U.S. patent application number 10/225640 was filed with the patent office on 2004-02-26 for golf ball finishing method.
Invention is credited to Brum, William.
Application Number | 20040038627 10/225640 |
Document ID | / |
Family ID | 31887045 |
Filed Date | 2004-02-26 |
United States Patent
Application |
20040038627 |
Kind Code |
A1 |
Brum, William |
February 26, 2004 |
Golf ball finishing method
Abstract
A method of removing parting line flash from a molded golf ball
by use of low temperature cryogenic deflashing apparatus is
disclosed. The cryogenic deflashing apparatus incorporates a
rotating basket wherein the golf balls are placed and therein
agitate them such that each ball will be evenly exposed to a
recirculating blasting media. The low temperature environment
causes the very thin gauge (0.003") parting line flash to become
embrittled relative to the ball and is deflashed by the blasting
media, which comprises plastic pellitized shot.
Inventors: |
Brum, William; (Raynham,
MA) |
Correspondence
Address: |
D. Michael Burns
Acushnet Company
333 Bridge Street
Fairhaven
MA
02719
US
|
Family ID: |
31887045 |
Appl. No.: |
10/225640 |
Filed: |
August 22, 2002 |
Current U.S.
Class: |
451/32 ;
451/33 |
Current CPC
Class: |
B24B 31/02 20130101 |
Class at
Publication: |
451/32 ;
451/33 |
International
Class: |
B24B 001/00 |
Claims
I claim:
1. A method for removing parting line flash from golf balls, the
method comprising: loading a plurality of golf ball components with
flash into a rotating tumbler within a cryogenic chamber; agitating
the tumbler to expose the surfaces of the golf ball components;
lowering temperature in the chamber to less than about -100.degree.
F.; introducing plastic media into the chamber to remove the flash;
and removing the golf ball components from the chamber.
2. The method of claim 1, wherein the step of lowering the
temperature of the chamber is by the introduction of high-purity,
moisture-free liquid nitrogen into the chamber.
3. The method of claim 2, wherein the lowering of the temperature
in the chamber is to a temperature of between about -100.degree. F.
and about -220.degree. F.
4. The method of claim 1, wherein the plastic media are particles
with an average diameter less than about xxx inches.
5. The method of claim 1, wherein the golf ball components are
exposed for less than xxxx minutes.
6. A golf ball produced by the method of claim 1.
Description
FIELD OF THE INVENTION
[0001] The invention relates to an improved method for finishing
the surface of golf balls. More specifically, the improvement is
directed to the removal of parting line flash from molded golf
balls by a cryogenic deflashing apparatus.
BACKGROUND OF THE INVENTION
[0002] Conventional golf balls can be divided into two general
types or groups: solid balls and wound balls. The difference in
play characteristics resulting from these different types of
construction can be quite significant.
[0003] Balls having a solid construction are generally most popular
with the average recreational golfer because they provide a very
durable ball while also providing maximum distance. Solid balls are
generally made with a single solid core, usually made of
cross-linked rubber, which is encased by a cover material.
Typically the solid core is made of polybutadiene which is
chemically cross-linked with zinc diacrylic and/or similar
cross-linking agents and is covered by a tough, cut-proof blended
cover. The cover is generally a material such as SURLYN.RTM., which
is a trademark for an ionomer resin produced by DuPont. Wound balls
typically have either a solid rubber or liquid center core around
which many yards of stretched elastic are wound. Wound balls are
generally softer and provide more spin, which enables a skilled
golfer to have control over the ball's flight and final
position.
[0004] Regardless of the form of the ball, players generally seek a
golf ball that delivers the best combination as to maximum
distance, spin and durability. Golf ball manufacturers are
continually searching for new ways in which to provide golf balls
that deliver the maximum performance for golfers at all skill
levels.
[0005] The outer cover of either type golf ball are formed with
various materials that may be urethane elastomers, Balata, ionomers
or any other appropriate materials. The cover surfaces are formed
with dimples of various numbers, sizes and patterns, which improve
flight distance, control and stability. The outer surface of the
ball covers usually have the manufacturers indicia disposed thereon
as well as an application of a paint or clear coat for the purposes
not only of good appearance but also of improving fight distance
and protecting of the indicia imprinted thereon.
[0006] The process of molding a cover over a golf ball subassembly
usually produces a golf ball having a parting flash line, i.e. the
area adjacent the interfacing mold surfaces. Such residual flash is
not only aesthetically objectionable, but additionally functionally
objectionable, and therefore must be removed, i.e. deflashed, from
the article prior to use of the same. It has been necessary to
perform a buffing or finishing step to remove this flash. The prior
art method of removing the flash is to employ mechanical cutting
blades and sandpaper. This method requires a high level of
intervention due to belt and blade wear and also requires precise
orientation of the subassembly on the buffing equipment. A method
of finishing golf balls in a bulk process without the need for mold
orientation of balls is highly desired.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to an improved method of
removing parting line flash from a golf ball component following
the molding of a layer on a ball subassembly. The process is
preferably used for deflashing golf balls after the cover layer has
been molded onto the ball subassembly. The process is most
preferably used for non-planar parting lines. The invention allows
for golf ball coponents to be bulk loaded into a cryogenic chamber
where the temperature of the ball is reduced by liquid nitrogen.
Operating temperatures are typically below -100.degree. F. Because
of the thin gauge of the parting line flash relative to the layer
thickness, (the gauge of the flash generally only about 0.003
inches) the flash becomes embrittled in comparison to the layer.
The chamber contains a rotating tumbler to agitate and expose the
golf ball components during the flash removal cycle. As the chilled
product rotates a plastic media is delivered at high velocity which
further enhances the flash removal process.
[0008] The present invention provides for the removal of flash
lines in a batch method therein eliminating the need for orienting
each golf ball prior to deflashing, and also eliminating the need
for orientation tabs.
[0009] The present invention reduces the maintenance and downtime
due to changing and replacing sanding belts and cutting blades.
[0010] Batch buffing allows for bulk loading and unloading thereby
simplifying the material handling process.
[0011] The present invention allows for easier finishing of varying
symmetry of parting lines and dimple patterns.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 describes a process flow chart for the present
invention's method for golf ball finishing.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] The present invention applies to all thermoplastic or
thermoset layers on golf balls that require finishing or removal of
flashing that accrues from the molding of the layer on a golf ball
subassembly.
[0014] In the manufacture of golf balls, flash lines are routinely
removed by mechanical buffing procedures in which mechanical
cutting blades and sand paper are utilized as a buffing medium. The
orientation of the ball is of primary importance for the buffing
step. Orientation tabs are typically molded into the ball to
accommodate this requirement. The replacement of belts and blades
adds to the significant intervention required for these procedures.
With the advent of future golf balls having irregular flash lines
(non-planar), there is a strong need for a method for removing the
flash without having to orient the balls for a buffing process. The
present invention utilizes a cryogenic process that does not
require orientation of the golf balls in order for the flash to be
removed, and also eliminates the need for sandpaper and cutting
blades.
[0015] FIG. 1 displays a flow chart wherein golf balls are moved
from compression mold racks by automatic transport to a bulk
die-out. From there they are transported to a cryogenic apparatus
and placed into a stainless steel parts basket of the apparatus.
The parts basket rotates in a blast chamber evenly exposing all
golf balls to the blast media. The chamber is insulated with rigid
polyurethane foam to ensure stable temperatures. Liquid nitrogen
lowers the interior temperature, freezing the flashing to make it
brittle. Use of high purity, moisture-free nitrogen eliminates the
need for a dryer and prevents part contamination due to moisture. A
high speed impeller introduces a blasting media typically
comprising pellitized shot. Operating temperatures are typically
below -100.degree. F., preferably in a range between about
-100.degree. F. to about -220.degree. F., and more preferably about
-190.degree. F. The process time is about ten minutes.
[0016] The parting line flash is of a rather thin gauge (0.003
inches) relative to the thickness of the molded cover, and
therefore only the parting line flash becomes embrittled in the low
blasting media stream. By controlling the exposure duration of the
molded golf balls within the cryogenic environment, as well as the
velocity and dispersion of the deflashing media against them, it
has been found that satisfactory golf ball deflashing may be
accomplished, typically at a substantial reduction over sanding
deflashing operations. After the flashing has been removed the
balls are bulk unloaded for further processing. Acceptable
cryogenic equipment includes machines such as those manufactured by
Cryogenic Deflashing Systems, Inc. of Santa Ana, Calif., and based
upon the teachings of U.S. Pat. No. 4,979,338, which is
incorporated by reference herein in its entirety.
* * * * *