Patent Application
20240390741
This nonprovisional application claims priority under 35 U.S.C. § 119 (a) to German Patent Application No. 10 2023 114 018.3, which was filed in Germany on May 26, 2023, and which is herein incorporated by reference.
The present invention relates generally to a stringing arrangement for a ball sports racket, and in particular to a ball sports racket having a stringing of this type.
Strung conventional ball sports rackets (hereinafter also: rackets), such as a tennis, squash or badminton racket, comprise a frame which merges into a handle and the enclosed area of which is fitted with strings (strung). Here, the playing characteristics of the ball sports racket are influenced, inter alia, by the material, the arrangement of the strings, the length of the strings and the string-fitting strength (the tension of the strings, more precisely the tensioning force).
In the case of the known rackets having longitudinal and transverse strings, the string-fitting has a uniform string-fitting strength for the two hitting or playing sides of the racket, i.e. the playing or hitting characteristics are identical for the two sides or hitting areas. The same applies to rackets, the longitudinal and transverse strings of which have different string-fitting strengths. In the case of table tennis rackets, it is possible to realize different playing characteristics for the two racket sides by means of different covers. This is not possible in the case of strung or string-fitted rackets since the stringing arrangement stretched in the frame has identical playing characteristics on both playing sides.
Generally speaking, there is a need for a strung or string-fitted racket that has different playing or hitting characteristics on each of the two hitting sides (racket sides).
According to a first aspect, the present disclosure relates to a stringing arrangement for a ball sports racket which has a frame surrounding a string array and in the case of which the strings of a racket string-fitting are supported and guided by string guides formed on the frame, the string guides being formed asymmetrically in such a way that a free length of the string respectively guided on the string guide is, perpendicular to the striking direction and to a string-fitting plane of the racket, greater on one side of the string-fitting plane than on the other side of the string-fitting plane so that a tension and/or elasticity criterion of the stringing arrangement is different for each of the two sides of the string-fitting plane.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes, combinations, and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:
General explanations of the invention are initially provided, followed by a detailed description of an example with reference to the figures.
The string-fitting strength (tensioning force) and the string length of the stringing of a racket influence the tension or elasticity criterion of the string-fitting decisively and thus also the playing characteristics thereof. In this case, a distinction is generally made between softer and harder string-fittings. The string lengths can also vary depending on the size of the racket head.
A softer string-fitting of a racket offers a higher ball acceleration. Rackets with a larger head render possible enlarged so-called “sweet spots”, i.e. an increased area in the center of the string array where the game ball is played with maximum rebound force. Rackets of this type offer greater playing comfort, in particular for less experienced players, because less vibration occurs when the ball is hit outside the center of the string array.
A softer string-fitting requires better ball control by the player (accurate hitting point, precise racket control and control of striking force and striking direction).
A harder string-fitting of the racket facilitates ball control but makes ball acceleration more difficult. A medium string-fitting strength can offer a suitable compromise.
Depending on the stroke type (e.g. forehand, backhand, topspin, slice), different tension and/or elasticity criteria in one and the same racket can be helpful to be able to carry out one stroke with one tension and/or elasticity criterion and another stroke with another tension and/or elasticity criterion in optimized fashion.
Furthermore, it can also be helpful for advanced or professional players to make use of the different tension and/or elasticity criteria of a racket in a stroke-specific and/or game-specific manner.
Moreover, a ball sports racket having a stringing arrangement according to the present disclosure provides opportunities for different variations of play by the player in the game. For example, the string-fitting side that generates the higher striking force or the better topspin, i.e. a rotating game ball, can be used for a serve.
A further advantage of a ball sports racket having a stringing arrangement according to the present disclosure arises from the ability to counteract changing outside temperatures.
A ball sports racket having a stringing arrangement according to the present disclosure can also render possible a more energy-saving and joint-friendly game.
Thus, an object of the invention is to provide an improved stringing system as well as an improved ball sports racket.
The present invention now offers the possibility of realizing different tension and/or elasticity criteria on a single racket for each of the two playing areas or playing sides.
For this purpose, a stringing arrangement is provided for a ball sports racket which has a frame surrounding a string array and in which the strings of a racket string-fitting are supported and guided by string guides formed on the frame, the string guides being formed asymmetrically in such a way that a free length of the string respectively guided at the string guide is, perpendicular to the striking direction and to a string-fitting plane of the racket, greater on one side of the string-fitting plane than on the other side of the string-fitting plane so that a tension and/or elasticity criterion of the stringing arrangement is different for each of the two sides of the string-fitting plane.
In this context, the term stringing arrangement may refer to the manner, design and arrangement of the playing strings on and in connection with the racket or the racket frame or head.
A ball sports racket generally refers to a string-fitted racket having a string array surrounded by a frame, such as a tennis racket, squash racket, badminton racket, shuttlecock racket. The present disclosure is not limited to these types of rackets but also relates to other rackets string-fitted or strung in a similar manner and also to those provided with an elastic playing area or membrane.
Rackets of this type are usually strung crosswise longitudinally and transversely but also diagonally. The longitudinal direction here refers to the direction along the racket handle.
Racket frames are usually made from fiber-reinforced plastics profiles (hollow and/or solid) but also by using metal and/or wood materials. The desired frame shape and geometry is produced using standard molding methods.
The finished frame is fitted with strings, which are guided by string guides passing through the frame perpendicularly to the striking direction. The string guides may comprise bores, eyelets, sleeves and other elements of the racket frame, against which the strings rest in sections in each case or rest or are supported in sections in the deformed state while carrying out the stroke.
In the stringing arrangement according to the invention, the string guide is here asymmetrical so that a free length of the string guided by the string guide is greater on one string-fitting plane (hitting side) than on the other.
This has the effect that the one side of the string-fitting plane with the greater free length of the strings has a higher elasticity than the other side of the string-fitting plane, resulting in a different tension and/or elasticity criterion on both sides of the racket.
There are designs in which the string guides are designed in the form of openings as string channels passing through the racket frame. They pass through the frame in the string-fitting plane-usually longitudinally and transversely—from the inside to the outside so that the channels have an asymmetrical widening at their opening facing the string array.
The openings of the string guide here pass through the frame completely and are designed in such a way that they are different, i.e. asymmetrical, at the respective string-fitting planes in that e.g. an asymmetrical shape or form of the string guides is formed in or on the frame of the racket.
Thus, the free length of the respective string is different depending on the hitting side. On one side, the support length is greater and thus the free length of the string is smaller, while on the other side the support length is smaller and thus the free length is greater. This also changes the tension and/or elasticity criterion depending on the hitting side or impact side.
There are designs in which the openings (string channels) facing the string array are widened in the shape of a funnel in—i.e. parallel to—the striking direction.
In this case, the frame is provided with funnel-shaped or conical recesses on one side, which are drilled or shaped or made in the frame in a similar way. Here, the funnel axis runs at an angle to the string-fitting plane in each case.
At the string guides widening in this way, the string rests in a striking direction over the entire frame cross-section with a greater support length (shortened free length) while, in the other striking direction, it experiences a shortened support due to the widening (increased free length) and a greater mobility of the strings is possible in this direction, resulting overall in a different tension and/or elasticity criterion of the two string-fitting planes.
There are designs in which the opening facing the string array is widened in a slot-like manner parallel to the striking direction.
The string can move more freely in the opening direction of the slot than on the other side of the slot, where the string cannot be moved in the frame profile and abuts the entire support length. The slot can here be widened, for example, in a wedge-shaped straight or curved manner.
The opening facing the string array may widen in steps parallel to the striking direction.
The side of the string guide on the inner side of the frame can be provided with a narrow opening, and a larger opening of the string guide is created on the outer side of the frame, resulting in a stepped shape that allows an increased free length of the string on one side of the string-fitting plane.
The opening facing the string array can be curved in convex manner so that it is curved at the transition to the frame and fits tightly to the played string.
The widening side of the string guide can be funnel-shaped, slot-shaped, wedge-shaped, or step-shaped.
The asymmetrical string guide can be created by a frame profile that is thickened on one side of the string-fitting plane.
The frame profile of the racket is designed asymmetrically so that it has an increased cross-section on one side of the string-fitting plane in a direction perpendicular to the string-fitting plane compared to the opposite direction. As a result, the strings have a shorter free length on the side of the string-fitting plane with the increased frame profile cross-section on which they are supported, and the two hitting sides of the racket are thus different in terms of the tension and/or elasticity criteria.
In order to achieve this effect, it is also possible to provide a retrofittable inner frame profile which is fitted and fixed to one side of the racket frame as a curved bar or in a semicircular or semi-elliptical shape.
In this way, an inner frame can be provided which limits the elasticity of the string-fitting plane in one striking direction as described above.
Any one-sided reinforcement of a string-fitting side of a frame profile is here conceivable, and the above-described embodiment is not limited to the above mentioned forms of design.
Also, the asymmetrical string guide can be realized by a one-sided string stiffening, in particular in an area adjacent to the string guides.
A stiffening of the strings which is made in sections and/or on one side, if necessary, realizes tension and/or elasticity criteria that are modified on one side without using a special frame or special inserts as described below.
Different tension and/or elasticity criteria can be generated by either a different elasticity of the strings themselves in two directions or also the application of a special material, such as a spray, which stiffens the strings on one side or makes them more elastic.
The different elasticity of the strings on both playing sides of the ball sports racket can also be generated by a coating or treatment that stiffens the strings towards a striking or playing direction.
The asymmetrical string guide can be created by a plurality of sleeve-like support inserts that are fitted into the frame, the inserts being designed in such a way that the strings can move more freely on one side of the string-fitting plane compared to the other side of the string-fitting plane, resulting in a difference in a tension and/or elasticity criterion of the two playing sides.
For example, the inserts can have a semicircular, sleeve-like shape. According to a sleeve-like or bowl-shaped insert which is designed in this way and which is open on one side of the semicircular shape and is made of a stiff material on the other side, the free length of the strings and thus the elasticity of the string-fitting can be reduced in one striking direction.
The inserts can be formed from any material suitable for this purpose, such as metals, solid plastic materials, metal-plastics compounds, or also other sufficiently strong materials.
Furthermore, the inserts can be shaped in such a way that they have different stiffness on the respective string-fitting sides so that different string-fitting properties of the two string-fitting planes result from the different stiffness of the e.g. sleeve-like and/or eyelet-shaped inserts.
The above mentioned harder materials on one side of the insert in combination with a softer, e.g. elastomeric, plastic material on the other side of the insert are in consideration as a production material for such sleeves.
In a consistently semicircular example, the inserts can either be inserted into the string guides of an already string-fitted racket, or the racket is newly string-fitted with the inserts and the strings are passed through a circular design of the inserts.
The inserts can be fastened in the frame profile, for example, by screwing them in, gluing them in, clicking them in or inserting them.
In a further example, a stringing arrangement is provided, the plurality of inserts being contiguous, connected in one piece and rest against a frame side, for example, a tape or strip abutting the outside of the frame, and the thus contiguous inserts being inserted into the string channels from an outside of the frame. The tape or strip itself is either attached to the frame or fixed by means of string-fitting.
The racket can be provided with a marking indicating the respective racket side, or the orientation of the string-fitting plane.
The marking can here be formed as a haptically detectable attachment to the racket, for example in the form of an elevation, a depression or a relief.
For example, the handle can be provided with an elevation that can be felt with the thumb. This elevation can either be fixedly attached to the handle, or it can be designed, for example, as a sleeve provided with a suitable attachment that can be attached in the desired position on the handle or in the handle area of the racket.
Furthermore, the marker can be optically detectable. In this case, an optical marker can be applied to the handle.
In addition, the frame of the racket can also be designed in such a way that each of the two hitting sides has a distinctly different color scheme, for example, a light color on one hitting side and a dark color on the other.
According to the examples, the present disclosure shall be further illustrated with reference to the drawings.
Returning to
The string array 2 is defined by strings 3 string-fitted in the racket head 11 and comprising longitudinal and transverse strings 3a, 3b. In other designs, the strings 3 can be string-fitted diagonally, for example.
The strings 3 are guided through sleeve-like openings 4 formed in the frame 1 or racket head 11, the inner end 4a of which openings is widened and merges into the outer narrow end 4b via a funnel-shaped widening or one tapering steadily and/or stepwise (cf.
In this case, the funnel-shaped widening of the opening 4 is designed in such a way that it is widened in a direction perpendicular to that of the string-fitting plane or area 2a so that the string 3 can move freely in this direction in the inner end 4a of the opening 4, whereas it is restricted in movement in the opposite direction by the opening 4. At the outer end 4b, the string 3 is tightly guided through the opening and runs along the frame 1 into the adjacent opening 4.
Detail D marked in
The profile is narrower in the region of the string-fitting plane 2a, while it is wider in the region of the string-fitting plane 2b. This means that the string array 2 with the strings 3a, 3b can move more freely in a direction perpendicularly away from the string-fitting plane 2a, while in the opposite direction-perpendicularly away from that of the string-fitting plane 2b—it is supported by the annular frame profile, which is wider in this case, and its mobility is restricted. This inner ring can also be designed as a fixable insert (not shown), which can be coupled to a standard racket head and can be fixed thereto.
This results in different tension and/or elasticity criteria of the stringing arrangement for the playing or hitting surfaces in each case.
The illustrated schematic view of the tennis racket 100 shows a top view of the wider frame profile.
Alternatively or additionally, a color marking can also be provided or each of the racket sides can be marked in a different color. Furthermore, the following disclosure is characterized by these features:
(1) Stringing arrangement for a ball sports racket having a frame or racket head which surrounds a string array and in which the strings of a racket string-fitting are supported and guided by string guides formed on the frame, wherein the string guides are formed asymmetrically in such a way that a free length of the string respectively guided on the string guide is, perpendicular to the striking direction and to a string-fitting plane of the racket, greater on one side of the string-fitting plane than on the other side of the string-fitting plane so that a tension and/or elasticity criterion of the stringing arrangement is different for each of the two sides of the string-fitting plane.
(2) Stringing arrangement for a ball sports racket according to (1), wherein the string guides are designed in the form of openings as string channels which pass through the frame from the inside to the outside so that the channels have an asymmetrical widening at their opening facing the string array.
(3) Stringing arrangement according to (2), wherein the opening facing the string array is widened in the shape of a funnel parallel to the striking direction.
(4) Stringing arrangement according to (2), wherein the opening facing the string array is widened in a slot-like manner parallel to the striking direction.
(5) Stringing arrangement according to (2), wherein the opening facing the string array is widened in steps parallel to the striking direction.
(6) Stringing arrangement according to (2) to (5), wherein the opening facing the string array is curved in a convex manner in such a way that it is curved at the transition to the frame and fits tightly to the played string.
(7) Stringing arrangement according to (1), wherein the asymmetrical string guide is created by a frame profile which is thickened on one side of the string-fitting plane.
(8) Stringing arrangement according to (1), wherein the asymmetrical string guide is created by stiffening the strings on one side.
(9) Stringing arrangement according to (1), wherein the asymmetrical string guide is created by a plurality of sleeve-like inserts fitted into the frame, the inserts being designed in such a way that the strings can move more freely on one side of the string-fitting plane compared to the other side of the string-fitting plane.
(10) Stringing arrangement according to (9), wherein the plurality of inserts is contiguous, connected in one piece, and abuts a frame side.
(11) Handle for a ball sports racket having a stringing arrangement according to any one of (1) to (10), wherein the handle is provided with an optically and/or haptically detectable marking indicating the orientation of the string-fitting plane.
(12) Frame for a ball sports racket having a stringing arrangement according to any one of (1) to (11), wherein the frame indicates the orientation of the string-fitting plane by a different coloring of the two playing sides.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2023 114 018.3 | May 2023 | DE | national |
