Patent Application
20060205525
1. Field of the Invention
This invention relates to a cue stick for playing pool or billiards and methods of making the cue stick and components thereof.
2. Description of the Prior Art
A cue stick for playing pool or billiards is typically an elongated tapered shaft with a handle at one end and a tip at the other end. The shaft and handle can be integrally formed or comprised of two or more members engaged together. Generally the cue stick is made of a hardwood such as hard maple; however, it can also be made of a non-wood material such as aluminum, stainless steel or plastic.
In order to provide optimum performance, a cue stick needs to be stiff and perfectly straight. It is also desirable for the cue stick to generate minimal vibration when striking the cue ball, and to provide a radially consistent “feel” and performance regardless of the orientation or rotation of the cue stick in the player's hand.
One problem with wood cues is that they can warp. Due to variations in moisture content, all wood expands and contracts which can lead to a bowed or warped cue stick. The warping problem has been addressed by forming the shaft using flat laminated wood rods or multiple pie-shaped wood sections. While these approaches have increased the warp resistance of wood cue sticks, there is still room for improvement.
A sleeve is generally mounted around the tip end of a cue stick to prevent splitting and wear of the tip end due to impact of the tip with the cue ball. For proper playing action, the tip end should have a high strength-to-weight ratio. In order to achieve the required strength, sleeves are typically made of ivory or reinforced plastic. Unfortunately, sleeves made of such materials are relatively heavy which can adversely affect the performance of the cue stick. For example, it has been demonstrated that a relatively low tip end mass relative to the cue ball mass helps decrease cue ball deflection when the cue ball is struck off center to impart spin.
Thus, there is a need for a cue stick and cue stick components that are highly resistant to becoming warped, generate minimal vibration and have a radially consistent feel and performance. There is also a need for a cue stick sleeve that has sufficient compression and bending strength yet is relatively light in weight.
The present invention provides an improved cue stick and cue stick components which meet the needs described above. The invention also includes methods for manufacturing the cue stick and certain components thereof.
In a first embodiment, the cue stick of this invention comprises a base shaft, a tip end piece, an inner core pin, and a sleeve. The base shaft has a first end, a second end opposed to the first end, an internal anchoring space extending through the second end, and a longitudinal cavity disposed between the first end and the second end. The longitudinal cavity is at least 12 inches in length.
The tip end piece has a lower portion extending through the second end of the base shaft into the internal anchoring space of the base shaft, an upper portion spaced from the lower portion, and a bore disposed between the lower portion and the upper portion and extending through the lower portion. The tip end piece further comprises a first end and a second end opposed to the first end. The inner core pin extends at one end through the second end of the base shaft into the internal anchoring space of the base shaft, and extends at the other end through the lower portion of the tip end piece into the bore of the tip end piece. A sleeve extends around the upper portion of the tip end piece. A cue tip is attached to the second end of the tip end piece.
The base shaft may extend the entire length of the cue stick, excluding the length of the tip end piece, in which case the base shaft includes the handle of the cue stick. Alternatively, the base shaft extends from the first end of the tip end piece for only a portion of the cue stick length, in which case a separate handle is attached to the first end of the base shaft.
One or more components of the inventive cue stick, namely the base shaft and/or handle, each comprises at least three longitudinal, rounded sections attached together. Each section has a longitudinally extending concave surface, a longitudinally extending convex surface, and an arcuate outer surface. The concave surface of each section abuts the convex surface of an adjacent section. Preferably, the, sections are formed of wood wherein the wood fiber orientation runs longitudinally and the end grain direction of each section varies from the end grain direction of adjacent sections. If the handle is formed of such construction, it may be covered by a decorative outer veneer or sleeve. As mentioned above, such a handle may be integrally formed with the base shaft or may be a separate component attached to the first end of the base shaft.
The tip end piece of the inventive cue stick is made of basswood or multiple layers of wood oriented substantially parallel to the longitudinal axis of the tip end piece. The inner core pin that extends at one end into the internal anchoring space of the base shaft, and extends at the other end through the lower portion of the tip end piece, preferably has a compressive strength of 1500 psi or greater and a specific gravity of 0.3 or less, and is preferably made of balsa wood.
The sleeve of the inventive cue stick is attached around the upper portion of the tip end piece. The sleeve preferably comprises a plurality of stacked wood layers wherein the wood cell fibers of each layer extend within the plane of the layer and each layer is oriented in a plane perpendicular to the longitudinal axis of the tip end piece. Preferably the wood cell fiber orientation of each layer varies from the fiber orientation of an adjacent layer.
In a second embodiment, the inventive cue stick comprises a base shaft, a tip end piece, and a sleeve. In this embodiment, the base shaft and sleeve are as described above. The tip end piece, however, is different. Further, this embodiment of the cue stick does not include the inner core pin. The tip end piece has a lower portion extending through the second end of the base shaft and into the internal anchoring space of the base shaft. The sleeve extends around an upper portion of the tip end piece. The tip end piece preferably comprises multiple alternating layers of a hardwood, each layer having a compressive strength of 4500 psi or greater, and another wood having a specific gravity of 0.4 or less.
A method of this invention for making a cue stick comprises the following steps. Three or more blanks are lathe-turned to form dowels having a predetermined radius. A groove is cut in each dowel wherein the groove defines an arc with a radius the same as the predetermined dowel radius, thereby producing shaped rods having a longitudinally extending concave surface and a longitudinally extending convex surface. The shaped rods are arranged such that the concave surface of each shaped rod abuts the convex surface of an adjacent shaped rod to form a substantially solid bundle having a symmetrical cross section. Each shaped rod is then affixed to an adjacent shaped rod at a contact surface defined by abutting concave and convex walls. Preferably, six shaped rods are bundled and affixed using an adhesive. The bundle is clamped using a hexagonal clamp until the glue has dried or the epoxy has cured. If desired, an axial bore is drilled through at least a portion of the bundle. The bore may be filled with a filling material or a vibration-dampening material.
A method of this invention for making a reinforcing sleeve for a cue stick comprises the following steps. A plurality of wood layers, each having a fiber orientation in the plane of the layer, are coated with an adhesive. A laminated starting block is formed by attaching a cutting pattern to one end and stacking the coated layers to a height in the range of from about one to about one and one-half inches and such that the fiber orientation of adjacent layers is misaligned. Square blanks are cut from the laminated starting block; each blank is machined to a sleeve by rounding the external surface and drilling out the center.
The features and advantages of the present invention will become readily apparent to those skilled in the art upon a reading of the following description of preferred embodiments taken in conjunction with the accompanying drawings.
A. Cue Stick
As mentioned, the cue stick of this invention has an improved resistance to warping and a radially consistent feel and performance. The cue stick has dampened vibration and includes a tip end section that has a low mass, high strength and durability, and high performance characteristics. Referring to
The base shaft 12 may extend the entire length 37 of the cue stick, excluding the tip end length, as in
Referring to
The shaft component preferably includes at least three longitudinal, rounded sections 40 attached together. More preferably six rounded sections are attached together. Each section has a longitudinally extending concave surface 42, a longitudinally extending convex surface 44, and an arcuate outer surface 46. The concave surface 42 of each section abuts the convex surface 44 of an adjacent section. Preferably, the longitudinal sections 40 are attached together with an adhesive. Examples of suitable adhesives for attaching the sections 40 together are epoxy resins, polyvinyl acetates, and polyurethane.
The longitudinal rounded sections 40 are preferably made of wood. The term “wood” as used herein and in the appended claims is defined to include naturally fibrous materials such as hardwoods and bamboo, as well as synthetic fibrous materials having properties similar to wood. Preferably wood refers to naturally fibrous materials. Examples of suitable wood include, but are not limited to, maple, oak, birch, hickory, white ash, and black cherry. More preferably, each section 40 is formed of multiple glued layers of hardwood. Most preferably, each section 40 is formed of laminated maple hardwood. When a laminated hardwood is used, preferably each layer has a thickness in the range of about 1/32 inch to about ⅛ inch. More preferably the layers have a thickness of about 1/16 inch.
The wood used to form the rounded longitudinal sections 40 comprises elongated wood cell fibers arranged in a generally uniform orientation. Preferably the wood cell fiber orientation is aligned longitudinally in each longitudinal rounded section 40. If the wood is laminated, preferably each layer is also aligned longitudinally with the section 40.
The wood used to form the longitudinal sections also has an “end grain.” The “end grain” 50 of a longitudinal section 40 is defined as the growth lines in the case of a section formed of a single piece of wood, and the glue lines in the case of a section formed of laminated wood. As used herein and in the appended claims, the “end grain direction” is defined as “the direction of the growth lines in the case of a section made from a single piece of wood, or the direction of the glue lines in the case of a section made from laminated wood.” Preferably the end grain direction of each section 40 varies from the end grain direction of adjacent sections 40. Varying the end grain direction of each section helps to achieve a more uniform radial distribution of the physical properties of the wood. Preferably, the end grain direction of each section varies by at least 10 degrees from the end grain direction of the sections adjacent thereto. More preferably, the end grain direction varies by about (360/n) degrees, where n is the number of sections used to form the base shaft or handle. For example, in a base shaft comprising three longitudinal rounded sections, as shown in
Referring now to the base shaft in
Longitudinal cavity 24 and handle cavity 24′ can be left vacant to increase flexibility of the shaft or may be filled with a filling material. For example, a filling material can be added to cavity 24 or 24′ to increase the weight of the cue stick. Preferably, cavity 24 is filled with a vibration-dampening material to reduce the vibration felt by the player due to impacting a cue ball with the cue stick. The vibration-dampening material preferably has a high surface area that diffuses reflections and attenuates the vibration as it reflects off the surface. Examples of suitable dampening materials include, but are not limited to, cork, foam, sponge, and balsa wood.
Referring now to
The tip end piece is made of a material having a low specific gravity and a compression and bend strength slightly less than that of the shaft. Examples of suitable materials include, but are not limited to, basswood, aspen, black cottonwood, and butternut.
Preferably the tip end piece is made of basswood, and more preferably it is made of multiple layers of basswood sheet or veneer wherein the layers are adhesively adjoined. The thickness of the wood layers used for the tip end piece is preferably in the range of about 1/32 inch to about ⅛ inch. As described in the discussion of the rounded longitudinal sections 40, examples of suitable adhesives include, but are not limited to, epoxy resins, polyvinyl acetates, and polyurethane.
Inner core pin 16 extends at one end 32 through the second end 22 of the base shaft, into the internal anchoring space 23 of the base shaft, and is stopped by a second shoulder 68 or end 70. The inner core pin 16 extends at the other end 34 through the lower portion 26 of the tip end piece and into the bore 30 of the tip end piece. A lower pin surface 72 is fixed to the inner surface 66 of the internal anchoring space. An upper pin surface 56 is fixed to an inner surface 60 of the tip end piece bore. Preferably the surfaces are fixed using an adhesive. Examples of suitable adhesives are the same as described above for adhering the rounded longitudinal sections 40 together.
Inner core pin 16 provides additional structural integrity and reinforces the surface adhesion of the tip end piece 14 to the base shaft 12. In order to reduce the mass of the cue stick near the end that strikes the cue ball, and still provide integrity and reinforcement, inner core pin 16 should be composed of a material that is very light but still possesses a relatively high compressive and bending strength. Preferably the inner core pin material has a compressive strength of 1500 psi or greater and a specific gravity of 0.3 or less, and more preferably is made of balsa wood.
Sleeve 18 extends around the upper portion 28 of the tip end piece. The sleeve 18 functions to prevent splitting or spreading of the end of the cue stick. Sleeve 18 has a bottom edge 74 and a top edge 76. Sleeve bottom edge 74 abuts an edge 78 of base shaft second end 22. Preferably sleeve bottom edge 74 and base shaft edge 78 are adhesively attached. Preferably an inner surface 80 of sleeve 18 is adhesively attached to outer tip end surface 64. Sleeve top edge 76 is flush with the closed end 54 of tip end piece 14.
Since it is desirable to reduce the mass of the cue stick near the end that strikes the cue ball, the sleeve 18 preferably has a specific gravity less than 1.0. More importantly, the sleeve should also have a high band strength-to-weight ratio. To maximize the band strength, the wood cell fiber orientation in the installed sleeve is preferably aligned in a plane substantially perpendicular to the longitudinal axis of the cue stick. Sleeve 18 is preferably formed from multiple laminations or veneers of wood, and more preferably from multiple laminations or veneers of a hardwood or bamboo. Suitable sleeve materials include, but are not limited to, maple, bamboo, oak, birch, hickory, white ash and black cherry.
Preferably the laminated sleeve is formed from thin hardwood layers or veneers, preferably between 0.020 inch and 0.060 inch thick, and more preferably between about 0.025 inch and 0.030 inch thick. The wood cell fibers of each layer should extend within the plane of the layer, and each layer is preferably oriented in a plane perpendicular to the longitudinal axis of the tip end piece. Preferably the wood cell fiber orientation of each layer varies from the fiber orientation of an adjacent layer; more preferably the wood cell fiber orientation of each layer varies by at least 10 degrees from the wood cell fiber orientation of an adjacent layer. Most preferably the wood cell fiber orientation of each layer varies by approximately 45 degrees from the wood cell fiber orientation of an adjacent layer.
Preferably the laminated sleeve layers are arranged such that the fiber orientation of the middle layer(s) varies from the fiber orientation of both adjacent layers, more preferably by at least 10 degrees, and most preferably by about 45 degrees from the fiber orientation of both adjacent layers as shown in
Preferably the sleeve length is in the range of about 1.0 inch to about 0.5 inch. The outer diameter 84 of the sleeve should match the outer diameter 86 of the base shaft second end 22. The thickness of the sleeve wall 88 is preferably between about 0.025 inch and 0.060 inch and is determined by the desired band strength balanced with the desired tip section weight. Sleeve wall thickness 88 then sets or determines the inner diameter 90 of the sleeve which should match inner diameter 92 of the base shaft second end.
Referring now to
A surface 106 of the lower portion 98 of the composite tip end piece is preferably adhesively attached to the inner surface 66 of the internal anchoring space. Sleeve 18 extends around the upper portion 96 of the composite tip end piece. Sleeve bottom edge 74 abuts edge 78 of base shaft second end 22. Preferably sleeve bottom edge 74 and base shaft edge 78 are adhesively attached. Preferably inner surface 80 of sleeve 18 is adhesively attached to a surface 108 of the upper portion 96 of the composite tip end piece. Sleeve top edge 76 is flush with a top end 110 of the composite tip end piece.
Composite tip end piece 94 is made by adhesively combining layers of the material described above for the tip end piece, and layers of material described for the inner core pin 16, in a manner to produce a laminate sheet. Preferably the layers are alternated and made of balsa and basswood. Preferably the wood fibers in each layer are oriented parallel to the axis of the cue stick and the layer itself is in a plane parallel to the axis of the cue stick. The thickness of each wood layer used for the composite tip end piece is preferably in the range of about 1/64 inch to about ⅛ inch. Suitable adhesives for adhesively combining the layers are the same as those described above. By alternating layers of the two materials, the combined beneficial characteristics of the tip end piece and inner core pin are maintained in a single composite tip end piece for which the manufacturing is significantly simplified.
B. Manufacture of Base Shaft and Handle
Manufacture of the base shaft and handle starts with making dowels such as the dowel 112 shown in
Dowel blanks are machined from wood or layered hardwood such that the wood fibers run longitudinally. Preferably the blank is rounded using a lathe. By turning and reducing the dowel side in multiple passes between two end points, such as on a lathe, and removing a very small amount of material in each pass, the wood is allowed to relax between passes. Thus the internal stress of the wood is relieved during the forming process. The dowel made using this procedure is much straighter and has less tendency to warp than dowels made using conventional methods.
Referring now to
To simplify the process, the grooves are preferably cut such that the end grain runs either parallel or perpendicular to a tangent at the center of the groove. For example, the end grain of each shaped rod in
The bundle 117 may be arranged leaving an axial hole 119 as shown in
Once removed from the press, the bundle is machined using a lathe to produce a smooth circular outer bundle circumference. Preferably, the outer bundle circumference is then tapered by means known to those skilled in the art to produce a base shaft 12 tapered from the first end 20 to the second end 22.
The longitudinal cavity 24 and/or 24′ is drilled from either end of the base shaft or the handle and extends the desired length. The longitudinal cavity 24 and/or 24′ may be created using a gun drill or any other technique such as is known in the art. If an axial hole 119 is formed in the bundle 117, the hole can serve as a pilot for drilling the longitudinal cavity 24.
C. Manufacture of the Sleeve
In manufacture of a laminated sleeve, a laminated starting block is first formed from thin hardwood layers or veneers, each layer having a wood fiber orientation in the plane of the layer, and each layer being preferably between 0.020 inch and 0.060 inch thick, and more preferably between about 0.025 inch and 0.030 inch thick. Each layer is coated with a thin layer of a high strength adhesive. Examples of suitable adhesives are the same as described above.
A cutting pattern 130 such as the pattern shown in
The flat press 132 shown in
Sleeves are machined making use of the cutting pattern 130 and using equipment and procedures known to those in the art. Preferably small holes are drilled using a drill press at each center mark 140 of the pattern attached to the laminated starting block. Square blanks are cut along lines 142 using, for example, a band saw; each blank is then rounded using, for example, a lathe. The small holes are then used as pilot holes to drill out the center and produce the sleeve. Preferred sleeve dimensions are as previously described.
While certain preferred embodiments of the invention have been illustrated and described for purposes of the present disclosure, numerous changes in the design and arrangement of parts and steps may be made by those skilled in the art, which changes are encompassed within the scope and spirit of the present invention as defined by the appended claims.
