RU2411979C1 - Tennis racket - Google Patents

Abstract

FIELD: medicine, sport. ^ SUBSTANCE: invention relates to devices for playing tennis. Tennis racket differs by construction of net, whose string surface is made with cells in form of equilateral triangles, in whose apexes three strings interlace. Technical result of the invention is achieved by the following: successive transition of strings from point of interlacement in three to adjacent point is achieved with change of string position, and position of strings in two intersections, located over a single, is similar, either extreme, or middle. Claimed are two versions of net, ensuring maximal interlacing of three rows of strings with each other. ^ EFFECT: constructive peculiarity creates symmetry of string bend in net profile, therefore shape of cells after string tension remains undistorted in plan, that is, equilateral, and net ensures the most precise ball parryingl. ^ 4 cl, 4 dwg

Description

The invention relates to devices for playing tennis.

A tennis racket is known with a grid of strings interwoven in three at points located at the vertices of an equilateral triangle, in such a way that at each of the three adjacent points of intersection of the strings their various combinations are implemented (3 or 6 in total) (application RU 2009108198). The strings of all three rows of this grid "occupy three positions in successions at the intersections: above, between, below ...", or (according to the second variant) the strings of its two rows - six positions: above, below, above, between, between, below ..., and third row - three positions: above, between, below ...

The disadvantage of this design is the partial asymmetry of the bending of the jet in the grid profile relative to the intersections of three. It arises due to the different position of the string, at intersections separated by one. So, for a grid with three combinations, any string occupying one of the extreme positions at the intersection (above or below) will occupy different positions at two adjacent intersections (one “between”, the other extreme ones — upper or lower), and only the string that has occupied middle position, will have a symmetrical bend. Thus, on the side of one adjacent intersection with the extreme position of the string, a greater bend occurs than on the opposite side, the consequence of this is the imbalance of the forces acting on the strings near their intersections from the other strings. As a result, after tensioning the mesh, its regular triangular cells are somewhat distorted, which violates the shape of the mesh and impairs the accuracy of the ball reflection.

The purpose of the invention is to increase the reliability of the grid and improve the accuracy of the ball.

The goal is achieved by interlocking three strings into a grid with cells in the form of equilateral triangles in the order that implements various combinations at adjacent vertices, so that each string occupies the same position through one suppression (either extreme or middle).

The drawings show the types of mesh and rim of a tennis racket, with two options for mesh design, an illustration of the weaving method and the output of strings through an opening in the rim.

Figure 1 shows the grid of a tennis racket with a partially stretched vertical (longitudinal) row of strings, A is a section of the string of the first (in the tension step) diagonal row. In - the second diagonal row. The grid is characterized by intersections with 4 variants of string combinations (numbered). The strings of the diagonal rows occupy the intersections at the top, between, etc., alternate with the strings of the same rows occupying the position below, between, etc., and the strings of the third row (incomplete) pass the position below, above, etc. d.

On figa shows a rim with strings at the stage of formation of the second variant of the grid device. The strings of the second diagonal row (unfinished) pass sequentially above two and under two strings, so that the strings of the first row are sequentially located two times below and two times above them.

On figb shows the grid of a tennis racket with partially stretched strings of the vertical row, implementing the second option, C is the section of the string between adjacent intersections in which it passes on one side of the strings of the diagonal row. D - for different strings. The grid is characterized by 4 variants of string combinations. The strings of the diagonal rows occupy the position above, between, below, between, etc., and the vertical row - below, above, etc. The advantage of the second option is the uniform output of the strings of all rows to the extreme positions, both upper and lower.

Figure 3 shows a view of a section of the rim 1 from the side, equipped with an opening 2 for outputting the strings (s), and strings output through it in the center 3, or from the side, above or below the center, as 4 and 5, one or one two. The diameter of the hole is two diameters of the string, which allows you to output strings two through one hole, or one at a time with the deviation of the string from the center in accordance with the position of the string at the nearest intersection. Variation of the position of the strings in the holes on the one hand does not allow excessive bending of the edge sections of the strings and distortion of the mesh, on the other hand reduces the number of holes in the rim.

The implementation of the invention. The interweaving of grids is formed in three stages. The first step is pulling the first diagonal row of the grid. The string tension at this stage is set 10-15% below the nominal, because after adding two more rows it will increase by about the same amount. The second and third stage of mesh formation consists in laying and tensioning the strings of the second diagonal and third vertical row. By “laying” a string here is meant passing the free end of the string above or below the strings of the row (s) in a certain simple sequence. The strings of the second row are stretched 5-10% below the nominal tension, and the vertical row to the nominal value.

The stage of formation of the first diagonal row, common to two options:

1. The free end of the string is passed through one of the pair of extreme holes of the rim, the string is fixed by a knot in this hole, stretched from the side of the free end, fixed in the second hole (until the tension in the next section), then the end of the string is passed through the next pair of holes, the string stretches in the opposite direction, stretches, fixed in the next section, and so on until the completion of the entire diagonal row. At the end, the end of the string is passed into the nearest prepared hole for the strings of the second diagonal row, then the sections of this row are filled with sequential weaving with the string of the first section.

Formation of the first grid option;

one.…;

2. Filling the second diagonal row begins with passing the string through the extreme pair of holes of this row on one side of the previously pulled diagonal strings (top or bottom), then the string is pulled, fixed and laid along the second section already on the other side of the strings. The laying of each subsequent section occurs similarly with a change of position. After fixing the last string, its free end is passed into the nearest hole from a pair of extreme vertical rows;

3. The strings of the vertical row are laid alternately above / below the intersections of two diagonal strings located on the vertical. After tensioning and fixing, the string passes the rim in the opposite direction and is laid, starting from the same position as in the last intersection of the previous section, if the first intersection of the new section and the last of the previous section are connected by a string from the first diagonal row (A), or from the opposite position if they are connected by a string from the second diagonal row (B).

The formation of the second grid option:

one.…;

2. Filling the second diagonal row begins by pulling the string through one of the pair of extreme holes and laying it successively two times from the bottom and two times from above the strings of the first dr., With the string output through the second hole of the pair and fixation after tension. Next, the string is laid through the second section, in the following order:

“Up-up-down-down-”, if on the same vertical line (shown by an arrow) with the first intersection of a new section there is an intersection of the previous section with the string position “down”, going on this section after crossing with a position “down”;

“Up-down-down-up-”, if the node “down” after “up” is in the same place;

"Down-down-up-up-" if "up" after "up"

“Down-up-up-down-” if “up” after “down”

In the same way, all even strings in a row are laid.

The third and each odd string is laid in the following order:

“Up-up-down-down-”, if on the same vertical line with the first intersection of the new section there is the intersection of the previous section with the string position “down”, going on this section after crossing with the position “down”;

“Up-down-down-up-”, if the node “up” after “down” is in the same place;

"Down-down-up-up-" if "up" after "up"

“Down-up-up-down-” if “down” after “up”

In the same way, all the odd strings in a row are laid.

If on the same vertical line with the first intersection of the new section there is no intersection of the previous section, then they represent it, mentally continuing the strings beyond the contour of the rim;

3. Strings of a vertical row are laid alternately above / below the intersections of two diagonal rows of strings located on the same vertical. After pulling and fixing in the first section, the string passes a new section in the opposite direction and is laid alternately above / under the intersections, starting from the opposite position, that at the last intersection of the previous section, if the first intersection of the new section and the last of the previous one are connected by a string (C) passing along one side of the strings of the diagonal row, and starting from the same position if they are connected by a string (D) running on opposite sides.

An example of a tennis racket. Tennis rackets with a net of strings (strings) with a diameter of 1.2 mm, which are intertwined at the vertices of an equilateral triangle with a side of 22 mm according to the claimed options. The proposed net has 1.5-2 times greater rigidity, contributes to a strong and accurate ball serve, as well as a more confident reflection of the ball. The string adhesion for both variants increases by 20–25% due to the greater degree of string bending I (the ratio of the sum of the string displacements at each transition to the distance between the extreme intersections). In the proposed meshes, the degree of bending is maximum for a given ratio of the diameter of the strings to the side of the cell and is equal to: I = 4 / 3d / l = 0.07, where d / l is the ratio of the diameter of the string to the side of the cell or the linear filling of the grid. The symmetry of the bending of strings in the mesh profile ensures the preservation of the correct shape of the mesh.

Claims (4)

1. A tennis racket including a handle, a transitional part, a rim, holes in it and a net consisting of three rows of strings intersected at the vertices of equilateral triangles in three in the order that implements different combinations of strings at the vertices of each cell, differing in the same position of the strings at the intersections located through one, and alternating the lower and upper positions of the strings of one of the rows at their intersections. 2. Tennis racket according to claim 1, characterized in that with a part of the strings of two rows, occupying the intersections sequentially at the top, between, repeated through one intersection, broken with the other part of the strings of the same rows, occupying the position at the bottom, between, repeating through one. 3. Tennis racket according to claim 1, characterized in that with the strings of two rows, occupying the intersections in sequence, the position is at the top, between, at the bottom, between, repeating in three. 4. Tennis racket according to claim 1, characterized in that it differs in the diameter of the holes of the rim for outputting the strings of the net equal to at least 2 diameters of the string.

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