1. Field of the Invention
The present invention relates generally to sports equipment and more particularly, to an improved shaft lock for interconnection between the handle and head of a lacrosse stick.
2. Description of the Background
In 1970, the introduction of double-wall, synthetic lacrosse heads revolutionized the game of lacrosse. In comparison to the traditional wooden single-wall heads, the synthetic heads imparted a lightness, maneuverability, and flexibility never-before experienced by lacrosse players. These performance advantages greatly enhanced players' skills such as throwing, catching, cradling, and scooping, and brought the sport of lacrosse to new levels of speed and excitement.
FIG, 2 illustrates a conventional injection molded goalie head comprising the same components as a field player's lacrosse stick illustrated in
The typical features of a lacrosse stick are shown generally in Tucker et al., U.S. Pat. No. 3,507,495, Crawford et al., U.S. Pat. No. 4,034,984, and Tucker et al., U.S. Pat. No. 5,566,947, which are all incorporated by reference herein.
The traditional double-wall synthetic head is an injection-molded, monolithic structure. Examples of suitable synthetic materials well known in the art include nylon, polypropylene (PP), polyethylene (PE), amorphous polar plastics (e.g., polycarbonate (PC)), polymethylmethacrylate (PMMA), polystyrene (PS), high impact polystyrene (HIPS), polyphenylene oxide (PPO), glycol modified polyethylene terphthalate (PETG), acrylonitrile butadiene styrene (ABS), semicrystalline polar plastics (e.g., polyester PET and PBT), polyamide (e.g., Nylon 6 and Nylon 66), urethane, polyketone, polybutylerie terephalate, acetals (e.g., Delrin™ by DuPont), acrylic, acrylic-styrene-acrylonitrile (ASA), metallocene ethylene-propylene-diene terpolymer (EPDM) Nordel™ by DuPont), and composites. When first introduced, these materials were clearly superior to wood, offering players improved handling and durability. For example, a lacrosse head constructed of DuPont™ ZYTEL ST 801 nylon resin is able to withstand the bending and harsh impacts inherent to competition far better than a traditional wooden stick. As another example, a polycarbonate head, though having a flexibility similar to that of wood, is more structurally durable than wood and much lighter and, therefore, easier to maneuver when attached to a handle.
Ever since the plastic head was incorporated on competition lacrosse sticks in the I 970s, the plastic head has been attached to the handle with a simple screw connection, e.g., a “self-tapping” screw through the plastic head and handle (self-tapping screws cut their own threads).
The durability of that connection has long been an issue for several reasons. Repeatedly removing and re-assembling the components will eventually strip the hole and prevent stable assembly. In addition, the stresses on competition lacrosse sticks during play weakens the conventional connection inevitably to the point where the head sometimes loosens or even dislodges from the handle during play. Loosening or dislodgement can occur as the screw unscrews as a result of vibration, or as a result of the threads of the screw stripping from torque or other stress when no other forces are brought to bear to prevent these occurrences. The problem has grown acute due to the increasing use of lighter and thinner-walled handles. The thread engagement is often limited to two or fewer threads, causing excessive stress and instability of the head/handle connection. Stripping and loosening of the head/handle connection results. Further, when the handle is impacted, as frequently occurs during competitive play, the walls can compress or expand and the screw threads can strip. To combat these issues, players often resort to taping over the head/handle connection, but tape adds weight and is only a temporary fix, at best. Finally, like all athletes, lacrosse players are bigger and stronger than they have ever been, so pressures on the screw connection are increasing from the increased torque applied by stronger players.
Previous efforts to solve the head/handle connection problem have been ineffective. For example, U.S. Pat. No. 8,052,549 to Sykora discloses a non-resilient plug-like insert with a magnet for insertion into the handle. But the Sykora insert adds excessive weight and does not remain securely in position. Other advertised inserts devised for this same purpose have been of different constructions from the device disclosed by the Applicant and due to those constructions fail to satisfy the need for a more robust interconnection for the handle and head of a lacrosse stick to avoid loosening and head rattle.
References in this application to “competitive play”, “competitive sticks” and the like refer to lacrosse games and sticks that are subject to a governing body set of rules and regulations, such as the NCAA for men's lacrosse, US Lacrosse for women's lacrosse, the National Federation of State High School Association for much of high school lacrosse and variations adopted by individual private school and recreational leagues. Such terms do not refer to articles that have some or all of the basic components of lacrosse sticks (e.g. STX “Fiddle STX”) but which, due to their overall size, durability, etc. are not intended for use in competitive play.
It is, therefore, an object of the invention to provide a robust, dual-material connection mechanism for the handle and head of a lacrosse stick that employs a hard plastic (e.g., Nylon) screw-anchor embedded in an elastomeric body that fits snugly within various inner handle dimensions.
It is another aspect of the present invention to provide a connection mechanism for the handle and head of a lacrosse stick, that employs a collared male plug affixed to the lacrosse stick head and adapted to fit within the hollow bore of a lacrosse stick shaft. Both embodiments of Applicant's device and all other devices intended for the purpose of securing a lacrosse head/handle connection are hereinafter referred to as a “shaft lock.”
In accordance with the foregoing objects, the present invention is an improved shaft lock for interconnection of an elongate tubular lacrosse handle and a plastic head. In a first preferred embodiment, the shaft lock comprises an elastorneric insert compression-fitted inside the handle. The insert has a compressible body portion which, in an uncompressed form, generally conforms to the interior walls of the handle and is defined by a plurality of co-planar ribs that span the interior walls of the handle. A rigid screw-anchor is embedded within the elastomer insert, and the insert is anc hored inside the handle by at least one screw threaded through the handle into the screw-anchor from top-to-bottom, the screw(s) engaging the screw anchor and compressing it against the elastomeric insert. The threaded engagement of the screw(s) through the wall of the handle and into the screw-anchor compresses the elastomeric insert, maintaining a constant tension against the screw(s) and against the interior walls of the handle. The screw-anchor optionally has a metal nut component to accommodate the screw(s). This interaction avoids loosening and/or dislodgement of the screws as a result of impact or vibration, and keeps the threads of the screw from stripping either the handle walls or the insert as a result of torque or other stress.
Further, the forces brought to bear by the compression of the plastic head onto the handle during assembly contribute to a more secure engagement since the head is attached to the handle over the handle segment containing the above-described attachment mechanisms.
In a second preferred embodiment, the shaft lock comprises a collared male plug integrally formed with a lacrosse head for joining the head to a hollow lacrosse stick shaft. The male plug is adapted to fit within the hollow bore of the lacrosse stick shaft. The male plug includes compressible members (e.g., ribs) that provide a snug friction fit with shafts having a range of different bore dimensions. In one preferred embodiment, the male plug includes a snubbed collar around the male plug that creates a gap between the collar and the male plug. This gap receives the wall of the lacrosse stick handle. To further secure the shaft, a fastener is preferably placed through an opening in the collar. Optionally, the shaft and possibly also the male plug have openings to receive the fastener, which are aligned with the opening in the collar.
In this configuration, the shaft is held securely in place by the friction fit of the male plug, the friction fit of the collar, and the fastener. The collared male plug therefore provides a significantly stronger connection in comparison to the simple male plug connections suggested by the prior art. In addition, the snubbed collar allows a player to place his hand closer to the center of gravity of the lacrosse head and ball, providing a better feel for stick handling and ball control.
In this second preferred embodiment, the compressible members on the male plug also provide a significant benefit. Many players purchase lacrosse stick shafts and heads independently and assemble custom sticks. For example, a player may prefer the head of one manufacturer and the shaft of another manufacturer, for cost or performance reasons. Players also frequently break lacrosse stick shafts and must replace them with different models or makes. To promote as many sales as possible, manufacturers tend to use uniform dimensions of the outside diameters of shafts and the corresponding female connections on the lacrosse heads. However, the inside dimensions of shafts can vary widely, due to different wall thicknesses, geometries, and shaft materials. For example, a titanium shaft would have a thinner wall than an aluminum shaft. The compressible members on the male plug help accommodate these varying inside shaft dimensions.
The present invention is described in greater detail in the detailed description of the invention, and the appended drawings. Additional features and advantages of the invention will be set forth in the description that follows, will be apparent from the description, or may be learned by practicing the invention.
Other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments and certain modifications thereof when taken together with the accompanying drawings in which:
Reference will now be made in detail to preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
The present invention is a shaft lock for interconnection between an elongate tubular lacrosse handle and a plastic head having a frame with a socket for insertion of the handle.
The elongate tubular lacrosse handle 20 may be any conventional tubular lacrosse handle such as a traditional octagonal cross-section formed of aluminum or composite materials. The plastic head 10 (see
The shaft lock 2 has an elastomeric compressible body portion 12 which, in an uncompressed form generally conforms to the interior walls of the handle 20 and is sized for a close compression fit. A screw-anchor block 14 is embedded within the elastomeric body portion 12, and the shaft lock 2 anchors the handle 20 inside the socket by at least one and preferably two screws 22 threaded through the socket and handle 20 and into the anchor block 14 from top-to-bottom. The screw(s) 22 engage the anchor block 14 and compress it and the elastomeric body portion 12. The threaded engagement of the screw(s) 22 into the screw-anchor block 14 in combination with the resiliency of the elastomeric body portion 12 maintains a constant tension against the screw(s) 22. This avoids loosening and/or dislodgement of the screws 22 as a result of impact or vibration, and keeps the threads of the screw(s) 22 from stripping either the handle wall(s) or the insert as a result of torque or other stress.
As seen in
Referring back to
If desired, the screw(s) 22 may be extended to engage nuts 33 at the bottom of anchor block 14. The combination of a threaded engagement of the screws 22 through handle walls 10 and through shaft lock 2, plus the compressive force of the screws 22 biasing the shaft lock 2 against the handle 20, effectively provides a more stable reinforcing collar inside the handle 20 along the distal tip that is inserted into the head. This helps to avoid loosening and/or dislodgement as a result of impact or vibration, and resists the threads of the screw stripping either the handle walls or the insert as a result of torque or other stress. Moreover, the receptacles 42 of the Nylon anchor body 14 have a high coefficient of friction and prevent counter-rotation and loosening of the screws 22. The machine screw(s) 22 can be conventional self-tapping screw(s) of a length calculated to extend at least partially through a majority of the anchor body 14 from top-to-bottom.
To assemble the shaft lock 2 according to this first embodiment of the present invention, the shaft lock 2 is placed inside the handle 20 with its through-bores 44 in axial alignment with both mounting holes in the handle 20 (as conventionally provided on commercial lacrosse stick handles). The lacrosse handle 20 is then inserted inside the socket of the head. The user inserts the screw(s) 22 through one wall of the socket of the head, and begins to thread it through the underlying wall of the handle 20 and into the shaft lock 2 using an appropriate implement such as a screw-driver or hex key. Tightening continues (optionally through the opposing wall of the handle 20), and through the other wall of the socket of the head 10, again optionally employing a nut beneath anchor block 14 as an anchor.
The foregoing securement of head to the handle 20 maintains a constant compressive force against the interior walls of the handle 20. This avoids loosening and/or dislodgement as a result of impact or vibration, and resists the threads of the screw stripping either the walls or the insert as a result of torque or other stress.
Another embodiment of to shaft lock according to the present invention comprises a collared male plug shown with reference to
As best seen in
The illustrated core 801 is defined by a tubular outer wall 802. As seen in
According to a preferred embodiment of the present invention, collar 807 is approximately 0.712 inches long and male plug 801 is approximately 1.950 inches long. Core plug 801 is preferably about 0.874 inches wide as measured at maximum lateral width and about 1.062 inches wide as measured at maximum vertical width. The short length of collar 807 allows a player to hold shaft 20 as close as possible to the center of gravity of head 10 and a ball inside head 10. The preferred dimensions and shapes of male core plug 801 and its lobes 803 help maximize the strength of the connection between lacrosse head 10 and shaft 20. The compressible lobes 803 facilitate a tight friction fit inside shaft 20. In addition, compared to a solid plug fitted into the bore of shaft 20, the compressible lobes 803 and the shape of core plug 801 help reduce the weight so as not to affect the center of gravity of the overall head 10. For additional strength, the thickness of the stop member in throat area 12 can also be increased to, for example, 0.235 inches. Core 801 according to this embodiment of the present invention may be either permanently affixed to or integrally formed with lacrosse head 10 to enable head 10 to be securely attached to various shapes and sizes of lacrosse stick shafts 20, such as octagonal, such as tear-drop, asymmetrical, and oval shaped sticks. Alternatively, core 801 may be removable from head 10 to provide even more customization for players wishing to attach different sizes and types of lacrosse heads to different sizes and shapes of lacrosse stick shafts with a secure plug connection, and to have such connections be interchangeable as between various sizes and types of sticks and shafts as the player grows, changes abilities, preferences, or positions on the team. For this purpose, the collared male plug 8 inclusive of both core 801 and collar 807 according to the present invention may be manufactured in different diameters and/or with different numbers of points as described herein, or may be manufactured in a single, “standard” size and shape designed to be adaptable for use with many of the variations of head and shaft shapes described above.
Further, and as best shown in
The additional connection between head 10 and shaft 20, side screw hole 805, is also shown in
Thus, to assemble, the lacrosse stick shaft 20 is inserted into the gap 812 between collar 807 and the base of core plug 801. Upon insertion, the end of shaft 20 abuts the bottom of the gap 812 between core plug 801 and collar 807. Then, screws 809 and side screw (not shown) may be inserted through screw holes 806/808 and 805, respectively, and through corresponding holes in shaft 20, to secure shaft 20 to head 10. Core plug 801 thus extends inside shaft 20 and down a portion of the length thereof, wherein points 803 provide a snug fit between core plug 801 and the interior surface of shaft 20. Alternately, in an optional embodiment wherein core plug 801 is not integrally formed with head 10, core plug 801 may be inserted into the hollow interior of shaft 20 and secured therein with a screw 809 placed through side screw hole 805 and a corresponding screw hole on the shaft 20 (not shown). Then, shaft 20, with core plug 801 secured in the interior of the end thereof, may be inserted into the recess formed in head 10 by integrally formed collar 807 and secured therein by screws 809 inserted through collar 207 (through screw hole 808), shaft 20, and core plug 801 (through screw hole 806) to secure head 10, shaft 20, and plug 801 together.
The foregoing disclosure of embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many variations and modifications of the embodiments described herein will be obvious to one of ordinary skill in the art in light of the above disclosure. The scope of the invention is to be defined only by the claims, and by their equivalents.
CROSS-REFERENCE TO RELATED APPLICATION(S) The present application derives priority from U.S. provisional application Serial No. 62/107,693 filed 26 Jan. 2015, and is a continuation-in-part of U.S. patent application Ser. No. 14/270,790, filed 6 May 2014, which is a continuation in part of U.S. patent application Ser. No. 13/561640, filed 30 Jul. 2012,
Number | Date | Country | |
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62107693 | Jan 2015 | US |
Number | Date | Country | |
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Parent | 14270790 | May 2014 | US |
Child | 15006853 | US | |
Parent | 13561640 | Jul 2012 | US |
Child | 14270790 | US |