WO2005037487A1 - Centring clamp with modular locking mechanism - Google Patents

Centring clamp with modular locking mechanism Download PDF

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Publication number
WO2005037487A1
WO2005037487A1 PCT/FR2004/002583 FR2004002583W WO2005037487A1 WO 2005037487 A1 WO2005037487 A1 WO 2005037487A1 FR 2004002583 W FR2004002583 W FR 2004002583W WO 2005037487 A1 WO2005037487 A1 WO 2005037487A1
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WO
WIPO (PCT)
Prior art keywords
support
jaws
lens
ophthalmic lens
centering
Prior art date
Application number
PCT/FR2004/002583
Other languages
French (fr)
Inventor
Laurent Guillermin
Michel Nauche
Original Assignee
Essilor International (Compagnie Generale D'optique)
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Essilor International (Compagnie Generale D'optique) filed Critical Essilor International (Compagnie Generale D'optique)
Publication of WO2005037487A1 publication Critical patent/WO2005037487A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B13/00—Machines or devices designed for grinding or polishing optical surfaces on lenses or surfaces of similar shape on other work; Accessories therefor
    • B24B13/005—Blocking means, chucks or the like; Alignment devices
    • B24B13/0055—Positioning of lenses; Marking of lenses
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B9/00—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor
    • B24B9/02—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground
    • B24B9/06—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground of non-metallic inorganic material, e.g. stone, ceramics, porcelain
    • B24B9/08—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground of non-metallic inorganic material, e.g. stone, ceramics, porcelain of glass
    • B24B9/14—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground of non-metallic inorganic material, e.g. stone, ceramics, porcelain of glass of optical work, e.g. lenses, prisms
    • B24B9/146—Accessories, e.g. lens mounting devices

Definitions

  • the invention relates to the field of equipment intended for the treatment of ophthalmic lenses. It relates more particularly to a centering-blocking device adapted to determine the position of an optical center in the case of a single focal lens, the position of one of the optical centers in the case of bifocal or trifocal lenses, and also adapted to determine some of the marks that the manufacturer usually displays on the surface of progressive lenses.
  • the centering-blocking device is further adapted to determine by calculation a point on the surface of the lens defining the location at which a drive pin will be placed.
  • Central blockers are common devices in the field of optics. They are involved in the manufacturing process of a pair of glasses, just before machining the ophthalmic lenses to adapt them to the shape of the selected glasses frame.
  • Document EP 1 080 835 discloses a centralizing and blocking device provided for manual determination of the optical center.
  • This centralizer-blocker comprises a single piece forming the support of the ophthalmic lens and comprising three feet, the lens being arranged so that a pattern projected through it makes it possible to determine on a screen the desired optical center.
  • the user of the machine acts by manually moving the lens on its support until he sees a pattern on the screen indicating that the optical center of the lens is aligned with an axis of the machine. In this position, an arm is adapted to deposit the glans in a position determined by calculation.
  • Document EP 1 057 589 also discloses a centering and blocking device comprising an automatic centering device for the ophthalmic lens.
  • This centering and blocking device comprises retractable supports intended to support the lens, a concentric clamping device intended to take over from the retractable supports for fixing the lens in a predetermined position.
  • This assembly is then automatically moved relative to an optical device similar to that described above while software allows the determination of the optical center of the lens. The glans is then placed similarly to that described above.
  • These automatic centering and blocking devices are simple and effective to use but cannot be used for certain types of glass such as tinted glasses or high power glasses.
  • the object of the invention is to improve this type of equipment by providing a centralizing and blocking device suitable for any type of ophthalmic lens.
  • the invention relates to a centering-blocking device, intended to allow the installation of a drive pin at a location determined by calculation of an ophthalmic lens, comprising a support plate adapted to allow light to pass through and to support the ophthalmic lens; a light source adapted to produce a light beam passing through the ophthalmic lens when it is in place on the support plate; as well as an image acquisition device for capturing the light beam after it has passed through the ophthalmic lens; the centering and blocking device being characterized in that it comprises a clamping device with concentric jaws capable of assuming a clamping position of the lens ophthalmic by its edge when it is in place on the support plate, the jaws each comprising a support finger and a portion forming a foot opposite said finger and opposite the support plate, this clamping position corresponding to an automatic mode of the device in which the lens is kept fixed relative to the support plate; and in that the clamping device further comprises at least one support position in which the jaws are tightened so that all of the
  • Such a device has two operating modes: automatic and manual.
  • automatic mode the maintenance of the lens by the support plate is advantageously associated with tightening by the edge.
  • manual mode the support plate always supports the weight of the lens but via the jaws which, this time, are no longer used for clamping but act as pillars. Keeping the lens away from the support plate for manual mode is more advantageous than implementing this mode with the lens placed directly on the support plate.
  • the fact that the lens rests on several fingers, rather than on a continuous surface provides a stable support for this lens, even if it is irregularly shaped, which is the case for example with astigmatism correcting lenses which have a slice of variable thickness.
  • the following preferred characteristics can be envisaged, alone or in combination.
  • Each jaw has a first clamping portion attached to said leg portion, as well as a spacer connecting the clamping portion to said finger.
  • the support finger has a rounded portion opposite the portion forming the foot, this rounded portion providing almost point contact between the finger and the lens.
  • Each of the jaws is arranged at the end of an arm pivoting about a fixed axis relative to the support plate.
  • Each of the pivoting arms is attached to the corresponding jaw by a separate portion of the support finger.
  • Each of said arms comprises a semi-circular toothed portion meshing on a toothed ring adapted to be driven by a motor.
  • the clamping device can comprise three jaws, so as to ensure isostatic maintenance of the lens in manual mode.
  • FIG. 1 is a general perspective view of a centralizing and blocking device according to the invention
  • - Figure 2 is a schematic view showing the operating principle of a centralizer-blocker showing the optical path through the ophthalmic lens
  • - Figure 3 is a detailed perspective view of one of the concentric jaws of the centering and locking device of Figure 1
  • - Figure 4 is a perspective view of the centering and centering device of Figure 1, the concentric jaws being in the support position
  • - Figure 5 is a view similar to Figure 4, the concentric jaws being in the clamping position.
  • Figure 1 shows a centralizing and blocking device as it presents itself to its user. It comprises a work desk 1 on which is disposed a centering mechanism 2 of an ophthalmic lens 3. The desk 1 is attached to a frame 4 by means of slides allowing the desk 1 to be translated in the two horizontal directions. A screen 5 is moreover arranged on the frame 4 so as to be oriented so as to be visible to the user working at the desk 1.
  • the centralizing and blocking device also comprises an automated positioning arm 6 and also connected to the frame 4 so as to be able to using a pair of pliers (not visible in the figures) take a tassel placed on a receptacle 7 and place it against the lens 3. Certain internal elements of the centralizing and blocking device of FIG. 1 are highlighted with reference in FIG. 2.
  • a light source 8 is thus placed above the ophthalmic lens 3, a converging lens 9 being interposed between the light source 8 and the lens 3 so as to illuminate the latter with a parallel light beam 10.
  • the ophthalmic lens 3 is schematically placed on a transparent support 11 under which is placed a matrix of HARTMANN 12, well known to those skilled in the art.
  • a camera 13 also reproduces an image of the HARTMANN matrix 12 illuminated by the parallel beam 10 through the ophthalmic lens 3 and projects this image on the screen 5.
  • This arrangement is conventional for a centralizing and blocking device and will therefore not be more described here in detail.
  • Figures 4 and 5 are enlarged views of the console 1 of the centralizer-blocker.
  • the centering mechanism 2 of the ophthalmic lens 3 comprises a set of three jaws 14 with concentric clamping each carried by an arm 15 pivoting about an axis 16 fixed relative to the desk 1.
  • the arms 15 are formed in such a way that their joint rotation about their respective axis 16 allows the three jaws 14 to be brought closer together.
  • the clamping of the jaws 14 is moreover controlled by a motor 17 whose axis is integral with a pinion 18 meshing on a crown 19 adapted to drive the arms 15 in rotation about their axis 16.
  • the arms 15 each in fact comprise a semi-circular toothed portion 20 meshing with the external periphery 21 of the ring 19.
  • the teeth of the pinion 18 and of the periphery outer 21 of the crown 19 have not been shown.
  • the rotation of the pinion 18, under the action of the motor 17, thus drives the crown 19 in rotation to cause the jaws 14 to be tightened or loosened, depending on the direction in which the crown 19 is driven.
  • a cell 22, optical or electromagnetic, allows the motor 17 to know the position of the crown 19.
  • the assembly formed by the arms 15 carrying the jaws 14, and by the crown 19 is disposed above a support plate 23 adapted to allow the light.
  • the jaws 14 are moreover formed of a clamping portion 24 attached to the arms 15, this clamping portion 24 comprising, at its lower part, a flat portion forming a foot 25.
  • the jaws 14 further comprise a finger 26, coaxial with the clamping portion 24, and having a rounded end 27 opposite the clamping portion 24.
  • the finger 26 and the clamping portion 24 are connected to each other by a spacer 28.
  • the clamping portion 24 also has a rounded lateral shape.
  • the centering and blocking device which has just been described operates in the manner indicated below, depending on the mode chosen: automatic or manual. In automatic mode, the starting position of the centralizing and blocking device is such that the jaws 14 are as far apart as possible from each other and are thus each placed near the crown 19.
  • the user places the ophthalmic lens 3 on the support plate 23, approximately in the center of the crown 19.
  • the jaws 14 are then controlled under the action of the motor 17 to come and clamp the lens by its edge, concentrically.
  • Each clamping portion 24 of the jaws 14 therefore comes into contact with the edge of the lens 3 while the latter rests on the support plate 23.
  • the lens 3 being thus immobilized, the optical characteristics of the lens are then measured by the centering and blocking.
  • a tassel is then fixed using the arm 6 on the lens 3, at a location determined by calculation. The fixing of the glans to said location is allowed by a displacement of the desk
  • the centralizing and locking device starts in the same position as for automatic mode.
  • the jaws 14 are then brought closer to each other until they form the vertices of a triangle which can be inscribed in the diameter of the ophthalmic lens which it is desired to treat.
  • the ophthalmic lens 3 is then placed, in accordance with FIG. 4, on the three jaws 14.
  • the flat portion forming a foot rests on the support plate 23 while the rounded end 27 of the finger 26 forms an almost punctual contact surface with the surface of the lens
  • the three jaws 14 thus act in the manner of a lens support tripod 3.
  • the almost point contact provided by the rounded end 27 allows the user, while looking at the screen 5, to move the lens 3 relative to the jaw 14, by hand, until an optical center of the lens 3 coincides with an axis of the machine, this position of the lens 3 being identified using the indications on screen 5.
  • the arm 6 is controlled to bring an acorn on the lens 3, at the place determined by calculation.
  • Alternative embodiments of the centralizing and blocking device can be envisaged without departing from the scope of the invention.
  • the principles aiming at determining the optical center of the lens 3 in the present embodiment can be different from the moment when they require a tightening of the lens by its edge to function in automatic mode and a support of the lens to function in manual mode.
  • the shape and dimensions of the jaws 14 can also vary, just as coatings can be applied to the different portions of the jaws 14.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Ceramic Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Eyeglasses (AREA)

Abstract

The invention relates to a centering clamp device, for the positioning of a drive pin in a position determined by calculation for an ophthalmic lens (3), comprising a locking device (2) with concentric jaws (14), adopting a locking position for the ophthalmic lens (3) on the edge thereof when placed on the support table (23). The locking device (2) further presents a support position in which the jaws (14) are tightened such that the set of support pins are arranged to be covered by the ophthalmic lens (3) such that the ophthalmic lens (3) may rest on said pins whilst being supported by said support plate (23) by means of said sections forming a base (25).

Description

Centreur-bloqueur à mécanisme de serrage modulaire L'invention a trait au domaine de l'équipement destiné au traitement des lentilles ophtalmiques. Elle concerne plus particulièrement un dispositif centreur-bloqueur adapté à déterminer la position d'un centre optique dans le cas d'une lentille unifocale, la position d'un des centres optiques dans le cas de lentilles bifocales ou trifocales, et adapté également à déterminer certains parmi les repères que le fabricant fait usuellement figurer sur la surface des lentilles progressives. Le dispositif centreur-bloqueur est de plus adapté à déterminer par calcul un point de la surface de la lentille définissant l'emplacement au niveau duquel sera posé un pion d'entraînement. Les centreurs-bloqueurs sont des appareils courants dans le domaine de l'optique. Ils interviennent dans le processus de fabrication d'une paire de lunettes, juste avant l'usinage des lentilles ophtalmiques pour les adapter à la forme de la monture de lunettes sélectionnée. Une lentille ophtalmique "brute" se présente en effet sous une forme sensiblement circulaire d'un diamètre suffisant pour pouvoir être montée convenablement dans le cercle de la monture sélectionnée. Un centreur-bloqueur est alors employé pour fixer sur la lentille, généralement au moyen d'un adhésif, un pion d'entraînement généralement dénommé "gland". Ce gland servira, dans l'étape suivante de la fabrication, à entraîner la lentille en rotation pour procéder à l'usinage. La pose du gland sur la lentille est réalisée en un point déterminé par calcul en fonction notamment de la position du centre optique, de la forme de la monture sélectionnée et de certaines caractéristiques du porteur, à savoir son écart ou demi-écart pupillaire ainsi que la hauteur de montage (hauteur des pupilles par rapport à la partie inférieure du cercle de monture). On connaît du document EP 1 080 835 un centreur-bloqueur prévu pour une détermination manuelle du centre optique. Ce centreur-bloqueur comporte une pièce unique formant le support de la lentille ophtalmique et comportant trois pieds, la lentille étant disposée de sorte qu'un motif projeté à travers elle permette de déterminer sur un écran le centre optique recherché. L'utilisateur de la machine agit en déplaçant manuellement la lentille sur son support jusqu'à ce qu'il voit à l'écran un motif lui indiquant que le centre optique de la lentille est aligné avec un axe de la machine. Dans cette position, un bras est adapté à déposer le gland en une position déterminée par calcul. On connaît également du document EP 1 057 589 un centreur-bloqueur comportant un dispositif de centrage automatique de la lentille ophtalmique. Ce centreur-bloqueur comporte des supports escamotables destinés à supporter la lentille, un dispositif de serrage concentrique destiné à prendre le relais des supports escamotables pour fixer la lentille dans une position prédéterminée. Cet ensemble est ensuite déplacé automatiquement par rapport à un dispositif optique similaire à celui décrit précédemment tandis qu'un logiciel permet la détermination du centre optique de la lentille. Le gland est ensuite posé de manière similaire à celle décrite précédemment. Ces centreurs-bloqueurs automatiques sont d'utilisation simple et efficace mais ne peuvent être utilisés pour certains types de verres tels que les verres teintés ou les verres de forte puissance. Le but de l'invention est d'améliorer ce type d'équipement en fournissant un centreur-bloqueur adapté à tout type de lentille ophtalmique. A cet effet, l'invention concerne un dispositif centreur-bloqueur, destiné à permettre la pose d'un pion d'entraînement à un emplacement déterminé par calcul d'une lentille ophtalmique, comportant un plateau de support adapté à laisser passer la lumière et à supporter la lentille ophtalmique ; une source lumineuse adaptée à produire un faisceau lumineux traversant la lentille ophtalmique lorsqu'elle est en place sur le plateau de support ; ainsi qu'un dispositif d'acquisition d'image pour capter le faisceau lumineux après qu'il ait traversé la lentille ophtalmique ; le dispositif centreur- bloqueur étant caractérisé en ce qu'il comporte un dispositif de serrage à mors concentriques propre à prendre une position de serrage de la lentille ophtalmique par sa tranche lorsqu'elle est en place sur le plateau de support, les mors comportant chacun un doigt de support ainsi qu'une portion formant pied à l'opposé dudit doigt et en vis-à-vis du plateau de support, cette position de serrage correspondant à un mode automatique du dispositif dans lequel la lentille est maintenue fixe par rapport au plateau de support ; et en ce que le dispositif de serrage comporte en outre au moins une position de support dans laquelle les mors sont resserrés pour que l'ensemble des doigts de support soit propre à être coiffé par la lentille ophtalmique, de sorte que fa lentille ophtalmique puisse reposer sur lesdits doigts en étant supportée par le plateau de support par l'intermédiaire desdites portions formant pied, cette position de support correspondant à un mode manuel du dispositif dans lequel la lentille est adaptée à être déplacée manuellement par rapport au plateau de support. Un tel dispositif dispose de deux modes de fonctionnement : automatique et manuel. En mode automatique, le maintien de la lentille par le plateau de support est avantageusement associé au serrage par la tranche. En mode manuel, le plateau de support soutien toujours le poids de la lentille mais par l'intermédiaire des mors qui, cette fois, ne servent plus au serrage mais agissent à la manière de piliers. Le maintien de la lentille à distance du plateau de support pour le mode manuel est plus avantageux que de mettre en œuvre ce mode avec la lentille posée directement sur le plateau de support. Le fait que la lentille repose sur plusieurs doigts, plutôt que sur une surface continue, procure un support stable pour cette lentille, même si celfe-ci est de forme irrégulière, ce qui est le cas par exemple des lentilles corrigeant l'astigmatisme qui ont une tranche d'épaisseur variable. Pour des raisons de commodité de réalisation et de fonctionnement, les caractéristiques préférées suivantes peuvent être envisagées, seules ou en combinaison. Chacun des mors comporte une première portion de serrage rattachée à ladite portion formant pied, ainsi qu'une entretoise reliant la portion de serrage audit doigt. Pour chacun des mors, le doigt de support comporte une portion arrondie à l'opposé de la portion formant pied, cette portion arrondie procurant un contact quasi-ponctuel entre le doigt et la lentille. Chacun des mors est disposé au bout d'un bras pivotant autour d'un axe fixe par rapport au plateau de support. Chacun des bras pivotants est rattaché au mors correspondant par une portion distincte du doigt de support. Chacun desdits bras comporte une portion dentée semi-circulaire engrenant sur une couronne dentée adaptée à être entraînée par un moteur. Le dispositif de serrage peut comporter trois mors, de sorte à assurer un maintien isostatique de la lentille en mode manuel. D'autres caractéristiques et avantages de l'invention apparaissent à la lumière de la description qui va suivre d'un mode de réalisation préféré donné à titre d'exemple non limitatif, description faite en référence aux dessins annexés dans lesquels : - la figure 1 est une vue générale en perspective d'un centreur-bloqueur selon l'invention ; - la figure 2 est une vue schématique représentant le principe de fonctionnement d'un centreur-bloqueur en montrant le chemin optique traversant la lentille ophtalmique ; - la figure 3 est une vue de détail en perspective de l'un des mors concentriques du centreur-bloqueur de la figure 1 ; - la figure 4 est une vue en perspective du dispositif de centrage du centreur-bloqueur de la figure 1 , les mors concentriques étant en position de support ; - la figure 5 est une vue similaire à la figure 4, les mors concentriques étant en position de serrage. La figure 1 montre un centreur-bloqueur tel qu'il se présente à son utilisateur. Il comporte un pupitre de travail 1 sur lequel est disposé un mécanisme de centrage 2 d'une lentille ophtalmique 3. Le pupitre 1 est rattaché à un bâti 4 par l'intermédiaire de glissières permettant au pupitre 1 une translation selon les deux directions horizontales. Un écran 5 est de plus disposé sur le bâti 4 de manière à être orienté pour être visible de l'utilisateur travaillant au pupitre 1. Le centreur-bloqueur comporte également un bras de positionnement 6 automatisé et également relié au bâti 4 de sorte à pouvoir prendre à l'aide d'une pince (non visible sur les figures) un gland disposé sur un réceptacle 7 et à venir le poser contre la lentille 3. Certains éléments internes du centreur-bloqueur de la figure 1 sont mis en évidence en référence à la figure 2. Une source lumineuse 8 est ainsi disposée au-dessus de la lentille ophtalmique 3, une lentille convergente 9 étant intercalée entre la source lumineuse 8 et la lentille 3 de manière à éclairer cette dernière d'un faisceau lumineux parallèle 10. Sur la figure 2, la lentille ophtalmique 3 est schématiquement posée sur un support 11 transparent sous lequel est disposée une matrice de HARTMANN 12, bien connue de l'homme du métier. Une caméra 13 restitue par ailleurs une image de la matrice de HARTMANN 12 éclairée par le faisceau parallèle 10 à travers la lentille ophtalmique 3 et projette cette image sur l'écran 5. Cette disposition est classique pour un centreur-bloqueur et ne sera donc pas plus décrite ici en détail. Les figures 4 et 5 sont des vues agrandies du pupitre 1 du centreur-bloqueur. Le mécanisme de centrage 2 de la lentille ophtalmique 3 comporte un jeu de trois mors 14 à serrage concentrique portés chacun par un bras 15 pivotant autour d'un axe 16 fixe par rapport au pupitre 1. Les bras 15 sont formés de telle manière que leur rotation conjointe autour de leur axe 16 respectif permette le rapprochement des trois mors 14. Le serrage des mors 14 est de plus commandé par un moteur 17 dont l'axe est solidaire d'un pignon 18 engrenant sur une couronne 19 adaptée à entraîner les bras 15 en rotation autour de leur axe 16. Les bras 15 comportent en effet chacun une portion dentée semi-circulaire 20 engrenant avec la périphérie externe 21 de la couronne 19. Pour ne pas alourdir les figures, les dentures du pignon 18 et de la périphérie externe 21 de la couronne 19 n'ont pas été représentées. La rotation du pignon 18, sous l'action du moteur 17, entraîne ainsi en rotation la couronne 19 pour provoquer le serrage ou le desserrage des mors 14, en fonction du sens dans lequel est entraînée la couronne 19. Une cellule 22, optique ou électromagnétique, permet au moteur 17 de connaître la position de la couronne 19. L'ensemble formé par les bras 15 portant les mors 14, et par la couronne 19 est disposé au-dessus d'un plateau de support 23 adapté à laisser passer la lumière. Les mors 14 sont par ailleurs formés d'une portion de serrage 24 rattachée aux bras 15, cette portion de serrage 24 comportant, à sa partie inférieure, une portion plane formant pied 25. Les mors 14 comportent de plus un doigt 26, coaxial à la portion de serrage 24, et présentant une extrémité 27 arrondie à l'opposé de la portion de serrage 24. Le doigt 26 et la portion de serrage 24 sont rattachés l'un à l'autre par une entretoise 28. La portion de serrage 24 présente également une forme latérale arrondie. Le centreur-bloqueur qui vient d'être décrit fonctionne de la manière indiquée ci-après, en fonction du mode choisi : automatique ou manuel. En mode automatique, la position de départ du centreur-bloqueur est telle que les mors 14 sont le plus possible écartés les uns des autres et sont ainsi disposés chacun à proximité de la couronne 19. L'utilisateur place ensuite la lentille ophtalmique 3 sur le plateau de support 23, approximativement au centre de la couronne 19. Les mors 14 sont ensuite commandés sous l'action du moteur 17 pour venir serrer la lentille par sa tranche, de manière concentrique. Chaque portion de serrage 24 des mors 14 entre donc en contact avec la tranche de la lentille 3 pendant que celle-ci repose sur le plateau de support 23. La lentille 3 étant ainsi immobilisée, les caractéristiques optiques de la lentille sont alors mesurées par le centreur-bloqueur. Un gland est ensuite fixé grâce au bras 6 sur la lentille 3, à un emplacement déterminé par calcul. La fixation du gland audit emplacement est permise par un déplacement du pupitreThe invention relates to the field of equipment intended for the treatment of ophthalmic lenses. It relates more particularly to a centering-blocking device adapted to determine the position of an optical center in the case of a single focal lens, the position of one of the optical centers in the case of bifocal or trifocal lenses, and also adapted to determine some of the marks that the manufacturer usually displays on the surface of progressive lenses. The centering-blocking device is further adapted to determine by calculation a point on the surface of the lens defining the location at which a drive pin will be placed. Central blockers are common devices in the field of optics. They are involved in the manufacturing process of a pair of glasses, just before machining the ophthalmic lenses to adapt them to the shape of the selected glasses frame. A "rough" ophthalmic lens is in fact in a substantially circular shape with a diameter sufficient to be able to be mounted properly in the circle of the selected frame. A centering and blocking device is then used to fix on the lens, generally by means of an adhesive, a drive pin generally called "glans". This acorn will be used, in the next stage of manufacture, to drive the lens in rotation to carry out the machining. The placement of the glans on the lens is carried out at a point determined by calculation depending in particular on the position of the optical center, the shape of the frame selected and certain characteristics of the wearer, namely his pupillary distance or half-distance as well as the mounting height (height of the pupils in relation to the lower part of the mounting circle). Document EP 1 080 835 discloses a centralizing and blocking device provided for manual determination of the optical center. This centralizer-blocker comprises a single piece forming the support of the ophthalmic lens and comprising three feet, the lens being arranged so that a pattern projected through it makes it possible to determine on a screen the desired optical center. The user of the machine acts by manually moving the lens on its support until he sees a pattern on the screen indicating that the optical center of the lens is aligned with an axis of the machine. In this position, an arm is adapted to deposit the glans in a position determined by calculation. Document EP 1 057 589 also discloses a centering and blocking device comprising an automatic centering device for the ophthalmic lens. This centering and blocking device comprises retractable supports intended to support the lens, a concentric clamping device intended to take over from the retractable supports for fixing the lens in a predetermined position. This assembly is then automatically moved relative to an optical device similar to that described above while software allows the determination of the optical center of the lens. The glans is then placed similarly to that described above. These automatic centering and blocking devices are simple and effective to use but cannot be used for certain types of glass such as tinted glasses or high power glasses. The object of the invention is to improve this type of equipment by providing a centralizing and blocking device suitable for any type of ophthalmic lens. To this end, the invention relates to a centering-blocking device, intended to allow the installation of a drive pin at a location determined by calculation of an ophthalmic lens, comprising a support plate adapted to allow light to pass through and to support the ophthalmic lens; a light source adapted to produce a light beam passing through the ophthalmic lens when it is in place on the support plate; as well as an image acquisition device for capturing the light beam after it has passed through the ophthalmic lens; the centering and blocking device being characterized in that it comprises a clamping device with concentric jaws capable of assuming a clamping position of the lens ophthalmic by its edge when it is in place on the support plate, the jaws each comprising a support finger and a portion forming a foot opposite said finger and opposite the support plate, this clamping position corresponding to an automatic mode of the device in which the lens is kept fixed relative to the support plate; and in that the clamping device further comprises at least one support position in which the jaws are tightened so that all of the support fingers are suitable for being capped by the ophthalmic lens, so that the ophthalmic lens can rest on said fingers being supported by the support plate via said foot portions, this support position corresponding to a manual mode of the device in which the lens is adapted to be moved manually relative to the support plate. Such a device has two operating modes: automatic and manual. In automatic mode, the maintenance of the lens by the support plate is advantageously associated with tightening by the edge. In manual mode, the support plate always supports the weight of the lens but via the jaws which, this time, are no longer used for clamping but act as pillars. Keeping the lens away from the support plate for manual mode is more advantageous than implementing this mode with the lens placed directly on the support plate. The fact that the lens rests on several fingers, rather than on a continuous surface, provides a stable support for this lens, even if it is irregularly shaped, which is the case for example with astigmatism correcting lenses which have a slice of variable thickness. For reasons of convenience of construction and operation, the following preferred characteristics can be envisaged, alone or in combination. Each jaw has a first clamping portion attached to said leg portion, as well as a spacer connecting the clamping portion to said finger. For each of the jaws, the support finger has a rounded portion opposite the portion forming the foot, this rounded portion providing almost point contact between the finger and the lens. Each of the jaws is arranged at the end of an arm pivoting about a fixed axis relative to the support plate. Each of the pivoting arms is attached to the corresponding jaw by a separate portion of the support finger. Each of said arms comprises a semi-circular toothed portion meshing on a toothed ring adapted to be driven by a motor. The clamping device can comprise three jaws, so as to ensure isostatic maintenance of the lens in manual mode. Other characteristics and advantages of the invention appear in the light of the following description of a preferred embodiment given by way of non-limiting example, description made with reference to the accompanying drawings in which: - Figure 1 is a general perspective view of a centralizing and blocking device according to the invention; - Figure 2 is a schematic view showing the operating principle of a centralizer-blocker showing the optical path through the ophthalmic lens; - Figure 3 is a detailed perspective view of one of the concentric jaws of the centering and locking device of Figure 1; - Figure 4 is a perspective view of the centering and centering device of Figure 1, the concentric jaws being in the support position; - Figure 5 is a view similar to Figure 4, the concentric jaws being in the clamping position. Figure 1 shows a centralizing and blocking device as it presents itself to its user. It comprises a work desk 1 on which is disposed a centering mechanism 2 of an ophthalmic lens 3. The desk 1 is attached to a frame 4 by means of slides allowing the desk 1 to be translated in the two horizontal directions. A screen 5 is moreover arranged on the frame 4 so as to be oriented so as to be visible to the user working at the desk 1. The centralizing and blocking device also comprises an automated positioning arm 6 and also connected to the frame 4 so as to be able to using a pair of pliers (not visible in the figures) take a tassel placed on a receptacle 7 and place it against the lens 3. Certain internal elements of the centralizing and blocking device of FIG. 1 are highlighted with reference in FIG. 2. A light source 8 is thus placed above the ophthalmic lens 3, a converging lens 9 being interposed between the light source 8 and the lens 3 so as to illuminate the latter with a parallel light beam 10. In FIG. 2, the ophthalmic lens 3 is schematically placed on a transparent support 11 under which is placed a matrix of HARTMANN 12, well known to those skilled in the art. A camera 13 also reproduces an image of the HARTMANN matrix 12 illuminated by the parallel beam 10 through the ophthalmic lens 3 and projects this image on the screen 5. This arrangement is conventional for a centralizing and blocking device and will therefore not be more described here in detail. Figures 4 and 5 are enlarged views of the console 1 of the centralizer-blocker. The centering mechanism 2 of the ophthalmic lens 3 comprises a set of three jaws 14 with concentric clamping each carried by an arm 15 pivoting about an axis 16 fixed relative to the desk 1. The arms 15 are formed in such a way that their joint rotation about their respective axis 16 allows the three jaws 14 to be brought closer together. The clamping of the jaws 14 is moreover controlled by a motor 17 whose axis is integral with a pinion 18 meshing on a crown 19 adapted to drive the arms 15 in rotation about their axis 16. The arms 15 each in fact comprise a semi-circular toothed portion 20 meshing with the external periphery 21 of the ring 19. To avoid weighing down the figures, the teeth of the pinion 18 and of the periphery outer 21 of the crown 19 have not been shown. The rotation of the pinion 18, under the action of the motor 17, thus drives the crown 19 in rotation to cause the jaws 14 to be tightened or loosened, depending on the direction in which the crown 19 is driven. A cell 22, optical or electromagnetic, allows the motor 17 to know the position of the crown 19. The assembly formed by the arms 15 carrying the jaws 14, and by the crown 19 is disposed above a support plate 23 adapted to allow the light. The jaws 14 are moreover formed of a clamping portion 24 attached to the arms 15, this clamping portion 24 comprising, at its lower part, a flat portion forming a foot 25. The jaws 14 further comprise a finger 26, coaxial with the clamping portion 24, and having a rounded end 27 opposite the clamping portion 24. The finger 26 and the clamping portion 24 are connected to each other by a spacer 28. The clamping portion 24 also has a rounded lateral shape. The centering and blocking device which has just been described operates in the manner indicated below, depending on the mode chosen: automatic or manual. In automatic mode, the starting position of the centralizing and blocking device is such that the jaws 14 are as far apart as possible from each other and are thus each placed near the crown 19. The user then places the ophthalmic lens 3 on the support plate 23, approximately in the center of the crown 19. The jaws 14 are then controlled under the action of the motor 17 to come and clamp the lens by its edge, concentrically. Each clamping portion 24 of the jaws 14 therefore comes into contact with the edge of the lens 3 while the latter rests on the support plate 23. The lens 3 being thus immobilized, the optical characteristics of the lens are then measured by the centering and blocking. A tassel is then fixed using the arm 6 on the lens 3, at a location determined by calculation. The fixing of the glans to said location is allowed by a displacement of the desk
1 par rapport au bâti 4 et/ou par un positionnement piloté du bras 6. En ce qui concerne le mode manuel, le centreur-bloqueur démarre dans la même position que pour le mode automatique. Les mors 14 sont ensuite rapprochés les uns des autres jusqu'à ce qu'ils forment les sommets d'un triangle qui peut être inscrit dans le diamètre de la lentille ophtalmique que l'on désire traiter. La lentille ophtalmique 3 est alors posée, conformément à la figure 4, sur les trois mors 14. Au niveau de chacun des mors 14, la portion plane formant pied s'appuie sur le plateau de support 23 tandis que l'extrémité arrondie 27 du doigt 26 forme une surface de contact quasi ponctuelle avec la surface de la lentille1 relative to the frame 4 and / or by a controlled positioning of the arm 6. With regard to manual mode, the centralizing and locking device starts in the same position as for automatic mode. The jaws 14 are then brought closer to each other until they form the vertices of a triangle which can be inscribed in the diameter of the ophthalmic lens which it is desired to treat. The ophthalmic lens 3 is then placed, in accordance with FIG. 4, on the three jaws 14. At each of the jaws 14, the flat portion forming a foot rests on the support plate 23 while the rounded end 27 of the finger 26 forms an almost punctual contact surface with the surface of the lens
3. Les trois mors 14 agissent ainsi à la manière d'un trépied de support de la lentille 3. Le contact quasi ponctuel procuré par l'extrémité arrondie 27 permet à l'utilisateur, tout en regardant l'écran 5, de déplacer la lentille 3 par rapport au mors 14, à la main, jusqu'à ce qu'un centre optique de la lentille 3 coïηcide avec un axe de la machine, cette position de la lentille 3 étant repérée grâce aux indications de l'écran 5. Lorsque la lentille 3 est ainsi dans la position voulue, le bras 6 est commandé pour amener un gland sur la lentille 3, à l'endroit déterminé par calcul. Des variantes de réalisation du centreur-bloqueur peuvent être envisagées sans pour autant sortir du cadre de l'invention. Notamment, les principes visant à déterminer le centre optique de la lentille 3 dans la présente réalisation, peuvent être différents à partir du moment où ils nécessitent un serrage de la lentille par sa tranche pour fonctionner en mode automatique et un support de la lentille pour fonctionner en mode manuel. La forme et les dimensions des mors 14 peuvent de plus varier, de même que des revêtements peuvent être appliqués sur les différentes portions des mors 14. 3. The three jaws 14 thus act in the manner of a lens support tripod 3. The almost point contact provided by the rounded end 27 allows the user, while looking at the screen 5, to move the lens 3 relative to the jaw 14, by hand, until an optical center of the lens 3 coincides with an axis of the machine, this position of the lens 3 being identified using the indications on screen 5. When the lens 3 is thus in the desired position, the arm 6 is controlled to bring an acorn on the lens 3, at the place determined by calculation. Alternative embodiments of the centralizing and blocking device can be envisaged without departing from the scope of the invention. In particular, the principles aiming at determining the optical center of the lens 3 in the present embodiment, can be different from the moment when they require a tightening of the lens by its edge to function in automatic mode and a support of the lens to function in manual mode. The shape and dimensions of the jaws 14 can also vary, just as coatings can be applied to the different portions of the jaws 14.

Claims

REVENDICATIONS
1. Dispositif centreur-bloqueur, destiné à permettre la pose d'un pion d'entraînement à un emplacement déterminé par calcul d'une lentille ophtalmique (3), comportant un plateau de support (23) adapté à laisser passer la lumière et à supporter la lentille ophtalmique (3) ; une source lumineuse (8) adaptée à produire un faisceau lumineux (10) traversant la lentille ophtalmique (3) lorsqu'elle est en place sur le plateau de support (23) ; ainsi qu'un dispositif d'acquisition d'image (13) pour capter le faisceau lumineux après qu'il ait traversé la lentille ophtalmique (3) ; le dispositif centreur-bloqueur étant caractérisé en ce qu'il comporte un dispositif de serrage (2) à mors concentriques (14) propre à prendre une position de serrage de la lentille ophtalmique (3) par sa tranche lorsqu'elle est en place sur le plateau de support (23), les mors (14) comportant chacun un doigt de support (26) ainsi qu'une portion formant pied (25) à l'opposé dudit doigt (26) et en vis-à-vis du plateau de support (23), cette position de serrage correspondant à un mode automatique du dispositif dans lequel la lentille (3) est maintenue fixe par rapport au plateau de support (23) ; et en ce que le dispositif de serrage (2) comporte en outre au moins une position de support dans laquelle les mors (14) sont resserrés pour que l'ensemble des doigts de support (26) soit propre à être coiffé par la lentille ophtalmique (3), de sorte que la lentille ophtalmique (3) puisse reposer sur lesdits doigts (26) en étant supportée par le plateau de support (23) par l'intermédiaire desdites portions formant pied (25), cette position de support correspondant à un mode manuel du dispositif dans lequel la lentille (3) est adaptée à être déplacée manuellement par rapport au plateau de support (23). 1. A centralizing-blocking device, intended to allow the installation of a drive pin at a location determined by calculation of an ophthalmic lens (3), comprising a support plate (23) adapted to let the light through and to support the ophthalmic lens (3); a light source (8) adapted to produce a light beam (10) passing through the ophthalmic lens (3) when it is in place on the support plate (23); and an image acquisition device (13) for capturing the light beam after it has passed through the ophthalmic lens (3); the centering-blocking device being characterized in that it comprises a clamping device (2) with concentric jaws (14) suitable for taking a position for clamping the ophthalmic lens (3) by its edge when it is in place on the support plate (23), the jaws (14) each comprising a support finger (26) as well as a portion forming a foot (25) opposite said finger (26) and opposite the plate support (23), this clamping position corresponding to an automatic mode of the device in which the lens (3) is held fixed relative to the support plate (23); and in that the clamping device (2) further comprises at least one support position in which the jaws (14) are tightened so that the assembly of support fingers (26) is suitable for being capped by the ophthalmic lens (3), so that the ophthalmic lens (3) can rest on said fingers (26) while being supported by the support plate (23) via said foot portions (25), this support position corresponding to a manual mode of the device in which the lens (3) is adapted to be moved manually relative to the support plate (23).
2. Dispositif centreur-bloqueur selon la revendication 1 , caractérisé en ce que chacun des mors (14) comporte une première portion de serrage (24) rattachée à ladite portion formant pied (25), ainsi qu'une entretoise (28) reliant la portion de serrage (24) audit doigt (26). 2. A centering and blocking device according to claim 1, characterized in that each of the jaws (14) comprises a first clamping portion (24) attached to said portion forming a foot (25), as well as a spacer (28) connecting the clamping portion (24) to said finger (26).
3. Dispositif centreur-bloqueur selon l'une des revendications 1 et 2, caractérisé en ce que, pour chacun des mors (14), le doigt de support (26) comporte une portion arrondie (27) à l'opposé de la portion formant pied (25). 3. A centering and blocking device according to one of claims 1 and 2, characterized in that, for each of the jaws (14), the support finger (26) has a rounded portion (27) opposite the portion forming a foot (25).
4. Dispositif centreur-bloqueur selon l'une des revendications 1 à 3, caractérisé en ce que chacun des mors (14) est disposé au bout d'un bras (15) pivotant autour d'un axe (16) fixe par rapport au plateau de support (23). 4. A centering and blocking device according to one of claims 1 to 3, characterized in that each of the jaws (14) is disposed at the end of an arm (15) pivoting about an axis (16) fixed relative to the support plate (23).
5. Dispositif centreur-bloqueur selon la revendication 4, caractérisé en ce que chacun des bras pivotants (15) est rattaché au mors (14) correspondant par une portion distincte du doigt de support (26). 5. A centering and blocking device according to claim 4, characterized in that each of the pivoting arms (15) is attached to the jaw (14) corresponding by a separate portion of the support finger (26).
6. Dispositif centreur-bloqueur selon l'une des revendications 4 et6. A centralizing and blocking device according to one of claims 4 and
5, caractérisé en ce que chacun desdits bras (15) comporte une portion dentée semi-circulaire (20) engrenant sur une couronne dentée (19) adaptée à être entraînée par un moteur (17). 5, characterized in that each of said arms (15) comprises a semi-circular toothed portion (20) meshing on a toothed ring (19) adapted to be driven by a motor (17).
7. Dispositif centreur-bloqueur selon l'une des revendications 1 à 6, caractérisé en ce que le dispositif de serrage (2) comporte trois mors (14). 7. A centering and blocking device according to one of claims 1 to 6, characterized in that the clamping device (2) has three jaws (14).
PCT/FR2004/002583 2003-10-16 2004-10-12 Centring clamp with modular locking mechanism WO2005037487A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR0312119A FR2861005A1 (en) 2003-10-16 2003-10-16 Centering and locking unit for ophthalmic lenses has concentric jaws that hold lens by its edges as a light beam is passed through it
FR03/12119 2003-10-16

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WO2005037487A1 true WO2005037487A1 (en) 2005-04-28

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100386179C (en) * 2005-05-24 2008-05-07 亚洲光学股份有限公司 Reset certering system
CN103959142A (en) * 2011-11-29 2014-07-30 埃西勒国际通用光学公司 Ophthalmic lens holder for a centering device

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007268700A (en) * 2006-03-31 2007-10-18 Nidek Co Ltd Cup mounting device
FR2974424B1 (en) 2011-04-21 2013-09-13 Essilor Int OPHTHALMIC LENS HOLDER
CN112975653A (en) * 2021-02-05 2021-06-18 何宽 Machining device for elliptical ring-shaped optical glass

Citations (1)

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Publication number Priority date Publication date Assignee Title
EP1057589A1 (en) * 1999-05-27 2000-12-06 Briot International Device for centering and positioning a spectacle glass blank

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1057589A1 (en) * 1999-05-27 2000-12-06 Briot International Device for centering and positioning a spectacle glass blank

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100386179C (en) * 2005-05-24 2008-05-07 亚洲光学股份有限公司 Reset certering system
CN103959142A (en) * 2011-11-29 2014-07-30 埃西勒国际通用光学公司 Ophthalmic lens holder for a centering device
CN103959142B (en) * 2011-11-29 2015-10-07 埃西勒国际通用光学公司 For the lens support of centering apparatus

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