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.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to cue sticks for playing billiard or pool and, more particularly, to an improved shaft of a cue stick.

2. Description of the Related Art

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.

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.

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.

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.

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.

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.

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

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

The foregoing and others features of the present invention will become more apparent by referring to the following detailed description and drawing in which:

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;

FIG. 2 is a cross sectional view generally taken along line 2-2 in FIG. 1;

FIG. 3 is a cross sectional view generally taken along line 3-3 in FIG. 2;

FIG. 4 is a cross sectional view generally taken along line 4-4 in FIG. 2;

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

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

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.

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.

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).

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.

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”.

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.

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.

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; anda 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.