EP0172120B1 - Electronic torque wrench - Google Patents

Electronic torque wrench Download PDF

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Publication number
EP0172120B1
EP0172120B1 EP85420137A EP85420137A EP0172120B1 EP 0172120 B1 EP0172120 B1 EP 0172120B1 EP 85420137 A EP85420137 A EP 85420137A EP 85420137 A EP85420137 A EP 85420137A EP 0172120 B1 EP0172120 B1 EP 0172120B1
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EP
European Patent Office
Prior art keywords
torque
value
locking force
limiting value
measured
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.)
Expired
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EP85420137A
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German (de)
French (fr)
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EP0172120A1 (en
Inventor
Georges Heyraud
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.)
SAM Outillage SAS
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SAM Outillage SAS
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Priority to AT85420137T priority Critical patent/ATE31262T1/en
Publication of EP0172120A1 publication Critical patent/EP0172120A1/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
    • B25B23/00—Details of, or accessories for, spanners, wrenches, screwdrivers
    • B25B23/14—Arrangement of torque limiters or torque indicators in wrenches or screwdrivers
    • B25B23/142—Arrangement of torque limiters or torque indicators in wrenches or screwdrivers specially adapted for hand operated wrenches or screwdrivers
    • B25B23/1422—Arrangement of torque limiters or torque indicators in wrenches or screwdrivers specially adapted for hand operated wrenches or screwdrivers torque indicators or adjustable torque limiters
    • B25B23/1425—Arrangement of torque limiters or torque indicators in wrenches or screwdrivers specially adapted for hand operated wrenches or screwdrivers torque indicators or adjustable torque limiters by electrical means

Definitions

  • the present invention relates to an electronic torque wrench.
  • This key comprises, in known manner, a drive head which cooperates with the element to be clamped and which is linked to an elongated body serving as a handle as well as housing for the electrical part, the latter comprising: a measuring bridge with strain gauges for determining the applied tightening torque, means for supplying power to the measuring bridge and the rest of the circuits, digital display means capable of indicating the value of the tightening torque, means for comparing the tightening torque measured with a prescribed limit value, and signaling means which are triggered when the applied and measured tightening torque reaches or exceeds the prescribed limit value.
  • the present invention aims to improve this kind of torque wrench, especially in terms of convenience of use, and also from the point of view of reducing energy consumption.
  • the electronic torque wrench according to the invention is characterized in that it is the digital display means which are used alternately to indicate the value of the actual tightening torque applied by means of the key, and to select and indicate the desired limit value for this tightening torque.
  • means are provided for automatically switching the display means, with passage from the indication of the limit value of the tightening torque to the indication of its actual measured value, when the latter value exceeds a predetermined threshold.
  • the display means which in any case make it possible to read the value of the actual tightening torque applied using the key to the element of the bolt, are thus also used in the invention to “program” the desired tightening torque, before using the key. This preliminary operation can therefore be carried out in a simple, rapid and precise manner.
  • the actual value of the tightening torque is displayed only from the moment it becomes significant.
  • the torque wrench comprises means for memorizing the maximum tightening torque reached, allowing the display means to still indicate the value of this torque for a certain period after the end of tightening. the display means again indicating the prescribed limit value after this period. In this way, a very brief interruption of the tightening does not cause the return to the display of the torque limit value.
  • the comparison means are arranged so as to compare on the one hand the tightening torque applied and measured with a predetermined fraction of the prescribed limit value, and on the other hand to compare the torque of applied and measured tightening with this limit value itself, the signaling means emitting a first perceptible signal when the applied and measured tightening torque reaches said predetermined fraction, by emitting a second perceptible signal distinct from the first when the applied tightening torque and measured reaches the limit value itself.
  • the operator is thus warned by the appearance of the first signal, which can be an audible alarm, that the tightening torque exerted reaches a fraction equal, for example, to approximately 9/10 of the prescribed limit value.
  • Tightening can therefore first be carried out quickly, without paying attention to the torque indication given by the display means, until the limit value approaches. Only after triggering of the first alarm signal, the operator finishes tightening more slowly and by monitoring the indication given by the display means, until the appearance of the second signal, which may be a light alarm, which indicates that the limit torque is reached and that tightening must not be continued.
  • the second signal which may be a light alarm
  • the electrical supply means of the torque wrench are arranged so as to maintain the supply of the circuits for a minimum predetermined duration, and to automatically cut this supply in the event of the key not being used at the end of this time, for example 3 minutes after start-up. Conversely, the electrical supply to the circuits of the key is maintained as long as the stopping of use of the key remains less than said predetermined duration, if a tightening cut has been applied above the threshold triggering the switching of display means.
  • the torque wrench shown in Figures 1 to 3 comprises an elongated tubular body (1), of oval section, one end of which is provided with a part (2) arranged so as to receive a removable drive head (3), adapted to the element to be tightened such as a bolt, and the opposite end (4) of which is notched and shaped as a grip handle.
  • the body (1) of the key externally comprises a series of push-buttons or control keys (5), as well as a digital display (6) for example with liquid crystals, used alternately to program the desired tightening torque and to indicate the value of the tightening torque actually applied.
  • the end of the body (1) opposite the drive head (3) is closed by a removable plug (7) giving access to an electric battery (8) which supplies the energy necessary for the various circuits of the torque wrench.
  • the part (2) which receives the drive head (3) is extended by a tail (9) embedded by two of its edges in the tubular body (1). ).
  • This tail (9) is connected, by means of a connecting pin (10), to an elongated plate (11) extending inside the tubular body (1 over a large part of the length of this last, and serving as support for the various electronic circuits (12-13) as well as for the digital display (6).
  • These electronic circuits make it possible to process the electrical signal coming from the strain gauges (14), stuck on a restricted area (9a), undergoing bending and connecting the tail (9) to the part (2) receiving the drive head (3).
  • the signal from the gauges (14) is proportional to the tightening torque applied to the handle (4 ) and transmitted by the tubular body (1) to the drive head (3) - see in particular Fig. 2.
  • Fig. 4 shows, in the form of a block diagram, the essential circuits of the electronic part of this torque wrench.
  • the amplification circuits (16) include means ensuring the rectification and switching of the reverse signal, when working the key in the opposite direction, tightening or loosening.
  • these amplification circuits ensure the switching command of the display, for the automatic passage from the indication of the programmed limit value of the tightening torque (Cm) to the indication of the measured value, therefore real of the applied tightening torque (C). This switching occurs when the torque applied by means of the key exceeds a threshold (Co) fixed for example at 15 Nm.
  • a programming control circuit (17) is associated, for example, with two of the push buttons (5), to allow rapid coarse programming, then slower fine programming of the desired limit value of the tightening torque (Cm) .
  • the programming control circuit (17) is connected to a circuit for memorizing the torque and switching the display (18), connected to the digital display (6) and making it possible to switch the indication of this display (torque programmed Cm or applied torque (C).
  • the digital display (6) itself is associated with analog-digital conversion circuits, display memory circuits (19), and circuits for erasing the memory (20).
  • the programming control circuit (17) comprises means, other than a capacitor, or accumulator, making it possible to maintain the selected state, at the value of the limit torque (Cm), for a determined time, from two to three hours, that the key is no longer used or that its means of electrical power are interrupted. This allows the predetermined programming to be maintained in the event of the key not being used or the batteries being replaced.
  • Comparison circuits (21) compare the value of the applied and measured tightening torque (C) with the torque limit value (Cm) prescribed using the programming control circuit (17).
  • the comparison circuits (21) also ensure a comparison of the value of the applied and measured tightening torque (C) with a fraction (k.Cm) of the prescribed limit value, the coefficient “k” being, for example, equal to 0.9.
  • the comparison circuits (21) are connected to signaling means (22), which may include an audible alarm (23) and a light alarm (24).
  • signaling means (22) which may include an audible alarm (23) and a light alarm (24).
  • the memory circuits (19) make it possible to store in memory, and to indicate on the digital display (6), the maximum value of the torque (C) applied for a short given time, of the order of 5 seconds for example .
  • this memory is erased by the circuits (20) and the display (6) again indicates the programmed value (Cm).
  • the display In the event of resumption of tightening after a fairly short release time, and as soon as the torque exerted (C) exceeds the threshold (Co) of 15 Nm for example, the display is automatically switched by the circuit (18) to indicate the actual torque (C) and no longer the programmed value (Cm).
  • the power circuits (15) are such that, on the contrary, if a torque (C) greater than the threshold (Co) of 15 Nm has been applied, the power supply is maintained as long as the stops in use of the key remain less than 3 minutes.
  • this key can be used to transmit torques in both directions, when tightening or loosening.

Abstract

A torque wrench according to the invention has a rigid elongated body having a tool end adapted to be rotationally fixed to a part to which a predetermined desired torque is to be applied and an opposite handle end. Transducers including strain gauges connected between the tool end and the body generate an actual-value output corresponding to the actual torque being applied by the wrench to the part rotationally coupled to the tool end. A display connected to the transducers reads out torque and an input device generates a desired-value output corresponding to the desired torque to be applied by the wrench to the part rotationally coupled to the tool end. A first comparator connected to the transducer and input device compares the actual-value and desired-value signals and generates an alarm signal when the actual torque is substantially the same as the desired torque. In accordance with this invention a second comparator compared the actual torque with a relatively low threshold torque. A switch circuit connected between the display on one side and the transducer and second comparators on the other side feeds the desired-value signal to the display when the actual torque lies below the relatively low threshold torque and alternately feeds the actual-value signal to the display when the actual torque exceeds the threshold torque.

Description

La présente invention concerne une clé dynamométrique électronique. Cette clé comporte, de façon connue, une tête d'entraînement qui coopère avec l'élement à serrer et qui est liée à un corps allongé servant de poignée ainsi que de logement pour la partie électrique, celle-ci comprenant: un pont de mesure à jauges de contrainte pour la détermination du couple de serrage appliqué, des moyens d'alimentation électrique du pont de mesure et du restant des circuits, des moyens d'affichage numérique aptes à indiquer la valeur du couple de serrage, des moyens de comparaison du couple de serrage mesuré avec une valeur limite prescrite, et des moyens de signalisation qui sont déclenchés lorsque le couple de serrage appliqué et mesuré atteint ou dépasse la valeur limite prescrite.The present invention relates to an electronic torque wrench. This key comprises, in known manner, a drive head which cooperates with the element to be clamped and which is linked to an elongated body serving as a handle as well as housing for the electrical part, the latter comprising: a measuring bridge with strain gauges for determining the applied tightening torque, means for supplying power to the measuring bridge and the rest of the circuits, digital display means capable of indicating the value of the tightening torque, means for comparing the tightening torque measured with a prescribed limit value, and signaling means which are triggered when the applied and measured tightening torque reaches or exceeds the prescribed limit value.

Une clé dynamométrique de ce genre, décrite par exemple dans le brevet français N° 2 261 843, constitue un outil portatif autonome permettant de serrer un boulon avec un couple exactement défini. D'autres réalisations analogues comprennent un convertisseur analogique-numérique et des moyens d'affichage du type numérique, par exemple à diodes électroluminescentes, permettant une lecture directe de la valeur du couple de serrage appliqué - voir les brevets français N° 2 296 835 et N° 2 400 996.A torque wrench of this kind, described for example in French Patent No. 2,261,843, constitutes an autonomous portable tool making it possible to tighten a bolt with an exactly defined torque. Other similar embodiments include an analog-digital converter and display means of the digital type, for example with light-emitting diodes, allowing a direct reading of the value of the tightening torque applied - see French patents No. 2,296,835 and No. 2,400,996.

La présente invention vise à perfectionner ce genre de clé dynamométrique, notamment sur le plan de la commodité d'utilisation, et également du point de vue de la réduction de la consommation énergétique.The present invention aims to improve this kind of torque wrench, especially in terms of convenience of use, and also from the point of view of reducing energy consumption.

A cet effet, la clé dynamométrique électronique selon l'invention, est caractérisée en ce que ce sont les moyens d'affichage numérique qui sont utilisés alternativement pour indiquer la valeur du couple de serrage réel appliqué au moyen de la clé, et pour sélectionner et indiquer la valeur limite désirée de ce couple de serrage. De plus, des moyens sont prévus pour commuter automatiquement les moyens d'affichage, avec passage de l'indication de la valeur limite du couple de serrage à l'indication de sa valeur réelle mesurée, lorsque cette dernière valeur dépasse un seuil prédéterminé.To this end, the electronic torque wrench according to the invention is characterized in that it is the digital display means which are used alternately to indicate the value of the actual tightening torque applied by means of the key, and to select and indicate the desired limit value for this tightening torque. In addition, means are provided for automatically switching the display means, with passage from the indication of the limit value of the tightening torque to the indication of its actual measured value, when the latter value exceeds a predetermined threshold.

Les moyens d'affichage, qui de toute façon permettent de lire la valeur du couple de serrage réel appliqué à l'aide de la clé à l'élément del que boulon, sont ainsi mis à profit également dans l'invention pour «programmer» le couple de serrage désiré, avant l'utilisation de la clé. Cette opération préliminaire peut donc être effectuée de manière simple, rapide et précise. En outre, lors de l'utilisation de la clé, la valeur réelle du couple de serrage est affichée seulement à partir du moment où elle devient significative.The display means, which in any case make it possible to read the value of the actual tightening torque applied using the key to the element of the bolt, are thus also used in the invention to “program” the desired tightening torque, before using the key. This preliminary operation can therefore be carried out in a simple, rapid and precise manner. In addition, when using the wrench, the actual value of the tightening torque is displayed only from the moment it becomes significant.

Pour permettre la lecture et l'appréciation de la valeur réelle du couple de serrage exercé à l'aide de la clé, le passage inverse de l'indication de cette valeur réelle à l'indication de la valeur limite choisie n'est de préférence pas instantané lors de la disparition du couple de serrage. Au contraire, selon une caractéristique de l'invention, la clé dynamométrique comprend des moyens de mémorisation du couple de serrage maximal atteint, permettant aux moyens d'affichage d'indiquer encore la valeur de ce couple pendant une certaine durée après la fin du serrage les moyens d'affichage indiquant à nouveau la valeur limite prescritte après cette durée. De cette manière, une très brève interruption du serrage ne provoque pas le retour à l'affichage de la valeur limite du couple.To enable the actual value of the tightening torque exerted using the wrench to be read and appreciated, the reverse passage from the indication of this actual value to the indication of the chosen limit value is preferably not not instantaneous when the tightening torque disappears. On the contrary, according to a characteristic of the invention, the torque wrench comprises means for memorizing the maximum tightening torque reached, allowing the display means to still indicate the value of this torque for a certain period after the end of tightening. the display means again indicating the prescribed limit value after this period. In this way, a very brief interruption of the tightening does not cause the return to the display of the torque limit value.

Selon une forme de réalisation de l'invention, les moyens de comparaison sont agencés de manière à comparer d'une part de couple de serrage appliqué et mesuré avec une fraction prédéterminée de la valeur limite prescrite, et à comparer d'autre part le couple de serrage appliqué et mesuré avec cette valeur limite elle-même, les moyens de signalisation émettant un premier signal perceptible lorsque le couple de serrage appliqué et mesuré atteint ladite fraction prédéterminée, en émettant un second signal perceptible distinct du premier lorsque le couple de serrage appliqué et mesuré atteint la valeur limite elle-même. L'opérateur est ainsi averti par l'apparition du premier signal, qui peut être une alarme sonore, que le couple de serrage exercé atteint une fraction égale par exemple à environ 9/10 de la valeur limite prescrite. Le serrage peut donc être d'abord effectué rapidement, sans prêter attention à l'indication de couple donnée par les moyens d'affichage, jusqu'à lappro- che de la valeur limite. Seulement après déclenchement du premier signal d'alarme, l'opérateur termine le serrage plus lentement et en surveillant l'indication donnée par les moyens d'affichage, jusqu'à l'apparition du second signal, pouvant être une alarme lumineuse, qui indique que le couple limite est atteint et que le serrage ne doit pas être poursuivi.According to one embodiment of the invention, the comparison means are arranged so as to compare on the one hand the tightening torque applied and measured with a predetermined fraction of the prescribed limit value, and on the other hand to compare the torque of applied and measured tightening with this limit value itself, the signaling means emitting a first perceptible signal when the applied and measured tightening torque reaches said predetermined fraction, by emitting a second perceptible signal distinct from the first when the applied tightening torque and measured reaches the limit value itself. The operator is thus warned by the appearance of the first signal, which can be an audible alarm, that the tightening torque exerted reaches a fraction equal, for example, to approximately 9/10 of the prescribed limit value. Tightening can therefore first be carried out quickly, without paying attention to the torque indication given by the display means, until the limit value approaches. Only after triggering of the first alarm signal, the operator finishes tightening more slowly and by monitoring the indication given by the display means, until the appearance of the second signal, which may be a light alarm, which indicates that the limit torque is reached and that tightening must not be continued.

Selon une autre caractéristique de l'invention, les moyens d'alimentation électrique de la clé dynamométrique sont agencés de manière à maintenir l'alimentation des circuits pendant une durée minimale prédéterminée, et à couper automatiquement cette alimentation en cas de non utilisation de la clé au terme de cette durée fixée par exemple à 3 minutes après la mise en route. A l'inverse, l'alimentation électrique des circuits de la clé est maintenue aussi longtemps que l'arrêt d'utilisation de la clé reste inférieur à ladite durée prédéterminée, s'il a été appliqué un coupe de serrage supérieur au seuil déclenchant la commutation des moyens d'affichage.According to another characteristic of the invention, the electrical supply means of the torque wrench are arranged so as to maintain the supply of the circuits for a minimum predetermined duration, and to automatically cut this supply in the event of the key not being used at the end of this time, for example 3 minutes after start-up. Conversely, the electrical supply to the circuits of the key is maintained as long as the stopping of use of the key remains less than said predetermined duration, if a tightening cut has been applied above the threshold triggering the switching of display means.

De toute façon, l'invention sera mieux comprise à l'aide de la description qui suit, en référence au dessin schématique annexé représentant, à titre d'exemple non limitatif, une forme de réalisation de cette clé dynamométrique électronique:

  • fig. 1 est une vue en perspective d'une clé dynamométrique électronique avec moyens d'affichage du type numérique, conforme à l'invention;
  • fig. 2 est une vue en coupe longitudinale de la clé dynamométrique de fig. 1, montrant ses parties mécaniques et électriques internes;
  • fig. 3 en est une autre vue en coupe longitudinale passant par un plan perdendiculaire au plan de coupe de la fig. 2;
  • fig. 4 est un schéma synoptique des circuits de la partie électronique de cette clé dynamométrique.
In any case, the invention will be better understood with the aid of the following description, with reference to the appended schematic drawing representing, by way of nonlimiting example, an embodiment of this electronic torque wrench:
  • fig. 1 is a perspective view of an electronic torque wrench with display means of the digital type, according to the invention;
  • fig. 2 is a view in longitudinal section of the torque wrench in FIG. 1, showing its internal mechanical and electrical parts;
  • fig. 3 is another view in longitudinal section passing through a perdendicular plane to the section plane of FIG. 2;
  • fig. 4 is a block diagram of the circuits of the electronic part of this torque wrench.

La clé dynamométrique représentée sur les figures 1 à 3 comprend un corps tubulaire allongé (1), de section ovale, dont une extrémité est pourvue d'une partie (2) agencée de manière à recevoir une tête d'entraînement amovible (3), adaptée à l'élément à serrer tel que boulon, et dont l'extrémité opposée (4) est crantée et conformée en poignée de préhension. Dans sa région intermédiaire, le corps (1) de la clé comporte extérieurement une série de boutons-poussoirs ou de touches de commande (5), ainsi qu'un afficheur numérique (6) par exemple à cristaux liquides, servant alternativement à programmer le couple de serrage désiré et à indiquer la valeur du couple de serrage réellement appliqué. Lextrémité du corps (1) opposée à la tête d'entraînement (3) est obturée par un bouchon amovible (7) donnant accès à une pile électrique (8) qui fournit l'énergie nécessaire aux différents circuits de la clé dynamométrique.The torque wrench shown in Figures 1 to 3 comprises an elongated tubular body (1), of oval section, one end of which is provided with a part (2) arranged so as to receive a removable drive head (3), adapted to the element to be tightened such as a bolt, and the opposite end (4) of which is notched and shaped as a grip handle. In its intermediate region, the body (1) of the key externally comprises a series of push-buttons or control keys (5), as well as a digital display (6) for example with liquid crystals, used alternately to program the desired tightening torque and to indicate the value of the tightening torque actually applied. The end of the body (1) opposite the drive head (3) is closed by a removable plug (7) giving access to an electric battery (8) which supplies the energy necessary for the various circuits of the torque wrench.

Dans la forme de réalisation représentée, la partie (2) qui reçoit la tête d'entraînement (3) est prolongée par une queue (9) encastrée par deux de ses bords dans le corps tubulaire (1). ). Cette queue (9) est reliée, par l'intermédiaire d'un axe de liaison (10), à une plaquette allongée (11) s'étendant à l'intérieur du corps tubulaire (1 sur une grande partie de la longueur de ce dernier, et servant de support aux divers circuits électroniques (12-13) ainsi qu'à l'afficher numérique (6). Ces circuits électroniques permettent de traiter le signal électrique provenant des jauges de contrainte (14), collées sur une zone rétreinte (9a), subissant des flexions et reliant la queue (9) à la partie (2) recevant la tête d'entraînement (3). Le signal issu des jauges (14) est proportionnel au couple de serrage appliqué sur la poignée (4) et transmis par le corps tubulaire (1) à la tête d'entrainement (3) - voir notamment la fig. 2.In the embodiment shown, the part (2) which receives the drive head (3) is extended by a tail (9) embedded by two of its edges in the tubular body (1). ). This tail (9) is connected, by means of a connecting pin (10), to an elongated plate (11) extending inside the tubular body (1 over a large part of the length of this last, and serving as support for the various electronic circuits (12-13) as well as for the digital display (6). These electronic circuits make it possible to process the electrical signal coming from the strain gauges (14), stuck on a restricted area (9a), undergoing bending and connecting the tail (9) to the part (2) receiving the drive head (3). The signal from the gauges (14) is proportional to the tightening torque applied to the handle (4 ) and transmitted by the tubular body (1) to the drive head (3) - see in particular Fig. 2.

La fig. 4 représente, sous forme de schéma synoptique, les circuits essentiels de la partie électronique de cette clé dynamométrique.Fig. 4 shows, in the form of a block diagram, the essential circuits of the electronic part of this torque wrench.

A la pile électrique (8) sont associés des circuits d'alimentation (15) qui assurent:

  • - la mise en route de la clé, commandée par l'un des boutons-poussoirs (5),
  • - la génération d'une tension électrique stabilisée, qui alimente tous les autres circuits essentiels,
  • - le maintien de l'alimentation de ces circuits pendant une durée minimale prédéterminée, fixée par exemple à 3 minutes environ,
  • - la réactivation de cette alimentation à chaque nouvelle sollicitation de la clé.
Power circuits (15) are associated with the electric cell (8) which ensure:
  • - starting the key, controlled by one of the push-buttons (5),
  • - the generation of a stabilized electrical voltage, which supplies all the other essential circuits,
  • - maintaining the supply of these circuits for a predetermined minimum duration, fixed for example at around 3 minutes,
  • - reactivation of this power supply each time the key is pressed.

Le signal représentant le couple de serrage appliqué (C), issu des jauges de contrainte (14), est amené à des circuits d'amplification (16), où ce signal est d'abord amplifié. Les circuits d'amplification (16) comportent des moyens assurant le redressement et la commutation du signal inverse, lors du travail de la clé en sens inverse, de serrage ou de déserrage. De plus, ces circuits d'amplification assurent la commande de commutation de l'affichage, pour le passage automatique de l'indication de la valeur limite programmée du couple de serrage (Cm) à l'indication de la valeur mesurée, donc réelle du couple de serrage appliquée (C). Cette commutation se produit lorsque le couple appliqué au moyen de la clé dépasse un seuil (Co) fixé par exemple à 15 Nm.The signal representing the applied tightening torque (C), coming from the strain gauges (14), is supplied to amplification circuits (16), where this signal is first amplified. The amplification circuits (16) include means ensuring the rectification and switching of the reverse signal, when working the key in the opposite direction, tightening or loosening. In addition, these amplification circuits ensure the switching command of the display, for the automatic passage from the indication of the programmed limit value of the tightening torque (Cm) to the indication of the measured value, therefore real of the applied tightening torque (C). This switching occurs when the torque applied by means of the key exceeds a threshold (Co) fixed for example at 15 Nm.

Un circuit de commande de programmation (17) est associé, par exemple, à deux des boutons- poussois (5), pour permettre une programmation grossière rapide, puis une programmation fine plus lente de la valeur limite désirée du couple de serrage (Cm). Le circuit de commande de programmation (17) est relié à un circuit de mémorisation du couple et de commutation de l'affichage (18), relié à l'afficheur numérique (6) et permettant de commuter l'indication de cet afficheur (couple programmé Cm ou couple appliqué (C). A l'afficheur numérique (6) lui-même sont associés des circuits de conversion analogique-numerique, des circuits de mémorisation de l'affichage (19), et des circuits d'effacement de la mémoire (20).A programming control circuit (17) is associated, for example, with two of the push buttons (5), to allow rapid coarse programming, then slower fine programming of the desired limit value of the tightening torque (Cm) . The programming control circuit (17) is connected to a circuit for memorizing the torque and switching the display (18), connected to the digital display (6) and making it possible to switch the indication of this display (torque programmed Cm or applied torque (C). The digital display (6) itself is associated with analog-digital conversion circuits, display memory circuits (19), and circuits for erasing the memory (20).

Avantageusement, le circuit de commande de programmation (17) comporte des moyens, del qu'un condensateur, ou accumulateur, permettant de maintenir l'état sélectionné, à la valeur du couple limite (Cm), pendant un temps déterminé, de l'odre de deux à trois heures, que la clé ne soit plus utilisée ou que ses moyens d'alimentation électriques soient interrompus. Cela permet de maintenir la programmation prédéterminée en cas d'absence d'utilisation de la clé ou de remplacement de ses piles.Advantageously, the programming control circuit (17) comprises means, other than a capacitor, or accumulator, making it possible to maintain the selected state, at the value of the limit torque (Cm), for a determined time, from two to three hours, that the key is no longer used or that its means of electrical power are interrupted. This allows the predetermined programming to be maintained in the event of the key not being used or the batteries being replaced.

Des circuits de comparaison (21) assurent une comparaison de la valeur du couple de serrage appliqué et mesuré (C) avec al valeur limite du couple (Cm) prescrite à l'aide du circuit de commande de programmation (17). Les circuits de comparaison (21) assurent, aussi, une comparaison de la valeur du couple de serrage appliqué et mesuré (C) avec une fraction (k.Cm) de la valeur limite prescrite, le coefficient «k» étant, par exemple, égal à 0,9. Les circuits de comparaison (21) sont reliés à des moyens de signalisation (22), pouvant comprendre une alarme sonore (23) et une alarme lumineuse (24). Lorsque le couple de serrage (C) appliqué à l'aide de la clé atteint la fraction (k.Cm) de la valeur limite prescrite, soit dans l'exemple considéré les 9/10 de la valeur limite prescrite, l'alarme sonore (23) est déclenchée. Lorsque le couple de serrage (C) appliqué à l'aide de la clé atteint la valeur limite (Cm), l'alarme lumineuse (24) est déclenchée elle aussi.Comparison circuits (21) compare the value of the applied and measured tightening torque (C) with the torque limit value (Cm) prescribed using the programming control circuit (17). The comparison circuits (21) also ensure a comparison of the value of the applied and measured tightening torque (C) with a fraction (k.Cm) of the prescribed limit value, the coefficient “k” being, for example, equal to 0.9. The comparison circuits (21) are connected to signaling means (22), which may include an audible alarm (23) and a light alarm (24). When the tightening torque (C) applied using the key reaches the fraction (k.Cm) of the prescribed limit value, i.e. in the example considered 9/10 of the prescribed limit value, the audible alarm (23) is triggered. When the tightening torque (C) applied using the key reaches the limit value (Cm), the light alarm (24) is also triggered.

Les circuits de mémorisation (19) permettent de conserver en mémoire, et d'indiquer sur l'afficheur numérique (6), la valeur maximale du couple (C) appliqué pendant un temps donné bref, de l'odre de 5 secondes par exemple. Lorsque le serrage est interrompu pendant plus de 5 secondes, cette mémoire est effacée par les circuits (20) et l'afficheur (6) indique à nouveau la valeur programmée (Cm).The memory circuits (19) make it possible to store in memory, and to indicate on the digital display (6), the maximum value of the torque (C) applied for a short given time, of the order of 5 seconds for example . When the tightening is interrupted for more than 5 seconds, this memory is erased by the circuits (20) and the display (6) again indicates the programmed value (Cm).

En cas de reprise de serrage après un temps de rela- chement assez court, et dès que le couple exercé (C) dépasse le seuil (Co) de 15 Nm par exemple, l'afficheur est commuté automatiquement par le circuit (18) pour indiquer le couple réel (C) et non plus la valeur programmée (Cm).In the event of resumption of tightening after a fairly short release time, and as soon as the torque exerted (C) exceeds the threshold (Co) of 15 Nm for example, the display is automatically switched by the circuit (18) to indicate the actual torque (C) and no longer the programmed value (Cm).

Si la clé n'est pas utilisée après un temps de 3 minutes par exemple, l'alimentation est coupée par les circuits d'alimentation (15). Les fonctions de ces circuits (15) sont telles qu'au contraire, si un couple (C) supérieur au seuil (Co) de 15 Nm a été appliqué, l'alimentation est maintenue aussi longtemps que les arrêts d'utilisation de la clé restent inférieurs à 3 minutes.If the key is not used after 3 minutes, for example, the power is cut by the power circuits (15). The functions of these circuits (15) are such that, on the contrary, if a torque (C) greater than the threshold (Co) of 15 Nm has been applied, the power supply is maintained as long as the stops in use of the key remain less than 3 minutes.

Comme indiqué plus en avant, cette clé peut être utilisée pour transmettre des couples de rotation dans les deux sens, en serrage ou desserrage.As indicated above, this key can be used to transmit torques in both directions, when tightening or loosening.

Claims (10)

1. An electronic dynamometric key comprising a drive head (3) which co-operates with the element to be locked and which is connected to an elongate body (1) serving as a handle and as a housing for the electric part (12-13), comprising: a measuring bridge with strain gauges (14) for determining the applied locking force (C), electrical supply means (8) for the measuring bridge and the rest of the circuits, digital display means for indicating the value of the locking force (C), means (6) for comparing (21) the measured locking force (C) with a predetermined limiting value (Cm), and signalling means (22) which are triggered when the applied and measured locking force reaches or exceeds the predetermined limiting value (Cm), characterised in that the digital display means (6) are used alternately to indicate the value of the real locking force (C) applied by means of the key, and to select and indicate the required limiting value of this locking force (Cm), while means (16-18) are provided to switch the display means (16) automatically, passing from displaying the limiting value of the locking force (Cm) to displaying the true measured value (C), when the latter value exceeds a predetermined threshold (Co).
2. An electronic dynamometric key according to claim 1, characterised in that it comprises means for memorising (19) the maximum locking force (C) achieved, permitting the display means (6) to continue to indicate the value of this force (C) for a certain time after locking, the display means (6) signalling again the set limiting value (Cm) after this period.
3. An electronic dynamometric key according to either of claims 1 and 2, characterised in that the comparison means (21) are arranged so as to compare on the one hand the applied and measured locking force (C) with a predetermined fraction (k.Cm) of the set limiting value, and to compare on the other hand the applied and measured locking force (C) with this limiting value (Cm) itself, the signalling means (22) emitting a first signal which is perceptible when the applied and measured locking force (C) reaches the said predetermined fraction (k.Cm), and emitting a second perceptible signal distinct from the first when the applied and measured locking force (C) reaches the limiting value (Cm) itself.
4. An electronic dynamometric key according to claim 3, characterised in that the predetermined fraction (k.Cm) triggering the first perceptible signal is approximately 9/10 of the set limiting value of the locking force (Cm).
5. An electronic dynamometric key according to either of claims 3 and 4, characterised in thatthe signalling means (22) comprise a sound alarm (23) which is triggerend when the applied and measured locking force (C) reaches the predetermined fraction (k.Cm) of the set limiting value.
6. An electronic dynamometric key according to claim 5, characterised in that the signalling means (22) further comprise a light alarm (24) which is triggerend when the applied and measured locking force (C) reaches a set limiting value (Cm).
7. An electronic dynamometric key according to any one of claims 1 to 6, characterised in that the electric supply means (8-15) are arranged so as to maintain the supply to the circuits (12-13) for a predetermined minimum period, and to cut this supply automatically where the key is not used atthe end of this period.
8. An electronic dynamometric key according to all of claims 1-7, characterised in that the electric supply to its circuits is maintained whilst the key operation stop remains less than the said predetermined period, if a coupling force (C) greater than the threshold (Co) has been applied triggering the switching of the display means.
9. An electronic dynamometric key according to any one of claims 1 to 8, characterised in thatthe amplification circuits comprise rectification and switching means for the inverse signal operating when the key is used in the opposite direction.
10. An electronic dynamometric key according to any one of claims 1 to 9, characterised in that the programming control circuit (17) comprises means, such as a capacitor, or storage battery, for maintaining the selected logic state at the value of the force limit (Cm) for a set amount of time, should the key no longer be in use or the electrical supply means interrupted.
EP85420137A 1984-07-23 1985-07-22 Electronic torque wrench Expired EP0172120B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT85420137T ATE31262T1 (en) 1984-07-23 1985-07-22 ELECTRONIC TORQUE WRENCH.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8411917A FR2568010B1 (en) 1984-07-23 1984-07-23 ELECTRONIC DYNAMOMETRIC KEY
FR8411917 1984-07-23

Publications (2)

Publication Number Publication Date
EP0172120A1 EP0172120A1 (en) 1986-02-19
EP0172120B1 true EP0172120B1 (en) 1987-12-09

Family

ID=9306543

Family Applications (1)

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EP85420137A Expired EP0172120B1 (en) 1984-07-23 1985-07-22 Electronic torque wrench

Country Status (6)

Country Link
US (1) US4669319A (en)
EP (1) EP0172120B1 (en)
JP (1) JPS61109669A (en)
AT (1) ATE31262T1 (en)
DE (1) DE3561136D1 (en)
FR (1) FR2568010B1 (en)

Families Citing this family (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2615777B2 (en) * 1984-07-23 1989-10-06 Sam Outillage ELECTRONIC DYNAMOMETRIC KEY STRUCTURE
FR2615948B1 (en) * 1987-05-27 1989-10-27 Sam Outillage ELECTRONIC DYNAMOMETRIC KEY
US4982612A (en) * 1988-10-03 1991-01-08 Snap-On Tools Corporation Torque wrench with measurements independent of hand-hold position
US4987806A (en) * 1989-02-13 1991-01-29 Gse, Inc. Electronic control circuitry for a nutrunner
DE4039794A1 (en) * 1990-12-13 1992-06-17 Forst Saltus Werk TORQUE WRENCH
US5130700A (en) * 1991-03-04 1992-07-14 Snap-On Tools Corporation Electronic torque wrench and overshoot compensation circuit therefor
US5321506A (en) * 1991-06-14 1994-06-14 Usx Corporation Automatic screw-on pipe couplings
US5236053A (en) * 1992-05-15 1993-08-17 Aseptico, Incorporated Torque system
US5898598A (en) * 1996-10-25 1999-04-27 Cooper Technologies Company System and apparatus for a torque transducer with data processing capabilities
US5918201A (en) * 1996-10-25 1999-06-29 Gpx Corporation System and method for monitoring tool cycles
JPH10156743A (en) * 1996-12-05 1998-06-16 Tohnichi Mfg Co Ltd Torque driver
US6070506A (en) * 1998-07-20 2000-06-06 Snap-On Tools Company Ratchet head electronic torque wrench
US6463811B1 (en) 1999-04-28 2002-10-15 Snap-On Tools Company Bending beam torque wrench
DE10023174A1 (en) * 2000-05-11 2001-11-22 Bosch Gmbh Robert Electric hand tool, e.g. drill with speed control has automatic reset for adjuster, returning it to initial setting in accordance with an operational parameter
WO2003041914A2 (en) * 2001-11-14 2003-05-22 Snap-On Technologies, Inc. Electronic torque wrench
US6784799B2 (en) * 2002-08-07 2004-08-31 Chih-Ching Hsien Tension meter and wrench arrangement
US6910390B2 (en) * 2002-10-31 2005-06-28 Plastic Technologies, Inc. Hand held torque meter
US6796190B2 (en) * 2003-02-19 2004-09-28 Snap-On Incorporated Electronic torque wrench with flexible head
WO2005035201A2 (en) * 2003-10-03 2005-04-21 Snap-On Incorporated Ergonomic electronic torque wrench
DE102004003191A1 (en) * 2004-01-22 2005-08-11 Robert Bosch Gmbh Electric hand tool with storage option
US7699118B2 (en) * 2004-01-30 2010-04-20 Abas, Inc. System and method for controlling an impact tool
TWI240666B (en) * 2004-08-23 2005-10-01 Shiuan-Sen Shiau Electronic torque wrench
US6948380B1 (en) * 2004-08-23 2005-09-27 Stand Tools Enterprise Co., Ltd. Torque-indicating wrench
DE102005062883A1 (en) * 2005-12-29 2007-07-05 Robert Bosch Gmbh Power tool e.g. angle grinder has vibration reduction devices including auxiliary gauge that is connected by displacement unit, where vibration reduction devices are rigidly fastened at power tool
US20080127711A1 (en) * 2006-12-04 2008-06-05 Farag Tarek A Z Force and Torque Measurements with Calibration and Auto Scale
US8087330B2 (en) * 2006-12-05 2012-01-03 Chih-Ching Hsieh Hand tool with warning effect
US20080127786A1 (en) * 2006-12-05 2008-06-05 Chih-Ching Hsieh Hand tool with earphone
US8201464B2 (en) * 2008-09-02 2012-06-19 Easco Hand Tools Inc Electronic torque wrench with a manual input device
US8215258B2 (en) * 2008-11-21 2012-07-10 Charles R. Givens Alarmed chuck wrench
SE532720C2 (en) 2008-12-22 2010-03-23 Atlas Copco Tools Ab Handheld nut puller with manually controlled power control
US7841245B1 (en) * 2009-06-09 2010-11-30 Hsin-Nien Chen Electronic torque wrench
US8714057B2 (en) 2010-01-04 2014-05-06 Apex Brands, Inc. Ratcheting device for an electronic torque wrench
US8413525B1 (en) * 2012-06-11 2013-04-09 Thru Tubing Solutions, Inc. Portable torque measurement and notification system and method of using same
US8528423B1 (en) 2012-06-11 2013-09-10 Thru Tubing Solutions, Inc. Portable torque measurement and notification system and method of using same
US8549932B1 (en) 2012-06-11 2013-10-08 Thru Tubing Solutions, Inc. Portable torque measurement and notification system and method of using same
US9395257B2 (en) * 2013-05-10 2016-07-19 Snap-On Incorporated Electronic torque tool with integrated real-time clock
US11453105B2 (en) 2016-09-13 2022-09-27 Milwaukee Electric Tool Corporation Powered ratcheting torque wrench
US10625405B2 (en) 2016-09-13 2020-04-21 Milwaukee Electric Tool Corporation Powered ratcheting torque wrench
TWI671166B (en) * 2018-12-06 2019-09-11 優鋼機械股份有限公司 Body of electronic torque wrench

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3895517A (en) * 1974-01-14 1975-07-22 Jo Line Tools Electronic torque wrench
US4397196A (en) * 1979-08-29 1983-08-09 Lemelson Jerome H Electronic tool and method
FR2497347A1 (en) * 1980-12-31 1982-07-02 Sicame Sa Electronic dynamometer key for electric cable repair - has strain gauge and comparator providing signal when max. required torque is attained
DE3228086A1 (en) * 1982-07-28 1984-02-16 Dipl.-Ing. Peter Pohl GmbH, 4010 Hilden TORQUE WRENCH WITH ELECTRONIC MEASUREMENT, EVALUATION AND DISPLAY
FR2542657B1 (en) * 1983-03-17 1985-11-29 Facom DYNAMOMETRIC TIGHTENING APPARATUS
US4558601A (en) * 1984-01-06 1985-12-17 J. S. Technology, Inc. Digital indicating torque wrench

Also Published As

Publication number Publication date
JPS61109669A (en) 1986-05-28
DE3561136D1 (en) 1988-01-21
ATE31262T1 (en) 1987-12-15
US4669319A (en) 1987-06-02
EP0172120A1 (en) 1986-02-19
FR2568010B1 (en) 1987-05-15
FR2568010A1 (en) 1986-01-24

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