US 3910578 A
A combination of polymeric resins, in amounts specifically chosen with reference to a required balancing of physical properties, is injection molded to provide an improved laminate body for use in athletic equipment of the class employed in playing games wherein a propelled object is moved about and the laminate body is subjected to high impact stress. Typical of an adaptation of the laminate body for such athletic equipment is its use in molding a racquet frame for a lacrosse stick. In this application, representative of several such applications, an extremely tough, thin outer skin of very high impact resistance encloses a relatively low density foamed structure capable of imparting a pronounced degree of rigidity throughout the laminate body. Thus there is realized a low cost, light weight lacrosse stick of unusual durability and excellent handling characteristics, and the racquet head is not readily deformable by normal player pressure.
Claims available in
Description (OCR text may contain errors)
United States Patent Brine, Jr. Oct. 7, 1975 LACROSSE STICK  ABSTRACT  Inventor: William H. Brine, Jr., 26 Gypsy A combination of polymeric resins, in amounts specifi- Trail, Weston, Mass. 02193 cally chosen with reference to a required balancing of  Filed: Feb. 28, 1974 physical properties, is in ection molded to provide an improved laminate body for use in athletic equipment ] Appl. No.: 446,668 of the class employed in playing games wherein a propelled object is moved about and the laminate body is I Related Apphcatmn Data subjected to high impact stress. Typical of an adapta-  of 253,061 May 1972' tion of the laminate body for such athletic equipment abandoned is its use in molding a racquet frame for a lacrosse stick. In this application, representative of several  273/96 273/73 273/DIG' such applications, an extremely tough, thin outer skin Int Cl 2 of very'high impact resistance encloses a relatively low density foamed structure capable of imparting a  Field of Search 273/96 3 2 g nounced degree of rigidity throughout the laminate 1 /5 body. Thus there is realized a low cost, light weight 56 R f d lacrosse stick of unusual durability and excellent han- 1 e erences dling characteristics, and the racquet head is not UNITED STATES PATENTS readily deformable by normal player pressure.
364,596 6/1887 Lucem 273/73 C The moldEd Structure further includes a reinforced 3,306,960 2/1967 weissman 273/82R head Section in which lacing Strings are protectively 3,507,495 4/1970 Tucker 273/96 D t d d t d f t t d d b] 3,644,168 2/1972 Bonk 273/73 F am Prev 6 mm earmg 6 OTHER PUBLICATIONS The Sporting Goods Dealer, Dec. 1971, p. 140.
Primary ExaminerRichard C. Pinkham Assistant Examiner-Marvin Siskind Attorney, Agent, or Firm-Munroe l-l. Hamilton walls joined to the reinforced head are formed of a j-shaped cross sectional configuration which provides for improved handling of a lacrosse ball. Replacement of the lacrosse stick handle is facilitated by fastening means located in a recessed position which affords convenient accessibility.
4 Claims, 7 Drawing Figures US. Patent Oct. 7,1975 Sheet 1 of 2 3,910,578
US. Patent Oct. 7,1975 Sheet 2 of2 LACROSSE STICK This invention relates to a novel laminate body for use in athletic equipment of the class employed in playing games wherein a propelled object is moved about and the laminate body is subjected to high impact stress.
The extremely rough playing conditions'usually occurring during a game of lacrosse results in lacrosse racquet frames made of wood being subject to frequent breaking, deformation, or other damage, and various proposals have been made to strengthen the lacrosse racquet frames and render them more satisfactory in use. One such proposal has been to replace the open or hooked frame arrangement earlier used with a closed frame of wood or other material as disclosed in US. Pat. No. 2,142,527. Another proposal has been to substitute a plastic material for wood and to cast liquid elastomers such as a urethane elastomer in a desired structural form as has been more recently disclosed in US. Pat. No. 3,507,495.
However, in addition to the problem of rough usage to which all lacrosse sticks and their racquet frames are subjected, there is further imposed the necessity for containing net lacing without tearing out and for main taining the construction of the lacrosse stick within dimensional limits required by official lacrosse rules as made by National Lacrosse Rule Committees. For example, the transversely disposed section of the lacrosse racquet frame, commonly referred to as the head is required to have an inside measurement of between 7 inches and 12 inches.
The double wall sections of the racquet, recently declared legal by the Lacrosse Rules Committee, is required to be of a length of approximately 18 inches from the right angle end of the head to the handle. In addition, the wall sections shall not be over 2 inches in height. The rules also specify that the net or pocket of stringing must have a pocket sag such that the top surface of a lacrosse ball placed in the pocket will not drop below the bottom edge of the wall and the ball itself must be of a white or orange rubber, having a circumference of between 7 inches and 8 inches, a weight of from ounces to 5 /2 ounces, and which bounces, when dropped on a hardwood floor, from a height of 72 inches, a distance of from 45 inches to 49 inches.
Because of these limiting conditions, it is very difficult to find in any one material all of the properties required for a lacrosse stick, and there continues to be a need for a more satisfactory lacrosse construction which can be made within the confines of the specifications noted, and yet provide a maximum of strength, playability and wear resistance.
It is a chief object of the invention to cope with the problem indicated and to provide an improved lacrosse stick construction whereinseveral materials are combined and injection molded to form a lacrosse stick which fully complies with Rule Comittee requirements and in which there is realized to a maximum degree a combination of light weight, rigidity without brittleness and a high degree of resistance to deformation from player pressure.
It is also an object of the invention to devise a structural configuration in which the head of the lacrosse stick is reinforced in a novel manner such that not only is the head strengthened, but the stringing which is passed through the head portion is protectively contained in a desirable manner.
Still another object is to provide a double wall type lacrosse stick in which the wall members have an inverted J configuration which allows the ball to be trapped in the pocket and yet as the pocket is broken in or stretched, the ball is not subject to deflection by a lower ridge portion such as would be the case with the bottom edge on a concaved surface.
Still another object is to devise a fastening arrangement for replacement of lacrosse stick handles in a convenient and rapid manner. a
The nature of the invention and its other objects and 1 novel features will be more fully understood and appreciated from the following description of a preferred embodiment of the invention selected for purposes of illustration and shown in the accompanying drawings, in which:
FIG. 1 is a plan view of a lacrosse stick racquet frame with a handle portion of the stick being indicated fragmentarily;
FIG. 2 is a side elevational view of the lacrosse stick shown in FIG. 1;
FIG. 3 is a cross section taken on the line 33 of FIG. 1;
FIG. 4 is a cross section taken on the line 4-4 of FIG. 1;
FIG. 5 is an enlarged detail section of a portion of the racquet further indicating a reinforcing rib and recessed lacing surface;
FIG. 6 is a detail cross sectional view of a modified handle mounting, and
FIG. 7 is a cross section taken on the line 77 of FIG. 6.
Having in mind the problems and requirements inhcrent in the construction of a lacrosse stick, as noted above, I have conceived of a composite polymer structure in which two different polymers of thermoplastic type are combined together with stiffening fibers, a blowing agent, and a filler, to provide a foamed laminate body. A basic inventive concept is to control the components in such a way as to obtain a balanced combination of extreme toughness, pronounced rigidity, and resistance to breaking without brittleness, and this I find may be accomplished by utilizing a proper polymer mix, limiting the degree of foaming and regulating the amount of fiber stiffening induced.
In accordance with the invention, I provide a lacrosse stick racquet frame consisting in a laminate body having a tough stress crack resistant outer skin which is formed of the components noted. Associated with this tough outer skin is a foamed inner mass consisting in an internally stiffened cellular structure which functions to rigidly suport the tough outer skin against deformation forces within limits capable of being controlled to permit retention of a high degree of outer skin toughness and rigidity and yet avoiding risk of brittleness by reason the very small degree of yieldabilitypermitted by the cellular structure under bending stresses.
In thus supporting a tough outer skin with an internally stiffened cellular structure, I find that I may advantageously employ a thermoplastic polymer referred to as an ionomer. An ionomer may be defined as a polymer consisting of an alphaolefin type copolymer containing ionized carboxylic acid groups and is characterized by an unusually high melt strength in a foamed structure. I may also combine with the ionomer polymer a modifying polymer consisting in a nylon polymer such as Ultramid, 8-3 Natural, manufactured by Basf Wyandotte Company, and this polymer provides additional toughening and stiffening properties in the laminate body.
I have further determined that by melting the two polymers together and at the same time combining stiffening fibers such as glass, and a blowing agent such as NaI-ICo, in carefully controlled amounts, I may thereafter cool or chill the melted mass while contained within desired molding surfaces to obtain a tough outer skin which is free from voids, and an internally stiffened cellular structure which has very small uniformly sized voids.
By controlling the amounts of the modifying polymer stiffening fibers and blowing agent in accordance with predetermined stresses or deformation forces, a material of suitable toughness, rigidity and freedom from brittleness is realized, well suited to use in a lacrosse stick as well as other athletic equipment including such items as shoulder pads, knee pads, field hockey sticks, bats, and the like.
As illustrative of one desirable procedure for making the composite plastic structure disclosed above, I may therefore carry out steps which include bringing together in a confined space a mixture of an ionomer polymer, a modifying polymer, a quantity of stiffening fibers and a blowing agent, heating the mixture to provide a melted laminate body wherein voids are formed internally by the blowing agent, chilling the laminate body to form a thin outer skin which is free from voids and controlling the quantity of modifying polymers, stiffener fibers and blowing agent, combined with the ionomer polymer to form an outer skin having a tough stress crack resistant surface, and to provide an internally stiffened cellular structure for rigidly supporting the tough outer skin against deformation forces to which athletic equipment of the class above-indicated may be exposed.
As an example of specific materials for use in making a lacrosse racquet frame, I may employ an ionomer polymer such as Surlyn A, manufactured by the E. I. Dupont de Nemours Co., Inc. of Wilmington, Delaware. With the Surlyn, may be combined a nylon such as Ultramid, B-3 Natural, manufactured by Basf Wyandotte Co., and having a common melting point range with Surlyn A of from 400 to 450 F. A suitable stiffening fiber may consist of glass fiber, as well as fibers such as asbestos fibers and titanium fibers.
It should be observed that in using stiffening fibers, care must be exercised in not employing a quantity which will result in brittleness relative to the impact resistance required in a lacrosse racquet frame. I have found that for some sizes of lacrosse sticks such as those used by offensive lacrosse players, I must limit the quantity of glass fibers within a percentage range by weight from about percent up to about 10 percent of the total mixture. This range I further find may vary slightly when larger sizes of lacrosse sticks are employed, for instance, lacrosse stick frames used by defensive players, and particularly goalies, where the percentage of glass fibers can be increased upwardly by a small degree but not exceeding percent by weight of the total mixture.
Similarly, I have determined that the blowing agent must be limited quite sharply to maintain a suitable degree of rigidity in the foam structure without causing excessive brittleness and in this respect, having regard for the brittleness factor in relation to a lacrosse frame, I find that the percentage of blowing agent must be held within a range of 1 percent to 3 percent.
One desirable formulation for a smaller size of lacrosse stick in specific quantities may, for example, be as follows: 67 percent Surlyn A. 10 percent glass fiber, 20 percent Ultramid, 2 percent filler titanium dioxide, and 1 percent blowing agent NaI-iCo Referring to the drawings, FIGS. 1 and 2 illustrate a lacrosse stick made from a foamed laminate material of the type above disclosed. As shown therein, numeral 2 denotes a lacrosse stick handle, usually of wood, at one end of which is supported a lacrosse racquet frame made up of a throat portion 4, a head portion generally denoted by arrow 6, and a pair of spaced side wall portions 8 and 10 extending between the head portion and the throat in converging relationship. Supported within the frame described is a net 12 consisting of interwoven lacing of raw hide or other material, and having formed therein a ball-receiving pocket 14 located adjacent to the throat portion 4, as susggested in FIG. 1.
As earlier described, the entire laminate frame is preferably made by an injection molding operation utilizing suitable forming surfaces, as shown, to provide the desired shape indicated in the drawings, and the molded material, for example, having a formulation such as that specified above, is heated in a temperature of from 400 to 450 F. Thereafter, the molded surface is chilled or cooled to provide throughout the racquet frame a composite body which includes a thin outer skin, denoted in the drawings by numeral 16, best shown in FIGS. 4 and 5, and an internally stiffened cellular structure 18 which is also indicated in FIGS. 4 and 5 and is characterized by voids of a relatively minute uniformly-shaped size.
The racquet frame thus constructed is of a relatively light weight and is, more importantly, of a pronounced rigidity such that it is capable of resisting deformation by pressures normally exerted by lacrosse players and can only be deformed by being subjected to unusually heavy bending forces such as are not ordinarily encounted in lacrosse play.
It is again pointed out that the internally stiffened cellular structure 18, with its very small and uniform void composition functions to help provide a necessary rigidity in the frame. Yet by being yieldable to a very slight degree because of the foamed composition, the cellular structure prevents brittleness and serves to resist breaking under the impact forces usually exerted in lacrosse play.
It should also be understood that the extreme toughness of the outer skin 16 not only resists cracking or breaking when subjected to high impact forces, but also is capable of defining lacing holes in the frame such as has been indicated in FIG. 2 of the drawings at 10a, 10b, 10c and 10d, of a high tear resistant nature. It will be understood that sudden impact of a solid lacrosse ball against the lacing may impose quite heavy tearing stress, and the combination of reinforced cellular structure and outer toughened skin, has been designed in the present invention-to withstand such stresses.
In my improved lacrosse stick construction shown in the drawings, I have also devised structural improvements in the racquet frame itself and these structural improvements are introduced at the head portion, also the side walls and the throat.
Attention is directed to FIG. 4, for example, where l have illustrated specially formed inner side wall sur faces 20 and 22, which are especially molded in the shape of an inverted J to provide upper curved ball trapping portions 20a and 22a, and these ball trapping portions merge with lower substantially straight ball releasing surfaces 20b and 22b. In shaping the upper inverted J-shaped surfaces, I have also formed these surfaces so as to provide an arc of curvature which corresponds to the arc of curvature of a standard lacrosse ball, earlier specified. It is pointed out that by means of this arrangement, the upper inverted J surfaces 20a and 22a may, at certain points in a ball trapping operation, be fully in contact with the peripheral surface of the lacrosse ball when it is trapped in the pocket 14 of the net 12. There may thus be realized better ball control by the lacrosse player.
In addition, the frame structure shown in FIGS. 1, 2 3 and 5 has its head portion 6 specially constructed with a reinforcing rib part 6a which is located intermediately of inner and outer edges of the head. This rib portion 6a functions to impart a substantially increased rigidity in the head, resulting in better durability and playing characteristics at points where a great deal of bending stresses are encountered in lacrosse play.
In conjunction with the reinforcing rib 6a, I have also provided a relieved under surface 6b which extends inwardly of the head portion of the frame to define a recessed net lacing surface through which laces may be passed and contained in a protected relationship such that when the frame is slid along the ground in scooping up a ball, the laces are protected against abrasion and wear such as may normally take place in a conventional frame.
At the opposite end of the frame, the thread portion 4 has been redesigned to fonn a handle socket 2a into which the handle 2 may be inserted and detachably secured in place by a screw fastening as 24, and the underside of the throat is relieved to contain the fastening head in a conveniently recessed manner. This arrangement provides for rapid and simple replacement of a broken handle by a player, and the extended socket functions to retain the handle end in a solidly secured manner.
1. A lacrosse stick comprising a closed frame having a throat portion, a handle attached to the frame adjacent to the throat portion, a net supported between the sides of the frame and having a ball-containing pocket extending forwardly of the throat portion of the frame, said frame including a transversely disposed head portion and a pair of side wall portions extending between the head portion of the said throat portion, and each of said side walls being shaped to provide a cross section in the form of an inverted J, thereby to furnish an upper curved ball-trapping edge and lower relatively straight pocket guiding surfaces.
2. A structure according to claim 1 wherein sai transversely disposed head portion is of a generally dish-shaped cross section and presents an inwardly inclined upper surface along which a lacrosse ball may be scooped up and guided into the net and the underside of said head portion is formed with an intermediately located reinforced rib portion and a relieved surface extending inwardly therefrom to constitute a lacing protective recess.
3. A structure according to claim 1 wherein said frame is recessed to form a handle aperture extending rearwardly from the throat portion and fastening means are transversely located through the bottom of the frame and engage the handle.
4. A structure according to claim 3 in which one side of the throat portion is recessed to define a fastening surface through which the said fastening is driven.