DE102004016445B4 - Device for holding spectacle lenses and other shaped bodies with optically effective surfaces during processing - Google Patents

Abstract

A device for holding spectacle lenses and other optically active surfaces when machining, comprising a housing (1, 9) having a holder (22) for a workpiece to be machined (11), wherein between an upper housing part (9) and a An intermediate ring (8) is provided with the housing lower part (1) screwed to it, on which axially movable support body (32; 34; 10) can be fixed in a compressed air-actuated manner by means of a radially acting rubber sleeve (15), characterized
• that the intermediate ring (8) together with a membrane (4) between the lower housing part (1) and the upper housing part (9) is axially clamped,
That in the intermediate ring (8) a cylindrical support body (2; 34; 10) seated on the membrane (4) is guided in an axially movable manner,
• that in the upper housing part (9) has a radially acting rubber sleeve (23) for the compressed air-actuated fixing of the holder (22) is present, and
• that compressed air channels (17; 20; 26 ... 29) from the lower housing part (1) in a cavity (18) under the diaphragm (4) and in the rubber sleeves (15;

Description

The The invention relates to a device for holding spectacle lenses and with other moldings optically effective surfaces (eg lenses or concave mirrors) when editing, according to the in the preamble of claim 1 mentioned features. It is about preferably in the manufacture of spectacle lenses.

The lenses and other shaped bodies mentioned here consist predominantly of plastics which have a low specific weight at a high refractive index and are easy to machine and polish. The following important requirements apply to the production processes of modern ophthalmic lenses and molded articles:
A so-called thickness optimization must be possible (lens as thin as possible), with which the weight of the lenses and moldings is minimized. This improves the performance characteristics of all devices in which these optical components are incorporated (eg in eyeglasses binoculars, etc.). A low weight is the consumer's utmost care today.

This especially applies to Glasses in which the weight depends essentially on the lenses. light lenses made of plastic, which takes into account the thickness optimization therefore contribute significantly to the increased wearing comfort and are preferred today.

to Linguistic simplification will be used instead of eyeglass lenses and below other moldings with optically effective surfaces only from spectacle lenses spoken. But are always synonymous "other moldings with optically effective surfaces. "Only when it is off The factual context is necessary, is still on Lenses or other shaped bodies with optically effective surfaces pointed.

There the optical properties of spectacle lenses u. a. from their two curved surfaces and whose distance is determined, this can be greater or made smaller be without affecting the optical properties of the lens change, if the surface geometries match be adjusted. Of these physical conditions is at the thickness optimization made use of. The surface geometries are calculated so that as thin as possible lens the required optical properties are given.

at Plus glasses (Lens center is thicker than the lens edge) and neutral lenses (lens center is the same thickness as the lens edge) is in the thickness optimization the Thickness of the lenses is reduced as much as this with regard to remaining edge thickness (= thickness at the peripheral edge of the finished spectacle lens) is possible. The edge thickness must be kept, so that the lens in the spectacle frame can be properly mounted, d. H. this thickness must be about the same Width of the frame correspond to the spectacle frame.

at Minus lenses (Lens center is thinner than Lens edge) is in the context of thickness optimization, the thickness of the lenses reduced as far as this in view of the remaining residual thickness possible in lens center is. A certain minimum thickness in the center of the lens is required thus the mechanical stability of the spectacle lens not inadmissible decreases.

In the production of spectacle lenses, taking into account the aforementioned thickness optimization, the following problem arises:
Through the thickness optimization (spectacle lens as thin as possible) and the plastics used as lens material (low strength), the spectacle lenses produced become increasingly unstable during the exciting production. As they become thinner due to the removal of material, they lose stability and give way to the pressure of the processing tools, which leads to undesirable changes in the surface geometry. In this context, clamping tools and procedures had to be found which counteract the instability mentioned.

devices and method for preventing the instability of thin spectacle lenses during the Machining are known per se, but have a number of disadvantages on.

So z. B. in the DE 40 03 002 A1 a method for the production of spectacle lenses described in which the lenses are blocked before processing. This refers to the attachment of the cast or pressed plastic blank (semi-finished part) to a so-called block piece by means of Woodchem metal.

With the block piece the plastic blank is then attached to the workpiece spindles of the various Machine tools attached and the lens through exciting Machining produced, with a thickness optimization takes place.

• – Das Aufblocken mit Woodschem-Metall ist ein aufwendiger, teurer Arbeitsschritt und eignet sich nur bedingt für automatische Fertigungsverfahren.
• – Das Woodsche-Metall enthält gesundheitsschädliche Bestandteile (z. B. 12,5 % Cadmium) und ist daher nur unter Einhaltung besonderer Schutzmaßnahmen zu verarbeiten.
• – Beim Auf- und Abblocken gehen ca. 10 % des Metalls verloren. Bei einer jährlichen Fertigungsmenge von weltweit einigen 100 Millionen Brillengläsern stellt dies nicht nur einen erheblichen Kostenfaktor dar, sondern ist auch ein großes Umweltproblem.

Due to the fact that the blocked lens is supported flat by the wood-metal, no stability problems arise even with very thin spectacle lenses. The blocking method described above and the devices used as in DE 40 03 002 A1 but have a number of other disadvantages:

• - Blocking with Woodschem metal is a complex, expensive operation and is only partially suitable for automatic manufacturing processes.
• - The Woodsche metal contains harmful components (eg 12.5% cadmium) and must therefore only be processed in compliance with special protective measures.
• - When blocking and blocking, about 10% of the metal is lost. With an annual production of some 100 million spectacle lenses worldwide, this not only represents a significant cost factor, but is also a major environmental problem.

Another method is used in the DE 100 36 158 C1 proposed, which works without blocking, but provides that the lenses must be cut in the course of processing and welded together again.

Here In connection with the thickness optimization the problems occur the instability of thin lenses. It is therefore envisaged that in this method, an outer, thicker clamping edge while the processing stops, with which the spectacle lens tightened and to be mechanically stabilized in some areas.

to Production of the spectacle lenses The plastic blanks are stretched at the edge and first the processed convex front of the lens. At the half-finished workpiece then has the back to be edited.

In order to the workpiece it does not lose its clamping edge and its mechanical strength provided, the half-finished spectacle lens initially along its final outer contour Cut out (circumference) from the edge region of the workpiece, including a Laser should be used.

To an axial displacement of the half-finished spectacle lens relative to the left outer ring of the plastic blank by a few millimeters, it will be in this position with the outer ring re-welded by laser.

The workpiece let yourself then continue on the outer clamping edge clamps and is intended by this for the processing of the lens backside mechanically be stabilized.

Although that in the DE 100 36 158 C1 described methods and the devices used some disadvantages of the DE 40 03 002 A1 However, in the context of the proposed method, another disadvantage arises:
Since the thin spectacle lens is clamped by means of its circular clamping edge (outer ring) in the chuck of the machine without further support, while a secure clamping is ensured, the thin lens can, however, bend in its central (inner) area under the pressure of the tools, there is no support there.

The aforementioned problems with the deflection of thin spectacle lenses due the lack of stability Join here despite the elaborate Laser processing on. The deflection leads to inaccuracies the processing and thus to a reduction in the optical quality of the spectacle lens.

In another, under the file number DE 103 10 561 B4 proposed method, the disadvantages associated with the deflection of the lens during processing due to too low stability also occur.

The The basic principle of this method is that the plastic blanks while all processing steps on the outer, circular circumference be tense and the exciting process is conducted, that an annular area on the outer circumference is maintained, whose thickness is approximately that of the plastic blank equivalent.

First if all operations (Milling, Turning, fine grinding, if necessary polishing, marking and coating) finished are, the actual lens from the outer, annular area separated.

Thereby, that on the outer circumference of the workpiece said annular Range in approximate full thickness of the plastic blank is preserved during the entire machining a suitable circular clamping surface for Available.

Of the annular Area is because of its large Thickness and also because of its circular ring shape mechanically stable and therefore able to be firmly attached to it in its inner area Support the lens in the edge area. For the central (inner) area of the spectacle lens, however, this does not apply.

Of the Disadvantage of the method described here and the used Devices is therefore the said instability of the lenses during the Processing.

Since the thin spectacle lens is clamped only by means of its annular portion and without further support in the chuck of the machine, it can durchbie in its central region under the pressure of the tools The deflection mentioned leads to inaccuracies in the machining and thus to a reduction in the optical quality of the spectacle lens.

Under the file number DE 103 15 008 A1 . DE 103 32 673 A1 and DE 103 38 893 A1 Three procedures were proposed, which are the procedure with the file number DE 103 10 561 B4 similar and accordingly have the same disadvantage.

Also stays here while the entire mechanical machining received an annular clamping edge, which should stabilize the lens. The clamping edge fulfills this Task in the central area of the lens but only inadequate. There are deflections in the processing of thin lenses with the resulting disadvantages for the quality.

DE 101 06 007 A1 discloses a device in which a work surface assumes the contour of the lens as a negative impression. The position of the work surface is fixed after removing the negative impression. This should prevent the above-mentioned problematic deflections of the lenses during processing. However, this does not succeed completely, whereby the quality of the spectacle lenses produced by this method has not yet been sufficiently improved.

Of the Invention is therefore the object of the quality of the generated lenses significantly improve, without causing disadvantages in terms of manufacturing costs or production times arise.

These Task is according to the invention with a Device of the aforementioned type with the characterizing features of claim 1. Advantageous embodiments result from the features of Dependent claims.

at the device according to the invention for holding spectacle lenses and other moldings provided with optically effective surfaces Editing with a case, that a holder for a workpiece to be machined having, between an upper housing part and one with him screwed housing base an intermediate ring is present, it is provided that on the intermediate ring axially movable support body by means a radially acting rubber sleeve can be fixed pneumatically operated are. Here is the intermediate ring together with a membrane between the Housing bottom and the upper housing part axially clamped. One sitting in the intermediate ring on the membrane cylindrical support body is thereby guided axially. In the upper housing part is a radial-acting rubber sleeve for air-operated fixation the bracket is present. Compressed air ducts lead from the lower part of the housing in a cavity under the membrane and in the rubber sleeves.

The inventive device comes in different milling, Turning, grinding and polishing machines used to glasses in these tighten. At the same time the lenses are supported in their center, so that unwanted deflection as a result of the transferring tool forces be avoided during processing.

The Device accordingly consists of a housing, the in its upper area over a tensioning device (collet) for tightening the lenses has, while in its inner area a support device is accommodated, whose support element engages from below on the clamped lenses and supports them so that there are no deflections during the Editing comes.

in the Subsequently, the device according to the invention is also as a feed designated. For attaching the receiving feed to the spindles of the Machine tools is in the lower part of the housing Cradle available.

It It is envisaged that the lenses with their outer, annular edge be tightened in the collet and then the support takes place in the central (inner) region of the thin spectacle lenses. For this purpose, the said support device with the axially displaceable support element present, which applies to the bottom of the lens. This is one of the essential ideas of the invention.

The inventive device with the spectacle lens clamped therein is at the workpiece spindles The various machine tools attached and also allowed a processing very thin Eyeglass without it being the unwanted Deflections come because the lens, as mentioned, is additionally supported. quality degradation as a result of such deflections therefore do not take place.

The receiving feed proposed here is particularly suitable for carrying out processes for the production of spectacle lenses, which are mentioned in the file reference DE 103 10 561 B4 . DE 103 15 008 A1 . DE 103 32 673 A1 and DE 103 38 893 A1 have become known. However, other methods with similar features for the application of the device according to the invention come into question.

The problems with deflections of the lenses due to lack of stability in the central region which occur in these methods can occur when using the receptacle according to the invention be avoided.

• – Es findet eine Dickenoptimierung statt, d. h. sehr dünne Brillengläser werden hergestellt, die bei der Bearbeitung im zentralen Bereich unterstützt werden sollten.
• – Während des gesamten Herstellungsprozesses bleibt an dem Werkstück (Brillenglas) ein äußerer, kreisringförmiger Rand erhalten, der sich gut in standardisierten Spannzangen festspannen lässt.

The four methods mentioned have, inter alia, two essential features:

• - Thickness optimization takes place, ie very thin spectacle lenses are produced, which should be supported during machining in the central area.
• - During the entire manufacturing process remains on the workpiece (spectacle lens) an outer, annular edge is obtained, which can be well clamped in standardized collets.

The both mentioned features of the method correspond to the properties of the food of the invention in an ideal way, so that it can be used to great advantage can. The tightening of the spectacle lens by means of the collet is simple and easy, the support device of the hostage ensures that it is not too unwanted Bending comes.

There the lenses in the central, to be supported Range, due to their different geometry, relative to Collet different heights must have the support element the support device movable be, so that it can adapt to these different altitudes.

For this it is provided that the support body (hereafter also as a support element designated) is arranged axially displaceable in the housing and via a Drive has, with which he can be moved so far, until it with the collet held spectacle lens comes into contact.

The Movement of the support element is preferably driven by compressed air. Also to drive the Collet is preferably compressed air used. The drives of the collet and the support element as well as the associated pressures are designed so that there is no contact with the spectacle lens damage or deformations comes.

If the contact between the spectacle lens and the support element is made, this is locked so that it can take over its support function. The purpose required locking device is also preferred with compressed air driven.

To the Driving the collet, the support element or the locking device can However, in place of the compressed air drives, other drives, eg. As electric drives are used.

For the execution of Device according to the invention There are several variants. Their structure is oriented the conditions of the lenses and lenses to be produced.

A Variant 1 has a particularly simple design and is suitable for machining of rotationally symmetrical lenses and spectacle lenses. The support element is designed as a cylinder whose diameter to be supported area the lens is adapted and at its upper end over a Recess has. Thus, there arises on its periphery a narrow edge, which differs from at the bottom against the lens or spectacle lens. The touch occurs circular ring and supported the central region of the lenses or lenses to be processed.

The cylindrical support element is located in the center of a housing, which is at its upper End carries a mechanically driven collet. The cylindrical support element is inside the case and possibly other structural elements arranged there axially slidably guided.

At the lower end of the cylindrical supporting member There is a membrane present when exposed to its outside with compressed air against the support element depressed is moved and this axially. For this purpose, the membrane is sealing in the interior of the housing attached.

The cylindrical support element is surrounded by a rubber sleeve, which acts on compressed air can be, wherein it expands and the cylindrical support member thereby locked in its position relative to the housing. To supply the Membrane, rubber sleeve and collet with compressed air serve different holes in the housing, with corresponding air channels in the Workpiece spindle the processing machine communicate.

in the lower area has the housing over facilities, by means of which it with the workpiece spindles the various processing machines can be connected.

The clamping of a lens or a spectacle lens in the receiving food according to the invention then takes place in the following steps:
The lens or the spectacle lens are inserted into the opened collet and then tightened there by applying pressure to the collet chuck. Subsequently, the membrane is subjected to compressed air and thereby applied the cylindrical support member with its outer support edge from below to be supported surface of the lens or the spectacle lens (annular contact surface).

To lock the support element is then Also, the rubber sleeve acted upon by compressed air, so that the support member is immovably fixed in the housing and can take over its support function. As mentioned, however, this is only possible with rotationally symmetrical lenses or spectacle lenses. For non-rotationally symmetrical spectacle lenses and possibly also other shaped bodies with optically active surfaces, two further variants of the receiving diet according to the invention are provided, wherein essentially the supporting devices vary.

A Variant 2 is used for clamping spectacle lenses, which are used in thickness optimization still a certain stability keep so that to avoid deflections during the Machining a punctiform support in the center of the lens is enough.

For this is provided that the support element consists of a single, rounded top pin, which is displaceable in the case is stored and create punctiform from below the spectacle lens can. This pin is preferably carried out with a circular cross-section (cylinder pin) and can be made of metal or plastic.

at a preferred embodiment the cylinder pin is attached to a piston which is axially displaceable in the case is stored. In its upper area, the housing carries the collet.

At the underside of the piston again lays a rubber membrane on whose outside can be acted upon with compressed air. Due to the larger diameter of the piston are enough small pressures out to the axial movement of the piston and cylinder pin upwards trigger. There, the cylinder pin lays from below to the center of the lens at.

to Locking the piston and thus the cylinder pin in this position, An inflatable rubber boot is provided which is wrapped around the piston is. To lock the piston, it is inflated with compressed air where it expands and clamps the piston.

Otherwise, this corresponds execution this variant 2 of those already described as in variant 1.

The execution with dowel pin is very simple and therefore inexpensive. issues result with the different geometries on the undersides of the lenses not because the cylindrical pin touches the lens there only punctiform and the shape of the spectacle lens is therefore not relevant. For spectacle lenses whose Thickness has not been extremely reduced, this type of support can be Center, for stabilization during the Processing sufficient.

at especially thin lenses with arbitrarily shaped surface geometry However, it is desirable these on one as possible to support large area evenly without that for each Geometry be made a specially shaped support element must, which would rest without gaps on the lens. Eyeglass lenses usually have a complicated, non-rotationally symmetric surface geometry, which is described by many parameters.

It Therefore, a variant 3 is provided, which corresponds to this requirement and about this a flexible support element features. The rest Structure corresponds to the versions, as already described in connection with variants 1 and 2.

There the lenses, as mentioned, very different surface geometries have (convex, concave, different radii of curvature), the support element must the support device be executed that it is the curvature the bottom of the lens can adjust. It has to be flexible be.

This is possible, if several cylindrical pins are accommodated in the housing, the all are mutually axially displaceable and together with their upper end side are pressed against the underside of the lens can. They place, according to the shape of the lens, different Ways back. The cylindrical pins can then be in be locked in this position and so with its upper end the lens support in many places. This is a nearly flat support of the spectacle lens.

It are also provided pins with other than circular cross-sections. For linguistic simplification, however, then only but still spoken of cylindrical pins, but always meant Pins with other cross sections.

At their respective upper and lower ends are the cylindrical pins each covered with a membrane of elastic material. In this elastic material can be z. B. rubber of suitable hardness, However, other materials come into question. To the linguistic Simplification is hereinafter only spoken of rubber meant however, there are always other materials with similar properties.

The membrane in the region of the spectacle lens (upper membrane) serves to protect the surface of the spectacle lens against scratching, if the cylindrical pins are made of metal. The upper mem At the same time, bran bridges the gaps between the pins so that a flat contact (support) of the spectacle lens is created without gaps.

The Upper membrane also prevents that from being processed lenses used liquids enters the area between the pins and there to corrosion or leads to a festering of the pens.

In its edge region is the upper membrane either directly with the casing connected or closed in the edge region of a hollow cylinder made of the same material, the then in turn by means of an annular flange on his other end to the case connected is. In this case, the cylinder pins are in the hollow cylinder accommodated.

The Membrane at the other end of the cylinder pins (lower membrane) is sealing in the housing installed, so that their underside are pressurized with compressed air can, without it comes to air losses.

Under the influence of the compressed air, the lower membrane bends through and moves the cylinder pins towards the lens. There they press the upper membrane for support to the bottom of the lens or ensure a safe Concerning the upper membrane on the spectacle lens, if this at Insert into the collet already in contact with the upper diaphragm got. As long as the lower membrane is not yet with compressed air is applied, the dowel pins can be when inserting the Press the spectacle lens lightly down into the collet.

Of the Pressure of the compressed air, to move the cylinder pins, must be so chosen be that it does not come to bending the lens when the cylindrical pins and the upper diaphragm are molded on this and the membrane thereby takes the form of a negative impression of the spectacle lens.

If the upper membrane in the desired manner At the bottom of the lens, the position of the Cylinder pins are fixed. For this purpose, in the housing a Rubber sleeve provided, which surrounds the cylinder pins and can be inflated with pressure. She expands while doing so and locks the outside Straight pins.

There the whole of the cylinder pins package is compressed, can the cylinder pins no longer move relative to each other, so that all pins relative to the housing or spectacle lens are fixed. The support of the spectacle lens takes place then on its entire central surface through the molded upper Membrane.

Of the size Advantage of this variant 3 of the food intake is that the areal support the central areas of the lenses is possible without for each of the many different surface geometries specially shaped support elements required are.

The here provided support device can adapt in succession to any geometry of the lenses. The generated thereby form of a negative impression of the spectacle lens can for the Duration of processing to be fixed. After that, another geometry be generated.

The Collet for clamping the lenses is also preferred driven by compressed air. This is also in the area of the collet a rubber sleeve is present, which is wrapped around the jaws is. When exposed to compressed air, the rubber boot expands and pushes the jaws inward against the lens.

The needed Compressed air for the propulsion and the fixation of the cylindrical pins and the operation of the Collet, is through channels (Holes) in the housing directed to the appropriate places of the receiving diet. If necessary, are for forwarding the air to the points of consumption also short pieces of pipe intended.

It However, there are other versions with flexible support elements provided, such. B. a variant 4, in which the between membranes arranged cylindrical pins are replaced by a suspension, which solidifies under the influence of magnetic fields. Such Suspensions are known from other fields of technology and exist z. From an oil, in which fine iron powder is suspended.

Also so it is possible to shape the geometry of the spectacle lens. This is the lower membrane pressurized with compressed air, this pressure being from the suspension transferred to the upper membrane and pushes it to the bottom of the lens. Subsequently finds a fixation of this form by switching on an electromagnet instead of. Also lets that go support the lens flatly.

The device according to the invention will be described below with reference to three examples and the 1 to 3 explained in more detail. It is, however also other versions provided.

1 shows the device according to the invention with cylindrical support element

2 shows the device with a cylindrical pin as a support element (variant 2)

3 shows the device with flexible support device (variant 3)

To 1

In this figure, the feed ( 25 ) with cylindrical support element ( 32 ) according to variant 1, which is suitable for rotationally symmetrical lenses or spectacle lenses.

The feed ( 25 ) has as its outer supporting structure a lower housing part ( 1 ) and an upper housing part ( 9 ), which by means of a screw connection ( 12 ) are interconnected.

In the center of the housing lower part ( 1 ) and the upper housing part ( 9 ) is the cylindrical support element ( 32 ) in holes in the upper housing part ( 9 ) and the intermediate ring ( 8th ) is guided axially displaceable. The cylindrical support element ( 32 ) settles from below with its annular support edge ( 35 ) to the spectacle lens ( 11 ) and supports this. The support takes place along a circular ring.

The intermediate ring ( 8th ) is from the upper housing part ( 9 ) by means of the screw connection ( 12 ) against the lower membrane ( 4 ) and hold it on the heel ( 14 ) of the lower housing part ( 1 ) tightly sealed. The lower membrane ( 4 ) lays down from below to the cylindrical support element ( 32 ) and displaces this axially when its underside is pressurized with compressed air.

The cylindrical support element ( 32 ) is replaced by a rubber cuff ( 15 ) spanned in an inner recess ( 16 ) of the intermediate ring ( 8th ) is housed. The rubber cuff ( 15 ) can be acted upon with compressed air, wherein it expands. As a result, it presses against the cylindrical support element ( 32 ), whereby this is locked.

The supporting device ( 2 ) is thus formed by the cylindrical support element ( 32 ), the lower membrane ( 4 ), the rubber boot ( 15 ) and the intermediate ring ( 8th ).

To supply the lower membrane ( 4 ) with compressed air serves a central bore ( 17 ) with a cylindrical extension ( 18 ) in the housing lower part ( 1 ). This cylindrical extension ( 18 ) is directed upwards from the lower membrane ( 4 ) limited.

The rubber cuff ( 15 ) is designed as a one-sided open hollow part, so that its interior through the holes ( 19 ) and ( 20 ) can be acted upon with compressed air. Because the rubber cuff ( 15 ) up, down and out from the walls of the recess ( 16 ) of the intermediate ring ( 8th ) is supported, it can expand under the action of compressed air in the desired manner only inwards and so the function of a locking device for the cylindrical support element ( 32 ) take.

Above is at the housing lower part ( 1 ) the upper housing part ( 9 ) by means of the screw connection ( 12 ) flanged and carries in a recess radially displaceable jaws ( 21 ) of the collet ( 22 ).

To these jaws ( 21 ) is also a rubber boot ( 23 ), which are located in a recess ( 24 ) of the upper housing part ( 9 ) and, like the rubber boot ( 15 ) is designed as an open hollow part and can be acted upon with compressed air. It expands inwards and pushes the jaws ( 21 ) against the spectacle lens ( 11 ), whereby this in the collet ( 22 ) of the receiving feed ( 25 ) is tightened.

For applying the rubber cuff ( 23 ) with compressed air serve two bore ( 26 ) and ( 27 ) in the housing lower part ( 1 ). To the hole ( 27 ) includes a double-angled tube ( 28 ) that connects to a hole ( 29 ) in the upper housing part ( 9 ). This hole ( 29 ) opens in the recess ( 24 ), whereby the rubber cuff ( 23 ) can be supplied with compressed air.

In the lower area, the lower housing part ( 1 ) via a flange ( 30 ) of the holes ( 31 ) has a screw connection. By means of the flange ( 30 ), the feed ( 25 ) are attached to the spindles (not shown) of the various processing machines. These spindles have rotary unions and air ducts for the compressed air, the latter being arranged to be flush with the holes (FIG. 17 ) 20 ) and ( 26 ) when the feed ( 25 ) is mounted on the relevant spindle.

The functionality is as follows:
The spectacle lens ( 11 ) is inserted into the opened collet ( 22 ) (rubber sleeve ( 23 ) not pressurized with compressed air). In the case of convex-shaped spectacle lenses ( 11 ) whose underside may already be at the annular support edge ( 35 ) of the cylindrical support element ( 32 ) and push this down a bit. For concave-shaped lenses ( 11 ) finds such a touch when inserting into the collet ( 22 ) usually does not take place.

After inserting the spectacle lens ( 11 ) the rubber cuff ( 23 ) is pressurized with compressed air, whereby the clamping jaws ( 21 ) inwardly against the spectacle lens ( 11 ) and tighten this.

Then the lower membrane ( 4 ) over the hole ( 17 ) and the cylindrical extension ( 18 ) is pressurized with compressed air and presses the cylindrical support element ( 32 ) with its annular support edge ( 35 ) to the underside of the spectacle lens ( 11 ). This pressing takes place in accordance with the set air pressure with a defined force, so that it does not lead to unwanted bending of the spectacle lens ( 11 ) comes.

About the holes ( 20 ) and ( 19 ) then the rubber boot ( 15 ) is pressurized with compressed air, whereby it expands and the cylindrical support element ( 32 ) in its position. This is the lens ( 11 ) is annularly supported in its central area.

To 2

In this figure, the feed ( 25 ) with the cylindrical pin ( 33 ) shown as a support element (variant 2).

Variant 2 of the feed ( 25 ) corresponds in its basic structure of the execution accordingly 1 , Estimating the spectacle lens ( 11 ) takes place here not annular but punctiform.

In the center of the housing lower part ( 1 ) and the upper housing part ( 9 ) is the support element, which in this case from a cylindrical pin ( 33 ) attached to a piston ( 34 ) is attached. The piston ( 34 ) is in holes in the housing upper part ( 9 ) and the intermediate ring ( 8th ) guided axially displaceable. The cylinder pin ( 33 ) lies down on the spectacle lens ( 11 ) and supports this.

The intermediate ring ( 8th ) is again from the upper housing part ( 9 ) by means of the screw connection ( 12 ) against the lower membrane ( 4 ) and hold it on the heel ( 14 ) of the lower housing part ( 1 ) tightly sealed. The lower membrane ( 4 ) lays down from below on the piston ( 34 ) and moves it axially upward when its underside is pressurized with compressed air.

The piston ( 34 ) is replaced by a rubber cuff ( 15 ) spanned in an inner recess ( 16 ) of the intermediate ring ( 8th ) is housed. The rubber cuff ( 15 ) can be acted upon with compressed air, wherein it expands. As a result, it presses against the piston ( 34 ), whereby this is locked.

The supporting device ( 2 ) is thus formed by the cylinder pin ( 33 ), the piston ( 34 ), the lower membrane ( 4 ), the rubber boot ( 15 ) and the intermediate ring ( 8th ).

The supply of the lower membrane ( 4 ) and the rubber sleeve ( 15 ) with compressed air is again provided as at 1 already described. The same applies to the arrangement and structure of the collet ( 22 ) and the attachment of the receiving food ( 25 ) on the spindles of the processing machines.

The mode of operation corresponds to that, as already described in connection with variant 1, except that here the cylindrical pin ( 33 ) punctiform from below to the spectacle lens ( 11 ) applies.

To 3

In this figure, the feed ( 25 ) with flexible support device (variant 3), which the spectacle lens ( 11 ) supported flat in the center.

Shown is the feed ( 25 ) with a plurality of axially displaceable cylindrical pins ( 5 ), which at its upper end by an upper membrane ( 3 ) are covered. The upper membrane ( 3 ) can with the spectacle lens ( 11 ). If their then assumed position is fixed, results in a nearly flat support of the spectacle lens ( 11 ). The between the cylinder pins ( 5 ) and the spectacle lens ( 11 ) arranged upper membrane ( 3 ) made of rubber or similar material further improves the uniformity of the support.

Also in this variant 3, the feed ( 25 ) as main components via a housing lower part ( 1 ) and an upper housing part ( 9 ), which by means of a screw connection ( 12 ) are interconnected.

In the center of the housing lower part ( 1 ) and the upper housing part ( 9 ) is the support device ( 2 ), which interfere with the upper membrane ( 3 ) to the spectacle lens ( 11 ) from below and supports this.

In the example shown, the upper membrane ( 3 ) a hollow cylinder ( 6 ), which is firmly connected to it and consists of the same material. In its lower part has the hollow cylinder ( 6 ) via an annular flange ( 7 ).

The upper membrane ( 3 ), the hollow cylinder ( 6 ) and the annular flange ( 7 ) form a coherent rubber molding ( 10 ) manufactured as a unit of uniform material (eg, rubber). The annular flange ( 7 ) is used to fix this rubber molding ( 10 ) in the housing lower part ( 1 ). The annular flange ( 7 ) is there by the intermediate ring ( 8th ) tightened.

The intermediate ring ( 8th ) is thereby from the upper housing part ( 9 ) by means of the screw connection ( 12 ) against the annular flange ( 7 ), which presses this contact force against an intermediate washer ( 13 ), which in turn conveys the lower membrane ( 4 ) sealing against a shoulder ( 14 ) of the lower housing part ( 1 ) presses.

The cylindrical pins ( 5 ) are located inside the downwardly open rubber molded part ( 10 ). This opening is from the lower membrane ( 4 ), there the cylinder pins ( 5 ) is supported.

The hollow cylinder ( 6 ) and thus also the cylindrical pins ( 5 ), are replaced by a rubber cuff ( 15 ) spanned in an inner recess ( 16 ) of the intermediate ring ( 8th ) is housed. The rubber cuff ( 15 ) can be acted upon with compressed air, wherein it expands. Thereby she presses the hollow cylinder ( 6 ) and the cylindrical pins ( 5 ) together, whereby these are locked.

To supply the lower membrane ( 4 ) with compressed air serves a central bore ( 17 ) with a cylindrical extension ( 18 ) in the housing lower part ( 1 ). This cylindrical extension ( 18 ) is directed upwards from the lower membrane ( 4 ) with their outer area on the heel ( 14 ) and seals against it.

The rubber cuff ( 15 ) is designed as a one-sided open hollow part, so that its interior via the bore ( 19 ) and the bore ( 20 ) can be acted upon with compressed air. Because the rubber cuff ( 15 ) up, down and out from the walls of the recess ( 16 ) of the intermediate ring ( 8th ) is supported, it can expand under the action of compressed air in the desired manner only to the inside and thus take over the function of a locking device.

Above is at the housing lower part ( 1 ) the upper housing part ( 9 ) by means of the screw connection ( 12 ) flanged and carries in a recess radially displaceable jaws ( 21 ) of the collet ( 22 ).

To these jaws ( 21 ) is also a rubber boot ( 23 ), which are located in a recess ( 24 ) of the upper housing part ( 9 ) and, like the rubber boot ( 15 ) is designed as an open hollow part and can be acted upon with compressed air. It expands inwards and pushes the jaws ( 21 ) against the spectacle lens ( 11 ), whereby this in the feed ( 25 ) is tightened.

For applying the rubber cuff ( 23 ) with compressed air serve two bore ( 26 ) and ( 27 ) in the housing lower part ( 1 ). To the hole ( 27 ) includes a double-angled tube ( 28 ) that connects to a hole ( 29 ) in the upper housing part ( 9 ). This hole ( 29 ) opens in the recess ( 24 ), whereby the rubber cuff ( 23 ) can be supplied with compressed air.

In the lower area, the lower housing part ( 1 ) via a flange ( 30 ), the holes ( 31 ) has a screw connection. By means of the flange ( 30 ), the feed ( 25 ) are attached to the spindles (not shown) of the various processing machines. These spindles have rotary unions and air ducts for the compressed air, the latter being arranged to be flush with the holes (FIG. 17 ) 20 ) and ( 26 ) when the feed ( 25 ) is mounted on the relevant spindle.

The functionality is as follows:
The spectacle lens ( 11 ) is inserted into the opened collet ( 22 ) (rubber sleeve ( 23 ) not pressurized with compressed air). In the case of convex-shaped spectacle lenses ( 11 ) whose underside may already be on the upper membrane ( 3 ) and pushes them together with the cylindrical pins ( 5 ) something down. For concave-shaped lenses ( 11 ) finds such a touch when inserting into the collet ( 22 ) usually does not take place.

After inserting the spectacle lens ( 11 ) the rubber cuff ( 23 ) is pressurized with compressed air, whereby the clamping jaws ( 21 ) inwardly against the spectacle lens ( 11 ) and tighten this.

Then the lower membrane ( 4 ) over the hole ( 17 ) and the cylindrical extension ( 18 ) is pressurized with compressed air and presses the cylindrical pins ( 5 ) up. There they hit against the upper membrane ( 3 ) and push them to the bottom of the lens ( 11 ). This pressing takes place in accordance with the set air pressure with a defined force, so that it does not lead to unwanted bending of the spectacle lens ( 11 ) comes.

About the holes ( 20 ) and ( 19 ) then the rubber boot ( 15 ) with compressed air beats, causing it to expand while holding the hollow cylinder ( 6 ) against the cylindrical pins ( 5 ) presses. By this compression the cylindrical pins ( 5 ) tightened in their position. Thus the spectacle lens ( 11 ) from the upper membrane ( 3 ) or the cylindrical pins ( 5 ) supported flat in its central area.

The variant 4 is not shown further, since it substantially corresponds to variant 3, wherein only the cylindrical pins ( 5 ) are replaced by the suspension and instead of the intermediate ring ( 8th ) a solenoid is present. The rubber cuff ( 15 ) can be omitted in this embodiment.

1

Housing bottom

2

support device

3

upper membrane

4

lower membrane

5

straight pins

6

hollow cylinder

7

annular flange

8th

intermediate ring

9

Housing top

10

Rubber molding

11

lens

12

screw connection

13

shim

14

paragraph

15

rubber sleeve

16

recess

17

drilling

18

cylindrical extension

19

drilling

20

drilling

21

jaws

22

collet

23

rubber sleeve

24

recess

25

recording feed

26

drilling

27

drilling

28

doubly angled pipe

29

drilling

30

flange

31

drilling

32

cylindrical support element

33

straight pin

34

piston

35

annular support edge

Claims (13)

Device for holding spectacle lenses and other shaped bodies which are provided with optically effective surfaces during machining, having a housing ( 1 . 9 ), which has a holder ( 22 ) for a workpiece to be machined ( 11 ), wherein between an upper housing part ( 9 ) and a screwed with him housing part ( 1 ) an intermediate ring ( 8th ) is present, on the axially movable support body ( 32 ; 34 ; 10 ) by means of a radially acting rubber sleeve ( 15 ) are pneumatically actuated fixed, characterized in that • the intermediate ring ( 8th ) together with a membrane ( 4 ) between the housing lower part ( 1 ) and the upper housing part ( 9 ) is axially clamped, • that in the intermediate ring ( 8th ) on the membrane ( 4 ) seated cylindrical support body ( 2 ; 34 ; 10 ) is axially movable, • that in the upper housing part ( 9 ) a radially acting rubber sleeve ( 23 ) for air-operated fixing of the holder ( 22 ), and • that compressed air channels ( 17 ; 20 ; 26 ... 29 ) from the lower housing part ( 1 ) into a cavity ( 18 ) under the membrane ( 4 ) and in the rubber sleeves ( 15 ; 23 ) to lead. Device according to claim 1, characterized in that the rubber sleeves ( 15 ; 23 ) each in a radial groove-like recess ( 16 ; 24 ) are fitted. Apparatus according to claim 1 or 2, characterized in that the cavity from one to an axial compressed air duct ( 17 ) subsequent cylindrical extension ( 18 ) is formed. Device according to one of claims 1 to 3, characterized in that the supporting body ( 32 ; 34 ; 10 ) the workpiece ( 11 ) annular, punctiform or flat supports. Device according to one of claims 1 to 4, characterized in that the supporting body a cylindrical support element ( 32 ; 34 ), the bracket side an annular support edge ( 35 ) or an axially arranged cylindrical pin ( 33 ) having. Device according to one of claims 1 to 4, characterized in that the supporting body is a cylindrical rubber molded part ( 10 ) with an upper concave membrane ( 3 ). Apparatus according to claim 6, characterized in that the rubber molded part ( 10 ) a number of axially parallel and mutually displaceably arranged cylindrical pins ( 5 ) in a hollow cylinder ( 6 ). Apparatus according to claim 6 or 7, characterized in that the rubber molded part ( 10 ) at its lower end an annular flange ( 7 ), which together with an intermediate washer ( 13 ) and the membrane ( 4 ) between the housing lower part ( 1 ) and the upper housing part ( 9 ) is axially clamped. Device according to one of claims 3 to 8, characterized in that in the lower housing part ( 1 ) three compressed air channels ( 17 ; 20 ; 26 ) are arranged axially parallel, preferably in a plane. Apparatus according to claim 9, characterized in that an outer compressed air duct ( 20 ) via a radial transverse channel ( 19 ) with the rubber sleeve of the intermediate ring ( 8th ) and a second outer compressed air duct ( 27 ) via a radial transverse channel ( 27 ), a double-angled tube ( 28 ) and a third radial transverse channel ( 29 ) with the rubber sleeve ( 23 ) in the upper housing part ( 9 ) are fluidly connected. Device according to one of claims 1 to 10, characterized in that the rubber sleeve ( 23 ) in the upper housing part ( 9 ) the jaws ( 21 ) a collet ( 22 ) encloses. Device according to one of claims 1 to 11, characterized in that the lower housing part ( 1 ) on the bottom side a radially projecting flange ( 30 ) having axially parallel arranged bores for receiving fastening screws. Apparatus according to claim 6 or 8, characterized in that the rubber molded part ( 10 ) contains a magnetizable suspension and that instead of the intermediate ring ( 8th ) and the associated rubber sleeve ( 15 ) a solenoid is present.