U.S. patent application number 10/433837 was filed with the patent office on 2004-02-26 for golf club.
Invention is credited to Ahlqvist, Stein G..
Application Number | 20040038745 10/433837 |
Document ID | / |
Family ID | 20282198 |
Filed Date | 2004-02-26 |
United States Patent
Application |
20040038745 |
Kind Code |
A1 |
Ahlqvist, Stein G. |
February 26, 2004 |
Golf club
Abstract
The invention relates to a golf club (1) comprising a shaft (3)
provided with a handle portion (2) and a club blade (5) projecting
from the lower portion (4) of said shaft (3), the hitting surface
(6) of said blade is provided with a plurality of scores or grooves
(7). Those grooves (7) are arranged at a predetermined mutual
distance and do extend in a diverging or parallel pattern or area
over at least the hitting surface (6) of the club blade (5).
Inventors: |
Ahlqvist, Stein G.;
(Lidingo, SE) |
Correspondence
Address: |
DICKSTEIN SHAPIRO MORIN & OSHINSKY LLP
2101 L STREET NW
WASHINGTON
DC
20037-1526
US
|
Family ID: |
20282198 |
Appl. No.: |
10/433837 |
Filed: |
June 9, 2003 |
PCT Filed: |
December 10, 2001 |
PCT NO: |
PCT/SE01/02727 |
Current U.S.
Class: |
473/331 |
Current CPC
Class: |
A63B 53/0445 20200801;
A63B 53/047 20130101; A63B 60/00 20151001; A63B 53/04 20130101 |
Class at
Publication: |
473/331 |
International
Class: |
A63B 053/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 12, 2000 |
SE |
0004592-2 |
Claims
1. A golf club comprising a shaft (3) provided with a handle
portion (2) and a club blade (5) projecting from its lower portion
(4) and, on the hitting surface (6) of the blade (5), a plurality
of scores or grooves (7), which are located at a predetermined
distance from each other and over at least the hitting surface (6)
of the club blade (5) are arranged in a diverging or parallel
pattern, characterized in that said grooves (7) on the hitting
surface (6) of the club blade (5) are at different mutual
distances, as counted from the blade bottom to its top or from its
toe (8) to its heel (9), or in the opposite direction, and do at
the same time diverge from the toe (8) towards the heel (9) or from
the bottom towards the top.
2. A golf club as claimed in claim 1, characterized in that said
grooves (7) are arranged at a smaller mutual distance at the bottom
than at the top of the club blade (5).
3. A golf club as claimed in claim 1, characterized in that the
distances between said grooves (7) are selected so as to match the
wanted backspin effect.
4. A golf club as claimed in claim 1, characterized in that the
distances between said grooves (7) vary in relation to the distance
from the centre of a club blade (5) towards the grooves (7).
5. A golf club as claimed in claim 1, characterized in that said
grooves (7) are diverging and also arranged over the hitting
surface (6) of the club blade (5) at varying mutual distances.
6. A golf club as claimed in claim 1, characterized in that the
extension of each groove (7) over the hitting surface (6) of the
club blade (5) is displaced relatively an adjacent groove (7).
7. A golf club as claimed in claim 1, characterized in that said
grooves (7) extend continously and/or discontinously over the
hitting surface (6) of the club blade (5).
Description
[0001] The present invention relates to a golf club which comprises
a shaft, provided with a handle portion, and a club blade
projecting from the lower portion of the shaft, a plurality of
depressions or grooves extending across the hitting surface of the
blade.
[0002] The golf clubs which today are available in the market do,
practially all of them, on the hitting surface on the club blade
exhibit some form of patterns or grooves, the primary purpose of
which is to increase the friction and accordingly also inter alia
the ball backspin generated in the hitting moment between the club
blade and the golf ball. In those cases when a golf ball is hit
exactly in the correct point on a standard club blade and with a
correct force, which can never be guaranteed, the golf ball travels
to the intended spot and the player can use any standard club to
reach a completely satisfactory result. If, however, when a
conventional standard club hits the ball above the ideal hit point
the ball will travel a shorter distance than intended due to the
fact that this portion of the blade moves slower than the central
point because in that case the radius of the rotation circle of the
club blade is shorter. The opposite will occur when the ball hits a
standard blade at its lower part meaning that in this case the ball
will travel farther than desired because the radius of the
rotational circle of the club blade will be greater. The difference
in terms of speed between the upper and the lower point on the
blade amounts to a number of significant percent values.. In
addition thereto attention has to be paid to the fact that when a
stroke is made and the lower portion of the blade hits the ball the
blade will move at the higher speed, also due to the fact that in
this case the blade cuts less or not at all down in the ground.
When this occurs there will be generated a certain resistance which
reduces the speed. On the other hand, if the upper portion of the
blade hits the ball, the soil will always present a resistance
because the blade does then dig itself deeper down than ideal.
Irrespective of how the club blade hits the ball the latter is all
the time at the same distance from the solid support layer. The
perfect stroke, a so called "square hit" does not exist in reality
because the movement of the golf player's hips is slower than the
club blade movement through the air. Consequently, a club blade
moves almost exactly along the periferi of its rotational circle in
response to a stroke and, for this reason, the ball travelling
distance will be different in response to the location of the golf
ball hitting point on a standard blade.
[0003] The object of the present invention is to provide a golf
club of the type mentioned above which comprises a club blade
having grooves on its hitting surface, said grooves being oriented
in such a way that the problems existing in the prior art golf club
have been eliminated. The characteristic features of the invention
are set out in the patent claims.
[0004] Thanks to the invention there has now been provided a golf
club which in an excellent manner satisfies the demands and, in
addition thereto, can be manufactured in a convenient way.
Accordingly, as distinct from the golf clubs of today, a club
according to the present invention offers a automatic compensation
of "bad" hits. Stated in other words, the ball will always stop in
desired positions irrespective of whether it has been hit at a high
or a low level, at the toe which moves quicker than the heel or at
the heel or in some other spot. This result is achieved thanks to
the fact that the grooves are arranged at a predetermined distance
between themselves so that they generate different friction forces
and/or in the way that the grooves exhibit a diverging or parallel
extension over at least the hitting surface of the club blade. It
is also possible, by variation of the spacing between the grooves,
when the stroke is made to create different "backspins". The design
of the blade according to the invention does also involve that that
irrespective of the ball hitting point on the blade the trajectory
of the ball will always be correct including its movement through
the air and its rolling along the ground until it has stopped.
Stated in other words, a long air passage yields a large backspin
effect and a short air passage yields a small backspin effect. The
final result is that the ball will always stop in the correct
position, the desired distance which could be expected from a
certain club.
[0005] Some preferred embodiments of the invention will now be
described, reference being made to the drawing.
[0006] FIG. 1 illustrates a club blade having diverging grooves
running from the toe to the heel of the club blade,
[0007] FIG. 2 shows a club blade having diverging grooves which are
displaced in respect of their relative positions as extending over
the hitting surface of the club blade,
[0008] FIG. 3 shows an alternative embodiment illustrating a club
blade at which the grooves are diverging and located in the hitting
surface of the blade, the distance between them being smaller lower
down than higher up. The grooves diverge from the toe towards the
heel,
[0009] FIG. 4 shows a club blade having parallel grooves with an
interdistance between them which is smaller at the lower portion of
the hitting surface than at the upper portion,
[0010] FIG. 5 does diagrammatically illustrate the rotation circle
of a club blade upon the stroke and different hitting points on the
blade at different radii,
[0011] FIG. 6 is a diagrammatical view showing different travelling
distances of a golf ball in response to which portion of the blade
that hits the ball and to how the ball moves on the ground after
the stroke which in the second case is somewhat stronger than in
the first case,
[0012] FIG. 7 does diagrammatically illustrate the type of back
backspin rotation performed by a ball when a club blade according
to the invention is used and in response to the hitting position on
the blade and the lateral spreading determined by whether the hit
takes place high up or lower down on the blade,
[0013] FIG. 8 does diagrammatically show different ball travelling
distances, where a) refers to a perfect stroke--perfect speed, b)
too high speed with a hitting position low down on the blade and
intensive backspin, and c) low speed--hitting position high up on
the blade--small backspin.
[0014] As appears from the drawings they do show a golf club 1
comprising a shaft 3 provided with a handle portion 2 and a club
blade 5 projecting from the lower portion 4 of shaft 3. Extending
over the hitting surface 6 is a plurality of depressions or grooves
7 located at predetermined interspacings and exhibiting a diverging
or parallel pattern over the surface 6 of club blade 5. The width
and the cross-sectional profile of grooves 7 are the same in all
the embodiments illustrated, along all of the hitting surface 6 and
also in the longitudinal direction of grooves 7. According to the
invention the hitting surface 6 of club blade 5 may exhibit a
plurality of grooves 7, the distances between them being different
at the foot and at the top of the blade 5 of club 1. The grooves 7
can diverge in one direction from the toe 8 of the club blade 5 to
the heel 9 of the club blade 5. Alternatively, grooves 7 may extend
from the heel 9 towards the toe 8 or at other imaginable angles.
Grooves 7 may also as an alternative diverge from the foot to the
top or the other way around. Stated in other words grooves 7 may
converge and/or diverge at all imaginable angles and directions.
FIG. 2 illustrates combinations of various grooves 7 positioned in
other patterns than those mentioned above, the grooves being
displaced relatively each other in their diverging longitudinal
direction.
[0015] Another alternative embodiment has been shown in FIG. 3
where the grooves 7 diverge from the toe 8 towards the heel 9, the
grooves 7 also being closer to each other at the foot than at the
top of club blade 5.
[0016] Thanks to the positioning according to the invention of the
grooves 7 with different distances between them at the foot and at
the top, as shown in FIGS. 3 and 4, there has been created a
possibility to vary the backspin in response to whether a golf ball
10 hits at the top or at the foot. Different backspins means that
the ball 10 will roll, or tends to roll, different distances
backwards on the ground with which it comes into contact following
its passage through the air. An arrangement of grooves 7 closer to
each other on the club blade 5 creates more backspin and,
accordingly, ball 10 will pass somewhat too long through the air
after having been hit by the lower portion 11 of blade 5 performing
a quicker movement than the upper portion 12 and, as shown for
example in FIG. 5, still travel a approximately correct distance
and, when the grooves 7 are less close to each other less backspin
will be generated meaning that the ball 10 also in that case
travels the correct distance. Consequently, thanks to the invention
one can compensate the stroke distance to a correct value,
corresponding to that the ball 10 is hit by the centre portion 13
irrespective of whether it does actually hit the top or the foot of
blade 5. The same function is achieved disregarding whether ball 10
hits the toe 8 of blade 5 or its heel 9. Contact at the toe 8 gives
the ball 10 a higher spin than at heel 9, meaning that the grooves
7 should then be located closer at the toe 8 than at the heel 9
resulting in that a hit at the toe 8 causes more backspin than a
hit at heel 9. The divergence of grooves 7 at the heel 9
compensates the total length of the movement including the air
travel and the ground rolling irrespective of whether ball 10 is
hit by blade 5 at the toe 8 thereof or at the heel 9, the wanted
correct distance being always achieved.
[0017] Consequently, as has been mentioned above, the contact point
on the club blade 5 with the ball 10 will always yield a correct
travelling distance of ball 10 up to the moment when it is lying
still on the ground after having finished its air travel and the
rolling.
[0018] In the case when the club blade 5 hits the ball 10 to high
it does actually do so to late. The result of this will be that the
ball 10 will deviate to the left for a right-handed player and to
the right for a left-handed player. If the ball 10 hits the blade 5
too low this means at the blade 5 hits the ball 10 too early and
the ball 10 will then in a logical manner deviate to the right if
the player is right-handed. The explanation of this becomes obvious
if one, for each of the different hitting points, places any
imagined vertical plane at the right angles to the stroke
direction. When the ball 10 is hit by the centre of blade 5 the
direction will be correct but all other hitting points will cause a
greater or smaller incorrect direction. The spread in the lateral
direction can amount to as much as 7-8 metres after an air travel
with our without a rolling distance, for example 175 m. The
characteristic feature of the invention, diverging grooves 7, means
that the backspin rotation of ball 10 will vary in response to the
actual hitting point of ball 10 on club blade 5. This has been
illustrated more in detail in FIGS. 5 and 6. A hitting point at the
centre of blade 5, which also is the ideal point, yields a
"straight" backspin. If the ball 10 is hit by the blade 5 to high
up, the result will, due to the presence of the diverging grooves
7, become a screwed backspin causing the ball 10 to rotate to the
right. Since, at a hit too high up, the vertical plane mentioned
above causes the ball 10 in a normal manner to deviate to the left
and the ball 10 now is in a rotation movement to the right, those
two parametres will cancel each other and, finally, the ball 10
will stop at the wanted spot, namely correctly in the desired
stroke direction. Conversely, if the ball 10 is hit by the blade 5
too low, it will be given it a backspin directed to the left. This
does in its turn compensate away the lateral error which otherwise
would have caused the ball 10 to travel too far to the right. It
can consequently be said that irrespective of where on the blade 5
it contacts the ball 10 the diverging or parallel grooves 7 will
compensate away all erroneous hits and the ball 10 will always
reach the wanted spot. Moreover, after its air travel ball 10 will
roll on the ground in its screwed backspin to the right or to the
left, respectively, and still more compensate a lateral error so
that the ball 10, when eventually resting still on the ground, will
be found in the wanted position.
[0019] Accordingly, the final result will be that thanks to the
concept according to the invention the ball 10 will reach the
correct spot in both the longitudinal and the lateral direction and
this irrespective of whether the club hits the ball 10 correctly,
to the left, to the right, at the top or at the foot, too early or
too late. This is not the case at the golf clubs today available in
the market. The old concept, featuring parallel grooves with the
same spacing, does accordingly not offer any compensation for bad
hits be it in the longitudinal or in the lateral direction. The
final position of a ball after its air travel and the rolling on
the ground can thus be controlled both longitudinally and laterally
in an optimal way when a golf club according to the invention is in
use.
* * * * *