Patent Publication Number: US-2016236050-A1

Title: Hockey stick blade and method of making same

Description:
TECHNICAL FIELD 
     The application relates generally to sporting equipment and, more particularly, to blades for hockey sticks. 
     BACKGROUND 
     Conventional hockey sticks, such as those used for playing ice or street hockey, may have a blade made from fiber-reinforced composite materials. Although such fiber-reinforced composite materials are stiff in specific directions of load and are also light, other materials may have more desirable properties, for example under impact loads and in vibration damping response. 
     SUMMARY 
     In one aspect, there is provided a blade for a hockey stick, comprising: a body adapted to be connected to the proximal end of a shaft, the body defining spaced apart first and second outer impact surfaces, each of the impact surfaces having a heel portion proximate a shaft connection point and a toe portion spaced apart from the shaft connection point, the body including an outer layer having an outer surface defining at least part of each of the first and second impact surfaces of the body, the outer layer made of a first material, the first material being a composite material; and a face member made from a second material different from the first material, the face member having opposed inner and outer surfaces interconnected by a peripheral edge, the face member overlaying and embedded in the body, the peripheral edge being in contact with the first material and at least a major part of the inner surface of the face member being in contact with the body of the blade, the outer surface of the face member defining part of the first impact surface of the body, the outer surface of the face member being aligned with the outer surface of the outer layer adjacent the face member such that the first impact surface of the body is continuous over a transition between the outer layer and the face member. 
     In another aspect, there is provided a method for making a hockey stick blade, comprising: positioning a face member over an outer surface of a layer of uncured composite material, the face member being made of a material different from the uncured composite material; putting the face member and the outer surface of the layer of uncured composite material extending around the face member in contact with a blade-shaped mold surface; and heating the uncured layer of composite material and applying pressure to the layer of uncured composite material against the mold surface until the face member is embedded in the layer of composite material and the composite material is cured. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Reference is now made to the accompanying figures in which: 
         FIG. 1  is a schematic tridimensional view of a hockey stick, according to an embodiment of the present disclosure; 
         FIG. 2  is a cross-sectional view of a blade of the hockey stick of  FIG. 1 , taken along the line II-II; 
         FIGS. 3A-3E  are schematic rear views of face members of a blade for a stick such as shown in  FIG. 1 , according to various embodiments of the present disclosure; and 
         FIGS. 3F-3G  are schematic front views of hockey stick blades with face members, according to various embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates generally a hockey stick  10  (or simply “stick  10 ”). The stick  10  can be used to play any suitable sport or activity, and is not strictly limited to the sport of ice hockey. The stick  10  has a generally elongated shaft  20  which can be manipulated by the user of the stick  10 , a blade  30  which is adapted to contact an object such as a ball or puck, and a face member  40  which reinforces portions of the blade  30 . 
     The shaft  20  joins, or is made integral with, the blade  30 , thereby forming the stick  10 . The shaft  20  is manipulated by the hands of the user in order to control the blade  30 . The shaft  20  therefore has a shaft body  22 , generally of a rectangular or oblong cross-section, which can be gripped by the user and which provides the corpus to the shaft  20 . Specifically, the shaft body  22  extends between a distal end  24  and a proximal end  26 . The distal end  24  corresponds to the free extremity of the shaft body  22 , and the proximal end  26  corresponds to the extremity of the shaft body  22  which is connected to, or made integral with, the heel or neck of the blade  30 . When the proximal end  26  is made integral with the blade  30 , such as during the manufacturing process of the stick  10 , the stick  10  is a one-piece, integral construction. 
     The shaft body  22 , and thus the shaft  20 , can take any suitable shape or have features and components which make it suitable for the activity for which it is used. For example, it may be desirous to reduce the weight of the shaft  20 , which constitutes a major component of the overall weight of the stick  10 . In such an instance, the shaft body  22  of the shaft  20  can be hollow so as to define an elongated body cavity. If it is desired to additionally reinforce the stiffness of shaft  20  while still providing the requisite flexibility, one or more longitudinal shaft ribs can be disposed within the body cavity, and extend between opposed interior walls of the shaft body  22 . Each shaft rib can extend along some portion, or all, of the length of the shaft body  22  between the first end  24  and the second end  26 . If so desired, one or more of the shaft ribs can be discontinuous along their length. It will therefore be appreciated that each shaft rib can reinforce the stiffness of the shaft body  22  along its length and/or along its width, while still providing the shaft body  22 , and thus the shaft  20 , with the desired amount of flexibility. 
     The blade  30  can be any suitable curved body which provides one or more impact surfaces to be used to manipulate the object. It can also be curved along its length to provide for improved manipulation of the object. Some portion, or all, of the blade  30  can be hollow in order to reduce the overall weight of the stick  10 . 
     Still referring to  FIG. 1 , the blade  30  has a body  31  which forms the corpus of the blade  30  and provides structure thereto. The body  31  is an elongated object which extends along a blade axis  32  between a heel portion  33  proximate the connection with the shaft  20  and a toe portion  34  spaced apart from the connection with the shaft  20 . The heel portion  33  generally defines a curved bottom edge of the body  31  which contacts the ice or playing surface when the stick  10  is in use. The toe portion  34  may otherwise be referred as the tip of the blade  30 . The body  31  may also have a neck portion, which defined a connection point of the blade  30  in direct contact with the proximal end  26  of the shaft  20 , and which is joined with this end so as to form the stick  10 . The general shape of the blade  30  is defined between these components, in that the body  31  of the blade  30  extends between the heel portion  33  and the toe portion  34 . It will be appreciated that the blade  30  can take shapes and configurations which differ from those shown in the figures. 
     Referring now to  FIG. 2 , the body  31  defines spaced-apart first and second outer impact surfaces  35 A,  35 B. Each of the impact surfaces  35 A,  35 B is a contact surface for impacting the object and providing a force thereto. The impact surfaces  35 A,  35 B may be exposed to the environment, or covered by a protective coating, for example transparent. In the embodiment shown, the first impact surface  35 A designates the “front” area of the body  31  which forms the primary contact surface with the object being manipulated, and is generally concave, while the second impact surface  35 B is a “rear” surface, generally convex. Both the first and second impact surfaces  35 A,  35 B extend along the entirety of the body  31  and define part of the heel portion  33  and of the toe portion  34 . The curvature and shape of the impact surfaces  35 A,  35 B therefore defines that of the blade  30 . 
     The body  31  has an outer material layer  37 . In a particular embodiment, the outer material layer  37  is made of composite material, and may be formed of a single or multiples connected plies of composite materials, with the multiple plies disposed in side by side and/or overlaying relationship. In the embodiment shown, the body  31  has an inner blade cavity  36  and the outer material layer  37  circumscribes this inner blade cavity  36 . The inner blade cavity  36  may be hollow; alternately, the inner blade cavity  36  may be filed with an appropriate type of material, for example an appropriate type of foam including, but not limited to, PVC or polyurethane foam. The outer material layer  37  delimits the thickness, length, and height of the inner blade cavity  36  within the body  31 . The outer surface of the outer material layer  37  forms at least part of each of the outer impact surfaces  35 A,  35 B. In the embodiment shown, the outer surface of the outer material layer  37  corresponds to the entire second impact surface  35 B and to a peripheral portion of the first impact surface  35 A, as will be further detailed below. 
     The outer material layer  37  may include any appropriate type of composite material, including, but not limited to, suitable fiber-reinforced polymers, for example fiber-reinforced epoxy. In a particular embodiment, the outer material layer  37  is made of an epoxy/carbon fiber material. In general, the outer material layer  37  consists of a fiber portion and a resin portion, the resin portion serving as a matrix in which the fibers are embedded in a defined manner. In a composite for hockey stick blades, for example, the composite material may be provided in prepreg form, superposed in a “lay-up” manner and then cured to a rigid condition using heat and pressure. 
     Still referring to  FIG. 2 , the blade  30  may have one or more internal ribs  38  spanning the inner blade cavity  36 . Each internal rib  38  reinforces the stiffness of the body  31  between the first and second impact surfaces  35 A,  35 B while helping to reduce the overall weight of the blade  30 , and thus the overall weight of the stick  10 . Each internal rib  38  may extend longitudinally along the blade axis between the heel portion and the toe portion. Alternatively, each internal rib  38  may extend transverse to the blade axis between the top and bottom edges of the body  31 . Irrespective of its orientation, each internal rib  38  forms a bridge between opposed inner surfaces of the outer material layer  37 , and can be formed during the making of the blade  30  using any suitable technique. In a particular embodiment, each internal rib  38  is made of the same composite material as the outer material layer  37 ; alternately, different materials may be used. The internal rib  38  can consist of a single, substantially uninterrupted body. Alternately, a number of discrete internal ribs  38  can be used forming rib sections which are spread apart. Each rib section divides the inner blade cavity  36  into separate hollow channels. 
     Still referring to  FIG. 2 , the blade includes at least one face member  40  made of a material different from that of the outer material layer  37 . The material of the face member(s)  40  is selected depending on the property of the blade  30  which is designed to be tailored by it. For example, the material of the face member(s) may be more rigid in torsion and/or bending, more resistant to cracks, have increased vibration dampening properties, and/or have a more isotropic rigidity than the material of the outer material layer  37 . In a particular embodiment, each face member  40  provides a localized zone of increased reinforcement over the portion of the body  31  where it is located. Such reinforcement may provide for an increased durability of the blade  30 , a better feel and control of the blade  30  by users of the stick  10 , and/or a modification of the stiffness and torsional rigidity of the blade  30 , for example. Some examples of suitable materials for the face member  40  include composite materials different from that of the outer material layer  37 , ceramics, ceramic matrix composites (CMC), polymer/elastomer materials, organic materials, metals, alloys, metal matrix composites (MMC), etc. In a particular embodiment, the face member  40  is made of a metal material, for example 6-4 titanium alloy (α-β Ti) or 7075 aluminum alloy, such as to provide suitable isotropic rigidity properties which help to stiffen the blade  30  in both bending and torsion efficiently. Therefore, using a metal material for the face member  40  represents a potential upgrade in blade durability and responsiveness due to the isotropic properties of metal materials. 
     Each face member  40  has an inner surface  42 A and an outer surface  42 B spaced apart from one another across the thickness of the face member  40 , and a peripheral edge  44  interconnecting the inner and outer surfaces  42 A,  42 B. In the embodiment shown, the face member  40  is embedded in the body  31  by being embedded in the outer material layer  37 : at least a major part of the peripheral edge  44  and of the inner surface  42 A are in contact with the material of the outer material layer  37 . In the embodiment shown in  FIG. 2 , the entirety or substantially the entirety of the peripheral edge  44  and of the inner surface  42 A are in contact with the material of the outer material layer  37 . 
     In a particular embodiment, the peripheral edge  44  is bevelled, such that the perimeter of the inner surface  42 A is smaller than the perimeter of the outer surface  42 B, which may facilitate contact between the peripheral edge  44  and the outer material layer  37 . In a particular embodiment, the material of the outer material layer  37  may extend over a periphery of the face member  40 , such that only a central portion of the face member  40  is exposed and visible. In the embodiment shown, the outer surface  42 B of the face member  40  defines part of the first impact surface  35 A, surrounded by the outer material layer  37  defining the remaining part of the first impact surface  35 A. 
     The outer surface  42 B of the face member  40  is aligned with the adjacent outer surface of the outer material layer  37 , such that the first impact surface  35 A is continuous over the transition between the outer material layer  37  and the face member  40 . The outer surface  42 B of the face member  40  is therefore flush or level with the adjacent outer surface of the outer material layer  37 , and is thus able to enter into contact with the playing object. 
     Although a single face member  40  is shown, the blade  30  may alternately include two or more face members embedded in the body  31 , each defining a part of one of the impact surfaces  35 A,  35 B. The face member  40  may also include multiple layers of material embedded in the body  31 . 
     In a particular embodiment, the blade  30  is integrally formed. The expression “integrally formed” refers to the relationship between the face member(s)  40  and the materials of the body  31  (outer material layer  37 , foam if applicable), in that the face member(s)  40  are embedded in the body  31 , for example in the outer material layer  37 , during its molding process, incorporating the face member(s)  40  in the cured material layer  37  in the finished blade  30 . In a particular embodiment, such an integral construction reinforces the bond between the material layer  37  and face member(s)  40  to reduce the chances of detachment of the face member(s)  40  during use, for example by contrast to heads for striking objects where a reinforcement piece is adhered or otherwise applied separately to the head after it has been manufactured. 
     In the embodiment of  FIGS. 1-2 , the face member  40  extends along a direction which is transverse to the longitudinal blade axis to span across one or more internal ribs  38 . The relationship between the face member  40  and the internal ribs  38  may vary. For example, the face member  40  may overlay a portion of the outer material layer  37  spanning across two internal ribs  38 , each rib  38  extending near opposite ends of the face member  40 . The face member  40  may overlay a portion of the outer material layer  37  spanning across three internal ribs  38 , for example two ribs  38  extending near opposite ends of the face member  40 , and a third rib  38  disposed between these two ribs  38 . 
     In an embodiment where the internal cavity  36  is filled with foam, the face member  40  may be embedded in the body  31  by being embedded in the outer material layer  37 , such that at least a major part (and preferably, the entirety or substantially the entirety) of the peripheral edge  44  and of the inner surface  42 A are in contact with the material of the outer material layer  37 —i.e., the outer material layer  37  extends between the face member  40  and the foam. Alternately, the face member  40  may be embedded in the body  31  by having at least a major part (and preferably, the entirety or substantially the entirety) of the peripheral edge  44  in contact with the material of the outer material layer  37 , the outer material layer  37  optionally overlapping a periphery of the outer surface  42 B of the face member  40 , and with that at least a major part (and preferably, the entirety or substantially the entirety) of the inner surface  42 A supported by and in contact with the foam and with the ribs  38  if such are present. 
     In a particular embodiment, having the face member  40  embedded in the body  31  allows for the face member  40  to have a greater impact on the properties of the body  31 , for example in contrast to heads for striking objects where the reinforcement piece is applied only against inner ribs spanning a hollow cavity of the head. 
     It has been observed that putting a metal material between the playing object and the composite material of the blade face has positive performance aspects in terms of user perception. Users have experienced a noticeable feel improvement when the material of some or all of the blade face is changed. In a particular embodiment, damping and impact toughness is taken up by the metal material of the face member  40 , while the composite material of the blade  30  makes the blade  30  stiff in specific directions of load. 
     It can thus be appreciated that the one or more face member(s)  40  can assume different shapes and configurations in order to achieve such functionality. For example, the face member  40  may extend along the periphery of the body  31  along the top and/or bottom edges thereof, in the toe portion and/or the heel portion of the blade  30 , depending on the property(ies) of the blade to be tailored by the face member(s)  40 —i.e. wear resistance, stiffness, impact resistance, vibration dampening, etc. 
     Referring to  FIG. 3A , an alternate configuration for the face member  40 A is shown. The Figure shows the inner surface which is to be received against the body  31  (for example against the outer material layer  37 ). The face member  40 A is shaped as a varying thickness metal plate extending longitudinally along a length of the body of the blade between the heel portion and the toe portion. As can be seen, the inner surface of the face member  40 A includes a central protuberance  41 A forming a zone of increased thickness with respect to a remainder of the face member  40 A. The protuberance  41 A has an irregular shape and extends along the length of the length of the face plate  40 . The protuberance  41 A may help to reinforce those regions of the outer impact surface  35 A of the blade  30  which are most often in contact with the playing object. In a particular embodiment, the shape of the protuberance is determined to correspond to regions of highest load or highest deflection in the blade  30  under particular constraint conditions. 
     Referring to  FIG. 3B , another alternate configuration for the face member  40 B is shown. As for the previous embodiment, the Figure shows the inner surface which is to be received against the body  31  (for example against the outer material layer  37 ). The face member  40 B is shaped as a varying thickness metal plate extending longitudinally along a length of the body of the blade between the heel portion and the toe portion. As can be seen, the inner surface of the face member  40 B also includes a central protuberance  41 B forming a zone of increased thickness with respect to a remainder of the face member  40 B. The protuberance  41 B has an irregular shape and extends along the length of the length of the face plate  40 , covering more of the toe portion that that of the previous embodiment. The shape of the protuberance  41 B may be determined to correspond to regions of highest load or highest deflection in the blade  30  under particular constraint conditions different from those of the previous embodiment. 
     Referring to  FIG. 3C , in another alternate configuration for the face member  40 C, both the inner and outer surfaces may be smooth, defining a thickness of the face member  40 C which is uniform along its length, and accordingly may be easier to manufacture than the face members  40 A,  40 B. 
     Referring to  FIG. 3D , another alternate configuration for the face member  40 D is shown. As for the previous embodiments, the Figure shows the inner surface which is to be received against the body  31  (for example against the outer material layer  37 ). The metal face member  40 D is shaped as a plate extending longitudinally along a length of the body of the blade between the heel portion and the toe portion, with the inner surface including multiple reinforcement blocks  41 D forming local zone of increased thickness with respect to a remainder of the face member  40 D. The thickness of the reinforcement blocks  40 D can be uniform or vary between blocks  40 D. 
     Referring to  FIG. 3E , another alternate configuration for the face member  40 E is shown. As for the previous embodiments, the Figure shows the inner surface which is to be received against the body  31  (for example against the outer material layer  37 ). The metal face member  40 E includes another configuration of plate and reinforcement blocks  41 E forming local zone of increased thickness with respect to a remainder of the face member  40 D. The thickness of the reinforcement blocks  40 E can be uniform or vary between blocks  40 E. “Lattice”-like configuration such as the face members  40 D,  40 E may be easier to manufacture than the configurations of  FIGS. 3A and 3B . 
     In the embodiments of  FIGS. 3A-3E , the outer surface of the face member, which in use is the visible surface, may be smooth or alternately be provided with a textured pattern, or with raised features defining a variation in thickness, for example similarly to the inner surface. 
       FIG. 3F  shows an alternate configuration for the face member  40 F, shown here embedded in the outer material layer  37  to define the body of the blade  30 . It can be seen that the face member  40 F, which can have an inner surface with any of the above-described configurations, extends from the bottom edge of the blade  30  along the entire length of the blade, covers a majority of the toe portion and only a small part of the heel portion, while the top portion of the blade  30  is free from the face member  40 F. In a particular embodiment, such a configuration used with a face member  40 F made of metal material provides for increased stiffness in bending and torsion, by comparison with a similar blade made only with the composite material. 
       FIG. 3G  shows another alternate configuration for the face member  40 G, also shown embedded in the outer material layer  37  to define the body of the blade  30 . It can be seen that the face member  40 G extends from the bottom edge of the blade  30  in the heel portion only, forming a band coming higher in the toe portion such that the top and bottom edges of the blade in the toe portion are left uncovered. In a particular embodiment, such a configuration used with a face member  40 F made of metal material provides for increased stiffness in torsion, by comparison with a similar blade made only with the composite material. 
     The shape of the face member can thus be selected in accordance with the property of the body  31  to be changed, for example the stiffness in torsion and/or bending. 
     There is also disclosed herein a method for making a hockey stick blade, such as the one described herein. The method involves the use of a mold, and curing using heat and pressure. 
     In a particular embodiment, the outer material layer  37  is formed in its uncured state by one or more plies of prepreg wrapped around a bladder, or around a foam core; in the case of a blade with internal ribs, multiple bladders/foam cores may be individually wrapped with prepreg material to define the ribs, and the wrapped bladders/foam cores are then wrapped together with prepreg material to form the outer material layer  37 . The face member is positioned over the uncured outer material layer  37 , or against the foam core and surrounded by the outer material layer  37 . 
     To facilitate bonding between the face member and the composite material layer or foam underneath it, the inner surface of the face member may be abraded prior to assembly. Adhesive can also be added between the face member and composite material layer or foam, for example in the form of an adhesive resin film. 
     The face member and uncured outer material layer adjacent to it are then put into contact with a mold surface defining the desired shape for the blade impact surface. The mold surface typically forms part of a mold enclosure which encloses the uncured composite material wrapped around the bladder(s)/foam core(s) together with the face member to form the blade. 
     The uncured outer material layer  37  is heated while pressing it against the mold surface, for example by inflating the bladder(s) and/or applying pressure with the mold surfaces. As it is heated, the composite material first softens, and the pressure and heat allow the face member to “sink” and become embedded in the outer material layer  37 ; the face member and composite material around it being pressed against the mold surface ensuring the formation of a continuous impact surface. The assembled composite material and face member are heated and compressed until the composite material is cured, the face member remaining embedded in it. 
     In embodiments where bladders are used, the cavities created in the cured blade when the bladders are removed may be filled with material such as expandable foam, or alternately may remain hollow. 
     In a particular embodiment, the face member is made of a material that is in desired or cured state before assembly with the uncured outer material layer, for example a metal, an alloy, or a cured composite material. In another embodiment, the face member is made of another material that is uncured or partially cured, and reaches its desired cured state simultaneously with the curing of the outer material layer. 
     A coating, for example a clear protective coating, may be applied over the impact surfaces of the cured blade, for example for increased durability. 
     Alternate methods of fabrication are also possible. 
     It can thus be appreciated from the above disclosure that the potential structural benefits of providing a metal face member allows to gain some advantages of having a metal blade without the weight penalty associated with having an all-metal blade. Indeed, fiber-reinforced composite material is stiff and light, but is inferior to metal under impact loads and in vibration damping response. Utilizing metal and composite to their respective strengths therefore contributes to improving blade performance. 
     The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without departing from the scope of the invention disclosed. Still other modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the appended claims.