U.S. patent application number 14/266835 was filed with the patent office on 2014-11-06 for string for sports racquet and sports racquet with improved string.
This patent application is currently assigned to Diadem Sports, LLC. The applicant listed for this patent is Joel Evan Specht. Invention is credited to Joel Evan Specht.
Application Number | 20140329623 14/266835 |
Document ID | / |
Family ID | 51841704 |
Filed Date | 2014-11-06 |
United States Patent
Application |
20140329623 |
Kind Code |
A1 |
Specht; Joel Evan |
November 6, 2014 |
STRING FOR SPORTS RACQUET AND SPORTS RACQUET WITH IMPROVED
STRING
Abstract
In accordance with the embodiments of the present invention, a
resilient and elastic single-filament string for a sports racquet,
and an accompanying complete sports racquet is provided. The string
includes a central body with ridges that extend axially along the
length of said central body, where the ridges and central body are
initially formed as a single homogeneous structure. The sports
racquet incorporates at least one of these single-filament strings,
along with a frame formed of a rigid material containing a number
of holes.
Inventors: |
Specht; Joel Evan; (Boynton
Beach, FL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Specht; Joel Evan |
Boynton Beach |
FL |
US |
|
|
Assignee: |
Diadem Sports, LLC
Boynton Beach
FL
|
Family ID: |
51841704 |
Appl. No.: |
14/266835 |
Filed: |
May 1, 2014 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61818658 |
May 2, 2013 |
|
|
|
Current U.S.
Class: |
473/543 |
Current CPC
Class: |
A63B 51/02 20130101;
A63B 51/026 20200801; D02G 3/444 20130101; A63B 2209/00
20130101 |
Class at
Publication: |
473/543 |
International
Class: |
A63B 51/02 20060101
A63B051/02 |
Claims
1. A resilient, elastic, single-filament string for a sports
racquet, comprising: a central body; and a plurality of ridges that
extend axially along the length of said central body, wherein said
ridges and said central body are created as a single homogeneous
structure.
2. The string according to claim 1, wherein the cross-section of
said central body is substantially circular.
3. The string according to claim 1, wherein each of said plurality
of ridges are spaced from one another evenly about the outer
circumference of said central body.
4. The string according to claim 1, wherein each of said plurality
of ridges are spaced from one another unevenly about the outer
circumference of said central body.
5. The string according to claim 1, wherein the cross-section of
said central body is substantially rectangular.
6. The string according to claim 1, wherein said plurality of
ridges are substantially triangular.
7. The string according to claim 1, wherein said plurality of
ridges are substantially rectangular.
8. The string according to claim 1, wherein said plurality of
ridges are substantially pentagonal.
9. The string according to claim 1, wherein said plurality of
ridges are substantially hexagonal.
10. The string according to claim 1, wherein said plurality of
ridges are substantially octagonal.
11. The string according to claim 1, wherein said plurality of
ridges are substantially semicircular.
12. The string according to claim 1, wherein said string is formed
of a synthetic material selected from the group consisting of
nylon, polyester, Kevlar, Zyex, boron, graphite, Vectran,
Polyolefin, and polyurethane.
13. The string according to claim 1, wherein said string is formed
of a natural gut fiber.
14. The string according to claim 1, wherein said string is coated
by a wear-resistant material.
15. A sports racquet comprising a frame, and at least one
resilient, elastic, single-filament string, the string comprising:
a central body; and a plurality of ridges that extend axially along
the length of said central body, wherein said ridges and said
central body are created as a single homogeneous structure.
16. The sports racquet according to claim 15, wherein the frame is
comprised of a lightweight and rigid material selected from the
group consisting of aluminum, steel, titanium, magnesium, wood,
ceramic, polymer, graphite, carbon composite, and fiberglass
composite.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to U.S. Provisional Patent
Application Ser. No. 61/818,658 titled "STRING FOR TENNIS RACQUET
AND TENNIS RACQUET WITH IMPROVED STRING" filed on May 2, 2013, the
complete subject matter of which is incorporated by reference
herein in its entirety.
FIELD OF THE DISCLOSURE
[0002] A sports racquet string, preferably a tennis racquet string,
and more specifically an improved string configuration that imparts
more spin to a ball upon contact, recovers more quickly from such
contact, maintains its structural integrity for a longer period of
time, and a sports racquet that includes the improved string.
BACKGROUND
[0003] The traditional and most popular cross-section of a sports
racquet string is circular. Such strings are typically made from
natural gut (animal fiber) or from synthetic materials, such as
nylon. Conventionally, strings are constructed by twisting many
fine filaments of these materials together, with or without a
center filament, into a round core strand and then by passing the
core strand through a round die to apply an outer layer coating.
Thus the prior art teaches the use of a multi-filament string. Such
multi-filament strings provide an increase in elasticity over
traditional single-filament synthetic strings, but fall short of
single-filament strings in terms of their durability.
[0004] The prior art also discloses the idea of a multi-filament
string that is not round in cross-section but that ,may include a
plurality of external ribs. These concepts are illustrated and
described, for example, in PCT Application No. PCT/US90/01698,
published as WO 91/11549 in the names of CHEN and LIN.
[0005] As described in the aforementioned PCT Application, it is
generally desirable that the sting exhibits various characteristics
such as small damping, that is, low energy loss and high
resilience, and good elasticity, that is, a low modulus of
elasticity. These elements contribute to the playability of the
string. As an illustration, a low modulus of elasticity promotes
the ability of the player to carefully control the spin and
direction of the balls they hit, thereby providing greater accuracy
and spin amount. It is also desirable that the string be
sufficiently durable. This aspect of durability is the most
troublesome deficiency among all multi-filament string designs.
[0006] The overall diameter of any sports racquet string is very
important, as it affects the durability and playability of the
string. Generally, thin strings have superior playability. Thin
strings exhibit good elasticity, which allows them to maintain
longer contact with the ball for greater control. However, thin
strings may stretch and are more easily broken. On the other hand,
thick strings are stronger and more durable but lack the
playability of thin strings.
[0007] An additional important characteristic of a string is its
ability to impart a spin, preferably top spin, on the ball. The
failure to consistently impart significant top spin frequently
results in the ball traveling greater distance than intended before
hitting the ground. Thus the failure to impart a top spin on the
ball frequently requires that the ball be struck with lesser force,
to limit the distance of travel before the ball hits the ground.
This means hitting shots that are slower, and more easily returned.
More spin allows for more speed.
[0008] To put spin on the ball, the ball is struck with the racket
face at an angle to the flight path and the racket face is moved in
a parallel direction to the plane of the face. Increasing the
friction between the strings and the ball has been thought to
enhance imparting spin on the ball.
[0009] The aforementioned PCT Application, as well as U.S. Pat.
Nos. 4,805,393 ('393 patent) and 4,860,531 ('531 patent), all three
of which are hereby incorporated in their entirety by reference,
each propose variations in string configuration, but suffer from
the limitation that they are unable to provide all of the desired
benefits of the current invention. Rather, the approach taken in
each reference is merely an unsatisfactory compromise in
performance, based on a misunderstanding of the contribution of the
string shape or configuration to the playing of the game.
[0010] The strings mentioned in these references are all comprised
of either fused or bonded multi-filament combinations, or
helically-oriented twisting of a non-circular single-filament. Such
types of string share the disadvantage of not having enough
durability to match their elasticity, and therefore impart a
consistently high amount of spin on a ball after prolonged usage.
The single-filament string described herein maintains a higher
degree of durability compared to the prior art strings, while
simultaneously providing more elasticity than a traditional
single-filament string when contacting a ball. The present
invention's ridged homogenous construction solves the problem of
providing a high degree of playability coupled with a high degree
of overall string durability.
BRIEF SUMMARY OF THE INVENTION
[0011] An improved string for a sports racquet is formed as of a
single-filament or monofilament, not as of a multi-filament
configuration, and includes a plurality of spaced-apart projections
or ridges extending along the length of the string's outer surface
that are formed as part of the string when it is first created. The
ridges may be spaced equally apart from one another around the
circumference of the central string body, and may extend axially
along the outer surface of the single-filament string.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In the drawings, wherein like reference numerals identify
corresponding components:
[0013] FIG. 1A is a perspective illustration of one form of the
racquet string;
[0014] FIG. 1B is a cross-section of one form of the racquet
string;
[0015] FIG. 2 is a cross-section of another form of the racquet
string;
[0016] FIG. 3 is a cross-section of another form of the racquet
string; and
[0017] FIG. 4 is a cross-section of another form of the racquet
string.
DETAILED DESCRIPTION OF THE INVENTION
[0018] In the following description, it is to be understood and
appreciated that while one or more forms of the current invention
are described or illustrated, the present disclosure is not to be
limited to the specific form or arrangement herein described and
shown. It will be apparent to those skilled in the art that various
changes may be made without departing from the scope of the present
contribution and thus the present contribution is not to be
considered limited to what is shown and described in the
specification and/or any drawings or figures included herein.
[0019] Thus any embodiments, methods, procedures and techniques
described herein are merely representative, are intended to be only
exemplary, and are not intended as limitations on the scope of the
claimed invention. Changes therein and other uses will occur to
those skilled in the art, and should be considered as encompassed
within the spirit of the present disclosure. All dimensions,
configurations, materials, etc., should be interpreted in a
non-limiting manner.
[0020] Referring first to FIG. 1A , the present invention is
illustrated as a tennis racquet string 10, presented in a
perspective view. The string 10 is a single-filament having a
central body 12, with a series of spaced-apart, axially or
longitudinally extending ribs or ridges 14. Preferably, the ridges
are equally spaced apart around the circumference of the body 12 of
the string.
[0021] Preferably, the string 10 including the ridges 14 is made as
a single extrusion. The material of the string 10 may be a
PET-based polymer, but any other form of string heretofore used for
tennis racquet strings may be used as well.
[0022] FIG. 1B is a direct cross-sectional illustration of the
string 10, having the central body 12, and the series of distinct
rectangular ribs or ridges 14. In this FIG. 1B, the ribs or ridges
are formed as relatively small rectangular protrusions that extend
perpendicularly from surface of the cylindrical central body
12.
[0023] In another embodiment of the present invention, FIG. 2
illustrates in cross-section a string 20, having a central body 22,
and a series of ridges 26. Six ridges are illustrated, thus the
center-points of each ridge would be spaced 60 degrees apart from
one another, measured radially around the circumference of the
central body 22. In FIG. 2 , the ridges 26 are formed as truncated
triangles, whose bases completely cover the smoothly-curved surface
of the central body 22.
[0024] In another embodiment of the present invention, FIG. 3
illustrates in cross-section a string 30, having a central body 32,
and a series of ridges 38. Six equally-spaced ridges are
illustrated, and thus the ridges would be spaced 60 degrees apart
from one another, measured radially around the circumference of the
single central body 32. The ridges 38 are formed as pointed
triangles, whose bases completely cover the smoothly-curved surface
of the single central body 32.
[0025] In another embodiment of the present invention, FIG. 4
illustrates in cross-section a string 40, having a central body 42,
and a series of ridges 44. The ridges 44 are formed as triangles.
In this embodiment, the ridges 44 are not equally spaced around the
entire circumference of the central body 42, but are instead
present only on one half of the central body's outer surface.
[0026] As noted above, the number of ridges (FIGS. 1A, 1B, 2, 3,
and 4) as well as the ridge configuration (e.g., rectangular (FIGS.
1A and 1B) or pointed (FIGS. 3 and 4)) is described in general,
non-limiting terms. More or fewer ridges, and different
configurations or shapes that make contact with the ball, are
within the spirit and scope of the present disclosure.
[0027] The inventor has determined that the configurations of the
present invention generally described herein provide numerous
advantages over the prior art. For example, while the ridges are
compressed upon impact with the ball, the sting recovers or resumes
its normal configuration more quickly, thus imparting greater spin
to the ball. The ridged-configuration of the present invention
results in more friction between the ball and each string, due to a
pinching effect that results from the deformation of the
ridged-shape of the string upon contact with the ball, and a
decrease in friction between the horizontal and vertical racquet
strings because of the smaller contact area of between each string.
The degree of deformation of strings when contacting a ball changes
the amount of string surface area that the ball is in contact with.
More contact translates to a higher degree of friction, and thus a
greater ability to impart spin upon the ball.
[0028] The increase in playability is enhanced by the fact that the
present invention is formed as a single monofilament extrusion,
where the ridges and the central body are formed as one structure
when the string is first created. This allows for greater ridge
deformation and an improvement in overall string consistency,
elasticity, and resilience.
[0029] The present invention provides an enhanced surface area for
ball contact, not only by virtue of the fact that the strings
themselves have more surface area due to their ridged surfaces, but
also because the ridges may deform to a greater degree upon ball
contact. These same ridges also allow the strings to touch each
other with a smaller contact point, thus allowing for greater
string mobility when installed in a racquet. The prior art
attempted to accomplish the same goal with a combination of outer
string structures that were fused or bonded to a central string,
after the central core (or cores) of the string had already been
formed. Having ridges initially formed with the central body as a
monofilament string allows for improvements in elasticity,
resilience, and playability.
[0030] It is the combination of greater ridge deformation and
smaller inter-string contract that imparts more spin than prior
configurations. The present configuration allows for more movement
of the strings due to fewer contact points between the horizontal
and vertical racquet strings, and therefore less friction on the
strings. However, there is greater friction between the ball and
the ridged-strings, due to the increase in surface area that the
ball may deform onto when contacting the string, so that a greater
benefit of the friction (i.e., all of the energy imparted upon
movement or deformation of the string) may be imparted to the
ball.
[0031] A typical sports racquet has a fixed number of
horizontally-oriented strings, and a fixed number of
vertically-oriented strings within its face, with the strings
extending through grommets and holes found within the frame. The
present string may be greater in overall diameter than conventional
strings, because of its ridges or ribs, thus allowing for larger
holes in the racquet frame. Larger holes mean an overall reduction
in the weight of the racquet, as well as the use of fewer strands
of crossing string in the face of the racquet, thereby reducing the
density of a racquet's string pattern.
[0032] In one embodiment of the present invention, the strings may
be spiral wound or twisted either during creation or installation,
to impart even more spin to the ball.
[0033] Typically, a sports racquet string may have a diameter of
between about 1.00-1.30 millimeters. The ridges heretofore proposed
for multi-filament strings are of approximately 0.25 millimeters in
height, from the surface of the central string body. Thus, a string
described in the prior art could have an overall cross-sectional
diameter as great as 1.80 millimeters, i.e., the core thickness
added to the height of two ridges opposed form one another by 180
degrees measured around the circumference of the central string
body. As noted above, the present invention may thus be thicker
than the prior art strings, but still enjoy the benefits provided
by a substantially elastic string of a thinner overall
diameter.
[0034] Many synthetic materials are available for use in sports
racquet strings, including but not limited to: Nylon, Polyester,
Kevlar, Zyex (polyetheretherketon), Boron, Graphite Fiber, Vectran,
Polyolefin, and Polyurethane.
* * * * *