EP1993797B1 - Method for drilling an ophthalmic lens to obtain the desired shape and dimension of a hole to be drilled in said lens - Google Patents

Method for drilling an ophthalmic lens to obtain the desired shape and dimension of a hole to be drilled in said lens Download PDF

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Publication number
EP1993797B1
EP1993797B1 EP07731085.2A EP07731085A EP1993797B1 EP 1993797 B1 EP1993797 B1 EP 1993797B1 EP 07731085 A EP07731085 A EP 07731085A EP 1993797 B1 EP1993797 B1 EP 1993797B1
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EP
European Patent Office
Prior art keywords
lens
drill bit
drilling
drill
setpoint
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Application number
EP07731085.2A
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German (de)
French (fr)
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EP1993797A1 (en
Inventor
Romain Batherosse
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EssilorLuxottica SA
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Essilor International Compagnie Generale dOptique SA
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Publication of EP1993797A1 publication Critical patent/EP1993797A1/en
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B28WORKING CEMENT, CLAY, OR STONE
    • B28DWORKING STONE OR STONE-LIKE MATERIALS
    • B28D1/00Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor
    • B28D1/14Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor by boring or drilling
    • B28D1/143Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor by boring or drilling lens-drilling machines

Definitions

  • the present invention relates to a method of drilling an ophthalmic lens according to the preamble of claim 1.
  • the trimming of the lens and, possibly, the reduction of the sharp edges (chamfering) are followed by the appropriate drilling of the lenses to allow the fixation of the branches and the nasal bridge of the mount without circle.
  • Drilling can be done on a grinder or on a separate drilling machine. To perform the drilling on a machine incorporating the clipping means, this machine is then provided, in addition to the clipping means, drilling specific means.
  • bypass drilling To make holes of different sizes and / or different shapes with the same drill, it implements a particular drilling method called bypass drilling.
  • a piercing method according to the preamble of claim 1.
  • Bypass drilling is performed as follows. After memorizing the desired shape and size of the drilling hole to be made and the position of this hole on the surface of the lens, the drill bit is positioned opposite the stored position of the hole to be drilled. The lens is then pierced by means of a relative advance movement of the drill bit relative to the lens along the axis of rotation of the drill. Then, the drill, engaged in the lens, is moved transversely, that is to say substantially in the plane of the lens, in the manner of a mill in a substantially circular movement.
  • This transverse displacement of the drill is controlled according to piloting instructions corresponding to the desired shape and size stored. However, it is observed that the hole obtained is often smaller in diameter than that desired and stored.
  • the object of the invention is to limit the difference between the dimension obtained and the desired size of the drilling hole.
  • the drill is moved transversely with respect to its mobility in advance and it is the lateral portion of the drill that mills the lens in the manner of a milling cutter. It follows that cutting forces are exerted on the drill transversely to its axis, so that the drill then bends under the effect of these transverse cutting forces, which prevents it from reaching the dimensions of the outline of the drill. hole corresponding to the driving instruction.
  • control setpoint is corrected. according to parameters that influence the observed size difference, to compensate for this difference.
  • the desired size and shape of the hole is then obtained.
  • the material of the lens is one of the parameters on which the dimension dimension difference observed depends. The harder the material of the lens at the point of drilling, the more the drill flexes and the greater the difference in dimension.
  • the setpoint correction corresponding to an enlargement of the size of the hole as a function of at least one of the parameters on which the dimension dimension difference observed depends, allows the drill which bends to reach the dimension of the contour of the desired hole.
  • the widening of the desired size of the hole is adapted according to a method taking into account at least one of the mechanical and / or geometric characteristics of the lens and / or drill bit so that the lower dimension reached by the drill is the dimension of the hole outline to the desired size.
  • control set of the transverse displacement of the drill bit is corrected according to a mechanical and / or geometric characteristic of the lens, for example as a function of at least the thickness of the lens .
  • the thickness of the lens is one of the parameters on which the dimension dimension difference observed depends. Indeed, the greater the thickness of the lens at the piercing point, the more the drill bends and the more the difference in dimension is important.
  • control set of the transverse displacement of the drill bit is corrected according to at least one mechanical and / or geometric characteristic of the drill bit.
  • the mechanical characteristics of the drill bit are also part of the parameters on which the dimension dimension difference observed depends. In fact, the smaller the diameter of the drill bit, and / or the less hard the drill material, the greater the difference in dimension.
  • control setpoint for the transverse displacement of the drill bit is corrected according to the advance and / or the depth of the milling pass.
  • the correction of the steering setpoint for the transverse displacement of the drill bit is obtained by means of curves or reference charts.
  • the milling step comprises one or more uncorrected milling passes subsequent to the corrected milling pass and for which the control instruction for the transverse displacement of the drill bit corresponds directly to the shape and the desired size of the drilling hole.
  • This uncorrected milling pass results in a more accurate hole size and shape in the event that the rating obtained after the setpoint correction is still lower than the desired dimension.
  • the invention also relates to a method of drilling a lens according to claim 8.
  • the control setpoint correction is thus made from the measurement of the component of a force that the drill undergoes.
  • the value of this component of the force experienced by the drill is relative to the bending force experienced by the drill when it mills the lens being moved transversely and thus is also relative to the observed difference in dimension.
  • the correction of the driving instruction for the transverse displacement of the drill bit is at least partially defined starting from the acquisition of a quantity directly or indirectly representative of at least one transverse component of the effort that the drill undergoes during milling.
  • the correction of the control setpoint is predefined during a milling pass prior to said corrected pass.
  • a quantity representative of at least one transverse component of the force experienced by the drill during the milling is acquired, which makes it possible to define the correction of the control setpoint of the corrected milling pass.
  • control setpoint is dynamically performed during said corrected milling pass.
  • the correction of the setpoint can thus be adapted during the corrected milling pass as a function of the transverse component that the drill undergoes to reach as precisely as possible the desired dimension at each point of the contour of the hole to be made.
  • the correction of the steering setpoint of the transverse displacement of the drill is at least partly predefined from the acquisition of a quantity directly or indirectly representative of at least one axial component of the effort that the drill undergoes during drilling.
  • FIG. 4 To the figure 4 there is shown a trimming and drilling device 6 equipped with a drilling module 625.
  • the trimming function of the trimming and drilling device 6 can be performed in the form of any cutting or material removal machine adapted to modify the contour of the ophthalmic lens to match that of the frame or "circle" of a selected mount.
  • a machine may consist for example of a grinder, a laser cutting machine or jet water, etc.
  • the shaping device comprises, in a manner known per se, an automatic grinder 610, commonly called digital.
  • This grinder comprises, in this case, a flip-flop 611, which is freely pivotally mounted about a first axis A1, in practice a horizontal axis, on a frame.
  • the grinder is equipped with support means able to clamp and rotate an ophthalmic lens.
  • These support means comprise two shafts and rotation drive 612, 613. These two shafts 612, 613 are aligned with each other along a second axis A2, called locking pin, parallel to the first axis A1.
  • the two shafts 612, 613 are rotated synchronously by a motor (not shown), via a common drive mechanism (not shown) embedded on the flip-flop 611.
  • This common synchronous rotation drive mechanism is of type current, known in itself.
  • the ROT rotation of the shafts 612, 613 is driven by a central electronic and computer system (not shown) such as an integrated microcomputer or a set of dedicated integrated circuits.
  • Each of the shafts 612, 613 has a free end which faces the other and is equipped with a locking nose (not shown). These locking noses are not always fixed on the shafts 612, 613. They are in fact previously used by gripping means (not shown) to lock the lens before being transferred to the present clipping and drilling device 6 by staying in contact with the transferred lens.
  • the shaft 613 is movable in translation along the blocking axis A2, facing the other shaft 612, to effect the compression in axial compression of the lens between the two locking noses.
  • the shaft 613 is controlled for this axial translation by a drive motor via an actuating mechanism (not shown) controlled by the central electronic and computer system.
  • the other shaft 612 is fixed in translation along the blocking axis A2.
  • the trimming and drilling device 6 comprises, on the other hand, a machining drill, here a train of at least one grinding wheel 614, which is wedged in rotation on a third axis A3 parallel to the first axis A1, and which is also properly rotated by a motor not shown.
  • a machining drill here a train of at least one grinding wheel 614, which is wedged in rotation on a third axis A3 parallel to the first axis A1, and which is also properly rotated by a motor not shown.
  • the grinder 610 comprises a train of several grinding wheels 614 mounted coaxially on the third axis A3, for a roughing and finish of the edging of the ophthalmic lens to be machined. These different grinding wheels are each adapted to the material of the cut-out lens and the type of operation performed (roughing, finishing, mineral or synthetic material, etc.).
  • the grinding wheel is attached to a common shaft of axis A3 ensuring their rotational drive during the edging operation.
  • This common shaft which is not visible in the figures shown, is rotated by an electric motor 620 driven by the electronic and computer system.
  • the wheel train 614 is also movable in translation along the axis A3 and is controlled in this translation by a drive motor.
  • a drive motor Concretely, the entire wheel train 614, its shaft and its motor is carried by a carriage 621 which is itself mounted on slides 622 secured to the frame for sliding along the third axis A3.
  • the translational movement of the wheel trolley 621 is called “transfer” and is noted TRA on the figure 3 .
  • This transfer is controlled by a motorized drive mechanism (not shown), such as a screw and nut or rack system, controlled by the central electronic and computer system.
  • the pivoting capacity of the lever 611 about the axis A1 is used.
  • This pivoting causes indeed a displacement, here substantially vertical, of the lens sandwiched between the shafts 612, 613 which brings the lens closer or away from the grinding wheels 614.
  • This mobility which makes it possible to restore the shape of the desired and programmed edging in an electronic system. and computer science, is called restitution and is noted RES in the figures. This RES restitution mobility is controlled by the central electronic and computer system.
  • the grinder illustrated by the figure 4 further comprises a finishing module 625 which embeds chamfering and grooving grinders 630, 631 mounted on a common axis 632 and which is movable with a degree of mobility, in a direction substantially transverse to the axis A2 of the shafts 612, 613 maintaining the lens and the axis A5 of the restitution RES.
  • This degree of mobility is called retraction and is noted ESC in the figures.
  • this retraction consists of a pivoting of the finishing module 625 around the axis A3.
  • the module 625 is carried by a lever 626 integral with a tubular sleeve 627 mounted on the carriage 621 to rotate about the axis A3.
  • the sleeve 627 is provided, at its end opposite the lever 626, a toothed wheel 628 which meshes with a pinion (not visible in the figures) fitted to the shaft of an electric motor 629 integral with the trolley 621.
  • the module 625 is provided with a drill 635 whose spindle is equipped with a drill attachment mandrel 637 along a drilling axis A6 (see figure 5 ).
  • the drill 635 is mounted on the module 625 so as to pivot about an axis of orientation A7 substantially transverse to the axis A3 of the grinding wheels 614 as well as to the axis A5 of restitution and, consequently, substantially parallel to the direction of rotation. ESC retraction of the module 625.
  • the drilling axis A6 is thus orientable about the axis of orientation A7, that is to say in a plane close to the vertical.
  • This pivoting orientation of the drill 635 is noted PIV on the figure 4 . This is the only degree of mobility dedicated to drilling.
  • the integration of the drilling function within an edging machine implies that the drill is properly positioned opposite the position of the hole to be drilled on the lens. This positioning is achieved by means of two pre-existing degrees of mobility, independently of the drilling function, which are the retraction ESC on the one hand and the transfer TRA on the other hand. These two degrees of mobility, retraction and transfer are furthermore used to adjust the orientation of the drilling axis A6 of drill 635.
  • the body 634 of the drill 635 has a cylindrical shaft A7 sleeve which is pivotally received in a corresponding bore of the same axis A7 formed in the body of the module 625.
  • the drill 635 can thus pivoting about the axis of orientation A7 over a range of angular positions corresponding to the same inclination of the drilling axis A6 with respect to the lens to be pierced when the module 625 will come into the drilling position.
  • This range of angular positions is physically delimited by two angular stops integral with the body of the module 625.
  • the adjustment means of the orientation comprise, on the one hand, a finger 638 secured to the body 634 of the drill 635 and provided with a spherical end 639 and, on the other hand, a plate 650 carrying a cam path 651 and integral with the frame 601 of the grinder.
  • the plate 650 has a plane useful face 658 which is substantially perpendicular to the transfer direction TRA, or in other words, in the example shown, to the axes A2 and A3. As the axes A2 and A3 are here horizontal, the useful face 858 of the plate 650 is vertical. When the module 625 is in its angular range of adjustment, the useful face 658 of the plate 650 is located opposite the end 639 of the finger 638 of the drill 635.
  • the cam path of the plate 650 is constituted by a trench 651 formed in recess of the useful face 658 of the plate 650.
  • the trimming and drilling device finally comprises means for memorizing the desired shape and size of a drilling hole 700 of the lens, also called the hole to be drilled, and the position of this hole on the surface of the hole. lens.
  • These storage means may consist of a rewritable memory and an interface (for example a keyboard and a screen) for writing in this memory.
  • the desired shape and size of the drilling hole 700 to be made in the lens as well as the position of this drilling hole on the surface of the lens are stored by the storage means of the clipping device and drilling.
  • the electronic processing system 100 manages, in appropriate coordination, the transfer mobilities TRA of the finishing module 625 carrying the drilling, restitution module RES of the clamping and rotation shafts 612, 613, of retraction.
  • ESC of the finisher 625 and optionally rotation ROT of the lens to obtain the relative mobilities of the drill relative to the lens necessary for the realization of the drilling hole.
  • These relative mobilities comprise a relative advance mobility of the drill bit relative to the lens along the axis of rotation of the drill and a mobility of transverse displacement of the drill bit relative to its drilling axis.
  • the relative advance mobility of the drill bit relative to the lens can be obtained by a mobility composed for example from the retraction mobility ESC of the finishing module 625 and the transfer mobility TRA of the module
  • the relative advance mobility of the drill bit relative to the lens can be achieved by means of additional simple mobility by moving the drill bit along its drilling axis relative to the drilling module. finish 625.
  • the lens is drilled by means of the drill bit at a point of origin PO, also called the starting point of drilling.
  • the position of this point of origin PO is chosen substantially in the center of the hole. In the case of an oblong hole this point of origin is chosen to be the center of one of the two semicircles defining the oblong hole.
  • the drilling drill is positioned opposite the original position of the hole 700 to be drilled and the orientation of the drill 637 is adjusted by coordinating control. appropriate transfer mobilities TRA, RES restitution and rotation ROT so that the drilling axis A6 is substantially coincident with the normal to the lens at the point of origin PO considered. After properly orienting the drill, it begins drilling at this point of origin PO. The drill is then rotated and moved in translation along the axis of drilling A7, that is to say according to its mobility in advance, to the point of origin PO until piercing the lens.
  • bypass drilling Since the hole 700 to be drilled is of diameter greater than the diameter of the drill and / or of non-circular shape, a special drilling method, called bypass drilling, is used. According to this method, the drill 637, engaged in the lens, is moved transversely with respect to the drilling axis A6. The drill 637 is thus used in the manner of a milling cutter being moved in a substantially circular manner to remove a given depth of material, until reaching the desired dimension at any point in the contour of the hole 700 to be drilled.
  • the depth of material removed corresponds to the radius of material removed following a movement of the drill substantially circular in the plane transverse to its piercing axis, that is to say substantially in the plane tangent to the lens passing through the point original PO.
  • the hole 700 to be drilled is an oblong hole.
  • the movement of the drill is controlled along a spiral path as represented by the arrows of movement of the drill on the figure 1 .
  • the displacement of the drill 637 along this spiral path firstly comprises an initial milling pass 701 in which the drill is moved rectilinearly along the length L0 of the hole 700 to be made.
  • This initial milling pass 701 is made of "full material", that is to say that the depth of material removed is equal to the diameter of the drill.
  • the transverse displacement of the drill is controlled to perform several milling passes 701, 702, 703 along a path whose shape corresponds to the shape of the desired hole but of smaller size.
  • the trajectory of the drill while keeping the same shape, is enlarged.
  • the paths of these milling passes thus form a spiral.
  • the drill is near the desired contour of the hole to be made.
  • the drill is then driven to perform a milling pass following a control setpoint that corresponds directly to the desired shape and size of the drilling hole.
  • a graph has been plotted on which is reported the diameter Dm of a drilled hole resulting from a control setpoint corresponding to a desired diameter Dms as a function of the thickness Ep of the lens at the piercing point, in the absence of any control setpoint correction.
  • the greater the thickness Ep of the lens at the point of drilling the greater the difference between the obtained diameter Dm of the drilled hole and the desired diameter Dms of the hole is important.
  • the greater the thickness Ep of the lens at the point of drilling the greater the diameter Dm of the hole obtained decreases relative to the desired diameter Dms of this hole. Beyond a certain thickness, the value of the diameter obtained from the hole out of the IT tolerance range set.
  • This correction method makes it possible to obtain the desired shape and size of the hole to be drilled according to a bypass or milling method, as presented above.
  • a setpoint correction is made for controlling the transverse displacement of the drill as a function of the thickness at the piercing point of the lens.
  • the distribution of points on the figure 2 giving the obtained diameter Dm of the hole as a function of the thickness Ep of the lens at the piercing point, makes it possible to determine a correction function giving the control setpoint correction to be applied to the transverse displacement of the drill according to the thickness of the lens at the piercing point to obtain the desired diameter Dms of the hole.
  • the correction of the steering setpoint of the transverse displacement of the drill bit 637 consists in an enlargement of the size of the hole to be made according to a method taking into account the thickness of the lens.
  • this control setpoint correction consists in increasing the depth of pass so as to compensate for the difference observed between the dimension obtained and the desired size of the hole.
  • this correction function is substantially linear.
  • a corrected milling pass is carried out for which the instruction The steering of the transverse displacement of the drill bit is corrected according to the correction function mentioned above, that is to say here depending on the thickness of the lens.
  • the value of the diameter obtained is within the given tolerance interval, as represented on the graph of the figure 3 .
  • the correction of the control setpoint of the transverse displacement of the drill bit can thus be obtained by means of reference curves giving the obtained diameter of the hole as a function of a parameter such as the thickness of the lens at the piercing point. It is also possible to make abacuses giving directly the correction of the control setpoint to be applied.
  • a setpoint correction is made for controlling the transverse displacement of the drill as a function of the material of the lens. For this, a curve similar to that of the first embodiment is produced, but this time not according to the thickness, but as a function of the material of the lens and for a determined thickness.
  • a control setpoint correction is performed as a function of the thickness of the lens at the piercing point and as a function of the material of the lens.
  • a control setpoint correction is performed as a function of the thickness of the lens at the piercing point and as a function of the material of the lens.
  • curves giving the difference between the diameter obtained and the desired diameter as a function of the thickness (as for the curve shown on FIG. figure 1 ).
  • Each of these curves corresponds to a correction function as described above. It is then sufficient to apply to the milling control instructions, the correction function, interpolated or not, corresponding to the material of the lens to be drilled and the thickness at the piercing point considered.
  • a milling control setpoint correction is made according to the mechanical characteristics of the drill bit. These mechanical characteristics can be the diameter and / or the material of the drill bit, or else other mechanical characteristics:
  • the correction function is obtained in a manner similar to the previous embodiments, from one or more curves. giving the diameter of the hole obtained according to one or more mechanical characteristics of the drill.
  • this third embodiment can be combined with one of the previous modes of execution.
  • the target correction is then performed both as a function of the thickness at the piercing point of the lens, as a function of the material of the lens and as a function of mechanical characteristics of the drill.
  • the correction of the control setpoint for the transverse displacement of the drill bit to be performed dynamically during milling by means of the acquisition of at least one component.
  • the milling force by a suitable force sensor.
  • This milling effort allows from a mathematical formula, which can be obtained or not empirically, to deduce one or more parameters on which depends the correction function, such as the thickness and / or the material of the lens, and / or the mechanical characteristics of the drill.
  • the steering setpoint is then corrected, taking into account the parameter or parameters deduced.
  • the correction of the driving instruction for the transverse displacement of the drill bit can also be at least partially defined from the acquisition of at least one component.
  • the drilling effort (at the point of origin) by a suitable force sensor.
  • this drilling effort makes it possible, from a mathematical formula, obtained or not empirically, to deduce from it one or more parameters on which the correction function depends, and thus to correct the driving instruction.
  • the depth of material removed by the drill during the milling passes can be modified by adapting the control setpoint according to the material of the machined lens and / or the thickness of the milled lens portion, and / or the mechanical characteristics of the drill bit , and / or the advance of the drill.
  • the greater the thickness, and / or the material hardness of the lens the greater the correction made.
  • the lower the mechanical characteristics of the drill that is, the greater the deflection of the drill (resulting from a bending force on the drill), the greater the correction. deposit is important.
  • the greater the advance of the drill the greater the correction made to the driving instruction.
  • the steering setpoint for the transverse displacement of the drill bit is corrected as a function of a magnitude representative of at least one transverse component of the force experienced by said drill. drill when milling the lens.
  • This measured quantity can be directly the transversal component of the effort that the forest undergoes.
  • the magnitude measured may also be the intensity of the current in the motor whose value varies as a function of the transverse force to which the drill is subjected. It is also possible to measure the variations in the advance of the drill in the case of the application of a predefined torque force and to deduce the transverse component of the force experienced by the drill.
  • the deduction of the transverse component of the force experienced by the drill can be made from curves or reference charts obtained for example empirically.
  • the control setpoint correction is then determined from this transverse component (for example by means of curves or reference charts).
  • the correction of the control setpoint is predefined during a milling pass prior to said corrected pass. It is also possible, for greater precision, to determine the driving instruction dynamically during said corrected milling pass.
  • this setpoint correction to be applied corresponds to an enlargement of the size of the hole to compensate for the decrease in size obtained due to the bending forces experienced by the drill.
  • the correction of the steering setpoint of the transverse displacement of the drill is predefined from the acquisition of a magnitude representative of an axial component of the force experienced by the drill during drilling.
  • this magnitude can be directly the axial component itself or, indirectly, the intensity of the motor and / or the advance of the drill from which one can deduce said axial component of the force experienced by the drill.
  • the deduction of the axial component of the force experienced by the drill can be performed from curves or reference charts obtained for example empirically.
  • the control setpoint correction is then determined from this axial component (for example by means of curves or reference charts). It is thus possible from the piercing step and before the step of milling the lens, to determine the control setpoint to from the axial component of the effort that the drill undergoes during drilling.
  • the drill is moved empty, that is to say without removal of material, to the point of origin so as to achieve a closed trajectory.
  • the drill has a diameter of between 0.8 mm and 1mm.
  • this drill can be replaced by a bur.
  • the milling step consists of making passes along a path close to the desired shape of the hole, increasing during the passes the dimension of the shape defined by the trajectory, following a step depending on the depth of material to be removed at each pass, until reaching the desired size of the hole.

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  • Mining & Mineral Resources (AREA)
  • Mechanical Engineering (AREA)
  • Drilling And Boring (AREA)

Description

DOMAINE TECHNIQUE AUQUEL SE RAPPORTE L'INVENTIONTECHNICAL FIELD TO WHICH THE INVENTION REFERS

La présente invention concerne un procédé de perçage d'une lentille ophtalmique selon le préambule de la revendication 1.The present invention relates to a method of drilling an ophthalmic lens according to the preamble of claim 1.

ARRIÈRE-PLAN TECHNOLOGIQUETECHNOLOGICAL BACKGROUND

Lorsque la monture est du type sans cercle, le détourage de la lentille et, éventuellement, l'abattement des arrêtes vives (chanfreinage) sont suivis du perçage approprié des lentilles pour permettre la fixation des branches et du pontet nasal de la monture sans cercle. Le perçage peut être effectué sur une meuleuse ou sur une machine de perçage distincte. Pour réaliser le perçage sur une machine intégrant les moyens de détourage, cette machine est alors pourvue, en plus des moyens de détourage, de moyens spécifiques au perçage.When the mount is of the type without a circle, the trimming of the lens and, possibly, the reduction of the sharp edges (chamfering) are followed by the appropriate drilling of the lenses to allow the fixation of the branches and the nasal bridge of the mount without circle. Drilling can be done on a grinder or on a separate drilling machine. To perform the drilling on a machine incorporating the clipping means, this machine is then provided, in addition to the clipping means, drilling specific means.

Pour réaliser des trous de différentes tailles et/ou de différentes formes avec un même foret, on met en oeuvre une méthode de perçage particulière appelée perçage par contournement. On connaît notamment du document EP 1310327 un procédé de perçage conforme au préambule de la revendication 1.To make holes of different sizes and / or different shapes with the same drill, it implements a particular drilling method called bypass drilling. We know in particular of the document EP 1310327 a piercing method according to the preamble of claim 1.

Le perçage par contournement est réalisé de la manière suivante. Après avoir mémorisé la forme et la dimension souhaitées du trou de perçage à réaliser ainsi que la position de ce trou sur la surface de la lentille, le foret de perçage est positionné en vis-à-vis de la position mémorisée du trou à percer. La lentille est alors percée au moyen d'une mobilité d'avance relative du foret de perçage par rapport à la lentille suivant l'axe de rotation du foret. Puis, le foret, engagé dans la lentille, est déplacé transversalement, c'est-à-dire sensiblement dans le plan de la lentille, à la manière d'une fraise suivant un mouvement sensiblement circulaire.Bypass drilling is performed as follows. After memorizing the desired shape and size of the drilling hole to be made and the position of this hole on the surface of the lens, the drill bit is positioned opposite the stored position of the hole to be drilled. The lens is then pierced by means of a relative advance movement of the drill bit relative to the lens along the axis of rotation of the drill. Then, the drill, engaged in the lens, is moved transversely, that is to say substantially in the plane of the lens, in the manner of a mill in a substantially circular movement.

Ce déplacement transversal du foret est piloté suivant des instructions de pilotage correspondant à la forme et à la dimension souhaitées mémorisées. Cependant, on observe que le trou obtenu est souvent de diamètre plus petit que celui souhaité et mémorisé.This transverse displacement of the drill is controlled according to piloting instructions corresponding to the desired shape and size stored. However, it is observed that the hole obtained is often smaller in diameter than that desired and stored.

OBJET DE L'INVENTIONOBJECT OF THE INVENTION

Le but de l'invention est de limiter l'écart entre la dimension obtenue et la dimension souhaitée du trou de perçage.The object of the invention is to limit the difference between the dimension obtained and the desired size of the drilling hole.

À cet effet, on propose selon l'invention un procédé de perçage conforme à la revendication 1.For this purpose, it is proposed according to the invention a drilling method according to claim 1.

Lors de l'étape de fraisage, le foret est déplacé transversalement par rapport à sa mobilité d'avance et c'est la partie latérale du foret qui usine la lentille à la façon d'une fraise. Il s'ensuit que des efforts de coupe sont exercés sur le foret transversalement à son axe, si bien que le foret fléchit alors sous l'effet de ces efforts transversaux de coupe, ce qui l'empêche d'atteindre les cotes du contour du trou correspondant à la consigne de pilotage.During the milling step, the drill is moved transversely with respect to its mobility in advance and it is the lateral portion of the drill that mills the lens in the manner of a milling cutter. It follows that cutting forces are exerted on the drill transversely to its axis, so that the drill then bends under the effect of these transverse cutting forces, which prevents it from reaching the dimensions of the outline of the drill. hole corresponding to the driving instruction.

Grâce au procédé selon l'invention, la consigne de pilotage est corrigée. en fonction de paramètres qui influent sur l'écart de dimension observé, pour compenser cet écart. On obtient alors la dimension et la forme souhaitée du trou.With the method according to the invention, the control setpoint is corrected. according to parameters that influence the observed size difference, to compensate for this difference. The desired size and shape of the hole is then obtained.

Le matériau de la lentille est un des paramètres dont dépend l'écart de cote de dimension observé. Plus le matériau de la lentille au point de perçage est dur, plus le foret travaille en flexion et plus l'écart de cote est important.The material of the lens is one of the parameters on which the dimension dimension difference observed depends. The harder the material of the lens at the point of drilling, the more the drill flexes and the greater the difference in dimension.

La correction de consigne, correspondant à un élargissement de la dimension du trou en fonction d'au moins un des paramètres dont dépend l'écart de cote de dimension observé, permet au foret qui fléchit d'atteindre la cote du contour du trou souhaité. En effet, l'élargissement de la dimension souhaitée du trou est adapté suivant une méthode prenant en compte au moins une des caractéristiques mécanique et/ou géométrique de la lentille et/ou du foret de perçage de telle sorte que la cote inférieure atteinte par le foret soit la cote du contour du trou à la dimension souhaitée.The setpoint correction, corresponding to an enlargement of the size of the hole as a function of at least one of the parameters on which the dimension dimension difference observed depends, allows the drill which bends to reach the dimension of the contour of the desired hole. Indeed, the widening of the desired size of the hole is adapted according to a method taking into account at least one of the mechanical and / or geometric characteristics of the lens and / or drill bit so that the lower dimension reached by the drill is the dimension of the hole outline to the desired size.

Selon une première caractéristique avantageuse du procédé, on corrige la consigne de pilotage du déplacement transversal du foret de perçage en fonction d'une caractéristique mécanique et/ou géométrique de la lentille, par exemple en fonction d'au moins l'épaisseur de la lentille.According to a first advantageous characteristic of the method, the control set of the transverse displacement of the drill bit is corrected according to a mechanical and / or geometric characteristic of the lens, for example as a function of at least the thickness of the lens .

L'épaisseur de la lentille est un des paramètres dont dépend l'écart de cote de dimension observé. En effet, plus l'épaisseur de la lentille au point de perçage est importante, plus le foret fléchit et plus l'écart de cote est important.The thickness of the lens is one of the parameters on which the dimension dimension difference observed depends. Indeed, the greater the thickness of the lens at the piercing point, the more the drill bends and the more the difference in dimension is important.

Selon une autre caractéristique avantageuse du procédé , on corrige la consigne de pilotage du déplacement transversal du foret de perçage en fonction d'au moins une caractéristique mécanique et/ou géométrique du foret de perçage.According to another advantageous characteristic of the process , the control set of the transverse displacement of the drill bit is corrected according to at least one mechanical and / or geometric characteristic of the drill bit.

Les caractéristiques mécaniques du foret de perçage font aussi partie des paramètres dont dépend l'écart de cote de dimension observé. En effet plus le diamètre du foret est faible, et/ou moins le matériau du foret est dur, plus l'écart de cote est important.The mechanical characteristics of the drill bit are also part of the parameters on which the dimension dimension difference observed depends. In fact, the smaller the diameter of the drill bit, and / or the less hard the drill material, the greater the difference in dimension.

Selon une autre caractéristique avantageuse du procédé, on corrige la consigne de pilotage du déplacement transversal du foret de perçage en fonction de l'avance et/ou de la profondeur de passe du fraisage.According to another advantageous characteristic of the method, the control setpoint for the transverse displacement of the drill bit is corrected according to the advance and / or the depth of the milling pass.

Selon une autre caractéristique avantageuse du procédé, la correction de la consigne de pilotage du déplacement transversal du foret de perçage est obtenue au moyen de courbes ou d'abaques de référence.According to another advantageous characteristic of the method, the correction of the steering setpoint for the transverse displacement of the drill bit is obtained by means of curves or reference charts.

On peut ainsi utiliser des courbes ou des abaques de référence qui en fonction des paramètres dont dépend l'écart de cote de dimension observé, permettent d'obtenir la correction de la consigne de pilotage appropriée.It is thus possible to use reference curves or charts which, depending on the parameters on which the dimension dimension difference observed depends, make it possible to obtain the correction of the appropriate control setpoint.

Selon une autre caractéristique avantageuse du procédé, l'étape de fraisage comporte une ou plusieurs passes de fraisage non corrigées postérieures à la passe de fraisage corrigée et pour laquelle la consigne de pilotage du déplacement transversal du foret de perçage correspond directement à la forme et à la dimension souhaitées du trou de perçage.According to another advantageous feature of the method, the milling step comprises one or more uncorrected milling passes subsequent to the corrected milling pass and for which the control instruction for the transverse displacement of the drill bit corresponds directly to the shape and the desired size of the drilling hole.

Cette passe de fraisage non corrigée permet d'obtenir une dimension et une forme pour le trou plus précises dans le cas où la cote obtenue après la correction de consigne serait encore Inférieure à la cote souhaitée.This uncorrected milling pass results in a more accurate hole size and shape in the event that the rating obtained after the setpoint correction is still lower than the desired dimension.

L'invention concerne également un procédé de perçage d'une lentille conforme à la revendication 8.The invention also relates to a method of drilling a lens according to claim 8.

La correction de consigne de pilotage est ainsi réalisée à partir de la mesure de la composante d'un effort que subit le foret. La valeur de cette composante de l'effort que subit le foret est relative à l'effort de flexion que subit le foret lorsqu'il usine la lentille en étant déplacé transversalement et donc est aussi relative à l'écart de cote observé.The control setpoint correction is thus made from the measurement of the component of a force that the drill undergoes. The value of this component of the force experienced by the drill is relative to the bending force experienced by the drill when it mills the lens being moved transversely and thus is also relative to the observed difference in dimension.

Selon une autre caractéristique avantageuse du procédé, la correction de la consigne de pilotage du déplacement transversal du foret est au moins en partie définie à partir de l'acquisition d'une grandeur directement ou indirectement représentative d'au moins une composante transversale de l'effort que subit le foret lors du fraisage.According to another advantageous characteristic of the method, the correction of the driving instruction for the transverse displacement of the drill bit is at least partially defined starting from the acquisition of a quantity directly or indirectly representative of at least one transverse component of the effort that the drill undergoes during milling.

Le fait de réaliser cette détermination de la correction de consigne lors de l'étape de fraisage permet de déterminer plus précisément l'effort que subit le foret pendant cette étape de fraisage et donc d'améliorer la correction de consigne de pilotage qui doit compenser l'écart de cote lié à cet effort.The fact of making this determination of the setpoint correction during the milling step makes it possible to determine more precisely the effort that the drill undergoes during this milling step and thus to improve the control setpoint correction which must compensate for the rating gap related to this effort.

Selon une autre caractéristique avantageuse du procédé, la correction de la consigne de pilotage est prédéfinie pendant une passe de fraisage préalable à ladite passe corrigée.According to another advantageous characteristic of the method, the correction of the control setpoint is predefined during a milling pass prior to said corrected pass.

Pendant une passe de fraisage, on acquiert une grandeur représentative d'au moins une composante transversale de l'effort que subit le foret lors du fraisage, ce qui permet de définir la correction de la consigne de pilotage de la passe de fraisage corrigée.During a milling pass, a quantity representative of at least one transverse component of the force experienced by the drill during the milling is acquired, which makes it possible to define the correction of the control setpoint of the corrected milling pass.

Selon une autre caractéristique avantageuse du procédé, la consigne de pilotage est réalisée dynamiquement pendant ladite passe corrigée de fraisage.According to another advantageous feature of the method, the control setpoint is dynamically performed during said corrected milling pass.

La correction de la consigne peut ainsi être adaptée lors de la passe corrigée de fraisage en fonction de la composante transversale que subit le foret pour atteindre le plus précisément possible la cote souhaité en chaque point du contour du trou à réaliser.The correction of the setpoint can thus be adapted during the corrected milling pass as a function of the transverse component that the drill undergoes to reach as precisely as possible the desired dimension at each point of the contour of the hole to be made.

Selon une autre caractéristique avantageuse du procédé, la correction de la consigne de pilotage du déplacement transversal du foret est au moins en partie prédéfinie à partir de l'acquisition d'une grandeur directement ou indirectement représentative d'au moins une composante axiale de l'effort que subit le foret lors du perçage.According to another advantageous characteristic of the method, the correction of the steering setpoint of the transverse displacement of the drill is at least partly predefined from the acquisition of a quantity directly or indirectly representative of at least one axial component of the effort that the drill undergoes during drilling.

Il est ainsi possible dès l'étape de perçage et avant l'étape de fraisage de la lentille, de déterminer la consigne de pilotage à partir de la composante axiale de l'effort que subit le foret lors du perçage.It is thus possible from the piercing step and before the step of milling the lens, to determine the steering setpoint from the axial component of the force experienced by the drill during drilling.

DESCRIPTION DÉTAILLÉE D'UN EXEMPLE DE RÉALISATIONDETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT

La description qui va suivre en regard des dessins annexés d'un mode de réalisation, donné à titre d'exemple non limitatif, fera bien comprendre en quoi consiste l'invention et comment elle peut être réalisée.The following description with reference to the accompanying drawings of an embodiment, given by way of non-limiting example, will make it clear what the invention consists of and how it can be achieved.

Sur les dessins annexés :

  • la figure 1 est une vue d'une lentille percée parcontournement ;
  • la figure 2 est un graphique donnant le diamètre d'un trou percé en fonction de l'épaisseur de la lentille, en l'absence de toute correction de consigne de pilotage;
  • la figure 3 est un graphique représentant le diamètre du trou percé en fonction de l'épaisseur de la lentille, avec une correction de consigne de pilotage;
  • la figure 4 est une vue en perspective d'un dispositif de détourage et de perçage équipé d'un module de perçage;
  • la figure 5 est une vue partielle en perspective du dispositif de détourage et de perçage de la figure 4 montrant, sous un autre angle et à plus grande échelle, le module de perçage.
In the accompanying drawings:
  • the figure 1 is a view of a pierced lens punt;
  • the figure 2 is a graph giving the diameter of a pierced hole as a function of the thickness of the lens, in the absence of any control setpoint correction;
  • the figure 3 is a graph showing the diameter of the drilled hole as a function of the thickness of the lens, with a control setpoint correction;
  • the figure 4 is a perspective view of a trimming and drilling device equipped with a drilling module;
  • the figure 5 is a partial perspective view of the clipping and drilling device of the figure 4 showing, from another angle and on a larger scale, the drilling module.

A la figure 4 on a représenté un dispositif de détourage et de perçage 6 équipé d'un module de perçage 625.To the figure 4 there is shown a trimming and drilling device 6 equipped with a drilling module 625.

Moyens de détourageClipping means

La fonction de détourage du dispositif de détourage et de perçage 6 peut être réalisée sous la forme de toute machine de découpage ou d'enlèvement de matière adaptée à modifier le contour de la lentille ophtalmique pour l'adapter à celui du cadre ou "cercle" d'une monture sélectionnée. Une telle machine peut consister par exemple en une meuleuse, une machine de découpage au laser ou par jet d'eau, etc.The trimming function of the trimming and drilling device 6 can be performed in the form of any cutting or material removal machine adapted to modify the contour of the ophthalmic lens to match that of the frame or "circle" of a selected mount. Such a machine may consist for example of a grinder, a laser cutting machine or jet water, etc.

Comme le montre la figure 4, le dispositif de détourage comporte, de manière connue en soi, une meuleuse 610 automatique, communément dite numérique. Cette meuleuse comporte, en l'espèce, une bascule 611, qui est montée librement pivotante autour d'un premier axe A1, en pratique un axe horizontal, sur un châssis.As shown in figure 4 , the shaping device comprises, in a manner known per se, an automatic grinder 610, commonly called digital. This grinder comprises, in this case, a flip-flop 611, which is freely pivotally mounted about a first axis A1, in practice a horizontal axis, on a frame.

Pour l'immobilisation et l'entraînement en rotation d'une lentille ophtalmique à usiner, la meuleuse est équipée de moyens support aptes à serrer et à entraîner en rotation une lentille ophtalmique. Ces moyens support comprennent deux arbres de serrage et d'entraînement en rotation 612, 613. Ces deux arbres 612, 613 sont alignés l'un avec l'autre suivant un deuxième axe A2, appelé axe de blocage, parallèle au premier axe A1. Les deux arbres 612, 613 sont entraînés en rotation de façon synchrone par un moteur (non représenté), via un mécanisme d'entraînement commun (non représenté) embarqué sur la bascule 611. Ce mécanisme commun d'entraînement synchrone en rotation est de type courant, connu en lui-même.For the immobilization and the rotational drive of an ophthalmic lens to be machined, the grinder is equipped with support means able to clamp and rotate an ophthalmic lens. These support means comprise two shafts and rotation drive 612, 613. These two shafts 612, 613 are aligned with each other along a second axis A2, called locking pin, parallel to the first axis A1. The two shafts 612, 613 are rotated synchronously by a motor (not shown), via a common drive mechanism (not shown) embedded on the flip-flop 611. This common synchronous rotation drive mechanism is of type current, known in itself.

En variante, on pourra aussi prévoir d'entraîner les deux arbres par deux moteurs distincts synchronisés mécaniquement ou électroniquement.Alternatively, it will also be possible to drive the two shafts by two separate motors synchronized mechanically or electronically.

La rotation ROT des arbres 612, 613 est pilotée par un système électronique et informatique central (non représenté) tel qu'un microordinateur intégré ou un ensemble de circuits intégrés dédiés.The ROT rotation of the shafts 612, 613 is driven by a central electronic and computer system (not shown) such as an integrated microcomputer or a set of dedicated integrated circuits.

Chacun des arbres 612, 613 possède une extrémité libre qui fait face à l'autre et qui est équipée d'un nez de blocage (non représenté). Ces nez de blocage ne sont pas toujours fixés sur les arbres 612, 613. Ils sont en effet au préalable utilisés par des moyens de préhension (non représentés) pour bloquer la lentille avant d'être transférés au présent dispositif de détourage et de perçage 6 en restant en contact avec la lentille transférée.Each of the shafts 612, 613 has a free end which faces the other and is equipped with a locking nose (not shown). These locking noses are not always fixed on the shafts 612, 613. They are in fact previously used by gripping means (not shown) to lock the lens before being transferred to the present clipping and drilling device 6 by staying in contact with the transferred lens.

L'arbre 613 est mobile en translation suivant l'axe de blocage A2, en regard de l'autre arbre 612, pour réaliser le serrage en compression axiale de la lentille entre les deux nez de blocage. L'arbre 613 est commandé pour cette translation axiale par un moteur d'entraînement via un mécanisme d'actionnement (non représentés) piloté par le système électronique et informatique central. L'autre arbre 612 est fixe en translation suivant l'axe de blocage A2.The shaft 613 is movable in translation along the blocking axis A2, facing the other shaft 612, to effect the compression in axial compression of the lens between the two locking noses. The shaft 613 is controlled for this axial translation by a drive motor via an actuating mechanism (not shown) controlled by the central electronic and computer system. The other shaft 612 is fixed in translation along the blocking axis A2.

Le dispositif de détourage et de perçage 6 comporte, d'autre part, un foret d'usinage, ici un train d'au moins une meule 614, qui est calé en rotation sur un troisième axe A3 parallèle au premier axe A1, et qui est elle aussi dûment entraînée en rotation par un moteur non représenté.The trimming and drilling device 6 comprises, on the other hand, a machining drill, here a train of at least one grinding wheel 614, which is wedged in rotation on a third axis A3 parallel to the first axis A1, and which is also properly rotated by a motor not shown.

En pratique, la meuleuse 610 comporte un train de plusieurs meules 614 montées coaxialement sur le troisième axe A3, pour un ébauchage et une finition du débordage de la lentille ophtalmique à usiner. Ces différentes meules sont adaptées chacune au matériau de la lentille détourée et au type d'opération effectuée (ébauche, finition, matériau minéral ou synthétique, etc. ).In practice, the grinder 610 comprises a train of several grinding wheels 614 mounted coaxially on the third axis A3, for a roughing and finish of the edging of the ophthalmic lens to be machined. These different grinding wheels are each adapted to the material of the cut-out lens and the type of operation performed (roughing, finishing, mineral or synthetic material, etc.).

Le train de meule est rapporté sur un arbre commun d'axe A3 assurant leur entraînement en rotation lors de l'opération de débordage. Cet arbre commun, qui n'est pas visible sur les figures présentées, est commandé en rotation par un moteur électrique 620 piloté par le système électronique et informatique.The grinding wheel is attached to a common shaft of axis A3 ensuring their rotational drive during the edging operation. This common shaft, which is not visible in the figures shown, is rotated by an electric motor 620 driven by the electronic and computer system.

Le train de meules 614 est en outre mobile en translation suivant l'axe A3 et est commandé dans cette translation par une motorisation pilotée. Concrètement, l'ensemble du train de meules 614, de son arbre et de son moteur est porté par un chariot 621 qui est lui-même monté sur des glissières 622 solidaires du bâti pour coulisser suivant le troisième axe A3. Le mouvement de translation du chariot porte-meules 621 est appelé « transfert » et est noté TRA sur la figure 3. Ce transfert est commandé par un mécanisme d'entraînement motorisé (non représenté), tel qu'un système à vis et écrou ou crémaillère, piloté par le système électronique et informatique central.The wheel train 614 is also movable in translation along the axis A3 and is controlled in this translation by a drive motor. Concretely, the entire wheel train 614, its shaft and its motor is carried by a carriage 621 which is itself mounted on slides 622 secured to the frame for sliding along the third axis A3. The translational movement of the wheel trolley 621 is called "transfer" and is noted TRA on the figure 3 . This transfer is controlled by a motorized drive mechanism (not shown), such as a screw and nut or rack system, controlled by the central electronic and computer system.

Pour permettre un réglage dynamique de l'entraxe entre l'axe A3 des meules 614 et l'axe A2 de la lentille lors du débordage, on utilise la capacité de pivotement de la bascule 611 autour de l'axe A1. Ce pivotement provoque en effet un déplacement, ici sensiblement vertical, de la lentille enserrée entre les arbres 612, 613 qui rapproche ou éloigne la lentille des meules 614. Cette mobilité, qui permet de restituer la forme de débordage voulue et programmée dans de système électronique et informatique, est appelée restitution et est notée RES sur les figures. Cette mobilité de restitution RES est pilotée par le système électronique et informatique central.To allow a dynamic adjustment of the distance between the axis A3 of the grinding wheels 614 and the axis A2 of the lens during the edging, the pivoting capacity of the lever 611 about the axis A1 is used. This pivoting causes indeed a displacement, here substantially vertical, of the lens sandwiched between the shafts 612, 613 which brings the lens closer or away from the grinding wheels 614. This mobility, which makes it possible to restore the shape of the desired and programmed edging in an electronic system. and computer science, is called restitution and is noted RES in the figures. This RES restitution mobility is controlled by the central electronic and computer system.

Pour l'usinage de la lentille ophtalmique suivant un contour donné, il faut déplacer en conséquence une noix 617 le long du cinquième axe A5, sous le contrôle du moteur 619, pour commander le mouvement de restitution et, d'autre part, faire pivoter conjointement les arbres de support 612, 613 autour du deuxième axe A2, en pratique sous le contrôle du moteur qui les commande: Le mouvement de restitution transversale RES de la bascule 611 et le mouvement de rotation ROT des arbres 612, 613 de la lentille sont pilotés en coordination par un système électronique et informatique (non représenté), dûment programmé à cet effet, pour que tous les points du contour de la lentille ophtalmique soient successivement ramenés au bon diamètre.For the machining of the ophthalmic lens according to a given contour, it is necessary to move accordingly a nut 617 along the fifth axis A5, under the control of the motor 619, to control the restitution movement and, on the other hand, to rotate together the support shafts 612, 613 around the second axis A2, in practice under the control of the motor which controls them: The transverse restitution movement RES of the flip-flop 611 and the rotational movement ROT of the shafts 612, 613 of the lens are controlled in coordination by an electronic and computer system ( not shown), duly programmed for this purpose, so that all the points of the contour of the ophthalmic lens are successively reduced to the correct diameter.

La meuleuse illustrée par la figure 4 comporte de plus un module de finition 625 qui embarque des meulettes de chanfreinage et rainage 630, 631 montées sur un axe commun 632 et qui est mobile selon un degré de mobilité, suivant une direction sensiblement transversale à l'axe A2 des arbres 612, 613 de maintien de la lentille ainsi qu'à l'axe A5 de la restitution RES. Ce degré de mobilité est appelé escamotage et est noté ESC sur les figures.The grinder illustrated by the figure 4 further comprises a finishing module 625 which embeds chamfering and grooving grinders 630, 631 mounted on a common axis 632 and which is movable with a degree of mobility, in a direction substantially transverse to the axis A2 of the shafts 612, 613 maintaining the lens and the axis A5 of the restitution RES. This degree of mobility is called retraction and is noted ESC in the figures.

En l'espèce, cet escamotage consiste en un pivotement du module de finition 625 autour de l'axe A3. Concrètement, le module 625 est porté par un levier 626 solidaire d'un manchon tubulaire 627 monté sur le chariot 621 pour pivoter autour de l'axe A3. Pour la commande de son pivotement, le manchon 627 est pourvu, à son extrémité opposée au levier 626, d'une roue dentée 628 qui engrène avec un pignon (non visible aux figures) équipant l'arbre d'un moteur électrique 629 solidaire du chariot 621.In this case, this retraction consists of a pivoting of the finishing module 625 around the axis A3. Specifically, the module 625 is carried by a lever 626 integral with a tubular sleeve 627 mounted on the carriage 621 to rotate about the axis A3. For the control of its pivoting, the sleeve 627 is provided, at its end opposite the lever 626, a toothed wheel 628 which meshes with a pinion (not visible in the figures) fitted to the shaft of an electric motor 629 integral with the trolley 621.

On observe, en résumé, que les degrés de mobilité disponibles sur une telle meuleuse de détourage sont :

  • la rotation de la lentille permettant de faire tourner la lentille autour de son axe de maintien, qui est globalement normal au plan général de la lentille,
  • la restitution, consistant en une mobilité relative transversale de la lentille (c'est-à-dire dans le plan général de la lentille) par rapport aux meules, permettant de reproduire les différents rayons décrivant le contour de la forme souhaitée de la lentille,
  • le transfert, consistant en une mobilité relative axiale de la lentille (c'est-à-dire perpendiculairement au plan général de la lentille) par rapport aux meules, permettant de positionner en vis-à-vis la lentille et la meule de détourage choisie.
  • l'escamotage, consistant en une mobilité relative transversale, suivant une direction distincte de celle de la restitution, du module de finition par rapport à la lentille, permettant de mettre en position d'utilisation et de ranger le module de finition.
In summary, it can be observed that the degrees of mobility available on such a trimming machine are:
  • the rotation of the lens making it possible to rotate the lens around its holding axis, which is generally normal to the general plane of the lens,
  • restitution, consisting of a transverse relative mobility of the lens (that is to say in the general plane of the lens) with respect to the grinding wheels, making it possible to reproduce the different rays describing the contour of the desired shape of the lens,
  • the transfer, consisting of an axial relative mobility of the lens (that is to say perpendicularly to the general plane of the lens) relative to the grinding wheels, to position the lens and the chosen cutting wheel in facing relation .
  • the retraction, consisting of a transverse relative mobility, in a direction different from that of the restitution, of the finishing module with respect to the lens, to put in position of use and store the finishing module.

Moyens de perçageMeans of drilling

En qui concerne la fonction de perçage, le module 625 est pourvu d'une perceuse 635 dont la broche est équipée d'un mandrin de fixation d'un foret 637 selon un axe de perçage A6 (voir figure 5).With regard to the drilling function, the module 625 is provided with a drill 635 whose spindle is equipped with a drill attachment mandrel 637 along a drilling axis A6 (see figure 5 ).

La perceuse 635 est montée sur le module 625 pour pivoter autour d'un axe d'orientation A7 sensiblement transversal à l'axe A3 des meules 614 ainsi qu'à l'axe A5 de restitution et, partant, sensiblement parallèle à la direction d'escamotage ESC du module 625. L'axe de perçage A6 est ainsi orientable autour de l'axe d'orientation A7, c'est-à-dire dans un plan proche de la verticale. Ce pivotement d'orientation de la perceuse 635 est noté PIV sur la figure 4. Il s'agit du seul degré de mobilité dédié au perçage.The drill 635 is mounted on the module 625 so as to pivot about an axis of orientation A7 substantially transverse to the axis A3 of the grinding wheels 614 as well as to the axis A5 of restitution and, consequently, substantially parallel to the direction of rotation. ESC retraction of the module 625. The drilling axis A6 is thus orientable about the axis of orientation A7, that is to say in a plane close to the vertical. This pivoting orientation of the drill 635 is noted PIV on the figure 4 . This is the only degree of mobility dedicated to drilling.

L'intégration de la fonction de perçage au sein d'une machine de débordage implique que le foret soit convenablement positionné en regard de la position du trou à percer sur la lentille. Ce positionnement est réalisé au moyen de deux degrés de mobilité préexistants, indépendamment de la fonction de perçage, qui sont l'escamotage ESC d'une part et le transfert TRA d'autre part. Ces deux degrés de mobilité, d'escamotage et de transfert sont de surcroît utilisés pour régler l'orientation de l'axe de perçage A6 de la perceuse 635.The integration of the drilling function within an edging machine implies that the drill is properly positioned opposite the position of the hole to be drilled on the lens. This positioning is achieved by means of two pre-existing degrees of mobility, independently of the drilling function, which are the retraction ESC on the one hand and the transfer TRA on the other hand. These two degrees of mobility, retraction and transfer are furthermore used to adjust the orientation of the drilling axis A6 of drill 635.

Pour son montage pivotant sur le module 625, le corps 634 de la perceuse 635 possède un manche cylindrique d'axe A7 qui est reçu à pivotement dans un alésage correspondant de même axe A7 ménagé dans le corps du module 625. La perceuse 635 peut ainsi pivoter autour de l'axe d'orientation A7 sur une plage de positions angulaires correspondant à autant d'inclinaison de l'axe de perçage A6 par rapport à la lentille à percer lorsque le module 625 viendra en position de perçage. Cette plage de positions angulaires est délimitée physiquement par deux butées angulaires solidaires du corps du module 625.For its pivoting mounting on the module 625, the body 634 of the drill 635 has a cylindrical shaft A7 sleeve which is pivotally received in a corresponding bore of the same axis A7 formed in the body of the module 625. The drill 635 can thus pivoting about the axis of orientation A7 over a range of angular positions corresponding to the same inclination of the drilling axis A6 with respect to the lens to be pierced when the module 625 will come into the drilling position. This range of angular positions is physically delimited by two angular stops integral with the body of the module 625.

Dans l'exemple illustré, les moyens de réglage de l'orientation comportent, d'une part, un doigt 638 solidaire du corps 634 de la perceuse 635 et pourvu d'une extrémité sphérique 639 et, d'autre part, une platine 650 portant un chemin de came 651 et solidaire du bâti 601 de la meuleuse.In the example illustrated, the adjustment means of the orientation comprise, on the one hand, a finger 638 secured to the body 634 of the drill 635 and provided with a spherical end 639 and, on the other hand, a plate 650 carrying a cam path 651 and integral with the frame 601 of the grinder.

La platine 650 présente une face utile plane 658 qui est sensiblement perpendiculaire à la direction de transfert TRA, ou autrement dit, dans l'exemple illustré, aux axes A2 et A3. Comme les axes A2 et A3 sont ici horizontaux, la face utile 858 de la platine 650 est verticale. Lorsque le module 625 se trouve dans sa plage angulaire de réglage, la face utile 658 de la platine 650 est située en regard de l'extrémité 639 du doigt 638 de la perceuse 635. Le chemin de came de la platine 650 est constitué par une tranchée 651 ménagée en renfoncement de la face utile 658 de la platine 650.The plate 650 has a plane useful face 658 which is substantially perpendicular to the transfer direction TRA, or in other words, in the example shown, to the axes A2 and A3. As the axes A2 and A3 are here horizontal, the useful face 858 of the plate 650 is vertical. When the module 625 is in its angular range of adjustment, the useful face 658 of the plate 650 is located opposite the end 639 of the finger 638 of the drill 635. The cam path of the plate 650 is constituted by a trench 651 formed in recess of the useful face 658 of the plate 650.

En service, le réglage de l'inclinaison de l'axe de perçage A6 autour de l'axe d'orientation A7 s'effectue de façon automatique, sous le pilotage du systèmeIn operation, the adjustment of the inclination of the drilling axis A6 around the axis of orientation A7 takes place automatically, under the control of the system

électronique et informatique, en exploitant les mobilités de transfert TRA et d'escamotage ESC du module pour faire coopérer le doigt 638 de la perceuse avec la platine à came 650.electronics and computer, by exploiting the transfer mobilities TRA and retraction ESC of the module to cooperate the finger 638 of the drill with the cam plate 650.

Le dispositif de détourage et de perçage comporte enfin des moyens de mémorisation de la forme et de la dimension souhaitées d'un trou 700 de perçage de la lentille, encore appelé trou à percer, et de la position de ce trou sur la surface de la lentille. Ces moyens de mémorisation peuvent être constitués d'une mémoire réinscriptible et d'une interface (par exemple un clavier et un écran) permettant d'écrire dans cette mémoire.The trimming and drilling device finally comprises means for memorizing the desired shape and size of a drilling hole 700 of the lens, also called the hole to be drilled, and the position of this hole on the surface of the hole. lens. These storage means may consist of a rewritable memory and an interface (for example a keyboard and a screen) for writing in this memory.

Procédé de perçageDrilling process

Tout d'abord, la forme et la dimension souhaitées du trou 700 de perçage à réaliser dans la lentille ainsi que la position de ce trou de perçage sur la surface de la lentille, sont mémorisées par les moyens de mémorisation du dispositif de détourage et de perçage.Firstly, the desired shape and size of the drilling hole 700 to be made in the lens as well as the position of this drilling hole on the surface of the lens are stored by the storage means of the clipping device and drilling.

Lors du perçage, le système de traitement électronique 100 pilote en coordination appropriée les mobilités de transfert TRA du module de finition 625 portant le module de perçage, de restitution RES des arbres de serrage et d'entraînement en rotation 612, 613, d'escamotage ESC du module de finition 625 et éventuellement de rotation ROT de la lentille pour obtenir les mobilités relatives du foret par rapport à la lentille nécessaires à la réalisation du trou de perçage. Ces mobilités relatives comportent une mobilité d'avance relative du foret de perçage par rapport à la lentille suivant l'axe de rotation du foret et une mobilité de déplacement transversal du foret de perçage par rapport à son axe de perçage. Ici, la mobilité d'avance relative du foret de perçage par rapport à la lentille peut être obtenue par une mobilité composée par exemple à partir de la mobilité d'escamotage ESC du module de finition 625 et de la mobilité de transfert TRA du module de finition 625. En variante, la mobilité d'avance relative du foret de perçage par rapport à la lentille peut être obtenue au moyen d'une mobilité simple supplémentaire par déplacement du foret de perçage le long de son axe de perçage par rapport au module de finition 625.During the drilling, the electronic processing system 100 manages, in appropriate coordination, the transfer mobilities TRA of the finishing module 625 carrying the drilling, restitution module RES of the clamping and rotation shafts 612, 613, of retraction. ESC of the finisher 625 and optionally rotation ROT of the lens to obtain the relative mobilities of the drill relative to the lens necessary for the realization of the drilling hole. These relative mobilities comprise a relative advance mobility of the drill bit relative to the lens along the axis of rotation of the drill and a mobility of transverse displacement of the drill bit relative to its drilling axis. Here, the relative advance mobility of the drill bit relative to the lens can be obtained by a mobility composed for example from the retraction mobility ESC of the finishing module 625 and the transfer mobility TRA of the module Alternatively, the relative advance mobility of the drill bit relative to the lens can be achieved by means of additional simple mobility by moving the drill bit along its drilling axis relative to the drilling module. finish 625.

Pour débuter le perçage on perce la lentille au moyen du foret en un point d'origine PO, encore appelé point de départ de perçage. La position de ce point d'origine PO est choisie sensiblement au centre du trou. Dans le cas d'un trou oblong ce point d'origine est choisi comme étant le centre d'un des deux demi-cercles définissant le trou oblong.To begin drilling, the lens is drilled by means of the drill bit at a point of origin PO, also called the starting point of drilling. The position of this point of origin PO is chosen substantially in the center of the hole. In the case of an oblong hole this point of origin is chosen to be the center of one of the two semicircles defining the oblong hole.

On positionne le foret de perçage en vis-à-vis de la position d'origine du trou 700 à percer et on règle l'orientation du foret 637 en pilotant en coordination appropriée les mobilités de transfert TRA, de restitution RES et de rotation ROT de telle sorte que l'axe de perçage A6 soit sensiblement confondu avec la normale à la lentille au point d'origine PO considéré. Après avoir convenablement orienté le foret, on débute le perçage en ce point d'origine PO. Le foret est alors entraîné en rotation et déplacé en translation suivant l'axe de perçage A7, c'est-à-dire suivant sa mobilité d'avance, vers le point d'origine PO jusqu'à percer la lentille.The drilling drill is positioned opposite the original position of the hole 700 to be drilled and the orientation of the drill 637 is adjusted by coordinating control. appropriate transfer mobilities TRA, RES restitution and rotation ROT so that the drilling axis A6 is substantially coincident with the normal to the lens at the point of origin PO considered. After properly orienting the drill, it begins drilling at this point of origin PO. The drill is then rotated and moved in translation along the axis of drilling A7, that is to say according to its mobility in advance, to the point of origin PO until piercing the lens.

Le trou 700 à percer étant de diamètre supérieur au diamètre du foret et/ou de forme non circulaire, on met en oeuvre une méthode de perçage particulière, appelée perçage par contournement. Selon cette méthode, le foret 637, engagé dans la lentille, est déplacé transversalement par rapport à l'axe A6 de perçage. Le foret 637 est ainsi utilisé à la manière d'une fraise en étant déplacé de manière sensiblement circulaire pour enlever une profondeur donnée de matière, jusqu'à atteindre la cote souhaitée en tout point du contour du trou 700 à percer.Since the hole 700 to be drilled is of diameter greater than the diameter of the drill and / or of non-circular shape, a special drilling method, called bypass drilling, is used. According to this method, the drill 637, engaged in the lens, is moved transversely with respect to the drilling axis A6. The drill 637 is thus used in the manner of a milling cutter being moved in a substantially circular manner to remove a given depth of material, until reaching the desired dimension at any point in the contour of the hole 700 to be drilled.

La profondeur de matière enlevée correspond au rayon de matière enlevée suite à un déplacement du foret de manière sensiblement circulaire dans le plan transversal à son axe de perçage, c'est-à-dire sensiblement dans le plan tangent à la lentille passant par le point d'origine PO.The depth of material removed corresponds to the radius of material removed following a movement of the drill substantially circular in the plane transverse to its piercing axis, that is to say substantially in the plane tangent to the lens passing through the point original PO.

Ici, comme représenté sur la figure 1, le trou 700 à percer est un trou oblong. Pour réaliser ce trou oblong le déplacement du foret est piloté suivant une trajectoire spiroïdale comme représenté par les flèches de déplacement du foret sur la figure 1.Here, as represented on the figure 1 the hole 700 to be drilled is an oblong hole. To achieve this oblong hole the movement of the drill is controlled along a spiral path as represented by the arrows of movement of the drill on the figure 1 .

Le déplacement du foret 637 suivant cette trajectoire spiroïdale comprend tout d'abord une passe de fraisage initiale 701 selon laquelle le foret est déplacé de manière rectiligne sur la longueur L0 du trou 700 à réaliser. Cette passe de fraisage initiale 701 est réalisée en "pleine matière", c'est-à-dire que la profondeur de matière enlevée est égale au diamètre du foret.The displacement of the drill 637 along this spiral path firstly comprises an initial milling pass 701 in which the drill is moved rectilinearly along the length L0 of the hole 700 to be made. This initial milling pass 701 is made of "full material", that is to say that the depth of material removed is equal to the diameter of the drill.

Ensuite, le déplacement transversal du foret est piloté pour réaliser plusieurs passes de fraisage 701, 702, 703 suivant une trajectoire dont la forme correspond à la forme du trou souhaité mais de plus faible dimension. A chaque nouvelle passe de fraisage, la trajectoire du foret, tout en gardant la même forme, est élargie. Les trajectoires de ces passes de fraisage forment ainsi une spirale. Après plusieurs passes de fraisage, le foret se retrouve à proximité du contour souhaité du trou à réaliser. Le foret est alors piloté pour réaliser une passe de fraisage suivant une consigne de pilotage qui correspond directement à la forme et à la dimension souhaitées du trou de perçage.Then, the transverse displacement of the drill is controlled to perform several milling passes 701, 702, 703 along a path whose shape corresponds to the shape of the desired hole but of smaller size. With each new milling pass, the trajectory of the drill, while keeping the same shape, is enlarged. The paths of these milling passes thus form a spiral. After several milling passes, the drill is near the desired contour of the hole to be made. The drill is then driven to perform a milling pass following a control setpoint that corresponds directly to the desired shape and size of the drilling hole.

Sans l'invention, c'est-à-dire en l'absence de correction de consigne, bien que la consigne de pilotage corresponde directement à la forme et à la dimension souhaitées du trou de perçage, la dimension du trou résultant de cette passe de fraisage est inférieure à la dimension souhaitée du trou de perçage.Without the invention, that is to say in the absence of setpoint correction, although the control setpoint corresponds directly to the desired shape and size of the drilling hole, the hole size resulting from this milling pass is smaller than the desired size of the drilling hole.

Sur la figure 2 on a tracé un graphique sur lequel est rapporté le diamètre Dm d'un trou percé résultant d'une consigne de pilotage correspondant à un diamètre souhaité Dms en fonction de l'épaisseur Ep de la lentille au point de perçage, en l'absence de toute correction de consigne de pilotage. On peut observer sur cette figure 2 que, plus l'épaisseur Ep de la lentille au point de perçage est importante, plus l'écart entre le diamètre obtenu Dm du trou percé et le diamètre souhaité Dms du trou est important. En particulier, plus l'épaisseur Ep de la lentille au point de perçage est importante, plus le diamètre Dm du trou obtenu diminue par rapport au diamètre souhaité Dms de ce trou. Au-delà d'une certaine épaisseur, la valeur du diamètre obtenu du trou sort de l'intervalle de tolérance IT fixé.On the figure 2 a graph has been plotted on which is reported the diameter Dm of a drilled hole resulting from a control setpoint corresponding to a desired diameter Dms as a function of the thickness Ep of the lens at the piercing point, in the absence of any control setpoint correction. We can observe on this figure 2 that, the greater the thickness Ep of the lens at the point of drilling, the greater the difference between the obtained diameter Dm of the drilled hole and the desired diameter Dms of the hole is important. In particular, the greater the thickness Ep of the lens at the point of drilling, the greater the diameter Dm of the hole obtained decreases relative to the desired diameter Dms of this hole. Beyond a certain thickness, the value of the diameter obtained from the hole out of the IT tolerance range set.

Correction de la consigne du perçage par contournement, selon l'inventionCorrection of the instruction of the bypass boring, according to the invention

Ce procédé de correction permet d'obtenir la forme et la taille souhaitées du trou à percer selon un procédé de perçage par contournement, ou fraisage, tel que présenté ci-dessus.This correction method makes it possible to obtain the desired shape and size of the hole to be drilled according to a bypass or milling method, as presented above.

Selon un premier mode d'exécution, on réalise une correction de consigne du pilotage du déplacement transversal du foret en fonction de l'épaisseur au point de perçage de la lentille. La répartition des points sur la figure 2, donnant le diamètre obtenu Dm du trou en fonction de l'épaisseur Ep de la lentille au point de perçage, permet de déterminer une fonction de correction donnant la correction de consigne de pilotage à appliquer au déplacement transversal du foret suivant l'épaisseur de la lentille au point de perçage pour obtenir le diamètre souhaité Dms du trou.According to a first embodiment, a setpoint correction is made for controlling the transverse displacement of the drill as a function of the thickness at the piercing point of the lens. The distribution of points on the figure 2 , giving the obtained diameter Dm of the hole as a function of the thickness Ep of the lens at the piercing point, makes it possible to determine a correction function giving the control setpoint correction to be applied to the transverse displacement of the drill according to the thickness of the lens at the piercing point to obtain the desired diameter Dms of the hole.

La correction de la consigne de pilotage du déplacement transversal du foret de perçage 637 consiste en un élargissement de la dimension du trou à réaliser suivant une méthode prenant en compte l'épaisseur de la lentille. Autrement dit, cette correction de consigne de pilotage consiste à augmenter la profondeur de passe de manière à compenser l'écart observé entre la dimension obtenue et la dimension souhaitée du trou. Ici cette fonction de correction est sensiblement linéaire. Ainsi, pour que le foret puisse atteindre la cote souhaitée en chaque point du contour de la lentille, la consigne de pilotage requiert que le foret atteigne une cote plus profonde.The correction of the steering setpoint of the transverse displacement of the drill bit 637 consists in an enlargement of the size of the hole to be made according to a method taking into account the thickness of the lens. In other words, this control setpoint correction consists in increasing the depth of pass so as to compensate for the difference observed between the dimension obtained and the desired size of the hole. Here this correction function is substantially linear. Thus, so that the drill can reach the desired dimension at each point of the lens contour, the driving instruction requires that the drill reaches a deeper dimension.

Il est procédé à une passe de fraisage corrigée pour laquelle la consigne de pilotage du déplacement transversal du foret de perçage est corrigée suivant la fonction de correction citée ci-dessus, c'est-à-dire ici en fonction de l'épaisseur de la lentille. En appliquant cette correction de consigne selon l'épaisseur considérée au point de perçage, la valeur du diamètre obtenu est dans l'intervalle de tolérance donné, comme représenté sur le graphique de la figure 3.A corrected milling pass is carried out for which the instruction The steering of the transverse displacement of the drill bit is corrected according to the correction function mentioned above, that is to say here depending on the thickness of the lens. By applying this setpoint correction according to the thickness considered at the piercing point, the value of the diameter obtained is within the given tolerance interval, as represented on the graph of the figure 3 .

La correction de la consigne de pilotage du déplacement transversal du foret de perçage peut ainsi être obtenue au moyen de courbes de référence donnant le diamètre obtenu du trou en fonction d'un paramètre tel que l'épaisseur de la lentille au point de perçage. On peut également réaliser des abaques donnant directement la correction de la consigne de pilotage à appliquer.The correction of the control setpoint of the transverse displacement of the drill bit can thus be obtained by means of reference curves giving the obtained diameter of the hole as a function of a parameter such as the thickness of the lens at the piercing point. It is also possible to make abacuses giving directly the correction of the control setpoint to be applied.

Selon l'invention, on réalise une correction de consigne du pilotage du déplacement transversal du foret en fonction du matériau de la lentille. Pour cela, on réalise une courbe semblable à celle du premier mode de réalisation mais cette fois non pas en fonction de l'épaisseur, mais en fonction du matériau de la lentille et pour une épaisseur déterminée.According to the invention, a setpoint correction is made for controlling the transverse displacement of the drill as a function of the material of the lens. For this, a curve similar to that of the first embodiment is produced, but this time not according to the thickness, but as a function of the material of the lens and for a determined thickness.

Selon un deuxième mode d'exécution, on réalise une correction de consigne de pilotage en fonction de l'épaisseur de la lentille au point de perçage et en fonction du matériau de la lentille. Pour cela on peut établir pour différents matériaux des courbes donnant l'écart entre le diamètre obtenu et le diamètre souhaité en fonction de l'épaisseur (comme pour la courbe représentée sur la figure 1). À chacune de ces courbes correspond une fonction de correction telle que décrite ci-dessus. Il suffit alors d'appliquer aux consignes de pilotage du fraisage, la fonction de correction, interpolée ou non, correspondant au matériau de la lentille à percer ainsi qu'à l'épaisseur au point de perçage considéré.According to a second embodiment, a control setpoint correction is performed as a function of the thickness of the lens at the piercing point and as a function of the material of the lens. For this purpose it is possible to establish for different materials curves giving the difference between the diameter obtained and the desired diameter as a function of the thickness (as for the curve shown on FIG. figure 1 ). Each of these curves corresponds to a correction function as described above. It is then sufficient to apply to the milling control instructions, the correction function, interpolated or not, corresponding to the material of the lens to be drilled and the thickness at the piercing point considered.

Selon un troisième mode d'exécution, on réalise une correction de consigne de pilotage du fraisage en fonction des caractéristiques mécaniques du foret de perçage. Ces caractéristiques mécaniques peuvent être le diamètre et/ou le matériau du foret de perçage, ou encore d'autres caractéristiques mécaniques: La fonction de correction est obtenue d'une manière semblable aux modes de réalisation précédents, à partir d'une ou plusieurs courbes donnant le diamètre du trou obtenu en fonction d'une ou de plusieurs caractéristiques mécaniques du foret.According to a third embodiment, a milling control setpoint correction is made according to the mechanical characteristics of the drill bit. These mechanical characteristics can be the diameter and / or the material of the drill bit, or else other mechanical characteristics: The correction function is obtained in a manner similar to the previous embodiments, from one or more curves. giving the diameter of the hole obtained according to one or more mechanical characteristics of the drill.

Bien évidemment, ce troisième mode d'exécution peut être combiné avec l'un des modes d'exécution précédents. De manière préférentielle, la correction de consigne est alors réalisée à la fois en fonction de l'épaisseur au point de perçage de la lentille, en fonction du matériau de la lentille et en fonction des caractéristiques mécaniques du foret.Of course, this third embodiment can be combined with one of the previous modes of execution. Preferably, the target correction is then performed both as a function of the thickness at the piercing point of the lens, as a function of the material of the lens and as a function of mechanical characteristics of the drill.

On peut également corriger la consigne de pilotage du déplacement transversal du foret de perçage en fonction de l'avance et/ou de la profondeur de passe du fraisage. Comme précédemment, ces paramètres peuvent être combinés aux autres paramètres dont dépend la correction de consigne tels que l'épaisseur et/ ou le matériau de la lentille à percer, et/ou les caractéristiques mécaniques du foret.It is also possible to correct the steering setpoint for the transverse displacement of the drill bit according to the advance and / or the depth of the milling pass. As before, these parameters can be combined with the other parameters on which the setpoint correction depends such as the thickness and / or the material of the lens to be pierced, and / or the mechanical characteristics of the drill.

Il est aussi possible de prévoir dans chaque mode d'exécution décrit ci-dessus, de réaliser une ou plusieurs passes de fraisage non corrigées postérieures à la passe de fraisage corrigée et pour laquelle la consigne de pilotage du déplacement transversal du foret de perçage correspond directement à la forme et à la dimension souhaitées du trou de perçage.It is also possible to provide in each embodiment described above, to perform one or more uncorrected milling passes after the corrected milling pass and for which the control set of the transverse displacement of the drill bit corresponds directly. to the desired shape and size of the piercing hole.

Quel que soit le mode d'exécution décrit ci-dessus, on peut enfin prévoir que la correction de la consigne de pilotage du déplacement transversal du foret de perçage soit réalisée dynamiquement pendant le fraisage au moyen de l'acquisition d'une composante au moins de l'effort de fraisage par un capteur d'effort approprié. Cet effort de fraisage permet à partir d'une formule mathématique, qui peut être obtenue ou non empiriquement, d'en déduire un ou plusieurs paramètres dont dépend la fonction de correction, tel que l'épaisseur et/ou le matériau de la lentille, et/ou les caractéristiques mécaniques du foret. La consigne de pilotage est alors corrigée, compte tenu du ou des paramètre déduits.Whatever the embodiment described above, it is finally possible to provide for the correction of the control setpoint for the transverse displacement of the drill bit to be performed dynamically during milling by means of the acquisition of at least one component. the milling force by a suitable force sensor. This milling effort allows from a mathematical formula, which can be obtained or not empirically, to deduce one or more parameters on which depends the correction function, such as the thickness and / or the material of the lens, and / or the mechanical characteristics of the drill. The steering setpoint is then corrected, taking into account the parameter or parameters deduced.

Toujours quel que soit le mode d'exécution décrit ci-dessus, la correction de la consigne de pilotage du déplacement transversal du foret de perçage peut également être, au moins en partie, définie à partir de l'acquisition d'une composante au moins de l'effort de perçage (au point d'origine) par un capteur d'effort approprié. Comme précédemment, cet effort de perçage permet à partir d'une formule mathématique, obtenue ou non empiriquement, d'en déduire un ou plusieurs paramètre dont dépend la fonction de correction, et ainsi de corriger la consigne de pilotage.Still whatever the embodiment described above, the correction of the driving instruction for the transverse displacement of the drill bit can also be at least partially defined from the acquisition of at least one component. the drilling effort (at the point of origin) by a suitable force sensor. As before, this drilling effort makes it possible, from a mathematical formula, obtained or not empirically, to deduce from it one or more parameters on which the correction function depends, and thus to correct the driving instruction.

La profondeur de matière enlevée par le foret durant les passes de fraisage peut être modifiée en adaptant la consigne de pilotage suivant le matériau de la lentille usinée et/ou l'épaisseur de la partie fraisée de lentille, et/ou les caractéristiques mécaniques du foret, et/ou l'avance du foret.The depth of material removed by the drill during the milling passes can be modified by adapting the control setpoint according to the material of the machined lens and / or the thickness of the milled lens portion, and / or the mechanical characteristics of the drill bit , and / or the advance of the drill.

Bien entendu, plus l'épaisseur, et/ou la dureté matériau de la lentille est importante, plus la correction apportée est importante. De même, plus les caractéristiques mécaniques du foret sont faibles, c'est-à-dire plus la flèche du foret (résultant d'un effort de flexion sur le foret) est importante plus la correction de consigne est importante. Enfin, plus l'avance du foret est importante, plus la correction apportée à la consigne de pilotage est importante.Of course, the greater the thickness, and / or the material hardness of the lens, the greater the correction made. Likewise, the lower the mechanical characteristics of the drill, that is, the greater the deflection of the drill (resulting from a bending force on the drill), the greater the correction. deposit is important. Finally, the greater the advance of the drill, the greater the correction made to the driving instruction.

Selon un quatrième mode d'exécution, on peut prévoir que pour la passe de fraisage corrigée la consigne de pilotage du déplacement transversal du foret est corrigée en fonction d'une grandeur représentative d'au moins une composante transversale de l'effort que subit ledit foret lors du fraisage la lentille.According to a fourth embodiment, it can be provided that for the corrected milling pass, the steering setpoint for the transverse displacement of the drill bit is corrected as a function of a magnitude representative of at least one transverse component of the force experienced by said drill. drill when milling the lens.

Cette grandeur mesurée peut être directement la composante transversale de l'effort que subit le foret. On pourra utiliser pour déterminer cette composante une jauge de contrainte par exemple. La grandeur mesurée peut également être l'intensité du courant dans le moteur dont la valeur varie en fonction de l'effort transversal auquel est soumis le foret. On peut aussi envisager de mesurer les variations de l'avance du foret dans le cas de l'application d'un effort de couple prédéfini et d'en déduire la composante transversale de l'effort que subit le foret. La déduction de la composante transversale de l'effort que subit le foret peut être réalisée à partir de courbes ou d'abaques de référence obtenues par exemple empiriquement. La correction de consigne de pilotage est alors déterminée à partir de cette composante transversale (par exemple au moyen de courbes ou d'abaques de référence).This measured quantity can be directly the transversal component of the effort that the forest undergoes. One can use to determine this component a strain gauge for example. The magnitude measured may also be the intensity of the current in the motor whose value varies as a function of the transverse force to which the drill is subjected. It is also possible to measure the variations in the advance of the drill in the case of the application of a predefined torque force and to deduce the transverse component of the force experienced by the drill. The deduction of the transverse component of the force experienced by the drill can be made from curves or reference charts obtained for example empirically. The control setpoint correction is then determined from this transverse component (for example by means of curves or reference charts).

En particulier, la correction de la consigne de pilotage est prédéfinie pendant une passe de fraisage préalable à ladite passe corrigée. On peut également, pour plus de précision, déterminer la consigne de pilotage dynamiquement pendant ladite passe corrigée de fraisage.In particular, the correction of the control setpoint is predefined during a milling pass prior to said corrected pass. It is also possible, for greater precision, to determine the driving instruction dynamically during said corrected milling pass.

Comme précédemment, cette correction de consigne à appliquer correspond à un élargissement de la dimension du trou pour compenser la diminution de dimension obtenue du fait des efforts de flexion que subit le foret.As before, this setpoint correction to be applied corresponds to an enlargement of the size of the hole to compensate for the decrease in size obtained due to the bending forces experienced by the drill.

Selon un cinquième mode d'exécution, la correction de la consigne de pilotage du déplacement transversal du foret est prédéfinie à partir de l'acquisition d'une grandeur représentative d'une composante axiale de l'effort que subit le foret lors du perçage. Comme précédemment, cette grandeur peut être directement la composante axiale elle-même ou encore, indirectement, l'intensité du moteur et/ou l'avance du foret dont on peut déduire ladite composante axiale de l'effort que subit le foret. La déduction de la composante axiale de l'effort que subit le foret peut être réalisée à partir de courbes ou d'abaques de référence obtenues par exemple empiriquement. La correction de consigne de pilotage est alors déterminée à partir de cette composante axiale (par exemple au moyen de courbes ou d'abaques de référence). Il est ainsi possible dès l'étape de perçage et avant l'étape de fraisage de la lentille, de déterminer la consigne de pilotage à partir de la composante axiale de l'effort que subit le foret lors du perçage.According to a fifth embodiment, the correction of the steering setpoint of the transverse displacement of the drill is predefined from the acquisition of a magnitude representative of an axial component of the force experienced by the drill during drilling. As previously, this magnitude can be directly the axial component itself or, indirectly, the intensity of the motor and / or the advance of the drill from which one can deduce said axial component of the force experienced by the drill. The deduction of the axial component of the force experienced by the drill can be performed from curves or reference charts obtained for example empirically. The control setpoint correction is then determined from this axial component (for example by means of curves or reference charts). It is thus possible from the piercing step and before the step of milling the lens, to determine the control setpoint to from the axial component of the effort that the drill undergoes during drilling.

Enfin, une fois obtenues la dimension et la forme souhaitées du trou, le foret est déplacé à vide, c'est-à-dire sans enlèvement de matière, jusqu'au point d'origine de manière à réaliser une trajectoire fermée.Finally, once the desired size and shape of the hole is obtained, the drill is moved empty, that is to say without removal of material, to the point of origin so as to achieve a closed trajectory.

Ici, le foret a un diamètre compris entre 0.8 mm et 1mm. En variante, ce foret peut être remplacé par une fraise.Here, the drill has a diameter of between 0.8 mm and 1mm. Alternatively, this drill can be replaced by a bur.

Ici le trou est oblong, mais de manière générale le procédé de perçage s'applique à toutes les formes et toutes les dimensions de trou, par exemple un trou circulaire de diamètre plus important que celui du foret. Quelles que soient les caractéristiques du trou à réaliser, l'étape de fraisage consiste à réaliser des passes suivant une trajectoire proche de la forme souhaitée du trou, en augmentant au cours des passes la dimension de la forme définie par la trajectoire, suivant un pas dépendant de la profondeur de matière à enlever à chaque passe, jusqu'à atteindre la dimension souhaitée du trou.Here the hole is oblong, but in general the drilling method applies to all shapes and sizes of hole, for example a circular hole of larger diameter than that of the drill. Whatever the characteristics of the hole to be made, the milling step consists of making passes along a path close to the desired shape of the hole, increasing during the passes the dimension of the shape defined by the trajectory, following a step depending on the depth of material to be removed at each pass, until reaching the desired size of the hole.

Claims (12)

  1. A method of drilling an ophthalmic lens, the method comprising the following successive steps:
    · storing the shape and the size desired for a drill hole (700) in the lens and the position of this hole (700) on the surface of the lens;
    · positioning a drill bit (637) facing the position stored for the hole (700) to be drilled;
    · drilling the lens by means of the drill bit (637) having freedom to move relative to the lens in simple or compound manner in advance along the axis of rotation of the drill bill (637); and then
    · milling by causing the drill bit (637) that is engaged in the lens to move transversely in compliance with a setpoint for controlling the transverse movement as a function of the shape and size desired for the drill hole (700);
    the method being characterized in that the milling step includes at least one corrected milling pass for which the setpoint for controlling the transverse movement of the drill bit (637) is corrected, the correction to the setpoint for controlling the transverse movement of the drill bit (637) consisting in enlarging the desired size of the hole (700) as a function at least of the material of the lens in order to compensate for bending of the drill bit.
  2. A method of drilling according to the preceding claim, wherein the setpoint for controlling the transverse movement of the drill bit (637) is corrected as a function of a mechanical and/or geometrical characteristic of the lens.
  3. A method of drilling according to the preceding claim, wherein the setpoint for controlling the transverse movement of the drill bit (637) is corrected as a function of at least the thickness of the lens.
  4. A method of drilling according to any preceding claim, wherein the setpoint for controlling the transverse movement of the drill bit (637) is corrected as a function of at least a mechanical and/or geometrical characteristic of the drill bit (637).
  5. A method of drilling according to any preceding claim, wherein the setpoint for controlling the transverse movement of the drill bit (637) is corrected as a function of the advance and/or of the depth of cut of the milling.
  6. A method of drilling according to any preceding claim, wherein the setpoint for controlling the transverse movement of the drill bit (637) is corrected by means of reference curves or charts.
  7. A method of drilling according to any preceding claim, wherein the milling step includes one or more non-corrected milling passes after the corrected milling pass and during which the setpoint for controlling the transverse movement of the drill bit (637) corresponds directly to the desired shape and size of the drill hole (700).
  8. A method of drilling a lens according to any preceding claim, wherein the setpoint for controlling the transverse movement of the drill bit (637) is corrected beforehand, or else dynamically as a function of a magnitude that is directly or indirectly representative of at least one transverse or axial component of the force to which said drill bit is subjected during milling or drilling of the lens.
  9. A method of drilling according to the preceding claim, characterized in that the correction of the setpoint for controlling the transverse movement of the drill bit (637) is defined at least in part on the basis of acquiring a magnitude that is directly or indirectly representative of at least one transverse component of the force to which the drill bit is subjected during drilling.
  10. A method of drilling according to the preceding claim, characterized in that the control setpoint correction is predefined during a milling pass prior to said corrected pass.
  11. A method of drilling according to claim 10, characterized in that the control setpoint correction is performed dynamically during said corrected milling pass.
  12. A method of drilling according to claim 9, characterized in that the correction of the setpoint for controlling the transverse movement of the drill bit (637) is predefined at least in part on the basis of acquiring a magnitude that is directly or indirectly representative of at least one axial component of the force to which the drill bit is subjected during drilling.
EP07731085.2A 2006-03-15 2007-03-05 Method for drilling an ophthalmic lens to obtain the desired shape and dimension of a hole to be drilled in said lens Active EP1993797B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR0602267A FR2898527B1 (en) 2006-03-15 2006-03-15 METHOD OF DRILLING AN OPHTHALMIC LENS TO OBTAIN THE DESIRED SHAPE AND SIZE OF A HOLE TO BE PUNCHED IN THE LENS
PCT/FR2007/000386 WO2007104844A1 (en) 2006-03-15 2007-03-05 Method for drilling an ophthalmic lens to obtain the desired shape and dimension of a hole to be drilled in said lens

Publications (2)

Publication Number Publication Date
EP1993797A1 EP1993797A1 (en) 2008-11-26
EP1993797B1 true EP1993797B1 (en) 2014-05-07

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EP (1) EP1993797B1 (en)
FR (1) FR2898527B1 (en)
WO (1) WO2007104844A1 (en)

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Publication number Priority date Publication date Assignee Title
FR3003488B1 (en) * 2013-03-22 2015-03-27 Essilor Int METHOD OF DRILLING AN OPHTHALMIC LENS ACCORDING TO A HELICOIDAL OR PSEUDO-HELICOIDAL TRACK AND DRILLING DEVICE THEREFOR
CN114589758B (en) * 2022-03-21 2022-10-04 广州市博泰光学科技有限公司 Electrified helmet lens drilling equipment and application method thereof

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FR2306790A1 (en) * 1975-04-10 1976-11-05 Renault Automatic control of milling machine head - has pneumatic transducers on head and workpiece
GB1510299A (en) * 1975-07-07 1978-05-10 Verkstadstek Ab Method for adaptive control of machining operations
JPH10244440A (en) * 1997-03-05 1998-09-14 Toshiba Mach Co Ltd Main spindle end displacement correction device for machine tool
JP4194192B2 (en) * 1999-10-07 2008-12-10 株式会社ニデック Ball shape measuring device
JP3916445B2 (en) * 2001-11-08 2007-05-16 株式会社ニデック Eyeglass lens processing equipment
DE10312025A1 (en) * 2003-03-18 2004-10-07 Delta-X GmbH Ingenieurgesellschaft Gesellschaft für Strukturanalyse Position control error compensation method for machine, involves compensation mechanism for deformations of processing machines with continuously measuring circuit utilized on basis of finite element method computation

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Publication number Publication date
FR2898527B1 (en) 2009-01-16
EP1993797A1 (en) 2008-11-26
FR2898527A1 (en) 2007-09-21
WO2007104844A1 (en) 2007-09-20

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