EP3169413A1

EP3169413A1 - Tennis training device

Info

Publication number: EP3169413A1
Application number: EP15735677.5A
Authority: EP
Inventors: Josef Dagn
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-07-17
Filing date: 2015-07-07
Publication date: 2017-05-24
Anticipated expiration: 2035-07-07
Also published as: CN106999759A; PL3169413T3; EP3169413B1; US20170203183A1; CN106999759B; ES2699087T3; JP6571769B2; JP2017521217A; WO2016008767A1; US10065099B2; DE202014103293U1

Abstract

The invention relates to a tennis training device comprising a supporting bar (5) that is hinged to a base (B, 6), can be pivoted between a first stop (8) and a second stop (9), and pivotably supports a profiled rod (3) which projects from the support bar (5) and at the free end of which a ball (1) is rotatably mounted; the second stop (9) in the hitting direction is supported so as to be pivotable against a force.

Description

Tennis training device

The invention relates to a tennis training device

DE 20 2011 107 013 describes a tennis training device that is designed in particular for practicing slice and topspin punches, It is provided a link which is pivotable against spring force and articulated on a horizontally movable carriage, wherein one at the free end of the Handlebar mounted bracket rotatably holds the ball and the carriage is slidable in a longitudinal guide against spring force,

The invention has for its object to develop a tennis training device of this kind so that essentially all types of punches including forehand and backhand shots can be practiced,

According to the invention a ball is rotatably mounted at the free end of a profiled bar, which is pivotable on a carrier rod pivotable between a first and second stop, wherein the lying in the direction of impact second stop is resiliently supported against a force.

The tennis training device according to the invention comprises a hinged to a base support rod which is pivotable between a first and a second stop and a pivotally projecting from the support rod profile rod carries at its free end a ball is rotatably mounted, wherein the second stop in the direction of impact against a force is supported pivotably, for example against a spring force, so that a deflection of the voltage applied to the second stop support rod in the direction of impact is possible, which is slowed down by the opposing force, For example, the second stop can be pivotally supported in the direction of impact by an adjustable counterweight, which is moved by a pivoting movement of the second stop, is preferably pivoted,

According to a further embodiment, the force acting on the second stop can be formed by a rotatable counterweight which is mounted on the circumference of a disc, which is connected via a cable to the stop,

Here, the force of the rotatable counterweight can be influenced by a curve on the disc, along which the cable runs.

According to a further advantageous embodiment, the support rod between two bearing blocks forming a plate can be mounted pivotably. The bearing block is preferably mounted on a base plate which is pivotable about an upright pivot axis by an adjusting device relative to a stationary structure and can be fixed in the pivoting position

Advantageously, the base plate is pivotable on a pivotable plate in a small angular range, wherein at a distance from each other arranged magnets allow a swinging of the bearing block between the magnets

The profile bar is advantageously designed to be longer than the support rod and it is pivotable between stops on the support rod, so that the profile bar already makes a deflection in the direction of impact after a blow to the ball before the support rod is pivoted.

So that the profile bar is not touched when swinging the tennis racket of this, the profile bar is advantageously curved,

The pivotable mounting of the profile bar on the support rod is advantageously along the support rod adjustable, for example by an adjustable on the support rod sleeve, which can be firmly connected in the respective position with the support rod The training device can be arranged in a stationary manner. The device is preferably arranged in a housing which is height-adjustable via a linkage on a chassis, wherein the chassis can be locked on the ground,

Various sensors and an electronic memory device can be provided by which parameters of the ball movement are recorded and stored so that the ball movement can be reproduced after a hit with the tennis racket on the ball on a monitor.

Advantageously, the ball is rotatably mounted with different colors on the ball circumference at the free end of the profile bar, so that based on the different coloring of the ball, the direction of rotation after a strike is visually easily recognizable

Advantageously, the ball is formed by two half-shells, which are preferably made of foamed material, e.g. Polyurethane foam exist.

For example, embodiments of the invention will be explained in more detail with reference to the drawing, show it

Fig. 1 shows a preferred first embodiment in a side view in one

Starting position

1 in a side view in the starting position without support of the second stop,

Fig. 3 shows an intermediate position in the illustration of FIG. 2 after executing a

shock,

4, the end position after execution of a blow in the representation of

2 and 3,

5 shows a side view of the first embodiment according to FIG. 1, showing the application of the second stop, FIG.

6 in the illustration of FIG. 5 the end position of FIG. 4, FIG.

Fig. 7 is a plan view of the base plate, wherein

7a shows the view of FIGS. 2 to 4 and FIG

FIG. 7b shows the view of FIG. 1 and of FIGS. 5 and 6, FIG. Fig. 8 is a side view of the movable on a chassis training device, wherein

Fig. 8a a raised position and

Fig. 8b shows a lowered position,

9 is a schematic representation of the storage of the ball,

10 is a schematic side view of a second embodiment of the

Device at rest,

11-13 intermediate positions of the device in the view of FIG. 10 after performing a strike,

14 is a view of a third embodiment of the device,

Fig 5-16 intermediate positions of the device,

17 is a schematic side view of the housing with cover,

Figure 18 is a plan view of the housing in the region of the support rod, and Figure 19 shows schematically the connection of the base plate with a stationary structure

In Fig. 1, 1 denotes a ball which is rotatably supported at 2 preferably by a ball bearing at the end of a curved in the direction of impact profile bar 3, for example, an aluminum rectangular tube with a rotation axis perpendicular to the plane of the profile bar 3 is rigid and be opposite end is pivotally mounted at 4 at the upper end portion of a support rod 5, which consists for example of an aluminum rectangular tube,

The curvature of the profile bar 3 is designed so that when a slice hit the racket can swing freely after hitting the ball and is not hindered by the pivoted profile bar 3 (Figures 3 and 4).

9 schematically shows the mounting of a ball 1 constructed from two half-shells 1a and 1b whose outer surface is preferably of two-color design, so that the rotational movement of the ball is clearly recognizable after a topspin or slice strike.

The two half-shells 1a and 1b of the ball are preferably made of foamed material, eg. Polyurethane foam, each half-shell between a Holding disk 1 .1 and a flange 1 2 is held on a shaft 1, 3, as shown in FIG. 9a. The shaft 1.3 is formed in two parts, wherein a reduced diameter portion engages in a sleeve-shaped part 1, 31, as shown in FIG 9a and 9b can be seen, the two retaining disks 1, 1 are fastened by screws to the shaft and the two fixedly interconnected half-shells are supported by a ball bearing 2, which is arranged on the reduced diameter portion of the shaft 1, 3.

The pivotable mounting 4 of the Profiistabes 3 may be formed on a sleeve 4.1 (Figure 10), which is adjustable along the support rod 5, wherein the sleeve is 4.1 in the respective position fixed to the support rod 5,

In the region of the articulation point 4 of the profile bar 3 on the support rod 5 stops are provided suitably, between which the profile bar 3 is pivotable relative to the support rod 5, wherein the stops are suitably provided with an elastomer coating or with a damping pad,

1 shows an upper damper 4a with an elastomer cushion, which is firmly connected to the support rod 5. Furthermore, a lower damper 4b is firmly connected to the support rod 5, on which the profile rod 3 rests in the rest position shown in FIG.

Also, a spring action can be provided, which counteracts a pivoting movement of the Profiistabes 3 from the position of Fig. 1 in the position of the Fig, 4 and the profile bar 3 from the pivot position in Fig, 4 back to the starting position of FIG

In particular, a leaf spring can be provided on the bearing 4, which acts on the pivoting movement of the Profiistabes 3 to ensure an elastic impact of the racket on the ball 1.

Figures 2 to 4 show the basic structure of the articulation of the support rod 5 on a base plate 100, wherein Figure 2 corresponds to the starting position in Fig, 1. The support rod 5 is pivotally mounted at 7 at the lower end in or on a bearing block 6 The bearing block 6 may consist of two in cross-section L-shaped aluminum plates, wherein the shorter legs are attached to the base plate 100 The pivotal movement of the support rod 5 against the direction of impact is limited by a first stop 8. In the starting position of FIGS. 1 and 2, the carrier bar 5 lies with its lower end against the first stop 8, which in the exemplary embodiment of FIGS. 1 to 4 is designed as a gas pressure spring

Instead of a gas spring 8 may also be another stop preferably provided with a damping effect, as shown in the other embodiments, which are described below.

The support bar 5 hits after a blow with the tennis racket on the ball 1 in Fig. 3 in its pivotal movement in the clockwise direction about the pivot point 7 on a second stop 9, which is pivotally mounted in the first embodiment on the bearing block 6 at 9 2. The second stop 9 is formed by a strut 9 1 with an elastomeric pad 9.3 at the free end, on which the support rod 5 impinges during its pivoting movement,

The second stop 9 is resiliently supported with a counter force, as described below with reference to FIG. 5 and 6 will be explained in more detail.

After installation of the support rod 5 on the second stop 9 in the intermediate position of Fig. 3 comes in the further pivotal movement of the support rod 5 in the clockwise direction, the elastic support of the second stop 9 to the effect

Fig. 4 shows the end position of the pivoting movement of the carrier bar 5 after a strike has been made on the ball 1, the second stop 9 resting on a third stop 10, which is fixedly arranged on the base plate 100 and provided with a damping pad 10a. In this end position of FIG 4, the carrier bar 5 is cushioned in two respects, once by the cushioning pad 9, 3 and the damping pad 10 a on the third stopper 10.

The free swinging of the ball 1 from the starting position in FIGS. 1 and 2 until the impact of the carrier bar 5 on the second stop 9 forms a kind of idling area. because the impact on the ball 1 has essentially only to overcome the weight of the ball 1 to force, this idle range until impact on the second stop 9 favors so little resistance on the ball 1 upon impact of the racket.

Fig. 3 shows the system of the support rod 5 on the second stop 9, after a blow was carried out on the ball 1, on a first section, the support rod 5 moves substantially freely between the two stops 8 and 9. Only when conditioning the support rod. 5 At the second stop 9, after contact between the ball 1 and tennis racket no longer exists, the support rod 5 is further pivoted against the action of force by the force of the executed blow, In Fig. 2, the second stop 9 is still in the starting position of FIG. 1.

The second stop 9 can be supported by a linkage or a link mechanism acting on a counterweight 11 and transmits the pivotal movement of the second stop 9 on this counterweight 11, for example by leverage, as shown in FIGS. 10 and 14 show.

Preferably, the damping stop 9 is acted upon by a rotatably mounted counterweight 11, which is mounted in Figure 1 on a disc 12, which is connected via a cable 13, preferably a plastic sheathed wire, with the free end of the damping stop 9 to the stop 9 from the end position in FIGS. 4 and 6 to the position in FIGS. 2 and 5,

On both sides of the bearing block 6, a disc 12 is preferably rotatably supported preferably made of aluminum, on the circumference of the counterweight 11 is applied from the circumference of the two discs 12, the cable 13 leads to the upper end of the damping stop 9, so when pivoting the damping stop 9 by the support rod. 5 the disks 12 are rotated in a clockwise direction in FIGS. 5 and 6, in this case the counterweight 11 acts to damp the pivoting movement of the support rod 5 as soon as the damping abutment 9 is pivoted by the support rod 5, For a gentle cushioning of the damping stop 9, the cable 13 is guided on the two discs 12 along a curve, in particular along a helically shaped recess 12a through which the rotational movement of the disc 12 with counterweight 11 during the initial pivoting of the damping stop 9 only slowly and then always stronger, the farther the damping stop 9 is pivoted clockwise

From the Endsteilung in Fig, 4 and 6, the device is automatically moved back to the starting position of Figures 1, 2 and 5 by the applied on the discs 12 counterweight 1, the discs 12 rotates counterclockwise and thus the damping stop 9 by means of the rope When the carrier bar 5 is in a position corresponding to FIG. 3, in which the damping stop 9 is no longer pivoted counterclockwise, the weight of the profile bar 3 projecting from the carrier bar 5 acts on the support rod 5 in such a way that it moves further counterclockwise to the starting position of FIGS. 5 and 2, the lower end of the support rod 5 coming into contact with the preferably spring-sprung stop 8, in particular in the form of the gas spring, and being decelerated.

In this embodiment, the gas spring 8 is used to ensure that the retrieval of the ball 1 runs at a uniform speed and the ball 1 is again quietly in the starting position of FIG. 1,

Preferably, a stop 11 a is provided for the counterweight 1 in the end position, which is shown in Fig. 1 on the base plate 100.

Fig. 7a shows a top view of the base plate 100 with bearing block 6, the discs 12 with counterweight 11 being omitted for clearer reproduction, FIG. 7b shows a plan view of the base plate 100 according to FIGS. 1 and 5 with counterweight 11 and discs 12. As shown in FIG. 7a, the bearing block 6 is formed of two L-profiles 6 1 and 6. 2 arranged parallel to one another, preferably of aluminum, between which the support rod 5 can be pivoted on a bearing pin 7

The bearing block 6 is mounted on the base plate 100, which is relative to a stationary structure 200 pivotable about a in Fig. 1 at 100a indicated storage in the plane of Fig. 7a to the right and left, which in the illustrated embodiment, the housing explained in more detail below 200 is on a chassis. In Fig, 7a is perpendicular to the plane lying pivot axis 100a of the base plate 100 in the region of the support rod 5, as shown in FIG 1 can be seen. At the front end of the base plate 100, a projection 100.1 made of ferromagnetic material is provided, which lies in the rest position between two magnets 102 at a distance from these. The two magnets 102 are arranged on a plate 100 ', on which the base plate 100 in a certain Area is arranged laterally movable or pivotable, so that the base plate 100 in a certain range relative to the plate 100 'can vibrate horizontally and vibrate when the ball 1 is hit on the profile bar 3 slightly laterally to the pivot plane of the support rod 5 and thus a lateral force is introduced into the bearing block 6. After a lateral deflection of the base plate 100 relative to the plate 100 ', the base plate 100 is brought by the magnets 102 back into the reproduced in Fig 7a center position,

On the stationary structure 200, a handwheel 300 is rotatable, about which a toothed belt 301 is guided, which is guided over deflection rollers 302 and connected to the ends of the in FIG. 7a is attached to the upper end of the plate 100 'at 303,

By turning the hand wheel 300, an inclination of the plate 100 'and thus the base plate 100 can be adjusted. At 304, a detent is provided on the circumference of the handwheel 300 to allow the handwheel 300 to be fixed in a designated swivel pitch,

By a double arrow P is in Fig. 7a indicates that the plate 100 "can be pivoted with the base plate 100 in both pivoting directions relative to the stationary structure 200, Fig. 7b shows the same view as Fig. 7a, but with the discs 12 are shown with counterweight 11, the counterweight 11 connects in this embodiment, the two discs 12, so that they form a unit, via the wire ropes 13 with the second stop. 9 is connected, which is not shown in Fig. 7b.

Fig. 8 shows a side view of a device in which the training device is mounted on a height-adjustable chassis.

The training device with base plate 100 is mounted on the bottom plate 200 of a box-shaped housing 200 a, which is articulated via two links 201 a and 201 b with a chassis 202, to the lockable wheels 202.1 and attached to a strut 202,2 handle for moving Between the steering 201a and the front portion of the chassis 202, a gas spring 203 is mounted, which supports the pivoting action of the housing 200a relative to the chassis 202. 204 denotes a strut between the handlebar 201a and the chassis 202, by means of which the respective Height position of the housing 200a relative to the chassis 202 can be fixed at 204a,

8b shows a lowered position of the training device and FIG. 8a shows a raised position, FIG.

The described training device can be provided with electrical sensors and software, can be registered by the details or parameters of a blow on the ball 1 and displayed for example on a monitor with printer and printed.

To determine the individual parameters of a blow with the tennis racket on the ball 1, the articulation of the base plate 100 on the plate 100 'and the Vibrierbewegung the base plate 100 between the magnet 102 is used

It can also be provided a scanner, by means of which the number of strokes can be registered, which then passed on to the electronics and processed becomes

In the chassis 202, for example, a battery for the electrical power supply of the electronic components may be provided and an electric motor for driving the height adjustment of the frame.

10 shows a schematic side view of a second embodiment, in which the second stop 9 is supported via a link arrangement 17 by a counterweight 11 which is displaceable on a roller 15

For ease of illustration, the pivotal movement of the profile bar 3 limiting stops are omitted at the pivot point of the profile bar 3 on the support rod 5,.

The same or corresponding components are provided with the same reference numerals as in FIG. 1 to 9,

FIGS. 11 to 13 correspond to FIGS. 3 and 4 of the first embodiment with regard to the relative position of the individual parts of the device.

In this embodiment, the stops 8 and 9 are formed as rollers, which may consist of an elastomeric material, wherein the second stopper 9 acts via a link mechanism 17, 17 a against a counterweight 11 which rests on the roller 15. The link mechanism has an acute-angled lever 17, which is articulated at one end at 17 1 on the bearing block 6 or, on the base and is pivotally connected to the opposite end at 17.2 with one end of the elongated counterweight 11. The angled portion 17.3 of the lever 17 serves as a support on the base B in the rest position

This embodiment can also be positioned in height-adjustable manner on a frame 200, 202.

Fig. 14 schematically shows a third embodiment Denoted by 20 is a bearing B fixed to the base, at the free end of which a double-armed lever 21 is pivotably mounted approximately in the middle at 21.1 (FIG. 15)

The left end of the double-armed lever 21 is articulated at 21 2 with a handlebar 24 which is hinged to the second stop 9 at 24.1 The opposite end of the double-armed lever 21 is at 21, 3 with a preferably rod-shaped counterweight 1, for example, a metal cylinder , articulated, which rests on a roller 15, preferably a rubber roller, which is rotatably mounted via a bearing at 15, 1 on the base B.

In the initial position of Fig. 14 of the double-armed lever 21 is slightly obliquely relative to the longitudinal axis of the counterweight 11 and the longitudinal axis of the link 14, so after further pivotal movement of the support rod 5 in the clockwise direction in Flg .. 15, the left end of the double-armed lever 21 by the handlebar 14 is pressed down and the right end of the lever 21 is pivoted upwardly, said end of the lever 21 pulls the counterweight 11 while rolling on the roller 15 upwards.

16 shows a possible end position of the ball 1 after a strong impact, the lever 21 is pivoted counterclockwise and the counterweight 11 is raised relatively far, so that the lower end portion of the rod-shaped counterweight 11 rests on the roller 15,

The evasive movement of the profile bar 3 in conjunction with the curved shape, as shown in Fig. 16 reproduced, mainly serves to allow a space for the club swing after performing a slice hit

From the end position in Fig. 16, the device is automatically moved back to the starting position of FIG. 14, wherein the resting on the roller 5 counterweight 11 by gravity effect of the roller 15 projecting portion which pulls the counterweight 11 down, the two-armed lever 21 pivoted clockwise while the counterweight 1 rolls on the roller 15 to the right, so that the left end of the lever 21 via the handlebar 4, the second Stop 9 and with this the carrier bar 5 in the position of Fig. 15 is pushed back. After reaching the position in FIG. 15 solves the carrier bar 5 by the weight of the profile bar 3 and the ball 1 from the second stop 9 and tilts back into the position of Fig. 14, in which it rests against the first stop 8, preferably with a slight tilt to the left

In this pivotal movement of the support rod 5 in the counterclockwise direction from the end position in Fig. 16 in the starting position in Fig. 14 and the profile bar 3 at the bearing 4 is due to its weight again from the stretched in Figure 16 position relative to the support rod 5 in the position of Fig. 14 moves back, in which the profile bar 3 is approximately at an angle of 100 to 120 ° to the support rod 5,

Fig. 14 shows on the base B an abutment 16 for the counterweight 11, which abuts in the initial position on a damping 16 1 with the free end, wherein the counterweight 11 is held by the roller 15 in an inclined position to the lever 21.

Instead of a damper 8.1 in FIG. 15, a hydraulic damper 8a (FIG. 14) can also be attached to the bearing block 6, which forms the first stop and returns the carrier rod 5 with the ball 1 without springing back into the starting position, when the carrier rod 5 moves backwards Applying force to the second movable stop 9,

Fig. 17 shows schematically a side view of the training device of the first embodiment with a housing according to Fig, 8, wherein above the base plate 100, a cover 200 b is provided which protects the structure on the base plate 100 against dust and dirt, especially after the initial phase of Shock on the ball 1, the pivoting of the support rod 5 should be possible frictionless and without resistance,

The handwheel 300 is arranged on the closed hood 200b, as the plan view in FIG. 18 shows, by means of which the base plate 100 is connected to the carrier bar 5. FIG. 18 shows a pivoting to the left and a pivoting to the right relative to the housing 200, FIG.

After the support rod 5 is pivotable in the direction of impact of the ball 1 and is pivoted laterally relative to the housing, as shown in FIG. 8, a plastic plate 400 is movably mounted on the hood 200 b, which has a metal frame 401 with a central longitudinal slot 402, along which the Carrier rod 5 is movable,

In order to protect the slot 402 against the ingress of dust and dirt, a brush cover 403 is preferably made of glass fibers, through which the movement of the support rod 5 along the slot 402 as little as possible obstructed, The glass fibers extend from both sides of the slot 402 provided bars 404th approximately to the middle of the slot, so that the support rod 5 can move without appreciable resistance along the slot 402.

19 schematically shows the articulation of the device on the bottom plate 200 of the housing in FIG. 8 with the pivot axis indicated in FIG. 1 at 100a, FIG.

In a bore of the bottom plate 200, a hinge pin 500 is rotatably inserted, on which a nut 501 and a lock nut 502 are screwed. Between nut 501 and bottom plate 200, a Teflon disk 503 is provided, by which the friction between bottom plate 200 and nut 501 is kept low,

The Geienkbolzen 500 is rotationally fixed in a bore of the plate 100 'is pressed, which is pivotable about the axis of the hinge pin 500 by the handwheel 300 and the toothed belt 301 relative to the bottom plate 200

Between bottom plate 200 and plate 100 'is a plastic plate 504 used to reduce friction

Over the plate 100 ', the base plate 100 of the device is pivotally mounted on the hinge pin 500 so that the base plate 100 is pivotable relative to the plate 100' between the magnets 102 on the plate 100 ',

At 505, another plastic plate is provided between the base plate 100 and the friction reduction plate 100 ' By turning the handwheel 300, the plate 100 'can be pivoted relative to the bottom plate 200 of the housing, wherein the base plate 00, on which the bearing block 6 is fixed, taken by their approach 100.1 between the mounted on the plate 100' magnet 102 in the pivot position becomes .

The exercise device described can be used as a home trainer in the basement or in a garage, but also serve as a support for a tennis teacher, the device can be used in particular for practicing topspin, lobes and sice ski. The ball rotation is at topspin and slice Blows visually reproduced by the color change on the ball Also, an electronic speed measurement on the ball is possible, on a display, not shown, the speed of the ball can be displayed.

Since the ball 1 is always positioned in the starting position in the same position, the club swing can be automated,

There are various modifications of the construction described possible. Thus, instead of the counterweight 11, a spring construction can be provided which resiliently supports the second stop 9 via the link mechanism 10 or 10a.

Claims

claims

Tennis training device, comprising

a carrier rod (5) hinged to a base (B, 6), which is pivotable between a first (8) and a second stop (9) and pivotably carries a profiled bar (3) protruding from the carrier bar (5), at the free end thereof End of a ball (1) is rotatably mounted,

wherein the second direction in the direction of impact stop (9) is pivotally supported against a force.

Apparatus according to claim 1, wherein the impact direction in the second stop (9) by an adjustable counterweight (11) is pivotally supported, which by a pivoting movement of the second stop (9) is movable, preferably pivotable.

Apparatus according to claim 1 or 2, wherein the profiled bar (3) is pivotably articulated between preferably elastically yielding stops on the carrier bar (5)

Device according to one of the preceding claims, wherein the pivotable mounting of the profiled bar (3) along the support rod (5) is adjustable.

Device according to one of the preceding claims, wherein the profile bar (3) is curved.

Device according to one of the preceding claims, wherein the profile bar (3) is designed to be longer than the carrier bar (5), Device according to one of the preceding claims, wherein the second stop (9) is supported by a rotatable counterweight (11) mounted on the periphery of a disc (12) connected to the stop (9) by a cable (13) is

Device according to one of the preceding claims, wherein the support rod (5) is pivotably mounted in the direction of impact between two plates (6, 1, 6, 2) forming a bearing block (6),

Apparatus according to claim 8, wherein the bearing block (6) is mounted on a base plate (100) which is pivotable relative to a stationary structure (200) about a vertical pivot axis (100a) and fixable in the pivot position by an adjusting device (300).

Apparatus according to claim 9, wherein the base plate (100) is pivotally mounted on a pivotable plate (100 ') in a small angular range on which magnets (102) are mounted at a distance from one another, between which the bearing block (6) can oscillate.

Device according to one of the preceding claims, wherein the device in a housing (200) is arranged, which is height adjustable via a linkage on a chassis

Apparatus according to any one of the preceding claims, wherein sensors and an electronic memory device are provided by which parameters of the ball movement are recorded and stored.

Device according to one of the preceding claims, wherein the pivoting movement of the second stop (9) is limited in the sliding direction by a stop (10),

4. Device according to one of the preceding claims, wherein the return movement of the rotatable counterweight (11) by a stop (11 a) is limited 5, device according to one of the preceding claims, wherein the first stop (8) is formed by a gas spring