US20030069097A1

US20030069097A1 - American football with thin cover

Info

Publication number: US20030069097A1
Application number: US09/972,466
Authority: US
Inventors: Douglas Guenther; Bradley Gaff
Original assignee: Wilson Sporting Goods Co
Current assignee: Wilson Sporting Goods Co
Priority date: 2001-10-05
Filing date: 2001-10-05
Publication date: 2003-04-10

Abstract

A football is provided with a thinner cover than conventional footballs. The thickness of the cover is less than 1.25 mm. The cover is formed from four cover panels. Each cover panel is stitched to a liner panel to form four panel assemblies. The liner panels are stronger and more resistant to bending than conventional liner panels. The panel assemblies are stitched together to form the seams of the football. An inflatable bladder is inserted inside of the attached panel assemblies. The liner panels withstand most of the forces on the football which are created by the internal bladder pressure and by impacts. The relatively thin cover panels are not required to support significant loads.

Description

BACKGROUND

This invention relates to American footballs, and, more particularly, to a football which includes a thinner, and therefore less expensive, cover.

Conventional American footballs include an inflatable bladder and a cover assembly which surrounds the bladder. The cover assembly maintains the shape of the football. The cover assembly is therefore required to support the internal load or expansive force which is imposed on the cover assembly by the pressurized bladder and external forces which are imparted by kicks and by impacts with the ground and other objects.

Conventional cover assemblies for footballs are formed from four panel assemblies which have a generally elliptical shape. Each panel assembly includes a cover panel and a liner panel which are stitched together. The cover panels are usually formed from leather, although synthetic leather and other materials can also be used. The liner panels may be formed from cloth and possibly also a binding material such as rubber, vinyl, or a polycarbonate.

The leather cover panels are intended to support almost all of the forces on the football. Accordingly, leather cover panels are usually relatively thick, for example, at least about 1.6 mm.

The liner panels are not primary load-bearing members. The principal purpose of the liner is to provide a protective layer between the bladder and the cover panels. Accordingly, liner panels are usually relatively thin, have relatively low tensile strength, and can be easily bent.

The cover assembly is formed by stitching the edges of the four panel assemblies with the liner side facing outward. A portion of the adjoining edges of two of the panel assemblies are left unstitched to provide a bladder opening. The cover assembly is then turned inside out through the bladder opening so that the liner side is on the inside and the cover side is on the outside. The stitched edges are inside of the cover assembly, and the in-turned edges form four smooth exterior seams. The bladder is inserted into the cover assembly through the bladder opening, and the bladder opening is laced closed. The bladder is then inflated.

The combined strength of the cover panels and the liner panels control the shape and durability of the football. However, the cover panels provide most of the strength for controlling shape and durability.

The cover panels are the most expensive components of footballs. The cost of the cover panels is directly proportional to the thickness and quality of the material.

SUMMARY OF THE INVENTION

The invention provides a thicker, stiffer liner which provides most of the strength for controlling the shape and durability of the football. Since the cover is not required to withstand any significant loads, the cover can be made relatively thin, for example, less than 1.25 mm. and preferably 0.80 mm or less. The use of a thinner cover reduces the cost of the football significantly without sacrificing shape or durability.

The thicker, stiffer liner is more resistant to bending than conventional liners. The new liner therefore provides the football with a cross sectional shape which is more rectangular and less round because the panels are flatter between the seams. The more rectangular shape provides a better grip, and the flatter panels makes the ball easier to kick.

DESCRIPTION OF THE DRAWING

The invention will be explained in conjunction with an illustrative embodiment shown in the accompanying drawing, in which [0011]
FIG. 1 illustrates a football with the inventive cover assembly; [0012]
FIG. 2 is an enlarged fragmentary sectional view taken along the line [0013] 2-2 of FIG. 1;
FIG. 3 is a plan view of one of the cover panels; [0014]
FIG. 4 is an enlarged fragmentary sectional view taken along the line [0015] 4-4 of FIG. 3;
FIG. 5 is a plan view of one of the liner panels; [0016]
FIG. 6 is a fragmentary sectional view taken along the line [0017] 6-6 of FIG. 5;
FIG. 7 is a view similar to FIG. 6 of a modified liner panel; [0018]
FIG. 8 illustrates a liner panel stitched to a cover panel to form a cover panel assembly; [0019]
FIG. 9 is a fragmentary sectional view taken along the line [0020] 9-9 of FIG. 8;
FIG. 10 illustrates a pair of cover panel assemblies stitched together along overlying edges on one of the sides thereof; [0021]
FIG. 11 is an enlarged fragmentary sectional view taken along the line [0022] 11-11 of FIG. 10; and
FIG. 12 is a fragmentary sectional view of the cover assembly of FIG. 2 before the bladder is inserted.[0023]

DESCRIPTION OF SPECIFIC EMBODIMENT

Referring to FIG. 1, an [0024] American football 15 includes four cover panels 16 which are joined along seams 17. The panels are not secured along a portion of one of the seams to provide a bladder opening which is closed by a lacing 18. The football 15 has the general shape of an oblate spheroid and includes a pair of ends or noses 19 and a longitudinal centerline or axis A.
Referring to FIG. 2, a [0025] cover assembly 22 is formed by four cover panel assemblies 23. Each cover panel assembly 23 includes a cover panel 16 and a liner panel 24. The edges 25 of the cover panels 16 and liner panels 24 are turned inwardly, and the edges 25 of adjacent cover panel assemblies 23 are stitched together by stitching 26.
A conventional [0026] inflatable bladder 28 is enclosed by the cover assembly 22. The bladder 28 is inflated through a valve 29 (see FIG. 1) which extends through the cover assembly 22.
One of the [0027] cover panels 16 is illustrated in FIGS. 3 and 4. Each cover panel 16 is generally elliptical and includes an outer surface 31 and an inner surface 32. The outer surface 31 includes conventional pebbles 33.
The [0028] cover panels 16 used in top quality footballs are made from leather. However, cover panels 16 can also be made from synthetic leather or other materials. Suitable synthetic leather materials are described in Japanese Patent Publication Nos. 60-17871, 62-44074, 63-5518, and 64-20866 and U.S. Pat. Nos. 5,310,178 and 6,024,661.
As will be explained more fully hereinafter, the [0029] cover panels 16 are not required to support any significant portion of the forces which are imposed on the football 15, either by the pressurized bladder 28 or by kicks or other impacts. The cover panels 16 can therefore be substantially thinner than conventional cover panels and can have substantially less strength as measured by tensile strength or any other physical measurement.
[0030] Cover panels 16 made from leather preferably have a thickness of less than 1.25 mm, more preferably less than 1.00 mm, and even more preferably 0.80 mm or less. Covers made from synthetic leather and other materials can have the same thickness.
One of the [0031] liner panels 24 is illustrated in FIGS. 5 and 6. Each liner panel 24 is generally elliptical and includes an inner layer 36 and an outer layer 37. The inner layer 36 is preferably formed from woven fabric, for example, polyester cotton fabric. Other materials can also be used, such as, for example, non-woven fabric. The outer layer 37 is preferably formed from natural or synthetic rubber. However, the outer layer can be formed from other polymeric material, for example, polyurethane or polyvinyl chloride. The material of the outer layer 37 can also be a foam material. The outer layer 37 is preferably bonded to or molded with the fabric inner layer 36 so that the polymeric material diffuses into the mesh of the fabric and mechanically bonds or integrates with the fabric.
FIG. 7 illustrates another embodiment of a [0032] liner panel 39. The panel includes inner and outer layers 40 and 41 of woven fabric and an intermediate layer 42 of rubber or other polymeric material which is bonded to the fabric layers.
FIGS. 8 and 9 illustrate one of the [0033] cover panel assemblies 23. The cover panel 16 and a liner panel 24 are stitched together around their peripheries by a stitching 44. The rubber layer 37 faces the cover panel 16, and the fabric layer 36 forms the inside layer of the cover panel assembly. If desired, however, the liner panel 24 can be reversed so that the rubber layer forms the inside layer of the cover panel assembly.
The [0034] cover assembly 22 is formed by stitching together cover panel assemblies 23. FIGS. 10 and 11 illustrate a pair of cover panel assemblies 23 a and 23 b stitched together by a stitching 26 along one side edge 46 of each of the cover panel assemblies 23. The other side edges 47 of the cover panel assemblies 23 a and 23 b are not secured to each other. As is well known in the art, the cover panel assemblies 23 are secured in an inside out position in which the cover panels 16 of the cover panel assemblies face each other.
The other two [0035] cover panel assemblies 23 are secured to the cover panel assemblies 23 a and 23 b in the same manner to form an inside out cover assembly which includes an opening for the bladder 28. The inside out cover assembly is then turned inside out through the bladder opening to form the cover assembly 22 which is illustrated in FIG. 12.
The [0036] liner panels 24 have significant stiffness and resistance to bending because of the combination of the fabric and rubber layers. As a result, the cover panel assemblies 23 are relatively flat between the seams 17, and the cover assembly 22 has a substantially rectangular transverse cross section as illustrated in FIG. 12. In FIG. 12, the cover panel assemblies 23 extend in substantially straight lines between the seams 19.
Representative prior art liner panels had a tensile strength of about 4000 psi and a drape angle of about 40 to 60 degrees. Drape angle measures the stiffness of a liner panel by extending half of the long length of a liner panel over an edge and measuring the angle that it drapes down. [0037]
In contrast, the [0038] liner panels 24 of the invention have a tensile strength of at least 5500 psi, and preferably at least 7500 psi, and a drape angle of less than 30 degrees, and preferably less than 20 degrees. Additionally, the liner panels preferably have a thickness of at least 0.70 mm.
After the [0039] bladder 28 is inserted into the cover assembly 22 and inflated, the cover panel assemblies 23 will be forced outwardly somewhat as illustrated in FIG. 2. However, each of the cover panel assemblies 23 will still be closer to a flat or straight line configuration than to an arcuate configuration which is defined by a circle which circumscribes the seams. The flatter shape of the cover panel assemblies provides a more rectangular cross sectional shape which is easier to grip. The flatter cover panel assemblies 23 are also easier to kick.
When the [0040] cover panel assemblies 23 are stitched together, the liner panels 24 are secured together and form a liner assembly 22, which holds the shape of the football 15. The inventive liner assembly 22 is significantly stronger and stiffer than prior art liner assemblies, and the inventive liner assembly 22 provides all or substantially all of the strength which is required to maintain the shape of the football and to withstand forces which are caused by kicks and other impacts. The cover panels 23 are not required to withstand any significant forces and can therefore be much thinner and weaker than prior art cover panels.
The liners of prior art footballs had a tendency to creep when the footballs were stored because of the expansive forces which are caused by the inflated bladder. The cover panels therefore had to be strong enough to hold the shape of the football. The [0041] inventive liner assembly 22 does not creep and maintains the shape of the football 15 during storage.
While in the foregoing specification a detailed description of a specific embodiment of the invention was set forth for the purpose of illustration, it will be understood that many of the details hereingiven may be varied considerably by those skilled in the art without departing from the spirit and scope of the invention. [0042]

Claims

We claim:

1. A football comprising:

an inflatable bladder,

a liner surrounding the bladder, the liner having a tensile strength of at least 5500 psi, and

a cover attached to the liner, the cover having a thickness of less than 1.25 mm.

2. The football of claim 1 in which the liner has a drape angle of less than 30 degrees.

3. The football of claim 1 in which the cover is leather.

4. The football of claim 1 in which the liner includes a fabric layer and a polymeric layer which is bonded to the fabric layer.

5. The football of claim 4 in which the polymeric layer is rubber.

6. The football of claim 1 in which the cover has a tensile strength of at least 4000 psi.

7. The football of claim 1 in which the cover has a thickness of 0.80 mm or less.

8. The football of claim 1 in which the thickness of the liner is at least 0.70 mm.

9. The football of claim 1 in which the football includes a pair of ends and a longitudinal centerline which extends between the ends and the liner includes four liner panels and the cover includes four cover panels, the liner panels and the cover panels being stitched together along four seams which extend between the ends, transverse cross sections of the football through the seams and the longitudinal centerline having a configuration between each pair of adjacent seams which lies closer to a straight line between the adjacent seams than to an arc of a circle between the seams.

10. A football comprising:

an inflatable bladder,

a liner surrounding the bladder, the liner having a drape angle of less than 30 degrees, and

11. The football of claim 10 in which the liner includes a fabric layer and a polymeric layer which is bonded to the fabric layer.

12. The football of claim 11 in which the polymeric layer is rubber.

13. The football of claim 10 in which the cover has a tensile strength of at least 4000 psi.

14. The football of claim 10 in which the cover has a thickness of 0.80 mm or less.

15. The football of claim 10 in which the thickness of the liner is at least 0.70 mm.

16. The football of claim 10 in which the football includes a pair of ends and a longitudinal centerline which extends between the ends and the liner includes four liner panels and the cover includes four cover panels, the liner panels and the cover panels being stitched together along four seams which extend between the ends, transverse cross sections of the football through the seams and the longitudinal centerline having a configuration between each pair of adjacent seams which lies closer to a straight line between the adjacent seams than to an arc of a circle between the seams.

17. The football of claim 10 wherein the cover is made of a material selected from the group consisting of a natural leather and a synthetic leather.