Shaft for a hockey stick

Abstract

A shaft for a hockey stick, having a wooden core and inner and outer layers. One of inner and outer layers comprises an array of roving filaments and a composite laminate strip extending along at least a portion of the shaft. The composite laminate strip is adapted to alter the bending characteristics of the shaft by rigidifying a portion of the shaft. The array roving filaments and the composite laminate strip are embedded into an outer molded plastic layer. A blade is secured to one end of the shaft.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to a shaft for a hockey stick. The shaft comprises a wooden core and a synthetic layer including an array of roving filaments and a composite laminate strip. The invention also relates to a hockey stick comprising such a shaft.

BACKGROUND OF THE INVENTION

[0002] In the game of hockey, the most powerful shot a player can make is the slap shot. The player executes the slap shot by winding up the hockey stick and descending the blade of the stick towards the puck in a circular or elliptic motion at maximum velocity to strike the puck with maximum speed and force. For best results, the blade of the hockey stick must contact the ice surface a short distance behind the puck before striking the puck to produce a whiplash effect. In so doing, the shaft of the hockey stick bends backward around a point of flexion defined by the lower hand of the player, storing potential energy, which is released when the shaft of the hockey stick unbends and the blade of the stick strikes the puck. In a slap shot, the shaft of the hockey stick acts as a bow, storing energy during the very short bending period of the shaft and releasing its stored energy when it straightens elastically and strikes the puck.

[0003] Various hockey stick shaft constructions exist on the market today adapted to produce a slap shot. Good hockey sticks are made of laminated hardwood, reinforced softwood, composite materials, and combinations thereof. Laminated hardwood or softwood shafts are often reinforced with a layer of fiberglass to increase their durability and rigidity. Composite shafts are generally hollow and most often made to shape with a filament winding or a wrapping process. The cost of composite shaft is often prohibitive. In each type of construction, the hockey stick shaft displays a constant stiffness throughout the length of the shaft. As such, in a slap shot dynamic motion the shaft bends evenly around the lower hand of the player and releases its stored energy over the entire length of the shaft.

[0004] Considering the importance of the energy storing capacity of a hockey stick shaft an more particularly of its energy releasing properties, there is a need for a hockey stick or hockey stick shaft having bowing or bending characteristics designed to increase the energy transfer from the hockey stick blade to the puck in a slap shot dynamic motion.

SUMMARY OF THE INVENTION

[0005] It is thus an object of the present invention to provide a hockey stick having improved energy releasing characteristics during a slap shot dynamic motion.

[0006] As embodied and broadly described herein, the invention provides a shaft for a hockey stick, said shaft comprising a longitudinal axis; a wooden core extending along said longitudinal axis, said wooden core comprising inner and outer sides extending along said longitudinal axis and rear and front sides between said inner and outer sides; and inner and outer synthetic layers recovering said inner and outer sides respectively; one of said inner and outer synthetic layers comprising an array of roving filaments extending along said longitudinal axis and a composite laminate strip extending along at least a portion of said shaft for rigidifying said portion. The composite laminate strip is in fact adapted to alter the bending characteristics of the shaft by rigidifying a portion of the shaft. The array roving filaments and the composite laminate strip are embedded into the outer molded plastic layer. Finally a blade is secured to one end of the shaft.

[0007] Advantageously, the disposition of the composite laminate strip or strips along the sides of the shaft alters the bowing or bending characteristics of the shaft such that the whiplash effect of the shaft when it releases its stored energy is concentrated in a specific portion of the hockey stick.

[0008] Other objects and features of the invention will become apparent by reference to the following description and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] A detailed description of the preferred embodiments of the present invention is provided herein below, by way of example only, with reference to the accompanying drawings, in which:

[0010] FIG. 1 is a side elevational view of a hockey shaft according to a first embodiment of the invention.

[0011] FIG. 2 is a cross sectional view of the shaft taken at line 2-2 of FIG. 1.

[0012] FIG. 3 is a partial side view of one face of the shaft shown in FIG. 1 illustrating some construction details of the shaft.

[0013] FIG. 4 is a perspective view of the hockey shaft of FIG. 1 held by a hockey player.

[0014] FIG. 5 is a front elevational view of the hockey shaft of FIG. 1.

[0015] FIGS. 6A and 6B are side elevational views showing each side of a hockey shaft according to a second embodiment of the invention.

[0016] FIGS. 7A and 7B are side elevational views showing each side of a hockey shaft according to a third embodiment of the invention.

[0017] FIGS. 8A and 8B are side elevational views showing each side of a hockey shaft according to a fourth embodiment of the invention.

[0018] FIGS. 9A and 9B are side elevational views showing each side of a hockey shaft according to a fifth embodiment of the invention.

[0019] In the drawings, preferred embodiments of the invention are illustrated by way of examples. It is to be expressly understood that the description and drawings are only for the purpose of illustration and are an aid for understanding. They are not intended to be a definition of the limits of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0020] FIG. 1 illustrates a hockey stick 10 comprising a shaft 12 and a blade 14. The shaft 12 is elongated and has a generally rectangular cross section defined by a first pair of substantially parallel inner and outer wide sides 11 and a second pair of substantially parallel front and rear sides 13 best shown in FIG. 2. The sides 11 and 13 need not be flat surfaces and may be slightly concave or convex. Shaft 12 has a proximal end 16 and a distal end 18 to which blade 14 is secured.

[0021] The inner end 20 of blade 14 is of reduced cross-section and is adapted to fit into a slot in the distal end 18 of the shaft 12 and a high quality glue is used to secure blade 14 thereto in a conventional manner. It is understood that blade 14 may be integrally formed with shaft 12. Blade 14 is normally made of solid hardwood as a one-piece component but may also be of a laminated construction. Blade 14 and the distal end 18 are usually reinforced with a thin woven glass fiber or graphite strip placed over blade 14 and the distal end 18 and secured with an adhesive such as epoxy glue.

[0022] As illustrated in FIG. 2 which is a cross sectional view of shaft 12 taken at line 2-2, shaft 12 comprises a softwood core 24 of either laminated construction or a one-piece component. Each wide side 11 of shaft 12 is recovered by a synthetic layer 28. Synthetic layer 28 comprises an array of heavy gauge fiberglass roving filaments 26 extending the length of shaft 12 and a pre-cured composite laminate strip 22 of graphite and/or aramide fibers. The roving filaments 26 may also be made of carbon fibers, graphite or aramide fibers. The pre-cured composite laminate strip 22 is secured to the fiberglass roving filaments 26 and the softwood core 24 with an adhesive such as epoxy glue to prevent potential delamination of strip 22. The entire shaft 12, including roving filaments 26 and composite laminate strips 22, is embedded in an outer molded plastic layer 28. Laminate strip 22 is positioned above the fiberglass roving filaments 26 and cured into the molded plastic layer 28.

[0023] As illustrated in FIG. 3 which is a partial side view of the wide face 11 of shaft 12, the heavy gauge fiberglass roving filaments 26 extend longitudinally the length of shaft 12 from the proximal end 16 to the distal end 18. In the fabrication process, the fiberglass roving filaments 26 are stretched longitudinally over the softwood core 24 during the curing of the plastic layer 28. Fiberglass roving filaments 26 are thus pre-tensioned once embedded into the outer molded plastic layer 28 and increase the stiffness of shaft 12. The pre-cured composite laminate strip 22 is positioned over the fiberglass roving filaments 26 and is also cured into the outer molded plastic layer 28. The pre-cured composite laminate strip 22 and the pre-tensioned fiberglass roving filaments 26 define the general bending characteristics of shaft 12 in a direction perpendicular to blade 14; fiberglass roving filaments 26 providing a constant or equal increase in stiffness along the length of shaft 12 while composite laminate strip 22 provides a localized stiffness increase in the middle portion of the wide side 11 of shaft 12. The stiffness of shaft 12 is therefore maximal in its middle portion where pre-cured composite laminate strip 22 is, and decreases at its ends 16 and 18.

[0024] As shown in FIG. 4, pre-cured composite laminate strip 22 is strategically located in the middle portion of shaft 12 where the player's lower hand is generally positioned. When executing a slap shot, the central point of bending of shaft 12 is the exact position of the player's lower hand. As shown schematically in FIG. 5, the player's upper hand depicted by arrow 32 applies a downward pressure on shaft 12 and blade 14 against the ice surface 30 while the player's lower hand as depicted by arrow 34 applies a forward pressure to the middle portion of shaft 12. The combination of these forces has the effect of bowing shaft 12 around the player's lower hand at arrow 34. Since the middle portion 36 is substantially reinforced by the pre-cured composite laminate strips 22, the bowing of shaft 12 is more pronounced in the segments 35 and 37 of shaft 12 at the proximal end 16 and the distal end 18 of shaft 12 than in its middle portion 36. As in a modern bow, this configuration of hockey stick 10 enables to release more of the potential energy stored when bending shaft 12 through the extremities of shaft 12. The resulting energy release transferred to the puck when hockey stick 10 reaches a point where shaft 12 unwinds is thereby increased because the desired whiplash effect is concentrated in the two short segments 35, 37 which unwind faster than a conventional hockey stick where the entire length of shaft 12 unwinds at a constant rate. In a typical slap shot dynamic motion, the proximal end 16 of shaft 12 is held by the upper hand of the player and serves as a pivot point wherein minimal energy is released there. A large portion of the energy stored is routed into segment 37 and into blade 14. In hockey stick 10, the rate of speed of blade 14 as it strikes the puck 39 is thereby maximized to produce a faster shot.

[0025] In the illustrated hockey stick 10 of FIG. 5, the forward wide side A of shaft 12 forms a convex curvature and the entire wide surface of side A is therefore under tension. The rear wide side B of shaft 12 forms a concave curvature and the entire wide surface of side B is therefore under compression. Specifically, the pre-cured composite laminate strip 22A is under tension and the pre-cured composite laminate strip 22B is being compressed. The energy storage and release of shaft 12 is to a large extent carried out by the side A which is under tension and to a smaller extent, by side B which is under compression. Because of this distribution of energy storage and release, it is possible to fine-tune the position and length of the pre-cured composite laminate strip 22 for each side to marginally alter the bowing characteristics of hockey stick 10 for left hand players or right hand players.

[0026] FIGS. 6A and 6B illustrate a hockey stick 40 according to a second embodiment of the present invention in which only the wide side A of shaft 42 is reinforced with a pre-cured composite laminate strip 22. Hockey stick 40 is specifically designed for left-hand players where the forward side A is stiffer in the middle portion than at its proximal and distal ends 16 and 18. Shaft 42 behaves essentially like shaft 12 previously described. The un-reinforced segments at the proximal and distal ends 16 and 18 of shaft 42 will bend more than the reinforced middle portion of shaft 42 such that when releasing the potential energy stored during a slap shot dynamic motion, the whiplash effect will be concentrated in segment 41 near the distal end 18. Wide side B is not reinforced and therefore has a constant stiffness throughout the length of shaft 42. However, since wide side B is under compression in a slap shot situation, its contribution to the energy transfer from blade 14 to the puck is minimal and the overall energy release characteristics of hockey stick 40 remains similar to shaft 12 previously described. With an identical pre-cured composite laminate strip 22 as used in hockey stick 10, hockey stick 40 is marginally softer. Obviously, the shaft 42 of a hockey stick 40 designed for right-hand players would be a mirror image of the one illustrated in FIGS. 6A and 6B. The pre-cured composite laminate strip 22 would be positioned on the face of wide side B which would be the side facing forward for a right-hand player and would therefore be the side under tension in a slap shot dynamic motion. It is understood that composite laminate strip 22 may extend along the entire length of shaft 12 in a variant of the second embodiment illustrated in FIGS. 6a and 6b.

[0027] FIGS. 7A and 7B illustrate a hockey stick 50 according to a third embodiment of the present invention. Again, hockey stick 50 is designed for a left-hand player with wide side A facing forward and under tension in a slap shot dynamic motion. In this embodiment, a pre-cured composite laminate strip 52A is positioned in the upper portion of wide side A and pre-cured composite laminate strip 52B is positioned in the lower portion of wide side B. With this configuration, the pre-cured composite laminate strips 52A and 52B overlap in the middle portion of shaft 51. The lower portion of shaft 51 is more flexible below composite laminate strip 52A than its upper portion. However, the composite laminate strip 52B on side B of shaft 51 is located in the lower portion of shaft 51 and rigidifying marginally rigidities the lower portion. Since hockey stick 50 is designed for left-hand players, side B of shaft 51 is being compressed under slap shot condition and side A is under tension. As such, the lower portion of shaft 51 remains softer than its upper portion. Under slap shot condition, shaft 51 bends or bows more below the composite laminate strip 52A and provides a whiplash effect when releasing the energy stored in the initial phase of the slap shot dynamic motion. This configuration provides a softer shaft 51 giving a more evenly distributed whiplash effect. The variation of stiffness of side A of shaft 51 which is under tension in the initial phase of the slap shot, creates a whiplash effect extending from the lower end of composite laminate strip 52A down to the blade 14. A hockey stick 50 of this configuration designed for right-hand players is a mirror image of the hockey stick 50 illustrated in FIGS. 7A and 7B.

[0028] FIGS. 8A and 8B illustrate a hockey stick 55 according to, a fourth embodiment of the present invention. Again, hockey stick 55 is designed for a left-hand player with wide side A facing forward and under tension in a slap shot dynamic motion. In this embodiment, a pre-cured composite laminate strip 56A is positioned in the lower portion of side A and pre-cured composite laminate strip 56B is positioned in the upper portion of side B. In this configuration, the pre-cured composite laminate strips 56A and 56B overlap in the middle portion of shaft 57. The upper portion of shaft 57 is more flexible above composite laminate strip 56A because it is only reinforced on side B which is under compression in slap shot condition and therefore less solicited. The composite laminate strip 56B located on side B of shaft 57 rigidifying marginally the upper portion of shaft 57. As hockey stick 55 is designed for left-hand players, under slap shot condition, shaft 57 bends or bows more above the composite laminate strip 56A providing a soft whiplash effect in which the energy stored in the initial phase of the slap shot is released through the length of composite laminate strip 56A. This configuration provides a harder feeling shaft 57 having a whiplash effect concentrated in its upper portion. Hockey stick 55 feels very stiff and is best suited for strong players that enjoy a very rigid hockey stick as the lower portion bends or bows less than its upper portion. A hockey stick 55 of this configuration designed for right-hand players is a mirror image of the hockey stick 55 illustrated in FIGS. 8A and 8B.

[0029] FIGS. 9A and 9B illustrate a hockey stick 60 according to a fifth embodiment of the present invention. Again, hockey stick 60 is designed for a left-hand player with wide side A facing forward and under tension in slap shot condition. In this embodiment, a pre-cured composite laminate strip 62A is positioned in the middle portion of side A and a pre-cured composite laminate strip 63B, extending the entire length of the shaft 64, is positioned on the wide face of side B. In this configuration, hockey stick 60 behaves essentially as hockey stick 10 depicted in FIG. 5 in slap shot conditions. The pre-cured composite laminate strip 62B reinforces the entire length of side B and therefore has a constant rate of flexion under load. The middle portion of side A of shaft 64 is reinforced or rigidified by pre-cured composite laminate strip 62A leaving segments 65 and 67 at each extremities 16 and 18 of shaft 64 only reinforced by the array of fiberglass filaments 26 shown in FIGS. 2 and 3. Upper and lower segments 65 and 67 of shaft 64 are therefore softer or less rigid than the middle portion of the shaft. Under slap shot condition, hockey stick 60 bends more at each extremity 16 and 18 than in the middle portion as depicted in FIG. 5. However the difference in curvature between the central portion and the extremities is less pronounced than in hockey stick 10 because of the reinforced side B. This configuration of shaft 64 is in fact very similar to the second embodiment of the invention illustrated in FIGS. 6A and 6B except that side B is reinforced with a composite laminate strip throughout the entire length of shaft 64. Side B of shaft 64 therefore also has a constant stiffness throughout the length of shaft 64. However shaft 64 is more rigid the shaft 42 again because side B is reinforced throughout its entire length. This configuration of hockey stick 60 provides a generally rigid shaft 64 having softer upper and lower segments 65 and 67 that create a whiplash effect in the lower segment 65 of shaft 64 under slap shot condition. A hockey stick 60 of this configuration designed for right-hand players is a mirror image of the hockey stick 60 illustrated in FIGS. 9A and 9B.

[0030] All embodiments of the hockey stick disclosed herein are made of a softwood core of either laminated construction or a one-piece component reinforced with a series of pre-tensioned heavy gauge fiberglass or other yarn material roving filaments extending longitudinally along the length of shaft. A pre-cured composite laminate strip of carbon or graphite and/or aramide fibers is secured to the fiberglass roving filaments and the softwood core with an adhesive such as epoxy glue to prevent potential delamination of the composite laminate strip. The wide faces of the shaft, including the fiberglass roving filaments and the laminate strip or strips, are embedded in an outer molded plastic layer. The plastic layer is made by positioning the shaft into a mold and curing it. To obtain various bending or bowing characteristics, one or more pre-cured composite laminate strips are strategically positioned along the shaft's length, which define the behavior of the shaft of the hockey stick under slap shot condition.

[0031] The above description of preferred embodiments should not be interpreted in a limiting manner since other variations, modifications and refinements are possible within the spirit and scope of the present invention. The scope of the invention is defined in the appended claims and their equivalents.

Claims

1. A shaft for a hockey stick, said shaft comprising:

(a) a longitudinal axis;

(b) a wooden core extending along said longitudinal axis, said wooden core comprising inner and outer sides extending along said longitudinal axis and rear and front sides between said inner and outer sides; and

(c) inner and outer synthetic layers recovering said inner and outer sides respectively; one of said inner and outer synthetic layers comprising an array of roving filaments extending along said longitudinal axis and a composite laminate strip extending along at least a portion of said shaft for rigidifying said portion.

2. A hockey shaft as defined in claim 1 wherein said shaft has a generally rectangular cross-section, said inner and outer sides are larger that said rear and front sides and said array of roving filaments and said composite laminate strip are embedded together into said synthetic layer.

3. A hockey shaft as defined in claim 2 wherein said shaft and said composite laminate strip are characterized by a respective length, the length of said composite laminate strip being substantially less than the length of said shaft.

4. A hockey shaft as defined in claim 3 wherein said composite laminate strip is positioned in a middle portion of said shaft.

5. A hockey shaft as defined in claim 3 wherein said composite laminate strip is offset toward a lower portion of said shaft.

6. A hockey shaft as defined in claim 3 wherein said composite laminate strip is offset toward an upper portion of said shaft.

7. A hockey shaft as defined in claim 1 wherein said inner synthetic layer comprises an inner composite laminate strip and said outer synthetic layer comprises an outer composite laminate strip.

8. A hockey shaft as defined in claim 7 wherein said inner composite laminate strip is offset toward a lower portion of said shaft and wherein said outer composite laminate strip is offset toward an upper portion of said shaft.

9. A hockey shaft as defined in claim 7 wherein said inner composite laminate strip is offset toward an upper portion of said shaft and wherein said outer composite laminate strip is offset toward a lower portion of said shaft.

10. A hockey shaft as defined in claim 3 wherein the length of said composite laminate strip is equivalent to the length to said shaft.

11. A hockey shaft as defined in claim 1 wherein said inner layer comprises a composite laminate strip that extends along the entire length of said shaft.

12. A hockey stick comprising a shaft as defined in claim 1.