EP2825268B1

EP2825268B1 - Sports racquet having an enlarged mesh size

Info

Publication number: EP2825268B1
Application number: EP13720066.3A
Authority: EP
Inventors: Mauro Pinaffo; Roberto GAZZARRA; Mauro Pezzato
Original assignee: Prince Sports LLC
Current assignee: Prince Sports LLC
Priority date: 2012-03-14
Filing date: 2013-03-12
Publication date: 2021-04-28
Anticipated expiration: 2033-03-12
Also published as: WO2013136266A1; ES2875009T3; HK1206214A1; EP2825268A1; ITTV20120038A1

Description

The present invention relates to a sports racquet, particularly for tennis, squash, badminton, racquetball, and similar sports.
As is known, a sports racquet comprises a handle and a head portion adapted to support a string bed comprising a plurality of longitudinal and transversal strings that intersect to form a plurality of meshes.
In traditional racquets, the head portion is typically strung using standardized designs involving the use of a pre-determined number of strings, depending on the type of racquet being strung.
Therefore, in racquets intended for less experience users, the string bed typically comprises 16 longitudinal strings and 18 or 19 transversal strings, while in racquets intended for more expert users or athletes, the string bed typically comprises 18 longitudinal strings and 19 or 20 transversal strings.
Since the maximum dimensions of the head portion of the racquet are defined by precise construction standards, the average area of the meshes on the string bed of a traditional racquet is generally around 150 mm².
Sports racquets exist that are characterized by a relatively high number of longitudinal and transversal strings, compared to traditional racquets.
In these cases, the average area of the meshes on the string bed may be smaller than the value given above.
For example, patent application GB2179863 describes a tennis racquet comprising a string bed with meshes with an average area of 81 mm² or smaller.
The main aim of the present invention is to provide a sports racquet, particularly for tennis, squash, badminton, racquetball, and other similar sports, that is endowed with improved characteristics.
In the context of this aim, one of the objects of the present invention is to provide a sports racquet that can offer relatively high performance compared to traditional racquets.
A further object of the present invention is to provide a sports racquet that is relatively easy to produce industrially, with competitive costs.
This aim and these objects, as well as other objects that will become more apparent from the following description, are achieved by a sports racquet according to claim 1, proposed below, and the relative dependent claims referring to preferred embodiments of the present invention. Further characteristics and advantages of the present invention will become more apparent
from the following detailed description of preferred embodiments of the sports racquet according to the invention, which is illustrated by no way of limitation in the accompanying drawings, in which:

figure 1 shows a schematic front view of the sports racquet, according to the invention, without strings and holes for the strings;
figure 2 shows a schematic cross-section view (cross section A-A) of the sports racquet shown in figure 1;
figure 3 shows a schematic front view of the sports racquet, according to the invention;
Figure 4 shows a perspective view of an exemplary sports racquet not being a part of the invention;
figure 5 shows a cross-section view of an embodiment of the sports racquet, according to the invention;
figures 6-8 show a perspective view, a cross-section view and a front view of a further embodiment of the sports racquet, according to the invention;
figures 9-10 show a perspective view and a cross-section front view of an embodiment of the sports racquet, according to the invention;
figure 11 shows a schematic view of the dynamics of a shot made with the sports racquet, according to the invention.

With reference to the aforementioned figures, the sports racquet 1, according to the invention, will be described with reference to a tennis racquet as shown in the aforementioned figures, without in any way limiting the scope of application of the invention, since the intended definition of a sports racquet includes racquets for tennis, squash, badminton, racquetball and similar sports.
The racquet 1 comprises a handle 2 and a head portion 3, the latter being adapted to support a string bed 4 (not shown in figures 1-2).
Preferably, the racquet 1 also comprises a throat section 7 adapted to join the head portion 3 to the handle 2.
The head portion 3 comprises an outer surface 310 and an inner surface 320, the latter being the surface that delimits the area where the string bed 4 lies.
Advantageously, the string bed 4 lies on a reference plane 40 that can be defined as the midplane of the volume of space occupied by the string bed itself (figure 2), which comprises the longitudinal axis Y and the transversal axis X of the head portion 3 of the racquet 1.
With reference to a front view of the racquet (figure 1), the longitudinal axis Y of the head portion 3 coincides with the main longitudinal axis of the racquet itself, lying on the reference plane 40.
The transversal axis X of the head portion 3 coincides with the axis lying on the reference plane 40 perpendicular to the longitudinal axis Y.
The transversal axis X intersects the longitudinal axis Y at a point C of the head portion 3, positioned at a distance L/2 from the ends of the head portion, L being the maximum longitudinal dimension of the head portion.
Advantageously, the longitudinal axis Y and transversal axis X form a system of four quadrants characterizing the head portion 3, in which quadrants I, II, III and IV are positioned at the top right, bottom right, bottom left and top left apexes of the head portion 3 respectively.
In the head portion 3, the string bed 4 comprises a plurality of longitudinal strings 41 and a plurality of transversal strings 42.
The longitudinal strings 41 are arranged in lines substantially parallel to the longitudinal axis Y, while the transversal strings 42 are arranged in lines substantially parallel to the transversal axis X.
The strings 41, 42 are arranged by appropriately stringing the head portion 3 using one or more strings made of synthetic or natural material.
The strings 41, 42 are arranged so that they mutually intersect and form a plurality of meshes 43.
Generally, the meshes 43 have a substantially rectangular shape. Near the inner surface 320 of the head portion 3, the meshes 43 may however assume a different shape, for example triangular or trapezoidal.
According to the invention, the strings 41, 42 are arranged so that the meshes 43 are enlarged with respect than those found on traditional racquets.
In particular, the strings 41, 42 are arranged so that the enlarged meshes 43 have an average area S_M of 200 mm² or more.
In the context of the present invention, the average area media S_M of the meshes 43 is given by the following equation: $S_{M} = \frac{\sum_{i = 1}^{N} (S_{i})}{N}$
where S_i is the area of the i-th mesh 43 of the string bed 4 and N is the total number of meshes 43 present on the string bed 4.
In the context of the present invention, the "area of a mesh" is defined as the area of a plane surface included between the strings that delimit the mesh and lying, for example, on the reference plane 40 (see figure 3).
Experimental tests in the field have shown how the use of a string bed 4 with enlarged meshes 43 (i.e. with an average area greater than 200 mm²) results in an increase in the energy that the racquet can exert on the ball, all other factors being equal.
In fact, upon coming into contact with the ball, the string bed 4 deforms more markedly than a traditional string bed.
This greater deformation reduces the amount of energy dissipated by the ball during the impact with the string bed.
In some preferred embodiments of the present invention, the strings 41, 42 are arranged so that the average area S_M of the meshes 43 of the string bed 4 on the head portion 3 is between 200 mm² and 250 mm², and preferably around 250 mm².
In this case, the racquet 1 is advantageously intended for expert players or athletes, who have greater skill in controlling shots.
Preferably, the strings 41, 42 are arranged so that the meshes 43 have an average area S_M of 600 mm² or less.
This makes it possible to further limit the intrinsic power of the racquet (i.e. the elastic energy that can be transmitted to the ball by the string bed 4), thereby enabling the player to have constant adequate control over his shots.
In some preferred embodiments of the present invention, the strings 41, 42 are arranged so that the average area S_M of the meshes 43 of the string bed 4 on the head portion 3 is between 300 mm² and 600 mm², preferably around 300 mm² or 400 mm².
These embodiments of the racquet 1 are advantageously intended for inexpert players or children, who are less able to control shots.
Figure 11 shows a schematic view of the dynamics 11 of a shot made by a player using the sports racquet 1.
The ball 100 arrives from an approach direction D_IN, touches the string bed at an impact point P_IMP and leaves the string bed 4 with an exit direction D_OUT.
Like all racquets, the racquet 1 is characterized by a certain approach angle β' of the ball 100 towards the string bed 4 and by a certain exit angle α' of the ball 100 away from the string bed 4.
The approach angle β' of the ball 100 is defined as the angle between the direction D_IN and a horizontal reference axis D_P, substantially parallel to the field of play.
The exit angle α' of the ball 100 is defined as the angle between the direction D_OUT and a horizontal reference axis Dp, substantially parallel to the field of play.
The exit angle α' of the ball 100 can be described by the equation α'= β' +/- α, where β' is the approach angle of the ball 100 and α is an angle that depends on the racquet's build characteristics.
In traditional racquets, α is typically less than 2°.
Experimental tests in the field have shown, surprisingly, how when using the racquet 1 with a string bed with enlarged meshes, all other build factors being equal, the exit angle of the ball 100 is given by the equation α'= β' +/- α, where β' is the approach angle of the ball 100 and α is a variable angle between 3° and 8°.
In the racquet 1, the strings 41, 42 are preferably arranged so that α is an angle of 5°.
These figures are further proof that using a string bed 4 with enlarged meshes 43 can result in an increase in the energy that the racquet can exert on the ball 100, all other factors being equal.
It is therefore possible to string the head portion 3 of the racquet 1 with relatively high string tensions.
This enables the player to have better control of shots, the intrinsic power of the racquet being the same.
The use of enlarged meshes 43 in the string bed 4 advantageously favors the use of strings with a relatively large diameter, so as to better withstand the greater stress generated by the increased deformation of the string bed.
Preferably, the diameter of the strings 41, 42 on the string bed 4 is 1.3 mm or greater.
The racquet 1 is characterized by a relatively small number of longitudinal and transversal strings 41, 42, compared to traditional solutions.
In the racquet 1, the number of longitudinal strings 41 is preferably between 8 and 16, while the number of transversal strings 42 is advantageously between 8 and 18.
As shown in figure 4 the head portion 3 can comprise traditional type holes 30 for the passage of the strings 41, 42. Such a head portion, with only traditional type holes, does not part of the invention as defined by the appended claims. Figure 5 shows a head portion having enlarged openings and traditional type holes. Inserts of a plastic or rubber material (known as "grommets") can advantageously be fitted into these holes, for the purpose of protecting the strings and dampening the vibrations generated by the impact of the ball on the string bed 4.
As shown in figures 5-8, the head portion 3 may comprise a plurality of enlarged openings or "ports" 31, 32, 33, 34, each of which is intended for the passage of a pair of strings 410 and/or 420.
The strings passing through each of the aforementioned enlarged openings may be adjacent longitudinal strings 410 or transversal strings 420, as shown in the aforementioned figures. In some enlarged openings, however, the passing strings may also be non-adjacent strings, for example a longitudinal string 410 and a transversal string 420.
Each of the enlarged openings 31, 32, 33, 34 has a dimension, defined by the intersection with the reference plane 40, corresponding to D = D' + 2D", where D' is the distance between two passing strings 410 and/or 420 and D" is the diameter of the two passing strings.
The enlarged openings 31, 32, 33, 34 advantageously have a substantially oval shape but may also have a different configuration, depending on needs.
Also in the presence of the aforementioned enlarged openings, the head portion 3 may also comprise traditional type holes 30 for the passage of the strings 41, 42.
The conventional holes 30 may be advantageously positioned at the segments (e.g. the corner segments) of the head portion 3, where, for obvious construction reasons, larger openings cannot be made.
The enlarged openings 31, 32, 33, 34 can also be advantageously used as seats for the insertion of plastic parts and/or vibration damping elements or for the positioning of other bodies adapted to change the weight characteristics of the head portion 3, thereby permitting, at the player's discretion, different balancing of the structure.
The enlarged openings 31, 32, 33, 34 are placed to correspond with one or more segments 35, 36, 37, 38 of the head portion 3, positioned across two quadrants adjacent to it. The head portion 3 may advantageously comprise:

first enlarged openings 31 placed to correspond with a first segment 35 of the head portion 3, positioned across the quadrants I and IV. In this case, the enlarged openings 31 are adapted to receive pairs of adjacent longitudinal strings 410; and/or
second enlarged openings 32 placed to correspond with a second segment 36 of the head portion 3, positioned across the quadrants II and III. These enlarged openings 32 are also adapted to receive pairs of adjacent longitudinal strings 410; and/or
third and fourth enlarged openings 33, 34 placed to correspond with a third and fourth segment 37, 38 respectively of the head portion 3, positioned across the quadrants I and II and quadrants III and IV. In this case, the enlarged openings 33 are adapted to receive pairs of adjacent transversal strings 420.

In the embodiment shown in figures 6-8, the head portion 3 comprises enlarged openings 31, 32, 33, 34 placed to correspond with segments 35, 36, 37, 38 and traditional holes 30 placed to correspond with the corner segments (not shown) of the head portion 3.
In the embodiment shown in figures 9-10, the head portion 3 comprises the enlarged openings 31, placed to correspond only with segment 35, and traditional holes 30, placed to correspond with the segments 36, 37, 38 and the corner segments (not shown) of the head portion 3.
Further embodiments of the present invention may feature the presence of enlarged openings placed to correspond only with the segments 35, 36, opposite each other with respect to the transversal axis X, or only with segments 37, 38, opposite each other with respect to the longitudinal axis Y.
Other embodiments of the present invention, featuring a different distribution of the aforementioned enlarged openings, are obviously possible.
The head portion 3 comprises the enlarged openings 31, 32, 33 and/or 34, and the strings 41, 42 of the string bed 4 are arranged so that the average area S_M1 of the enlarged meshes 430 formed at least partially by the strings 410 and/or 420 passing through the aforementioned enlarged openings, is 220 mm² or greater.
The average area S_M1 is given by the following equation: $S_{M 1} = \frac{\sum_{i = 1}^{P} (S_{i 1})}{P}$
where S_il is the area of the i-th mesh 430 of the string bed 4 and P is the total number of meshes 430 present on the string bed 4, formed at least partially by strings 410 and/or 420 passing through the enlarged openings 31, 32, 33 and/or 34.
Obviously, the number P is less than the total number N of meshes 43 on the string bed 4.
In these embodiments of the racquet 1, the portions (see dotted areas in figures 8 and 10) of the string bed 4 that are more often struck by the ball have meshes with a larger average area than the rest of the string bed.
This makes it possible to increase the benefits, described above, deriving from the use of a string bed 4 with enlarged meshes.
It can be seen in practice how the sports racquet according to the invention fully achieves the proposed aim and objects.
Thanks to the use of a string bed with enlarged meshes, the sports racquet according to the invention enables the player to significantly increase the power and/or rotation ("spin") imparted to the ball, while at the same time maintaining a high level of control over the shots. The player can thereby have a noticeably increased level of confidence in his sporting equipment and will be naturally inclined to force his shots more, but without losing control over them (or feeling as if he has lost control).
The use of a string bed with enlarged meshes gives the sports racquet according to the invention an aesthetically attractive appearance, easily recognizable even by inexpert users. The sports racquet according to the invention can be easily produced industrially using known molding procedures. Industrial production is therefore relatively easy and economical.
The sports racquet described above is subject to numerous modifications and variants, which may fall within the scope of the invention as defined by the appended claims.
In practice, any materials may be used, with the contingent dimensions and shapes, depending on requirements and on the state of the art.

Claims

Sports racquet (1) comprising a handle (2) and a head portion (3) adapted to support a string bed (4) comprising a plurality of longitudinal strings (41) and a plurality of transversal strings (42), said longitudinal and transversal strings (41, 42) mutually intersecting and forming a plurality of meshes, each of said meshed being enlarged and said enlarged meshes (43) having an average area (S_M) larger than or equal to 200 mm²,
wherein the average area of the enlarged meshes (43) of said string bed (4) is given by the following relation: $S_{M} = \frac{\sum_{i = 1}^{N} (S_{i})}{N}$
where S_i is the area of an i-th enlarged mesh (43) of said string bed (4) and N is the total number of enlarged meshes (43) of said string bed 4,
characterised in that said head portion (3) comprises a plurality of enlarged openings (31, 32, 33, 34) made for the passage of a pair of strings (410, 420), said enlarged openings (31, 32, 33, 34) being placed to correspond with at least one segment (35, 36, 37, 38) of said head portion, which is positioned across two adjacent contiguous quadrants of said head portion, the strings (410, 420) passing through said enlarged openings (31, 32, 33, 34) forming at least partially a plurality of enlarged meshes (430) having a larger average area (S_M1) than the average area (S_M) of the enlarged meshes (43) of the rest of the string bed,
wherein the average area of the enlarged meshes (43) formed by the strings (410, 420) passing through said enlarged openings (31, 32, 33, 34) is given by the following relation: $S_{M 1} = \frac{\sum_{i = 1}^{P} (S_{i 1})}{P}$
where S_i1 is the area of an i-th enlarged mesh (430) of said string bed (4) formed by the strings (410, 420) passing through said enlarged openings (31, 32, 33, 34) and P is the total number of enlarged meshes (43) formed by the strings (410, 420) passing through said enlarged openings (31, 32, 33, 34),
wherein the enlarged meshes (430) formed by the strings (410, 420) passing through said enlarged openings (31, 32, 33, 34) have an average area (S_M1) larger than o equal to 220 mm².
Sports racquet, according to claim 1, characterised in that said longitudinal and transversal strings (41, 42) form a plurality of enlarged meshes (43) having an average area (S_M) lower than or equal to 600 mm².
Sports racquet, according to one or more of the previous claims, characterised in that said longitudinal and transversal strings (41, 42) form a plurality of enlarged meshes (43) having an average area (S_M) comprised between 200 mm² and 250 mm².
Sports racquet, according to one or more of the claims from 1 to 2, characterised in that said longitudinal and transversal strings (41, 42) form a plurality of enlarged meshes (43) having an average area (S_M) comprised between 300 mm² and 600 mm².
Sports racquet according to one or more of the previous claims, characterized in that the diameter of said longitudinal and transversal strings (41, 42) is 1.3 mm or greater.
Sports racquet according to one or more of the previous claims, characterized in that the number of said longitudinal strings (41) is between 8 and 16 and the number of transversal strings (42) is between 8 and 18.
Sports racquet according to one or more of the previous claims, characterized in that said head portion (3) comprises traditional holes (30) placed to correspond with corner segments of said head portion.
Sports racquet according to one or more of the previous claims, characterized in that it is a racquet for tennis, squash, badminton, or racquetball.