Tennis training device

A tennis training device is provided, comprising a support bar which is swivelable between a first and a second stop in its longitudinal direction, wherein at the free end of the support bar a ball is mounted by means of a connecting ember, which is releasably fixed by means of a fixing means.Furthermore, the invention relates to different embodiments of a training unit.

The invention relates to a tennis training device anti especially to a holding device of a ball on a support bar.

WO 2016/008767 describes a tennis training device in which a ball is rotatably mounted at the free end of a section rod which is connected swivelably in the longitudinal direction to a support bar, which in turn is swivelably mounted at a base. Hereby, the section rod forms an elongation of the support bar.

The invention is based on the object of designing the mounting of the ball at a tennis training device such that different game situations can be trained better.

This is achieved according to the invention, in that the ball is mountable in an exchangeable manner and having different holding means at the tennis training device, so that different stroke techniques can be trained.

According to the invention, for a tennis training device in which a support bar supporting the ball is articulatedly mounted at a base and swivelable between a first and a second stop, at the free end of the support bar the ball is mounted at a connecting member which is releasably connectable to the end of the support bar by means of a fixing means.

In this way, according to playing technique, the ball can be exchanged at the support bar and, by means of different designs of the connecting member, is mounted at the support bar in suitable positions relative to the support bar.

Preferably an elastic extension is mounted at the ball, through which the ball is fixed movably in different directions at the connecting member, by means of which, during the stroke of a tennis racket against the ball, the ball can move in different directions.

Advantageously a preferably curved plate is mounted at the connecting member, at which plate the ball can be supported on a larger surface after the stroke by a tennis racket.

According to an advantageous embodiment, a tension element is mounted at the ball or at the radially protruding elastic extension, which tension element can be formed, for example, in the shape of a hook, which can be hooked onto the support bar in spaced openings. The tension element can be connected to the ball by a rubber band in order to keep the ball under tension in its initial position at the connecting member.

Hereby, the hook and the rubber band or the flexible extension extend through an opening in the curved plate which is provided for supporting the ball.

Preferably the connecting member is inserted into a hollow section rod which is connected to the support bar so that on the one hand, the exchanging is facilitated and on the other hand, a stable mounting of the ball is guaranteed by means of the connecting member.

According to an advantageous embodiment, the connecting member is fixable by means of screws to the hollow section rod, wherein the shaft of the screws engages a longitudinal slot of the section rod. In this way, the screws at the section rod can be fixedly clamped in a simple manner.

According to a further embodiment, the connecting member is formed twisted or wound in its longitudinal direction, so that when the ball is rotatably mounted, the rotational axis of the ball takes up an angle to the longitudinal direction of the support bar. In this way, special stroke techniques with a tennis racket can be practiced better.

FIG. 1shows an embodiment of a tennis training device in a lateral view, wherein a ball1is rotatably supported at2, preferably by a ball bearing at the end of a section rod3, for example an aluminum rectangular tube curved contrary to the direction of stroke, having a rotational axis perpendicular to the plane of the drawing. The section rod3is rigid and in practice it is formed longer than shown. Its opposite end is swivelably supported, preferably by means of ball bearings, at4at the upper end portion of a support bar5which is short in relation to the section rod.

The curve of the section rod3protruding from the support bar5is designed such that for example when carrying out a slice stroke, after hitting the ball the racket can freely follow through and is not hindered by the swiveled section rod (FIGS. 2 and 3).

The swivelable mounting support4of the section rod3can be formed at a sleeve4.1, which is displaceable along the support bar5, wherein the sleeve4.1is fixedly connected with the support bar5. In this way, the section rod3forms an extension of the support bar5.

Stops are provided in the area of the place of articulation4of the section rod3at the support bar5, and between these stops the section rod3is swivelable relative to the support bar5, wherein the stops are advantageously provided with an elastomeric coating and with a damping pad.

FIG. 1shows an upper damper4ahaving an elastomeric pad which is fixedly connected with the support bar5. Further, a lower damper4bis fixedly connected with the support bar5, and the section rod3abuts at this lower damper in the resting position represented inFIG. 1.

Also, a spring action can be provided, which counteracts a swiveling movement of the section rod3out of the position ofFIG. 1into the position ofFIG. 3and which displaces the section rod3out of the swivel position inFIG. 3back into the initial position ofFIG. 1.

In particular, a leaf spring can also be provided at the mounting support4, which acts on the swivel movement of the section rod3to guarantee an elastic striking action of the racket on the ball1.

FIGS. 1 to 3show the basic structure of the articulation of the support bar5at a base plate100.

The support bar5is swivelably supported at7at the lower end in or at a bearing block6. The bearing block6can consist of two metal plates having an L-shaped cross-section, wherein the shorter legs of the metal plates are fixed at the base plate100. The swivel movement of the support bar5in the direction of stroke is limited by a first stop8. In the initial position ofFIG. 1, the support bar5abuts with its lower end at the first stop8, which is formed as a gas pressure spring in the embodiment ofFIGS. 1 to 3.

Instead of a gas pressure spring8, another stop can also be provided, preferably having a damping effect, as represented in the further embodiments which are described in the following.

InFIG. 2, after a stroke on the ball with the tennis racket, the support bar5strikes a second stop9when carrying out its swiveling movement in clockwise direction around the articulation point7. In this embodiment, stop9is swivelably supported at the bearing block6at9.2. The second stop9is formed by a strut9.1having an elastomeric pad9.3at the free end thereof, which the support bar5strikes when carrying out its swiveling movement. InFIGS. 1 to 3, the second stop9is supported in an elastically resilient way in the direction of stroke to the right, for example by an elastic pad which, in this embodiment, is mounted at a bracket10bwhich is fixedly connected with the base plate100and can be elastically supported at10con the base plate100.

Preferably, the second stop9is supported in an elastically resilient way by means of a construction represented inFIG. 4, in which a preferably rotatable pin6ahaving a transverse bore is mounted at the bearing block6on both sides. A rope6bis guided through the transverse bore and fixed at one end to the support bar9.1of the stop9, and on the other side of the pin6athis rope supports a buffer6cat the end in a freely moveable manner. During the swiveling movement of the second stop9, the buffer6ccomes to abut at the pin6aand damps the swiveling movement of the second stop9.

After the support bar5has come to abut at the second stop9in the position inFIG. 3, the elastic support of the second stop9comes into effect during the follow-through swiveling movement of the support bar5in clockwise direction.

In the end position ofFIG. 3, the support bar5is damped in two ways, first, by the damper pad9.3and the resilient support by means of the buffer6c, and second, by means of the damping pad10a, which forms a third stop10.

The buffers6care designed in relation to the pins6asuch that they preferably come into effect approximately at the same time with the striking of the holding plate9.1on the damping pad10a.

Preferably, the effect of the buffers6cand the length of the ropes6bis adjustable.

Also, springs can be provided at the rope of the buffers6cfor further damping.

The free oscillation of the ball1out of the initial position inFIG. 1until striking the support bar5at the second stop9inFIG. 2forms a kind of idling range, because the stroke on the ball1substantially only has to overcome the ball's own weight. In practice, the section rod3protrudes relatively steeply from the support bar5, so the weight of the section rod does not increase the resistance during the striking of the racket on the ball. Thus this idling range until striking the second stop9favors a slight resistance at the ball1when the racket strikes.

InFIG. 3, the device moves itself, or is supported to move out, of the end position by means of a tension spring, back into the initial position ofFIG. 1. As soon as the support bar5is in a position corresponding toFIG. 2, in which the damping stop9is no longer swiveled further in anti-clockwise direction, the weight of the section rod3protruding from the support bar5and of the ball1acts on the support bar5such that it moves further back in anti-clockwise direction into the initial position ofFIG. 1, wherein the lower end of the support bar5comes to abut at the preferably damped stop8and is decelerated.

In this embodiment the gas pressure damper8serves to make sure that the return of the ball1takes place at an even speed and the ball1returns smoothly into the initial position ofFIG. 1. However, the stop8can also be formed in another manner, for example by a rubber buffer.

To decelerate the support bar5when carrying out a forceful stroke, additionally a damper88is provided, which inFIG. 2abuts at the support bar5and decelerates it when swiveling in the direction of stroke, after the ball has already moved away from the racket.

Like all the other dampers and springs, this damper can also be adjustable with regard to damping effect.

FIG. 5shows a perspective view of a holding device of the ball1in the form of a connecting member20, which is exchangeably mounted at the end of the section rod3, so that different types of balls can be fixed at the section rod3or a worn-out ball can be exchanged. For a rotatable ball1supported at a rotational axis2, the connecting member20substantially has a rectangular piece20.1, which is inserted into the rectangular hollow profile of the section rod3. At the connecting member20.1fixed at the bearing of the ball, winged screws or knurled screws20.2are mounted on both sides, whose shafts engage guide grooves3.1at the end of the section rod3.

FIG. 6shows another embodiment of a holding device of the ball. An extension1aof elastic material, such as rubber, is adhered or vulcanized onto the ball1and protrudes radially from the ball and is provided at the end with a hook member22, which can be hung in openings3.2provided spaced apart at the end of the section rod, to keep abutting of the ball under tension at the connecting member20. Advantageously, a plate20.3is provided at the connecting member, on which plate the ball1is supported during a stroke. This plate can be curved in a concave manner on the side facing the ball1.

While for the embodiment according toFIG. 5preferably a less hard ball is used corresponding to a usual tennis ball having a relatively thin rubber layer, in the embodiment ofFIG. 6a ball having a thicker rubber layer of approximately 6 mm is used, as is also used for ball-throwing machines. This ball is harder and suitable for very forceful strokes.

FIG. 6shows a modified embodiment, in which an extension20.31, curved in the circumferential direction of the ball, of the supporting plate20.3is mounted at the connecting member20, and additionally supports the ball in the case of forceful strokes. Hereby, a pressure spring20.32can be provided between ball and extension20.31, in order to support the ball resiliently against the extension of the plate20.3of the connecting member20.

The advantage of mounting the ball according toFIGS. 6 and 6alies in that the ball can move laterally due to the elastic extension1a. This mounting of the ball according toFIGS. 6 and 6ais suitable above all for professional players who carry out forceful strokes, like in a tournament, while the rotatable support according toFIG. 5is very suitable for perfecting a stroke during training.

In the case of the mounting of the ball according toFIGS. 6 and 6a, an impact sensor can be provided between ball1and plate20.3of the connecting member20.

FIG. 7schematically shows a training unit provided with a covering hood102corresponding toFIG. 1, at the base plate100of which, for example quick-release fasteners or tension clamps101are mounted, by means of which the training unit can be fixed at a stable chassis200. InFIG. 7, a movable chassis is indicated, which can be embodied relatively heavy, wherein the rollers200.1are provided with a blocking means so that a stable base for the training unit is obtained.

FIG. 8schematically shows a combined training device in which a rod200ais fixed on the right side of a stable chassis200, on which rod in a height-displaceable manner a socket110is mounted with the training unit overhead, for practicing serve strokes. On the other side of the chassis200, an identical training unit, for example, corresponding toFIG. 1, is mounted preferably detachably corresponding toFIG. 7, for practicing forehand and backhand strokes.

In contrast to the training unit on the left side inFIG. 8, in which the section rod3substantially swivels back by its own weight into the initial position, in the case of the overhead arrangement a return spring115is provided on the right side, which, after a serve stroke is carried out, returns the section rod3back into the raised initial position ofFIG. 8.

For training serve strokes, inFIG. 8a ball1having a rotational axis2perpendicular to the plane of the drawing is mounted at the connecting member20, so that preferably cannonball serves can be practiced. In order that kick and slice serves can also be practiced, the connecting member20is twisted in different directions, asFIG. 9shows, so the axis2of the rotatable support of the ball no longer lies vertically to the plane of the drawing as inFIG. 8, but inclined thereto, when a connecting member20a, represented inFIG. 9, which is twisted and has an approximately rectangular cross-section, is mounted at the section rod3.

FIG. 9aschematically shows an inclined position of the rotational axis2to the longitudinal direction of the section rod3when using a twisted connecting member20ainFIG. 9. In the case of a kick serve, the rotational axis2of the ball1is approximately 5 to 1° steeper in relation to the longitudinal axis of the section rod3.

Different embodiments of the described constructions are possible. For example, inFIG. 8, the training unit mounted upright can be mounted on the left side, also in a height-displaceable manner, at the chassis200.

The holding devices of the ball described by means ofFIGS. 5, 6 and 9can also be mounted at a different construction of a tennis training device than the one described.

For the design of the damper10aat the second stop9, a spring surrounded by an elastomeric material can also be used.

FIG. 2shows a spring4cbetween section rod3and left support, so that the section rod is resiliently supported when swiveling back.

FIG. 10shows a cross-section through a ball having a radially protruding, elastic extension1a. A mushroom-shaped part1a,1bmade of rubber material is inserted into a ball divided, for example, into two halves, wherein the extension1aextends through a bore in the circumferential surface of the ball. The plate-shaped part1bof the mushroom-shaped insert is adhered on the inside of the ball or joined to the rubber material of the ball by vulcanizing. Preferably, a loop or a hook member is mounted at the end of the elastic extension1a, at which loop or hook member a tensioning member can engage and can be hooked on for placing the ball under tension at the support bar5or at the section rod3as shown inFIG. 6.

A bore or a slot can be provided at the plate20.3of the connecting member20, through which bore or slot the extension1aor the tensioning member fixed at the extension1aextends.

FIG. 10ashows a preferable embodiment of the mounting of a ball on a connecting member20, wherein the ball1abuts on the plate20.3and the extension1aextends through a bore in the plate20.3.