Traditionally, shafts for arrows and other sporting goods were made from wood, bamboo, and/or reeds. To decrease their weight and produce, for example, arrows that are easier to shoot and that can fly farther, and golf clubs that are easier to swing, modern arrows, golf clubs, and other sporting goods are made from aluminum and carbon fiber reinforced plastic. Carbon fiber, a type of fiber reinforced plastic, has been used since the 1990s as a lightweight material used to make arrows and other sporting goods. While modern materials are lighter in weight than traditional materials, modern materials are not as durable.
Various embodiments of the present invention provide improved shafts that can be used in a number of different applications, for example, for various sporting goods, such as, but not limited to, archery arrows, arrow shafts, crossbow bolts, archery bow stabilizers, golf shafts, golf clubs, and rifle barrels. In particular, embodiments of the present invention relate to adding a reinforcing layer to improve the performance of sporting goods shafts.
In some embodiments, the invention provides a hollow golf club shaft, comprising: a plurality of fiber-reinforced resin layers; and one or more reinforcing layers comprising a woven metal mesh, each reinforcing layer spanning a circumference of the golf club shaft, wherein the woven metal mesh comprises stainless steel, nickel, titanium, copper, aluminum, magnesium, or an alloy thereof, and wherein the woven metal mesh has at least 150×150 wires per square inch.
In some embodiments, the invention provides a method of manufacturing a reinforced shaft for a golf club, comprising: wrapping a plurality of fiber-reinforced resin layers around a mandrel; and wrapping one or more reinforcing layers around at least one of the plurality of fiber-reinforced resin layers, wherein the reinforcing layer(s) comprise a woven metal mesh and span a circumference of the golf club shaft, wherein the woven metal mesh comprises stainless steel, nickel, titanium, copper, aluminum, magnesium, or an alloy thereof, and wherein the woven metal mesh has at least 150×150 wires per square inch.
In some embodiments, the reinforcing layer(s) are located in the butt section of the golf club shaft, the mid section of the golf club shaft, or the tip section of the golf club shaft.
In some embodiments, the reinforcing layer(s) extend along the full length of the golf shaft.
In some embodiments, the woven metal mesh is positioned on the golf club shaft at a zero- and ninety-degree wire orientation, where the zero-degree wires are in line with a longitudinal axis of the golf shaft, and the ninety-degree wires are oriented perpendicular thereto.
In some embodiments, the woven metal mesh comprises wire having a diameter of about 0.001 inches to about 0.008 inches.
In some embodiments, the woven metal mesh comprises wire having a diameter less than or equal to 0.001 inches.
In some embodiments, the woven metal mesh has a plain weave, Dutch weave, twilled weave, twilled Dutch weave, reverse Dutch weave, or five heddle weave.
In some embodiments, the woven metal mesh is impregnated with a resin.
In some embodiments, the woven metal mesh is annealed.
In some embodiments, at least one of the plurality of fiber-reinforced resin layers comprises a carbon fiber.
Additional features and advantages of the present invention are described further below. This summary section is meant merely to illustrate certain features of the invention, and is not meant to limit the scope of the invention in any way. The failure to discuss a specific feature or embodiment of the invention, or the inclusion of one or more features in this summary section, should not be construed to limit the invention as claimed.
The foregoing summary, as well as the following detailed description of certain embodiments of the application, will be better understood when read in conjunction with the appended drawings. For the purposes of illustrating the devices and methods of the present application, there are shown in the drawings preferred embodiments. It should be understood, however, that the application is not limited to the precise arrangements and instrumentalities shown. In the drawings:
Modern arrows are typically made from a carbon fiber arrow shaft that is hollow, and include an arrow tip in the front of the arrow shaft, a nock in the rear of the arrow shaft, and fletching along the surface of the arrow shaft adjacent the nock. In flight, the hollow arrow shaft flexes slightly along its length in an oscillatory motion. Specifically, the action of shooting the arrow from the bow creates a deflection along the length of the arrow, which oscillates as the arrow travels. As a result, archers generally choose the arrow shaft and its components to match their equipment and to meet their shooting requirements. This includes choosing an arrow shaft having the correct length, weight, and stiffness. Archers chose an arrow shaft with a defined static spine, which is the stiffness of the arrow shaft and its resistance to bending. Based on their chosen arrow shaft and corresponding static spine, they then add tips, fletching, and knocks to tune the dynamic spine, which is the deflection of the arrow when fired from a bow. The physical properties of the arrow shaft, including the overall weight and the center of gravity of the arrow, affect the arrow's performance.
For a specific arrow shaft having a particular length and static spine, the change in weight will adversely affect the static spine of the arrow shaft. The static spine of an arrow shaft is generally determined by the material of the arrow shaft, the thickness of the arrow shaft walls, and the length of the arrow shaft. Changing weight between arrow shafts made of the same carbon fiber material with the same length requires changing the wall thickness of the arrow shaft. The thinner walled arrows shafts will be lighter, but will have a lower static spine because the stiffness of the arrow shaft would decrease. Altering any one of the properties of the arrow shaft will affect the other. This limits the ability of the archer to choose a particular carbon fiber arrow shaft having a specific weight, length, and diameter with a specific static spine.
Some arrows are constructed entirely out of aluminum or are constructed out of a hybrid aluminum and carbon composite. Arrows constructed out of a hybrid aluminum and carbon composite are generally made from an aluminum shaft and carbon that is either wrapped on the outside of the aluminum tube or molded to the inside of the aluminum tube. These arrows exhibit permanent deformation when launched and extracted from a target because of the low yield strength of aluminum. This results in a change in straightness of an arrow after repeated shooting or even after its initial shooting. The straightness of an arrow has a direct impact on the accuracy of the arrow. This creates a condition for a bent arrow that significantly reduces the accuracy of the arrow.
In some embodiments, the invention provides a lightweight, high-strength shaft with a reinforcing layer. The reinforced shaft is constructed of multiple layers. In some embodiments, two different materials are used to form the reinforced shaft: a carbon fiber material and a mesh material (e.g., comprising a metal such as stainless steel). The carbon fiber material and/or the mesh material may be provided as a “pre-preg” (i.e., pre-impregnated with a resin).
In some embodiments, the invention provides a shaft comprising a longitudinal axis, an inside diameter spanning the longitudinal axis, an outside diameter spanning the longitudinal axis, and a reinforcing layer. The shaft can be manufactured from fiber reinforced plastic, such as carbon fiber, or other materials generally known and used in the sporting goods industries. The reinforcing layer may be a mesh material. The reinforcing layer increases strength, such as hoop and compressive strength, speed, durability, and dynamic response.
In some embodiments, the invention provides a lightweight shaft having an overall stiffness comparable to the stiffness of a heavier shaft. In some embodiments, the invention provides a shaft having a smaller outer diameter. In some embodiments, the invention provides a thin walled shaft having an overall stiffness comparable to a thicker walled shaft.
Referring initially to
In some embodiments, the reinforcing layer 150 is a sheet of metal mesh with 80×80 wires per square inch and a wire diameter of 0.001-0.002 inches. In an illustrative embodiment, the reinforcing layer 150 is a stainless steel mesh. The pattern of the steel mesh is a plain weave where the warp wire (wire running parallel to the length of the mesh material) passes alternately over and under the wires running traversely through the mesh material (fill or shoot wires) at 90 degree angles. The reinforcing layer 150 is oriented such that the warp wire is parallel with the length of the carbon fiber blank 100 and the fill wire is perpendicular with the length of the carbon fiber blank 100, or vice versa. By orienting the mesh in this particular manner, the reinforcing layer provides additional hoop strength to the carbon fiber blank 100. It is contemplated that the angle of the mesh wires may be varied according to application and desired overall strength of the reinforced shaft 10. It is further contemplated that the number of wires per inch and wire diameter may be changed to fit the strength characteristics desired for the reinforced shaft 10. The type of metal used for the metal mesh is not meant to be limiting and the determination of type of metal used may be determined by the strength characteristics desired for the reinforced shaft 10. It is also contemplated that the reinforcing layer 150 may be made of alternative types of materials instead of, or in addition to, metal.
Referring now to
Referring now to
The mesh can be manufactured in any way known to a person having skill in the art. The mesh can be any type of mesh, including, but not limited to, fabric filter cloths. The mesh can be a woven or knitted mesh and can have any weave or knit known to a person having skill in the art. Non-limiting examples of such weaves include plain weave, regular weave, twill weave, flat tow weave, plain Dutch weave, and reverse Dutch weave. In some embodiments, the mesh is woven with a plain weave, Dutch weave, twilled weave, twilled Dutch weave, reverse Dutch weave, or five heddle weave.
The mesh can be made from any material known to a person having skill in the art.
Non-limiting examples of the materials that can be used for the mesh include aluminum, steel, stainless steel, brass, titanium, neodymium magnetized wire, nickel, silver, a synthetic fiber, such as nylon or poly-paraphenylene terephthalamide, or any combination or alloy thereof. A person having skill in the art would know to use any material, or a combination or alloy thereof, to achieve a desired ultimate tensile strength and/or yield strength. In some embodiments, the alloy used is nitinol.
The mesh can be modified from as low as 20 mesh to up to 500 mesh. A person having skill in the art would modify the mesh to achieve a preferred density for the arrow, golf club, rifle barrel, etc. A person having skill in the art can adjust the mesh from one end of the shaft to the other to tune the shaft. Modifying the number of wires per inch as well as varying the wire diameters in the warp and weft directions can achieve preferable results, such as faster arrow recovery, deeper penetration greater stored kinetic energy, increased structural durability, as well as changing the front of center balance of the arrow.
In some embodiments of the invention, the mesh material is a woven 304 stainless steel, with 200 mesh (0.002 inch thick wire×0.002 inch thick wire). In other embodiments, the mesh material is a Dutch weave using 0.0032 inch (0.0813 mm) thick wire×0.0018 inch (0.04572 mm) thick wire, in which the 0.0032 inch wire is in the warp direction, which runs parallel along the longitudinal length of the tube, and the 0.0018 inch wire will be the weft which will wrap around the tube.
Referring now to
For some embodiments of the present invention, a side view of the manufacturing method shows the use of mandrel 190 with diameter 192 wrapped with carbon fiber material 120. After applying the carbon fiber material 120 around the mandrel 190, the reinforcing layer 150 is applied around the carbon fiber material 120. The diameter 192 of the mandrel 190 forms the interior diameter 14 of the reinforced shaft 10 and the amount of carbon fiber material 120 wrapped around the mandrel 190 in conjunction with the thickness of the reinforcing layer 150 forms the exterior diameter 12 of the reinforced shaft 10. After curing the carbon fiber material 120 wrapped with the reinforcing layer 150, the mandrel 190 is removed in direction 194 leaving a reinforced shaft 10 with a carbon fiber blank 100 with a reinforcing layer 150. The carbon fiber blank 100 with reinforcing layer 150 is finished into the reinforced shaft 10.
The carbon fiber material 120 can be made by molding fiber reinforced plastic, pultruding carbon fiber, or casting or extruding a metal, such as aluminum. One non-limiting type of carbon fiber is “pre-preg,” which is a carbon fiber material pre-impregnated with a resin. The carbon fiber material 120 can be formed from any material known to those of skill in that art. The carbon fiber material 120 can also be formed by shaping fiber reinforced plastic, carbon fiber, or extruding aluminum around a mandrel.
The reinforcing layer 150 can be fiber reinforced plastic, pultruding carbon fiber, or casting or extruding a metal sleeve, such as aluminum. The reinforcing layer 150 can be formed from any material known to those of skill in the art. The material used for the reinforcing layer 150 can be the same as, or different from, the material used to form the carbon fiber material 120. By way of non-limiting example, the carbon fiber material 120 can be made of a metal, such as aluminum, and the reinforcing layer 150 can be made of a fiber reinforced plastic, such as carbon fiber; the carbon fiber material 120 can be made of a fiber reinforced plastic, such as carbon fiber, and the reinforcing layer 150 can be made of a metal, such as aluminum; the carbon fiber material 120 and the reinforcing layer 150 can both be made of a fiber reinforced plastic; or the carbon fiber material 120 and the reinforcing layer 150 can both be made of a metal.
The reinforcing layer 150 can be part of the construction of the carbon fiber material 120. The reinforcing layer 150 can be part of the carbon fiber material 120 or it can be added or layered under or over the carbon fiber material 120, or in any layer or any successive layer that surrounds the carbon fiber material 120. The reinforcing layer 150 can be used on all or only a portion of the shaft. Different reinforcing layers 150 or meshes may be used in or on the shaft. Multiple reinforcing layers 150 may be oriented at the same or different angles in or on the shaft. In some embodiments, the reinforcing layer 150 is a layer that spans the longitudinal axis of the shaft. In some embodiments, the reinforcing layer 150 is part of the carbon fiber material 120 of the shaft. In some embodiments, the reinforcing layer 150 is part of the outer diameter of the shaft. In some embodiments, the reinforcing layer 150 is a layer of the shaft. In some embodiments, the reinforcing layer 150 is on an arc or other portion of the shaft. In some embodiments, the reinforcing layer 150 spans the entire shaft.
In some embodiments of the invention, a reinforced arrow shaft is made in accordance with the following steps. Pre-preg, 304 stainless steel woven mesh, and glass scrim are arranged on a mandrel so that the pre-preg layer is in contact with the mandrel and the glass scrim is the layer farthest from the mandrel. Cello wrapping is applied to outside of the glass scrim layer using a horizontal cello wrapping machine. After the cello is wrapped around the outside of the pre-preg, stainless steel mesh, and glass scrim, the combined layers are placed in an oven with the mandrel to fully cure. Once cured, the shaft is removed from the oven. The outer cello wrapping is removed and/or stripped away from the shaft. The mandrel is then removed from the inside of the shaft. The shaft is then ground to the appropriate spine and outside diameter. Only the top layer of the glass scrim material will be ground making sure that there is no contact between the grinder and the stainless steel mesh.
In some embodiments, the reinforcing layer 150 may comprise a heavier metal mesh material. In some embodiments, the heavier mesh may be, for example, 304 stainless steel wire mesh, 80 mesh×120 mesh, 0.05 mm×0.05 mm. In other embodiments, the heavier mesh may be, for example, 304 stainless steel in a 150×150 mesh using a 0.0024 inch (0.06096 mm) diameter wire. In some embodiments, the heavier metal mesh may use another type of stainless steel (such as, but not limited to, 316L stainless steel) or other metal/alloy as described above.
In some embodiments, the reinforcing layer 150 may comprise a feather-weight metal mesh material. The feather-weight metal mesh material may have, for example, at least 150×150 wires per square inch (150 mesh) and a wire gauge (diameter) of 0.001 inches (0.0254 mm) or less. The feather-weight metal mesh material may be made from stainless steel, such as, but not limited to, 304 stainless steel or 316L stainless steel, or other metal/alloy as described above, and can have any weave (e.g., plain weave, Dutch weave, twilled weave, twilled Dutch weave, reverse Dutch weave, five heddle weave), such as, but not limited to, a standard or Dutch weave. In some embodiments, the feather-weight metal mesh material has a standard weave, and can be oriented at different angles.
The metal mesh material (304 or 316L stainless steel or other metal/alloy) used for the reinforcing layer 150 may be non-annealed or annealed. Annealing is a heat treatment process that can make the wires in the weave softer and malleable. During this process, a roll of mesh is exposed to extremely high heat (while staying well below the melting point of the metal) and pressure. Annealing wire mesh reduces the internal stress and hardness of the weave, which can make it easier to form, for example, over an arrow or golf mandrel. In some embodiments, a reinforcing layer 150 comprising a metal mesh made from annealed stainless steel can be more malleable and easier to roll onto sporting goods shafts such as arrow shafts and golf shafts, as compared to mesh made from non-annealed metal.
In some embodiments, the reinforcing layer 150 may be provided as a “pre-preg” wherein the mesh material (e.g., woven metal mesh) is pre-impregnated with a catalyzed resin (e.g., epoxy). Similar to embodiments of the carbon fiber pre-preg described above, during the impregnation process, a fiber or woven substrate (e.g., woven metal mesh) is sandwiched between two films consisting essentially of resin. The resin films and the substrate material that is between the two films is then subjected to heat and high pressure which spreads the substrate reinforcement and forces the resin into the substrate. Once the resin has impregnated the substrate thoroughly, the carrier paper that one of the resin films is applied to is removed and the prepreg is slit to an exact width and rolled onto a final cardboard core. The pre-preg material is then cut into precise patterns and rolled onto a mandrel and cured. Once the material has been cured, the tube is extracted from the mandrel yielding a composite tubular structure.
In some embodiments, the reinforcing layer 150 may comprise a pre-preg material formed as shown schematically in
In some embodiments of the invention, a reinforced shaft for a rifle barrel may be provided, which can overcome certain barriers in making carbon fiber rifle barrels. In existing carbon fiber rifles, shooting heats up the resin in the carbon fiber composite material, which can have deleterious effects, for example, on the barrel straightness. Metal particles (e.g., iron particles) can be added to the resin used to form the carbon fiber composite to provide a heat path; however, this addition weakens the resin substantially. In contrast, when a woven metal mesh layer according to embodiments of the present invention (e.g., reinforcing layer 150 as described above) is incorporated on a stainless steel rifle barrel, it can act as a continuous heat sink in the composite; the heat being generated and transferred into the composite is thus more uniform, which can eliminate softening of the resin and provide a more accurate rifle.
A reinforced shaft for a rifle barrel according to various embodiments of the invention may be made by a method comprising rolling at least one reinforcing layer around a steel rifle barrel, and rolling at least one carbon fiber layer around the reinforcing layer(s). In some embodiments, the reinforcing layer comprises at least one metal mesh pre-preg layer as described above in connection with reinforcing layer 150, and the carbon fiber layer comprises a carbon fiber composite material such as carbon fiber material 120. The metal mesh pre-preg reinforcing layer(s) can act as a thermal conductor of heat away from the steel portion of the rifle barrel, and can also act as a heat conductor from the chamber end directed toward the muzzle end of the rifle barrel. The metal mesh wire can provide, for example, about 15 times the thermal conductivity of a non-reinforced carbon fiber structure. In some embodiments, the metal mesh wire may comprise a metal that holds a magnetic charge (e.g., neodymium) and can provide an integral magnetic field inside the composite structure. The metal mesh wire can absorb the heat from a rifle being fired, and can reduce the amount of heat transferred to the surrounding composite material. The metal mesh wire can reduce the amount of heat in the surrounding resin system of the composite material (thus acting as a heat sink). The metal mesh wire can allow the composite rifle barrel to maintain its straightness and accuracy by reducing the softening effect on the composite when undergoing rapid firing. The metal mesh wire adds significant strength and stiffness to a rifle barrel compared to other methods of minimizing heat effects on a composite barrel, such as adding metal particles to the epoxy resin in the composite itself.
In some embodiments, as shown in
In some embodiments, the invention provides a reinforced shaft for a rifle barrel, comprising: at least one reinforcing layer positioned around the outer surface of a steel rifle barrel between a chamber end of the barrel and a muzzle end of the barrel, wherein the reinforcing layer comprises a woven metal mesh pre-impregnated with a resin; and at least one carbon fiber layer positioned around the reinforcing layer(s), wherein the carbon fiber layer comprises a unidirectional carbon fiber composite material. In some embodiments, the invention provides a method of manufacturing a reinforced shaft for a rifle barrel, comprising: wrapping at least one reinforcing layer around the outer surface of a steel rifle barrel between a chamber end of the barrel and a muzzle end of the barrel, wherein the reinforcing layer comprises a woven metal mesh pre-impregnated with a resin; and wrapping at least one carbon fiber layer around the reinforcing layer(s), wherein the carbon fiber layer comprises a unidirectional carbon fiber composite material. In some embodiments, the mesh comprises stainless steel. In some embodiments, the mesh comprises neodymium. In some embodiments, the mesh has a standard or Dutch weave. In some embodiments, the resin is an epoxy resin. In some embodiments, the mesh has at least 150×150 wires per square inch. In some embodiments, the mesh comprises wire having a diameter less than or equal to about 0.001 inches (0.0254 mm).
In some embodiments, the reinforcing layer 150 may comprise a minimum of two consecutive wraps of metal mesh pre-preg. For example, in some embodiments, the metal mesh weave may be prone to open up during the curing. This opening can create a structural problem in that when the material opens up during the curing of the epoxy resin it creates an opening in the weave, which can displace the surrounding material and potentially cause a structural failure. By placing a continuous double wrap of the metal mesh weave in the structure, the chance of the metal mesh opening up during curing may be reduced or eliminated. See, for example,
In some embodiments, when a reinforcing layer 150 comprising a metal mesh weave as described above is incorporated into a structure such as an arrow or a golf shaft, the dynamic response is very different than the same structures that do not have any of the metal mesh weave in them. For example, in two otherwise identical arrows, the arrow that contains the metal mesh weave will respond much faster downrange immediately after being fired out of a bow. It was previously considered that two arrows that have the same OD, ID, static stiffness and weight should respond identically from being shot from a bow. The present inventors discovered that if one of these two arrows contains a reinforcing layer 150 comprising a metal mesh weave (e.g., stainless steel weave) as described above, that the arrow recovers much faster during the launch phase of an arrow and thus is more accurate and has a higher kinetic energy by reducing the amount of energy lost during the arrow response phase after being fired.
In the case of golf shafts, one of the key attributes, and one of the major hurdles especially for shafts designed for iron head applications, has been a wide range of variability in shot consistency. This is one of the main reasons why virtually all Tour players for the most part still use steel shafts in their irons. Many factors can contribute to this variability including: flaws in manufacturing, using an anisotropic material like carbon/epoxy compared to an isotropic material like steel, and variations along the length of a composite shaft in bending stiffness. For over 30 years, graphite golf shaft manufacturers have worked diligently to overcome these inherent issues with graphite shafts to no avail.
The present inventors identified that the effect of the metal mesh weave that was observed on an arrow might be applied to a golf shaft. In the case of an arrow, one can shoot an arrow through paper targets and place these targets at different distances from where the arrow leaves the bow. It can be determined based on the ghost imprint left on the paper as the arrow travels through the paper target, the orientation and direction of the arrow as it travels downrange. This is difficult to quantify due to the speeds involved; however the present inventors have determined that arrows with a reinforcing layer 150 comprising a metal mesh weave as described above recover much faster dynamically than an arrow without the weave.
In golf shafts with stainless steel weave according to embodiments of the present invention, the weave may be used locally increase the density of the shaft in certain areas while at the same time using the mechanical properties of stainless steel to provide added stiffness and reducing torque levels compared to simply using a densified resin with tungsten powder that only provides increased density but adds nothing to the strength or stiffness to the shaft.
One of the first things noted when the stainless steel weave was incorporated into a golf shaft design was that the shafts had a different but pleasing feel to them and also the sound at impact changed, indicating that the stainless steel weave was providing some damping improvement. In some embodiments, golf shafts according to the present invention may incorporate a lighter weight stainless steel weave, such as the feather-weight metal mesh material described above. With this lighter weight mesh, a full-length ply of the stainless steel weave may be placed into a design. In some embodiments, the thicker stainless steel weave was over three times thicker and heavier than the lighter weight mesh. One of the challenges faced, however, was that unlike an arrow shaft, which can be shot through a paper target to determine the rate of recovery as described above, there was no way to accurately determine the rate of recovery of a golf shaft other than having players hit clubs with various shafts and measure ball flight characteristics using a Trackman. This technique is very useful and generates a myriad of data; however, the data for the most part is after the ball has been impacted by the club face, and thus reveals very little about the shaft dynamics. Ideally, a shaft should come back to its “neutral” or unloaded state just prior to impacting the golf ball which allows the head to square up to the ball which minimizes the loss of energy (longer distance) and also increases the downrange accuracy of the ball.
Accordingly, to determine the recovery rate for golf shafts of the present invention, inventors employed a non-contact measurement technology that has the ability to capture the motion of an object in space and at relatively high speeds. This technology is not just a simple high speed camera system, it is a network of six high speed cameras with an algorithm that can capture and quantify the movement of an object in space. This is extremely important because it is one thing to be able to see, as in the case of an arrow, if one design recovers faster than another design by stating it qualitatively. It is another thing to be able to quantify the actual recovery rate.
This non-contact technique is especially critical in golf, where a human being is swinging a golf club at a high speed through space dynamically. The only dynamic testing typically performed for golf shafts is bending stiffness measured on a frequency machine and measured in cycles per minute. However, this test is performed by having the grip end firmly held in one position while a load is being applied, whereas in the actual swinging of a golf club, nothing is held in such a position. The club itself is moving through space attached to a golfer's hands and a head is attached to the other end, which is three-dimensional in shape and has variations in how the head mass is distributed. Therefore, up until now there has been no capability to perform dynamic testing with a golf club and obtain actual data on how the golf shaft is responding during a swing. Now, the present inventors have confirmed that the static tests that have been relied upon for the last 40 years can be augmented by using this non-contact testing capability; coupling these two testing technologies together, it is possible to identify differences between static shaft properties and dynamic shaft properties.
Referring to
Turning to
In some embodiments, as shown in
In some embodiments, methods of manufacture according to the present invention include methods to measure/test the response rate and moment of impact of the club during the swing and at the moment of impact with the golf ball.
The reinforced shaft embodiment of
In some embodiments, the invention provides hollow golf club shaft comprising a plurality of layers which contain one or more non-isotropic layer(s) of a metallic woven reinforcement oriented within the length of the golf club shaft.
In some embodiments, the layer(s) of the metallic woven reinforcement comprise one or more of the following metals: stainless steel, nickel, titanium, copper, aluminum, magnesium, and hybrid alloys made of such metals.
In some embodiments, the non-isotropic metallic woven fabric can be placed in different locations within the hollow shaft structure to achieve desired performance properties such as balance point, stiffness, torque, etc.
In some embodiments, the metallic woven material extends in a continuous fashion over the full length of the golf shaft.
In some embodiments, the fiber orientation of the non-isotropic metallic weave is at a zero- and ninety-degree fiber orientation, where the zero-degree metallic filaments are in line with the axial (longitudinal) direction of the golf shaft and the ninety-degree orientation is perpendicular to the axial direction (hoop).
In some embodiments, the thickness of said metallic weave is within a range of 0.001″ to 0.008″ in ply thickness.
In some embodiments, the non-isotropic metallic weave is impregnated with an epoxy or thermoplastic resin which is then placed within the surrounding layers of the other non-isotropic composite materials comprising at least one of the following reinforcement materials: carbon fiber, graphite fibers, fiberglass fibers, other metallic fibers, PBO fibers, aramid fibers, aromatic polyester fibers, and carbon nanotubes.
In some embodiments, placing full length ply(s) of said metallic weave increases the recovery rate of the golf shaft during the downswing of the golf club providing a longer more consistent range of club face orientation in reference to the golf ball before impact.
In some embodiments, the addition of a non-isotropic metallic weave reduces the ball strike impact area on the face of the club resulting in an increase in accuracy and distance due to the energy and accuracy lost by having a wide range of impact locations on the club face associated with steel and composite golf shafts.
In some embodiments, placing sub full length ply(s) of said metallic weave in different areas of the golf shaft, reduces tube deformation and increases the density in such areas where the metallic weave is placed.
In some embodiments, utilizing a metallic weave versus a metallic filament or an isotropic densified filler material like tungsten powder, the metallic weave provides for a significant increase in strength due to the nature of the woven continuous fiber filaments contained in the weave. This provides not only an increase in density where the weave is located, but also adds significant strength and enables the shaft to recover faster during the swing.
While there have been shown and described fundamental novel features of the invention as applied to the preferred and illustrative embodiments thereof, it will be understood that omissions and substitutions and changes in the form and details of the disclosed invention may be made by those skilled in the art without departing from the spirit of the invention. Moreover, as is readily apparent, numerous modifications and changes may readily occur to those skilled in the art. For example, various features and structures of the different embodiments discussed herein may be combined and interchanged. Hence, it is not desired to limit the invention to the exact construction and operation shown and described and, accordingly, all suitable modification equivalents may be resorted to falling within the scope of the invention as claimed. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.
This application claims the benefit of U.S. Provisional Application No. 63/086,017 filed Sep. 30, 2020, which is incorporated by reference herein in its entirety. This application is a continuation-in-part of U.S. application Ser. No. 15/639,654 filed Jun. 30, 2017 and issued Feb. 2, 2021 as U.S. Pat. No. 10,907,942, which claims the benefit of U.S. Provisional Application No. 62/357,778 filed Jul. 1, 2016 and U.S. Provisional Application No. 62/374,508 filed Aug. 12, 2016, each of which is incorporated by reference herein in its entirety.
Number | Date | Country | |
---|---|---|---|
63086017 | Sep 2020 | US | |
62374508 | Aug 2016 | US | |
62357778 | Jul 2016 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 15639654 | Jun 2017 | US |
Child | 17165721 | US |