RU2394620C1 - Tennis racket - Google Patents

Abstract

FIELD: health, sports. ^ SUBSTANCE: tennis racket includes handle, transition part and rim with net, which consists of strings crossed in triangle tops by three. Strings cross at the angle of 60 degrees in the order, which realises various combinations of strings in tops of each cell with side equal to 16-20 diametres of string, with total number of combinations equal to 3 or 6. ^ EFFECT: using invention makes it possible to improve stiffness of net with reduction or preservation of strings tension, to increase strength of net with preservation of net aerodynamic properties, to prolong service life due to their stabilisation in net units and to improve friction contact of net and ball. ^ 3 cl, 16 dwg

Description

The invention relates to the field of sports, namely, devices for playing tennis.

Known tennis racket, consisting of a handle, adapter and rim with a net of strings made in three rows located at different angles at different levels (RU 2203713).

Another tennis racket has a geometrically regular net formed of strings intertwined in two in nodes located at the vertices of the triangles and adjacent hexagons (US 4184679 and US 6089997).

Such a grid design has good stiffness and cohesion characteristics of the strings in nodes, however, due to the fact that the grid is characterized by the presence of hexagons, it must be stretched from frequently arranged strings so that excessively large cells do not appear, which does not improve aerodynamic properties and create grids with the desired rigidity.

Known tennis rackets with nets consisting of three systems of interwoven strings, in particular, a tennis racket according to US 323608 has a well-known square mesh with a woven diagonal string in the nodes located at the vertices of the square. The disadvantage of this design is the irregularity of the cells - the cells of such a racket are in the form of rectangular triangles.

Inventions are known in which the third string is added only at the periphery of the string surface, and the central region is formed by a grid with two string systems interlaced at right angles (US 971773).

In light industry, triaxial fabrics are used. In such a fabric, two weft yarns are interwoven with warp yarns at an angle of 60 or 45 instead of 90 ° with the traditional method of dressing the fabric. The interweaving of these fabrics is carried out by a lattice in the form of regular triangles.

The closest analogue of the claimed invention is a tennis racket net US 4231575, Fig.3. The net of this tennis racket is an interweaving of transverse and two systems of diagonal strings, stretched symmetrically at an angle of 70-75 ° to the longitudinal strings. Strings completely overlap each other only in the so-called the hexagonal plane, where they are interwoven in three or two, the rest of the string surface is made by interlacing two systems of strings or without interlacing.

The disadvantage of this design is the chaotic order of interweaving of strings in the hexagonal region, as well as incomplete overlapping of string strings.

The objective of the invention is to improve the rigidity of the mesh while reducing or maintaining the tension of the strings, increasing the strength of the mesh while maintaining the aerodynamic properties of the racket, extending the life of the strings due to stabilization at the nodes of the mesh, and also giving the front of the string surface a rougher character, which allows to improve the frictional contact of the mesh and the ball and increase the adhesion of the net to the ball during oblique impacts.

The technical result, which consists in eliminating these shortcomings in a tennis racket, including a handle, a transitional part and a rim with a net consisting of strings crossed at the vertices of a triangle by three, is achieved by crossing the strings at an angle of 60 degrees in the order that implements at the vertices of each cell, with side equal to 16-20 diameters of the string, various combinations of strings with a total number of combinations equal to 3 or 6. A tennis racket can have a net with three combinations of strings, in which the strings of each row are occupied at intersections The sequence of three positions: top, middle, bottom, repeated through two intersections.

A tennis racket can have a net with six string combinations, in the net of which the strings of one row occupy the intersections sequentially above, in the middle, below, repeating through two intersections, and the strings of the remaining rows pass intersections with six combinations and occupy positions in them in the sequence: in the middle, above, below, above, below, in the middle, repeating in five.

By the geometrically correct order of interweaving the strings of the grid, we mean the arrangement of combinations of three strings in the nodes of the lattice, in which it is possible to select some elementary fragment (motive) in it with the regular arrangement of combinations in the nodes, by which you can restore the entire grid, resorting to parallel transfer. By string combination in a knot we mean the order in which the strings form a knot-weave. For example, the combination ABC means that in this node the strings of row A and C are between the string of row B, string A is at the top, and B is at the bottom.

Generally speaking, an unlimited number of endless nets with cells in the shape of a triangle and several tens of nets that can be formed in the contour of the rim of a tennis racket is possible. They have their own unique motive, but only a small number of them have a simple motive. When complicating the motive, the degree of string weaving inevitably decreases, which worsens the work of the grid. Only a small number of variants of regular grids realize the maximum possible degree of string interweaving, which can be expressed by the degree of bending of the string in the grid; it can be quantified by the ratio of the sum of the displacements of the string at each transition between nodes to the distance between the extreme nodes. Under conditions of uniform tension of the mesh, it is obvious that when a string moves from one extreme position to another, the extreme displacement is two string diameters, and when passing from a middle to one of the extreme ones, the diameter.

Thus, the claimed mesh were developed with the condition:

1. maximum degree of bending strings. In the variants of mesh weaving that we offer, the total value of the bending of the mesh strings is a geometric limit equal to 1.33 of the linear filling of the mesh.

2. With the condition that there are no or minimum transitions of the string between adjacent nodes in which they do not change their position.

3. With the same sequence of positions occupied by strings for at least two rows.

The order of string interweaving in the claimed grids should obviously be such that in any three adjacent nodes (belonging to the same cell) the strings are arranged with a different combination, and the total number of string combinations in the grid can be from three (minimum number) to six (maximum )

The drawings show a General view of a tennis racket, device options and illustrations of the method of weaving the net.

Figure 1 shows a tennis racket consisting of a handle 1, a transitional part 2, a rim 3 with holes for holding a net 4 formed by interlacing the strings of two diagonal rows 5 and a vertical row 6. The strings are interlaced in three at points located at the vertices of the equilateral a triangle with a side of 16-20 diameters of the string, in such an order that in each of the three adjacent points of intersection of the strings their various combinations are realized.

On figa shows a rim with strings at the stage of formation of the first embodiment of the grid device. This shows the interweaving of two diagonal rows, 1 and 2 — a pair of holes in the rim through which a string is laid at the extreme end of the diagonal row and fixed in hole 1 by a knot 3; 4 and 5 - a pair of holes in the next section of the position, 6 - hole through which the string enters the first section of the second diagonal row. The strings of the second diagonal row pass sequentially above the two and below the third string so that the strings of the first row pass sequentially in the second row, located twice below and once above them.

On figb and presents the first variant of the device mesh, stretched in the lower half of the rim, a fragment of the mesh according to the same variant, characterized by three combinations of strings in nodes, in which the strings of each of the three rows occupy three positions in turn: upper, lower, middle ..., as shown in section AA. The numbers on the nodes number the types of nodes according to the combination of strings: 1 - ABC. 2 - BCA. 3 - SAV.

Hereinafter, A, B are the strings of the diagonal rows, C are the strings of the vertical row (laid along the axis of the rim), the order of the letters corresponds to the position of the strings in the knot from top to bottom.

Figure 2c below shows a grid motif — an arrangement of nodes with corresponding types of string combinations.

On Figg shows a side view of the racket.

On figa shows a second variant of weaving at the stage before pulling the strings of the vertical row. The grid according to this option has six combinations of strings in nodes that are indicated by numbers: 1 - ACB, 2 - CAB, 3 - ABC, 4 - BAC, 5 - BCA, 6 - CBA. The strings of the vertical row pass sequentially three types of nodes 1, 2, 3 alternating with strings passing nodes 4, 5, 6 and occupy the nodes sequentially above, in the middle, below. The strings of the diagonal rows pass through nodes with six string combinations in the sequence 142536 ... and 163524 ... and occupy successively the middle, upper, lower, upper, lower ... positions, as shown in section BB.

On figb shows the motive of the grid according to the second embodiment.

Fig. 4a shows a rim with tensioned strings of one diagonal row and with stowed strings of the second, occupying alternately positions all the time under and all the time above the strings of the first row.

On figb shows the grid of a tennis racket to the tension of the strings of the vertical row, implementing the third option. The net is characterized by 4 types of string combinations: 1 - CAB, 2 - BAC, 3 - CBA, 4 - ABC, with strings of rows A and B in an upward position, between ... that alternate with strings of the same rows in a downward position, between ..., and strings of row C, always occupying a position: below, above ....

Figure 4c shows the motif of this grid.

On figa shows a rim with strings at the stage of forming the mesh of the fourth variant of the device. The strings of the second diagonal row pass sequentially above two and under two strings, so that the strings of the first row pass sequentially in the second row, located twice under and two times above them.

On figb shows the grid of a tennis racket with partially stretched strings of the vertical row, implementing the fourth option. The net is characterized by 4 types of string combinations: 1 - CAB, 2 - ABC, 3 - BAC, 4 - CBA, with strings of rows A and B, occupying the positions top, middle, bottom, middle, etc., and with strings C, occupying position: bottom, top, etc.

Examples of meshing of the claimed tennis racket

The claimed options for interweaving grids are formed by the following sequence of operations. The first step is pulling one of the two diagonal rows of the grid. In this case, the string tension is set 10-15% below the nominal, since after adding two more string systems it will increase by about the same amount. The second and third stages of mesh formation consist of 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 diagonal strings in a certain simple sequence: either above, below or between the strings of both diagonal rows (for the final stage). The strings of the second row are stretched to a voltage of 5-10% below the nominal, and the vertical row to the nominal value.

The first stage of the formation of grids is common to all options (see figa).

1. The free end of the string is passed through the hole in the rim 1 and 2 from the extreme pair of holes of the first diagonal row, fixed by a knot 3 in the first hole, stretched from the side of the free end, fixed in hole 2 until the string is tensioned or fixed in the next section, then the end the strings are passed through the next pair of holes 4 and 5 of this diagonal row in the opposite direction; the string is pulled, fixed and so on until the entire diagonal row is filled.

At the end, the end of the string is passed into the nearest hole 6 from a pair of extreme holes of the second diagonal row, then the sections of the second diagonal row are filled with sequential weaving with the string of the first diagonal row. Upon completion of filling the sections of the second diagonal row with the string, the free end is passed through the nearest of the holes of the extreme pair of the vertical row and the strings of the last row are woven similarly.

The formation of the first variant of the grid (figa, 2b)

one…

2 - Filling the second diagonal row begins with pulling the string through one of the pair of extreme holes of this row and passing it sequentially once from the bottom and two times in a row from above the strings of the first dr., With the string output through the second hole of the pair and fixation after tension. The string passes the next section in the opposite direction and occupies positions relative to the transverse strings in the sequence:

“Bottom-up-up ...”, if on the same vertical line with the first node of the new section there is a node of the previous section with the position of the interwoven string “above”, going on this section after the node with the position “below”;

“Up-down-up ...” if at the same place there is a node “up” after “up”;

"Up-up-down ..." if ... "down."

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

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

“Bottom-up-up ...” if on the same vertical line with the first node of the new section there is a node of the previous section with the string position “up”, coming after the node with the position “up”;

“Up-down-up ...” if the node “at the bottom” is in the same place;

"Up-up-down ..." if ... "up" after "down".

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

3. After filling in the second dr. the string is passed through one of the holes of the extreme pair of the vertical row and laid through the knots on this vertical with the weaving in them in the sequence "at the bottom of the knot - between the strings of the knot - at the top of the knot ...", starting from the position:

“Top”, if the initial and second nodes along the course of laying the strings are identical in position of the diagonal strings;

“Between” if the same second and third nodes;

“Bottom” if the third and fourth nodes are the same.

The free end is pulled out of the second hole, the string is pulled and fixed. The next and every even section is laid likewise in the opposite direction in the sequence “above-between-below ...”, starting

from the “top” position, if the future node is adjacent to the node of the previous section with the “bottom” position;

from the “between” position, if the future node is adjacent to the node with the position “above”;

from the “bottom” position, if the future node is adjacent to the node with the “between” position.

The third and every odd section is laid with weaving in the sequence “bottom-between-top ...”, starting

from the “top” position, if the future node is adjacent to the node with the “between” position;

from the “between” position, if the future node is adjacent to the node with the position “below”;

from the “bottom” position, if the future node is adjacent to the node with the “top” position.

After filling the vertical row to the middle of the first knot in the new section, two adjacent nodes from the previous section appear, in this case weaving begins depending on the position of the string in the node adjacent to the strings of the first diagonal row for an even vertical row and the second dr. for an odd series, similar to the above.

The formation of the second variant of the grid (figa)

one.…

2. Filling the second diagonal row begins with pulling the string through one of the pair of extreme holes and passing it alternately from above / below the strings of the first dr. with the conclusion of the string through the second hole of the pair and fixation after tension. Next, the string is sequentially laid through the next section in the same sequence, starting from the position opposite to the position occupied in the last formed node in the previous section, if the new and existing nodes are adjacent, i.e. make up the side of one rhombus, and starting from another position, if the future node is not adjacent to the existing one.

3. Strings of the vertical row are laid through one of the holes of the extreme pair of the vertical row, nodes on the vertical with weaving in the sequence “bottom-between-top” and the second hole; the free end is pulled out, the string is pulled and fixed. The next and every even section is laid likewise in the opposite direction in the sequence “up-between-down”, starting

from the “top” position, if the future node is adjacent to the node with the “bottom” position;

from the “between” position, if the future node is adjacent to the node with the position “above”;

from the “bottom” position, if the future node is adjacent to the node with the “between” position.

The third and every odd section is laid with weaving in the sequence “bottom-between-top”, starting

from the “top” position, if the future node is adjacent to the node with the “between” position;

from the “between” position, if the future node is adjacent to the node with the position “below”;

from the “bottom” position, if the future node is adjacent to the node with the “top” position.

After filling the vertical row to the middle, a situation arises when two adjacent nodes from the previous section appear at the first node in a new section, in this case weaving begins depending on the position of the string in the node adjacent to the strings of the first diagonal row for an even row and the second q. R. for an odd series, similar to what was stated earlier.

The formation of the third variant of the grid (figa, 4b)

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 stretching of each subsequent section occurs similarly to a change of position. After fixing the last string from the second row, the free end is passed into the nearest hole from a pair of extreme vertical ones.

3. The string of the vertical row is laid alternately above / below the nodes-weaves of two systems of diagonal strings located on this vertical. After pulling and fixing, the string passes the rim in the opposite direction and is woven into the nodes in the same order, starting from the same position as in the last node of the previous section, if the first node of the new section and the last of the previous one are connected by a string from the second diagonal row, or - from the opposite position, if they are connected by a string from the first diagonal row.

The formation of the fourth variant of the grid (figa, 5b)

one. …

2. Filling the second diagonal row begins with pulling the string through one of the pair of extreme holes and passing it sequentially two times in a row from the bottom and two times in a row 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 next section, starting in the following sequence

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

“Up-down-down ...” if the node “down” after “up” is located at the same place;

"Down-down-up ..." if "above" after "above";

“Down-up-up ...” 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 sequence:

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

“Up-down-down ...” if the node “at the top” after “at the bottom” is in the same place;

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

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

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

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

3. The strings of the vertical row are laid alternately above / below the nodes formed by two diagonal rows of strings located on the vertical of the first section of the row. After pulling and fixing, the string passes in the opposite direction and is laid between nodes with the same alternation, occupying the opposite position in the first node of a new row, as in a node in which the combination of strings of diagonal systems was the same until the third string was woven. On figb it is seen that the string in the first and odd sections of the vertical row is passed over the node type 1 and under the node type 2, and in the second and even sections - under the node 1 and above node 2.

Tennis Racket Example

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 more confident ball reflections not only in the central region, but also in the periphery. String grip for a variant with three and four string combinations is increased by 25%, for a variant with six string combinations - by 35% compared to the prototype grid. The symmetry of the arrangement of nodes with different combinations of strings provides a more accurate reflection of the ball.

Information sources

http://wwwl.fips.ru/wps/wcm/connect/content_ru/ru/inform_resources/inform_retrieval_system/;

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Claims (3)

1. Tennis racket, including a handle, a transitional part and a rim with a net consisting of strings intersected at the vertices of a triangle by three, characterized by the intersection of strings at an angle of 60 ° in the order that implements at the vertices of each cell, with a side equal to 16-20 diameters strings, various string combinations with a total number of combinations equal to 3 or 6. 2. The tennis racket according to claim 1, characterized by a grid with three string combinations, in which the strings of each row occupy three positions in intersections in sequence: above, in the middle, below, repeating through two intersections. 3. The tennis racket according to claim 1, characterized by six string combinations, in the grid of which the strings of one row occupy the intersections sequentially above, in the middle, below, repeating through two intersections, and the strings of the remaining rows pass intersections with six combinations and occupy them positions in the sequence: in the middle, above, below, above, below, in the middle, repeating in five.

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