U.S. patent application number 17/098401 was filed with the patent office on 2021-05-27 for golf swing training club.
The applicant listed for this patent is Herman PRESBY, Benjamin S. WALLACE. Invention is credited to Herman PRESBY, Benjamin S. WALLACE.
Application Number | 20210154550 17/098401 |
Document ID | / |
Family ID | 1000005388798 |
Filed Date | 2021-05-27 |
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United States Patent
Application |
20210154550 |
Kind Code |
A1 |
PRESBY; Herman ; et
al. |
May 27, 2021 |
GOLF SWING TRAINING CLUB
Abstract
A golf swing training club comprising: (a) a shaft; (b) a golf
head attached to a first, lower end of the shaft; and (c) a
handgrip attached to a second, upper end of the shaft; wherein a
standard longitudinal shaft bending angle (.beta.) of the shaft is
within a range of 45.degree. to 90.degree.; and wherein a
mechanical beam portion of the golf swing training club is
characterized by a standard extensive shear modulus of at most
15.degree..
Inventors: |
PRESBY; Herman; (Highland
Park, NJ) ; WALLACE; Benjamin S.; (Edison,
NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PRESBY; Herman
WALLACE; Benjamin S. |
Highland Park
Edison |
NJ
NJ |
US
US |
|
|
Family ID: |
1000005388798 |
Appl. No.: |
17/098401 |
Filed: |
November 15, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
16691223 |
Nov 21, 2019 |
10857443 |
|
|
17098401 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A63B 2209/00 20130101;
A63B 69/3685 20130101; A63B 69/3632 20130101; A63B 53/10
20130101 |
International
Class: |
A63B 69/36 20060101
A63B069/36; A63B 53/10 20060101 A63B053/10 |
Claims
1. A golf swing training club comprising: (a) a shaft; (b) a golf
head attached to a first, lower end of said shaft; and (c) a
handgrip attached to a second, upper end of said shaft; wherein a
portion of said shaft that is disposed between the handgrip and the
golf head includes a braided layer; wherein a standard longitudinal
shaft bending angle (.beta.) of said shaft is within a range of
45.degree. to 90.degree.; wherein a mechanical beam portion of the
golf swing training club, having a length of at least 18 inches, is
characterized by a standard extensive shear modulus of at most
15.degree.; and wherein said braided layer has a lazy tongs
structure.
2. The golf swing training club of claim 1, wherein said standard
longitudinal shaft bending angle (.beta.) of said shaft is at least
60.degree..
3. The golf swing training club of claim 1, wherein said standard
longitudinal shaft bending angle (.beta.) of said shaft is within a
range of 55.degree. to 90.degree..
4. The golf swing training club of claim 1, wherein said standard
longitudinal shaft bending angle (.beta.) of said shaft is within a
range of 60.degree. to 89.degree..
5. The golf swing training club of claim 1, wherein said braided
layer includes a braided layer of metal.
6. The golf swing training club of claim 4, wherein said braided
layer is a braided layer of metal.
7. The golf swing training club of claim 1, wherein disposed within
said braided layer is a tube having a flexural modulus of at most
0.05 GPa.
8. The golf swing training club of claim 1, wherein disposed within
said braided layer is a tube having a flexural modulus of at most
0.01 GPa.
9. The golf swing training club of claim 1, wherein said golf head
is a putting head.
10. The golf swing training club of claim 1, wherein said golf head
is a driving head.
11. The golf swing training club of claim 1, wherein said golf head
is an iron.
12. The golf swing training club of claim 1, wherein said standard
extensive shear modulus is within a range of 2.degree. to
15.degree..
13. The golf swing training club of claim 1, wherein said standard
extensive shear modulus is within a range of 3.degree. to
12.degree..
14. The golf swing training club of claim 12, wherein disposed
within said braided layer is a tube having a flexural modulus of at
most 0.01 GPa.
15. The golf swing training club of claim 1, wherein said standard
extensive shear modulus is within a range of 2.degree. to
15.degree., and wherein said standard longitudinal shaft bending
angle (.beta.) of said shaft is within a range of 60.degree. to
89.degree..
16. A golf swing training club comprising: (a) a shaft; (b) a golf
head attached to a first, lower end of said shaft; and (c) a
handgrip attached to a second, upper end of said shaft; wherein a
portion of said shaft that is disposed between the handgrip and the
golf head includes a braided layer; wherein a standard longitudinal
shaft bending angle (.beta.) of said shaft is within a range of
45.degree. to 90.degree.; and wherein a mechanical beam portion of
the golf swing training club, having a length of at least 18
inches, is characterized by a standard extensive shear modulus of
at most 15.degree..
17. The golf swing training club of claim 16, wherein said braided
layer is a braided layer of metal.
18. The golf swing training club of claim 16, wherein disposed
within said braided layer is a tube.
19. The golf swing training club of claim 16, wherein said standard
extensive shear modulus is within a range of 2.degree. to
15.degree..
20. The golf swing training club of claim 19, wherein said standard
longitudinal shaft bending angle (.beta.) of said shaft is within a
range of 60.degree. to 89.degree..
Description
FIELD AND BACKGROUND OF THE INVENTION
[0001] The present invention relates to a golf swing training club
for promoting a correct swing motion.
[0002] While many such training golf clubs exist, the present
inventors have found that many fail to improve the user's swing
motion, and in some cases, various known training golf clubs may
actually strengthen certain impediments in the user's swing motion.
Thus, the present inventors have recognized a need for improved
training golf clubs.
SUMMARY OF THE INVENTION
[0003] According to teachings of the present invention there is
provided a golf swing training club comprising: (a) a shaft; (b) a
golf head attached to a first, lower end of the shaft; and (c) a
handgrip attached to a second, upper end of the shaft; wherein a
standard longitudinal shaft bending angle (.beta.) of the shaft is
within a range of 45.degree. to 90.degree.; and wherein a
mechanical beam portion of the golf swing training club is
characterized by a standard extensive shear modulus (or standard
angular deflection) of at most 15.degree..
[0004] According to teachings of the present invention there is
provided a swing training club comprising: (a) a shaft; (b) a golf
head attached to a first, lower end of the shaft; and (c) a
handgrip attached to a second, upper end of the shaft; wherein a
portion of the shaft that is disposed between the handgrip and the
golf head includes a braided layer or braided hose having a lazy
tongs structure.
[0005] According to teachings of the present invention there is
provided a golf swing training club comprising: [0006] (a) a shaft
having a first, lower end, and a second, upper end; and [0007] (b)
a handgrip attached to, or adapted to attach to, a second, upper
end of said shaft; [0008] wherein said first, lower end of said
shaft is attached to, or is adapted to attach to, a golf head;
[0009] wherein, in an operative, assembled mode of the golf swing
training club, said handgrip is attached to said second, upper end
of said shaft, and said first, lower end of said shaft is attached
to said golf head; [0010] wherein, in said operative, assembled
mode, a standard longitudinal shaft bending angle (.beta.) of said
shaft is within a range of 45.degree. to 90.degree..
[0011] According to teachings of the present invention there is
provided a golf swing training club comprising: [0012] (a) a shaft;
[0013] (b) a golf head attached to a first, lower end of said
shaft; and [0014] (c) a handgrip attached to a second, upper end of
said shaft; [0015] wherein a portion of said shaft that is disposed
between the handgrip and the golf head includes a braided layer;
[0016] wherein a longitudinal shaft bending angle (.beta.) of said
shaft is within a range of 45.degree. to 90.degree.; [0017] .beta.
being defined as an angle that said shaft makes when said shaft is
held horizontally, using a golf head having a standard weight of
350 grams, with said shaft being supported in a hold position
solely on a side of said shaft that is proximal to said handgrip,
such that a length of a free beam between said hold position and
said putting head is 20 inches; [0018] wherein a downward bend
(L.sub.dip) from horizontal and a resultant horizontal extension
(L.sub.hor) are measured in inches; [0019] and wherein .beta. is
calculated according to:
[0019] .beta.=tan.sup.-1 (L.sub.dip/L.sub.hor);
and wherein a standard extensive shear modulus is determined by a
shaft torque measuring machine having a torsion control head having
a cradle adapted to receive said shaft, said torsion control head
having a torsion arm adapted to receive a torsion weight so as to
exert a predetermined load of 1 pound/foot; [0020] and wherein a
mechanical beam portion of the golf swing training club is
characterized by said standard extensive shear modulus being at
most 15.degree..
[0021] According to further features in the described preferred
embodiments, a portion of said shaft that is disposed between the
handgrip and the golf head includes a braided layer.
[0022] According to still further features in the described
preferred embodiments, the braided layer has a lazy tongs
structure.
[0023] According to still further features in the described
preferred embodiments, the golf swing training club includes the
golf head, the golf head being attached to, or reversibly attached
to, said first, lower end of said shaft.
[0024] According to still further features in the described
preferred embodiments, the standard longitudinal shaft bending
angle (.beta.) of said shaft is at least 70.degree..
[0025] According to still further features in the described
preferred embodiments, the standard longitudinal shaft bending
angle (.beta.) of said shaft is within a range of 75.degree. to
89.degree..
[0026] According to still further features in the described
preferred embodiments, the braided layer or braided hose is or
includes a metal braided layer or metal braided hose.
[0027] According to still further features in the described
preferred embodiments, the golf swing training club comprises a
tube disposed underneath the braided layer or braided hose.
[0028] According to still further features in the described
preferred embodiments, the tube has a flexural modulus of at most
0.05 GPa, at most 0.03 GPa, at most 0.01 GPa, at most 0.005 GPa, or
at most 0.002 GPa.
[0029] According to still further features in the described
preferred embodiments, the golf head is reversibly detachable from
said shaft.
[0030] According to still further features in the described
preferred embodiments, the golf head and the first end of the shaft
have complementary threading, whereby the golf head is reversibly
detachable from said shaft.
[0031] According to still further features in the described
preferred embodiments, the golf head is a putting head.
[0032] According to still further features in the described
preferred embodiments, the golf head is a driving head.
[0033] According to still further features in the described
preferred embodiments, the golf head is an iron.
[0034] According to still further features in the described
preferred embodiments, the standard longitudinal shaft bending
angle (.beta.) of the shaft is at least 50.degree., at least
60.degree., at least 70.degree., at least 80.degree., or at least
85.degree..
[0035] According to still further features in the described
preferred embodiments, the standard longitudinal shaft bending
angle (.beta.) of the shaft is within a range of 55.degree. to
90.degree., 65.degree. to 90.degree., 75.degree. to 90.degree.,
75.degree. to 89.degree., 75.degree. to 88.degree., 55.degree. to
85.degree., 65.degree. to 85.degree., or 75.degree. to
85.degree..
[0036] According to still further features in the described
preferred embodiments, the standard extensive shear modulus is at
most 12.degree., at most 10.degree., at most 8.degree., or at most
6.degree..
[0037] According to still further features in the described
preferred embodiments, the standard extensive shear modulus is at
least 2.degree..
[0038] According to still further features in the described
preferred embodiments, the standard extensive shear modulus is
within a range of 2.degree. to 15.degree., 2.degree. to 12.degree.,
2.degree. to 10.degree., 2.degree. to 8.degree., 3.degree. to
15.degree., 3.degree. to 12.degree., 3.degree. to 10.degree.,
3.degree. to 8.degree., 4.degree. to 12.degree., 4.degree. to
10.degree., 4.degree. to 8.degree., 5.degree. to 12.degree., or
5.degree. to 10.degree..
[0039] According to still further features in the described
preferred embodiments, the flexural modulus of the element is at
most 0.04 GPa, at most 0.03 GPa, at most 0.02 GPa, at most 0.01
GPa, at most 0.005 GPa, at most 0.004 GPa, at most 0.003 GPa, at
most 0.0025 GPa, at most 0.002 GPa, or at most 0.0015 GPa.
[0040] According to still further features in the described
preferred embodiments, the flexural modulus of the element is at
least 0.0001 GPa, and typically, within a range of 0.0001 to 0.04
GPa, 0.0001 to 0.01 GPa, 0.0001 to 0.005 GPa, 0.0001 to 0.003 GPa,
0.0001 to 0.002 GPa, 0.0002 to 0.005 GPa, 0.0005 to 0.005 GPa, or
0.0005 to 0.003 GPa.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] The invention is herein described, by way of example only,
with reference to the accompanying drawings. With specific
reference now to the drawings in detail, it is stressed that the
particulars shown are by way of example and for purposes of
illustrative discussion of the preferred embodiments of the present
invention only, and are presented in the cause of providing what is
believed to be the most useful and readily understood description
of the principles and conceptual aspects of the invention. In this
regard, no attempt is made to show structural details of the
invention in more detail than is necessary for a fundamental
understanding of the invention, the description taken with the
drawings making apparent to those skilled in the art how the
several forms of the invention may be embodied in practice.
Throughout the drawings, like-referenced characters are used to
designate like elements.
[0042] In the drawings:
[0043] FIG. 1 is a schematic side view of a training club embodying
the invention;
[0044] FIG. 2 is a side view of an actual embodiment of the
inventive training club provided in FIG. 1;
[0045] FIG. 3 is a side view of the inventive training club of FIG.
2, in which the inventive training club is in a curled-up
position;
[0046] FIG. 4 is a side view, at an enlarged scale, of a portion of
the shaft provided in FIG. 2;
[0047] FIG. 5 is a schematic perspective view of a braided metal
exterior for the shaft provided in FIG. 2, in accordance with an
embodiment of the present invention;
[0048] FIG. 6 is a side, partially cut-open view, at an enlarged
scale, of a portion of the shaft provided in FIG. 2, in which is
exposed an inner tube beneath the braided metal exterior; and
[0049] FIG. 7 is a rear view of the golf head provided in FIG. 2,
in which is revealed an attachment assembly attaching the shaft to
the golf head, in accordance with an embodiment of the present
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0050] The principles and operation of the golf swing training club
according to the present invention may be better understood with
reference to the drawings and the accompanying description.
[0051] Before explaining at least one embodiment of the invention
in detail, it is to be understood that the invention is not limited
in its application to the details of construction and the
arrangement of the components set forth in the following
description or illustrated in the drawings. The invention is
capable of other embodiments or of being practiced or carried out
in various ways. Also, it is to be understood that the phraseology
and terminology employed herein is for the purpose of description
and should not be regarded as limiting.
[0052] The present invention provides a dynamic training tool whose
repeated use will help a golfer to feel the proper golf swing, and
ultimately, to improve the golf swing when golfing using a regular
golf club.
[0053] The inventors have found that golfers can better learn the
feel of a proper swing by using a training club having a flexible,
substantially non-resilient shaft.
[0054] The inventors have further found that learning the feel of a
proper swing, without the follow-up step of proper striking of the
golf ball, may substantially mitigate the benefit derived from the
swing improvement. However, the inventors have found that by
compounding the structural feature of a flexible, substantially
non-resilient shaft with another structural feature--strong
resistance of the shaft to torque (i.e., about the shaft axis), the
efficacy of the golf swing training club is appreciably enhanced.
These structural features are embodied in the training club
described hereinbelow.
[0055] With reference now to the figures, FIG. 1 is a schematic
side view of a golf swing training club 100 embodying the
invention. Training club 100 includes a shaft 20 having a length
Ls, a golf head 40, having a length (along shaft 20) Lh, attached
to a first or lower end of shaft 20, and a handgrip 60 having a
length Lg, attached to a second or upper end of shaft 20. The shaft
may extend through at least a portion (and typically the entire
length) of handgrip 60. In this case, the shaft length is defined
so as to include the length of the shaft covered by the
handgrip.
[0056] During the swing, shaft 20 along with the portion of
handgrip 60 disposed beneath the hands, form a mechanical beam 21,
whose length is the unsupported length of the shaft along with the
length of the handgrip between the hands and the golf head.
[0057] In evaluating the mechanical properties of this beam, the
top 5 inches of the handgrip are considered to be for hand
placement, such that the beam length Lbeam is measured from below
this point, until 1.5 inches from the opposite end of the
shaft.
[0058] FIG. 2 is a side view of an actual embodiment of the
inventive training club provided in FIG. 1. In this exemplary
embodiment, shaft 20 includes a braided layer forming a hose or
tubular element.
[0059] The hose braiding for shaft 20 may be formed from steel or
stainless steel, such as austenitic stainless steels.
Titanium-stabilized stainless steels may be particularly suitable.
Typically, the stainless steel is cold-rolled stainless steel.
Other metals, notably bronze, may be used for the wires forming the
braids. In some embodiments, various stiff fibers, such as carbon
or aramid fibers, may be processed into hose braiding, or at least
a portion thereof.
[0060] Both regular or standard braiding and knurled braiding may
be suitable for forming the braided hose of the present invention.
In standard braiding, the wires on the wire clapper are disposed in
parallel to each other, while with knurled braiding, the individual
wires of the clapper are additionally braided with each other.
[0061] FIG. 3 is a side view of the inventive training club of FIG.
2, in which the inventive training club is in a curled-up position.
This curled-up position is fully reversible. Moreover, in assuming
this position, shaft 20 exhibits no appreciable resistance to
curling up.
[0062] FIG. 4 is a side view, at an enlarged scale, of a portion of
the shaft provided in FIG. 2, in which the braided metal (hose)
exterior 22 is better viewed.
[0063] FIG. 5 is a schematic perspective view of braided metal
exterior 22, for use in accordance with an embodiment of the
present invention. The braided structure may advantageously be
configured in a lazy tongs 25 structure or configuration having an
axially expanded position and an axially contracted position. The
expanded position may be attained by axial tension with the wires
having the smallest crossing angles. The crossing angle and
diameter increase to the largest value through axial contraction.
When fabricated in a golf club shaft, such a configuration may
exhibit excellent longitudinal flexibility, while maintaining good
torque resistance (low angular deflection of the shaft or
beam).
[0064] As used herein in the specification and in the claims
section that follows, the term "lazy tongs structure" and the like
refers to a structure such as a braided structure that attains such
an axially expanded position and an axially contracted position in
a repeatable and reversible fashion.
[0065] FIG. 6 is a side, partially cut-open view, at an enlarged
scale, of a portion of the shaft provided in FIG. 2, in which is
exposed an optional inner tube or layer 24 beneath the braided
metal exterior 22. Inner tube or layer 24 may be made of, or
include, flexible rubber or flexible plastic. Inner tube or layer
24 may be disposed along an entire length of the shaft, or along a
portion thereof.
[0066] FIG. 7 is a rear view of the golf head provided in FIG. 2,
in which is revealed an attachment assembly attaching the shaft to
the golf head, in accordance with an embodiment of the present
invention.
[0067] Typically, the golf head for use in conjunction with the
present invention has a standard head weight. The inventors have
found that in many instances, it may be deleterious to utilize a
golf head having a head weight that is above the standard head
weight.
[0068] Thus, in some embodiments, the golf head has a weight of at
most 400 grams, at most 380 grams, or at most 360 grams, and
typically, within a range of 200 to 400 grams, 250 to 400 grams,
250 to 380 grams, 300 to 400 grams, 320 to 400 grams, 330 to 400
grams, 330 to 380 grams, or 330 to 370 grams.
[0069] The diameter of the shaft of the invention may be close to
the diameter of a standard club which is about 0.5 in. The shaft
diameter may be within a range of 0.2 to 1 inches, 0.35 to 0.8
inches, 0.35 to 0.7 inches, 0.35 to 0.65 inches, 0.35 to 0.6
inches, 0.35 to 0.55 inches, 0.4 to 0.8 inches, 0.4 to 0.7 inches,
0.4 to 0.65 inches, 0.4 to 0.6 inches, or 0.4 to 0.55 inches.
[0070] The shaft length may be of any practical length, but is
typically within a range of 28 to 38 inches, 30 to 38 inches, 28 to
36 inches, 30 to 36 inches, or 32 to 36 inches.
[0071] The length of the total club may be of any practical length,
but is typically within a range of 28 to 40 inches, 28 to 38
inches, 30 to 38 inches, 28 to 36 inches, 30 to 36 inches, or 32 to
36 inches.
EXAMPLES
[0072] Reference is now made to the following examples, which
together with the above descriptions, illustrate the invention in a
non-limiting fashion.
Example 1
[0073] Measurement Procedure: Extensive Shear Modulus
[0074] Shear modulus as an extensive property for golf clubs can be
characterized by a shaft torque analyzer, e.g., an apparatus that
measures the angular deflection of the shaft under standard and
repeatable conditions. Commercially available apparatus for this
purpose include the Auditor.RTM. 050312 digital shaft torque
measuring machine.
[0075] Such shaft torque measuring machines are typically equipped
with a torsion control head having a cradle adapted to receive a
golf shaft. The torsion control head has a torsion arm, and may be
adapted to receive a torsion weight at a predetermined position
along the arm, so as to exert a predetermined load. In the
measurement procedure used herein, the predetermined load is 1
pound/foot. When properly inserted, the shaft should protrude past
the back (inwardly disposed) side of the torsion control head clamp
by 1.5 inches.
[0076] The shaft torque measuring machine includes a shaft butt
clamp, which is typically adapted to freely slide on a track having
length scale marks, and to be locked at any desired position along
the track. The shaft of the training golf club should protrude past
the front (inwardly disposed) side of the shaft butt clamp by 5
inches.
[0077] The "mechanical beam length" (L.sub.beam) is the unsupported
length of the shaft between the clamps, which is typically 6.5
inches less than the length of the total club, length ranges of
which are provided hereinabove.
[0078] As used herein in the specification and in the claims
section that follows, the term "mechanical beam" or "mechanical
beam portion" refers to a mechanical beam whose length ("mechanical
beam length") is at least 18 inches, as measured according to the
procedure delineated in Example 1. More typically, the mechanical
beam length is at least 20 inches or at least 22 inches, and yet
more typically, within a range of 18 to 34 inches, 18 to 32 inches,
20 to 34 inches, 20 to 32 inches, 22 to 34 inches, 22 to 32 inches,
22 to 30 inches, or 24 to 30 inches.
[0079] As used herein in the specification and in the claims
section that follows, the term "standard extensive shear modulus"
refers to the angular deflection of the mechanical beam, as
measured by the above-described digital shaft torque measuring
machine under the measuring conditions provided in Example 1 (or as
measured by a comparable measuring machine under the measuring
conditions provided in Example 1). This mechanical property is also
termed "standard angular deflection".
Example 2
[0080] Measurement: Extensive Shear Modulus
[0081] The standard extensive shear modulus (expressed as angular
deflection, in degrees) for various training golf clubs of the
present invention was found to be at most 15.degree.. More
typically, the angular deflection was at most 12.degree., or at
most 10.degree., at most 8.degree., or at most 6.degree.. The
angular deflection was at least 2.degree.. The angular deflection
was typically within a range of 2.degree. to 15.degree., 2.degree.
to 12.degree., 2.degree. to 10.degree., 2.degree. to 8.degree.,
3.degree. to 15, 2.degree., 3.degree. to 12.degree., 3.degree. to
10.degree., 3.degree. to 8.degree., 4.degree. to 12.degree.,
4.degree. to 10.degree., 4.degree. to 8.degree., 5.degree. to
12.degree., or 5.degree. to 10.degree..
[0082] Utilizing thicker wires for the braiding, utilizing stiffer
materials of construction, and utilizing more than one layer of
braiding all contribute to a reduction in the angular
deflection.
Example 3
[0083] Measurement Procedure: Extensive Bending
[0084] Extensive longitudinal (i.e., along the length of the shaft
axis) bending of the shaft may be characterized by the angle the
shaft makes when held horizontally, using a putting head of
standard weight--350 grams.
[0085] The shaft is held or supported solely on the handgrip side,
such that the length of the free beam between the hold position and
the putting head is 20 inches. The downward bend or vertical dip
("DIP LENGTH", or L.sub.dip) from horizontal is measured, in
inches, as is the resultant horizontal extension ("HORIZONTAL
LENGTH", or L.sub.hor). The standard shaft bending angle (in
degrees) may be calculated by the following formula:
standard longitudinal shaft bending angle (.beta.)=tan.sup.-1
(L.sub.dip/L.sub.hor)
[0086] Thus, for an idealized, non-bending shaft, L.sub.dip=0 and
L.sub.hor=20, such that the standard longitudinal shaft bending
angle (.beta.)=0.degree.. For an idealized, fully-bending shaft,
L.sub.dip=20 and L.sub.hor=0, such that the standard longitudinal
shaft bending angle (.beta.)=90.degree..
[0087] As used herein in the specification and in the claims
section that follows, the term "standard longitudinal shaft bending
angle", .beta., and the like, refers to the longitudinal bending
angle of the shaft, in degrees, measured according to this
procedure.
Example 4
[0088] Various standard golf clubs were tested using the extensive
bending procedure provided in Example 3. In all cases, the standard
longitudinal shaft bending angle (.beta.) was less than 1.degree.,
in some cases, considerably less than 1.degree..
Example 5
[0089] Various golf swing training clubs of the present invention
were evaluated using the extensive bending procedure provided in
Example 3. In most cases, the bending angle (.beta.) approached
90.degree., and in all cases, the standard longitudinal shaft
bending angle (.beta.) was within the range of 45.degree. to
90.degree..
Example 6
[0090] Measurement Procedure: Flexural Modulus
[0091] The flexural modulus for golf club shaft materials can be
characterized by various bending tests. While we have adopted the
general approach of ASTM D790, the skilled practitioner will
readily appreciate that other bending tests may be particularly
suitable. The skilled practitioner will also readily appreciate
that bend test applications are common in various industries, and
that universal testing machines equipped with bend fixtures are
known for measuring/calculating the flexural modulus.
[0092] The ASTM D790 approach utilizes three-point bend fixtures,
in which the specimen (in this case, the material of construction
of the shaft) is loaded at a location midway between two support
bearings. ASTM D790 is typically used to measure the flexural
strength and flexural modulus of unreinforced and reinforced
plastics, including high-modulus composites.
Example 7
[0093] Below is provided the flexural modulus of various materials
of construction for use as shaft materials (e.g., a tube for
disposing within the shaft), as characterized by ASTM D790.
TABLE-US-00001 POLYMER TYPE Flexural Modulus (GPa) Acetal Copolymer
2.5 Acrylic 3 Nylon 6 2.3 Polyamide-Imide 5 Polycarbonate 2.3
Polyethylene, MDPE 0.7 Polyethylene Terephthalate (PET) 1 Polyimide
3 Polyimide + Glass Fiber 12 Polypropylene 1.5 Polystyrene 2.5 PVC
- plasticized/unfilled 3 PVC -- foam grade 0.04 PVC -- plasticized
0.001 Rubber1 0.0007 Rubber2 0.003
[0094] In the context of the present application and claims, the
phrase "at least one of A and B" is equivalent to an inclusive
"or", and includes any one of "only A", "only B", or "A and B".
Similarly, the phrase "at least one of A, B, and C" is equivalent
to an inclusive "or", and includes any one of "only A", "only B",
"only C", "A and B", "A and C", "B and C", or "A and B and C".
[0095] As used herein in the specification and in the claims
section that follows, the terms "top", "bottom", "upper", "lower",
"height" and "side" and the like are utilized for convenience of
description or for relative orientation, and are not necessarily
intended to indicate an absolute orientation in space.
[0096] It will be appreciated that certain features of the
invention, which are, for clarity, described in the context of
separate embodiments, may also be provided in combination in a
single embodiment. Conversely, various features of the invention,
which are, for brevity, described in the context of a single
embodiment, may also be provided separately or in any suitable
sub-combination.
[0097] Although the invention has been described in conjunction
with specific embodiments thereof, it is evident that many
alternatives, modifications and variations will be apparent to
those skilled in the art. Accordingly, it is intended to embrace
all such alternatives, modifications and variations that fall
within the spirit and broad scope of the appended claims. All
publications, patents and patent applications mentioned in this
specification, including U.S. Pat. No. 5,026,063, are herein
incorporated in their entirety by reference into the specification,
to the same extent as if each individual publication, patent or
patent application was specifically and individually indicated to
be incorporated herein by reference. In addition, citation or
identification of any reference in this application shall not be
construed as an admission that such reference is available as prior
art to the present invention.
* * * * *