GOLF CLUB WITH INTERCHANGEABLE HEAD-SHAFT CONNECTION, COMPONENTS THEREFOR, AND A METHOD OF MANUFACTURING

(Corporate Docket Number PU2640-WO)

Technical Field

The present invention relates to a golf club having an improved connection for interchanging a shaft with a golf club head, components for the golf club, and a method of manufacturing the components. B ackground Art hi order to improve their game, golfers often customize their equipment to fit their particular swing. Golf equipment manufacturers have responded by increasing the variety of clubs available to golfers. For example, a particular model of a driver- type golf club may be offered in several different loft angles and lie angles to suit a particular golfer's needs, hi addition, golfers can choose shafts, whether metal or graphite, and adjust the length of the shaft to suit their swing. Golf clubs that allow shaft and club head components to be easily interchanged facilitate this customization process.

One example is Wheeler, U.S. Patent No. 3,524,646 for a Golf Club Assembly. The Wheeler patent discloses a putter having a grip and a putter head, both of which are detachable from a shaft. Fastening members, provided on the upper and lower ends of the shaft, have internal threads, which engage the external threads provided on both the lower end of the grip and the upper end of the putter head shank to secure these components to the shaft. The lower portion of the shaft further includes a flange, which contacts the upper end of the putter head shank, when the putter head is coupled to the shaft. Another example is Walker, U.S. Patent No. 5,433,442 for Golf Clubs with

Quick Release Heads. The Walker patent discloses a golf club in which the club head is secured to the shaft by a coupling rod and a quick release pin. The upper end of the coupling rod has external threads that and engage the internal threads formed in the lower portion of the shaft. The lower end of the coupling rod, which is inserted into the hosel of the club head, has diametric apertures that align with diametric apertures in the hosel to receive the quick release pin.

Still another example is Roark, U.S. Patent No. 6,547,673 for an Interchangeable Golf Club Head and Adjustable Handle System. The Roark patent discloses a golf club with a quick release for detaching a club head from a shaft. The quick release is a two-piece connector including a lower connector, which is secured in the hosel of the club head, and an upper connector, which is secured in the lower portion of the shaft. The upper connector has a pin and a ball catch that protrude radially outward from the lower end of the upper connector. The upper end of the lower connector has a slot formed therein for receiving the upper connector pin, and a separate hole for receiving the ball catch. When the shaft is coupled to the club head, the lower connector hole retains the ball catch to secure the shaft to the club head.

Two further examples are published applications to Burrows, U.S. Pub. Nos. 2004/0018886 and 2004/0018887, both of which are for a Temporary Golf Club Shaft-Component Connection. The Burrows applications disclose a temporary connection that includes an adapter insert, a socket member, and a mechanical fastener. The adapter insert, which is mounted on a shaft, includes a thrust flange. The socket member, which is mounted on the other golf club component (e.g., a club head), includes a thrust seat for seated reception of the thrust flange. The mechanical fastener (e.g., a compression nut or a lock bolt) removably interconnects the adapter insert and the socket member.

The prior art temporary head-shaft connections have several disadvantages. First, they require that the golf club head have a conventional hosel for attachment. Second, these connections add excessive weight to the club head, thereby minimizing the amount of discretionary mass that may be distributed in the club head to optimize mass properties. Third, the prior art connections offer small, faying surfaces for centering and reacting to bending moments. Currently the time required to machine the existing geometry of an interior hosel is between 10-20 minutes depending on the set-up time of the machinist. The time and resources to set up the golf club head component for machining adds to the overall costs.

In the current method employed to machine the interior hosel hole geometry a ball end-mill cutter is used. The ball end-mill cutter spirals down the hosel hole in a constant X, Y, and Z axis positioning method which cuts the hosel hole geometry to the finished dimensions. This descending-spiraling method is slow and consequently costly due to the time required for the process.

Summary of the Invention

A novel interior hosel geometry design of the present invention does not adversely affect the mating components used on a shaft nor the operation of a face component tooling or the cost of a raw, unfinished face component. The novel invention reduces the time required to machine the interior hosel surfaces of the face component and thereby increases throughput of the machining process and additionally reduces the cost per golf club head component. This is preferably accomplished by modifying the design of the interior hosel geometry, and the machining methods and cutters employed to finish the interior hosel surfaces to the desired dimensions.

The novel design of the internal geometry of the hosel hole preferably reduces the machining time by 65% or more.

The interior hosel geometry has been modified from three (3) flat triangular notched areas along the sides and bottom of the hosel hole oriented 120 degrees from each other radially around the centerline of the hosel axis to three (3) flat faced ribs protruding into the interior of the hosel hole along the sides and bottom of the hosel hole oriented 120 degrees from each other radially around the centerline of the hosel axis. The novel interior hosel geometry allows for a novel method of finishing the hosel hole geometry. The novel machining method uses a primary cutting process of a form-cutter which is plunged into the hosel hole along the centerline of the hosel (Z- axis of mill) until it reaches the bottom of the hole. The form-cutter finishes all the circular cross-sectional areas of the interior of the hosel hole to final dimensions, then is retracted along the same Z-axis entry path. A secondary machining operation is employed by bringing an angled cutter down the centerline of the hosel hole (Z-axis) to the bottom of the hosel hole then it sweeps across the ribs in an X-Y plane leaving a planar face with the angled cutting face of the angled cutting tool defining the mating surface of the ribs that interface with the IMIX sleeve on the shaft. It is the combination of these two machining operations that greatly reduces the processing time over the current method of machining the interior hosel hole geometry with a ball end-mill cutter.

The novel geometry change of the rib design inside the hosel hole allows the machining operations to operate at a relatively high speed. Form and tapered cutters are used to obtain finished dimensions with a vast reduction in machining time over the previously used ball end-mill cutter method. The novel machining process eliminates the need for 3-axis NC cutting programs.

The novel process for cutting the geometry inside the hosel hole preferably uses Z axis positioning (depth) and then X-Y movements to generate the finished surfaces to the dimensions and tolerances specified.

The protruding flat surface (rib) design as an engagement solution provides both a friction fit based on the ribs tapered angle and the protrusion into the cylindrical hosel hole promotes a greater ease (improved machining time) of finishing with cutting tools. The present invention provides an improved method for producing a club head-shaft connection for cost-effective customization of golf clubs, while providing golfers with golf clubs that provide optimal performance. The connection, which does not require the club head to have a conventional hosel, enables quick and reliable assembly and disassembly of a shaft from the club head.

Description of the Drawings FIG. 1 is a front plan view of a golf club.

FIG. 2 is an exploded top perspective view of the golf club of FIG. 1 illustrating the various components, including a face cup portion of a club head, a shaft, and the connection assembly, which includes a sleeve and a screw-cap.

FIG. 3 is an interior view of a face component and connection assembly of a golf club of FIG. 2 in an assembled state.

FIG. 4 is a cross-sectional view taken generally along the line 4-4 of FIG. 3. FIG. 5 is an enlarged cross-sectional view of a golf club shaft attached via the connection assembly to a hosel of a club head.

FIG. 6A is a top plan view of a face component of a club head. FIG. 6B is a cross-sectional view taken generally along the line A-A of FIG. 6A. FIG. 6C is a cross-sectional view taken generally along the line B-B of FIG.

6B.

FIG. 6D is an enlarged sectional view taken along circle C of FIG. 6B. FIG. 6E is an enlarged sectional view showing greater detail of an upper threaded portion of the hosel.

FIG. 6F is an enlarged isolated sectional view showing greater detail of an upper threaded portion of the hosel. FIG. 6G is an enlarged isolated sectional view showing greater detail of an upper threaded portion of the hosel.

FIG. 6H is an enlarged isolated sectional view showing greater detail of an upper threaded portion of the hosel.

FIG. 7 A is a plan view of a sleeve. FIG. 7B is a cross-sectional view taken generally along the line A-A of FIG.

7A.

FIG. 7C is an enlarged sectional view taken generally along rectangle B of FIG. 7B.

FIG. 7D is an enlarged sectional view taken generally along circle C of FIG. 7B.

FIG. 7E is an enlarged view taken generally along circle G of FIG. 7 A.

FIG. 7F is a cross-sectional view taken generally along the line H-H of FIG. 7A.

FIG. 8 A is a plan view of a screw-cap. FIG. 8B is a top plan view of the screw-cap of FIG. 8 A.

FIG. 8C is a cross-sectional view taken generally along the line A-A of FIG. 8B. FIG. 9A is a plan view of a locking ring, which may be used in the connection assembly.

FIG. 9B is a cross-sectional view taken generally long the line A-A of FIG. 9A. FIG. 1 OA is a perspective view of a ferrule, which may be used in the connection assembly.

FIG. 1OB is a cross sectional view taken generally along the line A-A of FIG. 1OA.

FIG. 1 IA is a plan view of a screw-cap with a polymeric patch. FIG. 1 IB is a plan view of a screw-cap with a polymeric strip.

FIG. 11C is a plan view of a screw-cap with a polymeric pellet. FIG. 12 is a cross-sectional view of the internal hosel geometry of an existing prior art golf club head component.

FIG. 13 is a cross-sectional view of the internal hosel geometry of the present invention golf club head component,

FIG. 14 is a break-out view of the internal hosel geometry of an existing prior art golf club head component.

FIG. 15 is a break-out view of the internal hosel geometry of the present invention golf club head component. FIG. 16 is a back view of a cast face component oriented in a mill.

FIG. 17 is a back view of a cast face component in a mill with a form cutter prepared to be inserted into the hosel to cut the interior surface of the hosel. FIG. 18 is a back view of a cast face component in a mill with an angled side cutter prepared to be inserted into the hosel to cut the interior surface of the hosel.

FIG. 19 is a top view of a face cup with ribs cast integrally into the interior surface of the hosel.

FIG. 20 is a flow chart of the method of the present invention.

Best Mode(s) For Carrying Out The Invention As shown in FIGS. 1-5, a golf club is generally designated 20. Golf club 20 has a club head 22 and a shaft 24 that is coupled to club head 22. Club head 22 is preferably a wood-type golf club head, such as a driver, a fairway wood, or even a hybrid iron- wood-type club, but may also be an iron-type club head. Club head 22 includes a body 26 having a striking face 28, a crown portion 30, a sole portion 32, a heel end 34 and a toe end 36. Striking face 28 generally extends along the front of club head 22 from heel end 34 to toe end 36.

The club head 22 is alternatively a club head such as disclosed in U.S. Patent Number 6758763 for a Multiple Material Golf Club Head, which is hereby incorporated by reference in its entirety. The club head 22 is alternatively a club head such as disclosed in U.S. Patent Number 7166038 for a Golf Club Head, which is hereby incorporated by reference in its entirety.

The club head 22 is alternatively a club head such as disclosed in U.S. Patent Number 7273419 for a Multiple Material Golf Club Head, which is hereby incorporated by reference in its entirety.

The club head 22 is alternatively a club head such as disclosed in U.S. Patent Number 7410428 for a Golf Club Head With A High Moment Of Inertia, which is hereby incorporated by reference in its entirety. Body 26 is preferably composed of a metallic material, such as titanium, titanium alloy, stainless steel, or the like. Alternatively, body 26 may be composed of multiple materials, such as a metal face cup 27 attached to an aft-body composed of a different material, such as a carbon composite material, or a stainless steel body with a carbon composite crown. Body 26 preferably has a hollow interior and includes a hosel 38 for receiving shaft 24. Where body 26 is comprised of a cup face 27 and an aft-body, hosel 38 is provided in cup face 27. Hosel 38 is preferably an internal hosel that extends into body 26 with an opening 40 in crown portion 30. Alternatively, club head 22 may be provided with an external hosel (not shown) rather than an internal one. The shaft 24 is preferably composed of a graphite material, however, the shaft

24 is alternatively composed of a metallic material, such as stainless steel or titanium. Alternatively, the shaft 24 is composed of a hybrid of graphite and metal. The shaft 24 is coupled to club head 22 using a connection assembly 44 that provides for easy assembly, disassembly and reassembly, thereby facilitating customization of golf club 20.

The connection assembly 44 preferably comprises a sleeve 46 and a screw-cap 48. Connection assembly 44 cooperates with hosel 38 of club head 22 to secure shaft 24 to club head 22. Sleeve 46 is mounted on a tip end 50 of shaft 24. Shaft 24 with sleeve 46 mounted thereon is then inserted in hosel 38 of club head 22. Screw-cap 48 secures sleeve 46 to hosel 38 to retain shaft 24 in connection with club head 22.

As best illustrated in FIGS. 6A-6H, hosel 38 is preferably integrally formed with the body of club head 22. For example, club head 22 including hosel 38 may be cast of a suitable metal material, such as titanium alloys, steel alloys, magnesium and aluminum. Hosel 38 preferably has a main opening 58 for receiving a portion of sleeve 46 and shaft 24. Main opening 58 preferably has a depth L _D of at least 1.000 inch, for example 1.065 inch. Hosel 38 includes an upper threaded portion 60 and a lower portion 62.

Upper threaded portion 60 includes a plurality of threads 64, which provide upper threaded portion 60 with a threaded cross-section. As best illustrated in FIGS. 6E-6H, upper threaded portion 60 preferably has a length Lu in the range of 0.350 inch to 0.500 inch. The diameter Du at a top end of upper threaded portion 60 is preferably 0.580 inch. The plurality of threads 64 provided in upper threaded portion 60 preferably includes between one and ten threads, and more preferably between three and eight threads. In one embodiment of the invention, there are five threads 64 in upper threaded portion 60. Threads 64 preferably have a pitch in the range of six and thirty-two, more preferably between eighteen and twenty-eight, and even more preferably between twenty-four and twenty-eight. Threads 64 preferably have a pitch diameter PD in the range of 0.250 inch to 0.750 inch, more preferably in the range of 0.420 inch to 0.630 inch, and even more preferably between 0.530 inch and 0.570 inch.

Lower portion 62 of hosel 38 has a ribbed cross-section, which is best illustrated in FIG. 6C. hi a preferred embodiment of the invention, lower portion 62 has at least ribbed surfaces 66, with a curved region provided between adjacent ribbed surfaces 66. hi addition, lower portion 62 tapers from proximate upper threaded portion 60 to the bottom of hosel 36. By way of example, lower portion 62 may taper from a diameter of 0.517 inch proximate upper threaded portion 60 to a diameter DB of 0.312 inch proximate its bottom end. The taper of lower portion 62 ensures a snug fit between sleeve 46 and hosel 38, when shaft 24 is fully secured to club head 22. Sleeve 46, which is best illustrated in FIGS. 7A-7F, has an aperture 68 formed in an upper end 69 thereof for receiving tip end 50 of shaft 24. Sleeve 46 is fixedly secured to shaft 24 using an adhesive, such as epoxy. Sleeve 46 is preferably comprised of a metal material, such as titanium alloys and aluminum alloys.

Sleeve 46, which preferably has an overall length Ls of at least 1.500 inches, includes a body having a top section 70 and a lower section 72. Top section 70 has an aperture 68 formed therein. Aperture 68 has a diameter DA that complements the outer diameter of tip end 50 of shaft 24. Depth LA of aperture 68 is preferably sufficient to receive at least 1.000 inch of tip end of shaft. In one embodiment of the invention, depth L _A is approximately 1.126 inches. Lower section 72 of sleeve 46 has a multi-faceted exterior surface for engaging lower portion 62 of hosel 38. hi one embodiment of the invention best illustrated in FIG. 7F, lower portion 62 has a pseudo-triangular cross-section with least three outer, planar surfaces 74, which will make contact with respective planar surfaces 66 of hosel 38. Regions between the planar surfaces 74 are curved. At least three sides are preferred to stop rotation, both axially and about a pivot axis that is created when there are fewer than three contact points. Lower section 72 of sleeve 46 is preferably slightly tapered to provide a snug fit in hosel 38. Lower section 72 has a length LL preferably in the range of 0.375 inch to 0.525 inch to provided sufficient contact surface area. When the screw-cap is tightened down on the sleeve, the screw-cap forces the multi-faceted lower section of the sleeve against the mating contact surfaces of the lower portion of the hosel of the golf club head, and all rotation is mechanically prohibited. Lower section 72 of sleeve 46 may be further provided with an opening 76 formed therein to remove excess weight from sleeve 46.

Screw-cap 48, illustrated in FIGS. 8A-8E, is preferably comprised of a lightweight metal material, such as a titanium alloy or an aluminum alloy. Screw-cap 48 includes a body 80 having a central aperture 82. Screw-cap 48 is mounted onto shaft 24 over sleeve 46. Screw cap 48 includes an upper area 84 and a threaded area 86. Threaded area 86 is provided with a plurality of threads 88, which engage threads 64 of upper threaded portion 60 of hosel 38 to secure shaft 24 to club head 22.

As illustrated in FIG. 5, connection assembly 44 may further include a locking ring 54 and a ferrule 52. Locking ring 54, shown in FIG. 9A and FIG. 9B, is preferably a thin metal ring having a thickness T in the range of 0.025 inch to 0.035 inch. Locking ring 54 is mounted in an annular groove 90 (FIGS. 7C and 7E) formed in top section 70 of sleeve 46. Locking ring 54 retains screw-cap 48 loosely on sleeve 46 and prevents screw-cap 48 from completely separating from hosel 38 of club head 22.

Ferrule 52, shown separately in FIG. 1OA and FIG. 1OB, is preferably positioned on shaft 24 above the top section of sleeve 46. Ferrule 52, which may be composed of a lightweight, thermoplastic material, includes a body having a main aperture for receiving shaft 24. Ferrule 52 may further include a plurality of ribs 90 formed on its inside surface for aligning ferrule 52 on shaft 24

Golf club 20 is preferably assembled by placing ferrule 52, screw-cap 48, locking ring 54 and sleeve 46 over tip end 50 of shaft 24. Sleeve 46 is secured to shaft 24 by an adhesive, such as epoxy. Tip end 50 of shaft 24, with sleeve 46 affixed therein, is then inserted into hosel 38 of club head 22. The tapered multi-faceted surface of lower section 72 of sleeve 46 engages with lower portion 62 of hosel 38. Next, screw-cap 48 is slid along tip end 50 of shaft 24, such that its threads 88 engage threads 64 of upper threaded portion 60 of hosel 38. A special tool (not shown) may be provided to ensure that screw-cap 48 is properly tightened with the correct amount of torque. When screw-cap 48 is fully tightened to upper threaded portion 60 of hosel 38, the lower end of screw-cap 48 seats on a ledge 92 of sleeve 46 to prevent sleeve 46, and therefore shaft 24, from separating from club head 22. Locking ring 50 may then be placed in the annular groove 90 of sleeve 46 to prevent screw-cap 48 from fully disengaging from hosel 38. Ferrule 52 is then secured onto shaft 24 and top section 70 of sleeve 46 just above screw-cap 48. hi addition to locking ring 50, a compressible polymeric material may be provided on some or all of the threads 88 of screw-cap 48. Alternatively, the polymeric material may be applied to threads 64 of hosel 38. When mating threads 64 and 88 of hosel 38 and screw-cap 48, respectively, are engaged, the polymeric material is compressed and a counterforce is created. This counterforce creates a stronger contact between the threads of the two components and creates a positive resistance to vibration and loosening. One such material is Nylok available from Nylok Corporation. FIGS. 1 IA-11C show various configurations of Nylok material on screw-cap 48. In FIG. 1 IA, a patch 100 of Nylok material maybe coated over one or more threads 88 of screw-cap 48. Patch 100 may have a height in the range of 0.01 inch to 0.5 inch, more preferably in the range of 0.04 inch to 0.3 inch, and even more preferably in the range of 0.1 inch to 0.2 inch. Patch 100 preferably covers between one-half and ten threads 88, and more preferably between one and five threads 88. Patch 100 may extend completely about one or more threads 88 of screw-cap 48 or only a portion thereof. For example, patch 100 may extend anywhere between 30° and 360° about screw-cap 48. The thickness of patch 100 is preferably between 0.005 inch to 0.050 inch.

In FIG. 1 IB a strip 102 of Nylok material is coated across multiple threads 88 of screw-cap 48. Strip 102 may have a height in the range of 0.01 inch to 0.5 inch, more preferably in the range of 0.04 inch to 0.3 inch, and even more preferably in the range of 0.1 inch to 0.2 inch. The width of strip 102 maybe betweenO.Ol inch and 0.2 inch, more preferably between 0.02 inch and 0.1 inch. Strip 102 preferably has a thickness of 0.03 to 0.15 inch. FIG. 11C illustrates a pellet 104 of Nylok material embedded in threads 88 of screw-cap 48. Pellet 104 may have a diameter of between 0.01 inch and 0.6 inch, more preferably between 0.03 and 0.15 inch. The thickness of pellet 104 is preferably between 0.03 inch and 0.15 inch. FIGS. 12 and 14 show the internal geometry of a hosel of an existing golf club head. FIGS. 13 and 15 show the internal geometry of aliosel of the present invention. FIG. 19 illustrates the face component as cast with ribs in the hosel. FIGS. 16- 18 show the cutting process of the present invention. FIG. 20 is a flow chart of a method 700 of the present invention.