U.S. patent application number 11/871010 was filed with the patent office on 2009-02-19 for shaft of cue sticks.
Invention is credited to Jung-Shih CHANG.
Application Number | 20090048032 11/871010 |
Document ID | / |
Family ID | 40060331 |
Filed Date | 2009-02-19 |
United States Patent
Application |
20090048032 |
Kind Code |
A1 |
CHANG; Jung-Shih |
February 19, 2009 |
SHAFT OF CUE STICKS
Abstract
A shaft of a cue stick for billiards or pool, includes an
elongated tapered body laminated of a plurality of wood strips,
each of the wood strips in cross-section having a sector section
with an arcuate outer surface and an arc inner notch such that when
the wood strips are laminated together, the arcuate outer surfaces
form an outer surface of the body and the inner notches define an
axial hole through the body; and a circular core tube made of a
material having a greater rigidity than wood and having a shorter
length than the axial hole, the tube being firmly received in the
axial hole in such a way that the cue sticks body has a front
hollow section extending a predetermined length along its axis from
larger diameter to the smaller diameter end.
Inventors: |
CHANG; Jung-Shih; (Taichung
Hsien, TW) |
Correspondence
Address: |
BROWDY AND NEIMARK, P.L.L.C.;624 NINTH STREET, NW
SUITE 300
WASHINGTON
DC
20001-5303
US
|
Family ID: |
40060331 |
Appl. No.: |
11/871010 |
Filed: |
October 11, 2007 |
Current U.S.
Class: |
473/44 ;
473/520 |
Current CPC
Class: |
A63D 15/08 20130101 |
Class at
Publication: |
473/44 ;
473/520 |
International
Class: |
A63D 15/08 20060101
A63D015/08 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 13, 2007 |
TW |
200720127180.5 |
Claims
1. A shaft which forms a separable length of a cue stick for
playing billiard or pool game, comprising: an elongated body
tapering from a first end to a second end, said first end having a
smaller diameter than said second end; said body laminated of a
plurality of at least four wood strips, each of said wood strips in
cross-section thereof including a sector section having an arcuate
outer surface and an arc inner notch such that when said wood
strips are laminated, said arcuate outer surfaces thereof form an
outer surface of said body and said inner notches thereof define an
axial cylindrical hole of said body; and a circular core tube made
of a material having a larger rigidity than wood and having a
shorter length than said axial hole, said tube being firmly
received in said axial hole of said body in such a way that said
body has an empty front hollow section extending a predetermined
length along the axis of said body from said first end of said body
to a first adjacent end of said core tube.
2. The shaft as claimed in claim 1, wherein said core tube is made
of fiber-reinforced plastic materials.
3. The shaft as claimed in claim 1, wherein said body has an empty
rear hollow section with a predetermined length along the axis of
said body from said second end of said body to a second adjacent
end of said core tube.
4. The shaft as claimed in claim 1, wherein the length of said core
tube is equal to one half of the length of said body.
5. The shaft as claimed in claim 1, wherein the number of said wood
strips is four, each of said wood strips in cross-section thereof
is a ninety degree sector section.
6. The shaft as claimed in claim 1, wherein the number of said wood
strips is six, each of said wood strips in cross-section thereof is
a sixty degree sector section.
7. The shaft as claimed in claim 1, wherein the number of said wood
strips is eight, each of said wood strips in cross-section thereof
is a forty-five degree sector section.
8. The shaft as claimed in claim 1, wherein the diameter of said
first end of said body is in the range of 12.5 mm to 13 mm.
9. The shaft as claimed in claim 8, wherein the diameter of said
axial hole of said body is about 6 mm.
10. The shaft as claimed in claim 9, wherein the outer diameter of
said core tube is about 6 mm.
11. The shaft as claimed in claim 10, wherein the inner diameter of
said core tube is about 4 mm.
12. The shaft as claimed in claim 1, wherein the length of said
body is about 740 mm.
13. The shaft as claimed in claim 12, wherein the length of said
core tube is about 380 mm.
14. The shaft as claimed in claim 13, wherein the length of said
front hollow section is about 180 mm.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to cue sticks for playing
billiard or pool and, more particularly, to an improved shaft of a
cue stick.
[0003] 2. Description of the Related Art
[0004] A prior art billiard cue disclosed in U.S. Pat. No.
1,702,292 has a body portion formed of a plurality of longitudinal
wood sections secured together and a hollow metallic reinforcing
core received within the body and extending throughout the length
of the body. Although maintaining the cue against warping or
becoming distorted, the improvement is followed by a drawback that
the flexibility of the impact end of the cue is decreased. As a
result, when the cue is lined up to strike the cue ball off center,
the cue ball striked does not follow a path of movement that is
parallel to the line of stroke of the cue.
[0005] For eliminating the drawback mentioned above, U.S. Pat. No.
5,725,437 discloses an improved billiard cue having a ferrule with
a bore, and a wood shaft with a tenon inserting into the bore in
such a way that a hollow portion is formed in the impact end of the
shaft to absorb part of the impact forces imposing thereon. As a
result, the inward buckling of the impact end of the shaft on off
center hits is decreased so that the cue ball hit can follow a path
of movement that is parallel to the line of stroke of the cue.
[0006] However, for having a wood shaft, this improved cue provides
a poor radial consistency. Speaking detailedly, the meaning of
"radial consistency" is that when a player uses each of contact
points defined by the same radius of the hitting surface of a cue
tip mounted on a shaft to hit a cue ball in the same way, such as
the same hitting angle, the same hitting force, etc., the cue ball
hit, in each hitting, should have the same response.
[0007] Due to the fact that the grain and density of wood materials
are non-homogeneous, the center of gravity of a wood shaft does not
locate on the axis thereof. As a result, when a player uses a prior
art wood shaft to hit a cue ball in the same way but with different
contact points defined by the same radius of the hitting surface of
a cue tip mounted on the wood shaft, the cue ball hit, in each
hitting, would have different response.
[0008] U.S. Pat. No. 6,869,370 suggests an approach to improve
"radial consistency" of a wood shaft of a billiard cue. The
approach is to provide a wood shaft laminated by a central
elongated wood member and a plurality of surrounding wood elongated
members. For having a wood elongated central member, such a
laminated wood shaft could have a center of gravity located on the
axis thereof. Thus, "radial consistency" of the laminated wood can
be improved.
[0009] However, it had been found that, in practical using, "radial
consistency" of the laminated wood shaft mentioned above could not
be improved effectively. The primary reason is that the wood
elongated central member is not rigid enough to resist averagely
the outer compressing force coming from omnidirection during
laminating processes so that the center of gravity of the laminated
wood shaft would be shifted from the axis thereof alter laminating
processes.
[0010] Thus, it would be desirable to provide an improved shaft of
a cue stick of which the inward buckling of the impact end on off
center hits is minimized and, in the same time, the center of
gravity is exactly located on the axis thereof.
SUMMARY OF THE INVENTION
[0011] To achieve the desire, the present invention discloses an
improved shaft of a cue stick which comprises an elongated body
tapering from a first end to a second end. The body is laminated of
a plurality of wood strips. Each of the wood strips in
cross-section thereof includes a sector section having an arcuate
outer surface and an arc inner notch. The wood strips are laminated
in such a way that after laminating, the arcuate outer surfaces
thereof form an outer surface of the body and the inner notches
thereof define an axial hole of the body. The shaft further
comprises a circular core tube made of materials having a larger
rigidity than wood materials. The tube is shorter than the axial
hole of the body and firmly received therein in such a way that the
body forms a front hollow section extending a predetermined length
along the axis thereof from the first end thereof to the second end
thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The foregoing and others features of the present invention
will become more apparent by referring to the following detailed
description and drawing in which:
[0013] FIG. 1 is a side elevational view of a cue stick with a
first preferred embodiment of a shaft constructed in accordance of
the teachings of the present invention;
[0014] FIG. 2 is a cross sectional view generally taken along line
2-2 in FIG. 1;
[0015] FIG. 3 is a cross sectional view generally taken along line
3-3 in FIG. 2;
[0016] FIG. 4 is a cross sectional view generally taken along line
4-4 in FIG. 2;
[0017] FIG. 5 is similar to FIG. 4 but showing a cross sectional
view of a second preferred embodiment of a shaft constructed in
accordance of the teachings of the present invention; and
[0018] FIG. 6 is similar to FIG. 4 but showing a cross sectional
view of a third preferred embodiment of a shaft constructed in
accordance of the teachings of the present invention.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0019] Referring now to the drawings, FIG. 1 is a side elevational
view of a cue stick 10 including a shaft 12 constructed in
accordance of the teachings of the present invention, a butt 14
coaxially threadingly joined to shaft 12, a butt pad 16 attached to
a free end of butt 14.
[0020] Body 18 is about 740 mm in length and laminated of a
plurality of elongated wood strips 30. In this embodiment, body 18
is laminated of four elongated wood strips 30. Each of elongated
wood strips 30 in cross-section has a ninety degree section with an
arcuate outer surface 32 and an inner notch 34 (as shown in FIG.
3). Elongated wood strips 30 are laminated in such a way that after
laminating, arcuate outer surfaces 32 form an outer surface of body
18 and inner notches 34 defines an axial hole 36 of body 18. For
achieving a better performance, the diameter of first end 22 of
body 18 is designed in the range of 12.5 nm to 13 mm. The diameter
of second end 24 of body is about 20 mm. The diameter of axial hole
is about 6 mm.
[0021] Of course, body 18 can be assembled by six or eight
elongated wood strips 30', 30'' and each of elongated wooden
members 30', 30'' in cross-section has a ninety or forty-five
degree section (as shown in FIGS. 5 and 6).
[0022] Core tube 20 is made of materials having a larger rigidity
than wood, such as fiber-reinforced plastics, metal, etc. and
having a shorter length than axial hole 36 of body 18. To get a
better performance, as body 18 has the size mentioned above, core
tube 20 should be sized in such a way that it is about 380 mm in
length, 6 mm in outer diameter, and 4 mm in inner diameter. In
combination, core tube 20 is firmly received in axial hole 36 of
body 18 in such a way that body 18 forms a front hollow section 40
extending a predetermined length along the axis thereof from First
end 22 thereof to second end 24 thereof. In this embodiment, core
tube 20 is received in the center portion of axial hole 36 so that
front hollow section 40 is 180 mm in length and in the same time a
rear hollow section 42, 180 mm in length, is defined.
[0023] As disclosed above, it can be found that for a shaft
constructed according to the teaching of the present invention has
a body laminated of a plurality of elongated wood strips and a
rigid core tube having a specific length and received in the center
portion of the axial hole of the body, the core tube, when
laminated with the wood strips, would work as a rigid compressed
center to resist averagely the outer compressing force coming from
omnidirection during laminating processes. As a result, the center
of gravity of the shaft would be exactly located in the axis
thereof after laminating processes. In other words, the shaft
disclosed in the present invention can provide a better "radial
consistency".
[0024] In addition, for having a front hollow section, the impact
end of the shaft constructed according to the teaching of the
present invention has a minimized inward buckling on off center
hits. Thus, the cue ball hit by the shaft would follow a path of
movement that is parallel to the line of stroke of the shaft.
[0025] Moreover, the shaft constructed according to the teaching of
the present invention not only has a front hollow section but a
rear follow section so that the weight thereof is effectively
decreased.
* * * * *