DE1652221A1 - Multi-part ring holder for lens blanks - Google Patents

Description

5323

Univis, Inc., Fort Lauderdale, Florida, U.S.A. Multi-part ring holder for lens blanks

sssssssssgasaBssssssss-saessss :: = «=:

The invention relates to the production of Aujigen glass lenses, especially on holding these lenses so that they can be used in devices for manufacturing and polishing their surfaces as well as in facilities for edge grinding the lenses can be processed according to a recipe. In detail the invention relates to. lens manufacturing as well on mounts of the type shown in the pending patent applications TJ 12 417 Ib / 6? A, filed February 3, 1966 and U 13 579 Tb / 67a, filed February 22, 1967 are. A bracket is generally understood to mean a rigid version which is temporarily attached to the Surface of a lens for the purpose of holding and adjusting attached to the lens while it is undergoing further operations.

The benefits of performing a single holding processa for the purpose of manufacturing, grinding and polishing prescribed ophthalmic lens surfaces and

10 9 811/0378

for edge grinding and finishing are in the registrations listed above. According to the earlier application, the radially outer parts of the bracket, which usually interfere with the final edge or edge work, intentionally removed. After the later registration, the bracket is cast in two pieces, in such a way, that the outer part can be easily and independently removed from the inner part, before the formation of the final edge contour on the lens blank.

Taking into account the above, there is a need to create a two-part ring holder by means of which produced the prescribed optical surface on the lens blank and polished and in which the outer ring can be easily and independently removed so that the inner ring can be used for the final edging or edging operations can be used.

There is also a need for a method of manufacture To create a two-part ring holder of this design, which also has the advantage of using metallic Alloy with a low melting point makes use, which is extremely useful in holding eyeglass lenses have turned out to be appropriate;

According to an exemplary and preferred embodiment

10 981 y 0378

According to the invention, a two-piece ring retainer is attached to the finished side of a lens blank through the use of modified means of the type described in the above-identified applications. The individual rings preferably are preformed of a suitable resinous _material} and is then in connection with the assignment of the pair of companion rings at the selected Mnsenrohling according to the prescribed alignment an alloy with a low melting point for the purpose of mounting of the rings on the blank in this positional relationship introduced. The outer ring has a congruent ring shape and includes an outer surface which is related to the final optical center of the finished lens and a pair of diametrically opposed slots formed in that surface and arranged to serve as a reference point for the prescribed cylinder axis serve. Under these circumstances, the outer ring can be used to produce the prescribed optical surface on the unmachined side of the lens blank * The inner ring is provided with an inner ring surface that is related to the final mechanical center of the machined lens. In addition, the inner ring is provided with two parallel walls, each of which is parallel to the final horizontal axis of the lens being machined, and in the case of a lens with two focal points, these walls are parallel

1098 11/0378

to the segment line. One between those parallel walls Activated ring groove · cooperates with surfaces of a ring holder of the mounting device to form an articulated connection train between these parts. As a result, a tilting or inclination of the ring is advantageously made possible, while this ring is being adjusted and aligned on the lens blank, prior to the ring mounting process is performed. A cylinder reference axis in the form of two milled seat braids in the side walls of the inner ring is also provided so that the optical surface is finally ground and polished can. The inner ring can then be used to form the final edge or edge contour on the lens.

The invention will now also be described in detail with reference to the accompanying drawings, all of which are taken from the description and the details shown in the illustrations or Features can contribute to the solution of the problem within the meaning of the invention and with the will to be patented in the application were recorded. Show it:

Fig. 1 is a plan view of a lens with two focal points, on one side surface of which a two-part ring holder attached in accordance with the teachings of the invention;

10981 1/0378

Fig. 2 is an enlarged partial cross-sectional view of this Lens blank and holder taken along line 2-2 of FIG. 1;

Fig. 3 is a view of the parts from below;

Fig. 4 is a further plan view showing the positional relationship of the represents inner ring to the double focus segment, wherein the outer ring is indicated by dash-dotted lines and the intermediate alloy binding material is removed;

5 is a perspective view of the Lens blank and inner and outer rings;

6 is a partial sectional view of the apparatus for forming the double ring holder on the lens blank, with the inner ring in dashed lines before pouring the alloy binding material in a raised position and also shown in a lower position indicated by full lines following the start of the pouring process is; ·

Fig. 7 is a sectional view taken along the line 7-7 of Figure 6, wherein the inclination of the holder is indicated in dash-dotted lines.

1098 1170378

1662221 6

Figure 8 is a top plan view of the lens being held or fixed following the preceding edge processing operation for deforming the lens blank around its optical center using the inner ring;

Fig. 9 is a side view, partly in section, showing the Raw grinding or making the prescribed optical Surface on the non-machined side of the lens blank and the subsequent finer grinding and polishing processes illustrated and

Figure 10 is another top plan view with the outer ring and intermediate alloy binding material removed whereupon the final edge contour is worked into the lens blank.

In the drawings is a supported or fixed lens assembly 10, which includes a typical semi-finished lens blank 12 and a two-piece ring retainer 14, which is attached to the blank. The lens blank is shown in the general condition in which the optical Workshop obtains from the supplier. As previously discussed, lens blank 12 can be one of a number of take on other shapes, and the finished lens can similarly come from a wide range of in Industry known lenses can be selected. E.g. can a Blank 12 can be assumed which has two focal points and

10 9 811/0378

16Ü2221

a main section with a certain refractive index as well as a double focus segment of different refractive index. Also, the front or outer Side of the blank, which is usually on the outside in the finished glasses, already on a predetermined, usually spherical contour, machined. The back receives the prescribed visual appearance through further processing Surface, in accordance with the necessary optical corrections for the individual eyes of the wearer of the glasses.

Regarding the two-part ring holder 14, it should be noted that an outer ring 16 and an inner ring 18 are secured to the finished side of the lens blank 12 " by means of a suitable connecting material, which may preferably consist of an alloy 20 having a low melting point. A suitable one The connecting alloy, which has the required adhesion to the lens surface and the rings 16 and 18, consists of an antimony-lead compound (or t ^ l.), Which has a melting point of about 70 ° C (158 ° 1) State potted in a manner to be described and cures relatively quickly, e.g. in about 30 seconds A wide range of materials can be selected for rings 16 and 18. The rings are preferably cast from a suitable resinous material

109811/0378 - 7 -

contain polystyrene, high-temperature polypropylene, geleon (a thermoplastic material consisting essentially of ethylene gelulose and plasticizers) and polyallomer (a crystalline thermoplastic polymer composed of two or more different monomers of saturated hydrocarbons. fabric is made),

The rings 16 and 18 of the bracket 14 form the desired and selected optical and geometric reference points of the prescribed finished lens, in this context contains the outer, substantially circular Ring 16 has an outer surface 22 that acts as an optical centering serves, the axial center line of the. optical centering with the final optical center of the finished Lens collapses, pre-formed seat braid 24 and 26, which are diametrically opposed to each other, become in correspondence prior to the insertion of the connecting material 20 aligned with the prescribed cylinder axis of the lens. Under these circumstances, the slots 24 form and 26 cylinder axis reference points which are used to generate the optical surface on the non-machined side of the lens blank 12 can be used. One of the edges of the ring 16 is provided with radially inwardly extending projections 28 which hold the ring 16 at a distance from the lens blank 12 and at the same time connect the ring 16 to the connecting material 20 and anchor. Shoulders 30 act for this purpose

1098 11/0378

- O -

on each fortsat25 28 as a mechanical latch to maintain the connecting force between the connecting material 20 and the material of the ring 16 to supplement.

In connection with the inner ring 18 it is noted that this part has an outer, substantially conical surface 32 and an inner, inverted conical surface 34. the inner surface 34 serves as a mechanical centering. Inside the cavity delimited by the inner conical wall 34 there are two substantially parallel walls 36 and 38, the outer sides 40 and 42, respectively, in a similar manner run parallel and are arranged fairly parallel to the horizontal axis of the finished lens. In the event of a lens with two focal points is horizontal Reference axis essentially parallel to the upper segment line of the double focus segment. The inner side of the walls 36 and 38 merges into an arcuate groove 44 which serves to an articulated connection between the inner ring 18 and a To create holder for this, which for the purpose of the correct setting and orientation of the inner ring 18 according to the specification for the lens blank 12 for use comes. The way in which this is accomplished will still described. At least one, and in the case of the exemplary embodiment, two diametrically opposed slots 46 and 4 & is, respectively, are in the outer edge of the inner ring 18 and serve as cylinder axis reference points for the inner ring «

_ ₉ _ 109811/0378

It is now on Pig. 6 referred to. This shows the arrangement for receiving and holding the lens blank 12 and the rings 16 and 18 in the desired and prescribed Relationship and for the mutual connection of these parts by means of the connecting material 20. The arrangement shown forms part of the mounting device, which is in the above-mentioned pending patent applications. The technician thus first brings the blank 12 between a lower support 50 and an outer *, rotatable one. Form 52. Then the blank is clamped between these parts after it is precisely aligned and an adjustment on the cylinder reference axis is achieved in that the shape 52 a suitable distance relative to the horizontal Axis is rotated, which in the case of a lens with two focal points runs parallel to the SegmetliTi * - /. The cylinder axis intersects the port sets 54 and 56 which are conveniently received by the outer slots 24 and 26 of the outer ring 16 will. In this context, it should be noted that the outer ring in the outer molded body 52 following the Clamping process or at a suitable time before this can be used. It is noted that the extensions 28 are completely embedded in the connecting material 20 for all cases and purposes. In this way, the annular outer surface 58 of the connecting material 20 pulled apart so that a vacuum seal is reliably formed for clamping purposes when the prescribed one optical surface on the non-machined side of the blank is roughly ground by the processing device. ·

109811/0378

- 10 8AD ORIGINAL

■ T6S2221

As shown by the dashed line in lig .. 6, will initially the inner ring 18 at the beginning of the casting of the connecting material 20 held out of the valve-controlled pouring opening 60 in a raised position. The inner ring is held by the holder 62, and the spring clip η and 66 come directly into engagement with parallel wall surfaces 40 and 42, respectively. When the inner ring ao is held, the parallel surfaces 40 and 42 are parallel to the horizontal axis of the machined lens blank arranged

Immediately following the casting of the connecting material 20, the holder 62 and consequently the one carried inner ring 18 lowered into a position on the lens blank 12. The connecting material 20a is in the inner ring cavity 68, with the air trapped in the cavity being forced out through the vents 70 and 72 will. The desired horizontal orientation of the inner ring 18 is following the downward movement of the inner Ring in contact with the Lins.enrohling 12 through the articulated connection obtained by the arcuate groove 44 · and the two spaced apart, downwardly projecting spherical bodies 74 and 76 of the holder 62 is formed. This articulation allows the inner Ring 18 relative to the holder 62 on the lens blank 12 can tilt about an axis that is relatively close to the machined Surface of the blank lies. It is also

109811/0378

16Ü2221

notices that an optimal and enlarged surface contact between the connection material 20a and the surfaces of the inner ring 18 that delimit the cavity 68. In this context, a beveled edge 78 is provided on the lower part of the ring 18 in such a way that if possible, only a hairline contact between the inner one Ring 18 and the machined side of the blank 12 is present, and for all purposes and cases the inner ring 18 is from this by means of the interposed connecting material 20a kept at a distance. After completion of the casting cycle and the setting of the connecting material 20 and 20a the holder 62 is withdrawn and the lens and block assembly 10 is finally removed from the holder

Since the inner ring 18 for the purpose of Pertigschieifens and Polishing of the optical surface is used, which is attached to the non-machined side of the blank 12 is produced, a cylinder reference axis is introduced before this ring is in the holder is inserted and adjusted on the holder 62. This is achieved simply by having the cylinder axis reference slots 46 and 48 are milled out on the outer edge of the inner ring 18. As will be understood by those skilled in the art, 1st the definition of the cylinder reference axis at this stage of the Holding process a relatively simple matter and can be achieved by a device that takes advantage of the existing horizontal reference axis on the inner ring 18 makes use of »

- 12 - '1098 1 17 0 37 8

For machining the lens blank 12, the lens blank is then placed thereon and the bracket assembly 10 is mounted in an edging or edging or contouring device that has a Uinfangkonturrana 80 forms on the blank 12, one of which suitable embodiment is shown in FIG. The jig this device can be engaged with the conical inner surface 34 of the inner ring 18 which is the mechanical Centering allows, and the parallel horizontal alignment reference surfaces 40 and 42 of this ring to be brought. As a result, the desired edge or marginal contour 80 is formed on the blank 12, specifically in relation to it on both the mechanical center point and the horizontal axis of the finished lens, and in this way the blank is formed into a balanced condition around the final mechanical center point, and the The size of the semi-machined blank is considerably reduced.

Following this contour machining, the arrangement in a conventional toric or spherical surface generating machine for rough grinding the prescribed optical surface attached to the non-machined side of the blank 12. During this process, the optical centering surface 22 together with the cylinder axis wedge strands 24 and 26 in this for attaching and adjusting the assembly 10 in the jig of FIG

109811/0378 - 13 -

16 b 2 2 21 1H

Machine or generator used. As mentioned above, the substantially uninterrupted circular Surface 58 is provided, conveniently in engagement with vacuum sealing devices of a vacuum chuck of the generator to come. In these circumstances, the prescribed optical or toric surface on the lens blank manufactured and according to the special regulation properly oriented on this.

Once the toroidal surface is made on the blank 12, it can be finely ground and polished using conventional surface processing machines. Exemplary apparatus of this type is described in the previously filed patent application mentioned above. The jaws of this surface processing machine can engage with the mechanical centering surface 34 and are brought to the cylinder axis reference slots 46 and 48 * While the invention the fine grinding and polishing after the removal of the outer ring 16 and the interposed connecting material 20, and even after the final edge or edging suggests, however, it is still also preferable to carry out the finish machining of the optical surface generated prior to the removal of the outer ring 16 and the compound material 20th

At this stage of machining, the outer ring 16

109811/0378

- 14 -

16S2221

and the interposed connecting material 20 is removed from the lens blank 12, and the inner ring 18 is left thereon and held to the blank by means of the interposed layer of adhesive material 20a. The removal of the outer ring 16 and the connecting material can be achieved simply by the inner ring 18 firmly clamped to the lens blank and then the outer ring 16 and the "neighboring metal with the low melting point are knocked loose from the lens, namely by a suitably executed or steered sharp ^v or hard blow Cleanly remove ring 16 and connecting material 20 from lens blank 12 independently of inner ring 18.

To get the one in Pig. 10 to generate the object shown, is the final edge contour worked out on the blank 12 «In In this context, it should be noted that the arrangement is used in a conventional device for Pertigrand processing whose jigs are in engagement with the (|

mechanical centering surface 34 of the inner ring 18 and the horizontal alignment reference surfaces 40 and 42 can be brought. The final edge contour is therefore on the machined lens around the mechanical center around while it is related to the horizontal orientation. The inner ring 18 can now together with the intermediate layer of the connecting material 20a can be easily removed by the ring with a bite

10 9 8 11/0378

- 15 -

BADORlGINAt

• 16-b2221 U

pliers are squeezed, which destroys the connecting material and the inner ring 18 and tie layer 20a are released from the finished lens.

Numerous advantages are reliably achieved here, among other things. For example, mechanical centering and optical centering both provided on the single bracket, with the outer detachable ring on the optical center of the machined Lens is aligned and has the prescribed cylinder reference axis. The inner ring is on the other hand aligned with the mechanical center of the machined lens and also with reference points for the horizontal alignment and the prescribed cylinder axis of the machined Lens provided. In addition to the above advantages, there is a Another important advantage is that the assembly 10 prior to grinding and polishing an edge or edge processing using the mechanical centering and the horizontal reference axis that appear on inner ring are provided. As a result, the holder .14 can be essentially in the geometric center of the lens blank set with the pre-machined edge. The area or Zone of the lens blank, which extends beyond the edge of the holder 14 on all its sides, is then in the essentially the same. This allows uniform grinding and polishing pressures on all sections of the underside or Grinding surface of the lens blank are exerted, whereby

_ ₁₆ _ 10981 1/0378 BAD ORIGINAL

I6S2221

Again, it is prevented that the optical center is located moved away from its original and prescribed location. The elimination of the tendency of the optical center, away from its original prescribed position relocate is of the utmost importance

10 9811/0378

Claims (1)

it Pat e η t <a n s ρ r ü c h e 1. Multipart Ringhaiterung ^r füxrLinsenrohlinge with a centrally arranged ring for attachment to one side φ of a lens blank S: for the purpose; Bracket; of the blank in one Device for processing the edge of the lens blank, g e k en η ζ ei c h- net d u r c h an outer one Ring (14) extending from the central ring (18) to the outside in Spaced and on the same side of the blank (12) is tackable to the blank during a previous one Step in the manufacture of the lens, wherein the outer ring independent of the central ring from the blank is removable. 2. Lens holder according to claim 1, since d u r c h g e k en η ze i c h η et that the rings (14, 18) from a molded organic resinous material. 3 .. lens holder according to claim 1 or 2, since you r c h g e k e η η ζ e i c h η e t that the rings (14, 18) through, a metallic alloy with a low melting point at that Lens blank (12) are attached. 109811/037 8 - 18 - 16b2221 13 4. Lens holder according to one or more of the preceding Claims, characterized thereby ζ e i c h η e t, that the outer ring (14) is quite circular in section and with a number of spaced apart coaxial port sets (28) is provided from one side of the ring protrude, and that the free end (30) of each Port set (28) in contact with one side of the lens blank (12) can be brought. 5. Lens holder according to claim 4 _S, characterized in that each port set (28) is provided with an inwardly projecting shoulder (30) next to the free end, that a connecting means (20) is provided and in contact with the outer ring (14) stands to attach the outer ring to the lens blank (12) and that the connecting means (20) and the shoulders (30) form a mechanical lock which connects the outer ring (14) to the lens blank. 6. Lens holder according to claim 4 or 5 *, characterized in that each port set (28) has an outer side surface and the outer ring (14) has an outer circumferential surface extending in the circumferential direction (22) and arranged further radially outward than the outer surface of the extensions is. . '"* ^v 10 9 811/037 8 19 - BATH ORIGINAL 7. Lens holder according to one or more of the preceding claims, characterized in that the outer ring (14) has radially inner and outer surfaces, that the outer surface (22) represents an optical centering surface which corresponds to the final optical center of the finished lens aligned and the outer surface, de with the jig of a G _e cooperating guide devices (24, 26) nerators which forms the prescribed optical surface on the other side of the lens blank, said guide means (24, 26) to the prescribed cylinder axis of the Lens are related. 8. Lens holder close to one or more of the preceding Claims, characterized in that η ζ e i c h η e t that the inner ring (18) has an outer end spaced apart by one side of the lens blank (12) is arranged, and an inner end (78) disposed near one side of the lens blank that the "inner End (78) of the inner ring with an enlarged cavity (68) for the formation of binding surfaces for a binding agent (20a) is provided which attaches the inner ring (18) to one side of the lens blank, and that the inner End (7ü) of the inner ring is beveled and forms a cutting edge ", such that when the inner ring is attached on one side of the lens blank a hairline is achieved by the connecting means. _ ₂₀ "109 8 1 1/0378 BATH ibb222T if 9 · Lens holder according to claim 8, - dad u r c h characterized in that at least one vent (70, 72) is provided in the inner Hing (18) so that the air can escape from the cavity (68) when the Connecting means (20a) is introduced into this, 10. lens holder according to one or more of the preceding Claims, thereby ge k e η η ζ e i. c h ~ * net that the inner ring is provided with the mechanical centering surface (34) with the final mechanical Center of the machined lens is aligned and that it has a horizontal axis reference surface (40, 42) with the horizontal axis the lens and a cylinder axis reference point (46, 48) which is related to the cylinder axis of the lens. 11. Lens holder according to claim 10, characterized characterized in that the inner ring (18) has a | radially outer (32) and an inner (34) surface, the inner surface (34) forming the mechanical centering surface and that the inner ring (18) is provided with two parallel walls (40, 42) which extend across extend the opening delimited by the inner surface (34) "and that a! Tut (44) is arranged between the parallel walls, the groove and the walls forming the reference point for the horizontal axis and the inner ring ( 18) is provided with at least one milled slot (46, 48) in its outer edge , which forms the reference point for the cylinder axis. 10 9811/0 378 BAD ORtGtNAU «. Ibb2221 12. Lens holder- after. Claim: 1, characterized in that characterized in that the holder has a mechanical centering surface associated with the final mechanical center of the machined lens is aligned, and an optical centering «flat that coincides with the final optical center of the "machined lens is aligned, and that one ring is movable independently of the other ring and .the other ring has reference devices, those on the horizontal, alignment of the machined lens are related, with the surfaces designed and arranged are that the lens blank is accurate and machinable is held, while it is processed into a finished lens is by adding the prescribed optical surface to the not machined side of the lens blank with respect to the optical Centering surface formed and following the Removal of the other ring the edge contour of the machined Lens with reference to the mechanical centering surface and horizontal alignment surface formed on the bracket will. 13. Method of holding a semi-machined lens blank, corresponding to a recipe for an eye-glass— " Lens is to be processed, wherein a lens holder: used according to one or more of the preceding claims is marked you rc h. Support of the semi-machined lens blank in a predetermined ₂₂ 109811/0378 1662221 Position, attachment of an outer circular ring and a central ring that radially inwards from the outer entrance is spaced, on the machined surface of the semi-machined lens blank, the rings being so constructed and arranged be that a mechanical centering surface with the final mechanical center of the machined lens is aligned, an optical centering surface that aligns with the final optical Center of the machined lens is aligned, a horizontal alignment surface, de on the horizontal alignment of the machined Lens is related, and a cylinder reference axis is formed for the final cylinder axis of the machined lens, and wherein the surfaces are further constructed and arranged so that the lens blank is accurate and machinable is held while being processed into a finished lens is by placing the prescribed optical surface on the unmachined side of the lens blank with reference to d.e optical Centering surface and cylinder tension axis and the edge contour of the machined lens with respect to the mechanical centering and horizontal alignment points are formed. 14. The method according to claim 13, characterized in that that the rings are first placed on the supported, semi-machined lens blank and then be fixed by pouring the molten material between these parts selected from a group which includes metallic alloys with a low melting point, __ ₂₃ ^ 109811/0378 BAD ORIGINAL 16S22Z1 15. The method according to claim 13 or 14 »thereby characterized in that the inner ring is initially set in alignment with the lens blank and then is shifted after the casting of the connecting material in contact with this. .16. Method according to one of Claims 13 to 15, characterized in that the outer ring with an optical centering that coincides with the final optical center of the machined lens is aligned, and a cylinder reference axis is provided with the. Cylinder axis the finished lens is aligned, and that the inner Ring with a mechanical centering surface that aligns with the final mechanical center of the machined lens aligns, a horizontal alignment surface that points to the final horizontal alignment of the machined lens -λ ij '- ■ --- and is provided with a cylinder reference axis that is aligned with the cylinder axis of the machined lens. 17. The method according to claim 16, d a d u r "c h characterized in that the cylinder reference axis on inner ring by milling out slots on the inner ring is formed prior to attachment of the same to the lens blank. 1098 11/03 78 BAD OFHGINAL. lbbZ221 18. The method according to any one of claims 13 Ms 17, thereby g e k e η η ζe i c h η e t that the prescribed optical surface on the unprocessed side of the Lens blank is formed, wherein by applying the outer circular ring reference to the optical centering that is related to the final optical center and to the cylinder axis reference surface which is related to the prescribed cylinder axis is related, it is taken that the outer annulus is removed from the lens blank and that the final Edge contour of the machined lens with reference to the mechanical center and the required horizontal alignment of the lens Application of the central ring is formed. 19. The method according to any one of claims 13 to 18, characterized in that the held Lens blank before grinding and polishing using mechanical centering and horizontal Reference axis is preprocessed on the edge, whereby the bracket essentially on the geometric center of the lens blank is set with the preprocessed margin. 20. The method according to any one of claims 13 to 19 _f, characterized in that an articulated connection is formed by surfaces of the inner ring and a holder of the Haiterungseinrichtung for this, thereby inclining the inner ring in all directions on the lens blank prior to the attachment of the inner To enable the ring on the Linaenrohling. ° ^{9 8 1} 1/0378