Title:
Racket and method of stringing the racket
Kind Code:
A1


Abstract:
According to one embodiment of the invention, a method for stringing a racket comprises inserting an end of a first string through a first grommet located along a frame of the racket, and re-inserting the end of the string through a second grommet. The second grommet is non-adjacent to the first grommet.



Inventors:
Riesser, William (Lawrenceville, NJ, US)
Application Number:
11/236008
Publication Date:
12/28/2006
Filing Date:
09/27/2005
Primary Class:
International Classes:
A63B49/14
View Patent Images:
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Primary Examiner:
CHIU, RALEIGH W
Attorney, Agent or Firm:
WOMBLE BOND DICKINSON (US) LLP (ATLANTA, GA, US)
Claims:
What is claimed is:

1. A method for stringing a racket, comprising: inserting an end of a first string through a first grommet located along a frame of the racket; and re-inserting the end of the string through a second grommet, the second grommet being non-adjacent to the first grommet.

2. The method of claim 1, wherein a third grommet is interposed between the first grommet and the second grommet located on a first edge of the racket.

3. The method of claim 2, wherein inserting a second string through the third grommet, the second string operating as a string segment in parallel with a string segment formed by the first string inserted through the first grommet.

4. The method of claim 2 further comprising: inserting an end of a second string through a fourth grommet located along a second edge of the frame of the racket, the second edge of the frame being opposite the first edge of the frame; inserting the end of the second string through the third grommet; and re-inserting the end of the second string through a fifth grommet adjacent to the second grommet and non-adjacent to the third grommet.

5. The method of claim 4 further comprising: alternating an orientation of the first string from operating as a main string to operating as a cross string being transverse to the main string by inserting the first string into a sixth grommet in a first direction and reinserting the first string into a seventh grommet in a second direction substantially perpendicular to the first direction.

6. The method of claim 5, wherein the sixth grommet is adjacent to the seventh grommet.

7. The method of claim 5 further comprising: alternating an orientation of the second string from operating as a main string to operating as a cross string being transverse to the main string by inserting the second string into an eighth grommet in the first direction and reinserting the second string into a ninth grommet in the second direction substantially perpendicular to the first direction; and continuing a pattern by feeding the first string and the second string into non-adjacent grommets along the frame of the racket.

8. The method of claim 7, wherein the racket includes at least fourteen main strings and at least eighteen cross strings.

9. A racket comprising: a frame including an substantially elliptical head and including a plurality of grommets situated along an edge of the frame; and a string bed formed by a plurality of strings inserted through the plurality of grommets, the string bed comprises (i) a first string operating as a first string segment of the string bed, and after insertion through a first grommet and re-inserted into a second grommet non-adjacent to the first grommet, operating as a second string segment of the string bed, and (ii) a second string operating as a third string segment of the string bed interposed between the first string segment and the second string segment, and after insertion through a third grommet positioned between the first grommet and the second grommet and re-insertion through a fourth grommet adjacent to the second grommet, operating as a fourth string segment of the string bed.

10. The racket of claim 9, wherein the first string segment, the second string segment, the third string segment and the fourth string segment are oriented in parallel across the head of the frame.

11. The racket of claim 9, wherein an end of the first string is external to the frame after insertion through the first grommet.

12. The racket of claim 9, wherein the string bed commences with a loop where, prior to the first string being inserted through the first grommet, a first end of the string is patterned in a loop fed through a first pair of grommets located at a corner of the head, a second pair of grommets located at a next corner of the head and a third pair of grommets located at a third corner of the head, through each of which corners the direction of the string segment so formed reorients by approximately a right angle.

13. A racket comprising: a frame including a plurality of grommets situated along an edge of the frame; and a string bed formed by a plurality of strings fed through the plurality of grommets in a selected pattern, the selected pattern of the string bed comprises a first string inserted through a first grommet of the plurality of grommets and re-inserted through a second grommet being non-adjacent to the first grommet, and a second string inserted through a third grommet positioned between the first grommet and the second grommet and, the second string re-inserted through a fourth grommet adjacent to the second grommet and non-adjacent to the third grommet.

14. The racket of claim 13, wherein the first string and the second string operate as main strings being substantially in parallel.

15. The racket of claim 13, wherein the first string operates as at least a first string segment and a second string segment after re-insertion into the string bed through the second grommet.

16. The racket of claim 15, wherein the second string operates as at least a third string segment and a fourth string segment after re-insertion into the string bed through the fourth grommet.

17. The racket of claim 16, wherein the string bed includes at least fourteen string segments, including the first string segment, the second string segment, the third string segment and the fourth string segment in parallel, and at least eighteen string segments transverse to the at least fourteen string segments.

Description:

This application claims the benefit of priority on U.S. Provisional Application No. 60/692,782 filed Jun. 22, 2005.

FIELD Embodiments of the invention relate to a racket and a method of stringing a racket.

GENERAL BACKGROUND

In general, all types of “rackets”, such as tennis racquets, racketball rackets and squash rackets for example, have two major components: (1) a racket frame and (2) strings placed across a face of the racket frame. For the past forty years, a great amount of effort and technology has been devoted toward improving racket frames. However, relatively little effort has been devoted to the positioning of the strings and the method of stringing the face of the racket to form the “bed” which actually contacts the ball.

Currently, rackets are designed and strung with an inadequate stringing pattern, which normally is formed using a conventional stringing technique where strings are wrapped sequentially from one grommet position to the next. Although the conventional stringing technique (similar stringing patterns have been predominantly used since the game of “lawn” tennis was first invented in the nineteenth century) is used by virtually every current racket manufacturer, this technique is not the most effective possible stringing design. The reason is that, upon striking a string bed formed by the conventional stringing technique, a ball will for example evenly impinge upon two strings, which will fight each other at their “shared” grommet feed holes. As a result, these two strings can only stretch by pulling on their outer neighboring strings. The effect is that conventionally strung rackets impart momentum change to the ball in a dramatically uneven fashion, and in varying directions, throughout the string bed.

As an illustrative example, shown in FIGS. 1 and 2, when string 7 contacts a ball 1, it is almost instantaneously met with resistance from both of its adjacent strings 6 and 8. As a result, string 7 is prevented from stretching more than allowed by adjacent strings 6 and 8 because these strings further tug on their neighboring strings (e.g., strings 5 and 9 of FIG. 2). This means that strings 6-8 form a generally flat platform for striking ball 1, and the situation is further exacerbated when strings 5 and 9 come into play during the maximum compression/expansion of ball 1 as shown in FIG. 2.

In FIG. 2, strings 5 and 9 can tug on their neighbors to allow perhaps more expansion than any of strings 6, 7 or 8 could attain. This means that strings 5 and 9 will have less tension than the three central strings 6-8, and thus, ball I will experience a condition where it is being pushed most in its center and least at the edges. As a result, there will be minimal or no “cupping effect,” meaning that ball 1 will be forced (or “shot”) outward from the center, away from whatever direction strings 5-9 happen to be applying the greatest resistant force against ball 1. Rather than being guided by the player, ball 1 proceeds along the path of least resistance, in other words traveling where it feels the least resistance, which is a random event coming most likely from the proximity of the ball's strike on the strings of the racket to the closest part(s) of the frame.

This behavior of conventionally strung rackets has caused many advanced players to typically string their rackets at as high a tension as they can, so that the racket's string bed behaves more nearly like a solid bat than like a bed of strings. For instance, one famous tennis player is reputed to have had his rackets strung at around 90 pounds tension, at which there would be relatively little rebound effect. That higher tension causes a slight increase in uniformity of response off the string bed, but at the price of lost power and frequently broken strings.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments of the invention may best be understood by referring to the following description and accompanying drawings that are used to illustrate these embodiments.

FIG. 1 illustrates resistance levels of strings of a racket strung according to a conventional stringing technique where the strings are wrapped sequentially from one grommet position to the next.

FIG. 2 illustrates resistance levels of the strings of FIG. 1 during maximum compression/expansion of an incoming ball.

FIG. 3 illustrates resistance levels of strings of a racket strung according to the general embodiment of the invention.

FIG. 4 illustrates resistance levels of additional neighboring strings of a racket strung according to the general embodiment of the invention.

FIG. 5 is a general descriptive diagram of the new stringing technique as applied to strings in one direction.

FIG. 6 is a continuation of FIG. 5 showing how, in general, strings might wrap from one principal direction to another and further proceed when using the new stringing technique.

FIG. 7 is an exemplary embodiment of the new stringing technique as applied to a specific, currently available, racket frame geometry.

FIG. 8 is an exemplary embodiment of the new stringing technique of FIG. 7 inclusive of additional stringing features.

FIG. 9 is another exemplary embodiment of the new stringing technique as applied to a currently available racket frame geometry, and inclusive of additional features.

FIG. 10 is an exemplary embodiment of the new stringing technique of FIGS. 7-9 for a different racket frame geometry, and inclusive of additional stringing features.

FIG. 11 is an exemplary embodiment of the new stringing technique including features like those of FIG. 10, but for a racket frame geometry that includes one additional string segment.

FIG. 12 is an exemplary embodiment of the new stringing technique of FIGS. 7-11 for a different racket frame geometry, and inclusive of four additional stringing features.

FIG. 13 is an exemplary embodiment of the new stringing technique for a currently existing racket frame of an unusual configuration called a “tweener”.

FIG. 14 is an exemplary embodiment of the new stringing technique for another currently existing racket frame geometry.

FIG. 15 is an exemplary embodiment of the new stringing technique for a proposed racket geometry, and contains an ancillary two-dimensional diagram of the cooperating strings notion which is central to this patent.

FIG. 16 is a different exemplary embodiment of the new stringing technique for the proposed racket geometry of FIG. 15.

FIG. 17 is a detailed view of a racket accommodating the stringing geometry as diagrammed in FIG. 16.

FIG. 18 is an exemplary embodiment of a device inserted within string a bed at string intersection points to further enhance the effects of the invention.

DETAILED DESCRIPTION

Herein, certain embodiments of the invention relate to a racket and a method of stringing the racket that provides better shot control due to more consistent behavior between main strings and cross strings associated with the string pattern. The newly developed stringing practices involve alternating strings being fed in both directions in the creation of the string bed.

More specifically, rather than continuously routing a single string end from one grommet to an immediately adjacent grommet, in either a main string or cross string orientation, a pair of string ends proceed out of adjacent grommets and are fed by “leapfrogging” each other. If, for example, a first main string features one end of a string protruding from a first grommet at the top of the frame (or head) and a second main string has the other end of that continuous string protruding out the top of the frame, then first main string is fed into a third grommet to operate as a third main string segment, where the second grommet is interposed between the first and third grommets. Similarly, the end from the second main string is fed into a fourth grommet to operate as a fourth main string segment. The third grommet is interposed between the second and fourth grommets. The same general stringing pattern continues.

I. General Definition of Terms

In the following descriptions, certain terminology is used to describe features of embodiments of the invention.

The term “string bed” generally refers to the entirety of strings that lie inside the frame of the racket, and concerns how those strings interact. According to one embodiment, a “string” refers to a segment of a continuous string routed through multiple grommets (described below) to form the string bed. Multiple string segments, perhaps from the same continuous string, are used to create the string bed.

In the most common types of stringing geometries, intersecting strings include main strings and cross strings. According to one embodiment of the invention, “main strings” are longitudinally oriented through the face of a racket frame and are generally of a greater length than the cross strings. “Cross strings” are oriented transverse to the main strings and intersect at least one main string at approximately a right angle. Of course, the orientation of main and cross strings may be respectfully vertical and horizontal, with the main strings being the longer of the two transverse string segments. As an unusual choice, diagonal stringing geometries may be utilized where string segments all lie at an angle to the longitudinal axis of the racket head. Such an unusual stringing geometry may be adapted to utilize the inventive aspects described herein.

“Grommets” generally refer to reinforced apertures positioned around the frame of the racket where strings enter and exit the face in a pattern to create the racket's string bed.

“Grommet feeds” concern how (geometrically) the string wraps around the racket frame in feeding from one grommet to the next.

“Neighboring strings” generally refer to string segments of the string bed that are connected by a continuous physical line of string through a couple of grommets and a grommet feed about the racket frame.

“Adjacent strings” generally refer to the strings oriented in the same direction that are closest to a given string segment within the string bed arrangement. While neighboring strings are almost always equivalent to adjacent strings for conventional stringing techniques, for these embodiments of the invention, the stringing technique involves neighboring strings having intervening adjacent strings since the strings alternate.

“Cupping” generally refers to a condition where, in response to a ball contacting an area of the string bed of the racket, the centermost string or pair of strings (relative to the ball) experiences a greater amount of expansion (stretch) than the nearest adjacent strings. Similarly, strings further removed from the center of the contact area will have even less expansion, and in some cases, may be considered generally taut. Such behavior is presently only observed when using the “cooperative alternating strings” techniques described in this patent.

II. Production of Cupping

As shown in FIGS. 3 and 4, a racket strung in accordance with one of a variety of embodiments of the invention provides greater control than conventionally strung rackets. One reason is that strings 105-109 are in physical contact with a ball 100 for a longer period of time than with other stringing methods. Another reason is due to the ball cupping functionality, which can be seen from the figures and description set forth below.

As a starting point, suppose ball 100 impacts the strings in one direction (sequentially numbered) at string 107. The forces applied by ball 100 would likely be most concentrated on string 107 during the total period of contact. It should be emphasized that this is an event normally having a short duration such as a hundredth of a second or less, despite the softness of ball 100 and the ability of strings 105-109 to stretch (e.g., generally both ball 100 and strings 105-109 have high elasticity). While these diagrams focus on the strings in one direction, the same type of analysis can be conducted, largely independently, for the strings which are perpendicular to strings 105-109. It is contemplated that the strings in both directions, (namely, the main and cross strings) should exhibit similar responses in order to provide a consistent behavior.

More specifically, string 107 will be able to stretch along its length (e.g., expand lengthwise) and, by pulling on its neighboring strings, namely strings 105 and 109, string 107 may extend lengthwise through grommets of the racket frame. Thus, string 107 will be substantially stretched in a lengthwise direction, within those scant moments of contact. Once ball 100 starts to flatten at the time of maximum force, strings 108 and 106 will be stretched as well, perhaps only a little more than one-half of lengthwise extension of string 107. As a result, in general, string 107 will be fully stretched, and strings 106 and 108 will be stretching slightly greater than one-half (e.g., approximately 60 percent) as much as string 107 as generally indicated in FIG. 4.

In addition, strings 105 and 109 will be largely stretched by the pull from string 107, so they will only be able to slightly stretch, largely through their other neighbors (e.g., strings 103 and 111, not pictured). This means that a “cupping” effect is achieved among the five predominant strings, with the centermost (e.g., string 107) having the largest stretch, with the two most adjacent strings (e.g., strings 106 and 108) stretching somewhat less, while the two outermost strings (e.g., strings 105 and 109) will be largely taut to complete the cupping. Because of the typical spacing between string segments of approximately one-half inch, and the size of a tennis, squash or racket ball of around two inches, there are four or five strings in each direction that will contact the ball when striking it with typical forces involved in playing these sports.

III. General Embodiment

FIG. 5 illustrates initial stages of a general embodiment of the invention, shown for several of the main strings. A first section of string represented by solid lines enters a string bed 150 (indicated as a dashed-line bounded region in this and many subsequent figures) on the right side of a frame 200 through grommet 201, and thus, becomes main string 202. A second section of string represented by zig-zag lines enters string bed 150 just below main string 202 through grommet 204, becoming main string 205.

As further shown, these main strings 202 and 205 exit string bed 150 on the left side of frame 200 though respective grommets 203 and 206. Thereafter, main string 202 wraps down about frame 200 to re-enter string bed 150 through grommet 207, and now operates as main string 208. Grommets 203 and 207 are non-adjacent grommets. Similarly, main string 205 wraps down to re-enter string bed 150 through a non-adjacent grommet 210 to operate as main string 211.

Upon reaching the right side of frame 200, main strings 208 and 211 are fed through grommets 209 and 212 positioned within frame 200. Thereafter, main string 208 re-enters through grommet 213 to become main string 214 until its exit at grommet 215. Main string 211 re-enters at grommet 216 thereby becoming main string 217, before exiting via grommet 218. This “idealized” stringing configuration for a typical frame geometry would have sixteen main strings all alternating from top to bottom as depicted in FIG. 5, namely a pair of string ends proceed out of adjacent grommets and are each fed by “leapfrogging” neighboring grommets.

An idealized implementation for the cross strings is the same as for the main strings, and is described below. In order to avoid string sections from being constrained at either end more than absolutely necessary, stringing patterns are configured with string sections wrapped at appropriate positions from main strings to cross strings, or vice versa. A later continuation of the “idealized” stringing pattern of FIG. 5, which accomplishes the wrapping from main strings to cross strings, is shown in FIG. 6.

In FIG. 6, there are main string groups which are being completed when approaching the bottom, starting with main strings 221 and 224 that enter string bed 150 from the left through frame 200. Main string 221 is positioned generally longitudinally across the head of frame 200 and is inserted into grommet 220 and exits through an opposite grommet 222. Thereafter, the continuation of that string portion is inserted into a non-adjacent grommet 226 so then to operate as main string 227, which exits frame 200 through grommet 228. The same continuous string now feeds down frame 200 to enter via non-adjacent grommet 232, whereupon it operates as main string 233, and departs string bed 150 via grommet 234. Similarly, the alternate string portion begins as main string 224 upon entering string bed 150 through grommet 223 and exiting through grommet 225. That portion re-enters at non-adjacent grommet 229 to operate as main string 230 and exits at grommet 231, and concludes its longitudinal stringing pattern as main string 236, which enters string bed 150 via grommet 235 and exits string bed 150 at grommet 237.

In the lower right corner, main string 233 exits through grommet 234 and then operates as a cross (transverse) string 239 after re-entering string bed 150 through grommet 238. Main string 236 exits through grommet 237 and then operates as cross string 242 upon re-entering string bed 150 through grommet 241. Transverse, cross strings 239 and 242 exit through grommets 240 and 243, and then re-enter string bed 150 through respective grommets 244 and 247 as cross strings 245 and 248, respectively. Thereafter, string segments 245 and 248 exit string bed 150 through grommets 246 and 249, re-enter string bed 150 through non-adjacent grommets 250 and 253 to operate as cross strings 251 and 254, respectively. These cross strings 251 and 254 exit through respective grommets 252 and 255. As virtually every tennis racket in use today has at least 18 cross strings, the idea given in this general example would be similarly repeated for a significant number of additional string segments.

As illustrated, in accordance with the above-described stringing technique, cross string 245 crosses a second-neighboring string 233 back in the lower right corner of spring bed 150 near frame 200, and similarly cross string 248 crosses its second neighboring string 236. Neither of these “competing string segments” represents a significant problem because there is an intervening string and the competing segment intersection is so close to frame 200 that these strings would only be “outer ball” contact points where one wants less string movement freedom anyway.

Upon stringing a racket in a complete pattern such as the above-described “idealized” patterns of FIGS. 5 and 6, such a racket would create virtually identical behavior everywhere on the string bed 150 of the racket.

IV. General Description of Illustrative Embodiments

Herein, certain embodiments of the invention relate to a racket, and a method of stringing the racket, that provides better shot control due to more consistent behavior between main strings and cross strings associated with the string pattern. The newly developed stringing practices involve alternating strings being fed in both directions during creation of the string bed.

Since two string segments will not stretch at a point where they are tied together (referred to herein as “tieoff”), another inventive aspect is to maximize string cooperation in stretching by avoiding tieoffs to the fullest extent possible, especially for string segments within the string bed that proceed well away from the peripheries of the racket (defined by the head of the frame). Such tieoffs are also best configured with a run about the frame so that there is still some string that can stretch. For this reason, a single continuous string is normally used, rather than a pair of strings which would have four tieoffs (two ends of two) rather than two tieoffs. However, this invention is not limited to single continuous string implementations.

While it is, in a practical sense, extremely difficult to have a single continuous string always feeding in such an alternating fashion, it is typically possible to accomplish this ordering amongst the majority of the strings. Where there are exceptions, the exceptions should be confined mostly to strings that are around the periphery of the racket rather than near its center, and it is considered most beneficial to preserve the ordering for cross strings in particular (since cross strings are shorter and thus more susceptible to both mutual and “frame” interference with their stretching).

Herein, certain details are set forth below in order to provide a thorough understanding of various embodiments of the invention, albeit the invention may be practiced through many embodiments other that those illustrated. Well-known components and operations are not set forth in detail in order to avoid unnecessarily obscuring this description.

Herein, the stringing patterns described in FIGS. 7-17 provide greater uniformity of response, coupled with a dramatic increase in controlling the movement of the ball due to both the longer ball-to-string-bed contact time, and the cupping/guidance effect. Players can use lower tensions for greater rebound of their shots, or higher tensions if they are powerful players with long strokes. However, a player highly accustomed to a certain playing tension associated with a particular racket frame may want to practice in the new stringing patterns by stringing his or her racket with a slightly (2-4 pounds) higher tension in order to lessen the enhanced “trampoline” effect caused by the alternating string patterns described below. Otherwise, greater power is derived from the same tension as was used before with the conventionally-strung racket.

Herein, the new stringing method is illustrated using varied exemplary rackets, commercially available and strung in accordance with the unique stringing techniques described above. These rackets will exhibit a significant improvement in performance, namely better power and far superior control of the movement of the ball when hit by the racket. The stringing patterns, considered as a whole, represent examples to retrofit many types of existing racket frames to take advantage of the dramatically improved control capabilities of this string ordering.

Specific stringing patterns have been developed for a variety of racket types. A most typical string pattern for the “standard” racket group is 16 main strings and 18 or 19 cross strings (although some rackets have more strings in one or both directions). Generally, there are two main strings in each corner that impinge within the cross strings along the frame (or two cross strings that impinge on the main strings is another equivalent way to think about it).

V. First Embodiment—FIG. 7

Referring now to FIG. 7, a first exemplary embodiment of a stringing technique conducted for a first type of racket geometry (e.g., WILSON® PROSTAFF® 6.0 and/or WILSON® TRIAD® 6.0 racket frames) is illustrated. As shown, cross strings 321-338 are numbered along the left side of a frame 300 while main strings 301-316 are numbered at the bottom of frame 300. Two string representations (solid and zigzag) have been used in the stringing diagrams to help clarify the different “halves” of the string, although the strings described below are segments of a continuous string between two tie-offs onto main strings 312 and 314.

In using this pattern, the rackets were strung with a concerted effort to make the racket utilize alternating strings to the extent possible. Most rackets of current design have six main string grommets in the throat, making a fully alternating pattern impossible for the main strings. But alternating strings are less important for the longer main strings than for the cross strings.

With this pattern, there are several strings that involve transitions between a cross string and a main string that intersect in string bed 350 at intersections shown as circles numbered 317-320. For example (lower left) cross string 323 wraps down frame 300 and feeds into main string 304, intersecting as is labeled with circle 320.

A ball that strikes in the area of that intersection 320 will have competition between those two strings as to which will be permitted to fully stretch, much like adjacent strings fight in conventional stringing patterns. In the upper left corner, there are three intersections 317-319, all fairly close to each other, and any ball striking the upper left of string bed 350 has a pretty good chance of striking competing strings.

The order of pulling strings inside racket frame 300 is illustrated by small italic numbers (see operations 1-45). The direction of string pulls is illustrated by arrows while phases of the stringing process are indicated with roman numerals (I-IV). It is contemplated that the string pattern can be performed in four (4) phases, which are completed as units, so that all strings within each phase are fed prior to doing any string tensioning. This reduces the effort in feeding strings through grommets that are largely blocked by other strings that have already been fully tensioned.

Herein, the total length of string is initially evenly divided at the juncture between the solid and zigzag portions under the center at the throat, as indicated by the reference label “Middle”, so that the lengths of string associated with strings 307 and 310 from the top are substantially the same. In each of the first three phases, the two string ends should be fed loosely through all their positions for that phase, prior to tightening any strings. Enough slack should be left at a phase's (two continuing) starting points to enable the tensioning mechanism to function freely.

A. Phase I of the First String Procedure (Center Mains)

Two main strings 307 and 309 are clamped in their centers as shown with the “START” rounded box. Main string 310 is pulled at the top and subsequently clamped to main string 309 (see operation 1), which is half tensioned along with all of strings 307 and 310. Main string 308 is then pulled through the throat (left free of the initial clamp) and clamped near the throat to string 307 (see operation 2). Thereafter, main string 306 is pulled at the top and clamped to main string 307 (see operation 3). Then, main string 309 is pulled at the throat and clamped to main string 310 near frame 300 (see operation 4). Main string 311 is then pulled and clamped near frame 300 (see operation 5). At this point, there are six (6) main strings tensioned and clamped, and the strings leave from the top of the racket. The two string ends should have a few more inches of length on main string 306 than on main string 311, because the strings represented by solid lines have a little farther to go from this point than the strings represented by zig-zag lines.

B. Phase II: (Right Side Main Strings; Initial Corners with Weaving)

Main string 306 is fed through grommets at the top of frame 300 to become main string 312, which is pulled and subsequently clamped to main string 311 (see operation 6). Main string 311 is fed through frame 300 as main string 313 and clamped to main string 312 behind the clamping of main string 312 to main string 311 (see operation 7). Main string 314 is tensioned (see operation 8), and thereafter, main string 313 is re-tensioned and clamped near the throat (see operation 9). Similarly, main string 315 is tensioned and clamped behind the clamp holding main string 314 to main string 313 (see operation 10). Main string 316 is tensioned (see operation 11), and thereafter, main string 315 is re-tensioned and clamped near the top (see operation 12).

Cross strings 322 and 338 are pulled and clamped using main string 306 to hold their clamps at the left of frame 300 near the throat and top, respectively (see operations 13 &14). Note that cross string 338 will go under main string 314 (upper right) if cross string 322 goes over main string 315 (lower right). Main string 301 is tensioned and initially clamped outside of the frame to hold its tension (see operation 15) until main string 302 is clamped to it (see operation 16). Once main strings 301 and 302 are clamped together at their bottoms, main string 301 is re-tensioned and its clamp is repositioned inside of the frame (see operation 17). Completing this phase involves tensioning and clamping cross strings 321 and 337 (see operations 18 &19).

C. Phase III: (Finish Corners, Left Side Main Strings)

Cross string 323 is tensioned and clamped to cross string 322 short of the positions of main strings 303 and 304 (see operation 20). Similarly, cross string 335 is clamped using main string 306 to hold the clamp out of the way of main string 303 (see operation 21), and thereafter, main string 303 is tensioned and clamped to main string 302 above cross string 323 (see operation 22). Then, main string 304 is tensioned and clamped to main string 303 (see operation 23), which is then re-tensioned and clamped to main string 304 near the throat (see operation 24). Main string 305 is pulled and clamped outside frame 300 (see operation 25), and thereafter, main string 304 is re-tensioned and clamped to main string 305 above the position of cross string 336 (see operation 26). Cross string 336 is tensioned and clamped to cross string 335 using the clamp which had been outside the frame on main string 305, now being held by the main strings 304/305 clamp (see operation 27).

D. Phase IV (Central Cross Strings)

Cross string 334 is pulled and clamped to cross string 335 (see operation 28). Cross string 333 is pulled and clamped to cross string 334 (see operation 29). In feeding and tensioning cross strings 332, 330, 328 and 326, these strings are tensioned twice, namely before and after tensioning cross strings 331, 329, 327 and 325. This respectively allows the strings to be clamped near the frame.

    • 1. Cross string 332 tensioned and clamped to cross string 333 behind cross string 333's clamp (see operation 30)
    • 2. Cross string 331 tensioned and clamped on left to cross string 332 (see operation 31)
    • 3. Cross string 332 re-tensioned and clamped on right to cross string 331 (see operation 32)
    • 4. Cross string 330 tensioned and clamped to cross string 331 behind cross string 331's clamp (see operation 33)
    • 5. Cross string 329 tensioned and clamped on right to cross string 330 (see operation 34)
    • 6. Cross string 330 re-tensioned and clamped on left to cross string 329 (see operation 35)
    • 7. Cross string 328 tensioned and clamped to cross string 329 behind cross string 329's clamp (see operation 36)
    • 8. Cross string 327 tensioned and clamped on left to cross string 328 (see operation 37)
    • 9. Cross string 328 re-tensioned and clamped on right to cross string 327 (see operation 38)
    • 10. Cross string 326 tensioned and clamped to cross string 327 behind cross string 327's clamp (see operation 39)
    • 11. Cross string 325 tensioned and clamped on right to cross string 326 (see operation 40)
    • 12. Cross string 326 re-tensioned and clamped on left to 325 (see operation 41).

Tension cross string 324 and clamp (see operations 42, 44), and then tie-off cross strings 325 and 324 (see operations 43, 45) to main strings 312 and 314.

VI. Second Embodiment—FIG. 8

Referring to FIG. 8, a second exemplary embodiment of a racket stringing technique is illustrated. As previously labeled, and similarly further applicable to FIGS. 9-16 as well, cross strings 421-438 are numbered on the left side and main strings 401-416 are numbered below. This pattern reduces the exposure of the more central strings to crossing of neighbors (retaining an interference between main string 403 and cross string 436 at location 417), and has a fairly full alternating pattern between cross strings 422 and 437 and main strings 403 through 414, excepting the six (6) central strings of string bed 450. String bed 450 commences with a polygon-shaped (e.g., rectangular) loop that goes from (starting from upper right) cross string 438, down main string 402, across on cross string 421, then back up to main string 416.

Such stringing may begin with a “loop” about the outer strings according to the pattern describe above, but it is contemplated that the initial loop is more optimally implemented using the outermost main strings and the second-from-edge cross strings. What the initial loop does is to create a good initial point for all subsequent strings to clamp to, for fuller tensions when stringing.

A difficulty may be encountered with this pattern when proceeding through the central main strings, especially string 408 if using “floating” clamps. A stringing machine might have clamps that are secured to the machine's racket turntable (the “fixed clamp” feature of more expensive machines) or it might have clamps that hang from the strings without any support aside from the strings' holds to frame grommets (the floating clamps that are used with less expensive machines including most “home” models). In that latter case, when first routing main string 408 in an upward direction toward the top of frame 400, main string 408 has no opposite-direction strings to which to clamp. A solution is to clamp that main string 408 (see operation 12) outside frame 400 where the clamp remains while tensioning an adjacent main string 407 (clamped to main string 408 and routed in an opposite direction from string 409). In this case, prior to initially clamping main string 408 outside frame 400, it is advisable to feed main strings 407 and 409. This possible issue is noted via operation 12* being outside the frame. If using a more professional stringing machine, string 408 is clamped inside the top of frame 400 in operation 12 and operation 16 can thus be skipped.

VII. Third Embodiment—FIG. 9

Referring to FIG. 9, a third exemplary embodiment of a racket stringing technique similar to FIG. 7 or 8 with an additional stringing feature is illustrated. An initial loop is positioned between the outermost main strings and the second-from-outermost cross strings. Keeping strings that intersect substantially near frame 500 in this pattern, are desirable to keep the “heart” of the string bed 550 optimally pliant.

In a subsequent secondary implementation, small holes were drilled in frame 500 to allow tie-offs to main string 501 (from “final cross strings 521 and 523). On both of the existing frames, the grommets for main string 501 are too small to allow other strings to pass through them to tie-off there, and creating the additional drilled holes allows such a tie-off.

VIII. Fourth Embodiment—FIG. 10

FIG. 10 illustrates a fourth exemplary embodiment of the stringing technique for a racket having eighteen (18) main strings and nineteen (19) cross strings. An example of such a racket includes, but is not limited or restricted to the WILSON® 110 Staff 6.5 SI racket, which is a mid-plus racket with the main strings toward the center of string bed 640 noticeably closer together than those main strings of string bed 640 nearer the racket frame 600. In addition, frame 600 has eight (8) main string grommets in the throat area (not specifically shown), so a fuller alternating pattern could be employed for the main strings.

The center of the string is positioned at the lower right corner of frame 600, where main string 618 feeds down and left to cross string 621. To start, main strings 601 and 603 are clamped together near their centers, and main string 601 is routed downward. Thereafter, cross string 621 is tensioned, followed in counterclockwise order by main string 618, cross string 637 and thereafter, main string 602 to complete the initial loop (with main string 602 clamped to main string 601). The remaining main strings (603-617) are tensioned and clamped in order and in a similar manner to that which has been previously detailed relative to FIGS. 7-9.

Main string 616 is fed through to cross string 638, which is tensioned and clamped. Main string 617 is fed to cross string 636, which is tensioned and clamped. Cross string 638 is fed down to cross string 635, and then the alternating strings are fed and tensioned in (decreasing label numerical) order until cross strings 623 and 622, again in like manner to the earlier descriptions pursuant to FIGS. 7 and 8. Cross string 622 is tied off to an available string, and cross string 623 feeds down to cross string 620 after which that end is tied off

There is an additional marking that does not appear on the previous stringing patterns, which is a rounded rectangle 639 called the “rectangle of perfection”. The rectangle of perfection is the region in a nearly optimally strung racket, which should provide precisely uniform response and optimal control from the “cupping”, for a ball which impinges within that rectangle 639. Every string is implemented with precisely configured adjacent stringing, according to the theory, and does not have intersecting strings nor does it have any tie-offs or other interference with freedom to all its neighboring strings. Although this racket frame 600 was designed as a conventional stringing-pattern racket, it has a strong capability to take advantage of such a modern pattern.

This particular pattern has a general rectangle of perfection 639, although the diagrammed rectangle could not actually be achieved because grommet geometry made it necessary to tie-off the ends to cross string 623 and main string 604, reducing those segments' abilities to stretch and compromising the perfection rectangle. The rectangle's effectiveness is also reduced because the string “density” is higher in the center of string bed 640. That is, due to the positions of grommet holes, adjacent main string segments 606-613 are substantially closer together in spacing than are the other main string segments.

IX. Fifth Embodiment—FIG. 11

A very similar pattern to that in FIG. 10 could be employed, for example, with either of two 95 square inch MidPlus™ rackets that have eighteen (18) main strings and twenty (20) cross strings with two impinging strings in the corners and eight (8) throat main string grommets (including, but not restricted to, HEADS® Liquidmetal Radical and YONEX® RDX500HD). Referring to FIG. 11, another string segment (641) is positioned between cross strings 622 and 621 (relabeled as 621a) and is “fed” from cross string 623. Cross string 622 feeds down to cross string 620a, and the weaving of bottom cross strings 620a and 621a are reversed relative to FIG. 10. Since the strings represented by a zigzag illustrative feature have eighteen (18) total segments in FIG. 10 to nineteen (19) strings illustrated as solid in FIG. 10, this leaves the “Middle” of the string pattern still in the lower right with the same number (19) of segments for each half in the case of FIG. 11. As is indicated on FIG. 11, the rectangle of perfection (639a) is one cross string larger than it was in FIG. 10, but tieoffs may again be an issue.

X. Sixth Embodiment—FIG. 12

FIG. 12 illustrates a sixth exemplary embodiment of a stringing technique for a racket, such as egg-shaped racket frame 650 (a narrower curve near the throat than at the top of head) found in a HEADS® Ti Laser racket. With this racket, there is more “skipping” of main grommet positions at the throat end of the racket than at the top end of frame 650, since three cross strings impinge on main strings at the bottom, versus only one cross string impinging at the top. The pattern that was settled upon in utilizing the inventive aspects of this patent for this geometry was an initial, upside down, “L” shape of strings (main strings 651 and 653, and cross strings 687 and 689) rather than an initial loop. It should be emphasized that an “L”-shaped pattern is not regarded as an advantage compared to the preferred initial loop, but it was deemed necessary for optimal use of the other ideas being used with frame 650.

It is noted that frame 650 includes two cross strings passing between the outermost and adjacent main strings, namely cross strings 672 and 673. For this embodiment, main strings 651-666, and cross strings 671-689 form a string bed 690.

Another feature of this string pattern is that there is an arrow showing (upper left corner) the direction of pull of main string 651, but there is actually no operation number associated with that arrow. A second operation (operation 2) is actually cross string 687 being pulled back toward the left, prior to main string 652 being pulled downward in operation 3 to complete a “cycle” of the initial “L”.

Another feature associated with the racket frame is the use of tubing made of a low-friction material (e.g., TEFLON®) in place of grommet holes. TEFLON® is well known to be a very low-friction material—it was initially used in consumer products for non-stick cookware but has more recently found numerous additional applications. By drilling out the grommet holes with a drill just larger than the outer diameter of the tubing (approximately 5/64″), the tubing can be inserted as a “non-stick” grommet hole, and it is positioned so that the string will wrap around the tubing both in entering and exiting string bed 690. With this replacement of the grommet holes around frame 650, the strings will slip quite freely in the manner described relative to FIGS. 3 and 4. Such use of low-friction tubing in retrofitting a racket frame is an alternative to the design of a frame custom for the alternating, cooperating strings idea that is one feature of the invention.

Within this stringing pattern for frame 650, it is considered worthwhile to re-route the grommet feed for the two main strings that are fifth from the outermost (655 and 662) so that those string segments have neighboring segments within the throat region of the frame (e.g., neighboring strings 657 and 660 respectively). The grommet holes are drilled almost straight from string bed 690 to operate as an exit point of string 655, and from the grommet feed exit point to become string segment 662, into the throat region. Like all the other grommet holes, the low-friction tubing was inserted into those newly-created grommet feeds.

Because all the grommet holes had been filled with low-friction tubing, and there is generally a limited desire to drill additional holes in a racket frame for tieoffs, it may be worthwhile to design a new tieoff mechanism for this frame and pattern. Instead of the two ends of a long continuous string tying onto string segments, it was determined that the two ends (coming out from string segment 671 on the left and string segment 672 on the right side of frame 650) would be tied directly to frame 650. This is referred to herein as a “Frame tieoff,” which is another feature of this embodiment. A string is fed between grommets 653 and 671 in the lower left of frame 650, and between grommets 665 and 672 in the lower right side, so that the string does not have to “cross” any strings on the way to its tieoff. A triple knot is created on the outside of frame 650, and that tieoff will not interfere with the “slipping” of any string segments in the string bed.

The use of the tubing also has a tendency to cause the strings to offset slightly because the tubing extends outside the frame enough to contact other grommet-fed strings. This means that the strings that are outside frame 650 will not rub directly against each other as they tend to do when strung without such offsets. The tubing serves somewhat in the role of spacing separators. Each tube is cut to a length of approximately an inch, somewhat more or less depending on the thickness of the frame at each grommet position.

Note that because of the initial “L” of this pattern, the rectangle of perfection 670 is shifted to the right and down from its more typical centralized position within string bed 690. An expert player could adapt to this rectangle by always maintaining the position of that rectangle 670 for either slightly higher or slightly lower shots. It is not presently known for certain whether rectangle of perfection 670 is more important for shots that are very low or those which are caught high, but the most difficult shots to control properly (for very good players) are shots which are met extremely low so it may be most prudent to play with this racket's rectangle down low. That means that a right-handed player would grip the racket with the palm down into FIG. 11 for the forehand shot (and a left-hander would grip this racket as a “palm up”).

XI. Seventh Embodiment—FIG. 13

Referring to FIG. 13, a seventh exemplary embodiment is given of this stringing technique for another racket for which a stringing pattern has been diagrammed for illustrative purposes. This racket is called a “tweener” (marketed by X-45 Corporation of Miami, Fla.), where a conventionally configured head is set at approximately 45 degrees from the handle, meaning that it still has main strings 701-714 and cross strings, 721-738, but all the strings 701-738 are diagonally set relative to the throat (740) and handle (not shown, proceeding further to lower right). Although this racket was designed as a conventional stringing-pattern racket, it has a strong capability to take advantage of such a modern pattern.

In FIG. 13, the cross strings are numbered at the right side in order to avoid considerable interference between those numbers and the around-the-frame feeds from main string 701 down to cross string 722, and from main string 704 to cross string 723, as well as the tieoff to main string 701 from cross string 736.

The middle of the entire continuous string is positioned at the lower left where main string 702 will feed right to cross string 721. It is noted that this racket frame head (700) utilizes only fourteen (14) main strings 701-714, making it more accommodating for using “around the frame” feeds without needing substantial additional string length. It also has the ability to tie-off to main strings 701 and 714 in diagonal wraparounds.

XII. Eighth Embodiment—FIG. 14

Many Babolat rackets (16 main strings×19 cross strings) have a head frame shape such that there is only a single cross string grommet that is between the main string grommets in each corner. That means that it can be strung commencing with a single loop, and a suggested pattern is performed as follows according to FIG. 14: The continuous string is fed between cross string 789 (at the top) and main string 766 (on the right) such that the length of string is the same in either direction. Proceeding clockwise, that string is fed in the initial loop to cross 771 and main string 751, then turns down into main string 753. Main strings 751 and 753 are clamped together in their middles, and main string 751 is tensioned downward then released. In sequence each of the other string segments in the initial loop is tensioned then released: cross string 771, main string 766, and cross string 789. Cross string 789 is fed into main string 752, which is then tensioned and clamped to main string 751. Main string 753 is fully tensioned and clamped to main string 752.

The sequence of strings from one tie to the other is as follows: Tie—Crosses 772, 774, 776, 778, 780, 782, 784, 786, 788, Mains 764, 762, 760, 757, 759, 756, 754, 752, Cross 789—Middle—Main 766, Cross 771, Mains 751 (Start), 753, 755, 758, 761, 763, 765, Crosses 787, 785, 783, 781, 779, 777, 775, 773—Tie. It is not contemplated that a listing of the sequence of the strings, as just stated, will be easily useful in actually stringing a racket because the string segments are being fed at both “free” ends in the above list. Also, the more rectangular shape of the head of the frame which this stringing geometry requires seems to result in a somewhat weaker frame, and Babolat and other manufacturers seem to more recently be manufacturing frames in the more elliptical geometries that are most common today.

XIII. Ninth Embodiment—FIG. 15

Referring to FIG. 15, a ninth exemplary embodiment of a stringing technique inclusive of additional stringing features is shown. This pattern is slightly easier to string than the pattern set forth in the following FIG. 16 (and FIG. 17), because there is less wrapping of strings around a frame 800. Note the size of a rectangle of perfection 820, which is around half the total string bed 870.

Currently available commercial rackets often only have six grommets in the throat (center bottom but not shown) so the centermost main strings need to go in triples as, for example, FIGS. 7-9 and 14 above. In many cases, it is possible to drill a grommet down from the feed positions of (for example from FIG. 15) main string segments 805 and 812, subsequently insert into such newly created holes a low-friction tubing such as is sometimes used to effect minor repairs to grommets, and then feed the string as indicated on diagrams like FIGS. 15 and 16. FIGS. 15, 16 and 17 are for a racket 800 or 900 which has grommet positions that are optimal for the new stringing order, with eight (8) main string grommets in the throat allowing two full paired loops of strings in the centermost main strings (see main strings 805-812 of FIG. 15 or main strings 905-912 of FIG. 16).

Note that the tie-offs are onto main strings 801 and 816, and include a wraparound of the upper frame prior to those tie-offs. This pattern does involve two significant competing crossing strings (main string 803 with cross string 824 noted as circle 819, and main string 804 with cross spring 823 noted as circle 818) but their location just outside the rectangle of perfection 820 is a good compromise. This pattern also “begins” with two outer loops, and when commencing the second loop one needs to clamp main string 813 (in operation 6) outside frame 800 when using floating clamps (a similar discussion is found in the second embodiment relative to FIG. 8).

XIV. Revisiting the Ball “Cupping” with Two String Directions

Entirely within rectangle of perfection 820 for FIG. 15, there are additional markings associated with a ball strike 840 near the center of string bed 870. A plurality of arrowheads 841-866 are in four sections relative to a ball 840 coming into contact with string bed 870: arrows 841-846 illustrated above ball 840; arrows 847-852 to its right; arrows 861-866 to its left; and arrows 853-860 illustrated below ball 840. Each arrow 841-866 shows the direction of the portion of a string segment between ball 840 and frame 800 that is pulled by the strike of ball 840. There are a total of twenty-six (26) actions upon string segment portions (numbered arrows 841-866) that are caused by the strike of this ball in the indicated position, involving a total of fifteen (15) string segments (8 main string segments 805-812, and 7 cross string segments 829-835). Involving that large a portion of string bed 870 is a good thing, and is a perspective from which to view the advantages of the instant invention.

When ball 840 strikes main strings 808 and 809, it pulls inward from frame 800 those segments on both sides, as is indicated by arrows 843 and 844 above and arrows 856 and 857 below. In turn, these portions cause the pulling indicated by arrows 841, 846, 854 and 859. Because of the particular geometry of the grommet feeds, these pulling motions have slightly different effects on string behavior vis-à-vis ball 840, but in essence main strings 807 and 810 will be more taut for the segments above the ball than those below in this case. The cupping effect in this diagrammed case, for the main strings, will occur because of the upper segments, since those two “outer” strings below (relative to ball 840) will not encounter any resistance to “fight” the pulls indicated by arrows 855 and 858. At the bottom portion, arrows 853, 854, 859 and 860 indicate that main string segments 812, 811, 806 and 805 respectively will all contribute stretching capability for the four main strings that actually contact the ball. While the discussion of FIGS. 3 and 4 concerned a single principal contact string segment for a given string orientation, this helps to show that very similar advantages of cupping occur when there are two shared main contact string segments. For this invention, a cupping motion occurs in both string directions and regardless of the “central” point of contact of the ball relative to the matrix of string segments.

Looking at the cross strings relative to ball 840, it is contemplated that there is the single main contact string segment, cross string 832. Arrows 850 and 864 show the pull inward of that string on either side, and they result in outward arrows for the neighboring strings in each direction, arrows 847 and 862. For the right “side” of this ball 840, string segment 834 is made taut and for the left “side”, string 830 is made taut to perform the outermost cupping motion described earlier in reference to FIG. 4. Again looking at the string segment portions on the right side of ball 840, segments 831 and 833 are competing since they are neighboring strings, indicated by paired arrows 851 and 852, and 848 and 849, respectively. On the left side, string segments 831 and 833 have other string segments as neighbors, so they are able to do the majority of their stretching by pulling on their left-side neighbors as indicated by arrows 863 and 861 (for segment 831) and arrows 865 and 866 (for segment 833).

From the above-described paragraphs, we see that the cupping motion as previously discussed is actually a combination of behaviors on all four “sides” of ball 840, and involves an appreciable fraction of the string segments in the overall string bed 870.

XV. Tenth Embodiment—FIGS. 16, 17 &18

Referring to FIG. 16, a tenth exemplary embodiment is directed to the stringing technique, conducted concurrently with additional stringing features. The initial loop includes main strings 901 and 916, and cross strings 922 and 938. Note that cross string 922 feeds outside frame 900 to main string 915, and that main string 903 again wraps around frame 900 to cross string 939. This reduces the effect of having the crossing strings be neighboring, so that the only interference appears between cross string 937 and main string 902, which is hardly a problem.

While the fashion in which rackets are strung probably has by far the greatest effect on the behavior of string bed 950, there are frame and grommet design considerations which can further enhance the advantages of the modern alternating stringing order as discussed herein. First, while strings 901-916 and 921-939 can move through conventional grommets, those grommets form some resistance to the movement, which would be alleviated by reconfiguring those grommets. Apertures in these grommets should be shaped to allow a more free movement, and the proposal is to have elliptical connections of a string's exit from the bed, and re-entry position two apertures removed (when the string is continuing in the opposite direction). There are actually two elliptical segments employed for each grommet feed in the model (FIG. 17), which run parallel to the string where it enters the string bed from the frame, and meet at a point where both ellipses have the same slope that is equal to the local slope of the frame. As was previously mentioned, the strings should also form a matrix that is as uniform in density throughout the bed as possible, to create the most uniform response.

As described below, grommet connections are designed to create the maximum freedom between neighboring strings. Each pair of strings that connect frame 900 are separated by a string that is itself connected to another neighbor at that same side of frame 900, and in general, if the two strings that are being considered are first woven below their closest crossing string, those other two strings are woven above that same string. It is therefore logical that the two strings which should have their grommets above the grommets of the other two. Various racket manufacturers have tried rackets that are in a similar configuration, but never have they seemed to understand the critical nature of alternating pairs of strings cooperating in guiding and bouncing the ball by their stretching and moving through those grommets as has been discussed here.

At the top of the frame, there are three quadruplets of main strings if the racket is designed with eight grommets inside the throat and the stringing order as suggested is employed. Those quadruplets are main strings 903-906, main strings 907-910, and main strings 911-914. Selecting an example, if the two paired main strings 903 and 905 are going under cross string 939 (the uppermost one), then the pair inclusive of main strings 904 and 906 should go over cross string 939 to weave properly. Since the strings in string bed 950 intersect at small angles, this means that the grommets at the top of frame 900 for main strings 903 and 905 should be somewhat above those for main strings 904 and 906. By slightly separating the intersecting ellipse-based grommet guides around frame 900, strings 901-939 will not rub against each other, such as would happen with a conventionally designed racket. The freedom of movement through the grommets and around the frame will thereby be enhanced somewhat.

Now there is a list to “study” of which grommets are raised (toward the viewer of FIG. 17 seen face-on, or FIG. 16) or lowered (values given in millimeters “mm” where “raised” is represented by a positive number and “lowered” is represented by a negative number) for coordinating main strings and cross strings:

Lower left corner, proceeding counterclockwise: main 901: −1 mm/cross 922: 0, main 902:0, main 904: −1, cross 921: −1, main 903:+1, main 905/907: +1, main 906/908: −1, main 909/911: +1, main 910/912: −1, main 913:+1/main 915: 0, main 914: 0/main 916: +1, cross 921: 0, cross 922:+½, cross 923: −1/cross 925: +1, cross 924: −1/cross 926: −1, cross 927/929: +1, cross 928/930: −1, cross 931/933: +1, cross 932/934: −1, cross 935: +1/cross 937: −1, main 916: +1/cross 938: 0, main 915: 0, cross 939: 0, main 914: 0/main 912: −1, main 913/911: +1, main 910/908: −1, main 909/907: +1, main 906/904: −1, main 905: +1/main 903: 0, cross 939: 0, main 902:0/cross 937: +1, cross 938: 0/main 901: −1, cross 936: 0/ cross 934: +1, cross 935/933: −1, cross 932/930: +1, cross 931/929: −1, cross 928/926: +1, cross 927/925: −1, cross 924/921: 0, cross 923: +1.

On the left side view, the front of frame 900 (facing viewer in main view) is to the right; on the right side view the front of frame 900 is on the left.

Close examination of FIG. 17 will reveal that there are fine lines emanating outward in frame 900 from each string. These are the straight sides of slots that reach to the outside of frame 900, which will make frame 900 easier to manufacture, and provide more accessibility in stringing the racket as well. Each grommet “section” is the depth of thick string (e.g., 15 gauge) and has the gray-indicated straight side and elliptical side going in toward the hole facing string bed 950.

In order to most effectively employ the alternating stringing order, there are the following features as mentioned previously in this document. These features are directed to particular embodiments of the invention. However, it is contemplated that the invention may be practiced with any combination of these features satisfied:

    • 1. The string bed 950 should be as uniform in density as possible.
    • 2. Starting with the initial “loop” places potentially inconsistent string tension in its least-affecting position- some of the outermost strings.
    • 3. Strings should not wrap directly from main strings to (crossing) cross strings or vice-versa.
    • 4. Tie-off positions should be somewhere around the outermost strings-suggestions are main strings 1 and (maximum) typically 16. A frame tieoff as is discussed for FIG. 12 is another possibility to contemplate.
    • 5. The alternating order should commence fully as far “out” in the string bed as possible, preferably directly inside the initial loop.
    • 6. Grommet guides should be configured in a smooth manner to allow the maximum freedom possible—the proposed ellipse-based design is at least a fairly convenient form of that idea. (Grommets can be, and often are, made as plastic frame inserts).
    • 7. The alternating connection loops (grommet guides) on the frame should be slightly (and alternatingly) offset, by perhaps slightly more than the maximum thickness of string that would be employed.
    • 8. The stringing pattern should encourage long runs prior to tie-offs. A string that wraps a foot around the frame will provide that much freedom of movement for its connecting string bed string segment. This design would be best employed with strings that have a length of approximately 42 feet (a few such commercial strings are sold, but there need to be more).

If frame 900 is made of a graphite compound, it is likely that will provide sufficient friction-reducing capability to allow “fairly” free movement of the strings through the grommets and guides. Even as a racket is strung, there is some abrasion on grommet areas, which becomes more pronounced with use, so friction is reduced in “normal” use. Where the strings cross each other in string bed 950, one would like to provide less friction both to reduce string wear from tribological effects, and to allow fuller string motion. For that purpose a set of slipdisks 975, shown positioned at the 292 string intersections in string bed 950 of FIG. 17, might be implemented, which are made of a light metal, perhaps aluminum, or some type of “slippery” thermosetting material.

The geometry of these slipdisks 975 is shown herein as FIG. 18, which shows a combination of concave (top) and convex (bottom) geometry, where main string 916 goes over slipdisk 975, and cross string 927 is woven under and holds slipdisk 975 from below. Similar intersection inserts have been previously proposed and designed to reduce or prevent string movement and are placed at a few string intersection points, but these are instead intended to allow for smoother string motion and are to be placed within all string intersections, to prevent strings (e.g., strings 916 &927) from rubbing directly against each other.

While the embodiments of the invention have been described in terms of several embodiments, those of ordinary skill in the art will recognize that the embodiments of the invention are not limited to those described, but can be practiced with modification and alteration within the spirit and scope of the appended claims. The description is thus to be regarded as illustrative instead of limiting.