U.S. patent application number 13/491787 was filed with the patent office on 2013-10-17 for stringing device for sports racket.
The applicant listed for this patent is Jung-Shih CHANG. Invention is credited to Jung-Shih CHANG.
Application Number | 20130274038 13/491787 |
Document ID | / |
Family ID | 49325587 |
Filed Date | 2013-10-17 |
United States Patent
Application |
20130274038 |
Kind Code |
A1 |
CHANG; Jung-Shih |
October 17, 2013 |
STRINGING DEVICE FOR SPORTS RACKET
Abstract
A stringing device for a sports racket includes a base and a
cleat. The base has a pair of opposing side ends, an upper surface
and a bottom surface. The base further has a guiding groove with an
open end and a string engaging surface. The cleat extends downward
from the bottom surface of the base and has a guiding channel with
an inlet and an outlet. The inner diameter of the guiding channel
is larger than the outer diameter of the racket string. The string
engaging surface of the guiding groove has a suspending portion
corresponding to the inlet of the guiding channel for guiding a
racket string entering/exiting from the open end of the guiding
groove to thread through the guiding channel from the inlet or
outlet thereof without touching the inner wall of the guiding
channel.
Inventors: |
CHANG; Jung-Shih; (Taichung
City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CHANG; Jung-Shih |
Taichung City |
|
TW |
|
|
Family ID: |
49325587 |
Appl. No.: |
13/491787 |
Filed: |
June 8, 2012 |
Current U.S.
Class: |
473/557 |
Current CPC
Class: |
A63B 49/022 20151001;
A63B 51/015 20151001 |
Class at
Publication: |
473/557 |
International
Class: |
A63B 51/14 20060101
A63B051/14 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 16, 2012 |
TW |
101113488 |
May 8, 2012 |
TW |
101116399 |
Claims
1. A stringing device for a sports racket, comprising: an elongated
base having opposing longitudinal side ends, a longitudinal upper
surface and a longitudinal bottom surface opposed from said upper
surface, each of said surfaces extending between said opposing
longitudinal ends; said base further having a guiding groove
running longitudinally along said upper surface thereof, said
groove having an open end and a string engaging surface, said open
end located at one of said side ends of said base; a cleat
extending downward from said bottom surface of said base, said
cleat having a guiding channel through which a racket string
threads, said guiding channel having an inlet disposed on said
string engaging surface of said guiding groove, an outlet opposed
from said inlet, and an inner diameter being larger than the outer
diameter of a string threading therethrough; and said string
engaging surface of said guiding groove having a suspending portion
corresponding to said inlet of said guiding channel for guiding a
racket string to thread through said guiding channel without
touching the inner wall thereof.
2. The device according to claim 1, wherein said suspending portion
is a projecting area.
3. The device according to claim 2, wherein said suspending portion
has a curved bearing surface.
4. The device according to claim 2, wherein the diameter of said
inlet is smaller than that of said outlet.
5. The device according to claim 1, wherein said cleat extends at
least partially through a string hole of a racket.
6. A sports racket, comprising a head frame defining an opening, a
plurality of string holes formed in said head frame toward said
opening and at least a string device of claim 1, said string device
being disposed on said head frame in such a way that said cleat
thereof is at least partially and tightly inserted into one of said
string holes.
7. A stringing device for sports racket, comprising: an elongated
base having opposing longitudinal side ends, a longitudinal upper
surface and a longitudinal bottom surface opposed from said upper
surface, each of said surfaces extending between said opposing
longitudinal ends; said base further having a guiding groove
running longitudinally along said upper surface thereof, said
guiding groove having opposing longitudinal open ends, a first
string engaging surface and a second string engaging surface, each
of said open ends respectively corresponding to each of said side
ends of said base, and each of said string engaging surface
respectively corresponding to each of said open ends; a cleat
extending downward from said bottom surface of said base, said
cleat having a guiding channel through which a racket string
threads, said guiding channel having an inlet disposed between said
first string engaging surface and said second string engaging
surface, an outlet opposed from said inlet, and an inner diameter
being larger than the outer diameter of the racket string threading
therethrough; said first string engaging surface of said guiding
groove having a first suspending portions corresponding to said
inlet of said guiding channel for guiding a racket string entering
from one of said open ends of said groove to thread through said
guiding channel without touching the inner wall thereof, and said
second string engaging surface of said guiding groove having a
second suspending portion opposing said first suspending portion
for guiding a racket string entering from the other of said open
ends of said groove to thread through said guiding channel without
touching the inner wall thereof.
8. The device according to claim 7, wherein each of said suspending
portions is a projecting area.
9. The device according to claim 8, wherein each of said suspending
portions has a curved bearing surface.
10. The device according to claim 8, wherein the diameter of said
inlet is smaller than that of said outlet.
11. The device according to claim 7, wherein said cleat extends at
least partially through a string hole of a sports racket.
12. A sports racket, comprising a head frame defining an opening, a
plurality of string holes formed in said head frame toward said
opening and at least a string device of claim 7, said string device
being disposed on said head frame in such a way that said cleat
thereof is at least partially and tightly inserted into one of said
string holes.
13. A stringing device for sports racket, comprising: an elongated
base having opposing longitudinal ends, a longitudinal upper
surface and a longitudinal bottom surface opposed from said upper
surface, each of said surfaces extending between said opposing
longitudinal ends; a pair of cleats respectively disposed at each
of said opposing longitudinal ends of said base and extending
downward from said bottom surface of said base, each of said cleats
having a guiding channel through which a racket string threads,
said guiding channel having an inlet near one of said opposing
longitudinal ends of said base, an outlet opposed from said inlet,
and an inner diameter being larger than the outer diameter of a
racket string threading therethrough; said base further having a
guiding groove running longitudinally along said upper surface
thereof, said guiding groove having opposing longitudinal open ends
and a string engaging surface disposed between said open ends for
engaging and receiving a string which is looped thereover; and said
string engaging surface of said guiding groove having a pair of
suspending portions, each of said suspending portions disposed near
each of said open ends and corresponding to said inlet of said
guiding channel of each of said cleats for guiding a racket string
to thread through said guiding channel without touching the inner
wall thereof.
14. The device according to claim 13, wherein each of said
suspending portions is a bulge.
15. The device according to claim 14, wherein each of said
suspending portions has a curved bearing surface.
16. The device according to claim 14, wherein the diameter of said
inlet is smaller than that of said outlet.
17. The device according to claim 13, wherein each of said cleats
extends at least partially through a string hole of a sports
racket.
18. A sports racket, comprising a head frame defining an opening, a
plurality of string holes formed in said head frame toward said
opening and at least a string device of claim 13, said string
device being mounted on said head frame in such a way that each of
said pair cleats thereof is respectively at least partially and
tightly inserted into one of an adjacent pair of said string holes.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to strung sports rackets, for example
tennis, squash or badminton rackets, and more particularly to a
stringing device for strung sports rackets.
[0003] 2. Description of the Related Art
[0004] It is well known that the most conventional sports racket
has a common, general construction in which a head coupled to a
grip via a yoke has a substantially oval shape defining a face
formed by a latticework of strings. The head of such prior art
rackets is usually constructed to have a set of string holes to be
passed by the strings to form the latticework. This effectively
divides the strings into individual and isolated string chords
which span the head. Such an anchored string relationship causes
high dynamic tension along individual string chords during impact
with resulting a poor performance of a sport racket, including a
smaller string deflection and shorter dwell time.
[0005] U.S. Pat. Nos. 4,591,165 and 4,930,782 to Karakal teach a
rigid rocker member installed between the string and the supporting
portion of the racket head to transmit tension from one string
chord to an associated string chord. This structure eliminates
frictional contact between the string chords and the racket head
and causes tension in the impacting string chords to be transferred
to other or all additional string chords in the racket. The result
is that the sports racket with such a rocker member can provide
greater efficiency of energy storage and allows more of the kinetic
energy of the ball to be stored in the racket during impact.
[0006] However, such an assembly still has problems. For instance,
it was difficult to retain individual rockers in place during
stringing. A broken string could result in some or all of the
rockers being lost from the racket, and possibly scattered over a
playing court. Restringing involved the same problems as original
assembly, while also requiring the need for the user or repairer to
stock spare rockers to replace those lost after a string break. In
addition, while the rocker member rocks in response to different
amounts of force applied by the associated string chords, as shown
in FIG. 11 of U.S. Pat. No. 4,930,782, the string chords passing
through the string holes of the racket will contact or be secured
against the inner-wall thereof. This means that the friction
between the string chords and the racket head will not be
eliminated by the rocker member and the tension in the impacting
string chords cannot be smooth and averagely transferred to other
string chords in the racket.
SUMMARY OF THE INVENTION
[0007] The object of the present invention is to provide a
stringing device for a sports racket which can effectively reduce
the friction between the string chords and the head of the sports
racket and in the same time simplify the stringing operation of the
sports racket.
[0008] To achieve this object, a stringing device embodied
according to the present invention includes an elongated base and a
cleat extending from the base. The device may be made of light
weight and rigid materials, such as aluminum alloy, titanium alloy
or FRP. The base has a pair of opposing longitudinal side ends, a
longitudinal upper surface and a longitudinal bottom surface
opposed to the upper surface. Each of the surfaces extends between
the opposing longitudinal side ends. The base further has a guiding
groove running longitudinally along the upper surface. The groove
has an open end and a string engaging surface. The cleat extends
downward from the bottom surface of the base and has an outer
diameter being slightly smaller than the inner diameter of the
string holes of a sports racket so as to be inserted thereinto when
the stringing operation is proceeded. The cleat further has a
guiding channel through which a racket string threads. The guiding
channel has an inlet connected with the string engaging surface of
the guiding groove of the base and an outlet opposed to the inlet.
The inner diameter of the guiding channel is larger than the outer
diameter of the racket string. In addition, the string engaging
surface of the guiding groove of the base has a suspending portion
corresponding to the inlet of the guiding channel for guiding a
racket string entering/exiting from the open end of the guiding
groove to thread through the guiding channel from the inlet or
outlet thereof without touching the inner wall of the guiding
channel. Specially, the suspending portion may be a bulge or a horn
projecting from the string engaging surface and extending into the
inlet of the guiding channel so that the racket string is in a
suspending way to thread through the guiding channel without
touching the inner wall thereof.
[0009] The objects of the present invention are also achieved with
the aid of a stringing device which comprises an elongated base and
a pair of cleats. The base includes opposing longitudinal ends, a
longitudinal upper surface and a longitudinal bottom surface
opposed from said upper surface, each of said surfaces extending
between said opposing longitudinal ends. The base further has a
guiding groove running longitudinally along the upper surface
thereof. The guiding groove has opposing longitudinal open ends and
a string engaging surface disposed between the open ends for
engaging and receiving a string which is looped thereover. Each of
the cleats is respectively disposed at each of the opposing
longitudinal ends of the base and extends downward from the bottom
surface of the base. Each of the cleats also has a guiding channel
through which a racket string threads. The guiding channel has an
inlet connected with the string engaging surface and an outlet
opposed to the inlet. The inner diameter of the guiding channel is
larger than the outer diameter of a racket string threading
therethrough. Furthermore, the string engaging surface of the
guiding groove of the base is constructed to have a pair of
suspending portions, each of the suspending portions corresponding
respectively to the inlet of the guiding channel of each of the
cleats for guiding a racket string to thread through the guiding
channel without touching the inner wall thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The embodiments of the present invention will be described
below with reference to the drawings, wherein:
[0011] FIG. 1 is a front view of a sports rackets with portions
broken away to illustrate features of the present invention;
[0012] FIG. 2 is a perspective view of a first embodiment of the
present invention;
[0013] FIG. 3 is an enlarged view of A portion of FIG. 1;
[0014] FIG. 4 is a perspective view of a second embodiment of the
present invention;
[0015] FIG. 5 is an enlarged view of a broken portion of a sports
racket equipped with the second embodiment shown in FIG. 4;
[0016] FIG. 6 is a perspective view of a third embodiment of the
present invention;
[0017] FIG. 7 is an enlarged view of a broken portion of a sports
racket equipped with the third embodiment shown in FIG. 6;
[0018] FIG. 8 is a perspective view of a fourth embodiment of the
present invention; and
[0019] FIG. 9 is an enlarged view of a broken portion of a sports
racket equipped with the fourth embodiment shown in FIG. 8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] FIG. 1 shows a tennis racket equipped with a stringing
device embodied according to the present invention to form a string
face. The racket is generally designated by the reference numeral
90. Tennis racket 90 includes an elongated handle 92, a head frame
94 connected to one end of handle 92 and a handgrip 96 connected to
another end of handle 92. Head frame 94 is planar with handle 92.
Tennis racket 90 may be made from fiber reinforced plastic
materials or any suitable materials.
[0021] Head frame 94 includes an outer surface 942, an inner outer
surface 944 and an annular channel 946 extending along outer
surface 942. Inner surface 944 defines a string opening 98. A
plurality of string holes are formed through head frame 94 into
string opening 98. String 100 is threaded through head frame 94
using string holes to form an impacting string face.
[0022] String holes are usually arranged in two groups. A first,
longitudinal group of string holes 102 may be formed through head
frame 94 along parallel longitudinal axes and spaced across head
frame 94 to receive portions of the longitudinal string chords. A
second or transverse group of string holes 104 may be formed
through head frame 94 along transverse axes and preferably parallel
to one another to receive portions of the transverse string
chords.
[0023] A stringing device 10 embodied according to the present
invention is shown in detail in FIGS. 2-3. Stringing device 10 may
be made of any suitable rigid materials. In this embodiment, it is
made of aluminum alloy.
[0024] Stringing device 10 includes an elongated base 12 and a pair
of cleats 14. Base 12 has a longitudinal upper surface 16, a
longitudinal bottom surface 18 and a guiding groove 20 running
longitudinally along upper surface 16. Guiding groove 20 has a pair
of opposing longitudinal open ends 202 and a string engaging curved
surface 204 disposed between open ends 202 for engaging and
receiving a string chord 106 which is looped thereover.
[0025] Cleats 14 are arranged to be inserted into two adjacent
string holes, although other arrangements are possible. Each of
cleats 14 respectively extends downward from bottom surface 18 of
base 12 and has a guiding channel 142 with an inlet 144, an outlet
146 opposed to inlet 144 and an inner diameter being larger than
the outer diameter of racket string 100 so that it can thread
therethrough.
[0026] Furthermore, string engaging surface 204 of guiding groove
20 is constructed to have a pair of bulges 30. Each of bulges 30
has a curved bearing surface 302 and is arranged to correspond to
inlet 144 of guiding channel 142 of each of cleats 14 for guiding a
racket string 100 to thread through guiding channel 142 without
touching inner wall 148 thereof. Specially, each of bulges 30
extends slightly into inlet 144 of guiding channel 142 so that the
diameter of inlet 144 is smaller than that of outlet 144. This will
always ensure the best possible suspending of the string threading
through guiding channel 142 along the axis thereof without thereby
touching inner wall 148 thereof.
[0027] Stringing device 10 can be used on a tennis racket or other
appropriate strung sports rackets. In this embodiment, device 10 is
mounted on racket 90 in such a way that base 12 is installed
between string chord 106 and the bottom surface of annular channel
946 of head frame 94 and each of cleats 14 is tightly inserted into
each of two adjacent string holes 102. String loop 106 connecting
two vertical strings is received over engaging curved surface 204
of guiding groove 20.
[0028] As described above, when threading through each of guiding
channel 142 of cleats 14, each of two vertical strings connected by
loop 106 will firstly be suspended by each of bulges 30 and then
enter into guiding channel 142 from inlet 144 without touching
inner wall 148 thereof. Thus, the objects or advantages of the
present invention can be achieved.
[0029] FIGS. 4 and 5 show an alternative stringing device 40
embodied according to the present invention. Device 40 is
substantially the same as device 10 described above. Device 40
differs from device 10 solely with regard to the structure of cleat
42. In this embodiment, cleat 42 has a length being shorter than
that of cleat 14 of device 10 so that when device 40 is mounted on
racket 90, cleat 42 thereof is inserted into just a portion of
string hole 102 of racket 90. This ensures that the diameter of the
inlet of string hole 102 is smaller than that of the outlet thereof
so that string chord threads through guiding channel 50 without
touching inner wall 52 of cleat 42. Furthermore, in this
embodiment, cleat 42 has a body 46 with an elongated opening 48. As
shown in FIG. 5, this also ensures that string chord threading
through guiding channel 50 will not touch inner wall 52 of cleat
42.
[0030] FIGS. 6 and 7 show a further alternative stringing device 60
embodied according to the present invention. Stringing device 60
includes an elongated base 62 and a cleat 64. Base 62 has a
longitudinal upper surface 622, a longitudinal bottom surface 624
and a guiding groove 626 running longitudinally along upper surface
622. Guiding groove 626 has an open end 628 and a string engaging
surface 630.
[0031] Cleat 64 is designed to be inserted into one of string holes
102. Cleat 64 extends downward from bottom surface 624 of base 62
and has a guiding channel 642 with an inlet 644 located on engaging
surface 630, an outlet 646 opposed to inlet 644 and an inner
diameter being larger than the outer diameter of racket string 100
so that it can thread therethrough.
[0032] In addition, string engaging surface 630 of guiding groove
626, as shown in FIG. 7, has a projecting area 632 with a curved
bearing surface extending slightly into inlet 644 of guiding
channel 642 so that the diameter of inlet 644 is smaller than that
of outlet 646.
[0033] In this embodiment, device 60 is mounted on racket 90 in
such a way that cleat 64 is tightly inserted into one of string
holes 102 until that base 62 is leaned against the bottom surface
of annular channel 946 of head frame 94.
[0034] When a racket is to be equipped with stringing device 60 to
form a string opening, as shown in FIG. 7, there needs at least two
devices 60 to be mounted on two adjacent string holes 102 in such a
way that open end 628 of guiding groove 626 of each of devices 60
faces each other so that a loop 106 of string 100 connecting two
vertical strings is received over each of string engaging surface
630 of base 62 and each of two vertical strings of loop 106 is
suspended by projecting area 632 as threads through guiding channel
642 of cleat 64.
[0035] FIGS. 8 and 9 show a fourth embodiment stringing device 70
of the present invention. Device 70 is substantially the same as
device 60 described above. Device 70 differs from device 60 solely
with regard to base 72.
[0036] Base 72 has a longitudinal upper surface 722, a longitudinal
bottom surface 724 and a guiding groove 726 running longitudinally
along upper surface 722. Guiding groove 726 has a pair of opposing
longitudinal open ends 728,730 and a pair of string engaging
surface 732,734.
[0037] Device 70 also has a cleat 74 including a guiding channel
742 with an inlet 744 and an outlet 746. In this embodiment, inlet
744 is positioned between string engaging surfaces 732,734 of
guiding groove 726 of base 72. Each of string engaging surface
732,734 of guiding groove 726 has a projecting area 736, 738 with a
curved bearing surface extending slightly inwardly. This also
ensures that the diameter of inlet 744 is smaller than that of
outlet 746. The way to use device 70 is shown in FIG. 9. From this
drawing, we can have a best understanding that each of two vertical
strings connected by loop 106 will firstly be suspended by
projecting area 736 or 738, then enter into guiding channel 742
from inlet 744 and lastly threads through guiding channel 742
without touching inner wall 748 thereof. Thus, the objects or
advantages of the present invention can be achieved.
* * * * *