Method and apparatus for assembling a shaft to a golf club head and a golf club having such assembly

Information

  • Patent Grant
  • 6652388
  • Patent Number
    6,652,388
  • Date Filed
    Wednesday, January 29, 2003
    21 years ago
  • Date Issued
    Tuesday, November 25, 2003
    21 years ago
Abstract
A method and apparatus for assembling a shaft to a golf club head is disclosed. The club head is positioned in a club head alignment device of the apparatus, which further includes a holding device and a press device with a jaw mechanism. A ferrule and a sleeve are placed on the tip end of the shaft, and the butt end is inserted into the holding device. The tip end of the shaft and the sleeve are inserted into a tapered bore in the hosel of the club head. The jaw mechanism of the press device is then enclosed around the shaft, and the press device is operated to force the sleeve further into the tapered hosel bore. The club head and partially attached shaft are then removed from the apparatus, and the ferrule is secured to the hosel to completely attach the shaft.
Description




CROSS REFERENCE TO RELATED APPLICATIONS




Not Applicable




FEDERAL RESEARCH STATEMENT




Not Applicable




BACKGROUND OF INVENTION




1. Field of the Invention




The present invention relates to assembling shafts to golf club heads. More specifically, the present invention relates to a method and apparatus for assembling and securing a shaft to a golf club head.




2. Description of the Related Art




The game of golf has benefited greatly from technological advancements throughout its glorious history. Examples include the progression of golf balls from a leather featherie version to the gutta percha version to the dimpled version to the two-piece and three-piece versions of today. Another example of the technological advancement of golf is the progression of the shaft from wood to metal to graphite to the hybrid versions of today. Yet another example of the technological advancement of golf is the progression of woods from persimmon to steel to titanium to the advanced materials of today. All of these advancements have greatly improved the game of golf for golfers everywhere. However, the game of golf is still requires a golf club with a shaft connected to a golf club head in order to strike a golf ball.




The attachment of the shaft to the golf club head requires securing the shaft to the golf club head in a manner that withstands the tremendous forces exerted during swinging and impact with a golf ball. The attachment mechanism could encompass compressive forces, chemical adhesion and/or mechanical means. One preferred manner for attaching a shaft to a metal wood has been the use of an epoxy to secure the shaft within a hosel. This attachment procedure is usually performed manually, with an operator overcoating a tip end of a shaft with epoxy, and then inserting the shaft into the hosel wherein excess epoxy (2 to 4 grams) is flushed onto the golf club head. In a through-bore golf club head, the tip end of the shaft extends through the bore in the sole of the golf club head and is cut during the assembly process. This attachment procedure is wasteful (excess shaft material and epoxy) and detrimental to the operator if performed continuously throughout the day. The current procedure also requires the step of sand blasting the hosel to create a better adhesive surface for the epoxy. Further, such an attachment procedure typically requires heating the golf club in an oven for two hours to cure the epoxy and completely secure the shaft to the golf club head. Such ovens require great amounts of floor space in a factory, and use excessive amounts of energy. In addition, the epoxy may not be evenly dispersed between the shaft and the hosel, leaving voids which would adversely affect the bond between the shaft and the golf club head. Thus, there is a need for an improvement in the attachment of a shaft to a golf club head.




SUMMARY OF INVENTION




The present invention provides a solution to the wastefulness and other problems of attaching a shaft to a golf club head. The present invention is able to accomplish this by providing a method and apparatus that eliminates the need for an adhesive or epoxy to secure a shaft to a golf club head, which reduces production time while simplifying the procedure for an operator.




One aspect of the present invention is an apparatus for assembling a shaft to a golf club head. The golf club head has a hosel with a tapered bore. The shaft has a tip end and a butt end. A sleeve and a ferrule are disposed on the shaft. The apparatus includes an upper section and a lower section, a club head alignment device, a holding device, and a press device including a jaw mechanism. The club head alignment device is disposed on the lower section of the frame and receives the golf club head. The holding device receives the butt end of the shaft and is disposed on the upper section of the frame. The holding device is also capable of vertical oscillation. The press device is disposed on the lower section of the frame and is capable of vertical oscillation. The press device has a cavity for receiving the shaft with the ferrule disposed thereon. The jaw mechanism of the press device is capable of enclosing the shaft above the sleeve and forcing the sleeve into the tapered hosel bore of the golf club head during oscillation of the press device.




Another aspect of the present invention is a method for assembling a shaft to a golf club head. The golf club head has a hosel with a tapered bore. The shaft has a tip end and a butt end. The method begins with positioning the golf club head in a club head alignment device of an assembly apparatus. Next, a ferrule and a sleeve are placed on the shaft proximate the tip end. The butt end of the shaft is then positioned into a holding device of the assembly apparatus. Next, a portion of the tip end of the shaft and a portion of the sleeve are placed into the tapered bore of the hosel of the golf club head. A jaw mechanism of the press device then encloses around a portion of the shaft between the sleeve and the ferrule. Next, the press device moves to engage a top end of the sleeve and force the sleeve into the tapered bore of the hosel of the golf club head to create a golf club head with partially attached shaft. When the press device moves away from the golf club head, the jaw mechanism disengages. Next, the golf club head with the partially attached shaft is removed from the assembly apparatus. Finally, the ferrule is secured to the hosel to create a golf club head with a completely attached shaft.




Still another aspect of the present invention is a golf club including a golf club head and a shaft. The golf club head may be a wood-type or an iron-type golf club head. The golf club head includes a hosel having a tapered bore. A tip end of the shaft with a tapered sleeve disposed thereon is inserted into the tapered bore of the hosel. The golf club further includes a ferrule secured to the hosel to retain the sleeve and shaft in place.




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 DRAWINGS





FIG. 1

is a side perspective view of a preferred embodiment of the apparatus.





FIG. 1A

is an enlarged view of circle A of FIG.


1


.





FIG. 2

is a front perspective view of the apparatus of FIG.


1


.





FIG. 2A

is an enlarged view of circle A of FIG.


2


.





FIG. 3

is a side view of the apparatus of

FIG. 1

with a golf club head and shaft in a pre-pressing position.





FIG. 3A

is an enlarged cross-sectional view

FIG. 3

along line A—A.





FIG. 4

is a side view of the apparatus of

FIG. 1

with a golf club head and shaft in a post-pressing position.





FIG. 4A

is an enlarged cross-sectional view

FIG. 4

along line A—A.





FIG. 5

is an isolated view of a wood-type golf club head.





FIG. 5A

is a cross-sectional view of the wood-type golf club head of

FIG. 5

along line A—A.





FIG. 6

is an exploded view of a wood-type golf club.





FIG. 7

is a front view of a wood-type golf club.





FIG. 7A

is a cross-sectional view of the wood-type golf club head of

FIG. 7

along line E—E.





FIG. 8

is an isolated view of an iron-type golf club head.





FIG. 8A

is a cross-sectional view of the iron-type golf club head of

FIG. 8

along line A—A.





FIG. 9

is an exploded view of an iron-type golf club.





FIG. 10

is a front view of an iron-type golf club.





FIG. 10A

is a cross-sectional view of the iron-type golf club head of

FIG. 10

along line A—A.





FIG. 11

is an isolated perspective view of a retention nut.





FIG. 12

is a bottom plan view of the retention nut of FIG.


11


.





FIG. 13

is a side view of the retention nut of FIG.


11


.





FIG. 14

is an isolated perspective view of a sleeve for use with a wood-type golf club head.





FIG. 15

is a side view of the sleeve of FIG.


14


.





FIG. 16

is an opposite side view of the sleeve of FIG.


15


.





FIG. 17

is a top plan view of the sleeve of FIG.


14


.





FIG. 18

is an isolated perspective view of a sleeve for use with an iron-type golf club head.





FIG. 19

is a side view of the sleeve of FIG.


18


.





FIG. 20

is an opposite side view of the sleeve of FIG.


19


.





FIG. 21

is a top plan view of the sleeve of FIG.


18


.





FIG. 22

is a perspective view of a ferrule for use with a wood-type golf club head.











DETAILED DESCRIPTION




As shown in

FIGS. 1

,


1


A,


2


and


2


A, an assembly apparatus is generally designated


30


. The apparatus


30


preferably has an upper section


31


and a lower section


32


. The apparatus


30


preferably has an elongated bar


33


connected to a base


34


. The elongated bar


33


will generally have a length corresponding to the length of a shaft, which varies depending on the golf club (generally 30 to 52 inches). The apparatus


30


is preferably composed of a metal material, such as aluminum.




The apparatus


30


is constructed for the attachment of a shaft to a golf club head without the use of an epoxy or other adhesive to secure the shaft to the hosel of the golf club head. The apparatus


30


preferably includes a club head alignment device


35


for positioning a club head in the apparatus


30


for attachment of a shaft thereto. The apparatus


30


also preferably includes a holding device


36


disposed in the upper section


31


of the apparatus


30


. The holding device


36


, which is movable in a vertical direction with respect to the club head alignment device


35


, retains the shaft during the attachment process. The apparatus


30


also preferably includes a press device


37


disposed in the lower section


32


of the apparatus


30


. The press device


37


assists in attaching the shaft to the golf club head through use of a jaw mechanism


40


, which has first and second jaws


41




a


and


41




b


. The press device


37


preferably includes an open cavity


45


in a main member


46


, which is connected to the base


34


by a pair of stanchions


44




a


and


44




b


. The cavity


45


, which is preferably approximately 4 inches in length, is open on a front surface


47


of the main member


46


. The main member


46


preferably oscillates in a vertical direction within a set a range (preferably 0.5 inch to 3 inches) along the stanchions


44




a


and


44




b.






The holding device


36


preferably includes a retaining member


48


with an aperture (not shown) for receiving the shaft. The retaining member


48


holds the shaft during operation of the press device


37


as discussed below.




The club head alignment device


35


has a projection base


42


with a projection


43


thereon for retaining and aligning the golf club head within the apparatus


30


. Those skilled in the pertinent art will recognize that other means may be used for aligning the golf club head within the apparatus


30


without departing from the scope and spirit of the present invention.




The apparatus


30


also preferably includes a lateral arm


38


connected to the elongated bar


33


. The lateral arm


38


has a shaft alignment device


39


for aligning the shaft graphics with the face of the golf club head. The shaft alignment device


39


is preferably a laser alignment device, such as a Mini Laser Line


1049


with Industrial Housing available from H-W Fairway International, Inc. of Kent, Ohio.




Referring to

FIGS. 5

,


5


A and


6


, a wood-type golf club head


50


has a hosel


52


with a tapered bore


54


. The tapered bore


54


has an upper portion


56


and a lower portion


58


, wherein the diameter of the bore


54


tapers from the upper portion


56


to the lower portion


58


. In a preferred embodiment, the upper portion


56


has a diameter D that ranges from 0.25 inch to 0.625 inch, and the lower portion


58


has a diameter D′ that ranges from 0.25 inch to 0.50 inch, with the upper portion diameter D being greater than the lower portion diameter D′ such that the upper portion


56


of the tapered bore


54


preferably has about a 1° taper on each side, or about a 2° included taper. The golf club head


50


preferably has an interior hosel


52


, however, those skilled in the pertinent art will recognize that external hosel golf club heads are well within the scope and spirit of the present invention. One example of a golf club head


50


with an interior hosel is the STEELHEAD PLUS® driver available from the Callaway Golf Company of Carlsbad, Calif. With a golf club head


50


with an interior hosel


52


, the golf club head


50


preferably has a crown opening


60


and a sole opening


62


for accessing the tapered bore


54


. In a preferred embodiment of the invention, the upper portion


56


of the tapered bore


54


of the hosel


52


has a threaded portion (not shown) for receiving a retention nut, as described below.




A shaft


70


has a tip end


72


, which is inserted into the hosel


52


of the golf club head


50


. The shaft


70


may be composed of a stainless steel or a graphite material. A ferrule


84


, a retention nut


82


and a sleeve


80


are placed over the tip end


72


of the shaft


70


. The sleeve


80


is then inserted with the tip end


72


of the shaft


70


into the tapered bore


54


as described below. The retention nut


82


is then threaded into the hosel


52


, and the ferrule


84


threaded onto the retention nut


82


, as described below.




Referring now to

FIGS. 3 and 3A

, the golf club head


50


is positioned on the golf club head alignment device


35


by placing the hosel


52


over the projection


43


. Next, the shaft


70


, with the ferrule


84


, retention nut


82


and sleeve


80


placed over the tip end


72


, is positioned within the holding device


36


by inserting a butt end


74


of the shaft


70


into the aperture (not shown) of the retaining member


48


. The holding device


36


is then moved along the elongated bar


33


away from the the golf club head alsignment device


35


. Those of ordinary skill in the art will recognize that although the assembly apparatus


30


is illustrated in a vertical orientation, other orientations, such as horizontal, may also be used.




Next, a portion of the shaft


70


with the ferrule


84


and the retention nut


82


are placed within the cavity


45


of the press device


37


. The sleeve


80


and the tip portion


72


of the shaft


70


are then inserted into the tapered bore


54


of the hosel


52


of the golf club head


50


, which is positioned in the golf club head alignment device


35


. A portion of the sleeve


80


extends above the crown opening


60


of the golf club head


50


. Next, the jaws


41




a


and


41




b


of the jaw mechanism


40


enclose about a portion of the shaft


70


below the retention nut


82


and above the sleeve


80


. In a preferred embodiment of the invention, the jaws


41




a


and


41




b


do not engage the shaft. Preferably, the bottom of each of the jaws


41




a


and


41




b


engages the top surface of the sleeve


80


. Next, the press device


37


moves toward the golf club head


50


to force the sleeve


80


further into the tapered bore


54


as shown in

FIGS. 4 and 4A

. Approximately 3800 pounds of force are used to insert the sleeve


80


in the tapered bore


54


. The press travels between approximately 0.25 inch and 1.00 inch toward the club head alignment device


35


. The decreasing diameter of the tapered bore


54


collapses the sleeve


80


around the shaft


70


, thereby retaining the shaft


70


within the tapered bore


54


of the hosel


52


of the golf club head


50


without the use of an epoxy or other adhesive.




The golf club head


50


with the partially attached shaft


70


is then removed from the apparatus


30


. Next, the retention nut


82


is threaded into the hosel


52


to provide an additional means of securing the sleeve


80


within the tapered bore


54


. The ferrule


84


may then be threaded onto the retention nut


82


or the hosel


52


to completely attach the shaft


70


to the golf club head


50


.

FIGS. 7 and 7A

illustrate the golf club head


50


with the shaft


70


completely attached. Those of ordinary skill in the art will appreciate that the retention nut


82


is an optional element, providing additional assurance that the sleeve is secured in the tapered bore


54


. If a retention nut is not used, then the ferrule


84


is secured within the tapered bore


54


of the hosel


52


.




The assembly apparatus


30


may also be used to attach a shaft to an iron-type golf club head. Referring to

FIGS. 8

,


8


A and


9


, an iron-type golf club head


50


′ has a hosel


52


′ with a tapered bore


54


. The tapered bore


54


has an upper portion


56


and a lower portion


58


, wherein the diameter of the bore


54


tapers from the upper portion


56


to the lower portion


58


. In a preferred embodiment, the upper portion


56


has a diameter D that ranges from 0.25 inch to 0.625 inch, and the lower portion


58


has a diameter D′ that ranges from 0.25 inch to 0.50 inch, with the upper portion diameter D being greater than the lower portion diameter D′ such that the upper portion


56


of the tapered bore


54


preferably has about a 1° taper on each side, or about a 2° included taper. One example of a golf club head


50


′ is the STEELHEAD® X-14® iron available from the Callaway Golf Company of Carlsbad, Calif. The golf club head


50


′ preferably has a crown opening


60


and a sole opening


62


for accessing the tapered bore


54


. The upper portion


56


of the tapered bore


54


of the hosel


52


′ has a threaded portion (not shown) for receiving a retention nut, as described below.




A shaft


70


has a tip end


72


, which is inserted into the hosel


52


′ of the golf club head


50


′. A ferrule


84


′, a retention nut


82


and a sleeve


80


′ are placed over the tip end


72


of the shaft


70


′. The sleeve


80


′ is then inserted with the tip end


72


of the shaft


70


′ into the tapered bore


54


in the same manner as described above with respect to the wood-type golf club head


50


.




After the assembly apparatus


30


has been used to partially attach the shaft


70


′ to the golf club head


50


′, the golf club head


50


′ with the partially attached shaft


70


′ is removed. The retention nut


82


is then threaded into the hosel


52


′, and the ferrule


84


′ is secured to either the retention nut


82


or the hosel


52


′. As discussed above with respect to the wood-type golf club head


50


, the retention nut


82


may be omitted.

FIGS. 10 and 10A

illustrate the golf club head


50


′ with the shaft


70


completely attached.




The present invention provides a golf club with a shaft securely attached to the club head without the use of epoxy. A pull test was performed on several golf clubs assembled in accordance with the present apparatus and method. For this test, the shaft of each golf club is cut between 4 inches and 5 inches above the club head, and a pin is inserted into the shaft. The golf club head is then mounted in a fixture to prevent movement of the club head during the test. First and second clamps are respectively fastened to the pin and the lower end of the shaft proximate the club head. The first clamp is coupled to a transducer, which measures the force required to remove the shaft from the head. The golf clubs of the present invention all recorded a pull force of greater than 2000 lbs. to remove the shaft from the club head. The present invention preferably produces golf clubs with a pull force of within the range of 2000 lbs. and 4000 lbs.





FIGS. 11-13

illustrate the retention nut


82


in greater detail. The retention nut


82


includes a cylindrical body


92


. The cylindrical body


92


has a length Lr that ranges preferably from 0.15 inch to 0.30 inch, more preferably from 0.18 inch to 0.25 inch, and most preferably approximately 0.21 inch. The cylindrical body


92


may have an outer diameter Dr preferably between 0.4 inch and 0.55 inch, and more preferably approximately 0.47 inch, and an inner diameter D′r preferably between 0.30 inch and 0.45 inch, and more preferably approximately 0.37 inch. The retention nut


82


has an external thread


93


for engaging the threaded portion of the upper portion


56


of the tapered bore


54


. Diametrically opposed notches


94




a


and


94




b


are formed in the cylindrical body


92


at one end and are designed to receive a tool, such as a spanner wrench, for installing the retention nut


82


. Notches


94




a


and


94




b


may have a width Wn of approximately 0.125 inch and a depth Dn of approximately 0.060 inch.





FIGS. 14-17

illustrate the sleeve


80


for use with the wood-type golf club head


50


in greater detail. The sleeve


80


includes a generally cylindrical body


85


having a length Ls


1


preferably between 0.50 inch and 2.0 inches, more preferably between 0.70 inch and 1.0 inch, and most preferably approximately 0.860 inch. The cylindrical body


85


of sleeve


80


preferably has an included taper of approximately 2°, with about a 1° taper on each side. The tapered cylindrical body


85


preferably has an outer diameter Ds


0


at its widest end of preferably between 0.35 inch and 0.50 inch, and more preferably approximately 0.407 inch, and an inner diameter Ds


1


of preferably between 0.25 inch and 0.40, and more preferably approximately 0.348 inch. The sleeve


80


has a first slit


86


and a second slit


88


that enable sleeve


80


to close around the shaft


70


within the hosel


52


. Those of ordinary skill in the art will appreciate that any number of slits may be used. The first slit


86


extends along the entire length Ls


1


of the cylindrical body


85


, while the second slit


88


extends along the majority of the length Ls


1


. The second slit


88


has a length Ls


2


of preferably between 0.60 inch to 0.85 inch, and more preferably about 0.752 inch. Each of the first and second slits


86


and


88


has a width Ws of preferably between 0.02 inch and 0.06 inch, and more preferably approximately 0.03 inch. The sleeve


80


is preferably composed of a metal material, such as aluminum, stainless steel, or titanium, but, alternatively, may be composed of a plastic material, such as a polyamide.





FIGS. 18-21

illustrate the sleeve


80


′ for use with the iron-type golf club head


50


′ in greater detail. The sleeve


80


′ includes a generally cylindrical body


85


′ having a length L′s


1


preferably between 0.30 inch and 1.5 inches, more preferably between 0.50 inch and 1.0 inch, and most preferably approximately 0.60 inch. The cylindrical body


85


′ of sleeve


80


′ preferably has an included taper of approximately 2°, with about a 1° taper on each side. The tapered cylindrical body


85


′ preferably has an outer diameter D′s


0


at its widest end of preferably between 0.375 inch and 0.55 inch, and more preferably approximately 0.455 inch, and an inner diameter D′s


1


of preferably between 0.27 inch and 0.45 inch, and more preferably approximately 0.375 inch. The sleeve


80


′ has a first slit


86


′ and a second slit


88


′ that enable sleeve


80


′ to close around the shaft


70


within the hosel


52


′. Alternatively, a single slit or more than two slits may also be used. The first slit


86


′ extends along the entire length L′s


1


of the cylindrical body


85


′, while the second slit


88


′ extends along the majority of the length L′s


1


. The second slit


88


has a length L′s


2


of preferably between 0.30 inch and 0.50 inch, and more preferably about 0.417 inch. Each of the first and second slits


86


′ and


88


′ has a width W′s of preferably between 0.02 inch and 0.06 inch, and more preferably approximately 0.03 inch. Like sleeve


80


, sleeve


80


′ is preferably composed of a metal material, such as aluminum, stainless steel, or titanium, but, alternatively, may be composed of a plastic material, such as a polyamide.





FIG. 22

illustrates the ferrule


84


for use with the wood-type golf club head


50


in greater detail. The ferrule


84


provides added support to the shaft


70


during a golf swing. The ferrule


84


includes a body


100


having a threaded portion


102


for engagement with the retention nut


82


. Although not illustrated, the ferrule


84


′ for use with the iron-type golf club head


50


′ also a threaded portion for engagement with the retention nut


82


.




From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims. For example, the orientation of the assembly apparatus


30


need not be vertical, but may also be horizontal. In addition, the press device


37


is not required to have a cavity. Therefore, the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims.



Claims
  • 1. A golf club comprising:a golf club head including a hosel having a tapered bore; a shaft having a tip end inserted into the tapered bore of the hosel; a tapered sleeve disposed on the tip end of the shaft in the tapered bore of the hosel, the sleeve composed of a metal, and the sleeve having at least one slit; and a retention nut disposed on the shaft between the sleeve and a ferrule, and the retention nut secured in the tapered bore.
  • 2. The golf club according to claim 1, wherein the golf club head is a wood-type golf club head.
  • 3. The golf club head according to claim 2, wherein the hosel is an interior hosel having a crown opening and a sole opening.
  • 4. The golf club head according to claim 1, wherein the golf club head is an iron-type golf club head.
  • 5. The golf club head according to claim 1, wherein the ferrule has a threaded portion for engagement with the hosel.
  • 6. The golf club according to claim 1, wherein the sleeve has a length ranging from 0.5 inch to 2.0 inches.
  • 7. The golf club according to claim 1, wherein the shaft is composed of a graphite material.
  • 8. The golf club according to claim 1, wherein the shaft is composed of a stainless steel material.
  • 9. The golf club according to claim 1, wherein the ferrule is coupled to the retention nut.
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