EP0819967A1 - Contour reading device for a spectacles rim, sensor for the same, and application to the edging of the lens to be mounted - Google Patents

Abstract

The method involves measuring the shape of the inner surface (10) of a spectacle lens rim (11). This is to produce the correct shape for the lens edge to fit it makes use of a mobile feeler (12) with its positions recorded in a co-ordinate system. The feeler head (15) is used to scan the inner surface of the lens rim between two or more points on at least one side of the rim recess. The lens rim recess has a dihedral cross-section the feeler head is used to scan sufficient points on its surface to allow its shape to be reproduced from the co-ordinates obtained. The feeler used for the procedure can be a contact feeler with interchangeable heads, e.g. spherical in shape.

Description

The present invention relates in general to the contour reading which is usually carried out on the circles or surrounds of a spectacle frame in order to adapt to these the spectacle lenses which are to be mounted therein.

This contour reading is commonly done on a device equipped with an appropriate sensor or probe.

An outline reading device of this type is for example described in the French patent which, filed on October 6, 1989 under No 89 13 079, was published under No 2 652 893.

In this French patent, the spectacle frame on which it is to be carried out a contour reading is kept fixed, and the probe, which comprises, at the end of a rod, a head to be inserted in the bezel of the circle or entourage concerned. , is itself mounted mobile, and it is carried out a systematic location of its position in a determined coordinate system.

In this case, this location involves, on the one hand, polar coordinates, in a plane perpendicular to the probe rod, and, on the other hand, an altitude, perpendicular to this plane, to take account of the meniscus of the circles or entourages of the most common spectacle frames.

To date, and this is the case in the French patent mentioned above, the contour reading carried out essentially relates to the circumferential contour of the circle or surrounding of spectacle frame scrutinized.

However, no account is taken of the very profile of the bezel of this circle or surrounding, that is to say of the cross section of this bezel.

This cross section can be compared to that of a dihedral; it can also be any, other than that of a dihedral, for example half-round; moreover, in practice, from one spectacle frame to another, there is a significant diversity between the cross sections of the bezels according to the manufacturers.

Having regard, moreover, to the inevitable manufacturing tolerances of the grinding wheels used for cutting the corresponding bead on the edge a spectacle lens, traditionally designated by a bevel even when its section has a shape other than that of a dihedral, as well as to the wear of which such a grinding wheel is just as inevitably the object over time, It is not uncommon to observe, between the cross section of the bevel of a spectacle lens and that of the bezel of the circle or entourage of spectacle frame in which it must be mounted, discrepancies sufficiently large to compromise the suitable maintenance of this spectacle lens in this circle or surrounding of spectacle frame.

It therefore appears desirable, when cutting a bevel on the edge of a spectacle lens, to take into account, at best, the actual cross section of the bezel of the circle or frame of spectacle frame in which this spectacle lens must be mounted.

In European patent application No. O 583 915, the value of the opening angle of the cross section, here in the form of a dihedral, is accepted as known.

The present invention firstly relates to a method for the effective reading of this cross section; it also relates to a probe specific to the implementation of this process.

The method according to the invention is generally characterized in that, having a movable probe whose position can be identified in a given coordinate system, this probe is brought to the right of the bezel, by successively aiming by the head of this probe at least two points on at least one of the sides of this bezel different from each other, and the coordinates of these points are deduced. The section of the bezel can be arbitrary, here we mean by flank each of the walls of the bezel located on either side, axially, of the bottom proper of the bezel.

In the case where the cross-section of the bezel is a dihedral, it is understood that it may suffice to have the probe head aim two points of one of the flanks to deduce therefrom, from the coordinates of these two points, the slope of this flank.

When the probe available has, conventionally, for the aiming of the bezel, an intangible head, that is to say a head of determined geometry, action is taken in isolation on one of the sides of the bezel, without interference with the other of these flanks, and either we extrapolate, by symmetry, for the other flank, the reading taken, or we then intervene on this other flank in the same way as for the first.

As a variant, when the probe available has an interchangeable head for aiming the bezel, the two sides of the bezel are operated simultaneously with a first head, and then the same is done with a second head of a caliber different from that of the first.

In all cases, whatever the shape of the section of the bezel, and in addition to the usual measurements relating to the circumferential outline of the circle or surrounding of spectacle frame scrutinized, the measurement carried out according to the invention very simply makes it possible to determine the section of the bezel of this circle or of the frame of a spectacle frame, at at least one point thereof.

Another object of the invention is the application of the above method to the overflowing of the glass intended to be mounted in said bezel whose cross section has been raised. It is therefore possible, therefore, to completely reconstruct the fitting of the lens in the spectacle frame and thus to be informed about the position, on the one hand, of the points of contact between the bevel of the lens and the sides of the lens. bezel of the frame and, on the other hand, of the top of the bevel.

More precisely, the reconstitution of the casing of the glass is obtained by bringing, graphically and / or numerically, the section of the bezel and that of the grinding stone intended to overflow the glass, these two sections being of course on the same scale; the section of the grinding wheel is obtained by conventional means, such as profile projector, dimensional machine or the like. The close position where the section of the grinding wheel touches the section of the bezel corresponds to the simulated positioning of the lens in the frame, which makes it possible to know the position of the top of the bevel relative to the bezel; consequently, the instructions to be given to the grinding wheel for overflowing the glass are obtained by correcting the reading relating to the circumferential contour of the bezel taking account of this relative position of the apex of the bevel.

• la figure 1 est une vue en coupe transversale d'un cercle ou entourage de monture de lunettes, avec, en élévation, en regard de celui-ci, un palpeur susceptible d'entrer en son contact ;
• les figures 2A et 2B sont des vues qui, déduites de celle de la figure 1, illustrent deux phases successives de mise en oeuvre du procédé suivant l'invention pour le relevé de la pente d'un des flancs de ce drageoir ;
• les figures 3A et 3B sont des vues analogues à celles des figures 2A et 2B, pour le relevé de la pente de l'autre des flancs du drageoir concerné ;
• les figures 4 et 5 sont des vues analogues à celles des figures 2A, 2B, 3A, 3B, pour une intervention simultanée sur les deux flancs du drageoir à l'aide d'un palpeur suivant l'invention ;
• la figure 6 est, de manière éclatée, et avec un arrachement local, une vue d'une variante de réalisation de ce palpeur ;
• les figures 7 et 8 illustrent schématiquement l'application du procédé au débordage d'un verre, le palpeur étant du type de celui des figures 1 à 3B ;
• la figure 9 est un schéma analogue à celui de la figure 7, le palpeur étant du type de celui des figures 4 et 5, ou 6.

The characteristics and advantages of the invention will become apparent from the description which follows, by way of example, with reference to the appended schematic drawings in which:

• Figure 1 is a cross-sectional view of a circle or entourage of spectacle frame, with, in elevation, facing it, a probe capable of coming into contact;
• FIGS. 2A and 2B are views which, deduced from that of FIG. 1, illustrate two successive phases of implementation of the method according to the invention for recording the slope of one of the sides of this bezel;
• FIGS. 3A and 3B are views similar to those of FIGS. 2A and 2B, for recording the slope of the other of the sides of the bezel concerned;
• Figures 4 and 5 are views similar to those of Figures 2A, 2B, 3A, 3B, for a simultaneous intervention on the two sides of the bezel using a probe according to the invention;
• Figure 6 is an exploded view, with a local cutaway, a view of an alternative embodiment of this probe;
• Figures 7 and 8 schematically illustrate the application of the method to the overflow of a glass, the probe being of the type of that of Figures 1 to 3B;
• FIG. 9 is a diagram similar to that of FIG. 7, the feeler being of the type of that of FIGS. 4 and 5, or 6.

In Figure 1, we recognize, in section, the cross section of the bezel 10 of a circle or surround 11 of any spectacle frame not entirely visible, the cut in question being made at any point of this circle or surround 11, and, in elevation, the terminal part a feeler 12, which itself belongs to any contour reading device also not shown.

In what follows, for the convenience of the description, for determining the points of the scanned bezel, a contact probe is used so that the probe head is "carried" on said points; it goes without saying that these points can be determined using a contactless probe, for example with an optical head.

As is known, the bezel 10, the cross section of which it is to raise, forms a groove along the internal periphery of the circle or surround 11.

In the embodiment shown, it has, in cross section, a dihedral profile, having, obliquely, two flanks 13, 13 ', which overlap each other inwards at an angle of opening A.

The probe 12, for its part, comprises a rod 14, which extends substantially perpendicular to the plane of the circle or surrounding 11, and, in cantilever on this rod 14, in practice at the upper end thereof, a head 15 by which it is adapted to engage in the bezel 10, for contact therewith.

In the embodiment shown in FIG. 1, this head 15 is intangible, insofar as, permanently connected to the rod 14, it has a well-defined geometry and, therefore, a size that is also well-determined.

For example, and as shown, it is a flat palette, which, perpendicular to the rod 14, is cut in the style of a style.

While, in the contour reading device used, the spectacle frame to which the circle or entourage 11 belongs is fixed, being for example clamped between jaws suitable for maintaining it, the probe 12 is itself mobile.

To do this, it is linked, by its rod 14, to a drive mechanism belonging to this contour reading device.

The corresponding provisions are well known in themselves, in particular by the French patent No 89 13 079 mentioned above, and, not belonging specifically to the present invention, they will not be described in more detail here.

It will suffice to indicate that, in the contour reading device in question, the position of the probe 12 can at any time be identified in a given coordinate system.

For example, and as shown diagrammatically in FIG. 1, the probe 12 is, on the one hand, movable in a plane P, with respect to which the plane along which extends the spectacle frame to which the circle belongs or surround 11 is substantially parallel, and, on the other hand, movable perpendicular to this plane P, along the axis of its rod 14, as shown schematically by a double arrow F1 in FIG. 1.

In the plane P, the position of the probe 12 is, for example, identified in polar coordinates RT, and this is the case in the contour reading device which is the subject of French patent No 89 13 079.

Perpendicular to the plane P, the position of the probe 12 is identified by its altitude Z.

Optionally, and as shown diagrammatically by a double arrow F2 in FIG. 1, the probe 12 can also be mounted to rotate around the axis of its rod 14, for controlling the orientation of its head 15.

According to the invention, for reading the cross section of the bezel 10, the probe 12 is generally brought to the bottom of the bezel 10, by successively bringing the head 15 of this probe 12 to two points P1, P2, P'1, P'2 of at least one of the sides 13, 13 'of this bezel 10 different from each other, and the coordinates of these points P1, P2, P'1, P' are deduced 2 the slope of this flank 13, 13 '.

When, as shown in FIG. 1, the feeler 12 which is available has, for contact with the bezel 10, an intangible head 15, one intervenes in isolation on one of the sides 13, 13 ′ of the bezel 10, without interference with the other of these sides.

For example, and as shown diagrammatically in FIGS. 2A and 2B, the probe 12 is first brought into contact with the flank 13 by its head 15 at a point P1 of this flank 13 relatively close to the bottom of the bezel 10, FIG. 2A, then, the probe 12 thus being in contact by this head 15 with this flank 13, it is made to slide in contact with this flank 13 to a point P2 thereof relatively close to the outlet of the bezel 10, such that shown diagrammatically by arrow F3 in FIG. 2B.

The coordinates, duly noted, of the points P1, P2, give, by an elementary calculation, the slope of the flank 13.

As a first approximation, it is possible to extrapolate, by symmetry, for the flank 13 ', the slope value thus noted for the flank 13.

But, if desired, and as shown diagrammatically in FIGS. 3A and 3B, it is also possible, then, to intervene on this flank 13 'according to a process of the same type as the previous one.

For example, and as shown, the probe 12 is first of all carried by its head 15 on the flank 13 'at a point P'1 thereof relatively close to the outlet of the bezel 10, FIG. 3A, then , the probe 12 thus being in contact by this head 15 with this flank 13 ', it is made to slide along this flank 13' to a point P'2 thereof relatively close to the bottom of the bezel 10, as as shown schematically by the arrow F'3 in FIG. 3B.

In FIGS. 4 to 6, it is proposed, as a variant, according to the invention, to use a feeler 12 having, for contact with the bezel 10, an interchangeable head 15A, 15B.

The probe 12 can thus comprise, associated with the same rod 14, at least two heads 15A, 15B of different calibers.

In the embodiment shown in Figures 4 and 5, these two heads 15A, 15B are each respectively arranged permanently at the two ends of a crosspiece 16, which, carried by the rod 14, for example at its upper end, as shown, extends on either side of this rod 14, substantially perpendicular to the latter.

In addition, in this embodiment, the two heads 15A, 15B are spherical heads, with radii RA, RB different.

Anyway, with such an interchangeable head 15A, 15B, it is advantageously possible to intervene simultaneously on the two sides 13, 13 'of the bezel 10.

For example, in a first step, FIG. 4, one thus intervenes simultaneously on the two sides 13, 13 ′ of the bezel 10 with a first head 15A, which makes it possible to note the coordinates of a point P1 on the side 13 of this bezel 10 and the coordinates of a point P'2 on the side 13 'thereof, and, after reversing the probe 12, the procedure is then the same with a second head 15B, of caliber different from that of the first, which makes it possible to note the coordinates of a point P2 on the side 13 of the bezel 10 and the coordinates of a point P'1 on the side 13 'of the latter.

In the variant of implementation shown in FIG. 6, each of the heads 15A, 15B is carried by an individual endpiece 18A, 18B by which it is adapted to be attached removably to the rod 14.

For example, and as shown, the tip 18A, 18B is of the same type for the two heads 15A, 15B, and it is a tip 18A, 18B suitable for cooperating in fitting with a tip 19 provided so complementary to this effect on the rod 14.

In the embodiment shown, the end piece 18A, 18B of the rods 15A, 15B is a male end piece, while the end piece 19 of the rod 14 is a female end piece, but, of course, a reverse arrangement can be adopted.

In the examples which have just been described, the section of the bezel 10 is in the form of a dihedral; it will be readily understood that the invention applies regardless of the shape of the section of the bezel; when it is not in the form of a dihedral, the coordinates of several points, a hundred by example, are necessary to obtain a good representation of said section.

We will now describe an application of the method according to the invention to the overflowing of glasses.

Figures 7 and 8 show the application of the method in which the probe is of the type described in connection with Figures 1 to 3B.

In FIG. 7, the bezel 10, of the circle or surrounding 11, is shown, the cross section of which, here the flanks 13, 13 ′ in the form of a dihedron, was determined by the above method using the probe 12 ; this is at the bottom of the bezel, its head 15 touching the sides 13, 13 'in Po, P'o, respectively, and is at a distance from the bottom 21 proper, junction line of the sides 13, 13' of the bezel 10 ; it is in this position that the probe 12 is moved parallel to the plane P in order to raise the circumferential contour of the circle or frame surround, in fact a homothetic image Co of the bottom 21 of the bezel 10, partially visible in plan in FIG. 8 which is a top view with respect to FIG. 7, said image Co being produced from the readings of the probe, here the coordinates of the points of contact of the probe 12 with the sides 13, 13 ′ of the bezel 10.

FIG. 7 also shows the section 30 of the grinding wheel intended to overflow the glass to be associated with the bezel 10, this section 30 being on the same scale as that of the bezel 10, these two sections having been brought together one of the other until contact so that the mounting of the glass in the bezel 10 is thus simulated, the section of the grinding wheel having of course a shape strictly complementary to that of the bevel of the glass.

We see that the top 31 of section 30, which in fact represents the bottom of the groove of the grinding wheel and the bevel of the cut glass, is at a distance 40 from Co. It will therefore suffice to take this distance or offset into account to define the contour 31, FIG. 8, to be given to the glass for its correct mounting in the bezel 10, which contour 31 giving the perimeter of the glass.

Of course, this offset can also be corrected for a functional clearance, if desired, for example to limit or eliminate stresses during the mounting of the glass, in particular if the latter is a mineral glass.

FIG. 9 shows an application similar to that which has just been described, but in the case where the probe is of the spherical head type, such as for example the probe 15A of FIGS. 4 to 6. Here, the data of the probe lead to the curve 110 ′, place of the points C100 corresponding to each position of the center of the sphere 15A when the probe scans the bezel whose sides are therefore found to be the envelope of the circular sections of said sphere.

As before, the approximation of the section 110 of the bezel and that of the grinding wheel 130 gives the difference 140 between the image Co, here the point of the probe closest to the bottom 121 of the bezel, and the top 131 of the bevel of the glass. cut.

The present invention is not limited moreover to the embodiments and implementation described and shown, but encompasses any variant.

Claims (13)

Method for reading the cross section of the bezel (10) from a circle or frame (11) of spectacle frame at at least one point thereof, characterized in that, having a movable probe (12) whose position can be identified in a given coordinate system, this probe (12) is brought to the right of the bezel (10), by successively aiming at the head (15) of this probe (12) at least two points (P1 , P2, P'1, P'2) of at least one of the sides (13, 13 ') of this bezel (10) different from each other, to deduce the coordinates of these points (P1 , P2, P'1, P'2). Method according to claim 1, characterized in that, the probe (12) which is available having, for the aiming of the bezel (10), an intangible head (15), one acts alone on one of the sides (13, 13 ') of the bezel (10), without interference with the other of these sides (13, 13'). Method according to claim 2, characterized in that the other side of the flanks (13, 13 ') of the bezel (10) is then also operated. Method according to any one of Claims 1 to 3, in which the section of the bezel is in the form of a dihedron, characterized in that two points (P1, P2, P'1, P'2) of at least one of the sides (13, 13 ') of the bezel (10) different from each other, and the coordinates of these points (P1, P2) are deduced , P'1, P'2) the slope of this flank (13, 13 '). Method according to any one of Claims 2 to 4, in which the probe (12) is a contact probe, characterized in that, the probe (12) being in contact by its head (15) with one of the flanks (13, 13 ') of the bezel (10), it is made to slide along this side (13, 13'). Method according to Claim 1, in which the probe (12) is a contact probe, characterized in that, the probe (12) available having, for contact with the bezel (10), a head (15A, 15B ) interchangeable, we intervene simultaneously on the two sides (13, 13 ') of the bezel (10) with a first head (15A) of this probe (12), and we proceed then likewise with a second head (15B) of this feeler (12) of a caliber different from that of the first head (15A). Probe for implementing a method according to claim 6, characterized in that it comprises, associated with the same rod (14), at least two heads (15A, 15B) of different sizes. Probe according to claim 7, characterized in that the two heads (15A, 15B) are each respectively arranged permanently at the two ends of a crosspiece (16) carried by the rod (14). Probe according to claim 7, characterized in that each of the heads (15A, 15B) is carried by an individual endpiece (18A, 18B) by which it is adapted to be removably attached to the rod (14). Probe according to claim 9, characterized in that the end piece (18A, 18B) is of the same type for the two heads (15A, 15B), and it is a end piece (18A, 18B) capable of cooperating in fitting with a tip (19) provided in a complementary manner for this purpose on the rod (14). Probe according to any one of Claims 7 to 10, characterized in that two heads (15A, 15B) are spherical heads of different radii (RA, RB). Application of the method according to any one of claims 1 to 6, according to which the cross section (13, 13 '; 110) of the bezel (10) and the cross section (30, 130) of the grinding wheel intended to overflow the glass that must receive said bezel (10) are brought together until simulating the mounting of the glass in the bezel (10), and we deduce the instructions to give to the grinding wheel for the overflowing of the glass. Application according to claim 12, characterized in that the said instructions are developed from the offset (40, 140) noted between the image Co of the circumferential contour of the bottom (21, 121) of the bezel (10) and the image of the top (31, 131) of the bevel of the glass represented by the bottom of the groove of the grinding wheel.

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