U.S. patent application number 12/259627 was filed with the patent office on 2009-05-14 for golf putting trainer.
This patent application is currently assigned to JAPANA CO., LTD.. Invention is credited to Hironobu Matsuura, Shinobu Midorikawa, Shinichiroh Taira.
Application Number | 20090124404 12/259627 |
Document ID | / |
Family ID | 38655296 |
Filed Date | 2009-05-14 |
United States Patent
Application |
20090124404 |
Kind Code |
A1 |
Taira; Shinichiroh ; et
al. |
May 14, 2009 |
GOLF PUTTING TRAINER
Abstract
Provided is a putting-training tool for enabling a user to train
the putting while realizing that the error of a ball hitting angle
may be confined within about 2 degrees. The putting-training tool
is characterized in that a golf ball rolling groove has a width of
9 mm to 5 mm and has a transverse section gently-recessed into a
curved face for supporting a golf ball at one point, so that the
golf ball may not leave, in case a putting force to roll the golf
ball by about 1.5 m to 2 m on the green is applied, the golf ball
rolling groove for errors of the ball hitting angle less than 2
degrees.
Inventors: |
Taira; Shinichiroh; (Aichi,
JP) ; Midorikawa; Shinobu; (Aichi, JP) ;
Matsuura; Hironobu; (Aichi, JP) |
Correspondence
Address: |
CANTOR COLBURN, LLP
20 Church Street, 22nd Floor
Hartford
CT
06103
US
|
Assignee: |
JAPANA CO., LTD.
Aichi
JP
|
Family ID: |
38655296 |
Appl. No.: |
12/259627 |
Filed: |
October 28, 2008 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP2007/058161 |
Apr 13, 2007 |
|
|
|
12259627 |
|
|
|
|
Current U.S.
Class: |
473/157 ;
473/251 |
Current CPC
Class: |
A63B 69/3676
20130101 |
Class at
Publication: |
473/157 ;
473/251 |
International
Class: |
A63B 69/36 20060101
A63B069/36 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 28, 2006 |
JP |
2006-125151 |
Claims
1. A golf putting trainer in which a ball rolling groove is formed,
a ball placing portion is provided on a base-end side of the ball
rolling groove, and a golf ball placed on the ball placing portion
is putted and rolled along a ball rolling groove, the golf putting
trainer being characterized in that the ball rolling groove has a
groove width of 9 mm to 5 mm, a transverse sectional shape of the
ball rolling groove is formed into a gently concave curved surface
in which the golf ball is supported at one point, and a percentage
in which the golf ball breaks away from the ball rolling groove is
decreased in a ball hitting angle having an error lower than 2
degrees when a putting force, with which the golf ball is rolled to
about 1.5 m to 2 m on the green, is applied.
2. A golf putting trainer in which a ball rolling groove is formed,
a ball placing portion is provided on a base-end side of the ball
rolling groove, and a golf ball placed on the ball placing portion
is putted and rolled along the ball rolling groove, the golf
putting trainer being characterized in that the ball rolling groove
has a groove width of 12 mm to 10 mm, a transverse sectional shape
of the ball rolling groove is formed into a gently concave curved
surface in which a golf ball is supported at one point, and the
percentage in which a golf ball breaks away from the ball rolling
groove is decreased in a ball hitting angle having an error not
more than 2 degrees when a putting force with which a golf ball is
rolled to about 1.5 m to 2 m on green is applied.
3. The golf putting trainer according to claim 1, characterized in
that the curved surface is formed into an arc surface whose section
becomes an arc shape.
4. The golf putting trainer according to claim 1, characterized in
that the curved surface is formed into an elliptical surface whose
section becomes an elliptical shape.
5. The golf putting trainer according to claim 1, characterized in
that the curved surface includes a flat surface located in a groove
bottom of the ball rolling groove and a slope rising from both
sides of the flat surface.
6. The golf putting trainer according to claim 1, characterized in
that flat trimming surfaces are provided along groove edges on both
sides of a ball rolling groove.
7. The golf putting trainer according to claim 6, characterized in
that a downward sloping surface is formed from an edge of a flat
surface to an edge of a plate material.
8. The golf putting trainer according to claim 1, characterized in
that at least inside the ball rolling groove is lusterless.
9. The golf putting trainer according to claim 1, characterized in
that a mark having a diameter smaller than a diameter of a golf
ball is provided around a ball placing portion.
10. A golf putting trainer in which a ball rolling groove is
formed, a ball placing portion is provided on a base-end side of
the ball rolling groove, and a golf ball placed on the ball placing
portion is putted and rolled along a ball rolling groove, the golf
putting trainer being characterized in that a transverse sectional
shape of the ball rolling groove is formed into an arc shape having
a curvature radius of 100 mm, the ball rolling groove has a groove
width of 9 mm to 5 mm, and a percentage in which a golf ball breaks
away from a ball rolling groove is decreased in a ball hitting
angle having an error lower than 2 degrees when a putting force
with which a golf ball is rolled to about 1.5 m to 2 m on green is
applied.
11. A golf putting trainer in which a ball rolling groove is
formed, a ball placing portion is provided on a base-end side of
the ball rolling groove, and a golf ball placed on the ball placing
portion is putted and rolled along a ball rolling groove, the golf
putting trainer being characterized in that a transverse sectional
shape of the ball rolling groove is formed into an arc shape having
a curvature radius of 60 mm, the ball rolling groove has a groove
width of 9 mm to 5 mm, and a percentage in which a golf ball breaks
away from the ball rolling groove is decreased in a ball hitting
angle having an error lower than 2 degrees when a putting force
with which a golf ball is rolled to about 1.5 m to 2 m on green is
applied.
12. The golf putting trainer according to claim 1, characterized in
that the golf putting trainer is made of metal.
13. The golf putting trainer according to claim 2, characterized in
that the curved surface is formed into an arc surface whose section
becomes an arc shape.
14. The golf putting trainer according to claim 2, characterized in
that the curved surface is formed into an elliptical surface whose
section becomes an elliptical shape.
15. The golf putting trainer according to claim 2, characterized in
that the curved surface includes a flat surface located in a groove
bottom of the ball rolling groove and a slope rising from both
sides of the flat surface.
16. The golf putting trainer according to claim 2, characterized in
that flat trimming surfaces are provided along groove edges on both
sides of a ball rolling groove.
17. The golf putting trainer according to claim 2, characterized in
that at least inside the ball rolling groove is lusterless.
18. The golf putting trainer according to claim 2, characterized in
that a mark having a diameter smaller than a diameter of a golf
ball is provided around a ball placing portion.
19. The golf putting trainer according to claim 2, characterized in
that the golf putting trainer is made of metal.
Description
TECHNICAL FIELD
[0001] The present invention relates to a golf putting trainer.
BACKGROUND ART
[0002] As shown in FIG. 10, in practicing golf putting, a golfer
has an effective practice in which the golfer uses a putter P to
hit a golf ball B toward a hole H at a distance of about 1.5 m from
the hole H.
[0003] In consideration of the hole H having diameter of about
107.9 mm, as shown in FIG. 10, the struck golf ball B has a chance
to go in hole H when an internal angle .theta. (hereinafter
referred to as error .theta. of a ball hitting angle) formed
between an actual hitting direction U of the golf ball B and a
straight line L connecting the hole H and the golf ball B placed at
a hitting position is not more than about 2 degrees.
[0004] On the other hand, a golf putting trainer has been proposed.
FIG. 11 shows an outline of a golf putting trainer 100 disclosed in
Patent Document 1. FIG. 12 shows a transverse section of FIG.
11.
[0005] Patent Document 1: Japanese Patent Publication Laid-Open No.
H9-234262A
[0006] The putting trainer 100 has a configuration in which a rail
102 is provided on a base 101. It is assumed that a hole is located
on an extension of the rail 102, and the golfer practices hitting a
golf ball B straightforward toward the hole such that the golf ball
B does not drop out from the rail 102.
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0007] However, the golf putting trainer 100 disclosed in Patent
Document 1 is not intended to practice putting such that the error
of the ball hitting angle falls within about 2 degrees or less.
Therefore, the golf putting trainer 100 cannot be used when the
golfer practices putting while taking notice that the ball hitting
angle falls within about 2 degrees or less.
[0008] In view of the foregoing, an object of the invention is to
provide a putting trainer in which the golfer can practice putting
while taking notice that the ball hitting angle falls within about
2 degrees or less.
Means for Solving the Problems
[0009] The invention according to claim 1 is a golf putting trainer
in which a ball rolling groove is formed, a ball placing portion is
provided on a base-end side of the ball rolling groove, and a golf
ball placed on the ball placing portion is putted and rolled along
the ball rolling groove, characterized in that the ball rolling
groove has a groove width of 9 mm to 5 mm, a transverse sectional
shape of the ball rolling groove is formed into a gently concave
curved surface in which the golf ball is supported at one point,
and a percentage in which the golf ball breaks away from the ball
rolling groove is decreased in a ball hitting angle having an error
lower than 2 degrees when a putting force with which the golf ball
is rolled to about 1.5 m to 2 m on green is applied.
[0010] The invention according to claim 2 is a golf putting trainer
in which a ball rolling groove is formed, a ball placing portion is
provided on a base-end side of the ball rolling groove, and a golf
ball placed on the ball placing portion is putted and rolled along
the ball rolling groove, characterized in that the ball rolling
groove has a groove width of 12 mm to 10 mm, a transverse sectional
shape of the ball rolling groove is formed into a gently concave
curved surface in which the golf ball is supported at one point,
and a percentage in which the golf ball breaks away from the ball
rolling groove is decreased in a ball hitting angle having an error
not more than 2 degrees when a putting force, with which the golf
ball is rolled to about 1.5 m to 2 m on the green, is applied.
[0011] In the golf putting trainer according to claim 1 or 2, the
invention according to claim 3 is characterized in that the curved
surface is formed into an arc surface whose section becomes an arc
shape.
[0012] In the golf putting trainer according to any one of claims 1
to 3, the invention according to claim 4 is characterized in that
the curved surface is formed into an elliptical surface whose
section becomes an elliptical shape.
[0013] In the golf putting trainer according to claim 1 or 2, the
invention according to claim 5 is characterized in that the curved
surface includes a flat surface located in a groove bottom of the
ball rolling groove and a slope rising from both sides of the flat
surface.
[0014] In the golf putting trainer according to any one of claims 1
to 5, the invention according to claim 6 is characterized in that
flat trimming surfaces are provided along groove edges on both
sides of the ball rolling groove.
[0015] In the golf putting trainer according to claim 6, the
invention according to claim 7 is characterized in that a downward
sloping surface is formed from an edge of the flat surface to an
edge of a plate material.
[0016] In the golf putting trainer according to any one of claims 1
to 7, the invention according to claim 8 is characterized in that
at least one ball rolling groove is lusterless inside.
[0017] In the golf putting trainer according to any one of claims 1
to 8, the invention according to claim 9 is characterized in that a
mark having a diameter smaller than a diameter of the golf ball is
provided around the ball placing portion.
[0018] The invention according to claim 10 is a golf putting
trainer in which a ball rolling groove is formed, a ball placing
portion is provided on a base-end side of the ball rolling groove,
and a golf ball placed on the ball placing portion is putted and
rolled along the ball rolling groove, characterized in that a
transverse sectional shape of the ball rolling groove is formed
into an arc shape having a curvature radius of 100 mm, the ball
rolling groove has a groove width of 1.5 mm to 5 mm, and a
percentage in which the golf ball breaks away from the ball rolling
groove is decreased in a ball hitting angle having an error lower
than 2 degrees when a putting force, with which the golf ball is
rolled to about 1.5 m to 2 m on the green, is applied.
[0019] The invention according to claim 11 is a golf putting
trainer in which a ball rolling groove is formed, a ball placing
portion is provided on a base-end side of the ball rolling groove,
and a golf ball placed on the ball placing portion is putted and
rolled along the ball rolling groove, characterized in that a
transverse sectional shape of the ball rolling groove is formed
into an arc shape having a curvature radius of 60 mm, the ball
rolling groove has a groove width of 9 mm to 5 mm, and a percentage
in which the golf ball breaks away from the ball rolling groove is
decreased in a ball hitting angle having an error lower than 2
degrees when a putting force, with which the golf ball is rolled to
about 1.5 m to 2 m on the green, is applied.
[0020] In the golf putting trainer according to any one of claims 1
to 11, the invention according to claim 12 is characterized in that
the golf putting trainer is made of a metal.
EFFECTS OF THE INVENTION
[0021] Using the putting trainer according to claim 1, a
professional and an advanced-level amateur golfer can accurately
practice their putting such that the error of the ball hitting
angle is lower than 2 degrees.
[0022] Using the putting trainer according to claim 2, a beginner
and an intermediate golfer can practice putting such that the error
of the ball hitting angle is not more than 2 degrees.
[0023] According to the invention in claim 3, the ball rolling
groove can be formed by providing the groove whose section is
formed into the arc shape in the upper surface of the base.
[0024] According to the invention in claim 4, the ball rolling
groove can be formed by providing the groove whose section is
formed into the elliptical shape in the upper surface of the
base.
[0025] According to the invention in claim 5, the inclination of
the slope can be adjusted such that the golf ball does not break
away from the rolling groove when the error of the ball hitting
angle is lower than 2 degrees or not more than 2 degrees.
[0026] According to the invention in claim 6, the flat trimming
surfaces are provided along the edges of the ball rolling groove to
highlight the existence of the ball rolling groove, which allows
the golfer to concentrate nerves on the ball rolling groove.
[0027] According to the invention in claim 7, the golf ball
breaking away from the ball rolling groove is rolled on the
downward sloping surface, which allows the golfer to clearly see
the golf ball breaking away from the ball rolling groove.
[0028] According to the invention in claim 8, because the ball
rolling groove has a lusterless surface, the golf ball can be
rolled in the ball rolling groove while slipping of the golf ball
is prevented.
[0029] According to the invention in claim 9, an address stance is
corrected such that a positional relationship between the golf ball
and the mark becomes proper, which allows the golfer to take the
proper address stance.
[0030] According to the invention in claim 10, using the putting
trainer, the golfer practices putting such that the golf ball does
not break away from the ball rolling groove, which allows the ball
hitting angle to become lower than 2 degrees. In the putting
trainer, the ball rolling groove is formed, and the ball rolling
groove has the arc-shape transverse section, the curvature radius
of 100 mm, and the groove width of 9 mm to 5 mm.
[0031] According to the invention in claim 11, using the putting
trainer, the golfer practices putting such that the golf ball does
not break away from the ball rolling groove, which allows the ball
hitting angle to become lower than 2 degrees. In the putting
trainer, the ball rolling groove is formed, and the ball rolling
groove has the arc-shape transverse section, the curvature radius
of 60 mm, and the groove width of 9 mm to 5 mm.
[0032] Accordingly, in the invention according to claim 12, the
golf putting trainer can accurately be molded with an extrusion
molding die.
BEST MODE FOR CARRYING OUT THE INVENTION
[0033] FIG. 1 is a plan view of a putting trainer according to an
embodiment of the invention. FIG. 2 shows a transverse section of
FIG. 1.
[0034] As shown in FIG. 1, a base 2 of a golf putting trainer 1 is
formed into a long plate shape. In an upper surface of the base 2,
a ball rolling groove 3 is formed toward a lengthwise direction in
the center of a width direction of the base 2. As shown in FIG. 1,
the ball rolling groove 3 can be formed from a base end of the base
2 to a leading end. Alternatively, the ball rolling groove 3 may be
formed from an arbitrary position on a base-end side of the base 2
to the leading end of the base 2.
[0035] As shown in FIG. 1, the ball rolling groove 3 is formed so
as to have the same groove width from the base end to the leading
end. As shown in FIG. 2, the transverse section of the ball rolling
groove 3 is formed into an arc shape.
[0036] A ball placing portion 4 is formed on the base-end side of
the ball rolling groove 3. The ball placing portion 4 is a region
where the golf ball B is placed in address. The golf ball B placed
on the ball placing portion 4 is hit along the ball rolling groove
3. The ball placing portion 4 includes a hole 5 which pierces
through a surface to a backside of the base 1 and a circular mark 6
provided around the hole 5. A diameter of the hole 5 is smaller
than a diameter of the golf ball B such that the golf ball B is
placed on the ball placing portion 4 without dropping out from the
ball placing portion 4. A diameter of the mark 6 is slightly
smaller than the diameter of the golf ball B shown by an alternate
long and two short dashes line of FIG. 1, and the mark 6 and the
hole 5 are provided in a concentric fashion. The color such as
black can be given to the mark 6. The mark 6 is required in taking
a proper address stance.
[0037] That is, for example, a right-handed golfer sees the golf
ball B with the left eye from immediately above the golf ball B
placed on the ball placing portion 4, and the golfer corrects the
stance thereof so as not to be able to see the mark 6 in all
circumferences. Therefore, the golfer can take the proper address
stance.
[0038] As shown in FIG. 2, in the case where the ball rolling
groove 3 is formed into an arc transverse sectional shape, a
numerical value not lower than a radius of the golf ball B is taken
for a curvature radius of the transverse section of the ball
rolling groove 3 such that the golf ball B can be supported at one
point while the golf ball B is placed in the ball rolling groove 3
as shown in FIG. 3. The dimensions such as a groove width, a depth,
and a curvature radius of the ball rolling groove 3 are set at
numerical values such that the golf ball B does not break away from
the ball rolling groove 3, when the error .theta. of the ball
hitting angle is lower than 2 degrees as shown in FIG. 1. The
specific numerical values of the dimensions such as a groove width,
a depth, and a curvature radius of the ball rolling groove 3 are
described later.
[0039] As shown in FIG. 1, trimming surfaces 7 and 7 are formed
along the lengthwise direction at groove edges on both sides of the
ball rolling groove 3. The trimming surface 7 is formed into a flat
surface. The trimming surfaces 7 and 7 are connected to sloping
surfaces 8 while steps 7a are interposed therebetween, and the
sloping surface 8 is connected to base 1 while inclined
downwards.
[0040] At least the ball rolling groove 3 has a lusterless surface,
and the ball rolling groove 3 has a surface structure in which a
slip of the golf ball B can be prevented. The whole surface of the
base 2 including the golf ball rolling groove 3 may be formed
lusterless. Pear skin can be cited as an example of the lusterless
means.
[0041] FIGS. 4 to 6 are tables showing results of experiments in
which the golf ball B is hit for ball rolling grooves 3 having
different dimensions.
[0042] In the case of FIG. 4, the ball rolling groove 3 has a
length of 100 cm, and the ball is mechanically hit using a
well-known apparatus with a putting force with which the ball can
be rolled on the green to 150 cm or 180 cm. In other words, FIG. 4
shows the case in which the golf ball B is hit with the putting
force corresponding to a force with which the golf ball B is
actually putted on the green. FIG. 4 shows the experimental result
in the case where the ball rolling groove 3 has the curvature of
100 mm in the transverse section, the groove width of 3 mm to 12
mm, and the groove depth of 0.011 mm to 0.180 mm.
[0043] As shown in FIG. 1, in the experiment for hitting the golf
ball B, the golf ball B placed on the ball placing portion 4 is hit
such that the error .theta. of the ball hitting angle becomes 0, 1,
and 2 degrees, thereby making a determination whether or not the
golf ball B breaks away from the golf ball rolling groove 3. The
experiment shows the case in which the golf ball B placed on the
ball placing portion 4 is mechanically hit using a well-known
apparatus with the putting force with which the golf ball B is
rolled to about 1.5 m to 2 m. That is, the experiment shows the
case in which the golf ball B is hit with the putting force
corresponding to a force with which the golf ball B is actually
putted on the green.
[0044] In the table of FIG. 4, a mark "X" indicates that the golf
ball B breaks away from the ball rolling groove 3, and a mark
".largecircle." indicates that the golf ball does not break away
from the ball rolling groove.
[0045] FIG. 5 shows the experimental result similar to that of FIG.
4 in the case where the ball rolling groove 3 has the curvature of
60 mm in the transverse section, the groove width of 3 mm to 12 mm,
and the groove depth of 0.019 mm to 0.301 mm.
[0046] FIG. 6 shows the experimental result similar to that of FIG.
4 in the case where the ball rolling groove 3 has the curvature of
180 mm in the transverse section, the groove width of 3 mm to 12
mm, and the groove depth of 0.006 mm to 0.100 mm.
[0047] As shown in FIGS. 4 and 5, in the case where the error
.theta. of the ball hitting angle is lower than 2 degrees while the
groove width of the ball rolling groove 3 ranges from 5 mm to 9 mm,
the percentage in which the golf ball B breaks away from the ball
rolling groove 3 is small. However, the percentage in which the
golf ball B breaks away from the ball rolling groove 3 becomes
large in the case where the error .theta. of the ball hitting angle
is higher than 2 degrees.
[0048] Therefore, in the case where the groove width of the ball
rolling groove 3 ranges from 5 mm to 9 mm, the golf ball B is hit
so as not to break away from the ball rolling groove 3, whereby the
golfer can practice putting while taking notice that the error
.theta. of the ball hitting angle is lower than 2 degrees. Thus,
the golfer practices putting such that the error .theta. of the
ball hitting angle is lower than 2 degrees, whereby the golfer
probably sinks the golf ball B in the hole on the actual green.
Thus, the golfer practices accurate putting such that the error
.theta. of the ball hitting angle is lower than 2 degrees is
suitable to training professional and advanced-level amateur
golfers.
[0049] As shown in FIGS. 4 and 5, the percentage in which the golf
ball B breaks away from the ball rolling groove 3 is small, in the
case where the error .theta. of the ball hitting angle is not more
than 2 degrees while the groove width of the ball rolling groove 3
ranges from 10 mm to 12 mm.
[0050] Therefore, in the case where the ball rolling groove 3 has
the curvature radius of 60 mm or 100 mm and the groove width of 10
mm to 12 mm, the golfer has the practice in which the golfer hits a
golf ball B such that the golf ball B does not break away from the
ball rolling groove 3, whereby the golfer can practice putting
while taking notice that the error .theta. of the ball hitting
angle is not more than 2 degrees. The golfer practices putting such
that the error .theta. of the ball hitting angle is not more than 2
degrees and thus suitable for training beginner and intermediate
golfers.
[0051] As shown in FIG. 6, in the case where the ball rolling
groove 3 has the curvature radius of 180 mm and the groove width of
9 mm to 12 mm, the percentage in which the golf ball B breaks away
from the ball rolling groove 3 is small when the error .theta. of
the ball hitting angle is lower than 2 degrees. However, the
percentage in which the golf ball B breaks away from the ball
rolling groove 3 will become large, when the error .theta. of the
ball hitting angle is not lower than 2 degrees.
[0052] Therefore, in the case where the ball rolling groove 3 has
the curvature radius of 180 mm and the groove width of 9 mm to 12
mm, the golfer has the practice in which the golfer hits a golf
ball B such that the golf ball B does not break away from the ball
rolling groove 3, whereby the golfer can practice putting while
taking notice that the golf ball B is probably sunk in the hole on
the actual green because of the ball hitting angle having the error
.theta. lower than 2 degrees. The accurate putting training is
suitable for professional and advanced-level amateur golfers.
[0053] In the above-described experiments, the experiment is not
performed between the curvature radius of 60 mm (shown in FIG. 4)
and the curvature radius of 100 mm (shown in FIG. 5). However, in
the case where the golf ball rolling groove 3 has the same groove
width, the groove depth becomes shallower as the curvature radius
is enlarged, and the golf ball B easily breaks away from the ball
rolling groove 3. However, the similar experimental result is
obtained in the case of the curvature radius of 60 mm (shown in
FIG. 4) and in the case of the curvature radius of 100 mm (shown in
FIG. 5). Therefore, it is determined that the similar experimental
result is obtained at least between the curvature radius of 60 mm
(shown in FIG. 4) and the curvature radius of 100 mm (shown in FIG.
5).
[0054] In other words, as described in claim 1, when the putting
force with which the golf ball is rolled to about 1.5 m to 2 m on
the green is applied, the shape having the small percentage in
which the golf ball B breaks away from the ball rolling groove 3
while the error .theta. of the ball hitting angle is lower than 2
degrees corresponds to the ball rolling groove 3 having the
circular transverse sectional shape, the groove width of 5 mm to 9
mm, and the curvature radius of 60 mm to 100 mm.
[0055] As shown in FIG. 6, in the case where the ball rolling
groove 3 has the curvature radius of 180 mm and the groove width of
9 mm to 12 mm, the percentage in which the golf ball B breaks away
from the ball rolling groove 3 is small when the error .theta. of
the ball hitting angle is lower than 2 degrees. Therefore, the ball
rolling groove 3 having the ranges corresponds to the ball rolling
groove according to claim 1.
[0056] As described in claim 2, when the putting force with which
the golf ball is rolled to about 1.5 m to 2 m on the green is
applied, the shape having the small percentage in which the golf
ball B breaks away from the ball rolling groove 3 while the error
.theta. of the ball hitting angle is not more than 2 degrees
corresponds to the ball rolling groove 3 having the circular
transverse sectional shape, the groove width of 10 mm to 12 mm, and
the curvature radius of 60 mm to 100 mm. In the case of the
curvature radius of 100 mm, the shape in which the groove width of
the ball rolling groove 3 ranges from 10 mm to 12 mm can satisfy
the requirements. In the case where the ball rolling groove 3 has
the above-described mode, the putting training is suitable for the
beginner and intermediate golfer.
[0057] Next, the action will be described. As shown in FIG. 3, the
golf ball B is supported at one point by the ball rolling groove 3.
Therefore, the golf ball B is rolled in the ball rolling groove 3
along an axial center direction of the ball rolling groove 3 while
unstably and easily rolled in a width direction of the ball rolling
groove 3. Additionally, due to the fact a side face 3a of the ball
rolling groove 3 is formed into an uphill sloping surface, a
drawing-back force F acts on the golf ball B so as to draw back the
golf ball B toward the center direction of the ball rolling groove
3 based on the gravity acting on the golf ball B, when the golf
ball B breaks away from the ball rolling groove 3. The drawing-back
force F reproduces the status in which the golf ball B is actually
rolled on the green.
[0058] In other words, as shown in FIG. 7, in the case where the
golf ball B is curved leftward on the actual green, the golf ball B
is rolled while bending down the lawn S. At this point, the golf
ball B is subject to a reactive force M shown by an arrow from the
rising lawn S. This state is continued while the golf ball B rolls
forward swaying right and left. The reactive force M shown by the
arrow corresponds to the drawing-back force F of FIG. 3. Thus, in
the embodiment, due to the fact that the golf ball B is rolled
forward while swaying right and left in the golf ball rolling
groove 3, the golf ball B is brought close to the state in which
the golf ball B is rolled on the actual green, and the golfer can
practice putting while feeling a realistic sensation. Additionally
the ball rolling groove 3 is formed lusterless. Therefore, the
golfer can practice putting in a sense close to the case in which
the golfer sinks the putt on the lawn by a synergistic effect of
the lusterless effect and the effect of the one-point support
structure.
[0059] As shown in FIGS. 4 to 6, the ball rolling groove 3 has the
groove width as thin as 12 mm or less, and the flat trimming
surface 7 is provided along the grove edge of golf ball rolling
groove 3, and the trimming surface 7 is visible while floating from
the sloping surface by the step 7a. Therefore, the golfer can
practice the putting while seeing the thin ball rolling groove 3
having the thin width and the trimming surfaces 7 and 7 to
concentrate nerves on the ball rolling groove 3.
[0060] Additionally the downward sloping surface 8 is formed from
the trimming surface 7 to the edge of the base 2. Therefore, when
the golf ball B breaks away from the ball rolling groove 3, the
golfer sees the golf ball B rolling down in the sloping surface 8,
so that the golfer can clearly recognize that the golf ball B
breaks away from the ball rolling groove 3.
[0061] FIG. 8 shows a second embodiment. The second embodiment is
characterized in that the transverse sectional shape of the ball
rolling groove 3 is formed into an elliptical shape. In the second
embodiment, because the transverse sectional shape of the ball
rolling groove 3 is formed into the elliptical shape, a slope 12
rising from a groove bottom 11 of the ball rolling groove 3 has a
curvature radius smaller than a curvature radius of the groove
bottom 11.
[0062] The curvature radius in the transverse section of the ball
rolling groove 3 is a main factor defining whether or not the golf
ball B drops out from the ball rolling groove 3. The reason will be
described below. For example, in comparison of the experimental
results for the ball rolling groove 3 of FIG. 4 having the groove
width of 6 mm and the groove depth of 0.045 mm and the ball rolling
groove 3 of FIG. 6 having the groove width of 8 mm and the groove
depth of 0.044 mm, although the ball rolling groove 3 of FIG. 4 is
substantially similar to the ball rolling groove 3 of FIG. 6 in the
groove depth, the ball rolling groove 3 of FIG. 6 is larger than
the ball rolling groove of FIG. 4 in the groove width, so that the
golf ball B would hardly break away from the ball rolling groove 3
in the ball rolling groove 3 of FIG. 6. However, actually the ball
rolling groove 3 of FIG. 6 has the higher percentage in which the
golf ball B breaks away from the ball rolling groove 3.
[0063] This is attributed to the following facts. That is, in the
ball rolling groove 3 of FIG. 4, the curvature radius in the
transverse section is smaller, the side face has a steep slope, and
the golf ball B is rebounded by the side face having the steep
slope, thereby preventing the golf ball B from breaking away from
the ball rolling groove 3, when the golf ball B almost breaks away
from the ball rolling groove 3. Thus, when the error .theta. of the
ball hitting angle is set at the desired value, the adjustment can
be made by changing the curvature radius of the side face of the
ball rolling groove 3 such that the golf ball B breaks away from
the ball rolling groove 3.
[0064] Accordingly, when the transverse sectional shape of the ball
rolling groove 3 is formed into the circular shape as shown in
FIGS. 4 and 5, in the case where the ball rolling groove 3 has the
groove width of 5 mm to 9 mm while the error .theta. of the ball
hitting angle is not more than 2 degrees, the percentage in which
the golf ball B breaks away from the ball rolling groove 3 is
large. However, when the transverse sectional shape of the ball
rolling groove 3 is formed into the elliptical shape as shown in
FIG. 8, even if the error .theta. of the ball hitting angle is not
lower than 2 degrees, the golf ball B hardly breaks away from the
ball rolling groove 3. Thus, even if the error .theta. of the ball
hitting angle is not more than 2 degrees, the transverse sectional
shape of the ball rolling groove 3 is formed into the elliptical
shape such that the golf ball B does not break away from the ball
rolling groove 3, which allows the putting trainer of the second
embodiment to be utilized for the putting trainings of the beginner
and intermediate golfer.
[0065] FIG. 9 shows a third embodiment. The third embodiment is
characterized in that the transverse sectional shape of the ball
rolling groove 3 is formed into a trapezoidal shape by a flat
surface 21 located in the groove bottom and slopes 22 rising from
both sides of the flat surface 21. In the third embodiment, a
rising angle of the slope 22 is adjusted as follows; even if the
error .theta. of the ball hitting angle is not lower than 2
degrees, the golf ball B is rebounded by hitting the slope 22 of
the ball rolling groove 3, and the golf ball B can be rolled in the
ball rolling groove 3 while hardly breaking away from the ball
rolling groove 3.
BRIEF DESCRIPTION OF THE DRAWINGS
[0066] FIG. 1 is a flat view of a putting trainer according to an
embodiment of the invention.
[0067] FIG. 2 is a transverse sectional view of FIG. 1.
[0068] FIG. 3 is a left side view of FIG. 1 showing a state in
which a golf ball is placed in the ball rolling groove.
[0069] FIG. 4 is a table showing experimental results.
[0070] FIG. 5 is a table showing experimental results.
[0071] FIG. 6 is a table showing experimental results.
[0072] FIG. 7 is a view explaining the action showing a state in
which a golf ball is placed on the lawn.
[0073] FIG. 8 is a transverse sectional view of a ball rolling
groove (second embodiment).
[0074] FIG. 9 is a transverse sectional view of a ball rolling
groove (third embodiment).
[0075] FIG. 10 is a view showing a positional relationship between
the putter, golf ball, and hole.
[0076] FIG. 11 is a view showing an appearance of a putting trainer
(conventional technique).
[0077] FIG. 12 is a transverse sectional view of FIG. 11
(conventional technique).
DESCRIPTION OF REFERENCE NUMERALS
[0078] 1 putting trainer [0079] 2 base [0080] 3 ball rolling groove
[0081] 4 mark [0082] 7 trimming surface [0083] 7a step [0084] 8
down sloping surface [0085] B golf ball [0086] S lawn glass [0087]
.theta. error of ball hitting angle
* * * * *