U.S. patent application number 10/190876 was filed with the patent office on 2002-11-21 for non-circular vent pin for golf ball injection mold and golf ball formed therefrom.
This patent application is currently assigned to Spalding Sports Worldwide, Inc.. Invention is credited to Kennedy, Thomas J., Shannon, Kevin J., Tavares, Gary.
Application Number | 20020173385 10/190876 |
Document ID | / |
Family ID | 24780835 |
Filed Date | 2002-11-21 |
United States Patent
Application |
20020173385 |
Kind Code |
A1 |
Shannon, Kevin J. ; et
al. |
November 21, 2002 |
Non-circular vent pin for golf ball injection mold and golf ball
formed therefrom
Abstract
An improved vent pin for a golf ball injection mold is
characterized by a non-circular configuration so that a
non-circular dimple can be formed at one or both poles of the golf
ball. The vent pin is coaxially arranged within a passage in the
injection mold which is aligned with a radius of the ball which
passes through one of the poles thereof. The pin is operable
between a normal position where the end of the pin closes the
passage lower end and a retracted position where the pin end is
withdrawn into the passage so that air from a cavity of the mold
where the cover layer of the ball is formed can be vented during
delivery of thermoplastic material to the cavity to form the golf
ball cover.
Inventors: |
Shannon, Kevin J.;
(Longmeadow, MA) ; Kennedy, Thomas J.; (Wilbraham,
MA) ; Tavares, Gary; (Banks, OR) |
Correspondence
Address: |
MICHELLE BUGBEE, ASSOCIATE PATENT COUNSEL
SPALDING SPORTS WORLDWIDE INC
425 MEADOW STREET
PO BOX 901
CHICOPEE
MA
01021-0901
US
|
Assignee: |
Spalding Sports Worldwide,
Inc.
Chicopee
MA
|
Family ID: |
24780835 |
Appl. No.: |
10/190876 |
Filed: |
July 8, 2002 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10190876 |
Jul 8, 2002 |
|
|
|
09692502 |
Oct 19, 2000 |
|
|
|
6422850 |
|
|
|
|
Current U.S.
Class: |
473/378 |
Current CPC
Class: |
Y10S 425/812 20130101;
B29C 45/34 20130101; A63B 37/0023 20130101; B29C 45/14073 20130101;
A63B 45/00 20130101; A63B 37/0007 20130101; A63B 37/0004 20130101;
A63B 37/00065 20200801; B29L 2031/545 20130101 |
Class at
Publication: |
473/378 |
International
Class: |
A63B 037/14 |
Claims
What is claimed is:
1. A vent mechanism for a golf ball injection mold containing a
spherical cavity in which a cover layer is applied to a golf ball
core to form a dimpled golf ball, comprising a solid pin coaxially
arranged within a passage in the injection mold, the passage
extending from the cavity along a radius of the golf ball through
one of the poles thereof and having a non-circular end
communicating with the cavity, said pin being operable between a
normal position wherein an end of said pin closes said passage
lower end and a retracted position wherein said pin end is arranged
within said passage and spaced from the cavity to allow air to
enter said passage from the injection mold cavity, said pin end
having a non-circular cross-sectional configuration corresponding
with that of said passage end, whereby a dimple formed by said pin
at the pole of the golf ball has a non-circular configuration.
2. A vent mechanism for a golf ball injection mold as defined in
claim 1, wherein said pin end has a convex configuration.
3. A vent mechanism for a golf ball injection mold as defined in
claim 2, wherein said pin is further operable between an extended
position wherein said pin end is arranged within the cavity to
eject a golf ball therefrom.
4. A vent mechanism for a golf ball injection mold as defined in
claim 3, and further comprising means for displacing said pin
between said extended, normal and retracted positions.
5. A vent mechanism for a golf ball injection mold as defined in
claim 4, wherein said pin end has an oblong cross-sectional
configuration.
6. A vent mechanism for a golf ball injection mold as defined in
claim 4, wherein said pin end has an elliptical cross-sectional
configuration.
7. An injection mold for applying a cover layer to golf balls,
comprising (a) upper and lower support plates each containing at
least one hemispherical cavity, said upper and lower hemispherical
cavities being adapted to mate to define at least one spherical
cavity in which a core of a golf ball is supported when said plates
are brought together; (b) means for supplying thermoplastic
material to said cavities to form a cover on the golf ball core;
and (c) means for venting air from said cavities as thermoplastic
material is supplied thereto, each of said venting means comprising
a pin arranged within a vent passage of said plates communicating
with said spherical cavities, respectively, said pin having an axis
extending along a radius of said cavity through a pole of the golf
ball being formed therein, said pin being operable between a normal
position wherein an end of said pin closes an end of said passage
adjacent to said cavity and a retracted position wherein said pin
end is arranged within said passage and spaced from said cavity to
allow air to enter said passage from the cavity, said pin end
having a noncircular cross-sectional configuration, whereby a
dimple formed by said pin at the pole of the golf ball has a
non-circular configuration.
8. An injection mold as defined in claim 7, wherein said pin end
has a convex configuration.
9. An injection mold as defined in claim 8, wherein said pin is
further operable between an extended position wherein said pin end
is arranged in said cavity to eject a golf ball therefrom.
10. An injection mold as defined in claim 9, and further comprising
means for displacing said pin between said extended, normal and
retracted positions.
11. An injection mold as defined in claim 10, wherein said pin end
has an oblong cross-sectional configuration.
12. An injection mold as defined in claim 10, wherein said pin end
has an elliptical cross-sectional configuration.
13. A dimple pattern for a golf ball having a cover layer formed by
an injection mold, the cover layer comprising two hemispherical
surfaces formed by hemispherical cavities of the injection mold,
said hemispherical surfaces being joined at an equator of the golf
ball, each of said hemispherical surfaces being identical and
including a plurality of first non-circular dimples formed by
projections on surfaces of the hemispherical cavities and a second
non-circular dimple formed at the pole of the golf ball, the pole
dimple being formed by a non-circular vent pin of the mold.
14. A dimple pattern for a golf ball as defined in claim 13,
wherein none of said dimples overlap.
15. A dimple pattern as defined in claim 14, wherein said first and
second dimples have the same configuration.
16. A dimple pattern as defined in claim 15, wherein said first and
second dimples have an elongated configuration.
17. A dimple pattern as defined in claim 15, wherein said first and
second dimples have an elliptical configuration.
18. A dimple pattern as defined in claim 14, wherein the dimples of
said first group of dimples have a different dimension.
19. A dimple pattern as defined in claim 18, wherein the dimples of
said first group of dimples have at least two different
configurations.
Description
BACKGROUND OF THE INVENTION
[0001] In the golf ball manufacturing process, it is common
practice to form the cover of the ball using injection molding. A
mold comprising a pair of parallel plates containing opposed
hemispherical cavities is used to form a spherical cavity within
which a golf ball core is suspended by retractable pins.
Thermoplastic material is supplied to the cavity along a parting
line defined where the hemispherical cavities terminated at the
surface of the molding plates. The thermoplastic material surrounds
the core to form the cover layer of the ball. Vent pins in the
bottom of the hemispherical cavities, i.e. at the poles of the golf
ball, allow air to exit the cavity as thermoplastic material is
applied thereto. Following evacuation, the vent pins plug the vent
openings and form pole dimples on the ball.
BRIEF DESCRIPTION OF THE PRIOR ART
[0002] Injection molds for forming golf balls are well-known in the
patented prior art. The Lavallee et al U.S. Pat. No. 5,122,046, for
example, discloses a retractable pin golf ball injection mold
wherein the clearance at the parting line is reduced to prevent a
flash line from being formed at the equator of the ball when the
mold plates are separated to eject a finished ball therefrom. The
Lavallee et al U.S. Pat. No. 5,827,548 improves on the earlier
Lavallee et al patent by providing a retractable pin golf ball
injection mold wherein a cooling circuit is provided in the mold
plates to decrease the setting time of the thermoplastic material
and a two-stage ejector mechanism is provided to independently
eject excess thermoplastic material from the runners used to supply
the material to the cavities and to eject the finished golf ball
from the mold cavity.
[0003] Most golf ball injection molds of the prior art include a
vent pin to allow air to be evacuated from the cavities as
thermoplastic material is being supplied thereto to allow even
distribution of the thermoplastic material around the golf ball
centers. Because the vent pins have a circular cross-sectional
configuration, the pole dimples on the ball are always circular. It
has not been possible, therefore, with prior golf ball injection
molds to form a dimpled golf ball without having circular dimples
at the poles. However, owing to the realization of the influence of
dimple configurations on ball flight, many golf balls today are
formed with noncircular dimples. It is thus desirable to be able to
form a golf ball with an injection molded cover layer wherein all
of the dimples, including those at the poles of the ball, have a
non-circular configuration.
SUMMARY OF THE INVENTION
[0004] Accordingly, it is a primary object of the present invention
to provide a vent mechanism for a golf ball injection mold
containing a spherical cavity in which a cover layer is applied to
a golf ball core to form a dimpled golf ball. The mold contains a
vent passage communicating with the spherical cavity and a vent pin
is arranged within the passage. The passage extends from the cavity
along a radius of the golf ball through one of the poles thereof.
The passage has a non-circular end communicating with the cavity,
and the pin is operable between a normal position wherein an end of
the pin closes the passage lower end and a retracted position
wherein the pin end is arranged within the passage and spaced from
the cavity to allow air to enter the passage from the cavity as
thermoplastic material is supplied to the cavity to form the cover
layer on the ball. The pin end has a noncircular cross-sectional
configuration corresponding with that of the passage end so that a
dimple formed by the pin at the pole of the golf ball has a
non-circular configuration.
[0005] According to a further object of the invention, the pin is
also operable between an extended position wherein the pin end is
arranged within the cavity to eject the golf ball therefrom.
[0006] Another object of the invention is form a golf ball having a
cover layer containing all non-circular dimples. The cover layer
includes two hemispherical surfaces formed by hemispherical
cavities of an injection mold. The hemispherical surfaces are
identical and are joined at the equator of the golf ball. Each
hemispherical surface includes a plurality of first non-circular
dimples formed by projections on the surfaces of the hemispherical
cavities and a second non-circular dimpled formed at the pole of
the golf ball, the pole dimple being formed by a noncircular vent
pin of the mold. Preferably, none of the dimples overlap. They may
have the same or different configurations and sizes.
BRIEF DESCRIPTION OF THE FIGURES
[0007] Other objects and advantages of the invention will become
apparent from a study of the following specification when viewed in
the light of the accompanying drawings, in which:
[0008] FIG. 1 is a sectional view of a golf ball injection mold
apparatus including a non-circular vent pin according to the
invention;
[0009] FIGS. 2A-2C are partial schematic views showing the
displacement of the vent of the invention between retracted,
normal, and extended positions, respectively;
[0010] FIG. 3 is a bottom view of the vent pin showing an oblong
configuration of the pin end;
[0011] FIG. 4 is a bottom view of the vent pin showing an
elliptical configuration of the pin end; and
[0012] FIG. 5 is a plan view of a golf ball according to the
invention with noncircular dimples on the ball surface, including
at the poles of the ball.
DETAILED DESCRIPTION
[0013] As shown in FIG. 1, a golf ball injection mold according to
the invention includes upper 2 and lower 4 plates which can be
displace relative to one another in a conventional manner between
the contiguous position shown and a spaced position. The lower
plate 4 includes at least one hemispherical cavity 6 in the upper
surface thereof, while the upper plate 2 includes a corresponding
hemispherical cavity 8 in the lower surface thereof. A parting line
is defined where each hemispherical cavity terminates with the
corresponding surface. When the plates are brought together in
contiguous relation as shown, the respective upper and lower
hemispherical cavities cooperate to define a spherical cavity for
forming a golf ball.
[0014] Each hemispherical cavity includes a patterned surface 10
which will define a dimple pattern in the outer surface of the golf
ball. The upper hemispherical cavity 8 also includes a plurality of
retractable core pins 12 and the lower hemispherical cavity 6
includes a plurality of retractable core pins 14. The pins have
axes perpendicular to the parting line of the respective plates and
are extensible into the spherical cavity to support a golf ball
core during the injection molding process. Extension and retraction
of the core pins is accomplished through displacement of a
conventional piston mechanism (not shown).
[0015] In order to supply thermoplastic material to the cavity, a
runner is provided in the upper and lower plates. The runner 16
comprises a network of feeder lines in the surfaces of the upper
and lower plates which define flow channels when the plates are in
contiguous relation. The runner is connected with each cavity via
gates 18 at the parting line. Accordingly, thermoplastic material
is supplied to the cavity at various locations around the parting
line for even distribution about the core of the golf ball. Vent
pins 20 are provided at the bottom of the upper and lower
hemispherical cavities to evacuate air from the spherical cavity as
thermoplastic material is supplied thereto. If desired, a vacuum 22
may be connected with each vent pin 20 to assist in drawing air
from the cavity so that the thermoplastic material may more evenly
be distributed around the ball core for even coverage thereof. To
decrease the time required for cooling and setting of the
thermoplastic material on the golf ball core, a coolant such as
water is supplied adjacent to each cavity via channels 24, 26 in
the upper and lower plates, respectively.
[0016] Each vent pin is arranged in a passage in the mold plates,
the passage and the axis of the pins being aligned with a radius of
the golf ball that passes through the poles of the ball. All of the
vent pins have a similar structure, so only one vent pin will be
described in greater detail in connection with FIGS. 2A-2C. The
interior of the passage 28 has two widths, W1 and W2. The greater
width W1 is spaced from the spherical cavity 30 and the narrower
width W2 is adjacent the spherical cavity. The pin also has two
widths W3 and W4. The width W3 is remote from the free end of the
pin and is less than the width W4 which is at the end of the pin.
The width W4 corresponds generally with the width W2 so that the
pin end can pass through or close the end of the passage.
[0017] More particularly, the pin is displaced relative to the
passage 28 by a displacement mechanism 32 between a retracted
position shown in FIG. 2A where the pin is within the passage and
the pin end is spaced from the spherical cavity, a normal position
shown in FIG. 2B were the pin end closes the end of the passage,
and an extended position shown in FIG. 2C where the pin end is
arranged beyond the passage and in the spherical cavity. With the
pin in the retracted position shown in FIG. 2A, air from the cavity
30 is vented into the passage during delivery of thermoplastic
material to the cavity to form the golf ball cover layer. When the
cavity has been filled, the displacement mechanism 32 moves the pin
to its normal position shown in FIG. 2B to close the opening to the
passage. Following curing of the cover layer, the displacement
mechanism 32 moves the pin to the extended position to eject a golf
ball from the cavity.
[0018] Preferably, when the pin is in the normal position of FIG.
2B, the pin end protrudes slightly into the spherical cavity to
form a dimple on the pole of the golf ball. The pin end bottom
surface thus is preferably convex. Unlike conventional vent pins,
however, the pin of the present invention is non-circular, as is
the opening to the passage from the spherical cavity. Accordingly,
non-circular dimples are formed at the poles of the golf ball.
Examples of non-circular pins are shown in FIGS. 3 and 4 wherein
oblong and elliptical vent pins are shown, respectively. Of course,
any desired non-circular shape may be provided for the pin,
including star, tear-drop, and geometrical configurations to form
correspondingly shaped dimples at the poles.
[0019] The resulting golf ball is shown in FIG. 5. The ball has two
hemispherical surfaces 34, 36 formed by the hemispherical cavities
6, 8 in the mold plates. The surfaces meet at the equator E of the
ball where the parting line is formed. The pole dimples P formed by
the non-circular vent pins are also non-circular. In the example of
FIG. 5, the pole dimple is elliptical. Non-circular dimples 38 are
formed in the ball surface by the patterns 10 in the hemispherical
cavities. If desired, all of the dimples on the ball surface may
have the same configuration and size. Alternatively, different
sized dimples may be provided. Moreover, a combination of
differently configured dimples may be provided on the ball surface.
In FIG. 5, the dimples 38a are elliptical and the dimples 38b are
oblong. The dimples can be arranged in a repeatable pattern in each
hemisphere, so long as both hemispheres have the same pattern and
configurations of dimples.
[0020] The golf ball according to the invention having all
non-circular dimples, including the pole dimples, has different
flight characteristics than traditional golf balls having circular
dimples. These characteristics reduce hooking or slicing of the
ball in flight and also increase the distance that a ball will
carry.
[0021] While the preferred forms and embodiments of the invention
have been illustrated and described, it will be apparent to those
of ordinary skill in the art that various changes and modifications
may be made without deviating from the inventive concepts set forth
above.
* * * * *