Title:
Multilayer impact resistant hockey stick
Kind Code:
A1


Abstract:
A multilayer hockey stick is provided having improved impact resistant and energy absorbing characteristics. The hockey stick includes a shaft having a body, an energy absorbing layer and an impact resistant layer. The energy absorbing layer and impact resistant layer are applied to select areas of the shaft of the hockey stick which are prone to failure due to stick-to-stick contact.



Inventors:
Horwood, Graeme (Germantown, TN, US)
Hedrick, Michael (Vyhalia, MS, US)
Application Number:
09/760018
Publication Date:
07/18/2002
Filing Date:
01/12/2001
Assignee:
HORWOOD GRAEME
HEDRICK MICHAEL
Primary Class:
International Classes:
A63B59/14; A63B59/00; (IPC1-7): A63B59/12; A63B59/14
View Patent Images:
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Primary Examiner:
GRAHAM, MARK S
Attorney, Agent or Firm:
Christopher M. Brock (Bloomfield Hills, MI, US)
Claims:

What is claimed is:



1. An apparatus for playing sports having a shaft-like portion, said shaft-like portion comprising: a body; an energy absorbing layer disposed adjacent to said body; and an impact resistant layer disposed adjacent to said energy absorbing layer.

2. The apparatus for playing sports according to claim 1, wherein said body is selected from the group consisting of wood, composite, metals, fiberglass, plastic, KEVLAR®, carbon and combinations thereof.

3. The apparatus according to claim 1, wherein said energy absorbing layer further comprises a viscoelastic layer.

4. The apparatus according to claim 3, wherein said viscoelastic layer further comprises a viscoelastic tape disposed about said body.

5. The apparatus according to claim 4, wherein said impact resistant layer further comprises a polycarbonate material.

6. The apparatus according to claim 5, wherein said impact resistant layer further comprises a polycarbonate sleeve disposed over said body.

7. The apparatus of claim 6, wherein said polycarbonate sleeve includes corners having more polycarbonate material than between said corners.

8. The apparatus according to claim 1, wherein said body further comprises a recessed portion accommodating at least one of said energy absorbing layer and said impact resistant layer.

9. The apparatus according to claim 8, wherein said recessed portion extends annularly around said body.

10. The apparatus according to claim 8, wherein a depth of said recessed portion is substantially equal to a thickness of the energy absorbing layer and the impact resistant layer.

11. The apparatus according to claim 8, wherein said impact resistant layer is substantially coplanar with an external surface of said body.

12. A hockey stick comprising: a shaft having a first end and a second end; and a blade adjacent said first end of said shaft; wherein said shaft of said hockey stick includes a body and an impact resistant layer coupled to body.

13. The hockey stick according to claim 12 further comprising an energy absorbing layer disposed between said body and said impact resistant layer.

14. The hockey stick according to claim 13 wherein said energy absorbing layer substantially encircles said body of said shaft.

15. The hockey stick according to claim 14 wherein said impact resistant layer substantially encircles said energy absorbing layer.

16. The hockey stick according to claim 15 wherein said impact resistant layer further comprises a polycarbonate layer.

17. The hockey stick according to claim 16 wherein said energy absorbing layer further comprises a viscoelastic layer.

18. The hockey stick according to claim 13 wherein said impact resistant layer and said energy absorbing layer are disposed adjacent a lower portion of said shaft proximate said first end.

19. The hockey stick according to claim 13 wherein said impact resistant layer and said energy absorbing layer are disposed adjacent an upper portion of said shaft proximate said second end.

20. The hockey stick according to claim 13, wherein said impact resistant layer and said energy absorbing layer are disposed substantially along said shaft between said first end and said second end.

21. A method of preparing a shaft comprising the steps of: providing a shaft body; securing an energy absorbing layer to said body; and securing an impact resistant layer to said energy absorbing layer.

22. The method according to claim 21 wherein said step of securing said energy absorbing layer to said body further comprises wrapping an energy absorbing tape around said body.

23. The method according to claim 22 wherein said step of wrapping said energy absorbing layer around said body further comprises wrapping a viscoelastic layer around said body.

24. The method according to claim 23, wherein said viscoelastic layer has a width substantially the same as a circumference of the shaft body.

25. The method according to claim 24 wherein said step of securing said impact resistant layer to said energy absorbing layer further comprises disposing an impact resistant sleeve over said energy absorbing layer.

26. The method according to claim 25 wherein said step of disposing said impact resistant sleeve over said energy absorbing layer further comprises snapping said impact resistant sleeve over said shaft body via a longitudinal slot formed in said impact resistant sleeve.

27. The method according to claim 25 wherein said step of disposing said impact resistant sleeve over said energy absorbing layer further comprises telescopically sliding said impact resistant sleeve over said shaft body.

Description:

FIELD OF THE INVENTION

[0001] The present invention relates generally to hockey sticks, and more particularly to a hockey stick having improved impact resistance and energy absorbing characteristics.

BACKGROUND OF THE INVENTION

[0002] The popularity of sporting events in today's society has prompted a wide movement in the development of sports equipment. In most sporting events there is a need to develop equipment that exhibits maximum performance while minimizing production costs. One way of altering the development of equipment lies in the selection of materials used to manufacture the equipment. The combination of materials used to design a variety of sports equipment continues to provide advancements in the technology.

[0003] One particular aspect of sports equipment design is focused on strengthening particular structural components of the equipment. This type of development may be applied to a variety of sporting events which utilize shafts such as bats, rackets, and sticks. For example, such shafts are utilized in hockey, baseball, lacrosse, and tennis, among others.

[0004] Hockey is one sport in which equipment design has continued to develop. Although the functionality of a hockey stick has remained constant over time, the design and manufacture of hockey sticks has continued to progress and change due to the variety of materials now being used in the industry. Materials used in the manufacturing of hockey sticks are modified not only due to the desired physical characteristics of the hockey sticks, but various performance characteristics as well.

[0005] A hockey stick must be lightweight and have a strength substantial enough to endure the stresses that occur during use. More particularly, the hockey stick should be able to endure the primary stresses that develop in the shaft of the hockey stick, especially the maximum stress that occurs towards the shaft/blade interface when sticks come into contact in play. The flexibility of a hockey stick is an additional performance characteristic that is desirable, due to the importance of the hockey stick having the ability to provide enough “flex” during wrist shots and slap shots for the user to maximize shot velocity and control.

[0006] Hockey sticks can be made from a variety of materials, including wood, aluminum, plastic, fiberglass, carbon, KEVLAR®, or combinations thereof. Traditionally, the selection of materials is primarily based on the weight, stiffness and cost of each of the materials. Composite shafts are somewhat expensive and have poor durability, but are still popular primarily due to their light weight. Wood shafts are relatively inexpensive, however, they are not especially lightweight, stiff or durable. Aluminum shafts are somewhat less reliable due to the fact that bending failures frequently occur within the shaft.

[0007] In view of the foregoing, it can be appreciated that there is a continuing need to develop hockey sticks which are inexpensive, lightweight, durable, impact resistant, and flexible. As the popularity of hockey continues, the technology of the equipment must continue to develop as well.

SUMMARY OF THE INVENTION

[0008] One object of the present invention is to provide a shaft and a method for making the same which has a reinforced section that exhibits increased durability and strength.

[0009] Another object of the present invention is to provide a shaft and method for making the same which has a reinforced section that includes an energy absorbing layer and an impact resistant layer.

[0010] In particular, one aspect of the present invention provides a hockey stick and method of making the same that includes a shaft having a body, an energy absorbing layer and an impact resistant layer. The energy absorbing layer and impact resistant layer are applied to select areas of the shaft of the hockey stick which benefit from reinforcement or are prone to damage due to use.

[0011] Another aspect of the present invention improves durability of lightweight hockey sticks, while at the same time maintaining the rectangular geometry of the stick. This is obtained by wrapping an energy absorbing layer around the body of the shaft and snapping or sliding an impact resistant sleeve around the energy absorption material and shaft body.

[0012] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood however that the detailed description and specific examples, while indicating preferred embodiments of the invention, are intended for purposes of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The various advantages of the present invention will become apparent to one skilled in the art by reading the following specification and subjoined claims and by referencing the following drawings in which:

[0014] FIG. 1 is a perspective view of a preferred embodiment of a hockey stick of the present invention having a reinforced portion of the shaft;

[0015] FIG. 2 is a cross-sectional view taken along section line 2-2 of FIG.

[0016] FIG. 3a is a longitudinal cross-sectional view of the preferred embodiment of a hockey stick of the present invention 1;

[0017] FIG. 3b is a longitudinal cross-sectional view of an alternate embodiment of a hockey stick of the present invention;

[0018] FIG. 3c is a longitudinal cross-sectional view of another alternate embodiment of a hockey stick of the present invention;

[0019] FIG. 4a is a perspective view of the present invention demonstrating a method of applying the energy absorbing layer to the shaft body of the hockey stick;

[0020] FIG. 4b is an exploded view showing the relation of the impact resistant layer to the shaft body wrapped with the energy absorbing layer;

[0021] FIG. 4c is a perspective view of the present invention having the impact resistant layer outboard of the energy absorbing layer of the shaft body;

[0022] FIG. 5 is an exploded view of a circumferentially enclosed polycarbonate sleeve positioned to be telescopically received by the shaft body;

[0023] FIG. 6 is a cross-sectional view of yet another alternate embodiment of the present invention; and

[0024] FIG. 7 is a perspective view of still yet another alternate embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Referring first to FIG. 1, a hockey stick 10 is divided into three areas; a blade 12, a shaft 14 and an end plug 16. It is within each of these structural areas of the hockey stick 10 that various improvements are implemented in order to enhance the performance characteristics of the hockey stick 10. The present invention focuses primarily on the shaft 14 of the hockey stick 10 and certain modifications therein.

[0026] In general, the shaft 14 of the hockey stick 10 has a first end 18 opposite a second end 20. The first end 18 of the shaft 14 is found where the shaft 14 is coupled with the blade 12 of the hockey stick 10. The second end 20 of the shaft 14 is found where the shaft 14 transitions to the end plug 16. Many of the stresses that occur to a hockey stick during use occur at locations proximate to where the blade 12 and the shaft 14 meet. Stress regions are exhibited along the shaft 14 due to the large amount of stick-to-stick and stick-to-ice contact occurring during usage. One particular high stress region, known as the slash zone, is located proximate the first end 18 of the shaft 14. More specifically, the slash zone is located within the lower portion 22 of the shaft 14. Although high stress regions primarily occur in the lower portion 22 of the shaft, occasional stress areas may occur within the upper portion 24 of the shaft 14 proximate the second end 20 due to player to player contact.

[0027] In order to improve the durability and impact resistance of the hockey stick 10 at various stress regions along the shaft 14, it is desirable to apply supplemental layers.

[0028] As can be seen in FIG. 2, which is a cross-sectional view of the shaft 14 of hockey stick 10 taken along lines 2-2 of FIG. 1, a plurality of reinforcing layers surround the shaft 14. The shaft 14 includes a body 26 longitudinally extending the entire length of the shaft 14. The body 26 of hockey stick 10 can be comprised of various materials, which may include but are not limited to wood, composite, various metals, fiberglass, plastic, KEVLAR®, carbon and combinations thereof.

[0029] An energy absorbing layer 28 is disposed on the outer surface of the body 26. The energy absorbing layer 28 is a cushioning material which provides an energy absorption medium along prescribed regions of the shaft 14. The energy absorbing layer 28 is preferably made of a viscoelastic material which may include but is not limited to a variety of viscoelastic damping polymers, such as VHB®, Sorbothane®, T-lastic®, etc. The energy absorbing layer 28 is preferably approximately 0.015 inches to 0.025 inches thick. Although this particular thickness is generally preferred, the thickness of the energy absorbing layer 28 may be varied according to the particular stresses expected to be endured.

[0030] The preferred embodiment of the present invention employs 3M's VHB® tape as the energy absorbing layer. The VHB® tape is a double-sided viscoelastic tape 28a having an acrylic adhesive 29a, 29b on each side. The acrylic adhesive is an aggressive adhesive which secures the energy absorbing layer 28 to the body of the shaft. Although VHB® tape is currently being used, alternate types of energy absorbing material may be used in combination with various adhesives, if desired.

[0031] The outer perimeter of the shaft 14 is enclosed by an impact resistant layer 30. The impact resistant layer 30 preferably has an annular or sleeve-like configuration. The impact resistant layer 30 is most preferably composed of a polycarbonate material, such as LEXAN® (available from the General Electric Company), although a polycarbonate/ABS blend may also be used. The impact resistant layer 30 is preferably approximately 0.010 inches to 0.020 inches thick. Furthermore, the impact resistant layer 30 is preferably transparent, although a tint or full color embodiment may also be employed. The design of the impact resistant layer 30 allows the sleeve to be applied to the shaft of the hockey stick relatively easy. One preferred embodiment, as described below, provides a polycarbonate sleeve having a longitudinal slit 32 extending along the entire length of the sleeve. The longitudinal slit 32 provides a means for expanding the sleeve such that it snaps or slides over the shaft 14 of the hockey stick 10.

[0032] As seen in FIG. 2, the impact resistant layer 30 preferably includes a slightly thicker portion of polycarbonate material adjacent the corners of the shaft 14. The additional material present in the corners of the shaft 14 enhances protection to the hockey stick where impact is most likely to occur. This slight modification provides the impact resistant layer 30 with a more durable configuration.

[0033] In addition to the multiple layers described above, various decals or designs may be added to the body of the shaft. The preferred application of a decal is provided by bonding the decal onto the acrylic adhesive 29a present on the outer surface of the energy absorbing layer. A transparent polycarbonate impact resistant layer 30 is then placed over the decal in order to provide impact resistance for the hockey stick 10. The transparent polycarbonate layer allows the decal to be viewed through the sleeve.

[0034] FIGS. 3A-3C demonstrate various applications of the energy absorbing layer 28 and the impact resistant sleeve 30 to the shaft 14 of the hockey stick 10 and the various preferred embodiments.

[0035] FIG. 3A is a longitudinal cross-sectional view illustrating the application of the energy absorbing layer 28 and the impact resistant layer 30 to the lower portion 22 of the shaft 14.

[0036] FIG. 3B is a longitudinal cross-sectional view illustrating the application of the energy absorbing layer 28 and the impact resistant layer 30 to the lower portion 22 and the upper portion 24 of the shaft 14.

[0037] FIG. 3C is a longitudinal cross-sectional view illustrating the extension of the energy absorbing layer 28 and the impact resistant layer 30 from the lower portion 22 through the upper portion 24 and along the end plug 16. In general, the energy absorbing layer 28 and the impact resistant layer 30 may be applied anywhere along the body 26 of the shaft 14 and at various lengths. Therefore, the length of the energy absorbing layer 28 and impact resistant layer 30 applied to the body 26 of the shaft 14 is preferably based upon the desired performance of the hockey stick 10.

[0038] A preferred method of preparing the present invention is illustrated in FIGS. 4A-4C. Initially, a shaft body 26, which is usually rectangularly shaped, is provided. Next, the energy absorbing layer 28 having a sheet-like configuration is applied to the shaft body 26. As seen in FIG. 4,A the energy absorbing layer 28 has a width substantially the same as the circumference of the shaft body 26. The length of the energy absorbing layer 28 may vary depending on the desired region of the shaft body 26 covered. The energy absorbing layer 28 is folded around the circumference of the shaft body 26 thereby providing a continuous layer around the wrapped region of the shaft body 26, as seen in FIG. 4A. The wrapping of the double-sided viscoelastic tape 28 bonds the interior side of the viscoelastic tape 28 to the outboard surface of the shaft body 14. Alternate methods may be used for applying the viscoelastic layer to the shaft body 14, such as helically wrapping the viscoelastic tape in a longitudinal direction along the shaft.

[0039] Although not shown in the figures, if desired, a decal or design bearing emblem may then be disposed on the outer surface of the viscoelastic tape. The bonding of the decal to the viscoelastic tape is preferably accomplished through use of the acrylic adhesive on the outer surface of the tape 28.

[0040] Following the positioning of the viscoelastic tape and the application of the decal or design to the outer surface of the viscoelastic tape, the impact resistant layer 30 is applied to the shaft body 14. Preferably, the impact resistant layer 30 is provided in the form of an annular sleeve 30 which is snapped over the body 26 of the shaft 14 by forcing the body 26 through the longitudinal slit 32 thereby expanding the sleeve. As seen in FIG. 4b, the longitudinal slit 32 provides a passage to an axial bore 34 formed throughout the impact resistant sleeve 30 for accommodating the shaft body 14. Following the placement of the impact resistant sleeve 30 around the body shaft 14 as seen in FIG. 4c, a polyurethane tape 36 is placed along the longitudinal slit 32 to secure the placement of the impact resistant sleeve 30. A section of polyurethane tape 36 may be applied around the opposing ends of the impact resistant sleeve in order to encapsulate the multilayered region of the shaft body.

[0041] As seen in FIG. 5, an alternate embodiment impact resistant layer 30′ and method for mounting the layer 30′ to the shaft 14′ is illustrated. In this embodiment, the layer 30′ takes the form of a circumferentially enclosed polycarbonate sleeve (not having a slit). Following the application of the viscoelastic tape 28′ and bonding of a decal (if desired), the polycarbonate sleeve 30′ having an axial bore 34′ formed therethrough is telescopically slid over the shaft body 26′. Various lubricants may be used to assist in the receipt of the shaft body 26′ within the bore 34′ of the polycarbonate sleeve 30′. Upon the placement of the shaft body 26′ within the polycarbonate sleeve 34′, polyurethane tape 36′ may be used to affix the ends of the polycarbonate sleeve 34′ to the shaft body 26′.

[0042] FIG. 6 illustrates a cross-sectional view of an alternate embodiment of the present invention which provides a shaft 14″ of the hockey stick 10″ having an impact resistant layer 30″ applied directly on the body 26″. This embodiment enhances the impact resistance of the shaft 14″, without modifying the energy absorption characteristics of the shaft 14″.

[0043] A further alternate embodiment, as seen in FIG. 7, provides a hockey stick 50 having a shaft 52 with a body 54 containing a recessed portion 56 annularly formed around the body 54 of the shaft 52. The recessed portion 56 is provided for concentrically accommodating the energy absorbing layer 28 and impact resistant layer 30 along the body 54 of the shaft 52. In the previously described embodiments of the present invention, the application of the energy absorbing layer and the impact resistant layer form a small ridge around the exterior circumference of the shaft. Depending on the desired length of the specific layers applied, the ridge formed by the ends of the energy absorbing layer and the impact resistant layer may be disfavored by certain players. In order to obtain a coplanar (smooth) external surface along the shaft 52 of the hockey stick 50, the energy absorbing layer 28 and the impact resistant layer 30 are applied within the recessed portion 56 provided in the body 54 of the shaft 52 as previously described in the alternate embodiments. The depth of the recessed portion 56 is selected to match the thickness of the energy absorbing layer 28 and impact resistant layer 30 (and any adhesive used in combination therewith) if both layers are employed, or the impact resistant layer 30 (and any adhesive) if only the impact resistant layer 30 is employed. As such, the recessed portion 56 of the body 54 provides the player with a planar shaft 52. The recessed portion 56 is preferably formed when molding the shaft 52 although other methods such as grinding may be used.

[0044] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.