Aspects of the disclosure relate generally to lacrosse heads and more specifically to struts for lacrosse head sidewalls.
Lacrosse head sidewalls typically include a top rail and a bottom rail. In many lacrosse heads, one or more struts connect the top rail to the bottom rail to provide rigidity to the head.
According to one embodiment, a lacrosse head includes a scoop end, a ball stop end, and first and second sidewalls, wherein the first sidewall includes a first top rail and a first bottom rail. A first strut is connected to the first top rail and the first bottom rail, the first strut having a longitudinal axis. A second strut is connected to the first top rail and the first bottom rail, the second strut having a longitudinal axis, the first and second struts being directly connected along at least a portion of their lengths. the lacrosse head has a vertical centerline plane which extends longitudinally from the ball stop end to the scoop end. An orthogonal projection of the longitudinal axes of the first and second struts onto the vertical centerline plane results in two projection lines which are substantially parallel to one another, and the longitudinal axes of the first and second struts are not parallel to one another.
According to another embodiment, a lacrosse head includes a scoop end, a ball stop end, and first and second sidewalls. The first sidewall includes a top rail and a bottom rail, the first sidewall top rail has a top rail inner surface, and the sidewall bottom rail has a bottom rail inner surface. The lacrosse head having a vertical centerline plane which extends longitudinally from a the ball stop end to the scoop end. A first unitary strut is connected to the top rail and the bottom rail, the first unitary strut having first and second inwardly-facing surfaces facing generally toward the vertical centerline plane. The first inwardly-facing strut surface connects to the top rail at a first connection location and connects to the bottom rail at a second location. The first connection location is positioned outwardly from the top rail inner surface by a distance d1. The second connection location is positioned either at the bottom rail inner surface or outwardly from the bottom rail inner surface by a distance d2 that is less than distance d1. The second inwardly-facing strut surface connects to the top rail at a third connection location and connects to the bottom rail at a fourth connection location. The fourth connection location is positioned outwardly from the bottom rail inner surface by a distance d4. The third location is positioned either at the top rail inner surface or outwardly from the top rail inner surface by a distance d3 that is less than distance d4.
According to a further embodiment, a lacrosse head includes a scoop end, a ball stop end, and first and second sidewalls, wherein the first sidewall includes a top rail and a bottom rail, the sidewall top rail has a top rail inner surface, and the sidewall bottom rail has a bottom rail inner surface. The lacrosse head has a vertical centerline plane which extends longitudinally from the ball stop end to the scoop end. Also included is a first strut connected to the top rail and the bottom rail, wherein the first strut connects to the top rail at a first connection location and connects to the bottom rail at a second location. The first connection location is positioned outwardly from the top rail inner surface relative to the vertical centerline plane. A second strut is connected to the top rail and the bottom rail, wherein the second strut connects to the top rail at a third connection location and connects to the bottom rail at a fourth location. The fourth connection location is positioned outwardly from the bottom rail inner surface relative to the vertical centerline plane. The first and second struts are directly connected to one another within zero to five millimeters of the top rail and within zero to five millimeters of the bottom rail.
According to yet another embodiment, a lacrosse head includes a scoop end, a ball stop end, and first and second sidewalls, wherein the first sidewall includes a top rail and a bottom rail, the sidewall top rail has a top rail inner surface, and the sidewall bottom rail has a bottom rail inner surface. The lacrosse head has a vertical centerline plane extending longitudinally from the ball stop end to the scoop end. Also included is a first strut connected to the top rail and the bottom rail, wherein the first strut connects to the top rail at a first connection location and connects to the bottom rail at a second location. The first connection location is positioned outwardly from the top rail inner surface relative to the vertical centerline plane. A second strut is connected to the top rail and the bottom rail, wherein the second strut connects to the top rail at a third connection location and connects to the bottom rail at a fourth location. The fourth connection location is positioned outwardly from the bottom rail inner surface relative to the vertical centerline plane. The first strut has a length extending from the first connection location to the second connection location, and the first strut is connected to the second strut along at least fifty percent of the length of the first strut.
According to a further embodiment, a lacrosse head includes a scoop end, a ball stop end, and first and second sidewalls, wherein the first sidewall includes a top rail and a bottom rail, the sidewall top rail has a top rail inner surface, and the sidewall bottom rail has a bottom rail inner surface. The lacrosse head having a vertical centerline plane extending longitudinally from the ball stop end to the scoop end. A first strut is connected to the top rail and the bottom rail, wherein the first strut connects to the top rail at a first connection location and connects to the bottom rail at a second location. The first connection location is positioned outwardly from the top rail inner surface relative to the vertical centerline plane. A second strut is connected to the top rail and the bottom rail, wherein the second strut connects to the top rail at a third connection location and connects to the bottom rail at a fourth location. The fourth connection location is positioned outwardly from the bottom rail inner surface relative to the vertical centerline plane. At least one of the first and second struts has a top surface that is both upwardly-facing and forwardly-facing, and that is flat from an innermost edge of the at least one of the first and second struts to an outermost edge of the at least one of the first and second struts.
According to another embodiment, a lacrosse head includes a scoop end, a ball stop end, and first and second sidewalls, wherein the first sidewall includes a top rail and a bottom rail, the sidewall top rail has a top rail inner surface, and the sidewall bottom rail has a bottom rail inner surface. The lacrosse head has a vertical centerline plane extending from the ball stop end to the scoop end. A first strut is connected to the top rail and the bottom rail, wherein the first strut connects to the top rail at a first connection location and connects to the bottom rail at a second location. The first connection location is positioned outwardly from the top rail inner surface relative to the centerline plane. A second strut is connected to the top rail and the bottom rail, wherein the second strut connects to the top rail at a third connection location and connects to the bottom rail at a fourth location. The fourth connection location is positioned outwardly from the bottom rail inner surface relative to the centerline plane. At least one of the first and second struts has a bottom surface which is both downwardly-facing and rearwardly-facing surface, and that is flat from an innermost edge of the at least one of the first and second struts to an outermost edge of the at least one of the first and second struts.
The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. Various embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:
Aspects of the invention are described herein with reference to certain illustrative embodiments and the figures. The illustrative embodiments described herein are not necessarily intended to show all aspects of the invention, but rather are used to describe a few illustrative embodiments. Thus, aspects of the invention are not intended to be construed narrowly in view of the illustrative embodiments. In addition, it should be understood that aspects of the invention may be used alone or in any suitable combination with other aspects of the invention.
A lacrosse head typically includes a throat for connection to a shaft, a ball stop region distal to the throat, and a scoop region at the far end of the head. Sidewalls connect the ball stop region to the scoop region. A pocket is attached to the head, typically by tying strings of the pocket to holes in the lacrosse head.
The support structure of the head is subject to various stresses during use. For example, catching, shooting, and passing the ball place compressive, tensile, and shear forces on components of the lacrosse head. Additionally, poke checking and other actions can also stress the lacrosse head components.
Sidewalls typically include a top rail and a bottom rail with the pocket connected to the bottom rail. In many lacrosse heads, one or more struts connect the top rail to the bottom rail to provide additional rigidity to the head.
During certain actions, such as shooting, some of the struts may primarily undergo tension, while others of the struts may primarily experience compression. According to embodiments of the disclosure herein, a tension strut is combined with a compression strut to form a combined strut extending between the top rail and the bottom rail; the combined strut being subject to both compressive and tensile forces. In some cases, the two struts are connected to one another at least near the top and/or bottom rails to reduce the number of regions where stress concentrations may be present. For example, stress may be concentrated at the connection location of a strut to a top rail where the strut transitions into the rail. By having a combined strut instead of two separated struts, the total perimeter of the transition region can be reduced, which may reduce the number of locations having the potential for fatigue stress and possible fatigue failure.
According to some embodiments of the present disclosure, a strut geometry is provided wherein the volume of material is reduced without unduly affecting the structural properties of the head. In some cases, various properties of the head, including the rigidity, may be improved. All else being equal, reducing the weight of a lacrosse head can be desirable to improve the speed and maneuverability that a player can achieve when handling a lacrosse stick. Reductions in weight can be achieved through the use of lightweight materials and/or by reducing the volume of material used in the lacrosse head. These approaches need to be balanced with other factors such as strength, durability, and stiffness, as some examples.
In some embodiments, two sidewall struts are connected to one another along their lengths. The two struts are arranged to have similar angles in the ball stop to scoop direction, and have one strut turned relative to the other in a side-to-side direction of the lacrosse head such that the struts cross one another. In embodiments illustrated herein, the struts cross each other, and in some cases contact each other, but they are not necessarily co-planar; one strut may be positioned distal to the other. That is, one strut may be positioned closer to the scoop end of the head than the other strut. One of the struts may resist primarily compressive forces while the other of the struts may resist primarily tension forces. By connecting the two struts as a unitary strut, the two struts reinforce one another which may reduce failure risk and/or reduce weight, while providing sufficient rigidity to the head.
For clarity of description, two portions of a unitary strut may be referred to herein as first and second struts. For example, unitary strut 122 has a first portion that includes a first inwardly-facing surface 141, and a second portion that includes a second inwardly-facing surface 142. These first and second portions may be referred to as first and second struts 127, 128. For purposes herein, calling out first and second struts does not necessarily mean that the first and second struts are separated by a distance from one another longitudinally. Instead, the first and second struts may form a unitary strut whereby the first and second strut directly connect to one another. The unitary strut may be integrally formed in some embodiments, or two struts may be separately formed and joined together. In some embodiments, a unitary strut may include first and second struts which directly contact one another only close to the top and/or bottom rails. In other embodiments, first and second struts may be non-unitary struts in that they are distinct struts which do not directly contact one another. In some embodiments, three or more struts may be directly connected to form a unitary strut.
First and second struts of a unitary strut may be directly connected along at least 50% of the length of one of the struts in some embodiments. In some embodiments, the direct connection extends along at least 60% of the length of one of the struts. In some embodiments, 70% of the length of at least one of the struts is directly connected to the other of the struts. And, in some embodiments, the struts may be directly connected along the entire length of at least one of the struts. For purposes herein, the length of a strut extends from its highest connection point at the bottom rail to its lowest connection point at the top rail.
An isolated view of unitary strut 122 is shown in
The second inwardly-facing surface 142 has an inner connection location 148 at the bottom rail which is set back from an inner surface 144 of the bottom rail farther than an inner connection location 146 of the first inwardly-facing surface 141 on the bottom rail. The inner connection location 148 of second inwardly-facing surface 142 is also set back from inner surface 144 of the bottom rail by a greater distance than the setback distance of an inner connection location 150 of the same surface (second inwardly-facing surface 142) from an inner surface 152 the top rail. In the illustrated embodiment, the inner connection location 150 at the top rail is at the inner surface of the top rail such that the setback distance is zero, though in some embodiments, the inner connection location 150 may be set back from the inner surface by a distance greater than zero.
A surface texture is provided on inwardly-facing surfaces 141, 142 in the illustrated embodiment. This surface texture is formed as part of the injection molding manufacturing process, though a surface texture may be added after molding in any suitable manner. In some embodiments, no surface texture is present on the inwardly-facing surfaces.
At the top end of strut 120, the second inwardly-facing surface 162 connects to top rail 110 at the inner surface of top rail 110. In some embodiments, the second inwardly-facing surface 162 connects to the top rail at a location which is set back from the inner surface of the top rail, but at a distance less than the distance between connection location 164 and inner surface 144 at the bottom rail.
First inwardly-facing surface 161 connects to bottom rail 114 at a connection location 166 which is at the inner surface of the bottom rail. As can be seen in
In some embodiments, the particular arrangement of a combined strut which includes first and second struts is selected by analyzing the stresses which occur in test struts under loading. Certain areas of a strut may be under tension while other areas experience compression and/or shear forces. After identifying regions of a strut which show limited or no stresses under loading, a strut can be designed which no longer includes those regions. The identification of the lower stress regions can be performed using finite element analysis or any other suitable method.
For example, the identified regions which are “removed” from an analyzed strut and not included in the final strut may be the gaps between the inner surfaces of the rails and the inwardly-facing surfaces of the strut as described above. Additionally, as described below with reference to
By pairing a distal strut with a proximal strut such that they abut one another, various advantages may be realized. As already mentioned above, such an arrangement may reduce the rail/strut connection locations where stress concentrations may lead to fatigue failure. Additionally, each strut may support the other to limit lateral deflections or buckling. Each strut also may provide additional compressive or tensile strength to the other strut when needed.
A collapsing core injection molding method may be used in some embodiments to manufacture various lacrosse heads disclosed herein. By using a collapsing core injection molding technique, a first strut can have an outward slant relative to vertical while a second strut can have an inward slant relative to vertical.
The struts of the present disclosure may include outwardly-facing surfaces which have a similar arrangement to the inwardly-facing surfaces. For example, as shown in
The connection location 186 of the first outwardly-facing surface 181 to the bottom rail is set back farther from the bottom rail outer surface a greater distance than the setback of a connection location 188 of the first outwardly-facing surface 181 to the top rail. The opposite is true of second outwardly-facing surface 182. Here, the connection location to the bottom rail is at the outer surface of the bottom rail, while the connection location at the top rail is set back from the outer surface of the top rail toward the inner part of the head.
The first outwardly-facing surface 181 meets with the second outwardly-facing surface 182 at a cross-over location 189 at the approximate midpoint between the top and bottom rails where the first and second struts cross over one another.
The first and second struts of combined strut 120 near the distal end of the head also cross over one another and create the outwardly-facing surfaces 191, 192 which have a similar arrangement to outwardly-facing surfaces 181, 182.
While third strut 124 does not have similar inwardly-facing surfaces as first and second struts 120, 122, third strut 124 does have first outwardly-facing surfaces 201, 202 which connect at different setback distances from the outer surface of the bottom rail. A cross-over location 205 of the two outwardly-facing surfaces 201, 202 occurs closer to the bottom rail than the top rail in the illustrated embodiment.
In some embodiments, the first and second struts of a combined strut are arranged such that the first strut has a substantially similar angle about an axis that is normal to the vertical centerline plane. That is, an orthogonal projection of the first strut onto the vertical centerline plane is substantially parallel to an orthogonal projection of the second strut onto the vertical centerline plane.
While the orthogonal projections are substantially parallel to each other, the first and second struts 170, 172 are not parallel in three dimensions because the struts cross over one another. In some embodiments, the struts cross over one another to form an angle of between three and forty degrees. In some embodiments, an angle of between ten and twenty degrees is formed. The angle formed by the crossing over of the struts may be between twelve and eighteen degrees in some embodiments.
In some embodiments, the first and second struts contact each other at least at a crossover location, while in other embodiments, the struts are separated from one another. In embodiments where the struts are separated, orthogonal projections of the longitudinal axes of the first and second struts onto the vertical centerline plane may overlap, but the struts are thin enough to avoid contacting each other. For purposes herein, a strut longitudinal axis is defined as the centroidal axis of the strut.
The struts shown in
Various surfaces of the struts may be flat. For example, as can be seen in the cross-section of first and second struts 141, 142 of unitary strut 122 in
Any suitable material or materials may be used to form the lacrosse heads disclosed herein or components thereof. In some embodiments, a plastic suitable for use with injection molding may be used.
Table 1 below shows the results of a finite element analysis of deflections of models of three lacrosse heads. The model of the Optik Universal head does not include the strut arrangements disclosed herein, and the first material was modeled as Plastic A. The Crossing Struts head is modeled to include the struts and overall head arrangement as shown in
When comparing the head without the crossing struts to the head with the crossing struts, a significant difference in the displacement of the head in the y direction is noticeable when a pass or shot force is modeled. For example, the y-direction displacement of the head at the sidewall (transition point 212) is almost 20% when using the same material (−8.279 v. −10.275). The weight difference between the two heads when using the same material is attributable to an increased throat size of the modeled crossing struts head relative to the modeled non-crossing struts head.
The below chart shows the results of calculated stiffnesses based on physical measurements with an Instron® testing machine. The sidewall and scoop stiffnesses are significantly higher for the head with the crossing struts as compared to the head without the crossing struts that is made of the same material.
The above aspects and embodiments may be employed in any suitable combination, as the present invention is not limited in this respect.
Having thus described several aspects of at least one embodiment of this invention, it is to be appreciated that various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description and drawings are by way of example only.