EP1243381B1 - Arrangement for blocking and clamping optical lenses requiring edge-machining, in particular spectacle lenses - Google Patents

Abstract

The appliance consists of two rotary holder-shafts (10,12), and a block-piece (14) detachably positioned on one side of the optical lens. an adapter (18) for the block-piece is rigidly joined to one of the holder shafts. A sub-assembly clamp (20) has a fixture section joined to a clamping section on one side (26) of the lens. On the opposite side, the sub-assembly has a spherical-headed protuberance contained in a container with parallel grooves. The clamping section swivels on two tilt-axes.

Description

The invention relates to an arrangement for blocking and clamping of optical lenses to be processed at the edge, in particular spectacle lenses, according to the preamble of patent claim 1.

When referring to "eyeglass lenses" below are optical lenses for spectacles made of common materials such as polycarbonate, mineral glass, CR 39, HI index, etc., and any shape of the peripheral edge of the lens or the lens blank to understand that before editing their edge can already be processed on one or both optically effective surface (s) but need not.

In the field of spectacle lens edge processing, the aim of which is to finish the edge of a spectacle lens so that the spectacle lens can be inserted into a spectacle frame, various arrangements or systems are known which serve to block the spectacle lens for edging and between to clamp the rotatable and in the axial direction relative to each other adjustable holding shafts of a spectacle lens edge processing machine.

• Ein Blockstück, das lösbar an einer Seite des Brillenglases angebracht werden kann (siehe z.B. EP-A-0 235 543 : Fig. 4 und 5; EP-A-0 839 603 : Fig. 1 und 2);
• ein Adapter für das Blockstück, der mit einer der Haltewellen der Brillenglasrandbearbeitungsmaschine starr verbunden werden kann und zur drehwinkelorientierten Drehmitnahme des Blockstücks ausgebildet ist (siehe z.B. EP-A-0 235 543 : Fig. 1 bis 3; EP-A-0 839 603 : Fig. 5); und
• eine Spannbaugruppe, die einen Befestigungsabschnitt hat, der mit der anderen Haltewelle der Brillenglasrandbearbeitungsmaschine starr verbunden werden kann, sowie einen mit dem Befestigungsabschnitt verbundenen Spannabschnitt aufweist, der zum kraftschlüssigen Angriff an die andere Seite des Brillenglases ausgebildet ist (siehe z.B. EP-A-0 995 546 ).

These systems consistently have at least the following components:

• A block piece that can be detachably attached to one side of the lens (see, eg EP-A-0 235 543 : Fig. 4 and 5 ; EP-A-0 839 603 : Fig. 1 and 2 );
• an adapter for the block piece, which can be rigidly connected to one of the support shafts of the spectacle lens edge processing machine and for rotational angle-oriented rotational drive of Block piece is formed (see, eg EP-A-0 235 543 : Fig. 1 to 3 ; EP-A-0 839 603 : Fig. 5 ); and
• a tensioning assembly having a fixing portion which can be rigidly connected to the other support shaft of the spectacle lens edge processing machine, and having a clamping portion connected to the attachment portion, which is designed for non-positive engagement with the other side of the spectacle lens (see, eg EP-A-0 995 546 ).

With regard to further known embodiments of the block piece and the block-piece adapter, reference should in this context be made to the brochure "WECO Block-up System D 704. Wernicke & Co. GmbH, Dusseldorf, 3/1990" and the DE-A-198 31 305 directed. In the first-mentioned prior art, the block-piece adapter or the clamping bush has only an eccentrically arranged centering pin as the positioning element. Here there is a risk of tilting of the block piece, if this is to be brought into engagement with the clamping bush, so that the mutual rotational drive elements, ie the teeth can come to rest before a rotation angle orientation of block piece and clamping bush. According to the second-mentioned prior art, a depressed bore is arranged in a drive slot of the block, into which a corresponding pin engages a receiving head provided on a spectacle lens holding shaft in order to be able to apply the raw glass to the block in a precise position on the receiving head. Since the desaxierte bore is arranged as a positioning element in the driver slot, here come the rotational drive elements in front of the positioning elements into engagement.

For fastening the block piece to the spectacle lens, fastening foils, known as adhesive pads, have already become known in the prior art, which are provided on both sides with adhesive (see, for example, US Pat DE-U-92 00 513 ). A problem here is that the fastening film after completion of processing Of the lens and removal of the block piece from the lens often remains on the optical surface and thus must be removed from there, with the risk that scratches on the optical surface arise or any coating, such as an anti-reflective layer is damaged ,

With regard to a further known embodiment of the clamping assembly is finally on the DE-A-25 06 866 referenced, which discloses a lens holder with a half-wave, which carries at its end a ball head. With the free, the half-wave surface facing away from the ball head acts a dome-shaped recess in a disc-shaped investment piece together such that the ball head and the recess form a ball joint through which the disk-shaped investment piece can take any required inclination relative to the axis of the half-wave. The transmission of the torque between the half-shaft and the abutment piece takes place via a transverse pin provided on the ball head, which engages in a groove present on the abutment piece, wherein the ends of the transverse pin are always spaced from the radial ends of the groove. In this prior art, the disk-shaped pad is held by a screw on the ball head, which extends through an opening in the contact piece and is screwed into the ball head. On the side facing away from the ball head side of the investment piece, the screw extends through a transversely displaceable on the investment piece, immediately adjacent to the lens glass and engages behind this disc with her head. In this prior art, the tilt of the pad relative to the ball head is severely hampered by the friction between the disc and the pad. In addition, this known ball joint is structurally associated in both the axial direction and in the radial direction in an undesirable manner play.

The invention is based on the preamble of claim 1 forming DE-A-198 31 305 The object of the invention is to provide an arrangement which is easier to handle than the previously known solutions for blocking and clamping optical lenses, in particular spectacle lenses, which is also optimized in terms of a play-free rotational drive of the optical lens.

This object is achieved by the features specified in claim 1. Advantageous or expedient developments of the invention are subject matter of the claims 2 to 23.

According to the invention, the arrangement for blocking optical lenses comprises a block piece and a block piece adapter, which is formed in a special way, as shown in claim 1, on the one hand for the positive rotational driving of the block piece by the block piece adapter and on the other hand for the rotationally correct positioning of block piece and block piece adapter. For this purpose, both Block piece and Blockstückadapter on the one hand rotary driving elements and on the other hand positioning. The positioning elements are formed by a plurality of projections on one of the two block piece and block piece adapter parts and by the projections complementary recesses on the other of the two parts. The arrangement is made such that the end faces of the projections lie in an imaginary common plane perpendicular to the axis of rotation, while the recesses emanate from a plane parallel to this plane flat surface. In addition, the axial distance between the rotary driving elements and the positioning elements on the block piece is different from the axial distance between these elements on the block piece adapter. Due to this embodiment of the invention come on approach of the block piece to the thus not yet rotationally correct arranged Blockstückadapter first, the end faces of the projections to rest on the flat, the recesses having surface without the rotary driving elements engage with each other. Then, the correct rotational angle orientation is brought about by rotating the block piece relative to the block piece adapter, wherein the end surfaces of the projections slide on said planar surface, the projections finally, axial alignment between the block piece and block piece adapter, enter the recesses for fixing the relative rotational angular position, until upon further approach of the block piece to the block piece adapter, the rotary drive elements engage each other.

As is apparent from claim 2, three projections and correspondingly three recesses may be provided, wherein the projections or their end faces and the recesses or their inlet openings in each case form the vertices of matching triangles. Due to this configuration, it comes to a secure jam-free support of the block piece on the Blockstückadapter, without partially already rotary driving elements get into an undesirable procedure. In doing so, the protrusions hold the block piece to the block piece adapter at a distance until the correct relative angular position is reached. Then then get all rotary driving elements circumferentially engaged.

According to claim 3 is provided to facilitate the entry of the projections in the recesses, that the projections starting from their end faces and / or the recesses starting from the flat surface at their inlet openings bevels.

Preferably, and as stated in claim 4, the Vorspünge on Blockstückadapter and the recesses are on the block piece.

The block piece according to claim 5 preferably has a hub portion having the positioning elements and an outer ring portion elastically connected thereto, which carries the rotary driving elements of the block piece. The elastic connection to the ring portion and the hub portion allows a facilitated and better adaptation of the block piece to bulges of the lens to be processed.

The aforementioned elastic connection between the hub portion and the ring portion can od in accordance with claim 6 by a plurality of uniformly distributed on the circumference. The like. Are brought about. When injection molding of the block piece of a suitable thermoplastic plastic hub portion, webs and ring portion may be integrally formed. Instead of individual webs can be provided between the hub portion and ring portion and a circumferentially continuous annular thin-walled connection, which similar flexible deformation between ring portion and hub portion for adaptation to a lens curvature allows.

The rotary driving elements on the block piece and the block piece adapter are designed according to claim 7 as complementary ring gears or ring gear sections. These ring gears have due to their radial tooth alignment possibly in conjunction with complementary conical design of the ring gears a block piece and block piece adapter centering effect.

Advantageously, by the specified in claim 8 training the clamping assembly allows a very accurate and backlash-free torque transmission at a very smooth angle compensation. The mounted in its receiving portion ball head with its two projections allowed kardangelenkähnlich superimposed movements about two tilt axes with virtually no play rotational drive through the associated support shaft due to the engagement between the projections and the grooves of the receiving portion. Since the groove bottom of each of the grooves in cross-section to the end portion of the associated projection complementary or form- and dimension corresponding training, as shown in the groove cross-section and projection longitudinal section results in a positive engagement between the projections and the grooves, which for a play-free rotary motion transmission between the ball head and receiving portion is advantageous. The thus achieved backlash with minimal wear and at the same time easy tilting is an essential prerequisite for high-precision edge processing of spectacle lenses in industrial machines.

A respect to the first tilt axis exactly aligned alignment of the two projections of the ball head can be achieved by the measures of claim 9, which provide the introduction of a projecting on both sides above the ball head protruding pin in a guided with its central axis through the center of the ball through hole which encloses the pin without play.

By the specified in claim 10 cylindrical surface areas on both projections in cooperation with the surface areas associated planar guide surfaces of the grooves according to claim 11 ensures that during pivoting movements about the second tilt axis, the substantially rotational play free guidance of the projections is maintained in the grooves.

With regard to a slight tilting mobility of the clamping portion, it is furthermore advantageous if the end regions of the projections provided on the ball head are designed to be spherical cap-shaped in accordance with claim 12.

A low-production design of the pin provides according to claim 13, that the pin is continuous, but with the exception of its spherical cap end portions, continuously cylindrical, so that the mentioned cylindrical surface areas are set in their matching diameters by the pin diameter so identical itself. The total length of the pin is determined according to claim 14 by the radial distance of the groove bases, which is larger by only a tight play of movement than the externally measured over the spherical cap-shaped ends of the pin length pin.

The pin can be enclosed by the through hole in the ball head in the tight fit, but preferably it is taken in accordance with claim 15 in the sliding seat in the through hole, which offers the advantage that during insertion of the pin in the through-hole does not have to be paid attention to exact and tolerant low matching axial projection dimensions. When inserting the ball head in the receiving portion of the axially displaceable in the through hole of the ball pin according to the position of the groove bases to a certain extent automatically on the correct axial projection dimensions.

The axial securing of the ball head after its introduction into the receiving section is carried out according to claim 16.

As stated in claim 17, the ball head is associated with the mounting portion of the clamping assembly, while the receiving portion is associated with the clamping portion of the clamping assembly. In this case, according to claim 18, a releasable attachment of the clamping assembly to the relevant holding shaft can be effected by means of a latching device on the fastening section. The rotational drive through this support shaft is used according to claim 19, an end mounted on the mounting portion groove, in which a guided by the support shaft cross pin rotatably and play.

As stated in claim 20, the clamping portion for frictional engagement on the optical lens on a coating, which consists of a comparatively softer material than the lens to avoid damage to the lens surface in the lens feeding, edge processing and lens removal.

Preferably, according to claim 21 further comprises a specially trained adhesive film portion is provided with which the block piece and the optical lens for the edge processing operation can be releasably but rotatably connected to each other. In this case, the adhesive film section equipped on both sides is differently configured with regard to the adhesive adhesion forces of its two adhesive layers, so that the adhesion force on the side of the adhesive film section facing the block piece is higher than on the lens side. In this way, upon removal of the lens, it is ensured that the adhesive sheet portion remains releasably adhered to the block piece and thus need not be removed from the lens surface, which could cause surface damage to the lens or adhesive residue on the lens. For ease of removability of the adhesive sheet portion from the block piece, according to claim 22, on the adhesive sheet portion, there may be provided a tab projecting over the outer periphery of the block piece, which is at least non-adhesive on its optical lens side to avoid adhesion to the lens.

The adhesive film portion may be made extremely thin in the present arrangement as compared with the prior art. According to claim 23, it has only a thickness between about 0.025 and 0.2 mm, compared to a conventional Thickness of about 0.5 to 0.8 mm. Because of this very small thickness, which is made possible due to the elastic deformability of the block piece as described with respect to claims 5 and 6, no deformations or flexing phenomena occur in the adhesive sheet portion due to the applied torsional forces.

Fig. 1

eine perspektivische Explosionsdarstellung einer erfindungsgemäßen Anordnung zum Blocken und Spannen eines am Rand zu bearbeitenden Brillenglases, die von unten nach oben einen an einer schematisch dargestellten unteren Haltewelle montierten Blockstückadapter, ein Blockstück, einen Klebefolienabschnitt, das Brillenglas sowie eine an einer schematisch dargestellten oberen Haltewelle montierte Spannbaugruppe zeigt,

Fig. 2

eine Schnittansicht der in Fig. 1 dargestellten Anordnung in Funktionslage,

Fig. 3

eine Schnittansicht der Spannbaugruppe gemäß Fig. 2 in einem gegenüber der Fig. 2 vergrößerten Maßstab,

Fig. 4

eine Schnittansicht entsprechend der Schnittverlaufslinie IV-IV in Fig. 3 in einem gegenüber der Fig. 3 verkleinerten Maßstab,

Fig. 5

eine aufgebrochene Seitenansicht des am Blockstückadapter gemäß Fig. 2 montierten Blockstücks gemäß Fig. 2 in einem gegenüber der Fig. 2 vergrößerten Maßstab,

Fig. 6

eine Unteransicht des in Fig. 5 gezeigten Blockstücks in einem gegenüber der Fig. 5 etwas vergrößerten Maßstab,

Fig. 7

eine Schnittansicht des Blockstücks entsprechend der Schnittverlaufslinie VII-VII in Fig. 6 in einem gegenüber der Fig. 6 etwas vergrößerten Maßstab,

Fig. 8

eine Draufsicht auf den in Fig. 5 gezeigten Blockstückadapter in einem gegenüber der Fig. 5 etwas vergrößerten Maßstab,

Fig. 9

eine Schnittansicht des Blockstückadapters entsprechend der Schnittverlaufslinie IX-IX in Fig. 8, die in der Zeichnungsebene um 90° im Uhrzeigersinn gedreht wurde,

Fig. 10

eine Draufsicht auf den Klebefolienabschnitt gemäß Fig. 1 in einem gegenüber der Fig. 1 vergrößerten Maßstab und

Fig. 11

eine schematische abgebrochene Querschnittsansicht des Klebefolienabschnitts gemäß Fig. 10 in einem stark vergrößerten Maßstab.

In the following the invention with reference to a preferred embodiment with reference to the accompanying, partially schematic drawing will be explained in more detail. Show:

Fig. 1

an exploded perspective view of an inventive arrangement for blocking and clamping a to be processed on the edge of the spectacle lens from bottom to top mounted on a schematically illustrated lower support shaft block piece adapter, a block piece, an adhesive sheet, the lens and a mounted on a schematically illustrated upper support shaft clamping assembly shows,

Fig. 2

a sectional view of in Fig. 1 illustrated arrangement in functional position,

Fig. 3

a sectional view of the clamping assembly according to Fig. 2 in one opposite Fig. 2 enlarged scale,

Fig. 4

a sectional view corresponding to the section line IV-IV in Fig. 3 in one opposite Fig. 3 reduced scale,

Fig. 5

a broken side view of the block piece adapter according to Fig. 2 mounted block piece according to Fig. 2 in one opposite Fig. 2 enlarged scale,

Fig. 6

a bottom view of the in Fig. 5 Blockstücks shown in a relation to the Fig. 5 slightly enlarged scale,

Fig. 7

a sectional view of the block piece corresponding to the section line VII-VII in Fig. 6 in one opposite Fig. 6 slightly enlarged scale,

Fig. 8

a top view of the in Fig. 5 shown Blockstückadapter in a relation to the Fig. 5 slightly enlarged scale,

Fig. 9

a sectional view of the block piece adapter according to the section line IX-IX in Fig. 8 which has been rotated 90 ° clockwise in the plane of the drawing,

Fig. 10

a plan view of the adhesive film portion according to Fig. 1 in one opposite Fig. 1 enlarged scale and

Fig. 11

a schematic broken cross-sectional view of the adhesive film portion according to Fig. 10 on a much larger scale.

Like from the Figures 1 and 2 be found on the arrangement for blocking and clamping a to be processed at the edge of the lens L two rotatably mounted (not shown bearing) holding shafts 10 and 12 in the preferred vertical functional and processing position provided between their associated and to be described later assemblies and Elements of the lens L is arranged. In this case, care must be taken to ensure that slippage of the spectacle lens L clamped between the holding shafts 10 and 12 is reliably avoided in edge processing. Such For example, slippage must never occur if the spectacle lens to be machined has a near-end aligned with respect to the optical axis or a cylindrical or prismatic grinding whose axial position must be in a predetermined relationship to the position of the spectacle lens mounted in the spectacle frame.

The lower support shaft 12 is rigid, rotatably and coaxially connected to a Blockstückadapter 18, which is formed in a manner to be described for rotational angle oriented rotational drive of a block piece adapter 18 removably mounted block member 14. The block piece 14 is detachably attachable to one side 16 of the optical lens. On the upper support shaft 10, a clamping assembly 20 is coaxially mounted, which has a rigidly connectable to the support shaft 10 mounting portion 22 and an associated clamping portion 24. The clamping portion 24 is designed for frictional engagement with the other side 26 of the optical lens L.

The clamping assembly 20, whose details in particular from the FIGS. 3 and 4 clearly shows, has a provided on opposite sides in each case with a projection 28 ball head 30. This is received in a receiving portion 32 and is supported at the bottom of a truncated cone-shaped ball bearing surface 33 from. This can also be shaped as a spherical shell section. The receiving portion 32 is provided on opposite sides with parallel to the rotation axis D extending grooves 34, which serve the substantially rotational play-free guidance of the projections 28. The clamping portion 24 is with respect to the mounting portion 22 about a perpendicular to the rotational axis D of the ball head 30 and coaxially extending through the projections 28 first tilt axis A and about a pivot axis of the ball head 30 and the first tilt axis A perpendicular second tilt axis B gimbaled.

The introduced via the support shaft 10 torque is transmitted via the projections 28 from the mounting portion 22 to the clamping portion 24.

The provided on the ball head 30 projections 28 are formed by a pin 36 which extends through a through hole 38 in the ball head 30 therethrough. Each of the two protrusions 28 provided on the ball head 30 has a cylindrical surface area 40 projecting from the through-bore 38. The grooves 34 in the receiving portion 32 each have two opposing planar guide surfaces 42 which are parallel to each other of the substantially play-free guidance of the cylindrical surface portions 40 of the projections 28 serve. This guide is not lost during pivotal movements about the second tilt axis B within the limits of the expected pivoting movements.

Each of the protrusions 28 provided on the ball head 30 has an end region 44, which is designed in the shape of a spherical cap. How out Fig. 4 As can be seen, has the groove bottom 46 of each of the two provided in the receiving portion 32 grooves 34 seen in cross-section to the spherical cap end portion 44 of the associated projection 28 complementary shape. The end portions 44 of the projections 28 have a spherical radius which is identical to the radius of the cross section of the pin 36, ie the end portions 44 adjoin the pin 36 steplessly, including the cylindrical surface portions 40.

Notwithstanding the illustrated preferred embodiment, the grooves 34 may also have a rectangular cross-section, wherein the groove width is only a small amount of movement greater than the diameter of the cylindrical surface portions 40 of the projections 28. In this case, the groove side walls form the guide surfaces 42 Ball radii of the end areas 44 may not coincide with the radius of the cylindrical surface portions 40 and the radius of the cross section of the pin 36, but may be greater than this. It is merely necessary to ensure that the length of the pin 36, measured over the end regions, is less than the distance between the groove bottoms of the rectangular grooves due to a play of play. The spherical radius of the end portions 44 should be less than half the pin length.

The pin 36 has a cylindrical base body 48 forming the cylindrical surface regions 40 of the projections 28. This cylindrical body 48 is provided on both sides with the spherical cap-shaped end regions 44. The pin 36 has a length which is smaller by a movement play than the diametrically measured distance of the groove bottoms 46. The pin 36 can be accommodated axially displaceably in the through hole 38 in the ball head 30.

The receiving portion 32 for the ball head 30 is provided on the clamping portion 24 of the clamping assembly 20. The ball head 30 is as best as possible Fig. 3 emerges, held in the receiving portion 32 by means of a ball head 30 engaging behind two-piece locking ring 50. The two-part circlip 50 rests on an interrupted by the grooves 34 annular shoulder 51 of the ball head 30 in its lower portion 53 closely but with movement play surrounding stepped bore 35 in the receiving portion 32 (FIGS. Fig. 4 ). The two-part locking ring 50 is in turn held by a snap ring 55 which engages in an annular groove 57 of the stepped bore 35. In the arrangement shown, the ball head 30 is part of the fastening portion 22 and thus integrally formed.

The fastening portion 22 of the clamping assembly 20 has a latching device 52, by means of which the clamping assembly 20 releasably latched to the corresponding support shaft 10 ( Fig. 2 . 3 ). In the example shown is the locking device 52 a transversely inserted into a bore 90 of the mounting portion 22 cylinder sleeve 92 from which on both sides captive detent balls 94 protrude, which are acted upon by a spring assembly (not shown) within the cylinder sleeve 92 divergently. The detent balls 94 protrude beyond the outer circumference of the cylindrically shaped fastening section 22, so that they can be latched with a detent groove 96 in the interior of a blind bore 98 of the retaining shaft 10 which accommodates the fastening section 22 ( Fig. 2 ).

The attachment portion 22 of the clamping assembly 20 is provided at the end with a groove 54, in which a transverse pin 100 engages the positive rotational driving by the support shaft 10, which is inserted into a transverse bore of the support shaft 10. Rotations of the support shaft 10 are thus transmitted via the transverse pin 100 on the mounting portion 22 and from this via the engagement of the projections 28 with the grooves 34 on the clamping portion 24th

The clamping portion 24 has for frictional attack on the optical lens L a coating 56 which is formed annular in the example shown. It consists of a material that is soft in relation to the material of the optical lens L, such as leather or artificial leather. The pad may be connected to the lower surface of the clamping portion 24 by gluing. If an injection-moldable polymeric material is used for the coating 56, this can also on its upper side with projections or the like. for positive engagement with corresponding depressions or the like. the lower surface of the clamping portion 24 may be formed (not shown). It is essential that the covering with respect to the optical lens has a good adhesion for transmitting the torque and that the coating no damage to the lens surface or thin layers applied to them, such as anti-reflective coatings.

A U-ring seal 102 in the form of an O-ring provides a seal between the mounting portion 22 and the support shaft 10. It seals these elements in the lower region of the blind bore 98 from each other. As in Fig. 2 indicated in dash-dotted lines, the support shaft 10 and the clamping portion 24 may be connected by a tubular or tubular flexible sleeve 104 with each other. Because of its flexibility, this sleeve does not interfere with cardanic movements of the tensioning section 24 relative to the support shaft 10, however, it effectively seals the receiving section 32 against the ingress of contaminants such as grinding dust. In addition, the cuff 104, especially if made of rubber or an elastomeric plastic, tends to occupy its elongated hollow cylindrical position, thereby exerting a pre-centering action on the biasing portion 24 against engagement with the optical lens L.

For a more detailed explanation of the block piece 14, the block-piece adapter 18 and their mutual assignment and their connection to the lower support shaft 12 is now on the Figures 1 and 2 in conjunction with the FIGS. 5 to 9 Referenced.

For the positive rotational drive of the block member 14 by the block adapter 18, these parts each have in the example toothed rotary driving elements, which will be described in more detail below. Furthermore, block piece 14 and block piece adapter 18 also each have positioning elements described in greater detail below, which have the task of orienting and / or positioning block piece 14 and block piece adapter 18 in an angle of rotation relative to one another prior to engagement of the rotary drive elements.

The positioning elements consist of a plurality of asymmetrically arranged projections 58 and a plurality of complementary associated correspondingly asymmetrically arranged recesses 62. The projections 58 may be arranged either on the block piece 14 or on the block piece adapter 18. The same applies to the recesses 62, i. when the protrusions 58 are on the block piece 14, the recesses 62 are disposed on the block piece adapter 18. If, on the other hand, the projections 58 are located on the block piece adapter 18, the cutouts 62 are arranged on the block piece 14. Preferably, and as shown, the protrusions 58 are formed on the block piece adapter 18, while the recesses 62 are provided on the block piece 14.

The end faces 60 of the projections 58 lie in a plane perpendicular to the axis of rotation D common plane ( Fig. 8, 9 ). The recesses 62 start from a plane perpendicular to the rotation axis D flat surface 64 ( Fig. 5, 6, 7 ). In this case, the arrangement is such that the block piece 14, the axial distance a ( Fig. 7 ) between the rotary driving elements and the positioning elements, ie the flat surface 64, from which the recesses go, different, ie greater, than the block piece adapter 18, the axial distance b ( Fig. 9 ) between the rotary driving elements and the positioning elements, ie the common plane of the end face 60 of the projections 58th

Due to these conditions, the block piece 14 can be in the following manner with the block piece adapter 18 to the in Fig. 5 unite desired angle-correct engagement situation shown. If the block piece 14 moves axially toward the block piece adapter 18, the protrusions 58 with their end faces 60 first come into abutment with the flat surface 64, if the rotational angle orientation of the block piece and block piece adapter is not yet given. Now the block piece 14 is brought about to bring about the sole correcting angle orientation rotated relative to the Blockstückadapter 18, wherein the end faces 60 slide on the flat surface 64, without causing the block piece 14 relative to the Blockstückadapter 18 performs a tilting movement, which could undesirably bring the rotary driving elements partially engaged. Due to the matching unbalanced arrangement of the projections 28 and the recesses 62, only a correct rotational angle orientation is possible. When the correct relative rotational angle orientation between block piece 14 and block piece adapter 18 is reached, the projections 58 enter the recesses 62 upon further axial approach, whereupon the mutually toothed rotary driving elements finally engage each other in the inward slots Fig. 5 engage shown engagement, so that torques from the support shaft 12 to the block piece 14 are transferable. Moreover, in such arrangements, the two support shafts 10 and 12 are driven synchronously at the same speed.

To achieve the temporary tilt-proof installation of the end faces 60 on the flat surface 64, the three projections 58 provided in the exemplary embodiment and, of course, also the recesses 62 form the vertices of a triangle. It should be ensured, however, that it is not an equilateral triangle, if its vertices of the axis of rotation have the same radial distance, because it would be possible in an undesirable manner three different mutually 120 ° rotational angle offset engagement positions. The projections and the recesses should have different radial distances in asymmetrical arrangement of the axis of rotation.

To facilitate the insertion of the projections 58 into the recesses 62, the projections 58, starting from their end faces 60 and / or the recesses 62 starting from the flat surface 64 bevels 66. Chamfers at the inlet openings of the recesses 62 are not shown in the drawings.

The block piece 14 has, as best of Fig. 7 shows a hub portion 68, on which the positioning elements are provided, ie. The outgoing from the flat surface recesses 62nd

To the hub portion 68 elastically connected to a concentric annular portion 70 which carries the toothed rotary driving elements. The elastic connection between the hub portion 68 and the ring portion 70 assume in the example shown ( Fig. 6 ) four evenly distributed on the circumference webs 72, which are integrally connected both to the ring portion 70 and with the hub portion 68. This one-piece is easily achieved when the block piece 14 is injection molded overall of a flexible thermoplastic PU-based (eg Elastollan). Instead of the webs 72 but can also be provided between the hub portion 68 and the ring portion 70, a thin-walled elastic circumferential connecting wall (not shown). This then occurs instead of existing between the webs 72 gap 73.

As in particular from the FIGS. 6, 7 and 8, 9 As can be seen, the rotary driving elements on the block piece 14 and on the block piece adapter 18 are formed by complementary ring teeth 74 and 76, respectively. These ring gears 74 and 76 are slightly conical, namely on the block piece 14 convex-conical and the block piece adapter 18 concave-conical. In this way, the ring gears 74 and 76 exhibit, when engaged, a centering action with respect to the common axis of block piece 14 and block piece adapter 18.

The Blockstückadapter 18 has a sleeve-shaped rotationally symmetrical made of metal, such as brass, body 106, which is provided with a central receiving bore 108 for the in diameter adapted shaft end 110 ( Fig. 2 ) of the support shaft 12 is provided. The rotationally fixed and rotationally correct connection of the body 106 with the shaft end 110 assumes a transverse pin 112, which engages in a transverse bore 114 of the shaft end 110 and at the same time in a driving recess 116 of the body 106. The driving recess 116 is the cross pin 112 adapted so closely that the body 106 after attachment of the transverse pin 112 can not rotate relative to the support shaft 12. It is only provided a driving recess 116, so that the block piece adapter 18 can be attached to the support shaft 12 only in a rotational angular position.

Attached to the body 106, for example molded thereon, is an externally conically shaped receiving element 118 for the block piece 14. The receiving element 118 is molded from a hard thermoplastic, such as polyoxymethylene (POM), and has a cylindrical receiving bore 120 for the hub portion 68 of FIG Block piece 14. The upper edge of the receiving element 118 is formed to form the ring gear 76. The receiving bore 120 terminates at an aligned perpendicular to the rotation axis D inner surface 122, from which the projections 58 go out.

The block piece 14 can be attached to the optical lens L by means of a double-sided adhesive film section 78. The adhesive film portion 78 serves to block the lens L by means of the block piece 14 and is located after the blocking and clamping between the block piece 14 and the lens L, as shown in FIGS Figures 1 and 2 evident. The peculiarity of the adhesive film section 78 is that the adhesive applied to its side facing the block piece 14 has a higher adhesive force than the adhesive applied to its side L facing the lens L (US Pat. Fig. 11 ) an undesirable stronger adhesion to the optical lens L is avoided.

The in Fig. 10 shown adhesive film portion 78 which has approximately a circular outer contour with an approximately the outer diameter of the annular portion 70 of the block piece 14 corresponding diameter is provided with a removal facilitating tab 84 which is non-adhesive at least on its side facing the lens L, so that they can not adhere to the lens L.

Due to the elasticity of the lens L facing support surface 86 (FIG. Fig. 1 . 7 ) of the block piece 14, the adhesive sheet portion 78 may have a very small thickness between about 0.025 and 0.2 mm, because the adhesive sheet portion does not have to perform any tasks of conforming to the curved surface of the lens L because of the mentioned elasticity of the block piece 14. The transmitted torque can not deform or walk the very thin adhesive film portion.

Proposed is an arrangement for blocking and clamping of lenses to be processed on the edge, in particular spectacle lenses, which improves in handling and which is optimized in terms of a virtually backlash-free rotational drive of the optical lens. For this purpose, the arranged between the two support shafts elements, in particular the clamping assembly, the block piece with the Blockstückadapter and the adhesive connection between the block piece and the optical lens are designed in a special way.

LIST OF REFERENCE NUMBERS

10

holding shaft

12

holding shaft

14

block piece

16

one side of the optical lens

18

Block piece Adapter

20

tension assembly

22

attachment section

24

clamping section

26

the other side of the optical lens

28

head Start

30

ball head

32

receiving portion

33

Ball bearing surface

34

groove

35

stepped bore

36

pen

38

Through Hole

40

area

42

guide surface

44

end

46

groove base

48

body

50

circlip

51

annular shoulder

52

locking device

53

lower region of the stepped bore 35

54

groove

55

snap ring

56

covering

57

ring groove

58

head Start

60

face

62

recess

64

flat surface

66

chamfer

68

hub portion

70

ring section

72

web

73

gap

74

ring gear

76

ring gear

78

Adhesive film section

80

the block piece facing side

82

the lens facing side

84

flap

86

bearing surface

90

drilling

92

cylinder sleeve

94

detent ball

96

locking groove

98

blind hole

100

cross pin

102

groove ring seal

104

cuff

106

body

108

location hole

110

shaft end

112

cross pin

114

cross hole

116

driving cutout

118

receiving element

120

location hole

122

palm

a

axial distance

b

axial distance

A

first tilt axis

B

second tilt axis

D

axis of rotation

L

optical lens

Claims (23)

1. An arrangement for blocking and clamping optical lenses (L) requiring edge-machining, in particular spectacle lenses, between two rotatable holding shafts (10, 12), comprising
   a blocking member (14), which can be attached detachably to one side (16) of the optical lens (L),
   an adapter (18) for the blocking member (14), which can be connected rigidly to one of the holding shafts (12) and is constructed for rotation angle-oriented rotary drive of the blocking member (14), and
   a clamping assembly (20), which comprises a fastening portion (22) connectable rigidly to the other holding shaft (10) and a clamping portion (24) connected to the fastening portion (22), which clamping portion (24) is constructed for force-locking engagement with the other side (26) of the optical lens (L),
   wherein the blocking member (14) and the blocking member adapter (18) each comprise rotary drive elements for form-fitting rotary drive of the blocking member (14) by the blocking member adapter (18) and positioning elements for orientation with regard to angle of rotation of the blocking member (14) relative to the blocking member adapter (18),
   characterized in that the positioning elements on the blocking member (14) or on the blocking member adapter (18) take the form of a plurality of asymmetrically arranged projections (58), the end faces (60) of which lie in a common plane perpendicular to the axis of rotation (D), while the positioning elements on the blocking member adapter (18) or on the blocking member (14) take the form of recesses (62) associated in complementary manner with the projections (58), said recesses (62) starting from a flat surface (64) perpendicular to the axis of rotation (D),
   wherein the axial distance (a) between the rotary drive elements and the positioning elements on the blocking member (14) is different from the axial distance (b) between the rotary drive elements and the positioning elements on the blocking member adapter (18), such that, if the blocking member (14) is moved axially towards the blocking member adapter (18) and rotation angle orientation has not yet been achieved, first of all the projections (58) come to rest against the flat surface (64) and then, once rotation angle orientation is complete, the projections (58) enter into the recesses (62), whereupon the rotary drive elements come into engagement with one another.
2. The arrangement according to claim 1, characterized in that three projections (58) are provided, the end faces (60) of which form the corners of a triangle.
3. The arrangement according to claim 1 or 2, characterized in that the projections (58) and/or the recesses (62) exhibit bevels (66) starting respectively from the end faces (60) of the former or the flat surface (64).
4. The arrangement according to one of the preceding claims, characterized in that the projections (58) are formed on the blocking member adapter (18), while the recesses (62) are provided on the blocking member (14).
5. The arrangement according to one of the preceding claims, characterized in that the blocking member (14) has a hub portion (68), on which the positioning elements are provided, and an annular portion (70) which is connected resiliently with the hub portion (68) and bears the rotary drive elements.
6. The arrangement according to claim 5, characterized in that the hub portion (68) is connected preferably in one piece with the annular portion (70) via a plurality of webs (72) distributed evenly around the circumference.
7. The arrangement according to one of the preceding claims, characterized in that the rotary drive elements are formed on the blocking member (14) and on the blocking member adapter (18) by complementary annular toothing (74, 76).
8. The arrangement according to one of the preceding claims, characterized in that the clamping assembly (20) has a spherical head (30) provided on each of its opposing sides with a projection (28), which spherical head (30) is accommodated in a receiving portion (32), which is provided on opposing sides with grooves (34) extending parallel to the axis of rotation (D) of the receiving portion (32), which grooves (34) serve for substantially rotary play-free guidance of the projections (28), for which a groove bottom (46) of each of the grooves (34), when viewed in cross section, has a shape complementary to an end zone (44) of the associated projection (28), wherein the clamping portion (24) can be swivelled relative to the fastening portion (22) about a first tilt axis (A) perpendicular to the axis of rotation (D) of the spherical head (30) and extending through the projections (28) and about a second tilt axis (B) perpendicular to the axis of rotation (D) of the spherical head (30) and to the first tilt axis (A), while torque can be transmitted via the projections (28) from the fastening portion (22) to the clamping portion (24).
9. The arrangement according to claim 8, characterized in that the projections (28) provided on the spherical head (30) are formed by a pin (36) which extends through a through-hole (38) in the spherical head (30).
10. The arrangement according to claim 8 or 9, characterized in that each projection (28) provided on the spherical head (30) comprises a cylindrical surface zone (40).
11. The arrangement according to claim 10, characterized in that the grooves (34) in the receiving portion (32) each comprise two flat guide surfaces (42), which guide surfaces (42) extend parallel to one another and serve in substantially play-free guidance of the cylindrical surface zones (40) of the projections (28) provided on the spherical head (30).
12. The arrangement according to one of the claims 8 to 11, characterized in that the end zones (44) of the projections (28) provided on the spherical head (30) take the form of a spherical segment.
13. The arrangement according to claims 9 to 12, characterized in that the pin (36) has a cylindrical basic member (48) forming the cylindrical surface zones (40) of the projections (28), which basic member (48) is provided at both sides with the spherical segment-shaped end zones (44).
14. The arrangement according to one of the claims 9 to 13, characterized in that the pin (36) exhibits a length which corresponds substantially to the spacing of the groove bottoms (46) .
15. The arrangement according to one of the claims 9 to 14, characterized in that the pin (36) is accommodated in axially displaceable manner in the through-hole (38) in the spherical head (30).
16. The arrangement according to one of the claims 8 to 15, characterized in that the spherical head (30) is held in the receiving portion (32) by means of a two-part retaining ring (50) engaging behind the spherical head (30).
17. The arrangement according to one of the claims 8 to 16, characterized in that the spherical head (30) is a component of the fastening portion (22) of the clamping assembly (20), while the receiving portion (32) for the spherical head (30) is provided on the clamping portion (24) of the clamping assembly (20).
18. The arrangement according to one of the claims 8 to 17, characterized in that the fastening portion (22) of the clamping assembly (20) comprises a locking means (52), by means of which the clamping assembly (20) can be locked detachably together with the corresponding holding shaft (10).
19. The arrangement according to one of the claims 8 to 18, characterized in that the fastening portion (22) of the clamping assembly (20) is provided at the end with a groove (54) for form-fitting rotary drive by the corresponding holding shaft (10).
20. The arrangement according to one of the claims 8 to 19, characterized in that the clamping portion (24) comprises a covering (56) for force-locking engagement with the optical lens (L), which covering (56) consists of a material, such as leather or synthetic leather, which is softer than the material of the optical lens (L).
21. The arrangement according to one of the preceding claims, characterized in that the blocking member (14) can be attached to the optical lens (L) by means of an adhesive film portion (78) adhesive on both sides, which exhibits greater adhesive power on the side (80) thereof facing the blocking member (14) than on the side (82) thereof facing the optical lens (L).
22. The arrangement according to claim 21, characterized in that the adhesive film portion (78) is provided with a tab (84), which is non-adhesive at least on the side thereof facing the optical lens (L).
23. The arrangement according to claim 21 or 22, characterized in that the adhesive film portion (78) exhibits a thickness of between 0.025 and 0.2 mm.

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