U.S. patent application number 12/792087 was filed with the patent office on 2011-12-08 for golf ball.
This patent application is currently assigned to BRIDGESTONE SPORTS CO., LTD.. Invention is credited to Takuma Nakagawa, Katsunori Sato.
Application Number | 20110300971 12/792087 |
Document ID | / |
Family ID | 45064881 |
Filed Date | 2011-12-08 |
United States Patent
Application |
20110300971 |
Kind Code |
A1 |
Nakagawa; Takuma ; et
al. |
December 8, 2011 |
GOLF BALL
Abstract
A golf ball includes a land part representing a symbol, and
dimples defining the land part by outer edges thereof and disposed
on a surface of the golf ball. The symbol represented by the land
part may include numerals, letters, pictures, or logo. The dimples
defining the land part by outer edges thereof can include at least
two non-circular dimples. The dimples defining the land part by
outer edges thereof can include a dimple having a wall surface
having a linear shape extending substantially in a depth direction,
the wall surfaces being adjacent to the land part representing the
symbol.
Inventors: |
Nakagawa; Takuma;
(Chichibu-shi, JP) ; Sato; Katsunori;
(Chichibu-shi, JP) |
Assignee: |
BRIDGESTONE SPORTS CO.,
LTD.
Tokyo
JP
|
Family ID: |
45064881 |
Appl. No.: |
12/792087 |
Filed: |
June 2, 2010 |
Current U.S.
Class: |
473/378 |
Current CPC
Class: |
A63B 37/0007
20130101 |
Class at
Publication: |
473/378 |
International
Class: |
A63B 37/14 20060101
A63B037/14 |
Claims
1. A golf ball comprising: a land part representing a symbol; and
dimples defining the land part by outer edges thereof and disposed
on a surface of the golf ball.
2. The golf ball according to claim 1, wherein the dimples defining
the land part by the outer edges thereof comprise at least two
non-circular dimples.
3. The golf ball according to claim 1, wherein the dimples defining
the land part by the outer edges thereof comprise at least three
non-circular dimples.
4. The golf ball according to claim 1, wherein the dimples defining
the land part by the outer edges thereof comprise a dimple having a
wall surface having a linear shape extending substantially in a
depth direction, the wall surface being adjacent to the land part
representing the symbol.
5. The golf ball according to claim 1, wherein the dimples defining
the land part comprises a dimple having a flat bottom surface.
6. The golf ball according to claim 1, wherein a pole point of the
golf ball is arranged at a position within the land part.
7. The golf ball according to claim 1, wherein the symbol comprises
a numeral.
8. The golf ball according to claim 1, wherein the symbol comprises
a letter.
9. The golf ball according to claim 1, wherein the symbol comprises
a picture.
10. The golf ball according to claim 1, wherein the symbol
comprises a logo.
11. The golf ball according to claim 1, wherein the symbol
represents a company.
12. The golf ball according to claim 1, wherein the symbol
represents a product.
13. The golf ball according to claim 1, wherein the symbol
represents a mascot character.
14. The golf ball according to claim 1, comprising at least two of
the land parts representing symbols.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a golf ball having a
symbol.
[0002] Markings such as symbols, numerals, letters, and patterns
are often applied on the surfaces of golf balls. Methods of
applying such markings to the surface of a golf ball include
methods of printing or transferring ink onto the surface of a golf
ball and methods of engraving on the surface of the golf ball.
[0003] Because plural dimples are disposed at a high density on the
surface of the golf ball, the former method has a problem of a
tendency to yield poor printing. With the latter method, there is a
problem of difficulty in engraving a marking such as a logo having
a complex shape. Also, because the edges of the recessed parts are
sharply pointed, there is the problem of an adverse affect on the
aerodynamic characteristics of the golf ball.
[0004] U.S. Pat. No. 7,303,492 discloses a golf ball in which
dimples are made into the shape of text letters or characters or
other symbols. When a symbol is constituted by dimples, however,
the symbol itself becomes very large, and in order to mark the
surface of the golf ball with the desired symbol, there is the
problem of an excessively large influence on the aerodynamic
characteristics of the golf ball.
[0005] U.S. Pat. No. 7,273,426 and U.S. Pat. No. 7,618,332 disclose
golf balls in which recesses having substantially uniform depth
from the surface are formed in plural dimples and the land parts
therebetween, wherein these recesses form patterns such as letters
or graphic forms. The engraved marking to a depth that is
substantially uniform can be formed simultaneously with the dimples
when the cover layer of the golf ball is injection molded using a
mold.
[0006] When the cover layer of a golf ball is molded, burrs often
can occur at locations corresponding to the support pins and vent
pins of the mold and to the seams. Because the presence of burrs
greatly worsens the aerodynamic characteristics of the golf ball,
it is necessary to remove them by grinding. When the golf ball is
ground to remove burrs, there is the problem in that the depth of
the engraved marking formed in the surface thereof is reduced,
leading to the risk of destruction of the shape of the engraved
marking.
SUMMARY OF THE INVENTION
[0007] Accordingly, an object of the present invention is to
provide a golf ball, which is based on a technological concept
completely different from conventional dimples and engraved
markings representing symbols, thereby providing a golf ball with a
novel appearance.
[0008] A golf ball according to the present invention includes a
land part representing a symbol, and dimples defining the land part
by outer edges thereof and disposed on a surface of the golf ball.
The symbol may include a numeral, a letter, a picture, or a logo.
The symbol may represent a company, a trademark, a person, or a
mascot character. The golf ball according to the present invention
may include at least two of the land parts representing symbols.
The dimples defining the land part by outer edges thereof
preferably include at least two non-circular dimples.
[0009] The dimples defining the land part by outer edges thereof
may include a dimple having a wall surface having a linear shape
extending substantially in a depth direction, the wall surface
being adjacent to the land part representing the symbol. The
dimples defining the land part may include a dimple having a flat
bottom surface. Preferably, a pole point of the golf ball may be
arranged at a position within the land part.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a view showing a golf ball according to an
embodiment of the present invention.
[0011] FIG. 2(a) is a cross-sectional view showing an example of a
dimple that defines a land part representing a symbol by its outer
edge. FIG. 2(b) is a cross-sectional view showing another example
of a dimple that defines a land part representing a symbol by its
outer edge. FIG. 2(c) is a cross-sectional view of yet another
example of a dimple that defines a land part representing a symbol
by its outer edge.
[0012] FIG. 3 is a view illustrating a method of arranging dimples
on the golf ball shown in FIG. 1.
[0013] FIG. 4 is a view showing a land part representing a symbol
which is formed on the surface of a golf ball according to another
embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] Embodiments of the present invention will be described below
with reference to the drawings.
[0015] As shown in FIG. 1, plural dimples 10 are disposed on the
surface of a golf ball 1. A golf ball surface between the plural
dimples 10 is referred to herein with regard to the present
invention as a land part 20. The land part 20 has a spherically
curved surface that is a part of a surface of an imaginary sphere
having its center at the center of the golf ball 1.
[0016] In general, the land part 20 that is surrounded by a
plurality of circular dimples has an irregular and meaningless
shape. In this embodiment, however, as shown in FIG. 1, a land part
22 has a shape representing the logo "Tour Stage," which is a
trademark of Bridgestone Sports Co., Ltd. The land part 22
representing the logo is defined by the outer edges of non-circular
dimples 12.
[0017] A non-circular dimple, as the term is used in this
specification, refers to a dimple having an outer edge, which is a
boundary line 13 between a land part and a dimple, and which is not
circular. The non-circular dimple, for example, includes a dimple
having a bent part in the boundary line 13, and a dimple having the
boundary line 13 formed by a curved part and a linear part.
[0018] As shown in FIG. 2(a), the cross-section of a non-circular
dimple 12, in the same manner as a usual circular dimple, has a
bottom surface 14 that is smoothly curved from the boundary line 13
with land parts 20, 22 toward the deepest position in the dimple
center. As shown in FIG. 2(b), a wall surface 15 is preferably
provided that is adjacent to the boundary line 13a with the land
part 22 representing a logo, and having a shape that is
substantially a straight line in the depth direction. By providing
such a wall surface 15, because the difference in height at the
dimple surface at the boundary line 13a between the dimple 12 and
the land part 22 that represents the logo becomes prominent, the
symbol such as a logo or the like represented by the land part 22
stands out visually.
[0019] In the case in which the wall surface 15 is provided, the
part of the bottom surface 16 of the dimple from the position at
which the dimple is deepest up until a part that is adjacent to the
wall surface 15 may be made flat. Also, a smooth curve is
maintained from the position at which the dimple is deepest up
until the boundary line 13b with the usual land part 20. It will be
naturally understood that, as shown in FIG. 2(c), the wall surface
15 with a shape that is substantially a straight line in the depth
direction may be provided adjacent to the boundary line 13b with
the usual land part 20, in which case the entire bottom surface 18
of the dimple is flat.
[0020] The depth of the non-circular dimple 12 at the deepest
position is preferably, for example, at least approximately 0.05
mm, and more preferably at least approximately 0.10 mm. Also, the
upper limit of the depth of the non-circular dimple 12 is
preferably approximately 0.45 mm and more preferably approximately
0.35 mm.
[0021] The size of the non-circular dimple 12, that is, the maximum
distance between two points on the outer edge 13 of the
non-circular dimple 12, is preferably at least approximately 0.5
mm, and more preferably at least approximately 1 mm. Also, the
upper limit of the size of the non-circular dimple 12 is preferably
approximately 8 mm, and more preferably approximately 7 mm.
[0022] Because if the spacing between the outer edges of a
plurality of non-circular dimples is too long, the land part 20
will become partially widened and could influence the aerodynamic
characteristics of the golf ball, the spacing is preferably no
greater than approximately 2.0 mm, and more preferably no greater
than approximately 1.8 mm. Also, the lower limit of the spacing
between the non-circular dimples 12, although not particularly
limited, is preferably approximately 0.05 mm, and more preferably
approximately 0.1 mm.
[0023] Although FIG. 1 shows the case in which the total number of
dimples is 332 and there is one land part 22 representing a symbol,
the present invention is not limited to this, and there may two or
more land parts representing symbols. In the case in which a golf
ball includes two or more land parts representing symbols, the
symbols can either be the same or different. Preferably, the number
of land parts representing symbols may be, but is not limited to,
at most approximately six.
[0024] Preferably, the land part 22 representing a symbol may be
arranged on the surface of the golf ball 1 such that a pole point
30 such as north or south pole of the golf ball falls within a
region of the land part 22 representing a symbol, as shown in FIG.
3, but the present invention is not limited to this. A pole point
of a golf ball usually is positioned at an end of a vent pin that
is disposed along the axis of a die used to mold the golf ball (not
shown). By using these arrangements, the burrs caused by the end of
the vent pin can be easily removed by grinding. Dimples, including
non-circular dimples, which form the land part 22 that represents a
symbol by its outer edge, are arranged in one dimple pattern 32,
with the other dimples being disposed in a plurality of dimple
pattern units 34 in rotational symmetry about the pole point 30 as
the center, so that even if the land part forms a symbol, it is
possible to maintain a ratio of surface area occupied by
dimples.
[0025] Although FIG. 3 shows the case of three-fold rotational
symmetry with a rotational symmetry angle of 120.degree., the
present invention is not limited to this, and may have, for
example, four-fold, five-fold, or six-fold rotational symmetry. In
the case of a golf ball mold that splits apart top and bottom, if
the vent pin is positioned at a pole point 30, the parting seam
between the top and the bottom parts of the mold is positioned at
the equator 36 of the golf ball 1. As an alternative to the
embodiment shown in FIG. 3, the land part representing a symbol may
be disposed on the surface of the golf ball so that the parting
line passes through the region of the land part that represents the
symbol.
[0026] The total number of dimples, including non-circular dimples,
formed on the surface of the golf ball, is preferably at least
approximately 150, more preferably at least approximately 200, even
more preferably at least 250, and still more preferably at least
approximately 300. Also, the upper limit on the total number of
dimples is preferably approximately 500, more preferably
approximately 400, and even more preferably approximately 360.
[0027] The proportion of surface area occupied by the dimples,
including non-circular dimples, is preferably at least
approximately 70%, and more preferably at least approximately 80%.
Also, although there is no particular restriction, from the
standpoint of providing a land part 22 to represent a symbol, the
upper limit of the proportion of the surface area occupied by the
dimples is preferably approximately 90%.
[0028] Although FIG. 1 shows the case in which one land part 22
that represents one symbol is formed by the outer edges of the
eight non-circular dimples 12a through 12h, the present invention
is not limited to this, and it is possible to form one land part
that represents one symbol by the outer edges of at least two
non-circular dimples, without greatly influencing the aerodynamic
characteristics of the golf ball. More preferably, at least three
non-circular dimples are used. The upper limit on the number of
non-circular dimples that form a land part that represents one
symbol is preferably approximately 15, and more preferably
approximately 12, although the present invention is not limited to
this.
[0029] Although FIG. 1 shows the case in which the land part 22
represents a logo as a symbol, the present invention is not limited
to this, and the symbol represented by the land part may include a
numeral, a letter, or a picture and the like, as well as a logo. By
using one or more symbols such numerals, letters, pictures and
logos, it is possible to represent a company, a product, a
trademark, a person or a mascot character. These may be related to
golf or to balls, or may not be directly related to golf or to
balls.
[0030] For example, as shown in FIG. 4, it is possible to form six
land parts 40 that represent the six letters N, E, W, I, N, and G.
The six land parts spell NEWING, a trademark of Bridgestone Sports
Co., LTD. The land part that represents the letter "N" is formed by
the outer edges of the four non-circular dimples 42a through 42d.
The land part that represents the letter "W" is formed by the outer
edges of the seven non-circular dimples 42d through 42j. The land
part that represents the letter "l" is formed by the outer edges of
the two non-circular dimples 42i and 42j.
[0031] Although FIGS. 1 and 4 show the cases in which the land
parts 22, 40 that represent symbols are all formed by the
non-circular dimples 12, 42, the present invention is not limited
to this, and whether a dimple has a circular or non-circular shape
when viewed from above is determined by the shape of the symbol,
which may also, of course, be formed by the outer edges of circular
dimples.
[0032] In the same manner as in the case of the usual circular
dimples, the non-circular dimples that form land parts representing
symbols by their outer edges can be formed in the process step of
forming the cover layer of the golf ball. Specifically, the cover
layer is formed by injection molding of the cover layer material
into a die. The die for the cover layer (not shown) has a cavity
wall surface for the purpose of forming the surface of the land
part and concave parts protruding from the cavity wall surface for
the purpose of forming dimples.
[0033] The die may be fabricated by using 3-dimensional CAD or CAM
and by using a method in which an overall surface shape is directly
and three-dimensionally formed in a reversing master die, or a
method in which a cavity part of the die is directly and
three-dimensionally machined.
[0034] Materials for the cover layer may be, but are not limited
to, an ionomer resin, a polyurethane-based thermoplastic elastomer,
or thermoplastic polyurethane. The golf ball may be of one-piece
structure or of a multiple-piece structure having two or more
pieces.
[0035] While a golf ball according to the present invention has
been described in connection with preferred embodiments, it is not
intended to limit the scope of the invention to the particular form
set forth, and on the contrary, it is intended to cover such
alternatives and modifications as may be included within the spirit
and scope of the invention as defined by the appended claims.
* * * * *