Golf club with non-circular shaft

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.

FIELD OF THE INVENTION 
The present invention relates to sporting equipment and more particularly 
to golf clubs. 
BACKGROUND OF THE INVENTION 
It is well known that the distance that a golf ball travels when struck 
with the club head of a golf club is a function of club head speed. Golf 
club shafts are typically made of thin walled metal tubing or fiber 
reinforced plastics and composites. Prior art shafts are typically 
fabricated of steel or composite materials such as graphite and are 
typically tapered so as to have a larger circular cross section near the 
handle end of the shaft than at the shaft end adjacent the club head. 
In recent years, companies have manufactured golf clubs which have shafts 
fabricated of composite materials which are light yet strong and flexible. 
The flexibility of the shaft allows the shaft to bend during the swing. 
Such flexing of the shaft during the swing permits the club head to impact 
the ball with a higher velocity and thus propel the ball a greater 
distance. It is understood however, that a golf club shaft which is too 
flexible, can result in club head flutter during the swing. Such flutter 
makes it more difficult to strike the ball in the center of the club head. 
Additionally, twisting of the club head even a small amount can produce 
inaccurate shots. Such problems are particularly notable in the more 
flexible golf club shafts fabricated of composite materials such as 
graphite. 
SUMMARY OF THE INVENTION 
The presently described golf club includes a shaft having a grip receiving 
portion, a shaft mid-section and a hosel mounting portion. A grip is 
disposed over the grip receiving portion of the club and the hosel 
mounting portion of the shaft is mounted to the hosel of a golf club head. 
At least the mid-section of the presently described shaft has a 
non-circular cross section, with a first dimension (measured at the widest 
point) in the direction of ball impact and a second dimension (measured at 
the widest point) in the direction transverse to the direction of ball 
impact. The first dimension is less than the second dimension so that the 
shaft is more flexible in the direction of ball impact than in the 
direction transverse to ball impact. The cross section herein described 
extends at least from below the grip receiving portion to a point adjacent 
the hosel mounting portion near the lower end of the shaft and may extend 
the length of the shaft. Additionally, the shaft may be tapered so as to 
be of larger cross section in the region of the shaft mid-section adjacent 
the grip receiving portion than in the region of the mid-section adjacent 
the hosel mounting portion. In one embodiment the shaft has a cross 
section which is generally oval along a substantial portion of its length, 
with the smaller dimension of the oval oriented in the direction of ball 
travel. Any non-circular cross section may be employed which meets the 
above described criteria to provide a desired flex characteristic. The 
shaft having the presently disclosed cross section permits the golf ball 
to be impacted by the club head at a high club head velocity so as to 
achieve longer shots with both woods and irons while affording greater 
accuracy. 
In a putter, in which increased stiffness is desirable, but flutter is not 
of concern, the shaft may have a non-circular cross section which is 
oriented such that the larger cross section dimension is in the direction 
of ball impact. A light but rigid shaft may thus be provided.

DETAILED DESCRIPTION OF THE DRAWINGS 
A prior art golf club, and in particular an iron 10 is shown in FIG. 1. The 
iron 10, includes a shaft 12 of circular cross section. The shaft includes 
an grip receiving portion 14 which receives a grip 16, a shaft mid-section 
18 and a hosel mounting portion 20. The hosel mounting portion 20 is 
mounted to a hosel 22 of a club head 24 by affixing the hosel mounting 
portion of the shaft 12 to the hosel 22 of the club head 24. The hosel 
mounting portion may be cemented within a cavity disposed in the hosel via 
use of epoxy or any other suitable adhesive. Alternatively, the hosel 
mounting portion of the shaft may be mounted to the hosel via any other 
suitable mounting technique known in the art. 
Referring to FIGS. 2 and 3, the improved golf club 26 is intended for 
hitting a golf ball a considerable distance through the air. Although the 
golf club 26 is depicted as an iron, such may be either a wood or an iron 
(herein referred to as a "distance golf club"). The presently disclosed 
golf club 26 includes a shaft 28 which includes a mid-section 30, a grip 
receiving portion 32 and a hosel mounting portion 34. The grip mounting 
portion 32 receives a grip. The hosel mounting portion 34 is mounted to 
the hosel 36 of a club head 38 of an iron (depicted) or a wood (not shown) 
via any suitable mounting technique known in the art. It is recognized 
that the club head 38 of a "wood" may be fabricated of wood, metal, a 
composite material, ceramic or any other hard suitable material, or 
combinations of such materials. The cross-section 40, in one embodiment, 
is generally oval or elliptical in shape. 
At least the mid-section 30 of the shaft 28 is provided with a non-circular 
cross section as illustrated in exemplary FIGS. 3A, 3B, 3C. In each case, 
the cross section of the mid-section of the shaft has a first dimension 
(w) in the direction of ball impact and a second dimension (l) in a 
direction transverse to ball impact and the second dimension is greater 
than the first dimension. FIG. 4A depicts one exemplary cross section for 
the mid-section 30 of the shaft 28 which is generally oval in shape, FIG. 
4B and 4C depict other exemplary cross sections for the mid-section 30 of 
the shaft 28 having a generally triangular shape. The shaft may be 
oriented so as to present a tapered leading edge (top of cross section as 
depicted in FIGS. 4A and 4B) for the mid-section 30 of the shaft 28 to 
minimize air resistance during the club swing and thus facilitate a 
greater club head velocity upon ball impact. 
Referring again to FIGS. 2 and 3, the grip receiving portion 32 may be 
provided with a generally circular cross section so as to be able to 
permit use of commercially available grips, or alternatively, the grip 
receiving portion 32 of the shaft 28 may have the cross section of the 
shaft 28 mid-section 30 or any other suitable cross section. In the event 
that the grip receiving portion 32 is provided with the same cross section 
as the mid-section 30, the golf club will require the use of a grip 36 
specially adapted to be disposed over the grip receiving portion 32 of the 
shaft 28. The grip receiving portion 32 of the shaft 28 may have cross 
section dimensions greater than upper portion of the shaft mid-section 30, 
substantially equal to the dimensions of the upper portion of the shaft 
mid-section 30, or smaller than the upper portion of the shaft mid-section 
30 (as depicted in FIG. 3. 
As illustrated in FIG. 5, the golf club 42 has a shaft 44 fabricated of a 
composite material such as a graphite composite and a club head 54. The 
shaft 44 has a central portion or mid-section 46, a grip receiving portion 
48 and a hosel mounting portion 50. At least the mid-section 46 of the 
shaft has a non-circular cross-section which is tapered from a mid-section 
region adjacent the grip receiving portion 48 to a mid-section region 
adjacent the hosel mounting portion 50. The hosel mounting portion 50 of 
the shaft 44 is mounted to the hosel 52 of the club head 54 via any 
conventional mounting technique. Such tapering of the mid-section provides 
for greater flex of the shaft 44 near the club head 54. 
In another embodiment illustrated in FIG. 6, the golf club 56 has a shaft 
58 fabricated of tubular steel. The shaft has a mid-section 60, a grip 
receiving portion 62 and a hosel mounting portion 64 and at least the 
mid-section 60 has a non-circular cross-section which is step tapered from 
a mid-section 60 region adjacent the grip receiving portion 62 to a 
mid-section 60 region adjacent the hosel mounting portion 64. The 
mid-section 60 of the shaft 58 is tapered in steps to provide greater flex 
of the shaft in the portion of the mid-section 60 adjacent the hosel 
mounting portion 64 as discussed hereinabove in conjunction FIG. 5. 
Referring to FIGS. 7 and 8, the shaft may be retrieved in one or more areas 
of the shaft mid-section as illustrated at 66 to obtain specific flex 
characteristics for the shaft. 
Finally, a putter is illustrated in FIG. 9. The putter has a shaft 68 which 
has a grip receiving portion 70, a central portion or mid-section 72 and a 
hosel mounting portion 74. The hosel mounting portion 74 is securely 
mounted to the hosel 76 of a putter head 78. The central portion is 
non-circular with a cross section such as illustrated in purely exemplary 
FIG. 9a in which the longest cross section dimension (in the direction of 
ball impact (l)) is greater than the widest cross section dimension (in 
the direction transverse to the direction of ball impact (w)). The central 
portion 72 of the shaft 68 may be tapered from a region adjacent the grip 
receiving portion 70 to a region adjacent the hosel mounting portion 74. 
Orientation of the shaft in the presently described orientation provides 
considerable shaft stiffness in the direction of ball impact while 
providing a shaft which can be fabricated of a light composite material 
such as a graphite composite. 
It will be evident that those skilled in the art, once given the benefit of 
the foregoing disclosure, may make numerous other uses and modifications 
of, and departures from the specific embodiments described herein without 
departing from the inventive concepts. Consequently, the invention is to 
be construed as embracing each and every novel feature and novel 
combination of features present in, or possessed by, the apparatus and 
techniques herein disclosed and limited solely be the scope and spirit of 
the appended claims.