GOLF SHOES HAVING OUTSOLES WITH SECTIONS OF DIFFERING HARDNESS

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to shoes and more particularly to golf shoes having improved outsoles. Materials having different hardness properties are used to construct different sections of the outsole. For example, thermoplastic polyurethanes may be used in the exterior region and rubber materials may be used in the interior region. The outsole has improved stability and flexibility.

2. Brief Review of the Related Art

Both professional and amateur golfers use specially designed golf shoes today. Typically, the golf shoe includes an upper portion and outsole portion along with a mid-sole that connects the upper to the outsole. The upper has a traditional shape and is made from a standard upper material such as leather. The mid-sole is relatively lightweight and provides cushioning to the shoe. The mid-sole is made from a material such as ethylene vinyl acetate copolymer (EVA). The outsole includes is molded and designed to provide stability to the golfer's feet. The bottom of the outsole includes traction elements to support the golfer's feet and provide traction between the shoe and grass.

The golf shoe needs to provide sufficient stability and support for the golfer. Thus, many golf shoes include a relatively rigid material such as thermoplastic polyurethane. The plastic material helps provide stiffness and rigidity to the shoe. At the same time, the golf shoe needs to have sufficient flexibility. The foot needs to bend during walking and when swinging the golf club. The shoe should be constructed so that it is not overly rigid. The golf shoe industry has looked at different ways for improving the flexibility of the shoe, while maintaining high stability and support.

For example, Robinson, Jr. et al., U.S. Pat. No. 7,895,773 discloses a golf shoe comprising an upper, a midsole, and an outsole, wherein a collapsible support element is positioned in a recess of the outsole and close to the first metatarsal bone of the foot. The collapsible support element comprises a collapsible gel pad encased in a thermoplastic urethane, or a single collapsible element having a wave configuration, or a series of collapsible wave elements. The collapsible element is stiffer in a longitudinal direction and more collapsible in a transverse direction. This helps minimize the impact of ground forces when the golfer is walking, and it allows for more efficient transfer of energy during a golf swing.

Brown et al., U.S. Pat. No. 7,673,400 discloses a golf shoe having a generally soft and flexible base with raised portions on the lower surface of the base, a pair of flexing supports that are placed on the lower surface of the base in an abutting relationship with the raised portions, and a pair of chassis that fit over the base and a two-piece arch support that acts as a shank for the arch section of the base. Stability pods integrally molded to the bottom side of the forward and rear chassis. The shoe provides for individual movement of the foot, particularly, the rotation between the rear foot and the forefoot and flexibility longitudinally and transversely along the metatarsal area of the foot.

Robinson, Jr. et al., U.S. Pat. No. 7,143,529 and Erickson et al., U.S. Pat. No. 6,708,426 discloses golf shoes having an outsole including a forward portion and a rearward portion that are connected by a ball-and-socket connection that allows the portions to move freely. The outsole may include flexible members disposed between discrete pieces of the forward portion to allow these pieces to flex freely. The outsole also may include a pair of stabilizer rods. The outsole allows for individual movement of the foot, particularly, the rotation between the rearfoot and the forefoot. This helps resist torsional instability during play, provides independent traction suspension, and increases the flexibility of the shoe.

Robinson, Jr. et al., U.S. Pat. No. 5,979,083 discloses a golf shoe having a two-layered outsole including an outer layer and inner layer made from thermoplastic compositions. The layers outer layer forms the bottom of the outsole and has a plurality of first holes at spaced locations therethrough. The inner layer includes a base adjacent one side of the outer layer and a plurality of projections that extend from the base through the first holes in the outer layer, and terminate in a pointed free end. The projections protrude from the bottom of the outsole, and provide traction when the outsole interacts with the ground. The shoe is constructed such that it provides adequate traction during a golf swing and minimizes damage to the turf of golf courses during play.

Although some of the above-described shoes have been somewhat effective in providing sufficient rigidity as well as flexibility, there is a need for an improved outsole. The outsole should provide sufficient rigidity without sacrificing flexibility. A person wearing the shoe should be able to walk comfortably and have sufficient support. The shoe should also hold and support the medial and lateral sides of the golfer's foot as they shift their weight when making a shot. The present invention provides new golf shoe constructions that provide improved traction and support to the golfer as well as other advantageous properties, features, and benefits.

SUMMARY OF THE INVENTION

The present invention provides a golf shoe comprising upper, mid-sole, and outsole components. The upper may be made of a natural or synthetic leather material; and the mid-sole may be made of an ethylene vinyl acetate material. The outsole includes forward, mid-foot, and rearward portions. Each portion of the outsole includes: i) a central (interior) region having first traction projections that protrude from the bottom surface of the outsole, the central region and projections being made of a first material, and ii) a perimeter (exterior) region having second traction projections that protrude from the bottom surface of the outsole, the central region and projections being made of a second material. Preferably, the hardness of the second material is greater than the hardness of the first material. More particularly, the Shore A hardness of the second material is preferably greater than the Shore A hardness of the first material. In one preferred embodiment, the first material is a rubber material having a material hardness in the range of about 50 to about 70 Shore A; and the second material is thermoplastic polyurethane having a material hardness greater than about 70 Shore A and preferably about 72 to about 95 Shore A. More preferably, the hardness of the second material is at least 20% greater than the hardness of the first material.

The outsole may further include one or more flexing channels that extend transversely or longitudinally through the outsole. In addition to the traction projections, the shoe may include spikes and/or cleats. In one embodiment, the projections located in the central region of the outsole are longer than the projections located in the perimeter region. Alternatively, in another embodiment, the projections arranged in the central region of the outsole are shorter than the projections arranged in the perimeter region.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features that are characteristic of the present invention are set forth in the appended claims. However, the preferred embodiments of the invention, together with further objects and attendant advantages, are best understood by reference to the following detailed description in connection with the accompanying drawings in which:

FIG. 1 is a bottom perspective view of a golf shoe of the present invention;

FIG. 2 is a side perspective view of a golf shoe of the present invention;

FIG. 3A is a close-up view of the forward portion of the outsole of the golf shoe shown in FIGS. 1 and 2;

FIG. 3B is a close-up view of the mid-foot portion of the outsole of the golf shoe shown in FIGS. 1 and 2;

FIG. 3C is a close-up view of the rearward portion of the outsole of the golf shoe shown in FIGS. 1 and 2;

FIG. 4A-1 is a lateral view of a golf shoe of this invention (right foot) showing the rearward portion of the outsole striking the ground surface during a first stage of a person's walking cycle;

FIG. 4A-2 is a front elevation view of the golf shoe shown in FIG. 4A-1;

FIG. 4B-1 is a lateral view of a golf shoe of this invention (right foot) showing the rearward and forward portion of the outsole making contact with the ground surface during a second stage of a person's walking cycle;

FIG. 4B-2 is a front elevation view of the golf shoe shown in FIG. 4B-1;

FIG. 4C-1 is a lateral view of a golf shoe of this invention (right foot) showing the forward portion of the outsole making contact with the ground surface as a person pushes off on his/her feet during a third stage of a person's walking cycle;

FIG. 4C-2 is a front elevation view of the golf shoe shown in FIG. 4C-1;

FIG. 5A is a front elevation view of a golf shoe of this invention (right foot) showing the shoe in a neutral position as a golfer starts his/her golf shot cycle;

FIG. 5B is a front elevation view of the golf shoe shown in FIG. 5A showing the shoe rolling outwardly (to the lateral side) as the golfer engages in a golf shot cycle;

FIG. 5C is a front elevation view of the golf shoe shown in FIG. 5B showing the shoe rolling inwardly to a neutral position as the golfer engages continues the golf shot cycle; and

FIG. 5D is a front elevation view of the golf shoe shown in FIG. 5C showing the shoe rolling inwardly (to the medial side) as the golfer finishes his/her golf shot cycle.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a golf shoe having an outsole made of materials of differing hardness. Referring to FIG. 1, one embodiment of the golf shoe of this invention is shown. The shoe (10) includes an upper portion (12) and outsole portion (16) along with a midsole (14) that connects the upper (12) to the outsole (16).

The upper (12) has a traditional shape and is made from a standard upper material such as leather. An opening (18) is formed by the top portion of the upper (12) for receiving a user's foot (FIG. 2). For example, the upper (12) may be formed primarily of a substantially inelastic material including, but not limited to, natural leather, synthetic leather, other non-woven materials, natural fabric, and synthetic fabric. The leather materials help provide the shoe with good wear-resistance and comfort.

The midsole (14) is relatively lightweight and provides cushioning to the shoe. The midsole (14) may be made from a material such as ethylene vinyl acetate copolymer (EVA). In one manufacturing process, the midsole (14) is molded on and about the outsole. Alternatively, the midsole (14) may be molded as a separate piece and then joined to the outsole (16) by stitching, adhesives, or other suitable means using standard techniques known in the art. For example, the midsole (14) may be heat-pressed and bonded to the top surface of the outsole. The outsole (16) is molded from at least two materials having different hardness levels as described further below.

Basically, the anatomy of the foot can be divided into three bony regions. The rear-foot region generally includes the ankle (talus) and heel (calcaneus) bones. The mid-foot region includes the cuboid, cuneiform, and navicular bones that form the longitudinal arch of the foot. The forefoot region includes the metatarsals and the toes. Referring to FIGS. 2 and 3A-3C, different sections of the outsole (16) of this invention are shown.

The outsole (16) includes a forward portion (20) for supporting the forefoot region; a mid-foot portion (22) for supporting the mid-foot region including the arch area; and rearward portion (24) for supporting the rear-foot including heel area. The outsole (16) has a top (upper) surface (not shown) and bottom (lower) surface (26). The midsole (14) is joined to the top surface of the outsole (16). The bottom surface (26) of the outsole is configured to contact the ground during golf play and other activities as discussed further below.

As shown in FIG. 2, the outsole portion (16) generally includes two regions: a) a perimeter (exterior) region (28); and b) a central (interior) region (30). The perimeter region (28) generally extends along the periphery of the outsole (16) and substantially surrounds the central region (30). In general, measuring from the outer edge (29) of the outsole (16) in a linear direction towards the center region (30) of the outsole, the perimeter region (28) has a width of about 10 to about 50 mm, preferably about 20 to about 30 mm. The width of the perimeter region may vary along the contour of the shoe. In one preferred embodiment, the perimeter region (28) is made of a relatively hard material. For example, the perimeter region (28) may be made of a thermoplastic polyurethane composition having a durometer of greater than about 70 Shore A points, preferably about 72 to about 95 Shore A points, and more preferably about 75 to about 85 Shore A points. Suitable commercially-available polyurethanes that may be used to form the exterior region (28) include Sunko T-785 VM, available from Sunko Ink Co., Ltd. (Tali City, Taiwan). Another suitable material is thermoplastic polyurethane manufactured by Taiwan Ure-Tech Co., Ltd under the tradename, Utechilan UTY-75A-85A having about 75 to about 85 Shore A hardness. Meanwhile, the central region (30) is preferably made of a relatively soft material such as rubber. For example, the interior region (30) may be made of a rubber composition having a durometer of about 50 to about 70 Shore A points, preferably about 55 to about 65 Shore A points, and more preferably about 58 to about 62 Shore A points. In a particularly preferred embodiment, the exterior region (28) is substantially harder than the interior region (30). For example, the hardness of the exterior region (28) may be at least 20% greater than the hardness of the interior region (30), preferably at least 25% greater, and more preferably at least 30% greater.

As noted above, a thermoplastic polyurethane composition may be used to form the relatively hard perimeter region of the shoe. In general, such polyurethane compositions contain urethane linkages formed by reacting an isocyanate group (—N═C═O) with a hydroxyl group (OH). The polyurethanes are produced by the reaction of a multi-functional isocyanate (NCO—R—NCO) with a long-chain polyol having terminal hydroxyl groups (OH—OH) in the presence of a catalyst and other additives. The chain length of the polyurethane prepolymer is extended by reacting it with short-chain diols (OH—R′—OH). The resulting polyurethane has elastomeric properties because of its “hard” and “soft” segments, which are covalently bonded together. Polyester, polyether, and polycaprolactone-based polyurethanes may be used. The polyurethane may be aromatic or aliphatic based on the diisocyanates used. For example, aromatic diisocyanates include toluene 2,4-diisocyanate (TDI), toluene 2,6-diisocyanate (TDI), 4,4′-methylene diphenyl diisocyanate (MDI), 2,4′-methylene diphenyl diisocyanate (MDI), polymeric methylene diphenyl diisocyanate (PMDI), p-phenylene diisocyanate (PPDI), m-phenylene diisocyanate (PDI), naphthalene 1,5-diisocyanate (NDI), naphthalene 2,4-diisocyanate (NDI), p-xylene diisocyanate (XDI). The aromatic isocyanates are able to react with the polyol and form a durable and tough polymer having a high melting point. The resulting polyurethane generally has good mechanical strength and wear-resistance. Aliphatic diisocyanates include isophorone diisocyanate (IPDI), 1,6-hexamethylene diisocyanate (HDI), 4,4′-dicyclohexylmethane diisocyanate (“H₁₂MDI”), meta-tetramethylxylyene diisocyanate (TMXDI), trans-cyclohexane diisocyanate (CHDI), 1,3-bis(isocyanatomethyl)cyclohexane; and 1,4-bis(isocyanatomethyl)cyclohexane. The resulting polyurethane formed from these compounds generally has good light and thermal stability.

Polyurea compositions also can be used. In general, polyurea compositions contain urea linkages formed by reacting an isocyanate group (—N═C═O) with an amine group (NH or NH₂). The chain length of the polyurea prepolymer is extended by reacting the prepolymer with an amine curing agent. Hybrid poly(urethane/urea) compositions containing urethane and urea linkages also may be used. Any suitable commercial polyurethane, polyurea, and hybrids, copolymers, and blends thereof may be used in accordance with this invention. The thermoplastic polyurethanes have good physical properties such as tensile strength, toughness, flex modulus, durability, wear and tear-resistance; as well as good chemical-resistance.

Other thermoplastic elastomers that can be used in accordance with this invention include polyester-polyether block copolymers such as Hytrel® resins, available from DuPont. These block copolymers are available in different grades and contain hard (crystalline) segments of polybutylene terephthalate and soft (amorphous) segments based on long-chain polyether glycols. Polyether-amide block copolymers, which are commonly known as Pebax® resins, and are available from Arkema, Inc. (Columbs, France), also may be used. Other suitable thermoplastic polymers include, but are not limited to, ethylene acid copolymer ionomers, polyamides, polyesters, polyolefins, polyamides, polyamide-ethers, polyamide-esters; fluoropolymers, polystyrenes, polyvinyl chlorides, polycarbonates, polyethers, and polyimides including homopolymers, copolymers, and modified polymers and blends thereof.

As noted above, a rubber material may be used to form the relatively soft central region of the shoe. Suitable rubber materials that may be used include, but are not limited to, polybutadiene, polyisoprene, ethylene propylene rubber (“EPR”), ethylene-propylene-diene (“EPDM”) rubber, styrene-butadiene rubber, styrenic block copolymer rubbers (such as “SI”, “SIS”, “SB”, “SBS”, “SIBS”, “SEBS”, “SEPS” and the like, where “S” is styrene, “I” is isobutylene, “E” is ethylene, “P” is propylene, and “B” is butadiene), polyalkenamers such as, for example, polyoctenamer, butyl rubber, halobutyl rubber, polystyrene elastomers, polyethylene elastomers, polyurethane elastomers, polyurea elastomers, metallocene-catalyzed elastomers and plastomers, copolymers of isobutylene and p-alkylstyrene, halogenated copolymers of isobutylene and p-alkylstyrene, copolymers of butadiene with acrylonitrile, polychloroprene, alkyl acrylate rubber, chlorinated isoprene rubber, acrylonitrile chlorinated isoprene rubber, and blends of two or more thereof.

The rubber composition may be cured using conventional curing processes. Suitable curing processes include, for example, peroxide-curing, sulfur-curing, high-energy radiation, and combinations thereof. In one embodiment, the rubber composition contains a free-radical initiator selected from organic peroxides, high energy radiation sources capable of generating free-radicals, and combinations thereof. The rubber compositions may further include a reactive cross-linking co-agent such as zinc salts of acrylates, diacrylates, methacrylates, and dimethacrylates. A wide variety of fillers and additives may be added to the rubber materials to impart specific properties to the material. For example, relatively heavy-weight and light-weight metal fillers such as, particulate; powders; flakes; and fibers of copper, steel, brass, tungsten, titanium, aluminum, magnesium, molybdenum, cobalt, nickel, iron, lead, tin, zinc, barium, bismuth, bronze, silver, gold, and platinum, and alloys and combinations thereof may be used to adjust the specific gravity of the composition. Other additives and fillers include, but are not limited to, optical brighteners, coloring agents, fluorescent agents, whitening agents, UV absorbers, light stabilizers, surfactants, processing aids, antioxidants, stabilizers, softening agents, fragrance components, plasticizers, impact modifiers, titanium dioxide, clay, mica, talc, glass flakes, milled glass, and mixtures thereof.

As discussed above, each of the forward (20), mid-foot (22), and rearward (24) sections of the outsole include an interior region (30) comprising a first material, preferably a rubber material; and an exterior region (28) comprising a second material, preferably a thermoplastic polyurethane. It also should be understood that each portion may further comprise other materials. That is, the different sections of the outsole (20, 22, and 24) may be made from a variety of materials in addition to the above-described first and second materials having different t hardness levels.

For example, the mid-foot portion (22) of the outsole may include a logo sub-assembly (25) in a designated area. A transparent layer of plastic material (27) may be applied over the logo sub-assembly (25) to protect the logo when the outsole contacts the ground while still permitting visibility of the logo. One preferred material for the transparent layer (27) is an ester-based thermoplastic polyurethane manufactured by Taiwan Ure-Tech Co., Ltd under the tradename UTY-90A, having a Shore A hardness of about 90. Thus, in this example, the interior region (30) of the mid-foot region (22) comprises a relatively soft material such as rubber, and a relatively hard material such as the thermoplastic polyurethane used in the transparent layer (27) and logo sub-assembly (25). In another example, the forward (20), mid-foot (22), and rearward (24) sections of the outsole may include an interior region (30) comprising a relatively soft first material (rubber) and relatively soft third material (ethylene vinyl acetate); and an exterior region (28) comprising a relatively hard second material (thermoplastic polyurethane).

In another embodiment, the midsole portion (14) includes two regions: a) a perimeter (exterior) region; and b) a central (interior) region. In a manner similar to the outsole construction described above, the perimeter region is made of a relatively hard material. For example, the perimeter region may be made of an ethylene vinyl acetate (EVA) composition having a durometer of greater than about 65 Shore A, preferably about 68 to about 88 Shore A and more preferably about 70 to about 75 Shore A. Meanwhile, the central region is made of a relatively soft material such as rubber or a softer EVA composition. For example, the interior region may be made of an EVA composition having a durometer of less than about 65 Shore A, preferably about 50 to about 63 Shore A, and more preferably about 55 to about 60 Shore A. In yet another version, the midsole portion includes two layers. The first midsole layer includes the exterior and interior regions of varying hardness as described above. A second midsole layer overlays the first midsole layer and may be made of a suitable material such as a blend of EVA and Kraton® SEBS rubber. For example, a blend comprising 70 to 90% by weight EVA and 10 to 30% by weight Kraton® SEBS rubber could be used. In one preferred example, the composition comprises about 85% EVA and about 15% Kraton® SEBS rubber. Other Kraton® polymer products can be used such as Kraton® SBS, SIS, and isoprene rubber materials.

Many golf courses offer golfers the choice of driving an electric-powered cart over or walking the course. Some golfers prefer to walk the entire course. Even golfers, who prefer to drive carts, will walk a considerable distance during their round of play. Depending upon the length of the course, speed of play, and other factors, a golfer may walk a few miles in a round. Thus, a golf shoe needs to be comfortable to wear and allow a golfer to walk naturally and freely. That is, the foot needs to be supported, but the foot also must be allowed to move to some degree. Referring to FIGS. 4A-1 to 4C-2, a normal walking cycle is schematically diagramed. Typically, when a person starts naturally walking, the outer part of his/her heel strikes the ground first with the foot in a slightly supinated position. FIGS. 4A-1 and 4A-2 show different views of one version of the golf shoe of this invention (right foot) with the heel portion of the outsole striking the ground surface first as the golfer starts his/her walking gait. As the person transfers his/her weight to the inside portion of the foot, the arch of the foot is flattened, and the foot is pressed downwardly. The foot also starts to rolls slightly inwardly to a pronated position. In some instances, the foot may roll inwardly to an excessive degree and this is type of gait is referred to as over-pronation. In other instances, the foot does not roll inwardly to a sufficient degree and this is referred to as under-pronation. FIGS. 4B-1 and 4B-2 show the rearward and forward portion of the outsole making contact with the ground surface. Normal foot pressure is applied downwardly and the foot starts to move to a normal pronated position and this helps with shock absorption. After the foot has reached this neutral position (FIGS. 4B-1 and 4B-2), the person pushes off on the ball of his/her foot and continues walking (FIGS. 4C-1 and 4C-2). At this point, the foot also rolls slightly outwardly again. In FIGS. 4C-1 and 4C-2, the forward portion of the outsole is shown making contact with the ground surface as the person pushes off his/her foot and begins their next step. These continuous stresses on the outer and inner portions of the foot can cause ligaments, tendons, and muscles in the foot to feel sore and even sprain or tear. The golf shoes of the present invention help address these injury risks with their improved support around the exterior of the shoe. The shoe help provide a stable platform without sacrificing flexibility. Thus, the golfer can walk comfortably and easily with support. The golfer can easily walk with his/her natural gait. The foot is allowed to move, and yet at the same time, the motion of the foot is controlled.

More particularly, the projections (35a) located in the interior region (30) of the outsole (16) are more flexible than the projections (35b-35d) located in the exterior region (28). As discussed above, the interior region (30) contains first projections (35a) made of a relatively soft and flexible material such as rubber, while the exterior region (28) contains projections made of a harder and stiffer material such as thermoplastic polyurethane. In addition, the projections (35a) located in the interior region (30) of the outsole preferably have greater lengths than the projections (35b-35d) located in the exterior region (28). In this manner, the softer inner projections (35a) are able to contact the ground first in the walking cycle, compress more easily, and help provide flexibility to the shoe. Thus, the person can walk more comfortably. Meanwhile, in this one embodiment, the exterior region (28) contains projections (35b-35d) having a shorter length. These shorter projections (35b-35d) contact the ground subsequently to the longer projections (35a) to help provide balance and traction control.

During normal golf play, a golfer makes shots with a wide variety of clubs. As the golfer swings a club when making a shot and transfers their weight, the foot absorbs tremendous forces. For example, in many cases, when a right-handed golfer is following through on a shot, their left shoe rolls from the medial side (inside) of their left foot toward the lateral side (outside) of the left foot. Meanwhile, their right shoe rolls from the lateral side of the right foot to the medial side of the right foot. Referring to FIGS. 5A-5C, the movement of a shoe (right foot) during a golf shot cycle is schematically diagrammed FIG. 5A shows a golf shoe of this invention (right foot) in a neutral position as a golfer starts their golf shot. In FIG. 5B, the shoe is shown rolling outwardly (to the lateral side) as the golfer makes their backswing. In FIG. 5C, the golf shoe is shown rolling inwardly to a neutral position as the golfer makes their downswing. In FIG. 5D, the golfer is following through on his/her swing and the shoe is rolling inwardly (to the medial side).

As illustrated in FIGS. 5A-5D, significant pressure is applied to the exterior of the foot at various stages in the golf shot cycle. In the present invention, the exterior region (28) of the outsole (16) is designed to provide support and stability to the sides of the foot. That is, the exterior region (28) provides support around the edges (29) of the outsole. This exterior region (28) helps hold and support the medial and lateral sides of the golfer's foot as he/she shifts their weight when making a shot. On the other hand, the interior region (30) of the outsole is designed to provide comfort and cushioning to the foot. The interior region (28) is made of a relatively soft material and deforms more easily. This outsole structure helps provide comfort and support across the golfer's foot. Thus, the golfer has better stability and balance in all phases of the game including walking. In addition, the golf shoe (10) is lightweight and comfortable to wear.

The outsole also may include one or more flexing channels that extend transversely or longitudinally through it. For example, referring back to FIG. 2, in one version, the forward region (20) of the outsole (16) includes a flexing channel (32) that extends transversely along the outsole. Preferably, the flexing channel (32) in the outsole (16) is positioned so that it falls below the metatarsal area of the person wearing the shoe. The flexing channel (32) is preferably positioned to provide bending regions in the outsole (16) that correspond to the natural bending of the foot during walking.

The flexing channels (32) may be formed of a thermoplastic urethane that is substantially soft for providing additional flexibility. Preferably, the material used to form the flexing channel (32) has a hardness of less than about 85 Shore A. In one version, the material has a hardness of about 70 Shore A. One suitable polyurethane material that can be used to form the flexing channels is manufactured by Taiwan Ure-Tech Co., Ltd. under the tradename U-70AP and has a Shore A of about 70. Other suitable thermoplastic urethanes include Desmopan™ from Bayer and Pebax™ from Atofina. The outsole (16) (which contains or does not contain the flexing channels) of the present invention may be formed by various molding methods.

The golf shoe of this invention preferably includes traction projections of various shapes that protrude from the bottom surface of the outsole. The traction projections are designed to engage the ground surface and provide an increased area of contact with the ground. This helps provide the golfer with better foot traction on the turf as he walks the course and plays the round.

In FIG. 2, the outsole is shown containing four sets of traction projections (35a, 35b, 35c, and 35d). The traction projections (35a-35d), which are shown in FIG. 2, are of various shapes and sizes. The traction projections may be of any suitable shape including, but not limited to, rectangular, triangular, square, spherical, star, diamond, pyramid, arrow, rod, or conical-shapes. Also, the height and area of the traction projections may be the same or different. For example, in one embodiment (FIG. 2), the projections (35a) located in the central region (30) of the outsole are more flexible and longer than the projections (35b-35d) located in the perimeter region (28). Alternatively, in another embodiment, the projections (35a) arranged in the central region (30) of the outsole are shorter than the projections (35b-35d) arranged in the perimeter region (28).

More particularly, each of the forward (20), mid-foot (22), and rearward (24) sections of the outsole include traction projections and close-up views of these different sections are shown in FIGS. 3A-3C. The traction projections (35b, 35c, and 35d) located in the perimeter region (28) may be referred to as inner projections (35b); intermediate projections (35c); and outer projections (35d), respectively. The inner projections (35b) are disposed along the inner edge of the perimeter region (28). The outer projections (35d) are disposed along the outer edge (29) of the perimeter region (28), and the intermediate projections (35c) are disposed between the inner and outer projections (35b, 35d). In one embodiment, the inner and outer projections (35b, 35d) have smaller dimensions than the intermediate projections (35c). In another embodiment, the inner and outer projections (35b, 35d) have larger dimensions than the intermediate projections (35c). In yet another embodiment, the inner, intermediate, and outer projections (35b, 35c, and 35d) each have the same dimensions. As shown in FIGS. 3A-3C, the number and pattern of traction projections located in the forward (20) section of the outsole (16) differs from the number and pattern of the traction projections located in the mid-foot (22) section, and these differ from the traction projections in the rearward (24) section. In other embodiments, the number and pattern of traction elements may be uniform across the different section (20, 22, and 24) outsole (16). The traction projections may be of any suitable shape including, but not limited to, rectangular, triangular, square, spherical, star, diamond, pyramid, arrow, rod, or conical-shapes. Also, the height and surface area of the traction projections may be the same of different.

As discussed above, in FIG. 2, the outsole (16) includes discrete sets of projections (35a, 35b, 35c, and 35d) positioned in different areas. There are no spikes or cleats shown in the outsole (16) of FIG. 2; however, any number of spikes or cleats may be included if such traction elements are needed. A wide variety of constructions, patterns, and designs of traction elements may be used in the outsoles of this invention. It should be understood that the type, amount, dimensions, spacing, and pattern of traction projections and elements shown in FIGS. 1 to 5D are for illustrative purposes only and not meant to be restrictive. The outsole may include a wide variety of traction projections and elements in accordance with the present invention.

The bottom surface (26) of the outsole (16) may further include traction elements such spikes or cleats. If such spikes or cleats are present, they are preferably releasably fastened to sockets (receptacles) in the outsole. The socket may be located in a molded pod (not shown) attached to the outsole. The molded pod helps provide further stability and balance to the shoe. The spike may be inserted and removed easily from the receptacle. Normally, the spike may be secured in the receptacle by inserting it and then slightly twisting it in a clockwise direction. The spike may be removed from the receptacle by slightly twisting it in a counter-clockwise direction. The outsole may include any suitable amount of cleats, and the cleats can be arranged in a wide variety of patterns. Preferably, the outsole includes 5, 6, 7, 8, or 9 cleats that may be arranged in various patterns. Such releasable cleats are commercially-available from manufacturers such as Softspikes, LLC, a division of Pride Manufacturing LLC. (Brentwood, Tenn.). The cleats are preferably made of a plastic material, since most golf courses require that golfers use non-metal cleats.

In one embodiment, the interior region (30) comprising the relatively soft material constitutes about 30 to about 70% of the total surface area of the outsole (15). The exterior region (28) comprising the relatively hard material constitutes about 70% to about 30% of the total surface area of the outsole (16). More particularly, in one embodiment, referring to the rearward (heel) portion (24) of the shoe, the interior region (30) constitutes about 10% or greater of the total surface area of the rearward portion (24). Preferably, the interior region (30) constitutes about 20% or greater of the surface area of the rearward portion (24). For example, the lower limit of the interior region (surface area in the rearward portion) comprising the relatively soft material may be about 10% or 20% or 30% or 35% or 40% or 45% and the upper limit may be about 55% or 60% or 70% or 80% or 90% based on total surface area of the rearward portion (24). In one preferred embodiment, the interior region (30) constitutes about 50% of the surface area of the rearward portion (24). In another embodiment, referring to the forefoot portion (20) of the shoe, the interior region (30) constitutes 15% or greater of the total surface area of the forefoot portion, preferably 30% or greater. In yet another embodiment, referring to the mid-foot portion (22) of the shoe, the interior region (30) constitutes 20% or greater of the total surface area of the mid-foot portion, preferably 60% or greater.

Measurement of Hardness

There is a difference between “material hardness” and “hardness as measured directly on the shoe.” For purposes of the present invention, material hardness is measured according to ASTM D2240 and generally involves measuring the hardness of a flat “slab” or “button” formed of the material. Surface hardness as measured directly on a shoe (or other surface) typically results in a different hardness value. The difference in “surface hardness” and “material hardness” values is due to several factors including, but not limited to, shoe construction (that is, shoe type, number of mid-sole and outsole layers, and the like); thickness of midsole and outsole layers; and the material composition of the midsole and outsole. It also should be understood that the two measurement techniques are not linearly related and, therefore, one hardness value cannot easily be correlated to the other. Shore A material hardness was measured according to the test method ASTM D2240

It is understood that the shoe materials and structures described and illustrated herein represent only some embodiments of the invention. It is appreciated by those skilled in the art that various changes and additions can be made to materials and structures without departing from the spirit and scope of this invention. It is intended that all such embodiments be covered by the appended claims.

When numerical lower limits and numerical upper limits are set forth herein, it is contemplated that any combination of these values may be used. Other than in the operating examples, or unless otherwise expressly specified, all of the numerical ranges, amounts, values and percentages such as those for amounts of materials and others in the specification may be read as if prefaced by the word “about” even though the term “about” may not expressly appear with the value, amount or range. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention.

GOLF SHOES HAVING OUTSOLES WITH SECTIONS OF DIFFERING HARDNESS

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