U.S. patent application number 10/167308 was filed with the patent office on 2003-12-11 for sports balls.
Invention is credited to Chan, Chong Veng.
Application Number | 20030228946 10/167308 |
Document ID | / |
Family ID | 29710862 |
Filed Date | 2003-12-11 |
United States Patent
Application |
20030228946 |
Kind Code |
A1 |
Chan, Chong Veng |
December 11, 2003 |
Sports balls
Abstract
Sports balls are provided having a reinforced carcass with a
resilient layer. The sports balls exhibit good durability and
softness.
Inventors: |
Chan, Chong Veng; (Hong
Kong, HK) |
Correspondence
Address: |
FISH & RICHARDSON PC
225 FRANKLIN ST
BOSTON
MA
02110
US
|
Family ID: |
29710862 |
Appl. No.: |
10/167308 |
Filed: |
June 11, 2002 |
Current U.S.
Class: |
473/604 ;
473/605 |
Current CPC
Class: |
A63B 41/00 20130101;
A63B 2208/12 20130101; A63B 45/00 20130101; A63B 2243/0025
20130101; A63B 41/02 20130101 |
Class at
Publication: |
473/604 ;
473/605 |
International
Class: |
A63B 041/00 |
Claims
What is claimed is:
1. A sports ball comprising: a ball cover, and, disposed within the
ball cover, a reinforced inflatable carcass comprising (a) an
inflatable bladder of resilient material; (b) a web layer of thread
disposed about an outer surface of said bladder; and (c) an outer
layer of resilient material adhered upon said web layer.
2. The sports ball of claim 1 wherein a major segment of an outer
surface of said carcass is free of adhesion to an opposed inner
surface of the ball cover.
3. The sports ball of claim 2 wherein at least 80% of the outer
surface of the carcass is free of adhesion to the opposed inner
surface of the ball cover.
4. The sports ball of claim 1 wherein the outer layer of said
carcass comprises an elastomeric material.
5. The sports ball of claim 1 wherein the outer layer of said
carcass comprises a resilient foam.
6. The sports ball of claim 1 wherein the web layer comprises a
reinforcing material.
7. The sports ball of claim 1 wherein the ball cover comprises a
material selected from the group consisting of leather and
synthetic leather.
8. The sports ball of claim 1 wherein the ball cover has a
thickness of less than about 3.5 mm.
9. The sports ball of claim 1 wherein the ball cover consists of a
layer of synthetic leather.
10. The sports ball of claim 1 wherein the ball cover consists of
leather having a thickness of less than about 1.5 mm.
11. The sports ball of claim 1 wherein the resilient layer has a
thickness of from about 0.5 to 3.0 mm.
12. The sports ball of claim 1 wherein the resilient layer
comprises a material selected from the group consisting of rubber,
foamed rubber and EVA (ethylene vinyl acetate) foam.
13. The sports ball of claim 1 wherein the web layer comprises a
thread selected from the group consisting of nylon, polyester and
cotton threads.
14. A method of forming a sports ball cover comprising the steps
of: (a) inflating a bladder to a predetermined circumference; (b)
adhering a reinforcing thread about an outer surface of the
inflated bladder, thereby to form a web layer on the outer surface;
and (c) applying a resilient layer to the web layer to form a
carcass.
15. The method of claim 14, for forming a sports ball comprising
the further steps of: (d) inserting the carcass into a ball cover
having an opening to receive the carcass; and (e) closing the
opening in the ball cover to form a finished sports ball.
16. The method of claim 14 wherein the inflating step comprises
inflating the bladder to a circumference of about 67.5 to 68.0
cms.
17. The method of claim 15 further comprising deflating the carcass
between steps (c) and (d).
18. The method of claim 14 further comprising adhering the
resilient layer to the web layer.
19. The method of claim 15 further comprising, between steps (c)
and (d), curing the carcass in a heated mold.
20. The method of claim 14 wherein the resilient layer comprises a
material selected from the group consisting of elastomers, natural
rubber, and foams.
21. The method of claim 14 further comprising bonding the bladder,
web layer and resilient layer securely together.
22. The method of claim 14 further comprising providing the ball
cover by cutting a ball cover material into a predetermined number
of panels in predetermined shape and stitching the panels together
edge-to-edge, leaving an opening for insertion of the carcass.
23. The method of claim 22 wherein the stitching is performed by
machine.
24. The method of claim 22 wherein the ball cover is stitched
together inside out, and the method further comprises turning the
ball cover right side out prior to inserting the carcass.
25. The method of claim 20 wherein the material is selected from
the group consisting of rubber, foamed rubber and EVA (ethylene
vinyl acetate) foam.
26. The method of claim 14 wherein the ball cover includes a lining
layer.
27. The method of claim 14 wherein the thread comprises a material
selected from the group consisting of nylon, polyester and cotton.
Description
TECHNICAL FIELD
[0001] This invention relates to sports balls, and more
particularly to soccer balls and volleyballs.
BACKGROUND
[0002] As shown in FIGS. 1 and 2, a conventional sports ball 10,
e.g., a soccer ball or volleyball, generally includes a ball cover
12 made up of a plurality of panels 14, and an inflatable rubber
bladder 16 within the cover. The ball cover is typically made of
leather, or a synthetic leather such as polyurethane (PU) or
polyvinyl chloride (PVC). One or more lining layers 18 may be
laminated to the inner surface of the synthetic leather to form the
ball cover. For example, as shown in FIG. 2, the ball cover may
consist of a laminate of an outer coating layer 20 of synthetic
material, an intermediate foam layer 22, an inner lining layer 24
to strengthen and support the foam layer, and an additional inner
lining layer 26.
[0003] The leather or synthetic leather is cut into a plurality of
panels of predetermined shape. A soccer ball combines pentagonal
and hexagonal panel shapes. Typically, the ball cover of a soccer
ball is made of twelve pentagonal panels and twenty hexagonal
panels, whereas the ball cover of a volleyball is made of eighteen
generally rectangular panels. In either case, the panels are either
machine or hand stitched together edge-to-edge, by a sewing thread
28 (FIG. 2) to form a spherical cover. The stitched cover is then
inverted, and the inflatable bladder is placed inside the ball
cover (through an open seam) with its valve stem 30 extending
outside of the ball cover for inflation. The seam is then closed.
When air is pumped into the bladder through the valve stem, the air
inflates the bladder to support the ball cover and retain its
roundness. The bounce of the ball is a function of the air pressure
in the bladder; generally, the more air, the higher the bounce.
[0004] In some ball constructions, the bladder is reinforced by
winding a thread around the inflated bladder prior to inserting the
bladder into the ball cover. This construction provides a finished
ball that better maintains its spherical shape during use, with
increased durability. However, a ball with a wound bladder tends to
be less soft, with less bounce, e.g., as compared to a ball with a
bladder free of thread windings, at normal pressure.
[0005] Generally, a sports ball having a bladder without thread
winding has relatively greater bounce and softness. However, where
the bladder is without thread winding, the rigidity and durability
of the ball depend almost entirely on the structure of the ball
cover, as the unwound bladder contributes little durability and
stability to the ball. Thus in balls constructed without a wound
bladder, the ball cover must be tough enough to withstand all
anticipated impact forces.
[0006] In order to provide adequate stress resistance, the ball
cover is generally formed of panels that are reinforced by at least
two or more layers of lining material, as discussed above. However,
these additional lining layers contribute significantly to the
material and labor cost of the ball. The increased stiffness and
thickness of the panels, due to the presence of these lining
layers, may also make machine stitching of the cover panels
difficult in some cases.
[0007] In a ball constructed of a bladder reinforced by thread
windings, one or more lining layers may be eliminated, but, as
noted above, with resulting reduction in softness and bounce.
SUMMARY
[0008] An inflatable sports ball having a cover formed of multiple
panels contains an inflatable carcass formed of a bladder with
thread windings covered by an outer layer of resilient material.
This sports ball construction provides a combination of relatively
improved softness and bounce over traditional sports balls with a
bladder wound with threads and relatively improved durability over
traditional sports balls with a bladder free of thread windings. In
selected embodiments of the sports ball of the invention, use of
the inflatable carcass may permit elimination of one or more layers
of lining in the ball cover, with resultant reduction of weight and
labor costs, while maintaining acceptable standards of
performance.
[0009] The use of such a carcass provides a ball that maintains its
shape well during play. Because the carcass has good strength and
exhibits good shape retention and impact resisting ability, in many
applications it is not necessary to line the ball cover, reducing
the material and manufacturing costs of the sports ball. However,
if a substantially perfect spherical shape, and/or very high impact
resistance are required, one or more lining layers may be provided
to further enhance the properties of the sports ball.
[0010] Because the sports balls have good softness, the balls
provide good comfort during play, e.g., by reducing the discomfort
associated with heading in soccer games and spiking in volleyball.
This feature makes the balls particularly suitable for use by
children and less experienced players.
[0011] The balls also exhibit good roundness and ability to retain
an official size even when over-inflated, e.g., to 15 to 20% more
than standard pressure.
[0012] In one aspect, the invention features a sports ball
including a ball cover, and, disposed within the ball cover, a
reinforced inflatable carcass. The carcass includes (a) an
inflatable bladder of resilient material; (b) a web layer of thread
disposed about an outer surface of said bladder; and (c) an outer
layer of resilient material adhered upon said web layer.
[0013] Some implementations of this aspect of the invention include
one or more of the following features. A major segment of an outer
surface of said carcass is free of adhesion to an opposed inner
surface of the ball cover, e.g., at least 80% of the outer surface
of the carcass is free of adhesion to the opposed inner surface of
the ball cover. The outer layer of the carcass includes an
elastomeric material. The outer layer of the carcass includes a
resilient foam. The web layer includes a reinforcing material. The
ball cover includes a material selected from the group consisting
of leather and synthetic leather. The ball cover has a thickness of
less than about 3.5 mm. The ball cover consists of a layer of
synthetic leather. Alternatively, the ball cover consists of
leather having a thickness of less than about 2.0 mm. The resilient
layer has a thickness of from about 0.5 to 3.0 mm. The thickness of
the cover and the resilient layer are adjusted to meet different
bounce and softness requirements. The resilient layer comprises a
material selected from the group consisting of rubber, foamed
rubber and EVA (ethylene vinyl acetate) foam. The web layer
comprises a thread selected from the group consisting of nylon,
polyester and cotton threads.
[0014] The invention also features methods of making the sports
balls described above. In preferred implementations, the sports
balls are machine stitched, and thus are suitable for mass
production.
[0015] For example, in one aspect, the invention features a method
of forming a sports ball cover including (a) inflating a bladder to
a predetermined circumference; (b) adhering a reinforcing thread
about an outer surface of the inflated bladder, thereby to form a
web layer on the outer surface; and (c) applying a resilient layer
to the web layer to form a carcass.
[0016] Some implementations of this aspect of the invention include
one or more of the following features. The method further includes
(d) inserting the carcass into a ball cover having an opening to
receive the carcass; and (e) closing the opening in the ball cover
to form a finished sports ball. The inflating step includes
inflating the bladder to a circumference of about 67.5 to 68.0 cm
for an official size 5 soccer ball. The method further includes
deflating the carcass between steps (c) and (d). The method further
includes adhering the resilient layer to the web layer. The method
further includes, between steps (c) and (d), curing the carcass in
a heated mold. The resilient layer comprises a material selected
from the group consisting of elastomers, natural rubber, and foams.
The method further includes bonding the bladder, web layer and
resilient layer securely together. The method further includes
providing the ball cover by cutting a ball cover material into a
predetermined number of panels in predetermined shape and stitching
the panels together edge-to-edge, leaving an opening for insertion
of the carcass. The stitching is performed by machine. The ball
cover is stitched together inside out, and the method further
comprises turning the ball cover right side out prior to inserting
the carcass. The material is selected from the group consisting of
rubber, foamed rubber and EVA (ethylene vinyl acetate) foam. The
ball cover includes a lining layer. The thread includes a material
selected from the group consisting of nylon, polyester and
cotton.
[0017] Other features and advantages of the invention will be
apparent from the description and drawings, and from the
claims.
DESCRIPTION OF DRAWINGS
[0018] FIG. 1 is a perspective view in partial cross-section of a
conventional prior art sports ball.
[0019] FIG. 2 is an enlarged cross-sectional view of a portion of
the prior art sports ball shown in FIG. 1.
[0020] FIG. 3 is a perspective view, partial cross-section, of a
sports ball according to one embodiment of the invention. FIG. 3A
is an enlarged cross-sectional view of a portion of the soccer ball
of FIG. 3.
[0021] FIG. 4 is a perspective view of the strengthened bladder of
the sports ball of FIG. 3. FIG. 4A is a perspective view of the
strengthened bladder with a resilient layer partially applied to
its surface.
[0022] FIG. 5 is an enlarged cross-sectional view of a portion of a
sports ball according to an alternate embodiment of the
invention.
[0023] FIGS. 6-6I illustrate steps in a manufacturing method
according to one embodiment of the invention.
DETAILED DESCRIPTION
[0024] A soccer ball 40 of the invention is shown in FIGS. 3 and
3A. Soccer ball 40 includes a ball cover 12 and a carcass 42
disposed within the ball cover 12. The ball cover 12 is made of
leather or synthetic leather such as polyurethane (PU) or polyvinyl
chloride (PVC). As discussed above with respect to prior art soccer
balls, the leather or synthetic leather is provided in a plurality
of panels 14 of hexagonal and pentagonal shape, sewn edge-to-edge
with sewing thread 28.
[0025] The ball cover may have any desired structure. For example,
a suitable ball cover includes the layers described above with
reference to FIG. 2, i.e., an outer coating layer 20, an
intermediate foam layer 22, an inner lining layer 24 to strengthen
and support the foam layer, and an inner additional lining layer
26. However, because the carcass has good strength, as will be
discussed below, one or both of the lining layers may be
eliminated, if desired. Generally, the outer coating layer 20,
intermediate foam layer 22 and inner lining layer 24 are integrally
formed by foaming a polymer, e.g., polyurethane or PVC, in a manner
so that a sheet-form product is produced having a smooth skin (the
outer coating layer) on one surface. For a relatively low cost ball
that is easy to manufacture, it is generally preferred that the
ball cover material include only the outer coating layer,
intermediate foam layer and inner lining layer. The selection of
suitable ball cover materials will be discussed in further detail
below.
[0026] As shown in FIG. 3A, the carcass includes an inflatable
bladder 44, for example a rubber bladder, having a valve stem 30
(FIG. 3), a web layer 46, attached to an outer surface of the
bladder, and a resilient layer 48, bonded to the web layer. In the
embodiment shown in FIG. 3A, the resilient layer is an elastomeric
material. Other resilient materials can be used, as will be
discussed below.
[0027] The web layer 46 covers substantially the entire surface of
the bladder 44. The web layer includes reinforcing thread 43 (FIG.
6A). Generally, reinforcing thread 43 is provided in the form of a
plurality of threads, although a single continuous thread may be
used if desired. Suitable thread materials include, for example,
nylon, polyester and cotton thread, and threads containing blends
of these materials. As will be discussed below, to form the web
layer, the thread is first coated with adhesive, e.g., glue or
latex, and then wound evenly around and around the outer surface of
the bladder, so that the thread overlaps to form a spider-web like
structure. The bladder is inflated for the winding process, e.g.,
to a circumference of about 67.5 to 68 cm for an official size 5
soccer ball (this is less than the inflation circumference/pressure
used for play, e.g., 68.5 to 69.5 cm and 8.5 to 11.5 psi for the
same size ball). The web layer strengthens the bladder, which is
thin, e.g., about 0.3 to 1.5 mm thick, and thus is relatively weak.
Typically, about 50 to 100 grams of thread is used to make a size 5
soccer ball. Suitable threads generally have a thickness of about
0.25 to 0.8 mm and a strength of from about 50 to 150 N.
[0028] Suitable materials for the resilient layer include rubber,
other elastomers such as thermoplastic elastomers, and foams, e.g.,
foamed rubber and EVA (ethylene vinyl acetate) foams. A ball having
a bladder covered with the resilient foam layer is shown in FIG. 5.
The resilient layer is laminated to the surface of the web layer,
e.g., in the form of panels 49 as shown in FIG. 4A, and the
resulting carcass 42 may then be cured in a mold, if desired, as
will be discussed below. The resilient layer is generally about 0.5
to 3.0 mm thick. The thickness of the cover and the resilient layer
are adjusted to meet different bounce and softness requirements.
Both closed cell and open cell foams can be used. Multiple layers
of resilient material, e.g., a foamed layer and a non-foamed layer,
may be used if desired.
[0029] Thus, the carcass includes a web layer interposed between
two layers of resilient material (the bladder and the resilient
layer). This structure can support high stress and resist high
impact forces. In addition to strengthening the bladder, this
structure also allows the carcass to support the ball cover.
Therefore, the major stress-supporting area of the sports ball is
the carcass, which is strong enough to resist and absorb most of
the impact encountered during use.
[0030] The carcass is sufficiently strong to resist deformation
resulting from high internal pressure, e.g., from over-inflation,
so less stress is put on the cover sewing threads 28 when the ball
is inflated, and as a result the ball cover is less subject to
damage or fatigue by over-inflation. The carcass can retain its
normal inflated shape (typically, the shape the carcass had
immediately after the resilient layer was applied, during
manufacturing), and thus can support the ball cover in a desired
round shape, even when the ball is over-inflated. Typically, the
ball can be inflated to about 15-20% over the standard pressure of
the sports ball, e.g., to 9.8 to 13.8 psi before the roundness of
the ball will be appreciably affected. Moreover, the supporting
force applied by the carcass to the ball cover is more evenly
distributed, further enhancing the roundness and durability of the
ball.
[0031] The strength imparted by the carcass also allows reduction
or elimination of the bulk of the supporting linings used in
conventional ball covers (lining layer(s) 18, shown in FIGS. 1 and
2), as discussed above. Accordingly, the overall thickness and the
hardness of the ball cover material in the sports balls of the
invention are generally reduced relative to conventional ball
covers that include multiple lining layers, due to the absence of
the additional supporting lining layers. Generally, the thickness
of the ball cover material is less than about 5 mm. However, the
thickness of the foam portion of the ball cover material is
generally somewhat greater than the foam thickness that is used
with a conventional bladder, to provide the ball with good softness
and shape. Typically the ball cover material is about 1 to 1.5 mm
thicker than a conventional synthetic leather without any
additional lining layers. Typically, the ball cover materials used
with the carcass 42 have a thickness of from about 2.5 to 3.5 mm.
The panels 14 are thinner and softer than conventional panels with
additional lining layers, thus permitting the panels to be easily
machine stitched. A skilled sewing machine worker can typically
complete the sewing process of an average of 50 sports balls within
one working day. As a result, the balls can be mass-produced at a
relatively low manufacturing cost. The softer ball cover material,
combined with the resilient layer of the carcass, also provides
good user comfort during play, as discussed above.
[0032] Although additional lining layers (layer(s) 18, FIG. 1) can
be omitted entirely, if it is desired that the ball maintain a
substantially perfectly spherical shape and/or very high impact
resistance, at least one layer of lining, e.g., made of cotton or
polyester, may be attached to the inner lining layer of the
synthetic leather material before cutting the material into panels.
Including one or more supporting linings provides a very high
quality ball, such as would be used in high-level competition.
Advantageously, the ball quality will be similar to that of a
hand-stitched ball, even if the ball is machine stitched. These
machine-stitched balls can have great shape retention and impact
resistance. The roundness can be controlled very well because of
the wound bladder. It may reach the standard of FIFA Approved
level, which is very difficult for conventional machine stitched
balls to achieve. Because the balls can be machine stitched in mass
production, labor costs are advantageously low.
[0033] If the sports ball is made of natural leather, because of
the carcass structure the expensive leather panels can be made
thinner to reduce cost while still providing a good quality ball.
For example, suitable natural leather panels have a thickness of
less than about 1.5 mm, e.g., from about 0.5 to 1.5 mm.
[0034] A manufacturing process that is suitable for production of
the sports ball is shown schematically in FIGS. 6-6I. First, as
shown in FIG. 6, a bladder 42 is inflated, e.g., to a circumference
of about around 67.5 cm for an official size 5 soccer ball, a
little smaller than the circumference of the finished ball when
used in play. Next, elongated reinforcing threads 43, e.g., nylon
threads, coated with glue (not shown) are wound evenly around and
around an outer surface of the bladder until the bladder is covered
by a web layer 46 (FIG. 6A). Panels 49 of a resilient layer 48,
which may be an elastomeric or foam material, as discussed above,
are then laminated to the surface of the web layer, by adhesive or
other suitable lamination techniques (FIG. 6B), to form a carcass
42.
[0035] If the resilient layer is a rubber or other
curable/vulcanizable elastomer, the carcass may be heated in a mold
M (FIG. 6C) until the web layer and the resilient layer are
permanently bonded to each other and the outer surface of the
bladder. The curing time and temperature will be determined based
on the resilient material that is used, as is understood by those
skilled in the art. A suitable curing schedule is from about 3 to 5
minutes per ball at about 160.degree. C. This step is generally
omitted if a foam material is used as the resilient layer. If a
foam is used, the foam layer will generally simply be adhered to
the web layer with adhesive.
[0036] Next, a ball cover material, such as leather or synthetic
leather, is cut into a predetermined number of panels 14 (FIG. 6D).
For example, for a soccer ball, 12 pieces of pentagonal panel and
20 pieces of hexagonal panels are cut. For a volleyball, 18 pieces
of panel in two kinds of rectangular shapes are cut. As discussed
above, if a very high quality ball is desired, at least one layer
of lining material may be adhered on the inner surface of the
synthetic leather material before it is cut into panels.
[0037] To form the ball cover 12, the panels 14 are stitched
together edge-to-edge, e.g., by machine stitching (FIGS. 6E and
6F). A valve hole 50 is left open, and a seam between panels is
also left open to provide an opening 52 to receive the carcass
(FIG. 6F). At this point, the ball cover is inside out. The ball
cover is heated, e.g., to about 50 to 60.degree. C., and then
turned right side out (FIG. 6G). Heating softens the panels so that
the finished ball cover will have a smooth, spherical shape,
without angles at the intersections of the panels.
[0038] Next, the carcass 42 is deflated sufficiently so that the
carcass will fit through a seam opening 52, and inserted into the
ball cover 12 through the opening 52 (FIG. 6H). The valve stem 30
of the bladder is aligned correctly with the valve hole 50 and the
valve stem is glued in place. The rest of the carcass remains
unattached to the ball cover 12. Before the opening 52 is closed,
the carcass may be partially inflated, if desired, to ensure that
the carcass adequately supports the ball cover.
[0039] Finally, the opening 52 is sewn up, typically by hand, to
complete the finished sports ball (FIG. 61).
[0040] General training balls made as described above, with no
additional lining layers, will meet, or be very close to meeting,
FIFA Inspected criteria. Match balls, e.g., balls made as described
above with one or more additional lining layers, meet the FIFA
Approved criteria.
[0041] Other embodiments are within the scope of the following
claims.
[0042] For example, the inflatable bladder may be formed of a
flexible plastic material, such as polyvinyl chloride (PVC) or
polyurethane. The plastic may be provided in the form of a sheet
that is cut into panels that are heat sealed together to a
spherical shape to form the bladder.
* * * * *