RU188211U1 - Tennis racquet - Google Patents

Abstract

The invention relates to sports equipment, in particular to tennis or badminton racquets. The technical result is to provide an adjustable reduction in the moment of inertia at the time of the strike. This is achieved by the fact that the tennis racquet contains a handle and a hollow rim connected to it with tensioned strings, inside which is symmetrical about the longitudinal axis with the ability to move two weights are placed, connected by rods with a means of shifting them to the handle. In this case, the rods are equipped with a trigger mechanism, and the weights are equipped with a means of moving them to the top of the rim. 2 ill.

Description

The invention relates to sports equipment, in particular to tennis or badminton rackets.

Known tennis racket with adjustable balance (CN 202438085 [1]). The racket contains a handle connected by a fork to the rim, in which threaded holes are made for tightening screws. By screwing in or out, you can change the balance of the racket to the needs of the player. A disadvantage of the known racket is the inability to change the balance during the game, for example at the time of striking the ball.

Known tennis racket with a variable moment of inertia (CN 201244324 [2]). The racket comprises a handle connected to a rim in which threaded holes are made symmetrically with respect to the longitudinal axis for tightening the screws. By screwing in or out, you can change the moment of inertia of the racket. A disadvantage of the known racket is the inability to change the balance during the game, for example at the time of striking the ball.

Known tennis racket with adjustable center of gravity during the game (CN 105013155 [3]). The racket contains a handle connected to the hollow rim, inside which mercury can move, some of which is poured into the container in the handle, and the container is connected to the hollow rim. A disadvantage of the known racket is that at the time of striking the mercury due to inertia forces it moves to the head of the racket, which significantly increases the moment of its inertia, which in turn requires considerable effort from the player. In addition, the use of mercury is very risky. During the game, the player often touches the surface of the court at the moment of impact, which leads to damage and even destruction of the racket and can lead to the spill of mercury.

Known racket containing a handle connected by a fork to the rim, and means for changing the distribution of the weight characteristics of the head of the racket (DE 10060457 [4]). The said means is two weights symmetrically placed in the hollow rim attached to the toothed plastic belts, which are engaged with the gear fixed in the lower part of the rim. When the wheel rotates, the weights synchronously move inside the rim, changing the weight distribution over the rim and thereby balancing. A disadvantage of the known racket is the inability to change the balance during the game or change the moment of inertia of the racket. For example, at the time of striking the ball.

Known tennis racket with an adjustable center of gravity (CN 104623875 [5]). The racket contains a handle connected to a hollow rim, inside of which a magnetized weight can move. Electromagnetic coils are mounted on the rim, connected via switches mounted on the handle to an electric power source located inside the handle. By supplying current to one or another coil, it is possible to ensure the movement of the weight inside the rim and fixation in the selected coil. A disadvantage of the known racket is the inability to change the balance during the game.

Closest to the claimed is a tennis racket known from the description to FR 2856310 [6], which allows you to instantly, during the game, change the balance of the racket. The racket comprises a handle and a hollow rim connected to it with tensioned strings. Two weights are placed symmetrically relative to the longitudinal axis inside the hollow rim, and the mechanism for their return to the initial state in the form of ends of rods connected to the weights thrown over a double pulley installed between the rim and the handle, equipped with a flat spiral spring. At the time of striking a racket under the influence of inertia, the weights move to the head of the racket’s rim (there is a “balance to the head”), which increases the power of the strike. After its completion, the weights under the influence of a spring stretched at the time of impact, the springs return to their original position. A disadvantage of the known racket is that during the game, at the time of the strike, it increases the moment of inertia due to the displacement of the weights to the head of the racket and the weights return to their original state only after the strike is completed. But in the process of the game often there is a need to lighten the head part when striking, and the well-known racket does not provide this.

The inventive tennis racket is aimed at providing an adjustable reduction in the moment of inertia at the time of the strike.

The indicated result is achieved in that the tennis racket comprises a handle and a hollow rim connected to it with tensioned strings, inside of which two weights are connected symmetrically with respect to the longitudinal axis and connected by rods with a means of shifting them to the handle. In this case, the rods are equipped with a trigger mechanism, and the weights are equipped with a means of moving them to the top of the rim.

The specified result is also achieved by the fact that the means of shifting the weights to the handle is made in the form of a spiral spring connected to the rods placed in the handle.

The indicated result is also achieved by the fact that the trigger mechanism is made in the form of a lever releasing a spiral spring stretched in the handle.

The specified result is also achieved by the fact that the means of shifting the weights to the handle is made in the form of an electromagnetic relay connected to the rods of the core, placed together with the current source in the handle.

The indicated result is also achieved by the fact that the trigger mechanism is made in the form of a switch mounted between the electromagnetic relay and the current source in the handle.

The specified result is also achieved by the fact that the means of moving the weights to the top of the rim is made in the form of spiral springs.

The indicated result is also achieved by the fact that the means of moving the weights to the top of the rim are made in the form of rubber bands. The indicated result is also achieved by the fact that the means of moving the weights to the top of the rim are made in the form of cores of electromagnetic relays connected by conductors to a current source placed with in the handle.

Distinctive features of the claimed tennis racket are:

- traction connecting the weights with a means of shifting them to the handle is equipped with a trigger;

- the weights are equipped with a means of moving them to the top of the rim;

- a means of shifting the weights to the handle is made in the form of a spiral spring connected to the rods located in the handle;

- the trigger mechanism is made in the form of a lever releasing a spiral spring stretched in the handle;

- the means of shifting the weights to the handle is made in the form of an electromagnetic relay connected to the rods of the core, placed together with the current source in the handle;

- the trigger mechanism is made in the form of a switch mounted between the electromagnetic relay and the current source in the handle;

- means of moving weights to the top of the rim is made in the form of spiral springs;

- a means of moving the weights to the top of the rim is made in the form of rubber bands;

- the means of moving the weights to the top of the rim is made in the form of cores of electromagnetic relays connected by conductors to a current source located with in the handle.

The supply of rods connecting the weights with the means of shifting them to the handle by the trigger mechanism allows the player to ensure the movement of the weights to the handle of the racket at the right time, which will lead to a decrease in the moment of inertia of the racket and thereby increase the speed of the racket head. This obviously follows from the law of change in the moment of momentum of a rigid body (see LD Landau, EE Livshits "Theoretical Mechanics"):

- момент силы, в нашем случае с которой теннисист действует на ракетку, Y - момент инерции ракетки,

- угловое ускорение ракетки. Для каждого конкретного теннисиста

таким образом уменьшая Y в процессе разгона ракетки можно увеличить

и соответственно, скорость ракетки. Перемещение грузиков к ручке ракетки во время разгона, как раз и приводит к уменьшению Y, т.к. Y~m R2, где m - масса ракетки, R - расстояние от центра масс до кончика ручки, которое уменьшается при движении грузиков к ручке. Снабжение грузиков средством перемещения грузиков к вершине обода позволяет вернуть грузики к голове ракетки после совершения удара или при необходимости утяжелить голову. Это позволяет менять баланс ракетки в статическом режиме.here

is the moment of force, in our case with which the tennis player acts on the racket, Y is the moment of inertia of the racket,

- angular acceleration of the racket. For each specific tennis player

thus decreasing Y during the acceleration of the racket can increase

and accordingly, the speed of the racket. Moving the weights to the racket handle during acceleration, just leads to a decrease in Y, because Y ~ m R2, where m is the mass of the racket, R is the distance from the center of mass to the tip of the handle, which decreases when the weights move to the handle. Providing the weights with a means of moving the weights to the top of the rim allows you to return the weights to the head of the racket after the strike or, if necessary, make your head heavier. This allows you to change the balance of the racket in static mode.

Means for shifting the weights to the handle can be made in various ways. For example, in special cases it can be in the form of a spiral spring connected to the rods, placed in the handle or in the form of an electromagnetic relay connected to the rods of the core, placed together with the current source in the handle. Accordingly, the trigger mechanism that starts moving the weights to the handle can be made in the form of a lever releasing a spiral spring stretched in the handle or in the form of a switch mounted between an electromagnetic relay and a current source in the handle. Also, a means of moving the weights to the top of the racket of the racket can be performed in various ways. It can be spiral springs, rubber bands, cores of electromagnetic relays connected by conductors to a current source located with in the handle.

The essence of the claimed tennis racket is illustrated by examples of implementation and graphic images. In FIG. 1 is a schematic general view of a racket with mechanical means for moving weights. In FIG. 2 is a schematic general view of a racket with electromechanical means of moving weights.

Example 1

Tennis racket contains a handle 1 and a hollow rim 3 connected to it with tensioned strings 2, inside of which two weights 4 are connected symmetrically with respect to the longitudinal axis 4 connected by rods 5 with the means of their displacement to the handle, which is made in the form of a spiral spring 6, equipped with a trigger a mechanism in the form of a lever 7. The weights are equipped with means 8 for moving them to the top of the rim, which can be made in the form of spiral springs or rubber bands, one ends of which are connected to the weights, and the second fixed by a latch 9 in the head of the racket.

The racket is used as follows.

In the initial position, the spring 6 (Fig. 1) is stretched and fixed using the lever 7. After swinging the racket, in the process of dispersal, the tennis player presses the lever 7, the spring 6 is compressed, the weights 4 are moved using the rods 5 to the handle of the racket, the moment of inertia of the racket decreases, and the speed increases, so the spring energy passes into the kinetic energy of the racket. After the impact, the spring is again stretched by the player using the lever 7 and is fixed, the weights 4 by the strands (or springs) 8 return to their original position and the racket is ready for the next impact.

Example 2

Tennis racket contains a handle 1 and a hollow rim 3 connected to it with tensioned strings 2, inside of which two weights 4 are connected symmetrically with respect to the longitudinal axis 4 connected by rods 5 with the means of their displacement to the handle, which is made in the form of an electromagnetic core 10 connected to the rods relay 11, placed together with the current source 12 in the handle. The racket is equipped with a trigger made in the form of a button 13 installed in the handle. The weights are equipped with a means for moving them to the top of the rim, which can be made in the form of cores 14 of electromagnetic relays 15, rigidly fixed inside the rim and connected by conductors (not shown) to a current source located in the handle. Weights are connected to the cores by 14 rods 16.

The racket is used as follows.

After a swing, during the acceleration, the tennis player presses the button (switch) 13, the voltage is supplied from the current source 12 to the electromagnetic relay 11, the heart of which is pulled towards the end of the racket, the weights 4 are shifted to the handle using rods 5, which reduces the moment of inertia rackets and, accordingly, to increase its speed, i.e. the electrical energy of the battery goes into the kinetic energy of the racket. After the strike, the tennis player stops pressing the switch 13, the relay 11 is de-energized, the core with the help of the springs contained in it is returned to its original position, and the weights 4 are returned to their original position using rods 16 and electromagnetic relays 15.

It is worth noting that the racket can also be controlled remotely by means of a processor mounted in the handle, which will track the start of the racket’s acceleration. As soon as the racket picks up a predetermined threshold speed, the computer sends a command to the relay and everything further, as described above.

Claims (8)

1. A tennis racket containing a handle and a hollow rim connected to it with tensioned strings, inside of which two weights are placed symmetrically with respect to the longitudinal axis, connected by rods with a means of shifting them to the handle, characterized in that the rods are equipped with a trigger mechanism, and the weights equipped with a means of moving them to the top of the rim. 2. Tennis racket according to claim 1, characterized in that the means for shifting the weights to the handle is made in the form of a spiral spring connected to the rods located in the handle. 3. A tennis racket according to claim 2, characterized in that the trigger is made in the form of a lever releasing a spiral spring stretched in the handle. 4. Tennis racket according to claim 1, characterized in that the means of shifting the weights to the handle is made in the form of an electromagnetic relay connected to the rods of the core, placed together with the current source in the handle. 5. Tennis racket according to claim 4, characterized in that the trigger mechanism is made in the form of a switch mounted between an electromagnetic relay and a current source in the handle. 6. Tennis racket according to claim 1, characterized in that the means of moving the weights to the top of the rim is made in the form of spiral springs. 7. Tennis racket according to claim 1, characterized in that the means of moving the weights to the top of the rim is made in the form of rubber bands. 8. Tennis racket according to claim 1, characterized in that the means of moving the weights to the top of the rim is made in the form of cores of electromagnetic relays connected by conductors to a current source located in the handle.

Images