Abstract:
The present invention may comprise methods of fabricating a paddle with monolithic fiber composite parts. The invention may result in an integral piece, while minimizing weaknesses and manufacturing complexity. Superior paddles are produced that avoid dead spots, soft spots, laminar separation, and other disadvantages while retaining consistent rigidity and improving play during pickleball play.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority from U.S. Provisional Patent Application No. 62/065,579, filed on Oct. 17, 2014, the contents of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates generally to paddles for sports, and in particular, to pickleball paddles. Pickleball paddles are sometimes referred to as pickleball rackets, pickleball racquets, bats, or other terms. 
         [0003]    Pickleball is played on a badminton-sized court with a net. The ball is a perforated plastic hollow ball (similar to a Wiffle Ball™) which is struck by players using a paddle visually resembling large table tennis paddles. Pickleball paddles may be made from wood, graphite, aluminum, composite materials, and other materials. 
         [0004]    Pickleball paddles are usually constructed by cutting or machining a large sheet of material (called a panel) into the shape of a paddle. Another option is molding foam material into the shape of a paddle. The handle area is then built up with a spacer, upon which grip tape and an end cap are applied. Various types of edge treatments are usually applied around the perimeter of the paddle for a finished look and to provide protection against damage. 
         [0005]    Pickleball paddles were originally made from a solid sheet of wood or plywood, but the heavy weight, warping issues, and poor quality appearance made an alternative material necessary. Although some paddles are still made from wood, a composite material has made pickleball paddles much more lightweight without decreasing rigidity. Such composite paddles are now made from a composite material that includes a skin and a core. 
         [0006]    The USA Pickleball Association (USAPA, usapa.org) is the national governing agency for pickleball. Pickleball paddle manufacturers provide the USAPA with their paddles to test and approve them for use in tournaments. The USAPA requires pickleball paddles to be rigid (very little flex), flat, non-abrasive and within a particular size (height and width) range. The USAPA does not require or suggest any specific materials or manufacturing techniques. 
         [0007]    It is known that a pickleball paddle usually comprises a striking head or blade, which is generally flat with a rounded contour for striking the ball, and a handle to which the striking head is attached. Typically, the paddle material, striking head and handle contain both a core and a skin. The skin is sometimes called a “laminate” or “face sheet.” When the core material is bonded to the skin material it is usually called a “composite panel” or “sandwich panel.” 
         [0008]    A sandwich-structured composite is a special class of composite materials that is fabricated by attaching two thin, but stiff, skins to a lightweight, but thick, core. The core material is normally low strength material, but its greater thickness provides the sandwiched composite with both high bending stiffness and low overall density. 
         [0009]    Open-cell-structures and closed-cell-structured foams like polyvinylchloride, polyurethane, polyethylene or polystyrene foams, balsa wood, syntactic foams, and honeycombs are commonly used core materials. Open-cell and closed-cell metal foam can also be used as core materials. 
         [0010]    Laminates of glass or carbon fiber-reinforced thermoplastics or thermoset polymers (unsaturated polyesters, epoxies, and such) are widely used as skin materials. Sheet metal is also used as skin material in some cases. 
         [0011]    The core is usually, but not always, made from foam, plastic, aramid, aluminum, honeycomb or a combination thereof. The blade is covered, on at least one side and generally on both sides, with a skin, such as fiberglass, carbon fiber, aluminum, wood, plastic or graphite. 
         [0012]    Typical paddles develop weak spots or soft spots, known as “dead spots” at locations where wear damage occurs, or where the adhesive fails, resulting in delamination of the face material from the core material. 
         [0013]    An additional problem with the current design of paddles made from sandwich panels arises as a result of the edge treatments. Some manufacturers apply a u-channel or other type of molding to protect the edge and enclose the gap created by the core. This creates the problem of interference when striking the ball in this area of the paddle. Some manufacturers finish the edge with a composite material. This renders the edge of the paddle overly fragile, resulting in damage if the ground or a hard object is struck during play. All previous methods of finishing the edge of the paddle have created reliability issues, as the edge treatment tends to become loose and separate or fall off with age or stress. 
         [0014]    Thus, it would be advantageous to have a paddle that did not require an edge treatment. This would require the paddle to be made out of a solid material so that the hollow or honeycomb core is not visible on the edges. It would be further advantageous for this solid material to be strong enough to withstand hitting the ground or other objects without suffering damage. 
         [0015]    A lightweight, rigid, and solid material without a “skin” would be further advantageous instead of the sandwich panel, as it would serve to prevent “dead spots.” Embodiments exist for manufacturing pickleball paddles from composite materials in a sandwiched configuration. 
         [0016]    These various devices are cumbersome in use and construction. It would be advantageous to provide a pickleball paddle that would include one or more of the features of 1) lightweight, but of sturdy construction; 2) no delamination issues; 3) responds to striking a ball with a powerful response; and 4) requires minimal edge treatments. 
       SUMMARY OF THE INVENTION 
       [0017]    In one aspect of the present invention, a paddle for a game, comprising; a substantially planar member, the substantially planar member sufficiently rigid to strike a ball, and a handle attached to the substantially planar member, wherein the substantially planar member is composed of a composite material, such as a high-density, polyurethane panel impregnated with fiberglass fibers. The composite material may be continuous-strand fiberglass fibers, woven roving fiberglass fibers, or a combination of the two, or any other suitable composite material. The substantially planar member and the handle may be composed of one integral piece. The substantially planar member and the handle may both be substantially within the same plane or both not substantially within the same plane. The handle and/or the substantially planar member may be composed of a composite material. The substantially planar member may be of any suitable shape, such as rectangular, triangular, trapezoidal, or other useful shape. The substantially planar member may be symmetrical or skewed. 
         [0018]    In another aspect of the present invention, a paddle for a game may comprise; a substantially planar member, the substantially planar member sufficiently rigid to strike a ball and comprising a core and a covering fitted onto the core; and a handle attached to the substantially planar member, wherein the substantially planar member is composed of a closed-cell composite material and the covering is formed from a layer of elastomer. 
         [0019]    These and other aspects, objects, features and advantages of the present invention, are specifically set forth in, or will become apparent from, the following detailed description of an exemplary embodiment of the invention when read in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is a plan view of a paddle, according to an embodiment of the present invention; 
           [0021]      FIG. 2  is a plan view of a paddle, according to another embodiment of the present invention; 
           [0022]      FIG. 3  is a sectional view along line A-A of the paddle in  FIG. 2 , according to yet another embodiment of the present invention; and 
           [0023]      FIG. 4  is a cross-sectional view of layers in the paddle in  FIG. 3 , according to still another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0024]    The following detailed description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims. 
         [0025]    Although the invention is often referred to herein as a pickleball paddle, it is understood that such description is not limiting, such that the technology in this invention may be applied in numerous other products, including but not limited to table tennis paddles, platform tennis paddles, or other similar paddles that require a durable striking head. In general, the order of the steps of disclosed processes may be altered within the scope of the invention. It should be understood that a paddle of the present invention may be used from material cut into a paddle shape, material (such as a foam material) molded into a paddle shape, or other suitable methods of manufacture. 
         [0026]    The processes described herein constitute a means of fabricating a paddle in such a way as to eliminate the most common potential areas of the finished product&#39;s failure, by eliminating the requirement to assemble dissimilar materials by means of a mechanical process. The invention in effect creates an integral piece, without the inherent weakness and increased manufacturing complexity inherent in a process in which multiple elements are assembled. The invention applies state-of-the-art materials and processes to an existing product type, thereby enhancing production efficiency, while at the same time improving product performance and eliminating the most common causes of product failure. 
         [0027]      FIG. 1  shows a paddle  100  made from composite material. A substantially planar member  102  (also known as a blade, head, or other names) may be attached at a neck  104  to a handle  106 . The handle  106  may be covered with a grip  108 , which may be secured to the neck  104  with a binding  110 . An endcap  112  may be placed at an end of the handle  106  for support and protection of the paddle  100 . 
         [0028]      FIG. 2  illustrates a paddle  200  according to another embodiment of the present invention. The paddle may comprise a substantially planar member  202  that is a unitary piece comprising a neck  204  and a handle  206 . A grip (for example, as shown in  FIG. 1 ) may be applied to the handle  206 . 
         [0029]      FIG. 3  is a view in section on broken line A-A of  FIG. 2 . Optionally, one or more portions of the paddle  200 , such as the planar member or the handle, may be composed of a core and a covering. An exemplary display of various layers is shown in  FIG. 4 . The body of the paddle  400  may comprise a composite core  402  and one or more covering layers  404 ,  406 . 
         [0030]    A pickleball paddle may be constructed of a rigid core, a rigid foam bonded to the rigid core after solidification of the rigid foam from a liquid state, and a handle composed of the rigid core. 
         [0031]    A high-density polyurethane foam, polymer, or plastic may be reinforced with layers of fiberglass, carbon fiber, Kevlar, or any other rigid material that can reinforce the foam material that surrounds and is integrated with the core. 
         [0032]    A liquid foam, polymer or plastic may be poured over or otherwise applied to woven, rigid fibers such that the foam later solidifies after intimate contact with the woven, rigid fibers, resulting in a one-piece durable material that does not require a skin to be bonded to the material. 
         [0033]    A foamed molded item, such as a core, may be used to improve responsiveness and make for a lightweight paddle by using fiber-reinforced synthetic resin for a high mechanical strength. 
         [0034]    A core material, a covering material, and an optional skin may comprise a fiber-reinforced resin matrix resin such that reinforcing fibers are impregnated which may be arranged on both sides of the core material containing reinforcing fibers in the range of reinforcing fiber tensile modulus in the surface material may be within the range of 30-850 GPa with 40 Gpa one option. The reinforcing fiber content in the surface skin material may be in the range of 40 to 80 weight percent (wt %) while other suitable weight percentages may be used. The core material being less dense than a resin skin material and an optional fiber-reinforced plastic sandwich panel may have overall thickness in the range of 0.5-20 mm, often within the range of 3-20 mm. The present invention may be practiced without a sandwich panel arrangement. 
         [0035]    A method for producing a fiber-reinforced composite of the present invention may comprise using a mold cavity filled with expandable resin particles. On the surface of the particle packing bodies may be formed by filling the cavity, impregnating a thermosetting resin in an uncured multi-layer body forming step of forming a laminate fiber reinforcement by supplying a heating medium into the mold cavity, the thermosetting resin of the uncured heating. The expandable resin particles may be heated to be foamed as well as molding a foamed item, a molding step of deforming the fiber reinforcement along a cavity inner surface shape by blowing gas onto expandable resin particles. A curing step may be applied to the surface of the foamed molding of the fiber-reinforced material by curing the thermosetting resin of the fiber reinforcement. 
         [0036]    The fiber-reinforced composite synthetic resin may comprise expandable resin particles. Other materials may be used in the production method of the present invention, but not particularly limited to, for example, polycarbonate resins, acrylic resins, thermoplastic polyester resins, and polymethacrylic imide resin. 
         [0037]    These and other aspects, objects, features and advantages of the present invention are specifically set forth in, or will become apparent from, the description herein of an exemplary embodiment of the invention. 
         [0038]    The foregoing description is of the best currently contemplated modes of implementing the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention. 
         [0039]    It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention, and that modifications may be made without departing from the spirit and scope of the invention. 
         [0040]    Furthermore, a method may be performed in one or more sequences other than the sequence presented expressly herein. 
         [0041]    This material can be turned into a pickleball paddle by machining the shape of the pickleball paddle from a single sheet of material or molding the material info the shape of a pickleball paddle. The solid material can be rounded on the edges for a better appearance. 
         [0042]    Examples of this material are products such as “coosa panels” (available from Coosa Composites, LLC, located at 105 Pardue Road, Pelham, Ala. 35124, U.S.A.); “Thermo-Lite Boards” (closed cell composite manufactured with cross-linked polymer foam and fiberglass available from SpaceAge Synthetics, Ltd., located at 1402 39 th  Street NW, Fargo, N. Dak. 58102, U.S.A.); Airex® PXw closed-cell fiber-reinforced sheet of structural foam available from Baltek, Inc. located at 5240 National Center Drive, Colfax, N.C. 27235, U.S.A., a subsidiary of 3A Composites) and 3M™ Reinforced Polyurethane Foam (available from 3M Company, Industrial Adhesives and Tapes Division, located at 3M Center, Building 225-3S-06, St. Paul, Minn. 55144-1000, U.S.A.). 
         [0043]    Application of the process and technology described herein may result in a product that can be more efficiently produced, that is more aesthetically pleasing, that provides greater consistency of function, and more reliable than products produced using other technologies. 
         [0044]    It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims. Furthermore, a method herein described may be performed in one or more sequences other than the sequence presented expressly herein.