CROSS REFERENCE TO RELATED APPLICATIONS
The Present Application claims priority to U.S. Provisional Patent Application No. 61/102,289, filed on Oct. 2, 2008, which is hereby incorporated by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
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OF THE INVENTION
1. Field of the Invention
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.
2. Description of the Related Art
In 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. In 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. Pat. 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. Pat. 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. Pat. 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.
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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.
Having briefly described the present invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS 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.