EP0296912A1 - Method and apparatus to improve the discharge regime of an electric arc between two electrodes by interposing a high resistive insulating element, shock-wave generator using such a method and apparatus, particularly for hydraulic lithotrypsie - Google Patents

Method and apparatus to improve the discharge regime of an electric arc between two electrodes by interposing a high resistive insulating element, shock-wave generator using such a method and apparatus, particularly for hydraulic lithotrypsie Download PDF

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Publication number
EP0296912A1
EP0296912A1 EP88401364A EP88401364A EP0296912A1 EP 0296912 A1 EP0296912 A1 EP 0296912A1 EP 88401364 A EP88401364 A EP 88401364A EP 88401364 A EP88401364 A EP 88401364A EP 0296912 A1 EP0296912 A1 EP 0296912A1
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EP
European Patent Office
Prior art keywords
electrodes
insulating element
arc
resistance
electric arc
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EP88401364A
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German (de)
French (fr)
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EP0296912B1 (en
Inventor
Dominique Cathignol
Bernard Lacruche
Jean-Louis Mestas
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Institut National de la Sante et de la Recherche Medicale INSERM
Technomed International SA
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Institut National de la Sante et de la Recherche Medicale INSERM
Technomed International SA
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Priority to AT88401364T priority Critical patent/ATE68636T1/en
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    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K15/00—Acoustics not otherwise provided for
    • G10K15/04—Sound-producing devices
    • G10K15/06—Sound-producing devices using electric discharge
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
    • H01T14/00—Spark gaps not provided for in groups H01T2/00 - H01T13/00

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  • the invention essentially relates to a method and a device for improving the discharge regime of an electric arc produced between two electrodes, by interposing an insulating element with high resistance at least between the electrodes, and an apparatus for generating waves. shock using such a method or device, especially for hydraulic lithotrypsia.
  • Electrodes 12 and 13 are made of highly conductive material such as copper or brass and are mounted on an insulator 26 which is pivotally supported by means of a device 11a, 11b, so as to adjust the spacing between them (see column 4, lines 42 to 53 and column 8, lines 40 to 47).
  • Document FR-A-2 247 195 also describes a similar device in which the liquid consists of water (page 3, lines 23-24).
  • the discharge or electric arc is produced between the electrodes by the sudden discharge of a capacitor 11, by the closing of a high voltage switch (see FIG. 2b) .
  • the circuit between the electrodes includes a capacitor, as well as an associated self-inductance. It has been observed that the discharge of the capacitor is of the damped oscillatory type. In other words, the capacitor will discharge and then recharge in the opposite direction at a lower voltage than the initial voltage, which is very high and of the order of 15,000 to 20,000 V, then again recharge in the direct direction until 'upon exhaustion of the charges contained in the capacitor.
  • the main object of the present invention is therefore to solve the new technical problem consisting in providing a solution making it possible to deliver suddenly or in a relatively short time most of the energy stored by the charge of the capacitor of the discharge circuit. between two electrodes.
  • the present invention also aims to solve the new technical problem consisting in the supply of a solu tion allowing the production of a substantially spherical initial pressure wave.
  • the present invention also aims to solve the new technical problem of providing a solution to reduce the wear of the electrodes.
  • a method for improving the discharge regime of an electric arc produced in a fluid medium, in particular of low resistance, such as water, between at least two electrodes generating such an arc characterized in that the resistance to the passage of the electric arc is increased at least between the electrodes.
  • an insulating element with high resistance is interposed between the electrodes generating the arc.
  • This insulating element thus advantageously constitutes an obstacle to the direct passage of the arc between the electrodes.
  • the resistance of the insulating element is chosen so that this resistance induces a discharge of the arc of the critical damped type.
  • a shape of the insulating element such that the initial shock or pressure wave created by the generation of the arc is substantially spherical.
  • the shape of the insulating element is essentially spherical.
  • the present invention also provides a device for improving the discharge regime of an electric arc produced in a fluid medium, in particular of low resistance, such as water, between at least two electrodes generating such a arc, characterized in that it comprises means to increase the resistance to the passage of the electric arc at least between the electrodes.
  • these means for increasing the resistance to the passage of the electric arc comprise an insulating element with high resistance interposed between the electrodes generating the arc.
  • the resistance and the shape of the insulating element can be defined as previously mentioned in relation to the process.
  • the insulating element comprises two grooves or cavities for positioning the two electrodes, so as to result in easy positioning of the electrodes generating the arc at a predetermined distance known in advance.
  • a currently preferred use of the method and of the device according to the invention relates to devices for generating shock waves, and in particular those which comprise a truncated ellipsoidal reflector of the Rieber type of US Pat. No. 2,559,227.
  • the insulating element is integral with a support rod mounted inside the ellipsoid.
  • This support rod can be fixedly attached to the wall of the ellipsoid or be retractably mounted, while the insulating element is advantageously provided to be removable relative to the support rod.
  • FIG. 1 there is shown schematically, by the general reference number 10, a truncated ellipsoidal reflector of the type described in US Patent Rieber 2,559,227, which is provided with at least two electrodes 12 , 14, here diametrically opposite, contributing to the focal point symbolized by the reference F of the truncated ellipsoidal reflector 10.
  • the second focal point of the ellipsoid is arranged outside the truncated ellipsoidal reflector and it is to this second focal point that will coincide a target which is to be destroyed, as described at length in the US Rieber patent, or in document FR-2 247 195.
  • the electrodes 12, 14 are mounted on electrode-carrying elements 16, 18, also electrically conductive.
  • One of the electrodes, for example the electrode 12, is connected to ground or rather to the earth symbolized by the reference T.
  • the other electrode for example the electrode 14, is part of an electric circuit symbolized by the general reference CE which is used to generate a very high voltage between the electrodes 10 and 12 when this is desired to create a discharge or electric arc between the electrodes 10 and 12.
  • the cavity defined inside the truncated ellipsoidal reflector 10 is filled with a fluid, preferably a liquid, more preferably water. The generation of this electric arc will therefore create pressure or shock waves at the internal focal point F of the truncated ellipsoidal reflector 10 which will be focused on the second focal point where the target to be destroyed is arranged, as is known per se.
  • This electric circuit CE can for example comprise, from the electrode 14, a conventional resistance R followed by a Self S then by a switch I. Then, the conductor CO is subdivided into conductor CO1 and CO2. The conductor CO2 then again leads to a Self S ′ and then to the capacitor C which is designed to be able to withstand very high voltage loads up to 15,000 to 20,000 V for example, this capacitor C then being connected to earth T.
  • the CO1 conductor leads to another switch I ′ which is then connected to a power generation source P, such as a battery, possibly with interposition between the switch I ′ and the power generator P of a transformer capable of transforming the low voltage of the power generator P into a very high voltage, for example of the order of 15,000 to 20,000 V. Then, the power generator P also leads to earth T.
  • a power generation source P such as a battery
  • the energy dissipation curve P obtained by such a conventional discharge from the capacitor C is shown in FIG. 2b and it can be seen that the energy stored in the capacitor is gradually dissipated over time.
  • the pressure or shock waves are generated by the sudden passage of the current or the arc between the electrodes and will be progressively weaker or of lower energy (P) and there will therefore be a succession of waves thus generated increasingly low energy.
  • the present invention aims to solve this new technical problem posed by the inventors.
  • means are provided identified by the general reference number 30 to increase the resistance to the passage of the electric arc at least between the electrodes 12, 14.
  • these means 30 increasing the resistance to the passage of the electric arc comprise an insulating element 32 with high resistance interposed between the electrodes 12, 14 generating the arc.
  • high resistance is meant that this resistance of the insulating element is much greater than the resistance of the fluid medium filling the cavity 20 of the truncated ellipsoidal reflector 10. This resistance ratio between that of the insulating element and that of the fluid medium filling the ellipsoidal reflector 10 is at least equal to 100, more preferably equal to 1000 or several times 1000.
  • the resistance of the insulating element is equal to at least several times 1000 the critical resistance of the discharge circuit (usually a few Ohms).
  • the insulating element has a resistance such that this resistance value induces a discharge from the critical damped arc, and therefore also from the capacitor C, this discharge curve being shown at Figure 3a.
  • the insulating element has a generally substantially spherical shape, which makes it possible to generate a substantially spherical initial pressure shock wave.
  • the center of the sphere constituting the insulating element 32 it can be seen that it is advantageous for the center of the sphere constituting the insulating element 32 to coincide substantially or exactly with the internal focal point F of the truncated ellipsoidal reflector 10.
  • the element insulator 32 preferably of substantially spherical shape, has two grooves 34, 36 or cavities for the positioning of the electrodes 12, 14, as shown in FIG. 1 so that at the front stop of the electrodes 34, 36 against the bottom of the cavities 34, 36, of the insulating element 32 the electrodes are located concurrently and above all symmetrically with respect to the focal point F of the truncated ellipsoidal reflector 10.
  • the electrodes 12, 14 when the electrodes 12, 14 are in abutment against the bottom cavities 34, 36, these electrodes 12, 14 are permanently arranged exactly symmetrically with respect to the focal point F of the ellipsoid defined by the truncated ellipsoidal reflector 10.
  • the auron shock waves t a wavefront which is centered exactly at the focal point F.
  • the insulating element 32 By the essentially spherical shape of the insulating element 32, and by its insulating nature, it is understood that the insulating element 32 will constitute an obstacle to the passage of the current lines which will be forced to bypass this obstacle.
  • the dimension of the element 32 is chosen so as to obtain the critical discharge experimentally (see FIG. 3a).
  • the current lines generated between the electrodes 12, 14 symbolized in dotted lines by the reference number A will also be essentially of spherical shape and therefore will generate waves. exactly centered on focal point F.
  • the discharge regime of the capacitor C which is thus obtained according to the invention of the critical damped type, the dissipation of the energy will be in accordance with the curve of FIG. 3b and one will therefore obtain a very high pressure wave, essentially unique, which will result in a better efficiency of destruction of the targets.
  • devices for advancing the electrodes are provided. Such devices are described for example in EP-A-124 686 but it is preferred to use advancement devices described in the previous applications of the applicants not yet published, FR-86 01 380 or FR-86 06 318. Still preferably, advancement devices of the type described in previous requests, in particular request 86 06 318, will be used, modified so that the drive is done by means of a pneumatic means with friction system so as to maintain permanently the front end of the electrodes 12, 14 in contact against the insulating element 32 at the bottom of the cavities 34, 36. This makes it possible to permanently maintain the front end of the electrodes 12, 14 exactly symmetrically with respect to the focal point F, therefore at exactly equal distance from focal point F.
  • the insulating element 32 is in practice supported by a support means in the form of a rod 40 which can be mounted inside on the wall 11 of the truncated ellipsoidal reflector 10.
  • This support means 40 can be fixed in a non-removable manner or be mounted dismountable and possibly be provided retractable or telescopic.
  • the material constituting this rod 40 is advantageously an insulating material and its diameter is as small as possible so as not to substantially disturb the shock waves generated on its side.

Abstract

L'invention concerne un procédé et un dispositif pour améliorer le régime de décharge d'un arc électrique produit entre deux électrodes.Ce dispositif est caractérisé en ce qu'il comprend des moyens (30) pour augmenter la résistance au passage de l'arc élec­trique (A) au moins entre les électrodes (12, 14), de préférence constitués par un élément isolant (32) qui est encore de préférence de forme sensiblement sphérique.Grâce à l'invention, on obtient un régime de décharge de l'arc qui est de type amorti critique. Ce procédé et ce disposi­tif sont utilisés de préférence dans un appareil de génération d'ondes de choc pour la lithotrypsie hydraulique.The invention relates to a method and a device for improving the discharge rate of an electric arc produced between two electrodes. This device is characterized in that it comprises means (30) for increasing the resistance to the passage of the arc electric (A) at least between the electrodes (12, 14), preferably constituted by an insulating element (32) which is still preferably of substantially spherical shape. arc which is of the critically damped type. This method and this device are preferably used in an apparatus for generating shock waves for hydraulic lithotrypsy.

Description

L'invention concerne essentiellement un procédé et un dispositif pour améliorer le régime de décharge d'un arc électrique produit entre deux électrodes, par interposition d'un élément isolant à résistance élevée au moins entre les électrodes, et un appareil de génération d'ondes de choc utilisant un tel procédé ou dispositif, notamment pour la lithotrypsie hydraulique.The invention essentially relates to a method and a device for improving the discharge regime of an electric arc produced between two electrodes, by interposing an insulating element with high resistance at least between the electrodes, and an apparatus for generating waves. shock using such a method or device, especially for hydraulic lithotrypsia.

Il est connu par le brevet US Rieber n° 2 559 227 un appareil de génération d'ondes de choc de fréquence élevée, compre­nant un réflecteur ellipsoïdal tronqué 80 dans lequel sont générées des ondes de choc par décharge ou arc électrique entre deux élec­trodes concourantes au premier foyer de l'ellipsoïde, de manière à détruire une cible disposée au deuxième foyer de l'ellipsoïde, se trouvant à l'extérieur du réflecteur tronqué 80 (voir figure 3 et colonne 7, ligne 51, colonne 9, ligne 30).It is known from US patent Rieber n ° 2,559,227 an apparatus for generating shock waves of high frequency, comprising a truncated ellipsoidal reflector 80 in which shock waves are generated by discharge or electric arc between two electrodes concurrent in the first focal point of the ellipsoid, so as to destroy a target disposed at the second focal point of the ellipsoid, located outside of the truncated reflector 80 (see FIG. 3 and column 7, line 51, column 9, line 30).

Des électrodes 12 et 13 sont réalisées en matériau hautement conducteur tel que du cuivre ou du laiton et sont montées sur un isolateur 26 qui est supporté de manière pivotante à l'aide d'un dispositif 11a, 11b, de manière à régler l'espacement entre celles-ci (voir colonne 4, lignes 42 à 53 et colonne 8, lignes 40 à 47).Electrodes 12 and 13 are made of highly conductive material such as copper or brass and are mounted on an insulator 26 which is pivotally supported by means of a device 11a, 11b, so as to adjust the spacing between them (see column 4, lines 42 to 53 and column 8, lines 40 to 47).

Le document FR-A-2 247 195 décrit également un appareil similaire dans lequel le liquide est constitué par de l'eau (page 3, lignes 23-24).Document FR-A-2 247 195 also describes a similar device in which the liquid consists of water (page 3, lines 23-24).

Lors de l'emploi de l'appareil Rieber ou appareil simi­laire, on produit la décharge ou arc électrique, entre les électrodes grâce à la brusque décharge d'un condensateur 11, par la fermeture d'un interrupteur haute tension (voir figure 2b). Selon l'appareil Rieber, le circuit entre les électrodes, comprend un condensateur, ainsi qu'une self-inductance associée. On a pu observer que la décharge du condensateur est de type oscillatoire amorti. Autrement dit, le condensateur va se décharger puis se recharger en sens inverse à une tension plus basse que la tension initiale, qui est très élevée et de l'ordre de 15 000 à 20 000 V, puis de nouveau se recharger en sens direct jusqu'à épuisement des charges contenues dans le condensateur.When using the Rieber device or similar device, the discharge or electric arc is produced between the electrodes by the sudden discharge of a capacitor 11, by the closing of a high voltage switch (see FIG. 2b) . According to the Rieber device, the circuit between the electrodes includes a capacitor, as well as an associated self-inductance. It has been observed that the discharge of the capacitor is of the damped oscillatory type. In other words, the capacitor will discharge and then recharge in the opposite direction at a lower voltage than the initial voltage, which is very high and of the order of 15,000 to 20,000 V, then again recharge in the direct direction until 'upon exhaustion of the charges contained in the capacitor.

Simultanément, il s'établit un arc électrique entre les deux électrodes dont le courant sera aussi, par voie de consé­quence, de type oscillatoire amorti.Simultaneously, an electric arc is established between the two electrodes, the current of which will also, consequently, of the damped oscillatory type.

On sait que le courant ou arc électrique qui s'établit entre les deux électrodes vaporise le liquide, en particulier l'eau, et crée par la même occasion une onde de pression ou onde de choc utilisable pour la destruction d'une cible.It is known that the current or electric arc which is established between the two electrodes vaporizes the liquid, in particular water, and at the same time creates a pressure wave or shock wave usable for the destruction of a target.

On comprend que plus la vaporisation du liquide, en particulier de l'eau, sera rapide, plus l'onde de pression sera forte et plus son temps de montée sera bref.It will be understood that the faster the vaporization of the liquid, in particular of the water, the stronger the pressure wave and the shorter its rise time.

Ainsi, pour qu'une quantité importante de liquide, en particulier d'eau, soit vaporisée, il sera nécessaire de délivrer soudainement une énergie importante.Thus, for a large quantity of liquid, in particular water, to be vaporized, it will be necessary to suddenly deliver a large amount of energy.

Tous les dispositifs actuellement connus aboutissent à des décharges qui sont toutes de type oscillatoire amorti, type qui est représenté sur la figure 2a avec l'énergie dissipée dans le temps (figure 2b), ces figures étant explicitées plus en détail plus loin, cette énergie étant dissipée progressivement au cours du temps.All the devices currently known result in discharges which are all of the damped oscillatory type, which type is represented in FIG. 2a with the energy dissipated over time (FIG. 2b), these figures being explained in more detail below, this energy being gradually dissipated over time.

La présente invention a donc pour but principal de résoudre le nouveau problème technique consistant en la fourniture d'une solution permettant de délivrer soudainement ou en un temps relativement bref la plus grande partie de l'énergie emmagasinée par la charge du condensateur du circuit de décharge entre deux électrodes.The main object of the present invention is therefore to solve the new technical problem consisting in providing a solution making it possible to deliver suddenly or in a relatively short time most of the energy stored by the charge of the capacitor of the discharge circuit. between two electrodes.

La présente invention a encore pour but de résoudre le nouveau problème technique consistant en la fourniture d'une solu­ tion permettant la production d'une onde de pression initiale sensiblement sphérique.The present invention also aims to solve the new technical problem consisting in the supply of a solu tion allowing the production of a substantially spherical initial pressure wave.

La présente invention a encore pour but de résoudre le nouveau problème technique consistant en la fourniture d'une solu­tion permettant de réduire l'usure des électrodes.The present invention also aims to solve the new technical problem of providing a solution to reduce the wear of the electrodes.

Tous ces nouveaux problèmes techniques sont résolus pour la première fois par la présente invention de manière satis­faisante.All these new technical problems are solved for the first time by the present invention in a satisfactory manner.

Ainsi, selon la présente invention, on fournit, selon un premier aspect, un procédé pour améliorer le régime de décharge d'un arc électrique produit dans un milieu fluide, notamment de faible résistance, tel que l'eau, entre au moins deux électrodes génératrices d'un tel arc, caractérisé en ce qu'on augmente la résistance au passage de l'arc électrique au moins entre les élec­trodes.Thus, according to the present invention, there is provided, according to a first aspect, a method for improving the discharge regime of an electric arc produced in a fluid medium, in particular of low resistance, such as water, between at least two electrodes generating such an arc, characterized in that the resistance to the passage of the electric arc is increased at least between the electrodes.

Selon un mode de réalisation particulièrement préféré du procédé selon l'invention, pour augmenter cette résistance, on interpose entre les électrodes génératrices de l'arc un élément isolant à résistance élevée. Cet élément isolant constitue ainsi avantageusement un obstacle au passage direct de l'arc entre les électrodes.According to a particularly preferred embodiment of the method according to the invention, to increase this resistance, an insulating element with high resistance is interposed between the electrodes generating the arc. This insulating element thus advantageously constitutes an obstacle to the direct passage of the arc between the electrodes.

Selon une autre caractéristique avantageuse du procédé de l'invention, on choisit la résistance de l'élément isolant de telle sorte que cette résistance induise une décharge de l'arc de type amorti critique.According to another advantageous characteristic of the method of the invention, the resistance of the insulating element is chosen so that this resistance induces a discharge of the arc of the critical damped type.

Selon encore une autre caractéristique du procédé de l'invention, on prévoit une forme de l'élément isolant telle que l'onde de choc ou de pression initiale créée par la génération de l'arc soit sensiblement sphérique. De préférence, la forme de l'élément isolant est essentiellement sphérique.According to yet another characteristic of the method of the invention, provision is made for a shape of the insulating element such that the initial shock or pressure wave created by the generation of the arc is substantially spherical. Preferably, the shape of the insulating element is essentially spherical.

Selon un deuxième aspect, la présente invention fournit également un dispositif pour améliorer le régime de décharge d'un arc électrique produit dans un milieu fluide, notamment de faible résistance, tel que l'eau, entre au moins deux électrodes généra­trices d'un tel arc, caractérisé en ce qu'il comprend des moyens pour augmenter la résistance au passage de l'arc électrique au moins entre les électrodes.According to a second aspect, the present invention also provides a device for improving the discharge regime of an electric arc produced in a fluid medium, in particular of low resistance, such as water, between at least two electrodes generating such a arc, characterized in that it comprises means to increase the resistance to the passage of the electric arc at least between the electrodes.

Selon un mode de réalisation particulièrement préféré, ces moyens pour augmenter la résistance au passage de l'arc élec­trique comprennent un élément isolant à résistance élevée interposé entre les électrodes génératrices de l'arc. La résistance et la forme de l'élément isolant peuvent être définies comme précédemment mentionné en relation avec le procédé.According to a particularly preferred embodiment, these means for increasing the resistance to the passage of the electric arc comprise an insulating element with high resistance interposed between the electrodes generating the arc. The resistance and the shape of the insulating element can be defined as previously mentioned in relation to the process.

Par ailleurs, selon une autre caractéristique avanta­geuse, l'élément isolant comprend deux saignées ou cavités de posi­tionnement des deux électrodes, de manière à aboutir à un posi­tionnement aisé des électrodes génératrices de l'arc à une distance prédéterminée connue à l'avance.Furthermore, according to another advantageous characteristic, the insulating element comprises two grooves or cavities for positioning the two electrodes, so as to result in easy positioning of the electrodes generating the arc at a predetermined distance known in advance.

Une utilisation actuellement préférée du procédé et du dispositif selon l'invention concerne les appareils de génération d'ondes de choc, et en particulier ceux qui comprennent un réflec­teur ellipsoïdal tronqué du type Rieber du brevet US 2 559 227.A currently preferred use of the method and of the device according to the invention relates to devices for generating shock waves, and in particular those which comprise a truncated ellipsoidal reflector of the Rieber type of US Pat. No. 2,559,227.

Dans ce cas, il est clair que la présence des deux saignées ou cavités précitées dans l'élément isolant va permettre de positionner les électrodes génératrices de l'arc de telle sorte qu'elles soient concourantes et disposées symétriquement par rapport au foyer interne du réflecteur ellipsoïdal tronqué.In this case, it is clear that the presence of the two aforementioned grooves or cavities in the insulating element will make it possible to position the electrodes generating the arc so that they are concurrent and arranged symmetrically with respect to the internal focus of the reflector truncated ellipsoidal.

Selon une autre caractéristique avantageuse, l'élément isolant est solidaire d'une tige support montée à l'intérieur de l'ellipsoïde. Cette tige support peut être fixée solidairement à la paroi de l'ellipsoïde ou être montée de manière escamotable, tandis que l'élément isolant est avantageusement prévu pour être démon­table relativement à la tige support.According to another advantageous characteristic, the insulating element is integral with a support rod mounted inside the ellipsoid. This support rod can be fixedly attached to the wall of the ellipsoid or be retractably mounted, while the insulating element is advantageously provided to be removable relative to the support rod.

On comprend ainsi que l'on obtient tous les avantages techniques précédemment énoncés.It is thus understood that one obtains all the technical advantages previously stated.

D'autres buts, caractéristiques et avantages de l'invention apparaîtront également à l'homme de l'art au vu de la description explicative qui va suivre faite en référence aux dessins annexés représentant un mode de réalisation actuellement préféré de l'invention donné simplement à titre d'illustration et qui ne saurait donc en aucune façon limiter la portée de l'inven­tion. Dans les dessins :

  • - la figure 1 est une vue en coupe partielle schéma­tique d'un réflecteur ellipsoïdal tronqué du type décrit dans le brevet US Rieber 2 559 227, selon un plan de coupe transversal passant par les électrodes et le foyer interne du réflecteur tronqué ellipsoïdal, avec le circuit de charge du condensateur et de décharge de celui-ci entre les électrodes, représenté schémati­quement ;
  • - la figure 2a représente la courbe classique de tension du condensateur selon Rieber en fonction du temps obtenue lors de la décharge de celui-ci dont on voit qu'elle est de type oscillatoire amorti ;
  • - la figure 2b représente l'énergie dissipée, P = RI², en fonction du temps lors de la décharge du condensateur selon Rieber, ce qui permet d'observer que cette énergie est progressivement dissipée au cours du temps ; et résultant de la courbe de tension de la figure 2a.
  • - la figure 3a représente la courbe de tension du condensateur, obtenue avec l'invention, en fonction du temps, lors de la décharge du condensateur, on peut y observer que cette courbe de décharge obtenue selon l'invention est de type amorti critique ; et
  • - la figure 3b représente la courbe de dissipation d'énergie en fonction du temps, obtenue selon l'invention, et résultant de la courbe de tension de la figure 3a.
Other objects, characteristics and advantages of the invention will also appear to those skilled in the art in the light of the explanatory description which will follow made with reference to the appended drawings representing a currently preferred embodiment of the invention given simply for illustration and which therefore cannot in any way limit the scope of the invention. In the drawings:
  • - Figure 1 is a schematic partial sectional view of a truncated ellipsoidal reflector of the type described in US Patent Rieber 2,559,227, along a transverse sectional plane passing through the electrodes and the internal focus of the truncated ellipsoidal reflector, with the circuit for charging the capacitor and discharging it between the electrodes, shown diagrammatically;
  • - Figure 2a shows the classic voltage curve of the capacitor according to Rieber as a function of the time obtained during the discharge thereof which we see that it is of the damped oscillatory type;
  • - Figure 2b represents the dissipated energy, P = RI², as a function of time during the discharge of the capacitor according to Rieber, which makes it possible to observe that this energy is gradually dissipated over time; and resulting from the voltage curve of Figure 2a.
  • - Figure 3a shows the voltage curve of the capacitor, obtained with the invention, as a function of time, during the discharge of the capacitor, it can be observed that this discharge curve obtained according to the invention is of the critical damped type; and
  • - Figure 3b shows the curve of energy dissipation as a function of time, obtained according to the invention, and resulting from the voltage curve of Figure 3a.

En référence à la figure 1, on a représenté de manière schématique, par le numéro de référence général 10, un réflecteur ellipsoïdal tronqué du type de celui décrit dans le brevet US Rieber 2 559 227, qui est pourvu d'au moins deux électrodes 12, 14, ici diamétralement opposées, concourantes au foyer symbolisé par la référence F du réflecteur ellipsoïdal tronqué 10. Le deuxième foyer de l'ellipsoïde est disposé à l'extérieur du réflecteur ellipsoïdal tronqué et c'est à ce second foyer que l'on fera coïncider une cible qui est à détruire, comme cela est longuement décrit dans le brevet US Rieber, ou encore dans le document FR-2 247 195.Referring to Figure 1, there is shown schematically, by the general reference number 10, a truncated ellipsoidal reflector of the type described in US Patent Rieber 2,559,227, which is provided with at least two electrodes 12 , 14, here diametrically opposite, contributing to the focal point symbolized by the reference F of the truncated ellipsoidal reflector 10. The second focal point of the ellipsoid is arranged outside the truncated ellipsoidal reflector and it is to this second focal point that will coincide a target which is to be destroyed, as described at length in the US Rieber patent, or in document FR-2 247 195.

Généralement, les électrodes 12, 14 sont montées sur des éléments porte-électrodes 16, 18, également électriquement conducteurs. L'une des électrodes, par exemple l'électrode 12, est reliée à la masse ou plutôt à la terre symbolisée par le repère T.Generally, the electrodes 12, 14 are mounted on electrode-carrying elements 16, 18, also electrically conductive. One of the electrodes, for example the electrode 12, is connected to ground or rather to the earth symbolized by the reference T.

L'autre électrode, par exemple l'électrode 14, fait partie d'un circuit électrique symbolisé par le repère général CE qui sert à générer une tension très élevée entre les électrodes 10 et 12 lorsque cela est désiré pour créer une décharge ou arc élec­trique entre les électrodes 10 et 12. En outre, la cavité définie à l'intérieur du réflecteur ellipsoïdal tronqué 10 est remplie par un fluide, de préférence un liquide, encore de préférence de l'eau. La génération de cet arc électrique va donc créer des ondes de pression ou de choc au foyer interne F du réflecteur ellipsoïdal tronqué 10 qui vont être focalisées au second foyer où est disposée la cible à détruire, comme cela est connu en soi.The other electrode, for example the electrode 14, is part of an electric circuit symbolized by the general reference CE which is used to generate a very high voltage between the electrodes 10 and 12 when this is desired to create a discharge or electric arc between the electrodes 10 and 12. In addition, the cavity defined inside the truncated ellipsoidal reflector 10 is filled with a fluid, preferably a liquid, more preferably water. The generation of this electric arc will therefore create pressure or shock waves at the internal focal point F of the truncated ellipsoidal reflector 10 which will be focused on the second focal point where the target to be destroyed is arranged, as is known per se.

Ce circuit électrique CE peut par exemple comprendre, depuis l'électrode 14, une résistance classique R suivie d'une Self S puis d'un interrupteur I. Ensuite, le conducteur CO se subdivise en conducteur CO₁ et CO₂. Le conducteur CO₂ aboutit ensuite encore à une Self S′ puis au condensateur C qui est prévu pour pouvoir supporter des charges de tension très élevées jusqu'à 15 000 à 20 000 V par exemple, ce condensateur C étant ensuite relié à la terre T. Le conducteur CO₁ aboutit quant à lui à un autre interrup­teur I′ qui est relié ensuite à une source de génération de puis­sance P, telle qu'une batterie, éventuellement avec interposition entre l'interrupteur I′ et le générateur de puissance P d'un trans­formateur capable de transformer le faible voltage du générateur de puissance P en un voltage très élevé, par exemple de l'ordre de 15 000 à 20 000 V. Ensuite, le générateur de puissance P aboutit également à la terre T.This electric circuit CE can for example comprise, from the electrode 14, a conventional resistance R followed by a Self S then by a switch I. Then, the conductor CO is subdivided into conductor CO₁ and CO₂. The conductor CO₂ then again leads to a Self S ′ and then to the capacitor C which is designed to be able to withstand very high voltage loads up to 15,000 to 20,000 V for example, this capacitor C then being connected to earth T. The CO₁ conductor leads to another switch I ′ which is then connected to a power generation source P, such as a battery, possibly with interposition between the switch I ′ and the power generator P of a transformer capable of transforming the low voltage of the power generator P into a very high voltage, for example of the order of 15,000 to 20,000 V. Then, the power generator P also leads to earth T.

On comprend ainsi que lorsque l'interrupteur I est ouvert, comme représenté, et l'interrupteur I′ est fermé, on va charger le condensateur C grâce au générateur de puissance P. Ensuite, lorsque l'on ouvre l'interrupteur I′, comme représenté, et que l'on ferme l'interrupteur I, alors le condensateur C va se décharger par l'intermédiaire des électrodes 10, 12, le circuit CO-CO₂-T étant ainsi fermé.It is thus understood that when the switch I is open, as shown, and the switch I ′ is closed, we will charge the capacitor C thanks to the power generator P. Then, when the switch I ′ is opened, as shown, and the switch I is closed, then the capacitor C will discharge via the electrodes 10, 12, the circuit CO-CO₂- T thus being closed.

Dans le cas classique, tel que celui décrit dans le brevet US Rieber précité ou dans le document FR-A-2 247 195, on obtient dans ce cas la génération d'un arc électrique du type oscillatoire amorti en raison de la courbe de décharge du condensa­teur qui est elle-même du type oscillatoire amorti et qui est représentée à la figure 2a. Ceci est dû au fait que le condensateur C va se décharger puis se recharger en sens inverse à une tension plus basse que la tension initiale qui est de l'ordre de 15 000 à 20 000 V, puis de nouveau se recharger en sens direct jusqu'à épui­sement des charges contenues dans le condensateur. De ce fait, le courant constituant l'arc électrique entre les électrodes sera aussi du type oscillatoire amorti et aura donc une courbe au cours du temps similaire à celle de la figure 2a.In the conventional case, such as that described in the aforementioned US patent Rieber or in the document FR-A-2 247 195, one obtains in this case the generation of an electric arc of the oscillatory type damped due to the curve of discharge of the capacitor which is itself of the damped oscillatory type and which is represented in FIG. 2a. This is due to the fact that the capacitor C will discharge and then recharge in the opposite direction at a lower voltage than the initial voltage which is of the order of 15,000 to 20,000 V, then again recharge in the direct direction until 'upon exhaustion of the charges contained in the capacitor. Therefore, the current constituting the electric arc between the electrodes will also be of the damped oscillatory type and will therefore have a curve over time similar to that of FIG. 2a.

La courbe de dissipation d'énergie P obtenue par une telle décharge classique du condensateur C est représentée à la figure 2b et on voit que l'énergie emmagasinée dans le condensateur est progressivement dissipée au cours du temps. Ainsi, les ondes de pression ou de choc sont générées par le brusque passage du courant ou de l'arc entre les électrodes et seront progressivement plus faibles ou de plus faible énergie (P) et il y aura donc une succession d'ondes ainsi générées d'énergie de plus en plus faible.The energy dissipation curve P obtained by such a conventional discharge from the capacitor C is shown in FIG. 2b and it can be seen that the energy stored in the capacitor is gradually dissipated over time. Thus, the pressure or shock waves are generated by the sudden passage of the current or the arc between the electrodes and will be progressively weaker or of lower energy (P) and there will therefore be a succession of waves thus generated increasingly low energy.

Or, pour détruire la cible qui se trouve au second foyer du réflecteur ellipsoïdal tronqué 10, il est nécessaire de générer sensiblement instantanément une onde de choc de pression la plus élevée possible, donc d'énergie la plus élevée possible. Il est donc nécessaire de délivrer soudainement et dans le laps de temps le plus court possible l'énergie la plus grande possible.However, to destroy the target which is at the second focal point of the truncated ellipsoidal reflector 10, it is necessary to generate substantially instantly the highest possible pressure shock wave, therefore the highest possible energy. It is therefore necessary to deliver suddenly and in the shortest possible time the greatest possible energy.

La présente invention, comme mentionné précédemment, a donc pour but de résoudre ce nouveau problème technique posé par les inventeurs.The present invention, as mentioned above, therefore aims to solve this new technical problem posed by the inventors.

Pour ce faire, selon l'invention, on prévoit des moyens repérés par le numéro de référence général 30 pour augmenter la résistance au passage de l'arc électrique au moins entre les élec­trodes 12, 14.To do this, according to the invention, means are provided identified by the general reference number 30 to increase the resistance to the passage of the electric arc at least between the electrodes 12, 14.

Selon un mode de réalisation actuellement préféré, ces moyens 30 augmentant la résistance au passage de l'arc électrique comprennent un élément isolant 32 à résistance élevée interposé entre les électrodes 12, 14 génératrices de l'arc.According to a currently preferred embodiment, these means 30 increasing the resistance to the passage of the electric arc comprise an insulating element 32 with high resistance interposed between the electrodes 12, 14 generating the arc.

Par la mention "résistance élevée", on entend que cette résistance de l'élément isolant est bien plus grande que la résis­tance du milieu fluide remplissant la cavité 20 du réflecteur ellipsoïdal tronqué 10. Ce rapport de résistance entre celle de l'élément isolant et celle du milieu fluide remplissant le réflec­teur ellipsoïdal 10 est au moins égal à 100, encore de préférence égal à 1 000 ou plusieurs fois 1000.By the term "high resistance" is meant that this resistance of the insulating element is much greater than the resistance of the fluid medium filling the cavity 20 of the truncated ellipsoidal reflector 10. This resistance ratio between that of the insulating element and that of the fluid medium filling the ellipsoidal reflector 10 is at least equal to 100, more preferably equal to 1000 or several times 1000.

Il est avantageux que la résistance de I'élément isolant soit égale à au moins plusieurs fois 1000 la résistance critique du circuit de décharge (habituellement de quelques Ohms).It is advantageous that the resistance of the insulating element is equal to at least several times 1000 the critical resistance of the discharge circuit (usually a few Ohms).

Selon une autre caractéristique particulièrement avan­tageuse de l'invention, l'élément isolant présente une résistance telle que cette valeur de résistance induise une décharge de l'arc de type amorti critique, et donc également du condensateur C, cette courbe de décharge étant représentée à la figure 3a.According to another particularly advantageous characteristic of the invention, the insulating element has a resistance such that this resistance value induces a discharge from the critical damped arc, and therefore also from the capacitor C, this discharge curve being shown at Figure 3a.

On a pu observer que ce régime de décharge amorti cri­tique du condensateur C est obtenu avec de nombreux matériaux isolants. Selon l'invention, on utilise de manière très pratique simplement de la céramique, la céramique présentant une résistance habituellement égale à 100 K Ohms.It has been observed that this critical damped discharge regime of the capacitor C is obtained with numerous insulating materials. According to the invention, very simply ceramic is used, the ceramic having a resistance usually equal to 100 K Ohms.

Selon une autre caractéristique particulièrement avan­tageuse du dispositif selon l'invention, l'élément isolant présente une forme générale sensiblement sphérique, ce qui permet de générer une onde de choc de pression initiale sensiblement sphérique. Dans le cas de l'utilisation du dispositif selon l'invention dans un appareil de génération d'ondes de choc, comme représenté à la figure 1, en particulier du type à réflecteur ellipsoïdal tronqué 10, on conçoit qu'il est avantageux que le centre de la sphère constituant l'élément isolant 32 coïncide sensiblement ou exacte­ment avec le foyer interne F du réflecteur ellipsoïdal tronqué 10. En outre, il est avantageux selon l'invention que l'élément isolant 32, de préférence de forme sensiblement sphérique, comporte deux saignées 34, 36 ou cavités pour le positionnement des électrodes 12, 14, comme représenté à la figure 1 de telle sorte qu'en butée frontale des électrodes 34, 36 contre le fond des cavités 34, 36, de l'élément isolant 32 les électrodes sont situées concourantes et surtout symétriquement par rapport au foyer F du réflecteur ellipsoïdal tronqué 10. On comprend que par cette structure particulière, lorsque les électrodes 12, 14 sont en butée contre le fond des cavités 34, 36, ces électrodes 12, 14 sont en permanence disposées exactement symétriquement par rapport au foyer F de l'ellipsoïde défini par le réflecteur ellipsoïdal tronqué 10. Ainsi, les ondes de choc auront un front d'onde qui est centré exactement au foyer F.According to another particularly advantageous characteristic of the device according to the invention, the insulating element has a generally substantially spherical shape, which makes it possible to generate a substantially spherical initial pressure shock wave. In the case of the use of the device according to the invention in an apparatus for generating shock waves, as shown in FIG. 1, in particular of the type with truncated ellipsoidal reflector 10, it can be seen that it is advantageous for the center of the sphere constituting the insulating element 32 to coincide substantially or exactly with the internal focal point F of the truncated ellipsoidal reflector 10. Furthermore, it is advantageous according to the invention that the element insulator 32, preferably of substantially spherical shape, has two grooves 34, 36 or cavities for the positioning of the electrodes 12, 14, as shown in FIG. 1 so that at the front stop of the electrodes 34, 36 against the bottom of the cavities 34, 36, of the insulating element 32 the electrodes are located concurrently and above all symmetrically with respect to the focal point F of the truncated ellipsoidal reflector 10. It is understood that by this particular structure, when the electrodes 12, 14 are in abutment against the bottom cavities 34, 36, these electrodes 12, 14 are permanently arranged exactly symmetrically with respect to the focal point F of the ellipsoid defined by the truncated ellipsoidal reflector 10. Thus, the auron shock waves t a wavefront which is centered exactly at the focal point F.

Par la forme essentiellement sphérique de l'élément isolant 32, et par son caractère isolant, on comprend que l'élément isolant 32 va constituer un obstacle au passage des lignes de cou­rant qui vont ête obligées de contourner cet obstacle.By the essentially spherical shape of the insulating element 32, and by its insulating nature, it is understood that the insulating element 32 will constitute an obstacle to the passage of the current lines which will be forced to bypass this obstacle.

Ainsi, la dimension de l'élément 32 est choisie de façon à obtenir expérimentalement la décharge critique (voir figure 3a).Thus, the dimension of the element 32 is chosen so as to obtain the critical discharge experimentally (see FIG. 3a).

En outre, par l'adoption de la forme essentiellement sphérique de l'élément isolant 32, les lignes de courant générées entre les électrodes 12, 14 symbolisées en pointillé par le numéro de référence A seront également essentiellement de forme sphérique et généreront donc des ondes de choc exactement centrées sur le foyer F.In addition, by adopting the essentially spherical shape of the insulating element 32, the current lines generated between the electrodes 12, 14 symbolized in dotted lines by the reference number A will also be essentially of spherical shape and therefore will generate waves. exactly centered on focal point F.

Grâce au régime de décharge du condensateur C qui est ainsi obtenu selon l'invention du type amorti critique, la dissipa­tion de l'énergie sera conforme à la courbe de la figure 3b et on obtiendra donc une onde de pression très élevée, essentiellement unique, ce qui aboutira à une meilleure efficacité de destruction des cibles.Thanks to the discharge regime of the capacitor C which is thus obtained according to the invention of the critical damped type, the dissipation of the energy will be in accordance with the curve of FIG. 3b and one will therefore obtain a very high pressure wave, essentially unique, which will result in a better efficiency of destruction of the targets.

En outre, grâce à cette décharge obtenue essentiel­lement en une seule fois, on va aboutir à une réduction inattendue de l'usure des différents éléments, en particulier des électrodes, du condensateur C, et de l'interrupteur haute tension I qui supporte mal les courants et tensions inverses.In addition, thanks to this discharge obtained essentially in one go, there will be an unexpected reduction in the wear of the various elements, in particular of the electrodes, of the capacitor C, and of the high voltage switch I which cannot withstand the reverse currents and voltages.

Par ailleurs, l'usure des électrodes étant par ailleurs inévitable et due aux générations successives d'arcs électriques entre elles, cette usure étant par ailleurs inégale entre les électrodes, il y a lieu de repositionner correctement les élec­trodes de manière qu'elles soient exactement disposées symétrique­ment par rapport au foyer F.In addition, the wear of the electrodes being moreover inevitable and due to the successive generations of electric arcs between them, this wear being moreover unequal between the electrodes, it is necessary to correctly reposition the electrodes so that they are exactly arranged symmetrically with respect to the focus F.

Généralement, on prévoit des dispositifs d'avancement des électrodes. De tels dispositifs sont décrits par exemple dans EP-A-124 686 mais on préfère utiliser des dispositifs d'avancement décrits dans les demandes antérieures des demanderesses non encore publiées, FR-86 01 380 ou FR-86 06 318. Encore de préférence, on utilisera des dispositifs d'avancement du type décrit dans des demandes précédentes, notamment la demande 86 06 318, modifiés de façon que l'entraînement se fasse par l'intermédiaire d'un moyen pneumatique avec système à friction de façon à maintenir en perma­nence l'extrémité frontale des électrodes 12, 14 en contact contre l'élément isolant 32 en fond des cavités 34, 36. Ceci permet de maintenir en permanence l'extrémité frontale des électrodes 12, 14 exactement symétriquement par rapport au foyer F, donc à distance exactement égale du foyer F.Generally, devices for advancing the electrodes are provided. Such devices are described for example in EP-A-124 686 but it is preferred to use advancement devices described in the previous applications of the applicants not yet published, FR-86 01 380 or FR-86 06 318. Still preferably, advancement devices of the type described in previous requests, in particular request 86 06 318, will be used, modified so that the drive is done by means of a pneumatic means with friction system so as to maintain permanently the front end of the electrodes 12, 14 in contact against the insulating element 32 at the bottom of the cavities 34, 36. This makes it possible to permanently maintain the front end of the electrodes 12, 14 exactly symmetrically with respect to the focal point F, therefore at exactly equal distance from focal point F.

On obtiendra ainsi une amélioration supplémentaire du fonctionnement de l'appareil et donc à une amélioration de destruc­tion des cibles.This will give an additional improvement in the operation of the device and therefore an improvement in the destruction of targets.

L'élément isolant 32 est en pratique supporté par un moyen support sous forme d'une tige 40 qui peut être montée à l'intérieur sur la paroi 11 du réflecteur ellipsoïdal tronqué 10. Ce moyen support 40 peut être fixé de manière non démontable ou être monté démontable et éventuellement être prévu rétractable ou télescopique. Le matériau constituant cette tige 40 est avantageu­sement un matériau isolant et son diamètre est le plus réduit possible de manière à ne pas perturber sensiblement les ondes de choc générées de son côté.The insulating element 32 is in practice supported by a support means in the form of a rod 40 which can be mounted inside on the wall 11 of the truncated ellipsoidal reflector 10. This support means 40 can be fixed in a non-removable manner or be mounted dismountable and possibly be provided retractable or telescopic. The material constituting this rod 40 is advantageously an insulating material and its diameter is as small as possible so as not to substantially disturb the shock waves generated on its side.

On comprend que le dispositif ainsi décrit permet de mettre en oeuvre le procédé précédemment décrit qui n'est donc pas répété ici. Il en est de même du fonctionnement qui résulte claire­ment de la description précédente qui contient déjà des explica­tions de fonctionnement explicites pour un homme du métier.It is understood that the device thus described makes it possible to implement the method described above which is therefore not repeated here. The same applies to the operation which clearly results from the preceding description which already contains explanations of operation which are explicit for a person skilled in the art.

L'invention comprend naturellement dans sa portée tous les moyens constituant des équivalents techniques des moyens décrits et représentés dans les figures 1, 3a, 3b qui font partie intégrante de l'invention.The invention naturally includes within its scope all the means constituting technical equivalents of the means described and shown in Figures 1, 3a, 3b which are an integral part of the invention.

Claims (11)

1. Procédé pour améliorer le régime de décharge d'un arc électrique produit dans un milieu fluide, notamment de faible résistance, tel que l'eau, entre au moins deux électrodes (12, 14) génératrices d'un tel arc, caractérisé en ce qu'on augmente la résistance au passage de l'arc électrique au moins entre les élec­trodes (12, 14).1. Method for improving the discharge regime of an electric arc produced in a fluid medium, in particular of low resistance, such as water, between at least two electrodes (12, 14) generating such an arc, characterized in this increases the resistance to the passage of the electric arc at least between the electrodes (12, 14). 2. Procédé selon la revendication 1, caractérisé en ce qu'on interpose un élément isolant (32) à résistance élevée, entre les électrodes (12, 14) génératrices de l'arc.2. Method according to claim 1, characterized in that an insulating element (32) with high resistance is interposed between the electrodes (12, 14) generating the arc. 3. Procédé selon la revendication 2, caractérisé en ce qu'on choisit la résistance de l'élément isolant (32) de telle sorte que cette résistance induise une décharge de l'arc de type amorti critique.3. Method according to claim 2, characterized in that the resistance of the insulating element (32) is chosen so that this resistance induces a discharge of the arc of the critical damped type. 4. Procédé selon l'une des revendications 1 à 3, caractérisé en ce qu'on prévoit une forme de l'élément isolant telle que la forme de l'arc soit sensiblement sphérique, de préfé­rence cette forme de l'élément isolant (32) étant sensiblement sphérique.4. Method according to one of claims 1 to 3, characterized in that a shape of the insulating element is provided such that the shape of the arc is substantially spherical, preferably this shape of the insulating element (32 ) being substantially spherical. 5. Dispositif pour améliorer le régime de décharge d'un arc électrique produit dans un milieu fluide, notamment de faible résistance, tel que l'eau, entre au moins deux électrodes (12, 14) génératrices d'un tel arc, caractérisé en ce qu'il comprend des moyens (30) pour augmenter la résistance au passage de l'arc élec­trique (A) au moins entre les électrodes (12, 14).5. Device for improving the discharge regime of an electric arc produced in a fluid medium, in particular of low resistance, such as water, between at least two electrodes (12, 14) generating such an arc, characterized in what it includes means (30) for increasing the resistance to the passage of the electric arc (A) at least between the electrodes (12, 14). 6. Dispositif selon la revendication 5, caractérisé en ce que les moyens précités (30) pour augmenter la résistance au passage de l'arc électrique (A) comprennent un élément isolant (32) à résistance élevée interposé entre les électrodes (12, 14) géné­ratrices de l'arc.6. Device according to claim 5, characterized in that the aforementioned means (30) for increasing the resistance to the passage of the electric arc (A) comprise an insulating element (32) with high resistance interposed between the electrodes (12, 14 ) generators of the arc. 7. Dispositif selon la revendication 6, caractérisé en ce que la résistance de l'élément isolant (32) est choisie de telle sorte qu'elle induise une décharge de l'arc de type amorti critique.7. Device according to claim 6, characterized in that the resistance of the insulating element (32) is chosen so that it induces a discharge of the arc of the critical damped type. 8. Dispositif selon l'une des revendications 5 à 7, caractérisé en ce que l'élément isolant (32) présente une forme sensiblement sphérique.8. Device according to one of claims 5 to 7, characterized in that the insulating element (32) has a substantially spherical shape. 9. Dispositif selon l'une des revendications 5 à 8, caractérisé en ce que l'élément isolant (32) comprend deux saignées (34, 36) ou cavités de positionnement des électrodes (12, 14) de sorte que lorsque la partie frontale des électrodes (12, 14) est en butée contre le fond des saignées (34, 36), les électrodes (12, 14) sont situées concourantes et symétriquement par rapport à un point foyer F où doit être centré l'arc (A).9. Device according to one of claims 5 to 8, characterized in that the insulating element (32) comprises two grooves (34, 36) or cavities for positioning the electrodes (12, 14) so that when the front part electrodes (12, 14) abuts against the bottom of the grooves (34, 36), the electrodes (12, 14) are located concurrently and symmetrically with respect to a focal point F where the arc (A) must be centered . 10. Appareil de génération d'onde de choc par généra­tion d'un arc électrique entre deux électrodes, caractérisé en ce qu'il comprend un dispositif tel que décrit selon l'une quelconque des revendications 5 à 9, ou en ce qu'il utilise le procédé tel que défini selon l'une quelconque des revendications 1 à 4.10. Apparatus for generating a shock wave by generating an electric arc between two electrodes, characterized in that it comprises a device as described according to any one of claims 5 to 9, or in that it uses the method as defined according to any one of claims 1 to 4. 11. Appareil de génération d'onde de choc selon la revendication 10, caractérisé en ce qu'il comprend un réflecteur ellipsoïdal tronqué (10), l'élément isolant (32) précité est avan­tageusement solidaire d'un moyen support (40) formant tige monté à l'intérieur dudit réflecteur ellipsoïdal tronqué (10), de préfé­rence le centre de l'élément isolant (32) coïncide avec le foyer interne (F) du réflecteur ellipsoïdal.11. shock wave generation apparatus according to claim 10, characterized in that it comprises a truncated ellipsoidal reflector (10), the aforementioned insulating element (32) is advantageously secured to a support means (40) forming rod mounted inside said truncated ellipsoidal reflector (10), preferably the center of the insulating element (32) coincides with the internal focus (F) of the ellipsoidal reflector.
EP88401364A 1987-06-16 1988-06-06 Method and apparatus to improve the discharge regime of an electric arc between two electrodes by interposing a high resistive insulating element, shock-wave generator using such a method and apparatus, particularly for hydraulic lithotrypsie Expired - Lifetime EP0296912B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT88401364T ATE68636T1 (en) 1987-06-16 1988-06-06 METHOD AND DEVICE FOR IMPROVING THE DISCHARGE PROCESS OF AN ELECTRIC ARC BETWEEN TWO ELECTRODES BY INTERMEDIATELY AN INSULATING ELEMENT OF HIGH RESISTANCE AND IMPACT GENERATOR USING SUCH METHOD AND SUCH DEVICE, PARTICULARLY FOR HYDRAULIC LITHO TRYPSIA.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8708400 1987-06-16
FR8708400A FR2616977B1 (en) 1987-06-16 1987-06-16 METHOD AND DEVICE FOR IMPROVING THE DISCHARGE REGIME OF AN ELECTRIC ARC PRODUCED BETWEEN TWO ELECTRODES, BY INTERPOSING AN INSULATING ELEMENT WITH HIGH RESISTANCE AT LEAST BETWEEN THE ELECTRODES, AND APPARATUS FOR GENERATING SHOCK WAVE USING SUCH A METHOD OR DEVICE , ESPECIALLY FOR HYDRAULIC LITHOTRYPSY

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EP0296912A1 true EP0296912A1 (en) 1988-12-28
EP0296912B1 EP0296912B1 (en) 1991-10-16

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US (1) US4962753A (en)
EP (1) EP0296912B1 (en)
JP (1) JPS6420838A (en)
AT (1) ATE68636T1 (en)
DE (2) DE296912T1 (en)
FR (1) FR2616977B1 (en)
IL (1) IL86734A0 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4020770A1 (en) * 1989-06-30 1991-01-03 Technomed Int Sa METHOD AND DEVICE FOR SIGNIFICANT IMPROVEMENT OF REPRODUCIBILITY AND EFFECTIVENESS IN THE ELECTRICAL DISCHARGE OF A CAPACITY BETWEEN TWO ELECTRODES PRODUCED PRESSURE WAVES BY ZWISCHENFUEGUNG an electrically conductive liquid BETWEEN THE PADS, AND PLANT FOR PRODUCTION OF SHOCK WAVES USING SAID METHOD OR SUCH A DEVICE, ESPECIALLY FOR HYDRAULIC LITHOTRIPSY
EP0427956A1 (en) * 1989-11-15 1991-05-22 Dornier Medizintechnik Gmbh Improvement of the ignition characteristics of underwater spark gaps
US5251614A (en) * 1989-06-30 1993-10-12 Technomed International Method and device interposing an electrically conductive liquid between electrodes and shockwave apparatus for method and device
CN106130532A (en) * 2016-06-24 2016-11-16 中国科学院上海光学精密机械研究所 Electrion laser triggered switch

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US1960142A (en) * 1932-08-03 1934-05-22 Paniagua Marie-Louise Ysabe De Spark gap for electric oscillations generators
US2559227A (en) * 1947-05-24 1951-07-03 Interval Instr Inc Shock wave generator

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US3222567A (en) * 1962-03-09 1965-12-07 Sylvania Electric Prod Projection lamp
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FR2612345A1 (en) * 1987-03-09 1988-09-16 Technomed Int Sa METHOD AND DEVICE FOR DETECTING AND CORRECTING THE POSITION OF ELECTRODES ESPECIALLY USED IN IMPACT WAVE GENERATING APPARATUSES USING A FOCAL POINT FIXED PROBE FINGER PARTICULARLY CONSISTING OF A CABLE ROD

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US1960142A (en) * 1932-08-03 1934-05-22 Paniagua Marie-Louise Ysabe De Spark gap for electric oscillations generators
US2559227A (en) * 1947-05-24 1951-07-03 Interval Instr Inc Shock wave generator

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4020770A1 (en) * 1989-06-30 1991-01-03 Technomed Int Sa METHOD AND DEVICE FOR SIGNIFICANT IMPROVEMENT OF REPRODUCIBILITY AND EFFECTIVENESS IN THE ELECTRICAL DISCHARGE OF A CAPACITY BETWEEN TWO ELECTRODES PRODUCED PRESSURE WAVES BY ZWISCHENFUEGUNG an electrically conductive liquid BETWEEN THE PADS, AND PLANT FOR PRODUCTION OF SHOCK WAVES USING SAID METHOD OR SUCH A DEVICE, ESPECIALLY FOR HYDRAULIC LITHOTRIPSY
FR2649252A1 (en) * 1989-06-30 1991-01-04 Technomed Int Sa METHOD AND DEVICE FOR DISCHARGING AN ELECTRIC ARC IN AN ELECTRICALLY CONDUCTIVE LIQUID AND APPLICATION TO THE LITHOTRYPTOR
US5251614A (en) * 1989-06-30 1993-10-12 Technomed International Method and device interposing an electrically conductive liquid between electrodes and shockwave apparatus for method and device
DE4020770C3 (en) * 1989-06-30 2003-08-21 Technomed Medical Systems Vaul Method and device for significantly improving the reproducibility and effectiveness of the pressure waves generated in the electrical discharge of a capacitance between two electrodes by interposing an electrically conductive liquid between the electrodes, and use of the device using such a method, in particular for hydraulic lithotripsy
EP0427956A1 (en) * 1989-11-15 1991-05-22 Dornier Medizintechnik Gmbh Improvement of the ignition characteristics of underwater spark gaps
CN106130532A (en) * 2016-06-24 2016-11-16 中国科学院上海光学精密机械研究所 Electrion laser triggered switch
CN106130532B (en) * 2016-06-24 2019-01-29 中国科学院上海光学精密机械研究所 Electrion laser triggered switch

Also Published As

Publication number Publication date
JPS6420838A (en) 1989-01-24
ATE68636T1 (en) 1991-11-15
US4962753A (en) 1990-10-16
IL86734A0 (en) 1988-11-30
FR2616977A1 (en) 1988-12-23
EP0296912B1 (en) 1991-10-16
DE3865545D1 (en) 1991-11-21
DE296912T1 (en) 1989-04-20
FR2616977B1 (en) 1992-04-03

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