The present disclosure relates to sports shafts, such as golf shafts, lacrosse shafts, hockey shafts, and baseball bats, and more particularly to vibration suppression devices for sports shafts.
The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Golf shafts are manufactured in various lengths for various different types of golf clubs. Some golf shafts are steel golf shafts, and some golf shafts are graphite golf shafts.
In golf, golf clubs are used to strike golf balls. An object is to move a golf ball from tee to a hole in a fewest number of strokes. Various types of golf clubs are used, such as woods, irons, wedges, and putters. Golf shafts include a tip end where a golf club head is attached and a butt end where a golf grip is applied.
Striking a golf ball with a golf club generates vibration within the golf shaft that may be felt by the hands, even though the golf grip. Different vibration may be felt when a golf ball is struck in a sweet spot of the golf club relative to when the golf ball is struck in another portion of the golf club, such as the heel or toe of the golf club.
Sports shafts are used to strike or move sports equipment in other sports. For example, a hockey stick is used to strike a hockey puck or ball in hockey. In baseball, baseball bats are used to strike baseballs. In lacrosse, lacrosse sticks are used to move and pass lacrosse balls. Other sports use other types of sports shafts.
Vibration experienced by hands of a user via a sports shaft may be unpleasant.
In a feature, a vibration damper to be inserted within an interior cavity of a sports shaft includes: an outer portion configured to directly contact and engage the interior cavity of the sports shaft; a central mass that extends coaxially with the outer portion and that is disposed within the outer portion; at least two arms that extend outwardly and connect the central mass to the outer portion; and at least apertures disposed between the central mass and the outer portion.
In further features, a fraction of (a) a mass of the central mass and the at least two arms divided by (b) a total mass of the vibration damper is greater than one half.
In further features, the vibration damper has a uniform mass per unit length.
In further features, the outer portion, the central mass, and the at least two arms are made of a material having a hardness between approximately 40 and 100 A-shore hardness as measured by a shore durometer.
In further features, the outer portion, the central mass, and the at least two arms are made of one of a viscoelastic material, an elastomeric material, thermoplastic polyurethane (TPU), polytetrafluoroethylene (PTFE), a rubber, a urethane poured foam, a solid foam, and a twisted braided round foam.
In further features, the outer portion forms a cylindrical tube having an outer diameter that is between approximately a 7/16 inches (1.11125 centimeters) and ½ inches (1.27 centimeters).
In further features, the vibration damper is one of extruded, molded, and three dimensionally printed.
In further features, the at least two arms include three arms that extend outwardly and connect the central mass to the outer portion.
In further features, the three arms include: a first arm that extends radially outwardly from the central mass to the outer portion; a second arm that includes a first portion that extends radially outwardly from the central mass toward the outer portion and a second portion that extends from to the first portion and to the outer portion; and a third arm that includes a third portion that extends radially outwardly from the central mass toward the outer portion and a fourth portion that extends from to the third portion and to the outer portion.
In further features, a length of the vibration damper is between approximately 0.5 and 8 inches.
In further features, a total mass of the vibration damper is between 2 and 4 grams.
In further features, at least one of the at least two arms includes a curved portion.
In further features, the at least two arms include four arms.
In further features, the four arms each include a first concave portion and a second concave portion.
In further features, the first concave portion extends radially outwardly from the central mass in one of a clockwise direction and a counterclockwise direction and the second concave portion extends outwardly in the other one of the clockwise direction and the counterclockwise direction.
In further features, an outer surface of the outer portion includes features configured to engage the interior cavity of the sports shaft.
In further features, the outer portion forms one of a squircle shaped tube, a cylindrical tube, a hexagonal tube, a rectangular tube, and an octagonal tube.
In further features, one or more sides of the outer portion are one of convex and concave.
In further features, the central mass incudes a hollow aperture through its center.
In further features, an insert is disposed within the hollow aperture.
In further features, the at least two arms each include at least one protrusion.
In a feature, a sports shaft includes: an elongated tubular portion having an inner cavity; and a vibration damper including: an outer portion configured to directly contact and engage the inner cavity of the sports shaft; a central mass that extends coaxially with the outer portion and that is disposed within the outer portion; at least two arms that extend outwardly and connect the central mass to the outer portion; and at least apertures disposed between the central mass and the outer portion.
In further features, the sports shaft is one of a golf shaft, a hockey stick shaft, a lacrosse stick shaft, and a baseball bat.
Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.
The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
In the drawings, reference numbers may be reused to identify similar and/or identical elements.
The present application involves hollow sports shafts (e.g., golf shafts, hockey stick shafts, baseball bats, lacrosse sticks, etc.) including one or more vibration damping devices (also referred to as vibration dampers and vibration suppression devices) located within the sports shafts. The vibration damping device(s) damp vibration that may otherwise be felt by one or more hands.
Each vibration damping device includes an outer portion that engages an inner portion of a sports shaft. The vibration suppression device also includes (a) a central mass and (b) two or more arms that connect the central mass to the outer portion. At least a predetermined fraction (e.g., one-half) of the total mass of the vibration suppression device lies in the central mass and the arms to maximize vibration damping. The vibration suppression device decreases vibration that could otherwise be felt by one or more hands of a user in response to contact with a sports object, such as a ball, puck, etc.
The golf shaft 104 includes a tip end 108 and a butt end 112. The outer diameter of the butt end 112 is greater than the outer diameter of the tip end 108. A golf club head can be attached to the tip end 108 of the golf shaft 104. A golf grip can be fixed at the butt end 112 of the golf shaft 104 and extend toward the tip end 108. An interior diameter of the golf shaft 104 may decrease moving from the butt end 112 toward the tip end 108.
The vibration damper 114 may have a uniform mass per unit length. The vibration damper 114 is made of a material having a hardness between approximately 40 and 100 A-shore hardness or a hardness between approximately 50 and 90 A-shore hardness as measured by a shore durometer. Having a hardness within these ranges may provide more desirable vibration damping characteristics than other hardnesses. The material may be, for example, a viscoelastic material, an elastomeric material, thermoplastic polyurethane (TPU), polytetrafluoroethylene (PTFE), a rubber, a urethane poured foam, a solid (e.g. open or closed cell) foam, a twisted braided round foam (e.g., 0.25 inch) or another suitable material within the hardness ranges provided above.
An inserting rod 120 may be used to insert the vibration damper 114 into the golf shaft 104. The inserting rod 120 may be moved linearly approximately coaxially with the golf shaft 104 into the hollow interior of the golf shaft 104 to push the vibration damper 114 to a predetermined location within the interior of the golf shaft 104. The predetermined location is between the tip end 108 and a location where a golf grip will end. More generally speaking, the predetermined location is between the tip end 108 and where hands are intended to be placed on the golf shaft 104.
For example only, the inserting rod 120 may apply at least approximately 200 pounds of force (approximately 889 Newtons) to the vibration damper 114 while the golf shaft 104 is held stationary to insert the vibration damper 114 into the golf shaft 104. The force applied to the vibration damper 114, however, may be greater than or less than 200 pounds. A linear actuator may linearly actuate the inserting rod 120 into the golf shaft 104 to insert the vibration damper 114. In various implementations, the inserting rod 120 may be inserted manually by a human.
The insertion of the vibration damper 114 may create an interference fit between the vibration damper 114 and the interior of the golf shaft 104. A vibration damper is added to each golf shaft to damp vibration of that golf shaft.
In the example of a golf shaft, the vibration damper 114 may have, for example, a 7/16″ (1.11125 centimeter) outer diameter, a ½″ (1.27 centimeter) outer diameter, an outer diameter between approximately 7/16″ and approximately ½″, or another suitable outer diameter. The outer diameter of the vibration damper 114 may be greater than an inner diameter at a predetermined location, such as a location ⅔ of the way from the butt end 112 to the tip end 108. The outer diameter of the vibration damper 114 being greater than the inner diameter of the golf shaft 104 may cause the vibration damper 114 to deform slightly during insertion into golf shaft yet not plug the golf shaft. Plugging of a golf shaft (as may occur if solid/non-hollow vibration dampers were used) may make securing a golf club head and/or a grip to the golf shaft difficult and non-optimal. Plugging may also trap water within a golf shaft.
As discussed above, the vibration damper 114 may be held within the golf shaft 104 via an interference fit. Additionally or alternatively, the golf shaft 104 may be subjected to one or more heat treatments for one or more predetermined periods, respectively. For example, the golf shaft 104 may be heated (e.g., by a furnace) to a predetermined temperature that is less than or equal to the melting point temperature of the vibration damper 114 for a predetermined period. In various implementations, the predetermined temperature may be greater than the melting point temperature of the insert. In such an implementation, the predetermined period may be set low enough to allow for melting of an exterior portion skin of the vibration damper 114 while preventing melting of the remainder of the vibration damper 114.
The heating of the golf shaft 104 and the vibration damper 114 may adhere the vibration damper 114 to the interior surface of the golf shaft 104 and increases a force necessary to remove the vibration damper 114 from the golf shaft 104. In various implementations, the vibration damper 114 may be fixed within the golf shaft 104 via an adhesive between the outer surface of the vibration damper 114 and the inner surface of the golf shaft 104. In various implementations, double-sided tape may be disposed between the outer surface of the vibration damper 114 and the inner surface of the golf shaft 104 to fix the vibration damper 114 within the golf shaft 104. The vibration damper 114 may be fixed in another suitable manner.
For example, golf shafts have a hollow circular inner shape. As the inner portion of a golf shaft may be tapered, the inner portion of the golf shaft may be frustoconical. In various implementations, the inner portion of golf shafts may be non-tapered and cylindrical. As shown in
The vibration damper 114 also includes a central portion 308 that is connected to the circular outer portion 304. The central portion 308 may be a solid cylindrical member or have another suitable shape. The central portion 308 is connected to the circular outer portion 304 via two or more arms, such as arms 312. The arms 312 extend outwardly (e.g., radially outwardly) from the central portion 308 to the circular outer portion 304 in the example of
A thickness of the circular outer portion 304 may be minimized (e.g., less than a predetermined thickness) to maximize a mass of the vibration damper 114 attributable to the arms 312 and the central portion 308. Maximizing a mass of the arms 312 and the central portion 308 increases the damping provided by the vibration damper 114.
In the example of
The first portions 516 do not extend to the circular outer portion 304. Example dimensions (in inches) for the vibration damper 114 are provided in
While example dimensions are provided, the present application is also applicable to other dimensions. For example, thicknesses of the arms and the circular outer portion of the vibration damper 114 may be between 0.02 and 0.04 inches in various implementations. A fraction of (a) a mass of the central portion 308 and the arms divided by (b) a total mass of the vibration damper 114 (the mass of the central portion 308, the arms, and the circular outer portion) may be greater than a predetermined fraction to maximize vibration damping. The predetermined fraction is greater than zero and may be, for example, greater than ½ (50%), approximately ⅗ (60%), approximately ¾ (75%), or another suitable fraction less than 1. Approximately may mean+/−10%. The total mass of the vibration damper 114 may be between 2 and 4 grams, such as to minimize the total mass of the golf shaft 104.
Other example implementations of the vibration damper 114 for golf shafts and baseball bats are provided in
The handle portion 12 can be elongated, hollow, and longitudinally straight. In some embodiments, the handle portion 12 can include a hollow core that is embedded and wrapped within a covering (e.g., composite material with carbon fibers).
Referring back to
The blade portion 16 generally includes a front face 20, which can be used for receiving and moving the hockey puck 18 (e.g., passing, shooting, stopping, etc.), and a rear face 22, which can also be used for receiving and moving the hockey puck 18.
The blade portion 16 also includes a first end 28 that is connected to the blade connecting end 13 of the handle portion 12. The blade portion 16 also includes a second end 30 that is opposite to the first end 28.
The blade portion 16 also includes an upper edge 24 and a lower edge 26 that is opposite the upper edge 24. The upper edge 24 is typically spaced away from a playing surface (e.g., ice). The lower edge 26 may contact the playing surface.
Both the upper and lower edges 24 and 26 extend between the first and second ends 28 and 30 of the blade portion 16. The upper and lower edges 24 and 26 and the front and rear faces 20 and 22 can have a curvature between the first and second ends 28 and 30 such that the front face 20 is concave while the rear face 22 is convex or vice versa. In various implementations, such as in the example of a goalie stick, the blade portion 16 may be flat.
As shown in
The vibration damper 114 of the handle portion 12 includes an outer portion 1104. The outer portion 1104 may form a hollow rectangular tube. Two or both sets of opposite sides of the outer portion 1104 may be convex as illustrated. The outer portion 1104 may have the same geometry/shape as an inner portion (interior walls) of the handle portion 12.
The vibration damper 114 also includes a central portion 1108 that is connected to the outer portion 1104. The central portion 1108 may be a solid cylindrical member or have another suitable shape. The central portion 1108 is connected to the outer portion 1104 via two or more arms, such as arms 1112. The arms 1112 extend radially outwardly from the central portion 1108 to the circular outer portion 1104. The arms 1112 may be straight or include one or more radially outward portions (masses), such as 1116 and/or 1120. The radially outward portions 1116 and/or 1120 may further damp vibration. The radially outward portions 1116 and 1120 have at least one dimension (e.g., a thickness) that is greater than the other portions of the arms 1112.
A thickness of the outer portion 1104 may be minimized to maximize a mass of the vibration damper 114 attributable to the arms 1112 and the central portion 1108. Maximizing a mass of the arms 1112 and the central portion 1108 increases damping of the vibration damper 114. While the example of two arms is provided, as discussed above, the vibration damper 114 may include more than two arms.
Example dimensions (in inches) for the vibration damper 114 are provided in
While example dimensions are provided, the present application is also applicable to other dimensions. For example, thicknesses of the arms and the outer portion of the vibration damper 114 may be between 0.02 and 0.04 inches in various implementations. A fraction of (a) a mass of the central portion 1108 and the arms divided by (b) a total mass of the vibration damper 114 (the mass of the central portion 308, the arms, and the circular outer portion) may be greater than the predetermined fraction to maximize vibration damping.
The vibration damper 114 may be fixed within the handle portion 12 of the hockey stick via an interference fit, via an adhesive, via double-sided tape, or in another suitable manner. The vibration damper 114 may be fixed within the handle portion 12, for example, before the blade portion 16 is connected to the handle portion 12.
As another example, the vibration damper 114 may be implemented within a lacrosse stick.
The vibration damper 114 of the handle portion 1408 includes an outer portion 1604. The outer portion 1604 may form a hollow hexagonal tube. One or more pairs of opposite sides of the outer portion 1604 may be concave, convex, or a combination of concave and convex. The outer portion 1604 may have the same geometry/shape as an inner portion (interior walls) of the handle portion 1408.
The vibration damper 114 also includes a central portion 1608 that is connected to the outer portion 1604. The central portion 1608 may be a solid cylindrical member or have another suitable shape. The central portion 1608 is connected to the outer portion 1604 via two or more arms, such as arms 1612. The arms 1612 extend radially outwardly from the central portion 1608 to the outer portion 1604. The arms 1612 may be straight or include one or more radially outward portions, such as in the example of
A thickness of the outer portion 1604 may be minimized to maximize a mass of the vibration damper 114 attributable to the arms 1612 and the central portion 1608. Maximizing a mass of the arms 1612 and the central portion 1608 increases damping of the vibration damper 114. While the example of four arms is provided, as discussed above, the vibration damper 114 may include two or more arms.
The vibration damper 114 may have a length of between approximately 0.5 inches and approximately 8 inches. Thicknesses of the arms and the outer portion of the vibration damper 114 may be between 0.02 and 0.04 inches in various implementations. A fraction of (a) a mass of the central portion 1608 and the arms divided by (b) a total mass of the vibration damper 114 (the mass of the central portion 1608, the arms, and the circular outer portion) may be greater than the predetermined fraction to maximize vibration damping.
The vibration damper 114 may be centered a predetermined distance (e.g., approximately 2 to 8 inches) from the end of the handle portion 1408 where the handle portion 1408 connects to the head portion 1412.
The vibration damper 114 may be fixed within the handle portion 1408 of the lacrosse stick via an interference fit, via an adhesive, via double-sided tape, or in another suitable manner.
As another example, the vibration damper 114 may be implemented within a baseball bat.
The handle portion 1708 where the vibration damper 114 is fixed may be a hollow frustoconical tube or a hollow cylindrical tube.
The vibration damper 114 includes a circular outer portion 1804. The outer portion 1804 may form a hollow cylindrical tube (as shown in
The vibration damper 114 also includes a central portion 1808 that is connected to the outer portion 1804. The central portion 1808 may be a solid cylindrical member or have another suitable shape. The central portion 1808 is connected to the outer portion 1804 via two or more arms, such as arms 1812. The arms 1812 extend radially outwardly from the central portion 1808 to the outer portion 1804. The arms 1812 may be straight or include one or more radially outward portions, such as in the example of
A thickness of the outer portion 1804 may be minimized to maximize a mass of the vibration damper 114 attributable to the arms 1812 and the central portion 1808. Maximizing a mass of the arms 1812 and the central portion 1808 increases damping of the vibration damper 114. While the example of three arms is provided, as discussed above, the vibration damper 114 may include two or more arms.
The vibration damper 114 may have a length of between approximately 0.5 inches and approximately 8 inches. Thicknesses of the arms and the outer portion of the vibration damper 114 may be between 0.02 and 0.04 inches in various implementations. A fraction of (a) a mass of the central portion 1108 and the arms divided by (b) a total mass of the vibration damper 114 (the mass of the central portion 1808, the arms, and the circular outer portion) may be greater than the predetermined fraction to maximize vibration damping.
The vibration damper 114 may be centered a predetermined distance (e.g., approximately 2 to 8 inches) from the end of the handle portion 1708 where the handle portion 1708 connects to the head or barrel portion 1712. Generally speaking, all of the vibration dampers 114 may be fixed within the respective shafts or handle portions between where impact occurs and where one or more hands of a user usually touch the shaft or handle portion
The vibration damper 114 may be fixed within the handle portion 1708 of the bat via an interference fit, via an adhesive, via double-sided tape, or in another suitable manner.
The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented in and/or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with one another remain within the scope of this disclosure.
Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”
This application claims the benefit of U.S. Provisional Application No. 63/187,578, filed on May 12, 2021. The entire disclosure of the application referenced above is incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/US2022/027223 | 5/2/2022 | WO |
Number | Date | Country | |
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63187578 | May 2021 | US |