Abstract: A golf club shaft having a hollow body comprised of a fiber and resin composite and a tube-shaped stiffener substantially surrounding a lower portion of the body which comprises a material other than a fiber and resin composite. The stiffener is preferably a metal and comprises a pre-formed sheath.

Abstract: A shaft for a golf club includes a main shaft, a ring shaft and a flex shaft which are mounted onto the distal end of the main shaft, and a sleeve which may be used to cover the ring shaft portion and the flex shaft portion. Each portion of the shaft is made of a material that is specifically selected for its particular modulus of elasticity, and the modulus of each portion is selected relative to the moduli of the other portions. For the present invention, the ring shaft portion has the highest modulus of elasticity, and the flex shaft portion has the lowest. With this combination, a club head is affixed to the extreme distal end of the main shaft, and a grip is attached to the proximal end of the main shaft portion.

Abstract: Disclosed is a golf club group comprising a plurality of golf clubs having the same number, in which each golf club shaft of the golf club is composed of a plurality of bias layers and a plurality of straight layers which are wind-formed so that it may be shaped into a tapered circular pipe having a diameter which gradually larger towards to is a butt end. The plurality of golf club shafts have approximately the same flexibility, assuming that each golf club shaft is constructed so that each straight layer may have the same thickness over the total length of the shaft, a distribution curve of flexural rigidity the shaft is set as a reference curve.

Abstract: The present invention relates to a golf club shaft which is easy to be gripped, and superior in strength and balance in its shaft portion. A golf club shaft is constituted by fiber-reinforced prepreg formed from reinforcing fibers impregnated with synthetic resin. A small-diameter portion is provided on a head side, a large-diameter portion is provided on a grip side, and a tapered portion is provided between the small-diameter portion and the large-diameter portion. An outer diameter of the small-diameter portion at its rear end portion is made smaller by 2 mm or more than an outer diameter of the large-diameter portion at its front end portion, and bending rigidity at the rear end portion is made to be 60 to 100% of that at the front end portion.

Abstract: A golf club shaft wherein an outer diameter of a base end of a grip side is arranged to be 16.5 mm to 26.0 mm, and weight of the shaft is arranged to be 30 g to 55 g. Low bend point rate determined by a formula {backward flex/(forward flex+backward flex)}.times.100 is set to be 55% to 61%.

Abstract: A lightweight shaft 22 includes a plurality of non-metallic fibers 42, 63, 66 and 70 arranged in prescribed orientations from one end of the shaft to the other and carried by a cured plastic material 103. Additional fibers 82 and 84 are carried by the cured plastic material 103 and are located at a butt end 28 of the shaft 22 to form a strengthening band 104 which precludes splitting and cracking of the shaft at the butt end. A lightweight filler element 106, which is composed of a rigid foam material, is located within a portion 27a of an opening 27 at a tip end 30 of the shaft 22 to strengthen the tip end.

Abstract: Tubular golf club shaft made from composite materials comprising layers of fibers impregnated with plastic resin and provided over its length with at least one are of enlargement (6) and or narrowing. The curve of generation of the internal diameter of the shaft as a function of its length beginning at the point of the smallest internal diameter and extending to at least one of the ends of the shaft incorporates at least one decreasing portion.

Abstract: A golf club shaft which can enhance the directivity of a golf ball. In the golf club shaft, the kick point and the position at which the torsional rigidity in the circumferential direction is lowest are set at a position distant from the front end portion of the shaft by 30 to 50% with respect to the overall length of the shaft and made to coincide substantially with each other.

Abstract: A golf club shaft having a stiffness control section between the grip section and the main body section. The stiffness control section includes a first tapered portion and a second tapered portion. The circumference of the first tapered portion increases from the proximal end to the distal end thereof and the circumference of the second tapered portion decreases from the proximal end to the distal end thereof.

Abstract: In the field of golf equipment, a new shaft design incorporates passive damping to suppress the vibrations excited in the shaft before and after impact. The design comprises a viscoelastic material sandwiched between multiple layers of composite plies which induce large shear strains in the viscoelastic when the shaft is subjected to bending, extension, or twist, thus increasing damping losses over conventional golf shafts. In one embodiment, the sandwiching layers are of opposing orientation. In another embodiment, the layers are oriented in an opposing V-shape laminate.

Abstract: A method for manufacturing a plurality of club shafts for an individually matched set of golf clubs is provided herein. The method includes using a specifically designed and separate mandrel for each club shaft of the matched set. Further, the method includes sequentially wrapping a specifically designed and separate group of patterns around each mandrel for each club shaft of the matched set. This procedure allows the manufacturer to specifically design each club shaft of the set of golf clubs. The resulting individually matched set of golf clubs has more consistent feel, flexure, frequency, weighting and torque characteristics. Additionally, the club shafts provided herein have improved swing weight characteristics for lighter heads.

Abstract: A light-weight handle is disclosed for use on new or existing golf clubs regardless of their shaft material. The handle comprises an elongated tubular member having a radially expanded gripping surface and a way for attaching the handle to a golf club shaft.

Abstract: A golf club is formed of a plurality of unit members of a plastic composite material reinforced by fiber braids. The unit members are tubular in shape and are connected end to end such that their axes are aligned and that the inner diameter and the outer diameter of the golf club are progressively increased in a steplike manner from the small end of the golf club towards the large end of the golf club.

Abstract: A golf club shaft that is light in weight but which avoids problems related to a bending deformation of the section where these phenomena might otherwise occur. The bending strength of the shaft in the area sensitive to these phenomena is improved and the flexional and torsional stiffness characteristics are not significantly affected. Further, the mass and the mass distribution of the shaft are not significantly affected. According to one embodiment, the golf club shaft is tubular and includes a variable cross section along its length. The shaft has an enlarged butt at one end an a smaller radius tip at the opposite end. The shaft includes several layers of reinforcing fibers having different orientations with respect to the longitudinal axis, at least one of the layers being oriented at, or approximately at, 90.degree. with respect to the longitudinal axis at least over a portion of the shaft where the external radius/thickness ratio is greater than or equal to 4.

Abstract: A lightweight shaft 22 of generally tubular configuration, for with a golf club 20, is formed with a first layer 34 of a non-metallic composite material of a given density including graphite fibers 86 and cured epoxy resin 86. A second layer 38 of the shaft 22 is composed of a two foam half-forms 124, or a foam full-form 142, having a density which is lower than the given density and which are located around at least a portion of the length of the first layer 34. A third layer 40 of the shaft 22 is also composed of a non-metallic composite material including graphite fibers 86 and cured epoxy resin 86 which is located around the second layer 38 of the shaft 22. A portion of the third layer 38 is also located about the first layer 34 at a tip end 30 of the shaft 22.

Abstract: An improved composite golf club shaft and method for its manufacture, and an improved club incorporating the shaft. The shaft includes a first elongate segment for mounting the golf club head and a second elongate frustoconical segment for gripping. The first segment is formed by wrapping sheet material around a substantially cylindrical mandrel, and the second elongate frustoconical segment is formed therearound to produce a smoothly tapering exterior surface of the shaft having an abrupt interior region of joinder between the segments. Such joinder preferably is approximately one-third of the way between the gripping end and the head-mounting end of the shaft. The shaft tapers such that its head-mounting end is less than approximately one-third the diameter of the gripping end. Greatly improved torque and drive distance are achievable with a club made with the shaft. The shaft is also lighter and capable of being used without the addition of a grip.

Abstract: In a preferred embodiment, a shaft for a golf club, the shaft including: tip and butt ends defined at opposite distal ends of the shaft's length; and the shaft having a balance point axially spaced from the tip end a distance in the range of from about 56 percent to about 58.5 percent of the shaft's length.

Abstract: A lightweight shaft 22 of generally tubular configuration, for use with a golf club 20, is formed with a first layer 34 of a non-metallic composite material of a given density including graphite fibers 86 and cured epoxy resin 86. A second layer 38 of the shaft 22 is composed of a two foam half-forms 124, or a foam full-form 142, having a density which is lower than the given density and which are located around at least a portion of the length of the first layer 34. A third layer 40 of the shaft 22 is also composed of a non-metallic composite material including graphite fibers 86 and cured epoxy resin 86 which is located around the second layer 38 of the shaft 22. A portion of the third layer 38 is also located about the first layer 34 at a tip end 30 of the shaft 22.

Abstract: Disclosed is a golf club comprising a shaft having a longitudinal axis. On the shaft is a hosel, and a head is securable on the hosel. When the head is secured on the hosel it may be used to strike a golf ball. The head is slidably adjustable along at least a portion of the hosel to a selected distance from the longitudinal axis of the shaft. Preferably, the selected distance may be greater than the diameter of the golf ball.

Abstract: A golf club shaft including a base rod and a hosel section of a substantially uniform predetermined thickness extending radially outwardly from a portion of club head end of the base rod. The length of hosel section is substantially greater than the length of the club head hosel recess into which the shaft will be inserted.

Abstract: Tubular golf club shaft made from composite materials comprising layers of fibers impregnated with plastic resin and provided over its length with at least one area of enlargement and/or narrowing. The curve of generation of the internal diameter of the shaft as a function of its length beginning at the point of the smallest internal diameter and extending to at least one of the ends of the shaft incorporates at least one decreasing portion.

Abstract: A racket frame, which has a frame main body 12 made of a fiber reinforced plastic, an ionomer film 13 covering the frame main body 12, and a coating film 15 formed over the ionomer film 13, is provided with a gas permeable porous material film 14 interposed between the ionomer film 13 and the coating film 15 so as to reduce voids inside the frame main body 12 and between the frame main body 12 and the ionomer film 13. Since voids are reduced inside the frame main body 12 and between the frame main body 12 and the ionomer film 13, and since the ionomer film 13 is reinforced with the gas permeable porous material film 14, the racket frame has an excellent mechanical strength. Adhesion between the frame main body 12 and the ionomer film 13 is excellent. Adhesion between the gas permeable porous material film 14 and the coating film 15 is good.

Abstract: A golf club shaft is formed of a fiber-reinforced plastic is disclosed which has a constant inside diameter of at least 7 mm between the tip end and a point G1 and a varying inside diameter increasing from the point G1 to a point G2, wherein G1 and G2 are located at positions spaced apart from the tip end distances equal to 20-50% and 70-100% of the length of the shaft, respectively. The shaft has a constant outer diameter of at least 8 mm between the tip end and a point H1 which is spaced apart from the tip end a distance equal to 20-170 mm, a varying outer diameter decreasing from H1 a point F1 which is spaced apart from the tip end a distance equal to 10-45% of the shaft, a constant diameter from F1 to a point F2 which is spaced apart from F1 a distance equal to 0-300 mm and a varying outer diameter increasing from F2 to a point H2 which is spaced apart from the grip end a distance equal to 0-300 mm.

Abstract: A golf club shaft is composed of a fiber layer formed by employing a filament winding process using filaments each impregnated with a thermosetting resin, and a reinforcement layer formed by partially inserting a braid impregnated with a thermosetting resin onto a predetermined position on the fiber layer. A method of producing a golf club shaft of the foregoing type comprises a step of winding filaments each impregnated with a thermosetting resin around a mandrel to form a fiber layer, a step of inserting a braid composed of filaments each impregnated with a thermosetting resin onto a predetermined position on the fiber layer, a step of allowing the thermosetting resin to be thermally cured, and a step of disconnecting the mandrel.

Abstract: A golf club shaft according to the present invention is formed by winding annularly and unitarily in an overlapping state a reinforcing layer of a resin film comprising an organic polymer around the outer surface of a club shaft body of a fiber-reinforced resin in a manner that the reinforcing layer extends in a limited range from a front end of the club shaft body to the portion thereof which is not less than 150 mm and not more than 500 mm distant therefrom.

Abstract: An improved golf club includes a shaft having a noncircular cross section along at least a portion thereof and a club head. The shaft provides increased rigidity in a direction transverse to intended ball impact and a desirable flex characteristic in the direction of intended ball impact. The non-circular cross section of the shaft has a first a dimension in the direction of ball impact and a second dimension transverse to the direction of ball impact. Greater flexibility of the shaft in the direction of ball impact than in the direction transverse to the direction of ball impact is assured by making the first dimension of the shaft cross section smaller than the second dimension. To provide greater flexibility of the shaft in the vicinity of the club head, the shaft may be tapered.

Abstract: A golf club shaft having a high modulus of elasticity in the grip end of the shaft to enhance stiffness, and a low modulus of elasticity in the tip end of the shaft to provide flexibility, and a method of manufacturing such a golf club shaft is disclosed.

Abstract: A light weight golf club shaft is described having a "modified hourglass" shape which provides many predetermined combinations of flex, stiffness and torque (which together are perceived as shaft and club "feel") and which is largely immune to breakage in normal play. The shaft is an improvement over our previous shaft defined in U.S. Pat. No. 5,265,872, and reduces shaft weight to the level desired by a golfer by using a substantially uniform shaft wall thickness while maintaining the unique "hour glass" external profile of our previous shaft. The shaft is formed of a base with axial sections: a grip section, an upper flare section, a flex control section, a lower flare section, and a hosel section, the whole forming an exterior shaft profile. The shaft may be made from metal such as steel, titanium, aluminum or their alloys, or composites formed of reinforcing fibers and polymeric materials.

Abstract: The invention relates to a shaft for a golf club, or to a club equipped with such a shaft. On at least 30% of the length of the shaft, its peripheral wall includes at least two layers, i.e., a first layer made of a material of density (.rho.1) and of longitudinal Young's modulus (E1), and a second layer made of a material of density (.rho.2) and of longitudinal Young's modulus (E2), the first and second layers being separated by a separation layer made of a substantially isotropic material having a density (.rho.3) and a longitudinal Young's modulus (E3), the densities (.rho.1, .rho.2) of the materials of the first and second layers being greater than the density (.rho.3) of the material of the separation layer, the longitudinal Young's moduli (E1, E2) of the materials of the first and second layers being respectively greater than 20 GPa, and the longitudinal Young's modulus (E3) of the material of the separation layer being lower than 20 GPa.

Abstract: The invention relates to a golf club by which a soft ball hitting feeling can be obtained while the excellent orientation of a ball peculiar to a hollow metallic head is maintained. A shaft is inserted into a hosel attaching section of a hollow metallic head through a hosel. The head is made of magnesium alloy or aluminum alloy, and the shaft is made of carbon fiber reinforced resin. The hosel is made of synthetic resin, the rigidity of which is lower than that of the shaft.

Abstract: A golf club shaft is made of a composite material and includes an upper portion with an enlarged lower end section, and a lower portion with an enlarged upper end section which is adjacent to the enlarged lower end section of the upper portion. The enlarged lower and upper end sections define a contracted section therebetween near the middle portion of the shaft. The upper portion decreases in diameter from the upper end thereof to the upper end of the enlarged lower end section and has a maximum diameter at an axial point which is located on the enlarged lower end section. The upper end of the upper portion is adapted to couple with a grip. The lower portion increases in diameter from the lower end thereof to the lower end of the enlarged upper end section and has a maximum diameter at another axial point which is located on the enlarged upper end section. The lower end of the lower portion is adapted to couple with a club head.

Abstract: A composite prepreg for producing a tennis racket, which is light and tough and superior in flexibility and vibration absorption abilities, comprises thermosetting resin and reinforcing fibers, wherein the reinforcing fibers are a combination of (a) aromatic polyamide or polyester fibers and (b) carbon fibers, the fibers (a) being formed into a first type of strand and the fibers (b) being formed into a second type of strand, the first and second types of strand being arranged with certain regularity. The present invention is also directed to a tennis racket comprising a circular frame constituting a ball hitting area and a shaft connecting with the circular frame, the frame and shaft having a plurality of layers structured so that at least one layer is formed from the above described composite prepreg.

Abstract: A golf putter for use with a putter shaft supporting a head, the head comprising a putter body having a heel, toe, and sole defining a bottom wall, and a front wall, the body elongated between the heel and toe, and; the body having at least one recess projecting forwardly toward a plane defined by the front wall; and the body having a second recess sunk in the front wall, there being a non-metallic face plate having a periphery received in the second recess and bonded to the body.

Abstract: A structure and method for producing golf club heads from fiber reinforced plastic is described. A long fiber reinforced thermoplastic material is used to injection mold the golf club head. The long fiber reinforced thermoplastic material provides three-dimensional strength and stiffness. The long fiber reinforced thermoplastic material is injected into a mold so that the fibers become entangled with each other. Entangled fibers provide increased strength and stiffness in more than a single direction. A sole plate and face plate are also provided. Because of the strength and rigidity of the material used to fabricate the golf club head, the face plate may be fabricated from materials not otherwise useable. A flexible thermoplastic foam block is positioned in the interior of the golf club head to prevent rattle and to provide a realistic wood sound when hitting a golf ball.

Abstract: The invention is related to a golf club shaft with improved distribution of flexibility. It includes a tubular section whose flexional rigidity evolves according to the length and has several portions, including a rigid upper portion extending from the upper end of the shaft having the largest diameter, having a length (L1) at least equal to 200 mm and whose flexional rigidity is at least equal to 50 N.multidot.m.sup.2 ; a central portion joined to the other end of upper portion having a length (L2); a lower portion joined to central portion, having a length (L3) and extending to the lower end adapted to receive the club head; the central portion being constituted of a flexible zone of a length between 100 and 300 mm of a remaining zone having a flexional rigidity greater or equal to 50 N.multidot.m.sup.2.

Abstract: A light weight golf club shaft is disclosed which has an average weight of not greater than 1.4 g per inch and which is composed of an inner tubular layer of a carbon fiber reinforced plastic having a fiber orientation angle of 40 to 50 degrees with respect to the longitudinal axis of the shaft and an outer tubular layer of a carbon fiber reinforced plastic provided around the inner layer and having a fiber orientation angle of 5 to 30 degrees. The inner layer is obtained from a prepreg sheet by a sheet winding method, while the outer layer is obtained from a roving carbon fibers by a filament winding method. The inner layer has been hardened before the winding of the roving. A reinforcing layer obtained from a prepreg and having a fiber orientation angle of 0 to 5 degrees is provided inside of the inner layer at the tip portion of the shaft.

Abstract: A shaft for a golf club includes a tubular main body made of a fiber-reinforced resin and being 10 mm or less in the outside diameter of the tip of the body. The outside circumferential surface of the main body is tapered from the butt thereof to the tip thereof at a ratio of 0/1,000 to 4/1,000 so as to be nearly uniform in diameter. The thickness of the main body is gradually increased from the tip thereof to the butt thereof. The golf club having the shaft, receives a low resistance of air, and has a rigidity appropriate for a powerful golfer who swings the club quickly.

Abstract: The proportion of the torsional rigidity of a base end side grip portion to that of an end side portion fitted with a club head ranges between (1:1) and (4:1). As a result, a golf club shaft arranged so as to have such a proportion of torsional rigidity is increased in the torsional angle of the base end side grip portion thereof as compared with the end side portion thereof which is fitted with the club head thereof.

Abstract: The outer circumferential surface of a mandrel in a bar-shaped configuration is wound with reinforced fiber impregnated with a resin. This reinforced fiber is heat-treated and hardened, to thereby form a reinforced fiber layer in a tubular configuration around the mandrel. The mandrel is provided with a reduced portion in the axial middle thereof, which is decreased in the outside diameter thereof. This mandrel comprises a basic end side member and a terminal end side member which are both connected such that they can be separated at the reduced portion. The separation of both component members of the mandrel is conducted axially in opposite directions, and this allows the detachment of the mandrel out of the reinforced fiber layer.

Abstract: A golf club head includes: a hosel portion for connection with a shaft; and a base metal body formed integrally with the hosel portion by a metal material so as to continue to the hosel portion, the base metal body being constituted by a sole portion, a top portion and a space portion formed between the sole portion and the top portion and filled with a filling member, the sole portion and the top portion being formed so as to be substantially equal in weight to each other, the space portion being placed in a sweet-spot corresponding position so that the space portion corresponds to a sweet spot, the filling member being formed by a material smaller in specific gravity than the base metal body.

Abstract: A golf club head which is more durable, capable of driving a golf ball further and providing a desirable, "soft" feeling when hitting the golf ball. These objectives are achieved by configuring the head to efficiently transmit and store potential energy due to impact with the golf ball. The head comprises a hollow shell defining a cup portion and an opening or concave portion which receives a face plate. The face plate forms a contact surface for striking a golf ball. The structural arrangement causes the hollow shell to elastically deform upon contact with a golf ball to enhance driving performance.

Abstract: A golf club putter head made of a wear resistant and highly polished, aesthetically pleasing silicon nitride material in a manufacturing process which obviates labor intensive machining and finishing. Except for the optional addition of high density material weights at the toe and heel portions of the putter head, the present invention provides a putter head which is made of a monolithic silicon nitride ceramic which has a relatively low density of 3.3 grams per cubic centimeter and which is provided with a polished surface appearance along most of its surfaces. The present invention is preferably fabricated using a process of which the most important step is a high pressure, dry pressing step in which the unique shape of the golf club head described herein facilitates bi-axial symmetric pressure application resulting in what is known as a green part.

Abstract: An ironhead comprising a relatively heavy, inner core member, preferably of metal, and a relatively lightweight, injection-molded outer member, preferably of thermoplastic elastomer, is disclosed. Preferred thermoplastic elastomer materials are glass filled urethanes and glass-filled polycarbonates. Alternative inner core designs are disclosed, both with and without a lateral support member for the striking face of the clubhead.

Abstract: A method of manufacturing filament-wound tubes or shafts includes drywinding a plurality of elongate mandrels with the filament, inserting the filament wound mandrels into respective elongate hollow molds of a mold complex, and injecting resin such as epoxy resin under pressure into the hollow molds into intimate contact with the filament. Heat is then supplied to the mold complex to heat the resin to a predetermined temperature and for a predetermined period of time to cure the resin and thereby form the tubes or shafts. The mandrels and tubes or shafts are removed from the hollow molds and then the mandrels are removed from the tubes or shafts. Many of these activities are carried out in parallel to increase the manufacturing throughput of the tubes or shafts.

Abstract: A composite golf head includes a head portion which is made of a carbon fiber composite material. The head portion has a front face, a rear face opposed to the front face, a top face, and a bottom face opposed to the top face. A metal reinforcing plate is fixed to the front face. The metal reinforcing plate has an upper extension fixed to a first part of the top portion. The metal reinforcing plate has a lower extension fixed to and wrapping around the bottom face and the rear face and extending to a second part of the top face.

Abstract: An iron or wood golf club head 60 designed to strike a golf ball so that it flies straight in a desired direction. The golf club head 60 consists generally of a striking surface 61, including a leading edge 62, and a hosel member 65, which provides a socket for insertion of a shaft member 69. The hosel member 65, connected to the striking surface 61, extends from the club head 60 substantially perpendicular to the leading edge and bends at an obtuse angle relative to the hosel portion which is connected to the striking surface 61. A straight type shaft 69 is inserted into a socket of the hosel member 65.

Abstract: An iron golf clubhead includes a blade which is formed from a first material and a hosel and a junction portion which are formed from a second material which is less dense than the material of the blade. The blade includes a toe end and a heel end and a flat bracket which extends from the heel end. The junction portion surrounds the bracket and is secured thereto.

Abstract: A golf club having a fiber-reinforced resin club shaft comprising at least a plurality of bias layers having reinforcing fibers therein disposed as to be inclined to an axial direction of the shaft and a plurality of straight layers having reinforcing fibers therein disposed in parallel with the axial direction of the shaft, the bias layers and the straight layers being wound in a tubular form, and a club head, wherein a recess formed at a tip of the club shaft is fitted to a protrusion disposed at a hosel of the club head in an over-hosel arrangement, characterized in that at least one reinforcing layer having reinforcing fibers therein arranged as cross the axial direction of the shaft is disposed only in the tip portion of the club shaft.

Abstract: A golf club shaft has a grip portion at which the shaft is to be fitted with a grip, and a tip at which the shaft is to be connected to a club head. The grip portion of the shaft and the neighborhood thereof are made of a composite material comprising a fiber-reinforced synthetic resin layer and a metal layer, while the remaining portion is made of a fiber-reinforced synthetic resin.

Abstract: A golf club head including a front strike face, a sole extending rearwardly from a bottom region of the front strike face, a rear surface opposed to the front strike face, and a vibration damper provided on the rear surface. The vibration damper includes a constraining member having a high Young's modulus connected to the rear surface of the club head through an interposed visco-elastic material.