EP0483008B1 - Lenses alignment device with rotating table - Google Patents

Description

The present invention relates to a gliding device according to the preamble of claim 1 (see eg EP-A-323,787). By slipping is generally understood the fitting, on a lens of glasses to work, and for example to overflow, of a block, said here by simple convenience gripping block, which, adapted to not adhere to such spectacle lens that temporarily, for example by means of a suction cup, is intended to allow it to be put in place, and locked in position, on a machine suitable for the work to be performed.

The invention relates more precisely to the case where this installation is carried out using a device, commonly called a gliding device, comprising a gliding member, which is adapted to receive, in a removable manner, the gripping block to be posed , and which is carried by a carriage mounted movable along a path during which, by the gripping block which it carries, it interferes with the spectacle lens to be fitted and therefore comes into abutment, by this gripping block, against the piece that constitutes this spectacle lens.

One of the problems to be solved in gliding devices of this type is due to the need to control the travel of the carriage in a sufficiently precise and reliable manner so that, after contact with the glass of glasses to be fitted , the stress on which this spectacle lens is then subjected is not such as to inadvertently cause it to break.

The present invention generally relates to a provision making it possible to satisfy this requirement in a particularly simple and economical manner.

This object is achieved by a type of gloving device comprising a plate suitable for receiving the spectacle lens to be fitted and characterized in that this plate is pivotally mounted on a fixed base, and in that, between it and this fixed base , involved, on the one hand, calibrated elastic means, and, on the other hand, a displacement detector.

Preferably, these calibrated elastic means use at least one sine washer.

As we know, a sine washer is a tiled washer.

As is known, also, a sine washer responds perfectly calibrated elastic characteristics well determined.

Commonly available commercially, it is also relatively inexpensive to purchase.

Anyway, the combination made, according to the invention, of such a sine washer, at least, and a displacement detector, advantageously makes it possible to determine with great precision the instant when, during the fitting a gripping block, the force applied to the spectacle lens concerned reaches a given value, and to intervene accordingly on the drive means of the trolley at the origin of this force.

Thus, it is very simply and economically supplemented with a pressure sensor which would be much more expensive and delicate.

• la figure 1 est, avec des arrachements locaux, une vue partielle en élévation d'un dispositif de glantage suivant l'invention ;
• la figure 2 reprend, à échelle supérieure, le détail de la figure 1 repéré par un encart II sur cette figure 1 ;
• la figure 3 est une vue partielle en coupe transversale, suivant la ligne III-III de la figure 1 ;
• la figure 4 est une autre vue partielle en coupe transversale, suivant la ligne IV-IV de la figure 1 ;
• la figure 5 est une vue partielle en élévation-coupe, suivant la flèche V de la figure 3 ;
• la figure 6 est, à échelle différente, une vue en perspective d'une des rondelles sinus mises en oeuvre dans le dispositif de glantage suivant l'invention ;
• la figure 7 est une vue en coupe longitudinale de cette rondelle sinus, suivant la ligne VII-VII de la figure 6 ;
• la figure 8 en est une vue en coupe transversale, suivant la ligne VIII-VIII de la figure 7 ;
• la figure 9 est une vue partielle en élévation, qui, analogue à celle de la figure 1, concerne une variante de réalisation.

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, with local cutaway, a partial elevational view of a gliding device according to the invention;
• Figure 2 shows, on a larger scale, the detail of Figure 1 identified by an insert II in this Figure 1;
• Figure 3 is a partial cross-sectional view along line III-III of Figure 1;
• Figure 4 is another partial view in cross section along the line IV-IV of Figure 1;
• Figure 5 is a partial view in elevation-section along the arrow V of Figure 3;
• Figure 6 is, on a different scale, a perspective view of one of the sine washers used in the gliding device according to the invention;
• Figure 7 is a longitudinal sectional view of this sine washer, along the line VII-VII of Figure 6;
• Figure 8 is a cross-sectional view along the line VIII-VIII of Figure 7;
• Figure 9 is a partial elevational view, which, similar to that of Figure 1, relates to an alternative embodiment.

As illustrated in these figures, and in a manner known per se, the gliding device 10 according to the invention comprises a plate 11, which, forming a centering table, is suitable for receiving the spectacle lens 12 on which must be placed a gripping block (not shown), having for this purpose, regularly distributed around an axis A1, or laying axis, three studs 13.

The other constituents of the gliding device 10 not being concerned with the present invention, they have essentially not been shown in the figures, and they will not be described here.

Only partially appears, in Figure 1, the frame 14 allowing this gliding device 10 to be attached to any support, and, for example, on the frame of a contour reading device.

According to the invention, the plate 11 is pivotally mounted on a fixed base 15, and, between it and the latter, operate, according to methods described in more detail later, on the one hand, calibrated elastic means 16, and, on the other hand, a displacement detector 18.

The base 15, which is only shown schematically, here and there, in the figures, does not fall under the present invention either, and it will therefore not be described in more detail here.

It will suffice to indicate that it belongs, for example, to an optical box.

In any event, it is fixed in position relative to the frame 14, and, from a functional point of view, everything therefore happens as if it belonged directly to it.

In practice, the pivot axis A2 of the plate 11 is orthogonal to the laying axis A1.

In the embodiment shown, it is materialized by two screws 20, with conical end 21, which, in engagement, each respectively, with two ears 22 which is fitted for this purpose the plate 11 on its lower surface, cooperate with two bearings conical 23 provided for this purpose in correspondence on the base 15 and thus form two pins.

As is easy to understand, the corresponding mounting is such as to guarantee a rigorous position of the plate 11 relative to the laying axis A1, with the only degree of freedom that corresponding to its pivoting.

Preferably, and as shown, the calibrated elastic means 16 intervening between the plate 11 and the base 15 comprise at least one sine washer 24.

As is known, a sine washer is a tiled metal washer, that is to say a metal washer generally curved on a cylindrical surface.

Such a sine washer 24 is shown in isolation in FIGS. 6 to 8.

Let D1 be the direction of its generators.

As is known, also, a sine washer 24 has the advantage of resisting elastically in a calibrated manner when it is the object of a crushing stress.

For example, the force required to crush it in half is more than half that required to lay it completely flat.

The margin of maneuver thus left free by such a sine washer 24 is therefore significant.

In practice, in the embodiment shown, two sine washers 24 are used, in a direction D2 parallel to the pivot axis A2 of the plate 11, at a distance from this pivot axis A2.

They both operate on the lower surface of the plate 11.

In practice, they each have their concavity turned towards the base 15, and the direction D1 of their generatrices is oriented perpendicular to the pivot axis A2 of the plate 11.

In other words, the directions D1 of their generatrices are parallel to each other, and they are perpendicular to the direction D2 in which they are aligned.

In practice, each of the sine washers 24 thus implemented is individually disposed in a housing 25 provided hollow for it on the base 15, and, by its central opening 26, it is engaged there on a centering pin 27 projecting from the bottom 28 of this housing 25.

In practice, when, as shown diagrammatically by specific hatching in FIG. 2, the base 15 is made of synthetic material, there is provided, on the bottom 28 of this housing 25, for support of the sinus washer 24, a metal washer 30 .

To avoid, moreover, from interfering with the centering pins 27, the plate 11 has, to the right of each of them, a recess 31, suitable for its engagement at least partially around them.

Preferably, and as shown, to mitigate the consequences of a possible aging of the two sinus washers 24 thus implemented, which are however able to collect without slackening more than one hundred thousand operations, it is provided between the base 15 and the plate 11, auxiliary elastic means 32.

In the embodiment shown, these are two leaf springs 33, which, generally in the form of a widely stretched Z, are carried by the base 15, and on which the plate 11 bears on its lower surface.

From the elastic point of view, the two spring leaves 33 thus implemented only slightly shift upwards the calibration provided by the sinus washers 24.

Anyway, it is provided, finally, to precisely define the rest position of the plate 11, a stop 34, which is carried by the base 15, and against which the elastic means 16, 32 acting between it and the plate 11 permanently urge the latter to bear.

In the embodiment more particularly shown in FIG. 1, the displacement detector 18 also comprises, linked to any one of the elements that constitute the base 15 and the plate 11, a photoelectric cell 35, and, linked to the other, a probe 36.

In practice, in this embodiment, the photoelectric cell 35 is linked to the base 15, for example being carried by the frame 14, as shown, and the probe 36 is linked to the plate 11, by being, for example, and as shown, carried at the end of an arm 37 integral with the latter.

Anyway, this probe 36 is preferably adjustable in position.

For example, it is the end of a screw in screwed engagement with the arm 37 which carries it.

As it is easy to understand, when, under the stress of a laying force acting along the laying axis A1, the plate 11 is the object, by pivoting around its pivot axis A2, of sufficient penetration, duly calibrated by the calibrated elastic means 16 constituted by the sinus washers 24, the probe 36 of the displacement detector 18 causes its photoelectric cell 35 to shut down.

According to arrangements which, not pertaining to the present invention, will not be described here, this results in an intervention on the drive means then ensuring the installation of a gripping block on the spectacle lens 12 placed on the plate. 11.

However, by construction, the force then exerted on it can advantageously be duly controlled.

With regard to the lever arms in play, it suffices to choose the sine washers 24 implemented accordingly.

For example, these sine washers 24 are crushed by half for a force of 8 N while the overcalibration due to leaf springs 33 is only 5N (500 g).

However, it goes without saying that the numerical values thus given by way of illustrative example should in no way be considered as limiting the invention.

In practice, depending on the nature of the spectacle lenses to be fitted, two types of operation can be envisaged.

For example, in the case of fragile glasses which can only absorb a relatively low laying force, the gripping block to be used is a simple self-adhesive pad, which is satisfied with such a relatively low laying force. , but the number of possible successive uses is however relatively small.

On the contrary, if they are more resistant glasses, that is to say glasses which can withstand higher laying forces, the gripping block used is a suction cup which effectively requires for its laying an effort higher, but which can advantageously be reused a number of times also higher.

According to provisions which, not pertaining to the present invention, will not be described here, the operator then has control means allowing him to switch at his discretion from one of these types of operation to another.

In the embodiment more particularly shown in FIG. 9, the displacement detector 18 comprises, linked to any one of the elements that constitute the base 15 and the plate 11, a Hall effect cell 35 ′, and, linked to the other, a 36 'magnet.

In practice, in this embodiment, the Hall effect cell 35 ′ is linked to the base 15, for example by being carried by a printed circuit board 38 duly secured thereto, as shown diagrammatically in FIG. 9, and , jointly, the magnet 36 'is linked to the plate 11, for example being carried as previously by an arm 37 integral with the latter.

The operation is generally of the type of the previous one.

But the Hall effect cell 35 'has the advantage of giving information proportional to the displacement of the plate 11, and therefore a function of its position relative to its rest position.

As a result, all mechanical adjustment is eliminated, an automatic reset occurring systematically at each operating cycle.

Of course, the present invention is not limited to the embodiments described and shown. It is possible, for example, to provide alternative embodiments with regard to the nature of the calibrated elastic means used and, in the case of sine washers, the number and / or the orientation of those -this.

Claims (15)

1. A holding device of the type comprising a plate (11) capable of receiving the spectacle lens (12) on which a gripping unit must be placed, characterised in that said plate (11) is pivotally mounted on a fixed base (15), and in that placed between it and said fixed base (15) are calibrated elastic means (16), on the one hand, and a displacement detection means (18), on the other hand.
2. A holding device according to Claim 1, characterised in that the calibrated elastic means (16) comprise at least one curved round disc (24).
3. A holding device according to Claim 2, characterised in that the concavity of the curved round disc (24) is turned towards the base (15).
4. A holding device according to any one of Claims 2, 3, characterised in that the direction (D1) of the generatrices of the curved round disc (24) is oriented perpendicularly to the pivot axis (A2) of the plate (11).
5. A holding device according to any one of Claims 2 to 4, characterised in that the curved round disc (24) is disposed in a recess (25) which is hollowed out in the base (15), and is engaged there on a centering piece (27) which projects over the base (28) of the recess (25).
6. A holding device according to Claim 5, characterised in that since the base (15) is made of a synthetic material, provided on the bottom (28) of the recess (25) in which the curved round disc (24) is disposed is a round metal disc (30) against which the curved round disc can bear.
7. A holding device according to any one of Claims 2 to 6, characterised in that there are two curved round discs (24) in a direction (D2) which is parallel to the pivot axis (A2) of the plate (11), at a spacing from that pivot axis (A2).
8. A holding device according to any one of Claims 1 to 7, characterised in that provided between the base (15) and the plate (11) are auxiliary elastic means (32).
9. A holding device according to any one of Claims 1 to 8, characterised in that an abutment (34) is provided against which the elastic means (16, 32) coming into play between the base (15) and the plate (11) are permanently urged against this latter.
10. A holding device according to any one of Claims 1 to 9, characterised in that the pivot axis (A2) of the plate (11) is formed by two screws (20) with conical ends (21), which screws cooperate with conical rollers (23).
11. A holding device according to any one of Claims 1 to 10, characterised in that the displacement detection means (18) comprises a photoelectric cell (35) which is connected to any one of the elements forming the base (15) and the plate (11) and a sensor (36) connected to the other.
12. A holding device according to Claim 11, characterised in that the sensor (36) is adjustable in position.
13. A holding device according to any one of Claims 11, 12, characterised in that the photoelectric cell (35) is linked to the base (15) and that the sensor (36) is linked to the plate (11).
14. A holding device according to any one of Claims 1 to 10, characterised in that the displacement detection means (18) comprises a Hall effect cell (35') which is linked to any of the constituent elements of the base (15) and plate (11), and a magnet (36') which is linked to the other.
15. A holding device according to Claim 14, characterised in that the Hall effect cell (35') is linked to the base (15) and the magnet (36') is linked to the plate (11).

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