.g., cell), or panel assembly. The terms positive or convex describe a profile that has greater cell heights in the center than the perimeter of the honeycomb, lattice, polymer, composite or foam, panel, core or layer and may or may not be continuously positive or convex. The terms negative or concave describe a profile that has shorter cell heights in the center than the perimeter of the honeycomb, lattice, polymer, composite or foam, panel, core or layer and may or may not be continuously negative or concave. The terms “first” and “second” as used herein to describe various elements may be used simple to distinguish one from another of a plurality of the same type structure or component, or of different structures or components.

[0157] Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements. The figures are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Furthermore, the drawings provide examples and / or implementations consistent with the description; however, the description is not limited to the examples and / or implementations provided in the drawings.

Claims

Attorney Docket No. 17926-OOOOQ3-WO-POACLAIMSWhat is claimed is:

1. A method for manufacturing a panel having a variable cross-sectional thickness over at least a portion of the panel, the method comprising: providing a panel wherein the panel comprises a structure comprising a plurality of cells, and wherein each of the plurality of cells extends from a first side of the panel to a second side of the panel; providing a tool comprising a working surface; engaging the tool with the panel by applying the working surface of the tool to the second side of the panel and elastically deforming the panel from a relaxed condition to a deformed condition conforming to the working surface of the tool; removing a portion of the panel at the first side of the panel with a planar material removal process; and disengaging the tool from the panel and allowing the panel to return to the relaxed condition.

2. The method according to claim 1, wherein the working surface is curved.

3. The method according to claim 1, wherein the working surface comprises a three- dimensional curvature.

4. The method according to claim 1, wherein the working surface comprises a convex curvature.

5. The method according to claim 1, wherein the working surface comprises a concave curvature.

6. The method according to claim 1, wherein the working surface is hemispherical.

7. The method according to claim 1, wherein the working surface is ellipsoidal.

8. The method according to claim 1, wherein the working surface is polygonal.Attorney Docket No. 17926-OOOOQ3-WO-POA9. The method according to claim 1, wherein the panel comprises one of a honeycomb structure and a lattice structure.

10. The method according to claim 1, wherein the planar material removal process comprises one of machining, milling, blade cutting, die cutting, laser cutting, fly cutting, saw cutting, chemical removal, waterjet cutting, hot wire cutting, sanding and grinding.

11. The method according to claim 1, further comprising: engaging the tool with the panel by applying the working surface of the tool to the first side of the panel and elastically deforming the panel from the relaxed condition to a second deformed condition conforming to the working surface of the tool; removing a second portion of the panel at the second side of the panel with a second planar material removal process; and disengaging the tool from the panel and allowing the panel to return to the relaxed condition.

12. The method according to claim 1, wherein the tool comprises a second working surface; and further comprising: engaging the tool with the panel by applying the second working surface of the tool to the first side of the panel and elastically deforming the panel from the relaxed condition to a second deformed condition conforming to the second working surface of the tool; removing a second portion of the panel at the second side of the panel with a second planar material removal process; disengaging the tool from the panel and allowing the panel to return to the relaxed condition.

13. The method according to claim 1, further comprising: providing a second tool comprising a second working surface; engaging the second tool with the panel by applying the second working surface of the second tool to the first side of the panel and elastically deforming the panel from the relaxed condition to a second deformed condition conforming to the second working surface of the tool; removing a second portion of the panel at the second side of the panel with a second planar material removal process; andAttorney Docket No. 17926-OOOOQ3-WO-POA disengaging the second tool from the panel and allowing the panel to return to the relaxed condition.

14. The method according to claim 13, wherein the working surface and the second working surface each comprise a convex curvature.

15. The method according to claim 13, wherein the working surface and the second working surface each comprise a concave curvature.

16. The method according to claim 13, wherein the working surface comprises a convex curvature and the second working surface comprises a concave curvature.

17. A composite panel assembly comprising: a first panel according to claim 4; a second panel according to claim 4; wherein the second side of the first panel is attached to the second side of the second panel.

18. The composite panel assembly of claim 17, wherein the plurality of cells of the first panel are vertically aligned with the plurality cells of the second panel.

19. The composite panel assembly of claim 17, wherein the plurality of cells of the first panel are vertically offset from the plurality cells of the second panel.

20. A composite panel assembly comprising: a first panel according to claim 5; a second panel according to claim 5; wherein the second side of the first panel is attached to the second side of the second panel.

21. The composite panel assembly of claim 20, wherein the plurality of cells of the first panel are vertically aligned with the plurality cells of the second panel.Attorney Docket No. 17926-OOOOQ3-WO-POA22. The composite panel assembly of claim 20, wherein the plurality of cells of the first panel are vertically offset from the plurality cells of the second panel.

23. A composite panel assembly comprising: a first panel according to claim 4; a second panel according to claim 5; wherein the second side of the first panel is attached to the second side of the second panel.

24. The composite panel assembly of claim 23, wherein the plurality of cells of the first panel are vertically aligned with the plurality cells of the second panel.

25. The composite panel assembly of claim 23, wherein the plurality of cells of the first panel are vertically offset from the plurality cells of the second panel.

26. A composite panel assembly comprising: a first panel according to claim 16; a second panel according to claim 16; a third panel comprising a foam material and having a first concave side and a second concave side; and wherein the second side of the first panel is attached to the first side of the third panel and the second side of the second panel is attached to the second side of the third panel.

27. The composite panel assembly of claim 26 wherein the first panel, the second panel and the third panel are stacked vertically; wherein the composite panel assembly comprises a central vertical axis; and wherein third panel comprises an opening around the central vertical axis.

28. A composite panel assembly comprising: a first panel comprising a first foam material and having a first side and a second convex side; a second panel comprising a second foam material and having a first side and a second convex side; a third panel according to claim 14; andAttorney Docket No. 17926-OOOOQ3-WO-POA wherein the second convex side of the first panel is attached to the first side of the third panel and the second convex side of the second panel is attached to the second side of the third panel.

29. The composite panel assembly of claim 28 wherein the first side of the first panel is flat and the first side of the second panel is flat.

30. The composite panel assembly of claim 28 wherein the first side of the first panel is concave and the first side of the second panel is concave.

31. The composite panel assembly of claim 28 wherein the first side of the first panel is concvex and the first side of the second panel is convex.

32. The composite panel assembly of claim 28 wherein the first panel, the second panel and the third panel are stacked vertically; wherein the composite panel assembly comprises a central vertical axis; and wherein third panel comprises an opening around the central vertical axis.

33. A composite panel assembly comprising: a first panel according to claim 5; a second panel according to claim 5; a third panel comprising a foam material and having a first concave side and a second concave side; and wherein the second side of the first panel is attached to the first side of the third panel and the second side of the second panel is attached to the second side of the third panel.

34. The composite panel assembly of claim 33 wherein the first panel, the second panel and the third panel are stacked vertically; wherein the composite panel assembly comprises a central vertical axis; and wherein third panel comprises an opening around the central vertical axis.

35. A composite panel assembly comprising: a first panel comprising a first foam material and having a first side and a second convex side;Attorney Docket No. 17926-OOOOQ3-WO-POA a second panel comprising a second foam material and having a first side and a second convex side; a third panel comprising a third foam material and having a first concave side and a second concave side; and wherein the second convex side of the first panel is attached to the first side of the third panel and the second convex side of the second panel is attached to the second convex side of the third panel.

36. The composite panel assembly of claim 35 wherein the first side of the first panel is flat and the first side of the second panel is flat.

37. The composite panel assembly of claim 35 wherein the first side of the first panel is convex and the first side of the second panel is convex.

38. The composite panel assembly of claim 35 wherein the first side of the first panel is concave and the first side of the second panel is concave.

39. The composite panel assembly of claim 35 wherein the first panel, the second panel and the third panel are stacked vertically; wherein the composite panel assembly comprises a central vertical axis; and wherein third panel comprises an opening around the central vertical axis.

40. The composite panel assembly of claim 35 wherein at least one of a first density and a first stiffness of the first panel and at least one of a second density and a second stiffness of the second panel are each different from at least one of a third density and a third stiffness of the third panel.

41. A composite panel assembly comprising: a first panel according to claim 5; a second panel according to claim 5; a third panel comprising a foam material; wherein the second side of the first panel is attached to the first side of the third panel and the second side of the second panel is attached to the second side of the third panel.Attorney Docket No. 17926-OOOOQ3-WO-POA42. A composite panel assembly comprising: a first panel according to claim 16; a second panel according to claim 16; a third panel according to claim 15; and wherein the first side of the first panel is attached to the first side of the third panel and the first side of the second panel is attached to the second side of the third panel.

43. A composite panel assembly comprising: a first panel comprising a first foam material and having a first concave side and a second convex side; a second panel comprising a second foam material and having a first concave side and a second convex side; a third panel according to claim 15; and wherein the first concave side of the first panel is attached to the first side of the third panel and the first concave side of the second panel is attached to the second side of the third panel.

44. A composite panel assembly comprising: a first panel comprising a first foam material and having a first convex side and a second flat side; a second panel comprising a second foam material and having a first convex side and a second flat side; a third panel comprising a first side and a second side opposite the first side, wherein the third panel comprises a structure comprising a plurality of cells, and wherein each of the plurality of cells has a first height; and wherein the second flat side of the first panel is attached to the first side of the third panel and the second flat side of the second panel is attached to the second side of the third panel.

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