EP0162794A1 - Verfahren zur Messung der Spannung der Besaitung eines Schlägers und Vorrichtung um dieses Verfahren durchzuführen - Google Patents

Verfahren zur Messung der Spannung der Besaitung eines Schlägers und Vorrichtung um dieses Verfahren durchzuführen Download PDF

Info

Publication number
EP0162794A1
EP0162794A1 EP85440019A EP85440019A EP0162794A1 EP 0162794 A1 EP0162794 A1 EP 0162794A1 EP 85440019 A EP85440019 A EP 85440019A EP 85440019 A EP85440019 A EP 85440019A EP 0162794 A1 EP0162794 A1 EP 0162794A1
Authority
EP
European Patent Office
Prior art keywords
vibrations
frequency
racket
string
tension
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP85440019A
Other languages
English (en)
French (fr)
Inventor
Jacques Morel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Morel Technic Sarl
Original Assignee
Morel Technic Sarl
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Morel Technic Sarl filed Critical Morel Technic Sarl
Publication of EP0162794A1 publication Critical patent/EP0162794A1/de
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A63—SPORTS; GAMES; AMUSEMENTS
    • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
    • A63B51/00—Stringing tennis, badminton or like rackets; Strings therefor; Maintenance of racket strings
    • A63B51/005—Devices for measuring the tension of strings

Definitions

  • the present invention relates to a method for measuring the stringing tension of a racket, in particular a tennis racket, as well as an apparatus for implementing this method.
  • Known methods of controlling the tension of the string of a tennis racket usually consist in applying a determined load to the string of the racket clamped by its handle, measuring the arrow and determining the value of this tension at the using a table of references providing a value of the tension according to the value of the deflection.
  • the object of the present invention is to overcome this drawback by proposing a method as mentioned above, as well as an apparatus for implementing this method, making it possible to determine with great precision the stringing tension of the rackets, whatever the type or dimensions of the frame, and in a particular application to use the values of the tension thus determined to control a stringing machine.
  • the measurement method according to the invention is characterized in that the racket is clamped on a support by its handle, in that the string is struck with a weight to do it vibrate, in that the frequency of the vibrations of this string is detected, and in that the voltage is determined as a function of the frequency of these vibrations.
  • the frequency of the vibrations is detected by capturing the variations in the air pressure generated by the vibrations of the rope using a vibration sensor, and the frequency is determined. of these variations using a frequency meter.
  • the tension of the racket string is advantageously displayed on a digital display screen, this ten sion having been previously determined by an electronic circuit taking into account the characteristics of the frame of this racket.
  • the racket string tension can also be determined using a standard graph representing the variation in the frequency of vibrations as a function of string tension for at least one specific type of racket frame.
  • a racket stringing machine is controlled as a function of the tension determined by measuring the vibration frequency of the string.
  • the apparatus for measuring the stringing tension of a racket is characterized in that it comprises a support equipped with means for clamping this racket by its handle, a weight for vibrating the string, a member for sensing the vibrations of the string, means for determining the frequency of these vibrations and means for deducing the value of the string tension of the racket as a function of the value of the frequency of said vibrations.
  • the member for picking up the vibrations of the rope comprises for example an acoustic sensor, and the means for determining the frequency of the vibrations of the rope comprise a frequency meter arranged to determine the frequency of the signal emitted by this sensor.
  • the means for determining the frequency of the vibrations of the rope advantageously comprise an electronic circuit arranged to isolate a signal corresponding to the vibrations of the rope and to eliminate the spurious signals corresponding to the vibrations of the frame and the parts attached to this frame.
  • the electronic circuits include means for determining the value of the string tension as a function of the value of the frequency of vibrations of this string and according to parameters depending on the frame of the racket.
  • the electronic circuit preferably comprises means for transmitting a control signal to this stringing machine as a function of the value measured the frequency of vibrations.
  • the device shown comprises a base 10 on which is mounted a support 11 equipped with a quick clamping jaw 12, associated with a locking screw 13 making it possible to clamp a racket 14 by its handle 15.
  • the racket is kept cantilevered on the support 11 so that its string 16 is disposed above an acoustic sensor 17 incorporated in the base 10.
  • this same base 10 also carries a small counterweight 18 fixed to the end of a handle, constituting a small removable hammer of low mass, with the help of which the operator can strike the line 16 to vibrate.
  • a racket scale 19 can be mounted on the base 10 to assess the weight of the racket and thereby determine one of the parameters which can be taken into account by the circuit of the apparatus when determining the string tension.
  • the circuit 20, of which FIG. 2 represents a block diagram is represented diagrammatically by a vertical plate integral with the support 11 and carries a display screen 21, constituted for example by a display with light-emitting diodes, intended to effect the digital display the value of the string tension, measured by means of the circuit described below.
  • the. signal emitted by the frequency meter can be used directly for the control of a racket stringing machine.
  • the present invention is not limited to the embodiments described, but can undergo different modifications and come in various variants obvious to those skilled in the art.
  • the acoustic sensor could be replaced by various other types of vibration sensors such as for example optical sensors, accelerometers.
  • the device described could be equipped with a unit for calculating and processing information which stores a certain number of parameters which the operator can enter using a keyboard of the alpha-numeric type.
  • parameters which can be stored on a printed card or on a magnetic card are, for example, the diameter of the rope, the nature (natural or synthetic hose, type of frame and / or material used, humidity, etc.).

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Biophysics (AREA)
  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Physical Education & Sports Medicine (AREA)
  • Force Measurement Appropriate To Specific Purposes (AREA)
  • Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
EP85440019A 1984-04-05 1985-03-22 Verfahren zur Messung der Spannung der Besaitung eines Schlägers und Vorrichtung um dieses Verfahren durchzuführen Withdrawn EP0162794A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8405547A FR2562430B1 (fr) 1984-04-05 1984-04-05 Procede de mesure de la tension de cordage d'une raquette et appareil pour la mise en oeuvre de ce procede
FR8405547 1984-04-05

Publications (1)

Publication Number Publication Date
EP0162794A1 true EP0162794A1 (de) 1985-11-27

Family

ID=9302959

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85440019A Withdrawn EP0162794A1 (de) 1984-04-05 1985-03-22 Verfahren zur Messung der Spannung der Besaitung eines Schlägers und Vorrichtung um dieses Verfahren durchzuführen

Country Status (2)

Country Link
EP (1) EP0162794A1 (de)
FR (1) FR2562430B1 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3736219A1 (de) * 1987-10-26 1989-05-03 Fischer Herwig Verfahren und vorrichtung zur messung der saitenspannung eines saitenbespannten schlaegers

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2370296C1 (ru) * 2008-04-18 2009-10-20 Институт Машиноведения им. А.А. Благонравова РАН Устройство для определения динамических характеристик спортивного инвентаря
CN116712718A (zh) * 2023-07-01 2023-09-08 郑林 便携式球拍拉磅器

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3918713A (en) * 1974-03-15 1975-11-11 Bernard Kaminstein Racket stringing machine
US4103546A (en) * 1976-09-22 1978-08-01 Robert Hickey Tennis racquet string tension gauge

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3918713A (en) * 1974-03-15 1975-11-11 Bernard Kaminstein Racket stringing machine
US4103546A (en) * 1976-09-22 1978-08-01 Robert Hickey Tennis racquet string tension gauge

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3736219A1 (de) * 1987-10-26 1989-05-03 Fischer Herwig Verfahren und vorrichtung zur messung der saitenspannung eines saitenbespannten schlaegers
WO1989003709A1 (fr) * 1987-10-26 1989-05-05 Klaus Matjasic Procede et dispositif de mesure de la tension du cordage de raquettes
US5007294A (en) * 1987-10-26 1991-04-16 Karl-Eberhard Mauve Process and device for measuring the tension of racket strings

Also Published As

Publication number Publication date
FR2562430A1 (fr) 1985-10-11
FR2562430B1 (fr) 1986-07-25

Similar Documents

Publication Publication Date Title
FR2705778A1 (fr) Procédé et appareil de mesure de masse, et balance.
JP2729960B2 (ja) 荷重をかけながら硬さを測定するための硬さ測定装置
FR2427584A1 (fr) Dispositif a fibres optiques pour la mesure de grandeurs physiques telles que la position, la vitesse, la force, la pression et autres grandeurs similaires
FR2817344A1 (fr) Penetrometre dynamique a energie variable
US5811680A (en) Method and apparatus for testing the quality of fruit
EP0513144A1 (de) Verfahren und vorrichtung zur quantitativen bestimmung der härte einer rolle.
US3690144A (en) Piezoelectric microphone
CA1256571A (fr) Procede de mesure d'une grandeur physique fournissant des donnees numeriques a partir de dispositifs de mesure de valeurs analogiques et appareil de mesure appliquant ce procede
NO890777L (no) Fremgangsmaate og innretning for optisk registrering av ruhetsprofilen av en materialoverflate.
FR2562430A1 (fr) Procede de mesure de la tension de cordage d'une raquette et appareil pour la mise en oeuvre de ce procede
JPS58500580A (ja) 走行する糸の張力測定方法及び装置
FR3084464B1 (fr) Dispositif pour evaluer la solidite d'un materiau
EP0139057A1 (de) Optischer Schwingungsanalysator
US3140604A (en) Fuzz meter
JP4263573B2 (ja) 小物品の重量測定用装置
FR2613116A1 (fr) Appareil pour inspecter le profil d'une tige, notamment une tige de commande utilisee dans un reacteur nucleaire a eau pressurisee
IL106005A (en) Method and instrument for testing the quality of fruit
US4217695A (en) Hair length measuring apparatus
Schmidt et al. Modulated photoelectric measurement of vibration
JP3802200B2 (ja) 果実の熟度測定方法と熟度測定装置
GB2068112A (en) Vibration detector
JP2546235B2 (ja) 練習用鍵盤装置
SU940075A1 (ru) Стенд дл динамической градуировки ударных акселерометров
JPS59135328A (ja) 振動検出センサ
Kitchner The measurement of hand-arm vibration in industry.

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19860728

RIN1 Information on inventor provided before grant (corrected)

Inventor name: MOREL, JACQUES