WO2002011824A2

WO2002011824A2 - Device and method for measuring rackets

Info

Publication number: WO2002011824A2
Application number: PCT/CH2001/000476
Authority: WO
Inventors: Ulrich H. KÜHNEL
Original assignee: Xception Sports Technologies License Ag
Priority date: 2000-08-03
Filing date: 2001-08-03
Publication date: 2002-02-14
Also published as: AU2001281625A1; WO2002011824A3

Abstract

The invention relates to a device and method for measuring rackets, especially tennis rackets. A racket (20) is strung by means of a stringing device (1). This stringing device (1) comprises a stringing frame (2) with fastening means (13, 14), which serve to temporarily fasten the racket (20) to the stringing frame (2). The stringing device also comprises a pulling device (3) that is suited for pulling a string (22). By using a load cell (24), the force (23) exerted onto the string (22) by the string clamping device (25) is measured and is individually monitored by a control.

Description

DEVICE AND METHOD FOR SIZING

RACKETS

The invention is in the field of racquets, respectively. Rackets for ball games, such as those used for tennis, squash or badminton.

Tennis, squash and badminton rackets have a frame with a covering. This string usually consists of an endless string, which is braided through holes provided in the frame, so that it forms a network.

Coverings are typically manufactured manually today. For this purpose, the frame of the racket is usually clamped in a stringing device in order to tension the string by hand or with the help of a machine. Corresponding coverings, however, have the disadvantage that the strings are processed in an uncontrolled (undefined) manner. Certain strings therefore have unfavorable tensions compared to their neighbors, making the racket difficult to control. The sweet spot is therefore correspondingly small and there are health effects on the health of the player (blow arm). The deflection (deflection) of the string bed is difficult to control. This is particularly disadvantageous in competitions.

BESTATIGUNGSKOPIE Each racket has an individual shape and size. Depending on the area of application, different construction methods are used, which means that each racket has its own characteristics. In the conventional methods, these parameters are not taken into account, or only insufficiently, so that the coverings are not optimized and a racket cannot be used in the best possible way. Incorrectly strung rackets also cause secondary tension and non-harmonic vibrations of the string bed. The negative circumstances have a negative impact on the life of the racket and the strings as well as the health of the player. The joints of the striking arm in particular are subject to increased wear and tear and the risk of injury increases.

It is the object of the invention disclosed here to show a method and a device by means of which an optimized covering can be produced in a racket, in particular for tennis, squash, etc., in such a way that the problems known from the prior art are largely avoided become. The object is achieved by the invention according to the patent claims.

The invention disclosed here is based, among other things, on the fact that characteristic map data and characteristic maps are determined and used for dimensioning clothing. To determine the map data, important influencing factors of the racket, such as the area of the racket (string bed), length, width, etc., as well as the strings (number, elasticity behavior) are taken into account. The values of the map data are preferably generated arithmetically, by means of tests or by measurements. Calculations are preferably carried out using a computer which has suitable programming. The maps are created individually for racquets of different characteristics and recorded in a suitable form. This makes it possible to tension strings in such a way that, depending on their location, they have an optimal tension / stretch behavior in conjunction with their neighbors. Further advantages are that a covering is reproducible and that a corresponding one String bed has a defined surface hardness value that can be adjusted according to a customer's request. If necessary, the optimal string tension can be determined using the surface hardness value.

When generating map data by calculation, depending on the desired goal, physical models are used which make a statement about the optimal tension distribution in a string as a function of parameters of the racket and the string. One approach to a suitable physical model is e.g. in that a cross string under a certain force experiences the same deflection as a main string (and vice versa). From these conditions there are setpoints for the tension of each string, respectively. each string section of a particular racquet. The results are recorded as a component of map data in a corresponding map.

In order to provide a certain racket with a covering according to the invention, map data (setpoints) contained in a specific map are transferred to the racket by means of a device according to the invention. The optimal tension values for the covering, resp. the string sections determined. With this procedure the behavior of a racket is optimized and adapted individually. In particular, customer requests can be taken into account in a defined manner. The required target value of the string tension of a section of string can be calculated individually from a desired surface hardness value. Optimized sizes of the sweet spot can be achieved with the invention disclosed here.

The map data compiled into maps are stored in a suitable form and on a suitable storage medium, for example as a file in a computer or in a central database (can be called up regardless of location). These files include hold, for example, information about the balance of forces in the individual string sections, geometry data, etc. Rackets are preferably marked in such a way that they can be clearly identified. It is possible to save all relevant data on the racket (barcode, chip) or, for example, on a chip card. As an alternative or in addition, a database can be used which contains relevant data and preferably makes it accessible regardless of location (e.g. via an internet connection). In this case, a marking in the area of the racket is sufficient, which assigns a racket to the corresponding information in the database. As a rule, specific customer data (gaming assets, etc.) are also taken into account.

The rackets covered according to the method disclosed here are additionally used, e.g. for promotional purposes, marked. Using a suitably combinable color application device, a logo can be applied to the covering to mark the racket. A corresponding device can be combined with the device described here. As an alternative or in combination, suitable packaging, e.g. in the form of a transparent plastic film with a print, usable.

To determine a condition of a racket, respectively. if necessary, means can be provided by means of which the deflection of the covering as a function of the force can be recorded at different points. These data are particularly suitable for recording and evaluating the condition of an existing covering, for example to determine whether a renewal is necessary or whether the map data is correct. It can also be checked whether a newly covered racket has been covered properly. In addition, it is possible to provide means for determining the club weight, the center of gravity, the inertia, etc. The data and measured values are preferably recorded and evaluated by means of a computer. If desired, the stringing device has means for measuring the required string length. It can be this For example, they are two cooperating roles, one of which is driven and the other serves as a measuring role. The reels are advantageously operatively connected to a control (the stringing device, customer advice center) in such a way that the string to be measured can be inserted between the two reels and can be measured automatically.

The invention is illustrated by the following figures.

Figure 1 shows an inventive device in a perspective

Presentation;

FIG. 2 shows a detail of the device from FIG. 1 in an enlarged representation.

FIG. 1 schematically shows a preferred embodiment of a covering device 1 according to the invention for covering rackets in a perspective view. A covering frame 2, a pulling device 3 and a display means 4 can be seen. The covering frame 1 here has a base plate 10, a substructure 11 and a bearing axis 12, as well as a first 13 and a second fastening means 14 and four rods 15 which can be displaced transversely to their longitudinal direction , 16, 17, 18 (cf. FIG. 2), which are attached below the base plate 10, two of which here each have an angle of approximately 90 ° to one another. The covering tion frame 1 is rotatable about the bearing axis 12 on a work table (not shown), for example by means of a ball bearing, so that the racket 15 can be brought into a most favorable position during a covering process.

The fastening means 13, 14 serve for the temporary fastening of a racket 20 on the base plate 10 of the covering frame 1 above an opening 19. The opening 1 is arranged in such a way that a covering 21 to be attached in the racket 20 (shown here in the making) is from both sides is editable. The covering 21 is generally produced from a string 22 in which it is braided through holes (not shown in more detail) that are usually made in the frame of the racket and run approximately radially. In the situation shown here, the string sections running in the longitudinal direction of the racket 20 are first created. After being drawn through the corresponding openings, each string section is fed to a string clamping device 25, which is attached here to the upper end of a slide 30 of the pulling device 3. The string clamping device is arranged here in such a way that the string 22 to be tensioned can essentially be pulled in the direction of the corresponding holes in the frame of the racket 15 (at the same height).

A string section to be tensioned is tensioned by means of the string clamping device 25 until a predetermined target value is reached. The predetermined target value is determined according to the length of the string section to be processed, in such a way that optimal behavior is achieved in conjunction with the adjacent strings. The data required for this are usually determined using a map.

The carriage 30 is mounted in such a way that it follows a linear guide 31, which is firmly connected to the work table (not shown in more detail), in the direction of an arrow 32 can be moved. The carriage 30 is operatively connected via a spindle 33 to a motor 34, which is also firmly connected to the work table (not shown in more detail), such that the carriage 30 is moved linearly relative to the racket 20 by means of the motor 34 in the direction of arrow 32 can.

The string clamping device 25 here consists of two clamping jaws 26, 27 which are arranged such that they act self-locking when a string is clamped. A string section to be tensioned is inserted between the clamping jaws 26, 27 of the string clamping device 25. The clamping process is triggered by actuating a switch 28, which is arranged here behind the clamping device 25. The switch 28 is arranged such that it can be actuated by pulling down the string section 29 projecting behind the clamping device 25. If necessary, other means can be provided to trigger the tensioning process. The switch 28 may e.g. can also be used to trigger an emergency stop if necessary.

When the switch 28 is triggered, the motor 35 and with it the carriage 30 are set in motion. The entire process is preferably monitored and controlled via a programmed controller, which is not shown here. The control uses the motor 34 to move the slide 30 and the string clamping device 25 operatively connected to it at a certain speed in the direction of the arrow 32 from the racket 15. The clamping jaws 26, 27 are made to close by a trigger mechanism (not shown), which contains, for example, an electromagnet. As a result, the string section lying between the clamping jaws 26, 27 is clamped. The clamping jaws 26, 27 are designed in such a way that the clamping effect increases in accordance with the force acting on the string 22 (self-locking). The tensile force acting on the string 22, represented schematically by an arrow 23, is measured via a load cell 24 which is operatively connected to the clamping device, and one with the control coupled data acquisition and evaluation unit (not shown). This data acquisition and evaluation unit evaluates the measured values of the load cell 24 and compares it here with a preset target value. If this setpoint is reached, the string is loaded up to a certain value (stretching process) before it is set to the setpoint. This guarantees that, among other things, the quality of a covering will last in the long term. The speed curve driven is set according to the requirements. In order to temporarily fix the string 22 in its end position, a first clamp 40 is attached to one of the displaceable rods 15, 16, 17, 18 and the string 22. If necessary, the string 22 can also be fixed locally to the frame of the racket 15 using appropriate means, for example in the area of the holes in the frame of the racket (not shown in more detail).

One way of calculating the initial string tensions is to determine them in such a way that a short string with the same force experiences the same deflection as a long string with the same force. The values required for this are usually determined depending on the geometry of a racket and in a suitable form, e.g. stored in a database in conjunction with other data. A racket can be identified accordingly by means of a reference (e.g. bar code marking, chip card, chip) in such a way that the relevant data can be assigned.

The user of the device 1 is instructed on the display means 4 which string is to be tensioned. For this purpose, a frame of a racket 36 is shown schematically in the embodiment shown here. In this frame, information 37, for example, flashes that provide information about which section of the string is to be created in the next work step (stringing scheme). Other relevant data such as recommended string type, total string length and per section, string numbers (lengthways, crossways), weight of the racket, size, balance point, etc. can also be if represented. The data are coordinated with the racket to be covered. If desired, information 38 about the clamping process is shown on the display means. The desired and the current value of the string tension is displayed. The display means 4 is preferably a touch screen panel on which operating elements 39 can be displayed, by means of which the work flow and the control of the covering device can be influenced.

The display means 4 is connected here to the control (not shown) covering device 1 and to a computer (not shown) which can be used to record customer data and provide individual support. There is also an active connection between the computer for recording customer data and the control of the covering device 1. Data or measured values exchanged via a racket 15. A data acquisition device, e.g. a barcode reader pen (not shown in detail) or a laser scanner (not shown in detail) are also coupled to the computer for recording customer data and / or controlling the covering device. The data acquisition device is used here, for example, to identify a marked racket or to determine other relevant data, as well as to operate the covering device 1. Information about rackets can be present in a booklet in a printed form, for example, and assigned to the covering device 1 with a bar code , If necessary, it is possible to operate the covering device 1 without a computer for recording customer data.

FIG. 2 shows a section of the covering device 1 in FIG. 1. The covering frame 2 with the racket 15 fastened thereon can be seen in a perspective view. The detail D shows the first fastening means 13, which is used for the temporary clamping of the racket 15 on the base plate 10, in an enlarged representation. On the base plate 10, an element 45 is fastened, which NEN cross-section, which cooperates with a base 46 of the first fastening means 13 such that the base 46 is displaceable in the direction of an arrow 47. It is thus possible to adapt the effective range of the first fastening means 13 (the same applies to the second fastening device 14) to a size of a rocket 15. The fastening means 13, 14 are designed such that they do not hinder a covering of the racket. In the embodiment shown here, they have a threaded pin 48 which is fastened on the base 46 and can be operatively connected to a counterpart 49 and a knurled screw 50 such that a frame of the racket 15 can be temporarily tightened.

The base plate 10 has holes 55 which are suitable for receiving a deflecting roller 56. The deflection roller 56 serves to tension the string 22 with the pulling device 3 (cf. FIG. 1) in an optimal direction (e.g. shortest path) in such a way that friction which hinders it is avoided.

Below the base plate 10, four rods 15, 16, 17, 18 (not visible) which can be displaced transversely to their longitudinal direction can be seen. These rods 15, 16, 17, 18 are fastened in linear bearings (not shown in detail) below the base plate 10 and can be moved transversely to their longitudinal direction and parallel to the surface of the base plate 10. They serve for the temporary fastening of a first and a second clamp pliers 40, 41 while stringing the racket 15, so that the tensioned string sections can no longer slip. The clamping pliers 40, 41 serve as holding means and are arranged in such a way that they do not hinder the covering process.

In the situation shown here, the string sections are in the longitudinal direction of the

Rackets 15 shown. After these are completed, appropriate string sections with individually adjusted string tensions in the transverse direction woven. In order to make this work process as frictionless as possible, an expansion device (inverse) is used, which can be integrated in the covering device and can, for example, interact with the displaceable rods 15, 16, 17, 18. Alternatively, a separate standard spreading device can be used.

Claims

PATENT CLAIMS

1. stringing device (1) for stringing a racket (20), in particular a tennis racket, with a string (22), comprising:

a) a covering frame (2) with a fastening means (13, 14), which serves for the temporary fastening of the racket (20),

b) a pulling device (3) for pulling the string (22), with a string clamping device (25) and a motor (34), which serves for the relative displacement (32) of the string clamping device (25) relative to the stringing frame (2), and

c) a load cell (24) which is used to measure the force (23) exerted by the string clamping device (25) on the string (22).

Stringing device (1) according to claim 1, characterized in that a control is provided which serves to monitor and control the force (23) exerted on the string (22).

3. stringing device (1) according to one of the preceding claims, characterized in that a deflecting roller (56) is provided, which serves for the temporary deflection of the string (22).

4. stringing device (1) according to one of the preceding claims, characterized in that a display means (4) is provided which serves to display information about a string section to be tensioned and / or a force (23) exerted on the string (22) ,

, Covering device (1) according to claim 4, characterized in that the display means (4) is a touch screen panel which has operating elements (39) for influencing the covering device (1).

Covering device (1) according to one of the preceding claims, characterized in that the covering device (1) is connected to a computer which contains information about customers and / or rockets.

7. covering device (1) according to one of the preceding claims, characterized in that the covering device (1) is connected to a data acquisition device.

8. covering device (1) according to one of the preceding claims, characterized in that the covering frame (2) has a rod (15) which is displaceable transversely to its longitudinal direction and which is used for the temporary fastening of a clamp (40, 41).

9. stringing device (1) according to one of the preceding claims, characterized in that a spreading device for spreading string sections is present.

10. stringing device (1) according to one of the preceding claims, characterized in that a storage medium is present which contains target values for tensions for different string sections.

11. stringing device (1) according to claim 10, characterized in that the target values are correlated with the length of string sections.

12. stringing device (1) according to one of the preceding claims, characterized in that a switch (28) is present which can be actuated by means of a string section (29) and which serves to trigger and / or cancel a tensioning process of the string (22) serves.

13. A method for stringing a racket (2), in particular a tennis racket, characterized in that during the tensioning of a string (22) the force (23) exerted on the string (22) is measured, the measured value with a

Setpoint value compared and this comparison value is used to control the force (23) exerted on the string (22).

14. The method according to claim 13, characterized in that the force (23) exerted on the string (22) is increased above the desired value in order to stretch the string and that the force (23) exerted on the string (22) later the setpoint is set.

15. The method according to any one of claims 13 or 14, characterized in that a map is formed which contains information about string tensions.

16. The method according to claim 15, characterized in that a setpoint is taken from a map that contains setpoints for different string sections.

17. racket (20), in particular tennis racket, with a covering (21), characterized in that the racket (20) is covered with the method according to one of the claims 13 to 16.

18. covering system for covering a racket (20), in particular tennis rackets, characterized in that the covering system has a covering device (1) which is connected to a computer which contains information about customers and / or rackets, the information between the Computer and the covering device (1) are transmitted.

19. Stringing system according to claim 18, characterized in that the information transmitted between the computer and the stringing device (1) is used to determine the tension of a string (22).