Abstract:
A golf club including a golf club head, a hosel, a ferrule, and a shaft. The hosel defines a cavity having an opening at an upper end of the hosel and an annular recess at an outer surface of the hosel. The ferrule defines an axial bore and has an annual ridge positioned within the axial bore. The ferrule also has a bottom portion that surrounds the upper end of the hosel. The shaft includes an upper end adapted to be gripped by a golfer and a lower end that extends through the axial bore and into the cavity defined by the hosel. The annular ridge and the annular recess engage each other in an interlocking fashion to inhibit rotation and longitudinal movement of the ferrule.

Description:
BACKGROUND OF TH INVENTION 
   The present invention relates generally to golf clubs and, more particularly, a ferrule and hosel geometry for a golf club. 
   Golf clubs include a club head mounted to a tip of a shaft. Typically, the club head includes a cylindrical hosel that defines an opening for receiving the tip of the shaft. It is important that the junction of the hosel and shaft has sufficient strength for the rigors the golf club must endure. Also, abrupt edges at this junction lack esthetic appeal and can be a safety issue. To alleviate such concerns, sleeves positioned about the club shaft, referred to as ferrules, have been used. 
   Ferrules commonly are configured to have a lower portion positioned between the tip of the shaft and the hosel and to have an upper portion snug fit to the shaft. After prolonged use and exposure, such ferrules can loosen about the shaft and inhibit club performance. Alternatively, ferrules can be attached with adhesive to promote durability. However, caution must be taken during assembly to ensure that the ferrule does not separate from or twist about the hosel, particularly prior to setting of the adhesive. During club assembly, ferrules often must be polished by hand to be flush about the diameter of the hosel for a smooth, cosmetic transition between the shaft and the head. This process can be costly and time consuming. 
   It should, therefore, be appreciated that there exists a need for a ferrule for a golf club having improved durability and improved ease of assembly. The present invention fulfills this need and others. 
   SUMMARY OF THE INVENTION 
   The present invention provides a ferrule, and a golf club incorporating same, configured for improved durability and ease of assembly. The ferrule defines an axial bore for receiving a club shaft therethrough. A bottom portion of the ferrule is sized to receive and surround an upper end of a hosel of a club head. The hosel and the ferrule are cooperatively configured to inhibit movement of the ferrule and, preferably, axial rotation and longitudinal movement of the ferrule are both inhibited by engagement of corresponding surfaces of the ferrule and the hosel. 
   In a preferred embodiment, a plurality of protrusions, ribs and/or grooves are provided on an interior surface of the ferrule. More particularly, protrusions at an upper, interior surface of the ferrule body serve to help center the shaft tip within the ferrule body. Also, a lower interior surface of the ferrule can include an annular protrusion that mates with an annular groove defined in by the upper, exterior surface of the hosel. 
   In a detailed aspect of a preferred embodiment, a plurality of ribs at a lower, interior surface of the ferrule are received in corresponding grooves formed on an upper exterior surface of the club head hosel. These ribs serve to locate and initially fix the ferrule onto the hosel of the club head. Alternatively, the grooves may be provided on the ferrule and the ribs on the hosel. Preferably, a chamfer is provided at an exterior surface of a lower end of the ferrule. 
   In another preferred embodiment, the hosel includes an outer surface having at least one strut configured to inhibit axial rotation of the ferrule. Preferably, the strut has a knife-like edge configured to cut into the interior surface of the ferrule, thereby inhibiting axial rotation. 
   In a preferred method of assembly, savings in time and labor are achieved in that a ferrule may be provided on either the head or shaft prior to shipping by a vendor, excess adhesive is simply wiped off the club during final assembly and because of the net fit no grinding is required to match the ferrule and hosel diameters, thus preserving cosmetic features on the ferrule. 
   For purposes of summarizing the invention and the advantages achieved over the prior art, certain advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein. 
   All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment disclosed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the present invention will now be described, by way of example only, with reference to the following drawings in which: 
       FIG. 1  is a cross-sectional view of a golf club in accordance with the invention, depicting a ferrule at a junction of a club shaft and hosel portion of a club head. 
       FIG. 2  is a cross-section view taken along line A—A of the golf club of  FIG. 1 , depicting protrusions of the ferrule in contact with the shaft. 
       FIG. 3  is a cross-sectional view taken along line B—B of the golf club of  FIG. 1 , depicting a conforming interface between the ferrule and hosel. 
       FIG. 4  is a close-up perspective view of the hosel portion of the club head of  FIG. 1 . 
       FIG. 5  is a cross-sectional view the hosel portion of the club head of  FIG. 1 . 
       FIG. 6  is a perspective view of the ferrule of  FIG. 1 . 
       FIG. 7  is a cross-sectional view of the ferrule of  FIG. 1 . 
       FIG. 8  is a cross-sectional view a ferrule in another embodiment in accordance with the invention. 
       FIG. 9  is a perspective view of a hosel portion corresponding to the ferrule of  FIG. 8 . 
       FIG. 10  is a cross-sectional view of the hosel of  FIG. 9 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   With reference to the illustrative drawings, and particularly to  FIG. 1 , there is shown a junction portion of a golf club  10  in which a club shaft  12  and a hosel  14  are received within a bore  16  of a ferrule  18 . The ferrule includes an upper portion  22  positioned about the shaft and a lower portion  24  positioned about an end  26  of the hosel. The upper portion includes protrusions  28  that serve to align the shaft within the bore of the ferrule. The lower portion of the ferrule is configured to cooperatively engage the end of the hosel such that the ferrule is securely affixed to the hosel and, to that end, the ferrule includes an annular ridge  30  adjacent to a lower opening  32  ( FIG. 7 ) of the bore. The ridge engages a recessed portion  34  of the hosel, maintaining the ferrule in place. The lower edge  36  of the ferrule preferably is chamfered or rounded to facilitate installation onto the hosel. Moreover, the lower portion of the ferrule and the end of the hosel are cooperatively configured to inhibit axial rotation of the ferrule. 
   With reference to  FIG. 2 , the protrusions  28  at the upper portion  22  of the ferrule aid in centering the shaft within the bore  16  providing a cavity  40 . The cavity facilitates a flow of adhesive between the shaft, hosel and ferrule, thereby promoting a secure and durable bond amongst these components. During assembly, excess adhesive can flow past the protrusions and out an upper opening  42  ( FIG. 7 ) of the bore, as needed. Thereafter, excess adhesive can simply be wiped off. Although the present embodiment employs three protrusions, other embodiments having different numbers of protrusions and having protrusion of different configurations are contemplated. 
   With reference now to  FIG. 3 , the lower portion  24  of the ferrule and the end  26  of the hosel cooperatively engage to inhibit rotation of the ferrule about the hosel. More particularly, the ferrule further includes a plurality of ribs  44  longitudinally aligned about an interior surface  46  and positioned above the annular ridge  30  ( FIG. 7 ). The ribs are received in corresponding grooves  48  formed on an upper exterior surface of the hosel. In this manner, the hosel and the ferrule cooperative to inhibit axial rotation of the ferrule, this facilitates assembly and the setting of the adhesive. In the exemplary embodiment, the ribs are positioned above the annular ridge. Other structural configurations can be employed to inhibit axial rotation of the ferrule. For example, the ribs and corresponding grooves can be positioned below or incorporated into the annular ridge and the annular recess  34 , respectively. 
   With reference to  FIGS. 4 and 5 , the hosel  14  is generally cylindrical having a centered bore  41  sized to receive the shaft  16 . In this embodiment, the hosel bore has a diameter D b  of about 9.6 mm at the upper portion  22  thereof. The hosel bore is defined by an interior surface  50  that includes a tapered portion  54  proximate to the opening into the bore. This tapered portion aids in receiving the shaft into the bore as well as facilitating adhesive flow. As best shown in  FIG. 1 , even with the shaft in place, the tapered portion affords adhesive flow therein. 
   The end  26  of the hosel includes a locking rim  38 , defining the longitudinal grooves  48  ( FIG. 4 ) spaced there about. The rim further serves to restrict longitudinal movement of the ferrule  18  by interacting with the ridge  30  ( FIG. 7 ). In this embodiment, the hosel has an outer diameter D 1  of about 11.63 mm at the rim. Continuing down the outer surface  52  of the hosel, the rim leads to the recessed portion  34 , which in this embodiment has an outer diameter D 2  of about 11.48 mm. Following the recessed portion the outer surface extends laterally out, defining an annular edge that cooperates with the chamfered edge  36  ( FIG. 1 ) of the ferrule to provide a smooth transition seam between the hosel and the ferrule. 
   With reference to  FIGS. 6 and 7 , the bore  18  of the ferrule has a variable inner diameter profile, including a minimum diameter sufficient to receive the club shaft. At the ridge  30  of the ferrule, an inner diameter D 3  is provided, less than both the outer diameter D 1  and D 2  of the hosel. Here, inner diameter D 3  is about 11.35 mm. Thus, in this embodiment, the ferrule deflects as the ridge passes the locking rim  38  of the hosel and securely engages the outer surface of the hosel. The ferrule is provided with an exterior surface  50  ( FIG. 5 ) that is smoothly tapered across its longitudinal length, providing an aesthetic and functional transition between the club head and the shaft. The exterior surface can be provided with concave regions and/or raised regions to provide identifying indicia on the ferrule. The ferrule  18  is formed of a lightweight yet durable material, e.g., nylon, polycarbonate, and polyoxymethylene. Materials having a density less than about 2 g/cc and a modulus of elasticity no greater than about 3 GPa have been found to be effective. Optionally, a colorant can be added to the material. In the exemplary embodiment, the ferrule is formed of an acetal resin compound commonly known as Delrin®, from E.I. du Pont de Nemours and Co. 
   Alternative embodiments of a hosel  114  and a ferrule  118  are shown in  FIGS. 8–10 , with like numerals referring to like elements. With reference to  FIG. 8 , the ferrule  118  may be substantially the same as shown in  FIG. 7 , absent the plurality of ribs  44  about the annular ridge  30 . In place of the ribs  44  on the ferrule being received in corresponding grooves formed in the hosel, longitudinal struts  60  shown in  FIGS. 9–10  are provided on the recessed portion  34  of the hosel  114  to inhibit axial rotation of the ferrule. The struts are relatively thin and form knife-like edges that cut into annular ridge of the ferrule to inhibit axial rotation thereof. A single strut or a plurality of struts may be provided, as desired. The preferred embodiment shown in  FIGS. 9–11  has four struts equally spaced about the hosel. 
   With reference again to  FIG. 1 , the golf club  10  is configured for easy assembly. In an exemplary approach, the ferrule  18  is pre-positioned on either the head or the shaft  12 . The ferrule can be positioned even prior to shipment of either the head or the shaft by a vendor. Adhesive is applied in the opening of the hosel, and the tip of shaft is then inserted. In addition or alternatively, adhesive can be applied directly to the shaft and/or the ferrule prior to insertion. Regardless of the approach, the cavity  40  ( FIG. 2 ) defined therein enables effective flow of the adhesive amongst the components. Excess adhesive can exit the cavity, allowing it to be wiped off. The ferrule is positioned over the upper end of the hosel, such that the annular ridge  30  of the ferrule is received within the annular recess of the hosel. Once positioned, axial rotation of the ferrule is inhibited, which facilitates the setting of the adhesive. 
   It should be appreciated from the foregoing that the present invention provides a ferrule, and a golf club incorporating same, configured for improved durability and ease of assembly. The ferrule defines an axial bore for receiving a club shaft therethrough. A bottom portion of the ferrule is sized to receive and surround an upper end of a hosel of a club head. The hosel and the ferrule are cooperatively configured to inhibit movement of the ferrule. In a preferred embodiment, axial rotation and longitudinal movement of the ferrule are both inhibited by engagement of corresponding surfaces of the ferrule and the hosel. Alternatively, the hosel may include at least one strut having a knife-like edge configured to cut into the interior surface of the ferrule, thereby inhibiting axial rotation. The ferrule can be provided with protrusions. 
   Although the invention has been disclosed in detail with reference only to the preferred embodiments, those skilled in the art will appreciate that additional ferrules and golf club incorporating same can be included without departing from the scope of the invention. Accordingly, the invention is defined only by the claims set forth below.