WO2009134974A1

WO2009134974A1 - Tie-off device for a string of a sporting racket

Info

Publication number: WO2009134974A1
Application number: PCT/US2009/042256
Authority: WO
Inventors: David A. Schwartz; Charles P. Hines, Jr.; Christian P. Hines
Original assignee: Schwartz David A; Hines Charles P Jr; Hines Christian P
Priority date: 2008-05-02
Filing date: 2009-04-30
Publication date: 2009-11-05

Abstract

A tie-off device (110, 210, 310, 410) for a string of a sporting racket having peripherally located string grommets (132, 232, 332, 432) through which racket string is pulled, comprising a base portion that attaches to a frame of the sporting racket proximate at least one string grommet; at least one surface projection (114, 214, 314, 414) (e.g., an offset surface projection relative to a central portion of the device) that extends away from the base portion and around which a knot (138, 238, 338, 438) is made using the string, so that the projection anchors the knot to resist movement of the string through the at least one string grommet, and the string is thereby tied-off to a structure other than itself.

Description

TIE-OFF DEVICE FOR A STRING OF A SPORTING RACKET

CLAIM OF BENEFIT OF FILING DATE

[0001] The present application claims the benefit of the filing date of U.S. Provisional Application Serial No. 61/049,811 (Filed May 2, 2008), and the entirety of the contents of this application being hereby expressly incorporated by reference.

FIELD OF THE INVENTION

[0002] The present invention relates generally to sporting rackets, and more particularly to an improved approach to stringing sporting rackets.

BACKGROUND OF THE INVENTION

[0003] Globally, racket sports (including tennis, squash, badminton, and racketball) continue to enjoy widespread popularity. Each year millions of rackets are manufactured and sold. As is known, rackets include a frame that is configured to hold a woven configuration of racket string (e.g., a solid core filament with one or more outer filament wraps, a multifilament structure with or without one or more outer filament wraps, a composite string including a combination of two or more different materials, or any combination). The racket string (e.g., a string of natural or synthetic material, typically having a cross -sectional diameter from about 14 to about 20 gauge (e.g., 15 to about 18 gauge) or about 0.8 to about 1.7 mm) is pulled in tension for generating a taut hitting surface due to the spaced woven structure. The spacing of strings also allows air to pass during a user swing. In conventional rackets, the woven structure includes longitudinally oriented strings (i.e., the main strings) and transversely oriented strings (i.e., the cross strings).

[0004] The stringing of rackets is generally performed manually through a series of steps that include providing a string set (e.g., one or two coils of string about 10 meters in total length). A racket frame is mounted to a stringing machine. The main strings are threaded into the racket through holes disposed about the periphery of the racket frame. The holes may be lined with a grommet or a strip of grommets, through which the strings also pass.

[0005] A series of steps ensue that include clamping the string, pulling the clamped string to a predetermined tension, clamping the string just pulled, threading and pulling the next string (e.g., the adjoining main string), and so on, until all of the main strings are in place. At that time, it is common to tie-off the end of the string set, thereby substantially preserving the pulled tension. The tie-off typically involves inserting the string through a hole and knotting it around and in direct contact with an already pulled string.

[0006] A weave process is performed to string the cross strings, with tensioning and clamping similarly performed. Upon stringing the final cross string another tie-off occurs. Classic stringing techniques will typically result in two knots (e.g., a start knot and an end knot) to four knots (e.g., a pair of start and end knots) per strung racket. Additional knots are also possible, such as when stringing patches are employed to only partially replace a string job.

[0007] As can be appreciated, the string knots pose a location that results in a high frequency of breakage. Such breakage is often a result of one or more of local thinning of the tie-off string about which the knot is made (e.g., it is choked), abrasion resulting from the shear of the knot string about the tie-off string, shear forces from the knot, or any combination. Because of the location of the break, users tend to assign responsibility for the breakage to the person who strung the racket. This results in losses to the stringers, which often tends to extinguish any profitability to be realized from the stringing job. Accordingly, there is a need in the art for an improved approach to stringing rackets that reduces the frequency of string breakage at the tie- off knot. There also is a need in the art to continue the trend toward reduction of mass carried on a racket, as well as the need to evenly balance any mass added to the racket, to avoid interfering with the design intent of the racket. [0008] Examples of efforts to address stringing of rackets are illustrated in U.S. Patent Nos. 4,033,582; 4,747,598; 5,667,216; 5,993,337; 6,074,315; and 6,179,735, all incorporated by reference.

SUMMARY OF THE INVENTION

[0009] The present invention meets one or more of the above needs by providing a tie-off device for a string of a sporting racket having peripherally located string holes (e.g., including one or more grommets) through which racket string is pulled, comprising a base portion that attaches to a frame of the sporting racket proximate at least one string grommet; at least one surface projection (e.g., an offset surface projection relative to a central portion of the device, or a surface projection stacked on the base portion) that extends away from the base portion and around which a knot is made using the string, so that the projection anchors the knot to resist movement of the string through the at least one string grommet, and the string is thereby tied-off to a structure other than itself. As seen from the illustrations herein, the resulting knot can thus be free of any direct contact with a tie-off string, namely within the interior of the frame; the resulting knot does not require encircling the tie- off string so that it is effectively chokes the tie-off string, or both). [0010] The tie-off device may be further characterized by one or any combination of the following features: the base portion is configured to substantially surround the at least one string grommet; the base portion includes a centrally located opening that is generally axially aligned with the at least one string grommet toward the interior of the frame; the base portion is wider than it is tall; the base portion is wider toward its bottom than toward its top; at least one projection is a post having a free end; the at least one projection is connected at both of its ends to the base portion; the device includes a plurality of projections that extend from the base portion; the base portion is configured for resisting rotation about the at least one string grommet; the base portion includes an adhesive for bonding the base portion to the frame. The present invention also contemplates a sporting racket including the tie-off device of the present invention optionally including one or more of the above features. It also contemplates a method of stringing a sporting racket, comprising the step of tying off the racket string on the projection of the tie-off device of the present invention as described.

DESCRIPTION OF THE DRAWINGS

[0011] Fig. 1A is a perspective view of an illustrative tie-off device of the present invention.

[0012] Fig. 1 B is an overhead plan view of the device of Fig. 1A

[0013] Fig. 1 C is a side sectional view taken along line C-C of Fig. 1 B.

[0014] Fig. 1 D is a perspective view illustrating the use of the tie-off device of

Figs. 1A-1 C in a strung racket.

[0015] Fig. 2A is a perspective view of another illustrative tie-off device of the present invention.

[0016] Fig. 2B is an overhead plan view of the device of Fig. 2A

[0017] Fig. 2C is a side sectional view taken along line C-C of Fig. 2B.

[0018] Fig. 2D is a perspective view illustrating the use of the tie-off device of

Figs. 2A-2C in a strung racket.

[0019] Fig. 3A is a perspective view of another illustrative tie-off device of the present invention.

[0020] Fig. 3B is an overhead plan view of the device of Fig. 3A

[0021] Fig. 3C is a side sectional view taken along line C-C of Fig. 3B. [0022] Figure 3D is a perspective view illustrating the use of the tie-off device of

Figs. 3A-3C in a strung racket.

[0023] Figure 4A is a perspective view of yet another illustrative tie-off device of the present invention.

[0024] Figure 4B is an overhead plan view of the device of Fig. 4A

[0025] Figure 4C is a side sectional view taken along line C-C of Fig. 4B.

[0026] Figure 4D is a perspective view illustrating the use of the tie-off device of

Figs. 4A-4C in a strung racket.

DETAILED DESCRIPTION

[0027] With reference to the drawings, it is seen that the tie-off device of the present invention is generally configured to at least partially surround the tie-off string, to contact a racket frame and to provide a surface that is spaced away from the tie-off string so that the knot (and preferably also the tie-off device) has no direct contact with the tie-off string (e.g., within the racket frame interior). In this manner, it is believed possible that the problems previously faced with tie-off strings that are directly knotted can be avoided. The geometry and size of the tie-off device is also sufficient for avoiding interference with the performance characteristics of a racket. [0028] The manner of configuration of the tie-off device may vary but generally will include a base portion that at least partially surrounds the tie-off string and mounts in contact (either direct contact or via an intermediate layer, such as adhesive layer, a seal (e.g. a rubber o-ring seal) or both. The base portion will generally have a tie-off portion that, when the device is mounted against a frame (e.g., within the racket frame interior) about the tie-off string, locates a resulting knot in a position laterally offset from the tie-off string. For example, the tie-off portion may include a tie-off surface that is spaced at least about 1 mm, more preferably at least about 2 mm away from the tie-off string. The tie-off surface may be spaced less than about 20 mm, more preferably less than about 10 mm away from the tie-off string. The tie-off portion may have any suitable configuration. In a preferred embodiment, it includes a wall surface about which a knot can be formed while keeping the knot spaced from the tie-off string. The wall surface generally will have a substantially continuous contoured surface, a flat portion or both. It may have a generally cylindrical portion, the cylindrical portion having a longitudinal axis. The tie- off portion may have a free distal end. The tie-off portion may be part of a continuously integral structure relative to the base portion (e.g., it may define the generally cylindrical portion as part of open loop. Tie-off portion may be free contact with tie-off string in a strung racket, at least within the interior space of the racket frame.

[0029] It will be appreciated that the surface of the tie-off portion may be prismatic (e.g., it may be prismatic with rounded edges). The dimensions and geometry of the tie-off portion may be substantially continuous, or it may vary along its longitudinal axis. The existence of a longitudinal axis likewise is not intended to limit the configuration. The tie-off portion may be generally arcuate or have one or more longitudinal axes.

[0030] The tie-off device of the present invention may be made in any suitable art-disclosed manner. For example, they may be made from molding (e.g., injection molding, compression molding, rotational molding, blow molding), casting, layer-by- layer buildup, extruding, pultruding, thermoforming, or any combination thereof. It is contemplated that the tie-off device will include a polymeric material. One or any combination of a polymeric material may be employed as the entirety or a portion of the tie-off device of the present invention, such as a material selected from polyethylene, polyethylene terephthalate, polycarbonate, or some other polyester, polyvinyl chloride, polystyrene, styrene acrylonitrile, acrylonitrile butadiene styrene, a methacrylate, an acrylate, polysulfone, polypropylene, polyamide, polyimide, silicone, polytetrafluoroethylene, polyurethane, polylactic acid, polyepoxide, thermoplastic polyolefin or some other elastomer, or any combination (including but not limited to blends and/or copolymers) thereof. The material may be prepared from a post- consumer recycled plastic.

[0031] The polymeric material used to make the tie-off device may have one or more of a durometer (Shore D) hardness [per ASTM D2240] of at least about 30, more preferably at least about 40, still more preferably at least about 50, and more preferably at least about 60, and still more preferably at least about 70, a flexural modulus [per ASTM D790] of at least about 35 MPa, and more preferably at least about 70 MPa, an Izod impact strength (at 23⁰C) [per ASTM D256 method A] of at least about 15 J/m, more preferably at least about 35 J/m, still more preferably at least about 70 J/m, and possibly as high as at least about 150 or 300 J/m. The polymeric material used to make the tie-off device may be amorphous or at least partially crystalline. It may be filled or unfilled (e.g., with a mineral filler (which may itself be in a nanoparticle form) such as talc, clay, mica or the like). The polymeric material may be fiber reinforced (e.g., glass-fiber reinforced, natural fiber reinforced). Unless otherwise stated or required by the referenced test standard, all properties are measured at a temperature of about 23°C. The material may include one or more other additives such as a thermal stabilizer, a light stabilizer, a processing aid, a colorant or any combination thereof. Unless otherwise stated, all test methods are the method employed as of the filing date hereof in which first set forth. [0032] It is possible that the tie-off device herein may be made from a metal, a ceramic or it may be a composite). It is also possible that the device will include a plurality of materials each having a different properties. For example, a rigid metal (or other material) ring might be insert molded or embedded within a softer material or plural layers may adjoin each other. The knot may bear against the softer material and possibly even cause the softer material to elastically and/or plastically deform, while preserving the inner material in tact.

[0033] With specific reference to the drawings of Figs. 1A-4D, there are depicted various possible embodiments within the scope of the present invention. The embodiment of Figs. 1A-1 D illustrates one illustrative tie-off device 110 of the invention, pursuant to which a base portion 112 supports a surface projection 114 (e.g., a post) that extends away from the base portion and terminates at a free end 116. In the embodiment shown, the surface projection 1 14 is depicted as being located toward an end 118 of the device 110, and projecting at an angle (a), which is generally less than 90°, and more preferably from about 30 to about 60° (e.g., about 40 to about 50°). It is also possible that the surface projection is located at a generally central portion of the device. It is also possible that more than one surface projection is used (e.g., a projection on opposite sides of the device). The surface projection may have a substantially constant peripheral cross-section along the projection. As shown, the surface projection has a peripheral cross section that varies along its length. Specifically, there is shown a neck region 120 having a diameter (or other outer peripheral surface dimension) that is smaller than the diameter (or other outer peripheral surface dimension) at the free end, or elsewhere along the length of the projection. In the base portion 112 of the device, there is defined a through hole 122 or other suitable opening. Though shown in Fig. 1 C as possibly having an undercut 124 that affords a varied profile, such a feature may be omitted.

[0034] The device of this embodiment is depicted as having a generally elliptical bottom on the base portion 112. Other geometries are possible, and may include arcuate shapes (e.g., a generally circular geometry) that are free of any corners, geometric shapes (e.g., polygonal) having one or more corners, or a combination. Though other geometries are possible, preferably the largest dimension of the base portion (e.g., the length (L) of the base portion) is larger than the height (H) of the device at its tallest portion. For example, preferably the largest dimension of the base portion (e.g., the length (L) of the base portion) is larger than the height (H) of the device at its tallest portion by a ratio of at least about 1.3:1 and more preferably at least about 1.8:1.

[0035] Fig. 1 D illustrates the use of the device 110 with a racket frame 126. The racket frame has holes defined in them for receiving main strings 128 and interwoven cross strings 130. The racket may also include one or more grommets 132 for isolating the strings from any sharp edges or sources of abrasion from the frame materials. It is seen also from Fig. 1 D how the device substantially surrounds a tie-off string 134 (within the interior of the frame), such that a tie-off can be accomplished by passing a string 136 through a hole that is shared with the tie-off string, and forming a knot 138 around the projection 1 14. The tie-off string accordingly is free of direct contact with a knot that can abrade it, shear it or both. The present invention is suitable for and contemplates forming a knot selected from a double half hitch knot, a Parnell knot, or other suitable knot.

[0036] The embodiment of Figs. 2A-2D illustrates another illustrative tie-off device 210 of the invention, pursuant to which a base portion 212 supports a surface projection 214 that extends axially away from the base portion and terminates at a free end 216. In the embodiment shown, the surface projection 214 is depicted as being located stacked on top of the base portion 212. In Fig. 2C the surface projection is axially aligned with the base portion, to create a structure that resembles a bushing having a concave outer wall surface 218. Though shown as having an outer diameter (or other outer peripheral surface dimension) on the base that is substantially equal to that of the free end, it is not necessary in every instance. For example, it is possible that the free end will have a smaller outer dimension than the base. Preferably the device of this embodiment will include a neck region 220 having a diameter (or other outer peripheral surface dimension) that is smaller than the diameter (or other outer peripheral surface dimension) at the free end, or elsewhere along the length of the projection. It can be seen that the structures thus have defined in the base portion 212 a through hole 222 or other suitable opening. As may be employed for the structure defining the through holes in the embodiments of the present invention, an inner wall surface 224 may include an arcuate profile, such as a continuously arcuate (e.g., convex) profile. Wall surface 218 optionally may have an aperture defined therein through which a string may be passed. [0037] The device of this embodiment is depicted as having a generally circular bottom on the base portion 212. Other geometries are possible, and may include arcuate shapes (e.g., a generally elliptical shape) that are free of any corners, geometric shapes (e.g., polygonal) having one or more corners, or a combination. Though other geometries are possible, preferably the largest dimension of the base portion (e.g., the length (L) of the base portion) is larger than the height (H) of the device at its tallest portion. For example, preferably the largest dimension of the base portion (e.g., the length (L) of the base portion) is larger than the height (H) of the device at its tallest portion by a ratio of at least about 1.1 :1 and more preferably at least about 1.4:1.

[0038] Fig. 2D illustrates the use of the device 210 with a racket frame 226. The racket frame has holes defined in them for receiving main strings 228 and interwoven cross strings 230. The racket may also include one or more grommets 232 for isolating the strings from any sharp edges or sources of abrasion from the frame materials. It is seen also from Fig. 2D how the device substantially surrounds a tie-off string 234, such that a tie-off can be accomplished by passing a string 236 through a hole that is shared with the tie-off string, and forming a knot 238 around the projection 214. The tie-off string accordingly is free of direct contact with a knot that can abrade it, shear it or both. As with the other embodiments herein the present invention is suitable for and contemplates forming a knot selected from a double half hitch knot, a Parnell knot, or other suitable knot.

[0039] The embodiment of Figs. 3A-3D illustrates yet another illustrative tie-off device 310 of the invention, pursuant to which a base portion 312 supports a surface projection 314 that extends away from the base portion and terminates integrally with an upper portion 316 of the device. In the embodiment shown, the surface projection 314 is depicted as being located toward an end 318 of the device 310, and projecting inwardly toward the center of the device, where it integrally reconnects with the device (e.g., at a top portion of the device). It is also possible that the surface projection is located at a generally central portion of the device, instead of or in addition to the ends 318. As seen, more than one surface projection 314 may be used (e.g., a projection 314 on opposite sides of the device). The surface projection may have a substantially constant peripheral cross-section along the projection. As shown, the surface projection may have a peripheral cross section that varies along its length. Specifically, there is shown a neck region 320 having a diameter (or other outer peripheral surface dimension) that may be smaller than the diameter (or other outer peripheral surface dimension) at the free end, or elsewhere along the length of the projection. In the base portion 312 of the device, there is defined a through hole 322 or other suitable opening. Though shown in Fig. 3C as possibly having an inwardly sloping inner wall surface 324, such a feature may be omitted. [0040] As with the other embodiments herein, the device of this embodiment is depicted as having a generally elliptical bottom on the base portion 312. Other geometries are possible, and may include arcuate shapes (e.g., a generally circular geometry as in Figs. 2A-2D), that are free of any corners, geometric shapes (e.g., polygonal) having one or more corners, or a combination. Though other geometries are possible, preferably the largest dimension of the base portion (e.g., the length (L) of the base portion) is larger than the height (H) of the device at its tallest portion. For example, preferably the largest dimension of the base portion (e.g., the length (L) of the base portion) is larger than the height (H) of the device at its tallest portion by a ratio of at least about 1.3:1 and more preferably at least about 1.8:1. [0041] Fig. 3D illustrates the use of the device 310 with a racket frame 326. The racket frame has holes defined in them for receiving main strings 328 and interwoven cross strings 330. The racket may also include one or more grommets 332 for isolating the strings from any sharp edges or sources of abrasion from the frame materials. It is seen also from Fig. 3D how the device substantially surrounds a tie-off string 334, such that a tie-off can be accomplished by passing a string 336 through a hole that is shared with the tie-off string, and forming a knot 338 around the projection 314. The tie-off string accordingly is free of direct contact with a knot that can abrade it, shear it or both. The present invention is suitable for and contemplates forming a knot selected from a double half hitch knot, a Parnell knot, or other suitable knot.

[0042] The embodiment of Figs. 4A-4D illustrates yet another illustrative tie-off device 410 of the invention, pursuant to which a base portion 412 supports a surface projection 414 that extends away from the base portion and terminates integrally with an upper portion 416 of the device. In the embodiment shown, the surface projection 414 is depicted as being located toward an end 418 of the device 410, and projecting inwardly toward the center of the device, where it integrally reconnects with the device (e.g., at a top portion of the device), it is also possible that the surface projection is located at a generally central portion of the device, instead of or in addition to the ends 418. As seen, though more than one surface projection 414 is used (e.g., a projection 414 on opposite sides of the device as in the embodiment of Figs. 3A-3D), preferably only a single projection is used, or a projection configuration is used that is asymmetrical along the length of the device. The surface projection may have a substantially constant peripheral cross-section along the projection. As shown, the surface projection may have a peripheral cross section that varies along its length. Specifically, there may be shown a neck region 420 having a diameter (or other outer peripheral surface dimension) that is smaller than the diameter (or other outer peripheral surface dimension) at the free end, or elsewhere along the length of the projection. In the base portion 412 of the device, there may be defined a through hole 422 or other suitable opening. The through hole 422 is depicted as optionally having an inclined wall structure 424 defining it. However, such a feature may be omitted (e.g., in favor of a wall structure as in the embodiments of Figs. 1 A-3D). [0043] As with the other embodiments herein, the device of this embodiment is depicted as having a generally elliptical bottom on the base portion 412. Other geometries are possible, and may include arcuate shapes (e.g., a generally circular geometry as in Figs. 2A-2D), that are free of any corners, geometric shapes (e.g., polygonal) having one or more corners, or a combination. Though other geometries are possible, preferably the largest dimension of the base portion (e.g., the length (L) of the base portion) is larger than the height (H) of the device at its tallest portion. For example, preferably the largest dimension of the base portion (e.g., the length (L) of the base portion) is larger than the height (H) of the device at its tallest portion by a ratio of at least about 1.3:1 and more preferably at least about 1.8:1. [0044] Fig. 4D illustrates the use of the device 410 with a racket frame 426. The racket frame has holes defined in them for receiving main strings 428 and interwoven cross strings 430. The racket may also include one or more grommets 432 for isolating the strings from any sharp edges or sources of abrasion from the frame materials. It is seen also from Fig. 4D how the device substantially surrounds a tie-off string 434, such that a tie-off can be accomplished by passing a string 436 through a hole that is shared with the tie-off string, and forming a knot 438 around the projection 414. The tie-off string accordingly is free of a knot that can abrade it, shear it or both. The present invention is suitable for and contemplates forming a knot selected from a double half hitch knot, a Parnell knot, or other suitable knot. [0045] As will be appreciated from the above, one or more features on one embodiment may be include as part of another embodiment. For example, as discussed, geometries may vary, projections may vary in location, the inner through hole or other passage may be sloping, inclined, convex, undercut or otherwise. The geometry of the devices may be substantially symmetrical about the throughhole, or asyemtrical. A projection with a free end (as in Figs. 1A-1 D) may be combined with the structure of any of the embodiments of Figs. 2A-4D. The constricted annular central portion geometry of the embodiment of Figs. 2A-2D may be included around the periphery of any of the embodiments of Figs. 1A-1 D or 3A-4D. The throughhole profile of any of the embodiments, as depicted in Figs. 1 C, 2C, 3C or 4C may be interchanged in the respective embodiments. One feature of the specific embodiments herein (e.g., Figs. 2A-4D) is that the external surfaces that project away from a racket when deployed are generally continuously arcuate, and thus optionally are free of any corners or edges. It is also possible to configure the tie-off devices herein to include a nest that receives the knot. For example, a molded geometry might be included that is complimentary to the expected shape that a knot will make. Forming the knot can thus be guided by shape of the nest. [0046] The bottom surface of the devices may be configured to be attached for permanent or temporary retention onto a frame of a racket. There may be a sealing gasket, an adhesive or other intermediate layer or structure that lies between the bottom surface and the racket frame, and helps to resist rotation about the at least one string grommet.

[0047] It is also possible that the attachment is a direct attachment by which the bottom surface is in direct opposing contact with the racket frame. It is also possible that a racket frame is configured so that it incorporates the geometry of the devices of the present invention. For example, the present invention also contemplates rackets that integrally include the device of the present invention as part of the originally formed (e.g., molded) racket frame. The devices herein may also comprise part of a racket head guard, that protects the outer periphery of a frame from abrasion.

[0048] It is also not necessary that the openings be through holes that have defining wall structure that entirely surrounds it. There may be a partial cut-out in the device, or the device may even be slit from top to bottom, and from its side to its throughhole, so that if necessary the device can be placed around a string that already has been pulled from the racket, after the pulling has occurred. This way it may be possible to avoid having to undo the string job and start over again. [0049] The size of the tie off devices of the present invention may vary as needed. Preferably the device will be sized so that it fits over one or more string holes (and any grommet) but it includes no portion that extends beyond the leading or trailing edge of a racket frame. By way of example, without limitation the height (H), the width (W) and length (L) of the device may generally be within about 40% of each other (e.g., one or both of the H and W are about 8 to 10 mm; the L may be about that amount or it may be higher, e.g., about 10 to about 13 mm). The smallest inner diameter of any throughhole (ID) is about 5 mm or less (e.g., about 3 mm or less). The tie-off projection may have a generally constant sectional profile along its length. It may include one or more tapered portions, such as is seen in Figs. 3B and 4B. Smaller or larger dimensions than the above are also possible, with the relative proportions as set forth. Measurements of H, W and L are illustrated in Figs. 1 B and 1C, with like measurements to be employed for the other embodiments as well. [0050] The devices herein can be employed for stringing any of a variety of rackets using any suitable racket string (e.g., a solid core filament with one or more outer filament wraps, a multifilament structure with or without one or more outer filament wraps, a string of natural material (e.g., natural gut), a string of synthetic material or any combination). The racket string typically has a cross-sectional diameter from about 14 to about 20 gauge (e.g., 15 to about 18 gauge) or about 0.8 to about 1.7 mm, or more preferably about 1.0 to about 1.5 mm. [0051] Methods herein may include steps of inserting main strings through holes in a racket frame, pulling tension main strings, weaving cross strings through tensioned main strings and tying off a knot with a main string, cross string or both by passing it through the tie-off device and knotting it around a projection of the tie-off device, so that the knot is free of any direct contact with a tie-off string. [0052] The explanations and illustrations presented herein are intended to acquaint others skilled in the art with the invention, its principles, and its practical application. Those skilled in the art may adapt and apply the invention in its numerous forms, as may be best suited to the requirements of a particular use. Accordingly, the specific embodiments of the present invention as set forth are not intended as being exhaustive or limiting of the invention. The scope of the invention should, therefore, be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incorporated by reference for all purposes. Other combinations are also possible as will be gleaned from the following claims, which are also hereby incorporated by reference into this written description.

Claims

CLAIMS What is claimed is:

1. A tie-off device for a string of a sporting racket having peripherally located string grommets through which racket string is pulled, comprising; a) a base portion that contacts a frame of the sporting racket proximate at least one string grommet; b) at least one offset surface projection that extends away from the base portion and around which a knot is made using the string, so that the projection anchors the knot to resist movement of the string through the at least one string grommet, and the string is thereby tied-off to a structure other than itself.

2. The tie-off device of claim 1 , wherein the base portion is configured to substantially surround the at least one string grommet.

3. The tie-off device of claim 1 or 2, wherein the base portion includes a centrally located opening that is generally axially aligned with the at least one string grommet toward the interior of the frame.

4. The tie-off device of any of claims 1 through 3, wherein the base portion is wider than it is tall.

5. The tie-off device of any of claims 1 through 4, wherein the base portion is wider toward its bottom than toward its top.

6. The tie-off device of any of claims 1 through 5, wherein the at least one projection is a post having a free end.

7. The tie-off device of any of claims 1 through 6, wherein the at least one projection is connected at both of its ends to the base portion.

8. The tie-off device of any of claims 1 through 7, wherein the device includes a plurality of projections that extend from the base portion.

9. The tie-off device of any of claims 1 through 8, wherein the base portion is configured for resisting rotation about the at least one string grommet.

10. The tie-off device of any of claims 1 through 9, wherein the base portion includes an adhesive for bonding the base portion to the frame.

11. A sporting racket including the tie-off device of any of claims 1 through 10.

12. A method of stringing a sporting racket, comprising the step of tying off the racket string on the projection of the tie-off device of any of claims 1 through 10.