Adjustably tensioned snap-release joint for an exercise golf club

An adjustably tensioned snap-release joint for use as a golf club swing training device is described which includes an upper shaft insert, a lower shaft insert, a screw inserted into a first bore in the lower shaft insert and inserted into a correspondingly threaded second bore in the upper shaft insert, the screw defining a rotation axis of the lower shaft member in relation to the upper shaft member to a transverse axis from a longitudinal axis defined by a linear alignment of the upper and lower shaft inserts in the golf club, an indentation positioned in a co-linear axis with the longitudinal axis of the golf club on an interior surface of the upper shaft insert, and an adjustable spring-biased hollow screw assembly having a ball positioned at the tip of a threaded shaft, capable of exerting pressure on the indentation.

TECHNICAL FIELD 
This invention relates to an adjustably tensioned snap-release joint for 
use in an exercise golf club. In particular, the device described is 
particularly applicable for use as a training device by a user in 
developing his golf swing in a manner which will facilitate the proper 
contact between a golf ball and the club face. 
BACKGROUND OF THE INVENTION 
The sport of golf is an activity which enjoys widespread popularity. The 
skill level of its participants range from the highly skilled professional 
to the weekend "duffer". However, it is recognized that no matter what the 
skill level, there are at least two parameters which will assist any 
golfer in maximizing the potential for the golfer to hit the straightest 
shot that he is capable of, (1) clean golf club faces; and (2) proper 
swing and resulting contact of the club face with the golf ball. 
Unlike many sports, avid golfers actively engage the game under adverse 
conditions. The potential for acquiring a build-up of grass and soil on 
the golf club face is quite significant, even under perfect conditions. 
There are a variety of cleaning devices and techniques which permit a 
golfer to resolve the first problem: (1) using a towel or other such 
cleaning material; (2) using the tee to remove debris from the grooves 
which are in the golf club face; and (3) using a brush to additionally 
clean the club face. It is the grooves in the club face which enable a 
golfer to accurately control the shot. When these grooves are filled in 
with debris, the control is thereby significantly diminished, leading to 
frustrating rounds of golf. 
Much more difficult to control is the golf swing itself. Without constant 
professional supervision, any golfer, no matter the skill level, will 
experience times when the golf swing does not produce the desired results. 
This is manifested in an abundance of hooks or slices or combinations 
thereof, as the golfer attempts to make subtle changes in his swing. 
Without the eye of a trained professional, it is not usually possible for 
the golfer to determine which component of his swing is causing the 
undesired result. 
Any golf swing has several stages which could be at less-than-optimal 
positions. The backswing, the peak at which maximum torque is achieved, 
the forward swing, the wrist snap at moment of contact, etc. At all phases 
of the swing, it is critical that the club head be in a specified zone 
with respect to the positioning of the hands. Improper positioning will 
lead to errant shots and frustrating rounds of golf. 
Previous attempts to aid a golfer in "grooving" his swing have included 
those such as described in U.S. Pat. No. 4,854,585 to Koch et al. In this 
assembly, a hinge mechanism is described which is interposed between the 
grip and the club head. The hinge mechanism includes a female member 
having first and second yoke portions defining a cavity permitting two-way 
movement of a male member between the yoke portions. An adjusting screw 
cooperates with a biasing spring and generally spherical member to adjust 
the force necessary to break or articulate the hinge mechanism. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, there is provided a simplified 
adjustably tensioned snap-release joint for use in an exercise golf club. 
In particular, it is an object of this invention to detail a training 
device applicable for use as a training device by a user in developing his 
golf swing in a manner which will facilitate the proper contact between a 
golf ball and the club face. 
It is a second object of this invention to provide an apparatus which will 
enable a golfer to self-analyze his swing characteristics in order to 
determine at which point in the swing, there is an improper positioning of 
the hands vis-a-vis the club head. 
It is a third object of this invention to provide an apparatus which will 
enable a golfer to adjust the tension required for the snap-release joint 
to shift out of alignment, thereby permitting the detection of not only 
gross swing flaws, but also much more subtle ones, and the entire range of 
defects therein. 
These and other objects of this invention will be evident when viewed in 
light of the drawings, detailed description, and appended claims.

DETAILED COMPONENT T LIST 
______________________________________ 
Part Number 
Description 
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2 upper shaft insert 
4 lower shaft insert 
6 grooved ridges on the upper shaft insert 
8 grooved ridges on the lower shaft insert 
10 pivot screw head 
12 pivot screw threads 
14 adjustably tensioned threaded screw bore 
16 non-beveled interior impinging surface for the 
tensioned screw 
18 exterior semicircular surface of the lower shaft 
insert 
20 exterior semicircular surface of the upper shaft 
insert 
22 beveled interior surface of the upper shaft insert 
24 pivot screw 
26 pivot screw shaft 
28 pivot screw turning means 
30 pivot screw head height 
32 adjustably tensioned screw 
34 washer 
36 washer bore 
38 oblique interior surface 
40 curvilinear peripheral edge of the upper shaft 
insert 
42 threaded pivot screw receiving bore 
44 circular raised segment of the upper shaft insert 
46 recessed pivot screw head bore 
48 pivot screw shaft bore 
50 circular raised segment of the lower shaft insert 
52 planar interior surface of the upper shaft insert 
54 curvilinear peripheral edge of the lower shaft 
insert 
56 planar interior face of the lower shaft insert 
58 retaining means for the spring inside the adjustably 
tensioned screw 
60 adjustably tensioned screw head 
62 adjustably tensioned screw threads 
64 ball 
66 biasing spring 
68 positioning means 
100 adjustably tensioned snap-release joint 
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DETAILED DESCRIPTION OF THE INVENTION 
Referring now to the drawings wherein the showings are for purposes of 
illustrating the preferred embodiment of the invention only and not for 
purposes of limiting the same, the Figures essentially show a user 
adjustably tensioned snap-release joint for use in an exercise golf club. 
More particularly, as shown in FIG. 1, the adjustably tensioned 
snap-release joint 100 is essentially fabricated from two mating parts. 
Upper shaft insert 2 is adapted for insertion into the handle portion of 
the shaft of a golf club, and lower shaft insert 4 is adapted for 
insertion into the club-face portion of the shaft of a golf club which has 
been suitably modified at the insertion points. The insertion and 
subsequent attachment is facilitated by the existence of grooved ridges 
6,8 positioned at the extremities of upper shaft insert 2 and lower shaft 
insert 4 respectively. It is recognized that the alignment of adjustably 
tensioned snap-release joint 100 is such that the plane defined by the 
rotation of upper shaft insert 2 and lower shaft insert 4 is coexistent 
with the plane of the golfer's swing as defined when the golfer is 
addressing the ball. 
As illustrated more clearly in FIG. 2, upper shaft insert 2 and lower shaft 
insert 4 are pivotally attached by a pivot screw 24. As shown in FIG. 5, 
pivot screw 24 is comprised of several component parts. Pivot screw head 
10 is mounted on pivot screw shaft 26 upon which pivot screw threads 12 
have been cut. In a preferred embodiment, pivot screw 24 is recessed into 
recessed pivot screw head bore 46 illustrated in FIG. 11. It is recognized 
that the depth of recessed pivot screw head bore 46 closely approximates 
the pivot screw head height 30. In order to facilitate the smooth pivoting 
function of pivot screw 24, washer 34 is inserted onto pivot screw shaft 
26 through washer bore 36 and positioned between upper shaft insert 2 and 
lower shaft insert 4. In a preferred embodiment, this washer is polymeric 
in nature. In a most preferred embodiment, the washer is teflon. The 
joining of the upper shaft insert 2 with club-face member 4 is effected by 
pivot screw threads 12 matingly engaging threaded pivot screw shaft bore 
42. In the preferred embodiment, since pivot screw 24 is recessed, pivot 
screw turning means 28 is provided at the top of pivot screw head 24. In 
one aspect of this invention, the turning means is by that such as an 
allen wrench. However, closed geometric polygons shapes, such as three, 
four, five, etc., are also envisioned. However, it is readily seen that 
the invention is not limited to such turning means. Conventional turning 
means, such as flat-head screwdriver slots and Phillips head screwdriver 
crossed slots are anticipated in addition to other turning means known in 
the art. 
As viewed in operation in FIG. 3, both upper shaft insert 2 and lower shaft 
insert 4 must have curvilinear peripheral edges 40 and 54 respectively, 
for the adjustably tensioned snap-release joint to operate. 
As viewed in greater detail in FIGS. 7 and 8, upper shaft insert 2 has 
several distinguishing features. Upper shaft insert includes exterior 
semicircular surface 20 through which threaded pivot screw receiving bore 
is positioned therethrough, curvilinear peripheral edge 40, circular 
raised segment 44, and planar interior surface 52. Key to the operation of 
adjustably tensioned snap-release joint 100 is the combination of 
non-beveled interior impinging surface 16 for the tensioned screw 52, 
beveled interior surface 22 and positioning means 68. In the machining of 
beveled surface 22, a pair of oblique surfaces 38 are created in upper 
shaft insert 2. As seen in the figure, non-beveled interior impinging 
surface 16 is essentially coplanar with planar interior surface 52. 
As shown specifically in FIG. 9, positioning means 68 may be a groove. 
However, it is contemplated that positioning means may be any surface 
indentation which would tend to retain adjustably tensioned screw 32 in 
its indentation. Specifically, it is envisioned that positioning means 68 
could be a hole. 
FIG. 10 depicts lower shaft insert 4 in greater detail. Specifically, lower 
shaft insert 4 includes exterior semicircular surface 18, through which 
adjustably tensioned threaded screw bore 14 and recessed pivot screw head 
bore 46 in combination with pivot screw shaft bore 48 extend therethrough, 
curvilinear peripheral edge 54 and planar interior face 56. Pivot screw 24 
is positioned in the combination of recessed pivot screw head bore 46 and 
pivot screw shaft bore 48. Adjustably tensioned screw 32 is positioned 
into adjustably tensioned threaded bore 14. 
The assembly of adjustably tensioned screw 32 is shown in FIGS. 12 and 13. 
Adjustably tensioned screw 32 includes adjustably tensioned screw head 60, 
screw threads 62, ball 64 which is peripherally biased by biasing means 66 
located on the interior of screw threads 62. Ball 64 is maintained within 
the confines of the interior region of adjustably tensioned screw 32 by 
the existence of retaining means 58 at the lower extremity of the screw. 
Placement of adjustably tensioned snap-release joint 100 into a golf club 
is determined by the location of the center of mass of the club. To 
determine such placement, the club is positioned on a fulcrum and the 
proper location is determined when the club remains balanced on the 
fulcrum with neither extremity of the club moving in a vertical direction. 
When the club is positioned in this manner, the attachment point for the 
adjustably tensioned snap-release joint 100 has been determined. Since the 
club face for an iron, or a club head for a wood, is typically of greater 
mass and weight than the grip, the snap-release joint will typically be 
positioned more closely to the club head or face than the grip. 
Alternative methods known in the art for determining the exact placement 
of the snap-release joint are envisioned. 
The material of construction used in the adjustably tensioned snap-release 
joint, except where specifically indicated, is typically steel. In a 
preferred embodiment, a stainless steel is employed. 
Discussion 
Many faulty golf swings are the result of improper positioning of the hands 
vis-a-vis the golf club head. The average golfer often tries to correct 
such swing defects by the utilization of swing adjustments which typically 
result in a jerky, or non-smooth at best, swing. Many times the golfer is 
unaware of these subtle corrections in his swing as they become an almost 
subconscious action. 
By using the adjustably tensioned snap-release joint in proper position in 
a golf club, the swing of a golfer can be self-analyzed by simply noting 
the position of the swing where the snap-release joint moves out of its 
normal linear alignment. For those golfers with very jerky swings, the 
adjustably tensioned screw may need to be positioned to generate a large 
degree of tension in order to be able to identify the most serious swing 
defects initially. By tightening the tensioning screw, additional pressure 
is applied to the upper shaft member through the shortened length imposed 
on the biasing spring thereby causing it to compress and generate 
additional force on the ball which impinges the upper shaft member of the 
snap-release joint. 
As the major problems disappear, then tension on the tensioning spring can 
be gradually relaxed, thereby effecting a proportionate decrease in the 
amount of generated force applied to the upper shaft insert, and more 
minor swing defects can be detected and corrected. 
One of the key features of the adjustably tensioned snap-release joint is 
the combination of a beveled surface in combination with a positioning 
means. Unlike previous devices, once the critical torque has been exerted 
which overcomes the tension generated by the tensioned screw, the beveled 
surface acts to accentuate the rotation action of the lower shaft insert 
in relation to the upper shaft insert. It is this cooperative interaction 
which aids in pinpointing the exact positioning of the swing flaw. 
As is known from basic physical principles, the shaft acts as a lever arm 
and forces imparted through the hands are coupled with the shaft length to 
exert a moment or torque about the adjustably tensioned snap-release 
joint. When the generated torque exceeds the pressure applied to the upper 
shaft insert, the snap-release joint will move out of its co-linear 
alignment and the golfer is alerted instantly to the location of the 
position in the swing which has produced the undesirable result. The 
ability to adjust this trigger point pressure is key to detecting a series 
of flaws in the golf swing ranging from serious to minor. 
The invention has been described with reference to the preferred 
embodiment. Obviously modifications and alterations will occur to others 
upon a reading and understanding of the specification. It is intended to 
include all such modifications and alterations insofar as they come within 
the scope of the appended claims or the equivalents thereof.