WO2002053233A2

WO2002053233A2 - Tennis racket

Info

Publication number: WO2002053233A2
Application number: PCT/CZ2002/000001
Authority: WO
Inventors: Ladislav Hrabal
Original assignee: Ladislav Hrabal
Priority date: 2001-01-05
Filing date: 2002-01-04
Publication date: 2002-07-11
Also published as: CZ296870B6; CZ200156A3; WO2002053233A3

Abstract

Tennis racket with a head (13) being connected, by means of a throat (13a), to a supporting tube (3) placed in a hollow tubular handle (1) for angle-limited and, in its extreme positions, lockable turning of the head (13) against the handle (1) is equipped, according to the invention, with a controlling socket (2), mounted to the supporting tube between the head (13) and the handle (1) in a revolving manner, the free end of the controlling socket (2), reaching between the handle (1) and the supporting tube (3), forms a gear cage (2b) of two-way overrunning clutch (4) which outer ring is formed by the handle (1) and its inner ring is formed by the supporting tube (3) in order to optionally provide for mutual grip of the handle (1) and the supporting tube (3) or for free carrying of the supporting tube (3) with the controlling socket (2) in both rotation directions whereas the other free end of the controlling socket being adapted to a handle to be gripped with the tennis player's hand. Advantageously, at least a stop (7) reaching to the radial recess (8) in the handle (1) or in the controlling socket (2) may be installed in the supporting tube (3) in order to set the extreme positions of turning of the head (13) against the handle (1).

Description

Tennis racket

Description

The invention relates to a tennis-racket with its head being connected, by means of a throat, to a supporting tube which is fitted in a hollow tubular handle for angle-limited and, .in its extreme positions, lockable turning of the head against the handle.

Correct grip of the tennis racket in the hand of a tennis player is of great importance for the player's success, in particular due to the fact that modern tennis is very hard and fast. There are high demands on the tennis racket grip from the view of its simplicity, speed and accuracy. The existing grip change from backhand to forehand does not guarantee keeping of equivalent grip positions which negatively influences the accuracy of the drives, especially when the player- has to follow the movement of the ball and the grip change is carried out without any optical control. The surface area of the tennis racket handle is also disadvantageous: it is shaped as multi-edged cylinder but, due to the grip change, it must be symmetrical along the axis of that cylinder and thus it cannot be shaped ergono ically. In the patent US 4101125, a tennis racket is described, with its head with stringing forming a single piece with a cylindrical throat and its handle having a hollow cylinder shape. The free end of the cylindrical throat is inserted in that hollow cylinder. The handle is placed at the free end of the cylindrical throat in a revolving manner and may be shifted in the direction of the axis, with a U-shaped radial slot made in the handle and a radial pin protruding in radial direction from the cylindrical throat and reaching the slot. There is an axial compression spring that is installed at the bottom of the handle forming the hollow cylinder at the free end of the cylindrical throat. The U-shaped radial slot provides for two stable pin positions between which the handle and the cylindrical throat may be rotated in such manner that in the first position the hand of a tennis player presses against the cylindrical throat to the handle, turns slightly the throat against the handle from one extreme position to another and then releases the pressure between the handle and the cylindrical throat in order to release the axial spring inducing an axial movement of the pin in. the U-shaped slot into the other position. The rotation from one position to another needs, in addition to the rotation itself, an induction of a mutual axial movement of the handle and the cylindrical throat of the tennis racket. However, such movement is not natural and it is not always feasible in time due to the high speed of the modern tennis play. The aim of this invention is to eliminate the drawbacks of the existing technology and provide for such tennis racket that could provide for an easy and quick grip change from backhand to forehand positions and vice versa, would have an advantageous ergonomic shape of the handle and would be simple and reliable.

The disadvantages of the existing state of technology are substantially eliminated and the objective of the invention is fulfilled with a tennis racket with its head being connected, by means of a throat, to a supporting tube which is fitted in a hollow tubular handle for angle-limited and, in its extreme positions, lockable turning of the head against the handle according to the invention consisting in that on the supporting tube, between the head and the handle, a controlling socket is mounted in a revolving manner, whose one of its free ends, reaching between the handle and the supporting tube, forms a gearing cage of a two-way overrunning clutch, which outer ring is formed by the handle and its inner ring is formed by the supporting tube optionally for mutual grip of the handle and the supporting tube or for a free carrying of the supporting tube with the controlling socket in both rotation directions, the other free end of the controlling socket being adapted to a handle to be gripped by with the tennis player's hand. In- the supporting tube at least a stop protruding to the radial recess in the handle or in the controlling socket in order to define the extreme positions of the head-to-handle rotation may advantageously be inserted. The tennis racket according to the invention provides for accomplishment of a higher sense of the play and a higher accuracy of drives which results in a higher amount of drives being played with the centre of the stringing and a lower load of the tennis player' s arm and an overall more pleasant tennis play.

The tennis racket according to the invention is shown in the designs, where Fig. .1 indicates the general view of the tennis racket, Fig. 2 a longitudinal section of the tennis racket in the area of the handle, Fig. 3a a cross section of the two-way overrunning clutch in the arrested position, Fig. 3b a cross section of the two-way overrunning clutc in the released position and Fig. 4 a cross section of the handle in the area of the radial recess. In accordance with Fig. 1, the tennis racket consists of a head 13, which is firmly connected to a throat 13a, which is inserted into a cylindrical handle 1 with its extended end 13b. On the throat 13a, a controlling socket 2; protruding into a cylindrical handle 1 is mounted. At the end of the handle 1 there is a lower cap 9_. There is a central cap 12_ between the handle and the controlling socket and packing between the controlling socket 2 and the throat 13a. The central cap 12_ and the packing 11 are designed for sealing of the inner space between the handle 1 and the throat 13a. According to Fig. 2, the throat 13a of the tennis racket is terminated with a cylindrical stem 13b onto which a supporting tube 3_ is firmly attached. The supporting tube 3_ protrudes into the cylindrical handle 1. On the supporting tube 3_ the controlling socket 2 is mounted in a revolving manner; with its cylindrical end, the controlling socket protrudes between the supporting tube 3_ and the cylindrical handle ^L. This free end of the controlling socket 2. is part of a two-way overrunning clutch, which is located between the supporting tube 3_ and the cylindrical handle 1 and forms a gearing cage 2b of the two-way overrunning clutch 4_. The outer ring of the two-way overrunning clutch 4_ is firmly connected to the handle or, possibly, may directly be formed by the supporting tube _3. The handle 1 is mounted on the supporting tube 3 in a revolving manner using an inner bearing 5_ and outer bearing 6 that in principle correspond to a common mounting practice, e.g. that of automobile water pump spindle or textile machine spindle. Respecting the necessary load capacity, the seating may . consist of e.g. two lines of balls or one line of balls with four-point contact and a line of small cylinders, possibly balls, or the seating may be sliding or it may consist of a combination of a rolling line and a sliding socket. The rolling bodies may be provided with or without a cage; the latter case brings a higher load capacity. The rolling body / sliding socket lines should be located within a maximum designing spacing due to seating rigidity; also, it should be taken into account, that the inner bearing 5_ load is higher than that of the outer bearing 6. In the inner surface of the handle 1_ the two-way overrunning clutch is seated, its rolling cylinders being in contact with the supporting tube 3_ that • is appropriately shaped here. In the two-way overrunning clutch _4 the handle 1 and the supporting tube 3_ are mutually gripped. However, the two-way overrunning clutch _4 enables free carrying of the supporting tube 3_ by means of the gearing cage 2b in both rotation directions, that means slight rotation of the handle 1 against the supporting tube 3_ in both rotation directions by means of the controlling socket 2 . Without any- action to the controlling socket 2 , the supporting tube 3_. cannot be turned against the handle _1 since the movement is blocked by the above-mentioned system of two-way overrunning clutch 4_. The gearing cage 2b of the two-way overrunning clutch 4 is made of a free end of the controlling socket which is guided on the supporting tube 3 in a revolving manner arid is suitably channelled or shaped in any other manner or suitably wrapped in order to be gripped by the tennis player' s hand. The system of the extreme position adjustment may conveniently be solved using a recess 8_ in the handle 1 or the controlling socket 2 in the lower part and one or two radial pins embedded in the supporting tube 3_. Other adjacent holes in the supporting tube 3 provide for the possibility to adjust the radial pins 3 in other positions. The player may arbitrarily choose those positions in accordance with his own preferable limited extent of the rotation of the racket head against the handle. The possible supplementary system of intermediate positions- may utilize the known arresting element similar to the gear arrest of the automobile gear boxes with cushioned protruding ball; such element may be built in the controlling socket 2 or the supporting tube 3_ or the handle 1 with corresponding arresting dents of spherical shape in the respective opposite parts. The lower cap _9, the upper, packing 11 and the central, cap 12 protect the sliding / rolling seating parts against dirt and dust. The player may change the position of the racket head 13_ against the handle 1 with his free hand, rotating the controlling socket 2_j_ which is between the handle 1 and the throat 13a of the racket or the supporting tube 3_, respectively. The extent of the extreme positions is given by the adjustable position of the radial pins 1_ and the length of the radial recess 8_ in the handle 1. The extreme positions represent stops behind which the racket head 13_ cannot be rotated. In addition to those adjustable positions some intermediate positions may be preset by introduction of arresting elements. However, such positions do not represent full stop and they only serve to player' s sense orientation in order to assess the position of the head 13_ turning against the handle 1. The adjustable position is blocked with the built-in two-way overrunning clutch _4 until a new adjustment, using the controlling socket 2__r is carried out because such rotation of the controlling socket 2_ is not limited with the arresting element. The two-way overrunning clutch 4_ provides for arresting position between the handle 1 and the supporting tube' 3 / stem 13b of the throat 13a only. This enables arrest of the racket head 13 against the handle 1 in the moment of the drive; between the respective drives, however, the position- may be arbitrarily adjusted using the controlling socket 2 . In connection to the existing shape of the tennis rackets and due to the fact that the mutual rotation of the controlling socket 2_ and the supporting tube 3_ / racket head _13 is minimum on practice, the controlling socket 2_ may copy the racket throat 13a shape with appropriate air-space (Fig. 2). In Fig. 3a and 3b the function -of the two- way overrunning clutch, to be used according to the invention, is explained. As it is shown in Fig. 3a, the two-way overrunning clutch comprises a system of couples of small cylinder 14a and 14b; the cylinders are pushed away from each other to a narrowing area by means of a spring _4a, i.e. they are pushed in the locking position. This spatial narrowing area is created by both inner circular shape of the handle 1 and by the inclination of the protruding clamping areas 3b of the supporting tube 3_. The mentioned locking disables any turning of the handle 1 against the supporting tube 3_ and against the racket head 13_ respectively, in both directions. According to the Fig. 3b, . the primary rotation of the controlling socket 2_ against the supporting tube 3_ in the direction shown enables the small cylinders 14a to be released from their arresting positions by^' means of the gear cage 2b which passes to the controlling socket 2. During rotation with the gear cage 2b the gearing edges 2a push the respective cylinders 14a from the arresting positions while the other cylinders of the pairs 14b are not arrested in their positions during the shown rotation direction. During the additional rotation of the gear cage 2b also the supporting tube 3_ is rotated by means of a tooth system 2c engaging in the recesses of the supporting tube 3. The principle of other direction rotation works in a symmetrical manner. This system assures fixing of the mutual position of the handle 1 against the supporting tube 3_ or the rocket head _13 respectively, any possible change of this position being possible using the rotation of the gear cage 2b i.e. by the controlling socket ^• 2. According to Fig. 4, the position of the pins determines the possible mutual rotation of the handle 1 against the supporting tube _3. In the supporting tube 3 there is a system of holes for an arbitrary placement of pins 7_ which represent stops in connection to the recess 8_ in the handle _1 during the rotation of the handle _1 against the supporting tube 3_- ^Tne rotation of the handle 1 against the supporting tube 3_ is limited by the free space between the adjustable pin 7_ and the edge of the recess 8a in the handle 1^ This system provides the player to be able to easily and accurately reach the required ultimate position, e.g. the backhand position and then immediately the forehand position and vice versa, by rotating the controlling socket 2 , i.e. the supporting tube 3_ . against the handle 1_^. The desired angles may be adjusted in both rotation directions by changing the respective positions of the adjustable pins _7 in connection to the range of the created radial recess 8_. Also, another solution may be offered: a single steady pin (a stop) 1_ and a mechanically adjustable recess edge position 8a.

Claims

Patent claims

1. Tennis racket with a head (13) connected by means of a throat (13a) to a supporting tube (3) fitted in a hollow tubular handle (1) for angle-limited and, in its extreme positions, lockable turning of the head (13) against the handle (1) , c h a r a c t e r i z e d i n t h a t on the supporting tube (3) between the head (13) and the handle (1) is provided a controlling socket (2) , mounted in a revolving manner, which free end reaching between the handle (1) and the supporting tube (3) forms a gear cage (2b) of a two-way overrunning clutch (4) which outer ring is formed by the handle (1) and its inner ring is formed by the supporting tube (3) in order optionally to provide for mutual grip of the handle (1) and the supporting tube (3) or for free carrying of the supporting tube (3) with the controlling socket (2) in both rotation directions whereas the other free end of the controlling socket (2) being adapted to a handle to be gripped with the tennis player's hand.

2. Tennis racket according to the claim No. 1, c h a r a c t e r i z e d i n t h a t in the supporting tube (3) is provided at least a stop (7) protruding into the radial recess (8) in the handle (1) or into the controlling socket (2) for setting the extreme positions of the head (13) turning against the handle (1) .