EP0035253A1 - Training device for the art of tennis - Google Patents

Abstract

A training device for practising the most varied tennis strokes in all directions and strengths has a bar (1) which is provided at one end with a ball (18) and is rotatable at the other end about an axle (3) and between lateral guide discs (11, 11') and is provided with at least one fastening means (4), which is arranged to the side of a lateral guide disc (11) and preferably perpendicular to the axle (3), and with a resetting device (2) for the bar (1). For this purpose, the bar (1) is connected to a spring member (2) and each fastening means (4) is connected to at least one spring member (2) which can be arranged on the bar (1) at varying distances from the axle (3). Additionally, one lateral guide disc (11 or 11'), being axially displaceable, can exert a braking force on the bearing of the bar, which bearing is rotatable about the axle, via a force introduced by at least one spring member (2). <IMAGE>

Description

The invention relates to a tennis technique trainer according to the preamble of claim 1. Such a tennis technique trainer is known from DE-OS 29 11 146.

From DE-OS 25 06 341 it is known, for example, that a rod has a ball at one cranked end and is resiliently clamped at the other end, tennis strikes hitting the ball causing the rod to pivot about an intermediate pivot point, which in both Counteract spring forces attacking swivel directions. Compared to this state of the art, a state of the art known from US Pat. No. 3,876,203 has two additional degrees of freedom due to a corresponding gimbal mounting, without solving the inherent disadvantage that a slight change in the acting spring forces enables adaptability to different impact strengths.

From US-PS 39 48 517 a device for hitting a tennis ball with a racket surface is known, which consists essentially of a U-shaped frame part, which serves as a hit surface for the racket surface, and from a suspended on a pendulum There is a tennis ball. The eye of this pendulum is located between two spacers, on the outside of which arms are provided, which limit the path of movement of the struck ball. A space is provided between these arms through which a properly struck ball can pass without colliding with these arms. However, a poorly struck ball is caught by these arms. This device is thus only used to hit the ball in the correct plane or in the right direction, so that it can either catch the ball or pass through. It is not possible to dose the stroke strength or slow down and quickly reset the ball with this device.

The US-PS 36 01 398 describes a tennis technique exercise device in which a tennis ball is suspended on an axis via a pendulum. After hitting the ball, this pendulum rotates several times around the axis, since there is no possibility of braking or damping. Longer striking times must therefore be expected until the striking repetition; in addition, there is no possibility of practicing special punches.

From US-PS 41 05 203 a tennis trainer is known, which consists essentially of an L-shaped arm as a ball holder, which is rotatably mounted in the horizontal plane on a carrier and can be returned to the starting position via a return element, for example springs . This device is only suitable for practicing forehand and backhand strokes, while all strikes that pass through a horizontal plane cannot be practiced with this device. This eliminates praise or topspin or slice strokes; furthermore, force-graded blows cannot be learned due to lack of dosing ability of the restoring force of the arm.

From FR-PS 22 32 339 a device for learning the tennis technique is known in which an arm mounted vertically on a support frame is equipped with a ball. This ball moves downwards along a vertical plane when struck and is moved back to the starting position after the impact on an elastic member at the lower vertex. With this device, which is no longer of the generic type, only forward and backhand strokes, but not complicated strokes from bottom to top or from top to bottom, can be practiced. There is also no grading of the impact force by metering the damping.

The exercise device described in US-PS 40 89 521 is similar in principle to the device according to FR-PS 22 32 339, since here also a ball attached to a rod is knocked down and is retrieved via a spring. The same disadvantages mentioned above apply to this device.

From FR-PS 15 63 013 a device for practicing tennis is known, in which the tennis ball is attached to a support device via a curved arm and a roller bearing. This roller bearing ensures the free rotation of the arm, which is otherwise not braked or damped.

The US-PS 26 06 025 describes a device for ball games, including for tennis. In this device, a ball is suspended from an arm via a pendulum in which an energy-storing coil spring is arranged. When the ball is hit and the pendulum rotates around the arm, the coil spring is tensioned and stores the energy. This process counteracts the ball movement, so that it after completion of this forward movement there is a backward movement of the ball suspended on the pendulum. This device dampens the movement of the ball and ultimately brakes it. Due to the lack of lateral guidance, however, the pendulum can break out to the side, so that there are considerable time delays in the resetting due to the tumbling movement of the pendulum. Furthermore, the numerous forward and backward rotations considerably delay the usability of this exercise device, the rest position of the pendulum being difficult to achieve due to the lack of locking elements.

The invention has for its object to provide a tennis technique trainer with which all striking techniques can be learned by varying the angular arrangement and the spring force of the rod, high exercise frequency to be achieved on this device with a simple structure and easy assembly.

This object is achieved in accordance with the characterizing part of claim 1.

With the device according to the invention, all striking techniques used in tennis can be learned on just one device. So praise, slice and topspin strokes can also be as simple pre- and Rückhandschlä ^g e learned. Due to the height adjustability of the device, any striking positions can be simulated, ranging from the striking positions located just above the ground to the butterflies or striking position.

Since the rod is fastened to a spring element which is arranged between two fastening rods which are fixedly connected to the axle, the rod can pass through Rotate the axis at any angle to the support plane, ie the rigid rod can be transferred continuously from the vertically hanging position, for example to the horizontal or vertical position. A corresponding, changeable cranking of the rod ensures that the racket does not hit the rod when the ball is struck, so that all orientations of the racket surface with respect to the ball are possible.

By choosing springs, for example rubber bands or coil springs, with different spring characteristics, a certain pretension of the rod can be generated, which the player has to overcome, whereby he can choose from a soft to a very hard hit ball. Due to the height adjustment of the spring member via notches on the fastening rods, the prestressing force can also be varied in accordance with the changing forces in accordance with the lever law.

This spring element not only causes the rod to be held in a certain position and the pretensioning of this rod, but also resets the rod connected to the ball in its starting position when the spring element contracts again, which results in a high exercise frequency on the tennis technique trainer according to the invention .

Wobbling movements, which the rod executes during its rotation, can be prevented by the arrangement of side guide disks on the axis, so that this ensures an optimal rotational movement of the rod. If the axle is separated between these side guide disks, with one axle part being axially displaceable in the other, the braking effect of the tennis technique trainer according to the invention can be improved even more because of the the rod rotary motion generated increasing spring force, so that these lateral guide disks pressing and thus brake this about the mounting rods on the mutually g _l EIT movable axle parts and is thus transmitted to the side guide discs to the rod or its bearing ring. Such an arrangement also has the advantage that the rod is clamped between the side guide disks with a corresponding tension of the spring member and thus there is also a possibility of simulation between soft and hard impacts.

The dependent claims contain advantageous developments of the invention.

Further details, features and advantages of the invention result from the following description of exemplary embodiments with reference to the drawing.

• Fig. 1 schematisch eine Seitenansicht eines erfindungsgemäßen Tennistechniktrainers,
• Fig. 2 einen Schnitt gemäß Linie I-I in Fig. 1 und
• Fig. 3 einen vergrößerten Ausschnitt von Fig. 1, teilweise im Querschnitt.

It shows

• 1 schematically shows a side view of a tennis technique trainer according to the invention,
• Fig. 2 shows a section along line II in Fig. 1 and
• Fig. 3 is an enlarged section of Fig. 1, partially in cross section.

The operation of the tennis technique trainer according to the invention is explained with reference to FIGS. 1 to 3. This tennis technique trainer has a rod 1 which is rotatably mounted on the axis 3. A ball 18, which is usually the size of a tennis ball, is attached to the end of the rod 1 opposite the axis 3. The weight of this ball 18 and the stick 1 should essentially correspond to the weight of a normal tennis ball, so that the player feels as if he were playing a real tennis ball when playing. The rod 1 is over a bearing ring 12 suspended on the axis 1 so that it can swing freely after the stroke, provided there is no braking.

At its free end, the axis 3 can be connected to a conventional fastening element, for example a screw clamp, which in turn is fastened to a solid base. On the other hand, the axle end can also be screwed directly to a wall with the help of a flange or connected to a frame using fastening elements. These fasteners should be such that the axis can be arranged horizontally in a wide variety of angle settings.

According to the invention, the rod 1 is connected to a spring member 2 such that this spring member 2 is tensioned in the event of a rod deflection and has a restoring force on the rod 1. This spring member 2 is aligned essentially parallel to the axis 3 and is at a certain distance from this axis 3. This distance is determined in that the spring member 2 is attached between fastening rods 4, 4 ', which are inserted into the axis 1 at a certain distance from one another. The fastening rods 4, 4 'are either screwed or pressed into the axis or, in an expedient embodiment, they penetrate the axis 1, as shown in FIGS. 1 and 2. According to this embodiment, a further spring member 10 can be provided above the axis, which should have essentially the same spring characteristic and preload as the spring member 2.

The connection of the rod 1 to the spring member 2 is to be understood to mean any arrangement by which the rod 1 is held firmly in any starting position and is returned there after swinging out. So it is both to understand the arrangement of the rod 1 between an endless rubber band 5 stretched on the fastening rods 4, 4 ', as can be seen in particular in FIG. 2, as well as the direct fastening of the rod 1 to a helical spring 6, as shown in FIG Fig. 3 is shown. 1 and 2, the rod 1 is pressed against one half of the endless rubber band 5 when it swings out, which counteracts the movement of the rod 1 and returns it to the starting position between the two parts of the endless rubber band 5.

All springs that can be tensioned in the longitudinal direction can be considered as the spring member 2, preferably one or more endless rubber bands 5 or coil springs 6. In a special embodiment, several spring members 2 with different spring characteristics can be arranged one above the other, so that oscillation of the rod 1 is practically prevented.

If a helical spring 6, as shown in FIG. 3, is used as the spring member 2, this helical spring 6 can have an eye 7 in the middle, through which the rod 1 can be guided. If this helical spring 7 is to be provided with a certain pretension, which is intended to simulate a ball hit harder, this helical spring 6 has on both ends at its ends a plurality of eyes arranged one behind the other, into which the fastening rods 4 can be inserted. This allows the spring force or preload of the coil spring 6 to be varied and prevents the rod 1 from being displaced on the axis 3. On the other hand, it is sufficient that only one end of the helical spring 6 is equipped with these eyes 8 if it has a web in its center which slides through a bore of the rod, so that the rod 1 is also not on the Axis 3 must be moved when the coil spring 6 is under tension. If necessary, this helical spring 6 can also consist of two springs which are connected to one another via this web. On the other hand, the rod 1 can also be connected to the spring member 2 via a fastening element, in particular a ring, wherein this ring can be displaced on the spring member in the rest position of the rod 1.

The spring and restoring force of the spring element 2 exerted on the swinging rod 1 is determined both by the spring characteristic and the prestress of the spring element and by the distance of the spring element 2 from the axis 3. The shorter this distance, the lower the force exerted on the rod 1 according to the lever law. The restoring force of the spring member 2 can thus be varied via the height adjustability on the fastening rods 4, 4 '. For any height adjustment, several notches 9 are therefore provided in a special embodiment on the fastening rods 4, 4 ', via which the spring member 2 can be arranged in the desired height setting. Furthermore, 3 side guide disks 11, 11 'are provided on the axis, which ensure that the rod 1 executes a rotating movement in a certain plane after swinging out. An uncontrolled sequence of movements of the rod 1, which could lead to a collision with the fastening rods 4, 4 ', is thereby excluded. To the encounter metallic parts, for example of the rod 1 and the side guide plates 1 _1, 11 too great noise 'to prevent are discs 13, 13' provided in plastic in each case between the bearing ring 12 of the rod 1 and the side guide wheels 11, 11 ' . On the other hand, the bearing ring 12 can also be provided with a noise-inhibiting layer made of plastic.

If generally every deflection of the rod ₁ to the side is to be prevented, a roller bearing pressed onto the axle 3 can be provided instead of the disks 11, 11 'and 13, 13', on which the bearing ring 12 is fastened. In general, however, the pane design is preferable from a cost point of view.

In a particularly preferred embodiment, the axle 3 consists of two axle parts, the division between the two side guide disks 11, 11 'having been carried out so that the rod can be removed and rotated through 180 °. This allows a player to perform forward and backhand strokes with the same position on the exercise device. The two axle parts are designed such that one axle part can be slid into the other axle part in such a way that the arrangement shown in FIGS. 1 and 2 is obtained. What is important about the axis division is that the distance between the two side guide disks 11, 11 'can be changed, so that these disks or disks 13, 13', under load, of whatever type, bear against rod 1 or its bearing ring 12 and put a certain pressure on them. For example, by prestressing the spring element 2, that is, by selecting a specific spring element with a specific spring characteristic or by tensioning this spring element in the rest position, a stationary pressure can be exerted on the rod 1. This pressure, which is variable as a function of the spring tension selected, gives the player the impression that he is hitting a ball which, owing to its airspeed, strikes its racket with a certain impact pressure. As explained above, this impact pressure can be set by the number of spring members 2 and their pretensioning or spring characteristic.

However, this arrangement has the further advantage that the restoring force of the spring member 2 increases steadily as the rod 1 swings out, so that the pressure exerted on the rod via the movable axle parts or the disks 11, 11 'and 13, 13' also increases. Due to this increasing friction pressure, the rod is braked very quickly and is returned to the starting position by the tensioned spring member 2, so that there is no pinching of the rod 1.

As shown in FIG. 3, the separate axle parts can be pushed into one another, the end 15 of the axle tube which is inserted in the one axle tube having an axially parallel elongated hole 14 which is penetrated by one of the fastening rods 4, 4 '. This axially slidable elongated hole 14 ensures the variability of the spacing of the side guide disks 11, 11 ', so that the above-mentioned pressure exertion is maintained under load. The fastening rod passing through the elongated hole 14 is fixedly arranged in the outer axle tube, for example by screwing in or is prevented from slipping through a stop.

As a rule, the spring member 2 will have to be fastened with a slight pretension between the fastening rods 4, 4 'in order to prevent this spring member from falling or slipping off. This preload means in the choice of the embodiment, which is separated into two axle parts, that a constant pressure is exerted on the rod 1 and the playing of apparently stationary balls, as is made impossible on impact. In a further embodiment, this pressure on the rod 1 can be counteracted by a spiral spring 16 inserted into the one tubular part, which acts on the end 15 of the other axle part. This coil spring is held by a pin in the tubular axle part and can be moved in corresponding recesses of the axle part by moving the pin be changed in its pressure acting on the end 15 such that spring members 2 with different spring characteristics and / or pretension can be used.

The rod 1 is usually made of metal or of a relatively rigid plastic and has in a preferred embodiment, the level of the fixed ball 18 is a crank 19, a crank 90 ^0- is preferred. Expedient has been found that the pendulum is divided in the amount of the offset as shown so that the ball 18 as shown in Fig. 2 by dashed lines, to ₁ ° 80 is pivotable. This eliminates the need to disassemble axis 1.

Due to the rotatability of the axis 3, all complicated techniques can be practiced, since both an inclined position and an upright position of the rod is possible. If the rod is attached to a tripod rod and can therefore be adjusted in height, numerous practice shots can be carried out quickly in a confined space, as is necessary, for example, when teaching larger groups.

Claims (12)

_1st Tennis technique trainer with a rod that is provided with a ball at one end and rotatable at the other end about an axis and between side guide plates and with at least one fastening means that is arranged on the side of a side guide plate and preferably perpendicular to the axis and with a reset device for the Rod, characterized in that the rod ( ₁ ) is connected to a spring member (2) and that at least one spring member (2) is connected to each fastening means (4), which is at different distances from the axis (3) on the rod ( ₁ ) can be arranged. 2. Tennistechniktrainer according to claim 1, characterized in that as a spring member (2) one or more endless rubber bands (5) with possibly different spring properties are used, these being stretched on as fastening rods (4) fasteners so that the rod ( 1) between the individual rubber band parts. 3. tennis technique trainer according to claim 1 or 2, characterized in that one or more coil springs (6) are used as spring element (2) with possibly different spring properties. 4. Tennistechniktrainer according to claim 3, characterized in that the coil springs (6) approximately in the middle have an eye (7) into which the rod (1) can be used. 5. Tennistechniktrainer according to one of claims ₁ to 4, characterized by spring members (2), which have at their ends a plurality of eyes arranged one behind the other (8), into which the fastening rods (4) can be inserted and via which the spring force is adjustable. 6. tennis technique trainer according to one of the preceding claims ₁ to 5, characterized in that the rod (1) is connected via a fastening element, in particular a ring with the spring member (2). 7. tennis technique trainer according to one of claims ₁ to 6, characterized in that the axis (3) consists of two axle parts, one of which is slidably mounted in the other and each have a side guide plate (11, 11 '), with a deflection of the rod ( ₁ ) via the increasing tension of the spring element (2), the pressure exerted on the bearing ring ( ₁ 2) of the rod (1) via the side guide disc (11, 11 ') and possibly the discs (13, 13') increases. 8. tennis technique trainer according to one of the preceding claims 1 to 7, characterized in that the fastening rods (4) pass through the axis (3) and mirror image on the other side also a spring member, preferably with the same spring characteristic and the same preload, can be attached. 9. Tennistechniktrainer according to claim 7, characterized in that in the one axle tube stuck another axle tube has an axially parallel elongated hole (14) which is penetrated by the fastening rod (4,4 ') firmly connected to the outer axle tube in such a way that the one Axle tube on the other axle tube is axially displaceable. 10. Tennistechniktrainer according to claim 7 or 9, characterized in that in the one axle tube stuck end ( ₁₅ ) of the inner axle part by a helical compression spring (16) can be acted upon by a pin (17) penetrating the axis (3) in the Axis (3) is arranged axially displaceable. 1 ₁ . Tennis technique trainer according to one of the preceding claims ₁ to ₁ 0, characterized in that a bearing ring ( ₁ 2) of the rod ( ₁ ) sits firmly on a roller bearing. ₁ 2. Tennistechniktrainer according to one of the preceding claims 1 to 1 ₁ , characterized in that the rod ( ₁ ) consists of metal or plastic and at the level of the attached ball (18) a crank (19) -preferably a 90 ^o- cranking- and that the lower part of the rod (1) can be pivoted through 180 ° in the counter-cranking direction.

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