Patent Description:
An apparatus for polishing lenses for eyeglass lenses is known from <CIT> and <CIT>. The apparatus is characterized by an automation of the lens change and tool change. The lenses to be polished or processed are automatically transported into the apparatus, while the finished processed lenses are automatically transported out of the apparatus. Depending on the processing task, different polishing tools are kept in magazines so that also lenses with extreme geometries, e.g. a high diopter value, can be polished. Here, a necessary tool change, depending on the processing task, is also carried out automatically.

<CIT> discloses a polishing machine for the fine machining of optically active surfaces on, in particular, spectacle lenses. The polishing machine comprises two workpiece spindles and two tool spindles. The polishing machine comprises a linear drive unit by which a tool carriage with the tool spindles can be moved linearly. Each of the tool spindles comprises its own electric rotary drive.

<CIT> relates to a lens machining machine. The machining machine comprises a swivel apparatus with two workpiece spindles. By means of the swivel apparatus, the workpiece spindles can be swiveled by <NUM>° to a polishing station having two polishing units.

<CIT> relates to a high performance cutting and turning machine and method for machining particularly spectacle lenses. The machine comprises a cutting unit with a single cutter spindle unit for cutting machining a lens in a pre-machining operation. Further, a turning unit is provided which comprises two so called fast tool arrangements for turning machining the lens in a post-machining operation.

<CIT> relates to a device for fine processing of optically effective surfaces on, in particular, eyeglass lenses. The device has one workpiece spindle and two tool spindles. The tool spindles are drivable at a given time independently of one another for rotation about their tool axes. If different polishing tools are used at the two tool spindles of the device, it is possible to carry out preparatory polishing and fine polishing. Multiple identical devices can be arranged in a common machine frame as polishing cells.

The object of the present invention is to further simplify an apparatus for processing optical workpieces while providing a broader range of applications.

The above object is solved by an apparatus according to claim <NUM> or by a method according to claim <NUM>. Advantageous further developments result from the subclaims.

In the apparatus, at least two pairs of tool spindles are provided, that at least one device for rotational drive and, preferably, two devices for rotational drive, are provided for the at least two pairs of tool spindles, and that at least one device for linear drive and, preferably, two devices for linear drive, are provided for the at least two pairs of tool spindles along their center axes.

This proposed construction allows the apparatus to be used much more flexibly and/or in a wider range of applications.

According to the method claim, a two-stage processing method is implemented on optical workpieces received on workpiece spindles being able to be processed first by means of processing tools located on a first pair of tool spindles. Subsequently, the optical workpieces are processed by means of processing tools located on a second or further pair of tool spindles. Particularly advantageously, the same or different processing tools can be used for each pair of tool spindles.

Preferably, the proposed apparatus is further characterized in that the device for linear drive comprises a slide on which the pair of tool spindles is mounted, and in that the slide is arranged on a linear guide so as to be linearly movable along the center axes of the pair of tool spindles.

The proposed apparatus has a substantially simplified construction compared to the prior art, since now the pair of tool spindles is fixed on its slide provided for this purpose and the infeed or movement of the pair of tool spindles in the direction of the workpiece spindles or the optical workpieces received thereon (i.e. in the direction of the Z-axis of the apparatus) is effected only via the movement of the slide provided.

In other words, the respective Z axes are outsourced from or removed from or moved out of the pair of tool spindles.

The development of the proposed apparatuses was carried out with regard to the fact that, contrary to the state of the art cited above, both a tool magazine and an automated apparatus for tool change became dispensable.

A further consequence is that now the change of the processing tools in case of wear or damage is not only possible manually, but especially preferably always carried out manually.

In the method, it is provided that for processing the optical workpieces a pre-processing step is carried out with a first pair of tool spindles with first processing tools mounted thereon and that immediately thereafter, i.e. without interrupting the process, in particular without changing tools, a post-processing step is carried out with a second pair of tool spindles with second processing tools mounted thereon.

In a particularly preferred embodiment, at least two pairs of tool spindles are provided, wherein each device for linear drive has at least two slides, on each of which a pair of tool spindles is mounted, and wherein each slide is arranged on a linear guide so as to be linearly movable along the center axes of the respective pair of tool spindles. In this preferred further development, the respective Z axes are also removed from or outsourced from or moved out of the pairs of tool spindles.

A further particularly preferred construction of the apparatus is that a handling device for handling the optical workpieces is provided outside the working space on a first side of the working space and that the at least one device for linear drive is arranged on a second side of the working space facing away from the first side of the working space.

The at least one device for linear drive is thus arranged on the edge side within the apparatus, i.e. after removal of the corresponding part of the casing of the apparatus, the at least one apparatus for linear drive is freely accessible, in particular for maintenance and repair purposes.

It is also conceivable to combine two pairs of tool spindles with two pairs of workpiece spindles in an appropriately dimensioned apparatus, so that four optical workpieces can be processed simultaneously in one processing step.

In a preferred embodiment, a device for rotational drive of the tool spindles can be realized in that, respectively, a pair of tool spindles can be driven synchronously in rotation.

A preferred device for linear drive of a pair of tool spindles has a toothed rack fixed to the respective slide, which meshes with a rotationally drivable gear wheel or toothed wheel. This ensures that each pair of tool spindles can be synchronously driven linearly.

A particularly preferred embodiment of the present invention provides that each device for linear drive is arranged on at least one base plate. Particularly preferably, a base plate is provided, on the upper side of which a first device for linear drive and on the lower side of which a second device for linear drive are provided.

In particular, the second device for linear drive can be arranged essentially mirrored to the first device for linear drive, wherein the common base plate forms the mirror plane.

This particularly preferred form of modular construction of the two devices for linear drive makes it possible in a particularly simple manner to manufacture apparatuses with, in particular, one pair or two pairs of tool spindles according to customer's requirements.

The preferred modular structure described above allows in particular that preferably one pair of tool spindles or two pairs of tool spindles can be provided. This makes it possible, depending on the customer's requirements, to provide apparatuses in which the actual processing of the optical workpieces is carried out in one stage, i.e. in one processing step (with one pair of tool spindles) or in two stages, i.e. in two processing steps (with two pairs of tool spindles, each pair being equipped with different processing tools).

A further preferred further development of the apparatus is that a tool holder is attached or fixed to each tool spindle, on which tool holder a processing tool is rigidly received or rigidly held.

The aforementioned aspects and features as well as the aspects and features of the present invention resulting from the claims and the following description can in principle be realized independently of each other, but also in any combination.

An exemplary embodiment of the present invention is described in more detail below with reference to the accompanying drawings. It shows in schematic, not to scale representation:.

In the figures, some of which are not to scale and are merely schematic, the same reference signs are used for the same, similar or alike parts and components, wherein corresponding or comparable properties and advantages are achieved, even if a repeated description is omitted.

<FIG> shows an exemplary embodiment of an apparatus <NUM> according to the invention in a perspective view. The apparatus <NUM> is used for processing optical workpieces <NUM>, in particular optical surfaces of workpieces <NUM> such as, for example, optical surfaces of lenses, in particular spectacle lenses.

The apparatus <NUM> has a casing <NUM> which encloses a plurality of work stations as well as peripheral devices (see below). A part <NUM> of the casing <NUM> covers a conveyor device <NUM>, in the exemplary embodiment a conveyor belt, so that the apparatus <NUM> can be integrated into a system for processing optical workpieces <NUM> with a plurality of separate processing devices, such as is known, for example, from <CIT>.

In the exemplary embodiment, the apparatus <NUM> is CNC-controlled, so that a control panel <NUM> is provided with which an operator can control and monitor the functions of the apparatus <NUM> and/or the processing sequences when processing the optical workpieces <NUM>.

<FIG> shows an interior view of the apparatus <NUM> according to <FIG>. The casing <NUM> encloses a working chamber <NUM>, a cleaning station <NUM> and/or a handling device <NUM> for handling the optical workpieces <NUM> to be processed.

A device for tool inspection <NUM> is used for sensory inspection of the processing tools <NUM> used in the apparatus <NUM> (see below).

A working chamber <NUM> for use in the apparatus <NUM> is shown in a perspective view in <FIG>.

The working chamber <NUM> has a chamber housing <NUM> which encloses a working space <NUM>.

The chamber housing <NUM> can be opened and closed by means of a movable cover as described, for example, in <CIT> (not shown).

Two workpiece spindles <NUM>, <NUM>', known per se, are arranged within the working space <NUM>. The workpiece spindles <NUM>, <NUM>' are accommodated on a common spindle housing <NUM>.

The distance between the center axes Mws of the workpiece spindles <NUM>, <NUM>' running parallel to the X axis of the apparatus <NUM> is <NUM> in the example; this corresponds to the preset distance between the center axes MW of the optical workpieces <NUM> to be processed.

The X axis, Y axis and Z axis of the apparatus <NUM> are shown in <FIG>. The terms "X direction", "Y direction" and "Z direction" preferably refer to these axes.

The X axis, Y axis and Z axis preferably form an orthogonal basis or are mutually orthogonal.

Preferably, the X direction is the vertical direction and the Y and Z direction are the respective horizontal directions, in particular orthogonal or perpendicular to each other.

The workpiece spindles <NUM>, <NUM>' are arranged rotatably about a rotation axis Rws, wherein in the exemplary embodiment the rotation axis Rws coincides with the respective center axis Mws of the workpiece spindles <NUM>, <NUM>'. Drive devices known per se for this rotation of the workpiece spindles <NUM>, <NUM>' are accommodated in the spindle housing <NUM>.

In the exemplary embodiment, the spindle housing <NUM> and thus the workpiece spindles <NUM>, <NUM>' are designed to be pivotable about the B-axis of the apparatus <NUM> by means of a swivel drive <NUM>.

In the exemplary embodiment, the swivel drive <NUM> has a motor <NUM> with a shaft gear (hereinafter: gear motor <NUM>) with a hollow shaft for the cable feed-through (not shown), known per se, the motor <NUM> being accommodated in a B-axis housing <NUM> for protection against contamination.

A B-axis flange <NUM> is attached to the B-axis housing <NUM>, which is operatively connected on the one hand to the gear motor <NUM> and on the other hand to the spindle housing <NUM>.

The entire structural unit with the workpiece spindles <NUM>, <NUM>', the spindle housing <NUM> and the B-axis housing <NUM> together with the gear motor <NUM> and B-axis flange <NUM> is further designed to be movable along the X-axis of the apparatus <NUM>. On the one hand, this has the effect that the workpiece spindles <NUM>, <NUM>' can be loaded with optical workpieces <NUM> (see below). On the other hand, the infeed or movement of the optical workpieces <NUM> to the processing tools <NUM> can be optimized (see below).

In a manner known per se, an X-axis motor <NUM> drives, via a ball screw, a base plate to which the B-axis housing <NUM> is connected via a cylinder and a cantilevered plate (not shown).

In the illustrated embodiment, two pairs of tool spindles <NUM>, <NUM>' and <NUM>, <NUM>', respectively, are accommodated within the working space <NUM>.

The first, in X-direction upper pair of spindles <NUM>, <NUM>' is used for a first processing step, while the second, in X-direction lower pair of spindles <NUM>, <NUM>' is used for a second processing step. The optical workpieces <NUM> are thus processed in a two-stage processing method.

However, in another embodiment, which is not covered by the claims, it is also possible to provide only one pair of tool spindles <NUM>, <NUM>' or <NUM>, <NUM>', preferably the upper pair of tool spindles <NUM>, <NUM>' in the direction of the X axis of the apparatus <NUM>. In this case, the optical workpieces may be processed in a single-stage processing method.

Furthermore, it is also possible, for example, to equip two pairs of tool spindles <NUM>, <NUM>'; <NUM>, <NUM>' with identical processing tools <NUM> and to process the optical workpieces <NUM> in a single-stage processing method. In this case, the tool change interval is doubled, i.e. four instead of two processing tools <NUM> have to be replaced after the doubled service life, whereby an interruption of the processing of the optical workpieces <NUM> is required only once per work shift of the respective operator, for example.

It is also possible to enlarge the working space <NUM> of the working chamber <NUM> in such a way that two pairs of workpiece spindles are arranged on a correspondingly enlarged spindle housing, to which two pairs of tool spindles <NUM>, <NUM>'; <NUM>, <NUM>' are assigned. In this case, four optical workpieces <NUM> can be processed simultaneously in a single-stage processing method.

For each pair of tool spindles <NUM>, <NUM>' and/or <NUM>, <NUM>' a device <NUM>, <NUM>' for rotational drive of the respective pair of tool spindles <NUM>, <NUM>' and/or <NUM>, <NUM>' as well as a device <NUM>, <NUM>' for linear drive of the respective pair of tool spindles <NUM>, <NUM>' and/or <NUM>, <NUM>' along the Z-axis of the apparatus <NUM> and/or along center axes Mwz of the respective tool spindles <NUM>, <NUM>' and/or <NUM>, <NUM>' arranged parallel thereto are provided.

As can be seen from <FIG>, each tool spindle <NUM>,<NUM>'; <NUM>, <NUM>' passes through the chamber housing <NUM> of the working chamber <NUM> to the outside.

Outside the working chamber <NUM>, a base plate <NUM> is provided with an upper side 32a and a lower side 32b.

The base plate <NUM> is fixed in a manner known per se to a base frame of the apparatus <NUM> (not shown).

On the upper side 32a of the base plate <NUM>, the respective devices <NUM>, <NUM> for rotational and/or linear drive for the upper pair of tool spindles <NUM>, <NUM>' are provided.

On the lower side 32b of the base plate <NUM>, the respective devices <NUM>', <NUM>' for rotational and/or linear drive for the lower pair of tool spindles <NUM>, <NUM>' are provided.

The respective devices <NUM>, <NUM>', <NUM>, <NUM>' are arranged substantially mirrored to each other along the base plate <NUM> as a mirror plane.

A pair of guide rails <NUM>, <NUM>'; <NUM>, <NUM>', is mounted on both the upper side 32a and the lower side 32b of the base plate <NUM>.

On the upper pair of guide rails <NUM>, <NUM>' an upper slide <NUM> of substantially trough-shaped cross-section is provided, while on the lower pair <NUM>, <NUM>' of guide rails a lower slide <NUM> of substantially trough-shaped cross-section is provided.

Both slides <NUM>, <NUM> are arranged on the respective pair of guide rails <NUM>, <NUM>' or <NUM>, <NUM>' so as to be movable in the Z direction of the apparatus <NUM>. For this purpose, upper or lower guide carriages <NUM>, <NUM>'; <NUM>, <NUM>', in the exemplary embodiment guide carriages mounted on rolling bearings, are arranged in a manner known per se between the respective slides <NUM>, <NUM> and the respective associated guide rails <NUM>, <NUM>' or <NUM>, <NUM>'.

A holder <NUM>, <NUM>' with a toothed rack <NUM>, <NUM>' fixed thereto is provided on each slide <NUM>, <NUM>. Each toothed rack <NUM>, <NUM>' meshes with a corresponding toothed wheel <NUM>, <NUM>'. Each toothed wheel <NUM>, <NUM>' is rotationally connected to a motor <NUM>, <NUM>' known per se.

This structure has the effect that, in the exemplary embodiment, each pair of tool spindles <NUM>, <NUM>' and/or <NUM>, <NUM>' is arranged so as to be synchronously movable along the Z-axis of the apparatus <NUM>.

Furthermore, the mirror-symmetrical construction due to the base plate <NUM> serving as a mirror plane allows to provide only the upper pair of tool spindles <NUM>, <NUM>' or all two pairs of tool spindles <NUM>, <NUM>' and <NUM>, <NUM>', depending on the customer's requirements, without having to extensively rebuild the apparatus <NUM>.

The preferred modular structure of the apparatus <NUM> is further accompanied, as can be seen from <FIG>, by a corresponding arrangement of X, Y and Z axes and the B axis of the apparatus <NUM>.

As described above, the spindle housing <NUM> with the workpiece spindles <NUM>, <NUM>' received thereon is linearly movable along the X-axis of the apparatus <NUM> as well as pivotable about the B-axis of the apparatus <NUM>. The pair or the at least two pairs of tool spindles <NUM>, <NUM>'; <NUM>, <NUM>' are linearly movable along the Z-axis of the apparatus <NUM>.

The described arrangement of the axes with respect to each other allows that, for example, in the exemplary embodiment the pair of tool spindles <NUM>, <NUM>' can serve a pre-polishing of the optical workpieces <NUM>, while the pair of tool spindles <NUM>, <NUM>' can serve a post-polishing of the optical workpieces <NUM>. This requires that the tool spindles <NUM>, <NUM>'; <NUM>, <NUM>' and/or the processing tools <NUM> received thereon can be adequately advanced/fed or moved in the direction of the workpiece spindles <NUM>, <NUM>' and/or the optical workpieces <NUM> received thereon.

Therefore, the linear movement of the spindle housing <NUM> along the X-axis and the pivoting movement of the spindle housing <NUM> about the B-axis are selected such that the optical workpieces <NUM> can be brought into a position optimized for the infeed or advancing movement of the tool spindles <NUM>, <NUM>'; <NUM>, <NUM>'. At the same time, the X-axis lift and/or the B-axis swivel are minimized, so that the apparatus <NUM> has a particularly compact construction.

<FIG> shows the devices <NUM>, <NUM>' for rotational drive of each pair of tool spindles <NUM>, <NUM>'; <NUM>, <NUM>'. Each of these devices <NUM>, <NUM>' has a belt <NUM>, <NUM>', in particular a V-ribbed belt, which revolves around pulleys <NUM>, <NUM>' arranged on the tool spindles <NUM>, <NUM>'; <NUM>, <NUM>' and is driven by a motor <NUM>, <NUM>'. This arrangement ensures that each pair of tool spindles <NUM>, <NUM>' and/or <NUM>, <NUM>' is synchronously driven in rotation.

Similarly, the apparatus <NUM> can be easily equipped with either one pair of tool spindles <NUM>, <NUM>' or two pairs of tool spindles <NUM>, <NUM>'; <NUM>, <NUM>' without the need for extensive reconstructions.

Outside the working chamber <NUM>, preferably in the direction of the Y-axis of the apparatus <NUM> (see also <FIG>), a cleaning station <NUM> is arranged, as shown in <FIG> and <FIG>. However, other arrangements are possible as well. For example, the cleaning station <NUM> may be arranged between the working chamber <NUM> and the conveying device <NUM>.

The cleaning station <NUM> has a housing <NUM> in which a vertically extending partitioning wall <NUM> is provided.

The housing <NUM> further has a cover plate <NUM> with a recess <NUM>, which is closable by means of a lid <NUM> movable via a hydraulic or preferably pneumatic cylinder <NUM>.

Two workpiece spindles <NUM>, <NUM>' are arranged to the left and right of the partitioning wall <NUM> for receiving a pair of finished processed optical workpieces <NUM>. In the exemplary embodiment shown, the optical workpieces <NUM> are finished polished lenses blocked on a block piece <NUM> in a manner known per se.

The partitioning wall <NUM> shall prevent mutual contamination of the optical workpieces <NUM> during the cleaning process.

In <FIG>, the workpiece spindles <NUM>, <NUM>' are shown in their lower position with respect to the X axis of the apparatus <NUM>, i.e., in their cleaning position. The optical workpieces <NUM> to be cleaned should be arranged as far away as possible from the cover plate <NUM> in order to avoid contamination by splash water.

In <FIG>, the workpiece spindles <NUM>, <NUM>' are shown in their upper position with respect to the X axis of the apparatus <NUM>, i.e., in their loading and/or unloading position. In this position, the optical workpieces <NUM> protrude from the recess <NUM> of the cover plate <NUM> so that the workpiece spindles <NUM>, <NUM>' can be loaded with optical workpieces <NUM> to be cleaned and/or cleaned optical workpieces <NUM> can be removed from the workpiece spindles <NUM>, <NUM>' (see below).

<FIG> shows a detailed front view of the interior of the cleaning station <NUM> according to <FIG>. This view shows that the workpiece spindles <NUM>, <NUM>' are rotatable about their respective rotation axis RRWS by means of a motor <NUM> via three pulleys 78a, 78b and a V-ribbed belt <NUM>. Here, only the pulley 78a is driven directly by the motor <NUM>, while the two pulleys 78b, which drive the workpiece spindles <NUM>, <NUM>', are driven passively via the V-ribbed belt <NUM>.

It can further be seen from <FIG>, <FIG> that a base plate <NUM> is provided, wherein the workpiece spindles <NUM>, <NUM>' are arranged on the upper side of the base plate <NUM> in the direction of the X-axis and the pulleys 78b are arranged on the corresponding lower side of the base plate <NUM> and are operatively connected to each other.

In addition, it can be seen from <FIG>, <FIG> that a lifting cylinder <NUM>, which operates pneumatically in the exemplary embodiment, is provided below the base plate <NUM>, which in a manner known per se effects the aforementioned height adjustment of the workpiece spindles <NUM>, <NUM>' along the X axis of the apparatus <NUM>.

Finally, it can be seen from <FIG> that sensors <NUM>, <NUM>' are assigned to the workpiece spindles <NUM>, <NUM>' (e.g. reflection light scanners known per se), which detect loading errors on the workpiece spindles <NUM>, <NUM>'.

Here, one aspect is that the optical workpieces <NUM> are cleaned in a two-stage method. The first stage is a washing process and the second stage is a drying process.

<FIG> shows that only two cleaning fluid nozzles 84a, 84b are provided per workpiece spindle <NUM>, <NUM>' and thus per optical workpiece <NUM>.

The upper cleaning fluid nozzle 84a with respect to the X-axis of the apparatus <NUM> is arranged essentially in the circumferential region and slightly above the optical workpiece <NUM>.

The cleaning fluid jet 85a (usually a water jet) emitted from the upper cleaning fluid nozzle 84a sweeps over and thus cleans the polished optical surface and the peripheral surface of the optical workpiece <NUM>.

The lower cleaning fluid nozzle 84b with respect to the X-axis of the apparatus <NUM> is arranged substantially at the level/height of the transition region between the optical workpiece <NUM> and the block piece <NUM>.

The cleaning fluid jet 85b (usually a water jet) emitted from the lower cleaning fluid nozzle 84b sweeps over and thus cleans the block piece <NUM> as well as the surface of the optical workpiece <NUM> projecting from the block piece <NUM>.

In the exemplary embodiment, the workpiece spindles <NUM>, <NUM>' with the optical workpieces <NUM> rotate at about <NUM> rpm during this cleaning process to ensure thorough cleaning along the entire circumferential surfaces of optical workpieces <NUM> and block pieces <NUM>.

The subsequent drying process initially consists of dry spinning of optical workpieces <NUM> and block pieces <NUM> at a rotation of the workpiece spindles <NUM>, <NUM>' of <NUM> rpm in the exemplary embodiment. Here, the cleaning agent adhering to the optical workpieces <NUM> and block pieces <NUM> is spun away due to the centrifugal force acting on it.

However, a drop of water remains in the center of the polished optical surface of the optical workpieces <NUM>, since the optical surfaces are usually concave and thus no centrifugal force acts in this area. In addition, the cleaning agent accumulated in the rear cavity of the block piece <NUM>, which is known per se, cannot be removed. Instead, residues of cleaning agent remain on the rear inner wall of the block piece <NUM>.

To complete the drying process, two compressed air nozzles 86a, 86b are associated with each workpiece spindle <NUM>, <NUM>' and/or the blocked lens <NUM> received thereon.

The compressed air nozzles 86a are arranged in such a way that a discharged compressed air pulse 87a is directed to the center of the usually concave polished optical surface of the optical workpiece <NUM>, so that the water drop remaining there is removed.

The compressed air nozzles 86b are arranged such that a discharged compressed air pulse 87b is directed to the inner wall of the hollow rear side of the respective block piece <NUM>, so that the inner wall is blown dry from below.

Another aspect is that each optical workpiece <NUM> is received by a collet chuck or collet <NUM> via its block piece <NUM>. A detailed view of the collet <NUM> is shown in <FIG>.

In the exemplary embodiment, the collet <NUM> is formed in one piece, in particular injection molded from a suitable plastic.

The collet <NUM> has a retaining ring <NUM> which is received and fixed in a suitable recess at the free end of the workpiece spindles <NUM>, <NUM>' (not shown).

On the upper side 91a of the retaining ring <NUM> (with respect to the X-axis of the apparatus <NUM>), three gripping elements <NUM> are arranged rotationally symmetrically, i.e. at a distance of <NUM>°, respectively.

The three gripping elements <NUM> are integrally connected to the upper side 91a of the retaining ring <NUM> according to the principle of a flexure bearing or flexure hinge. The three gripping elements <NUM> are further integrally connected to an inner plate <NUM>.

The inner plate <NUM> has a central opening <NUM> for receiving and fixing a lifting rod <NUM> (cf.

<FIG> shows that the lifting rod <NUM> is operatively connected to a lifting piston <NUM>, which is pneumatic in the example. The lifting piston <NUM> is received in a piston plate <NUM>. The piston plate <NUM> is received in a rear recess <NUM>' of the pulley 78a or 78b so as to be displaceable along the X axis of the apparatus <NUM>.

Three pressure springs or compression springs <NUM>, which are rotationally symmetrically spaced from one another, bear on one side against a surface of a first receptacle 98a in the piston plate <NUM> and on the other side against a surface in a receptacle 98b in the pulley 78a or 78b.

In the illustrated relaxed state of the compression springs <NUM>, a force acts on the piston plate <NUM> and thus on the lifting rod <NUM> in the direction of the arrow F1. When compressed air D is applied to the lifting piston <NUM>, for example, a force acting in the opposite direction, in the direction of the arrow F2, is exerted on the piston plate <NUM> and thus on the lifting rod <NUM>.

To load the collet <NUM> according to <FIG>, a force is applied to the lifting piston <NUM> as described in a manner known per se. This force acts via the lifting rod <NUM> in the direction of the arrow BB on the inner plate <NUM> in such a way that the inner plate <NUM> is lifted. As a result, the gripping elements <NUM> are pressed outward in the direction of the arrows C. In this position, the collet <NUM> is open so that it can receive the underside of a block piece <NUM> on which an optical workpiece <NUM> is blocked.

Subsequently, the force is removed so that the lifting piston <NUM> and the lifting rod <NUM> return to their initial position according to <FIG> and the collet <NUM> resumes its closed position in such a way that the gripping elements <NUM> engage in the block piece <NUM>. The block piece <NUM> is then fixed positively or fixed in a form-fit manner to the collet <NUM>.

In a manner known per se, the apparatus <NUM> requires a device <NUM> for tool inspection in order to be able to detect damage or even total loss of a processing tool <NUM>.

A proposed device <NUM> for tool inspection according to <FIG> and <FIG> comprises two laser scanners (not shown). Each laser scanner emits a two-dimensional fanned-out laser beam <NUM>, <NUM>. Here, one upper and one lower processing tool <NUM> are inspected simultaneously.

The laser beam <NUM> is configured to inspect the processing tools <NUM> received on the upper tool spindles <NUM>, <NUM>'. For this purpose, the laser beam <NUM> runs essentially perpendicular to the Y-Z plane of the apparatus <NUM> and is inclined backwards by <NUM>° with respect to the X axis.

The laser beam <NUM> is configured to inspect the processing tools <NUM> received on the lower tool spindles <NUM>, <NUM>'. For this purpose, the laser beam <NUM> runs obliquely to the X axis in such a way that, unobstructed by the upper tool spindles <NUM>, <NUM>' and the processing tools <NUM> received thereon, the processing tools <NUM> received on the lower tool spindles <NUM>, <NUM>' can be inspected. The laser beam <NUM> is also inclined backwards by <NUM>°.

For evaluation of the measurement results, a light section sensor is assigned to each laser beam in a manner known per se.

The laser beams <NUM>, <NUM> are arranged in such a way that they hit the tools to be detected exclusively in a radial orientation (cf. This means that only the peripheral surfaces of the processing tools <NUM> to be inspected are detected by the laser beams, but not their front surfaces. By rotating the tool spindles <NUM>, <NUM>'; <NUM>, <NUM>' and thus rotating the processing tools <NUM> during the measurement, a coverage is obtained over the entire inspected circumferential surface of the processing tools <NUM>.

In the exemplary embodiment, the processing tools <NUM> are polishing tools for optical lenses. Such processing tools <NUM> consist in principle, in a manner known per se, of a base body, an intermediate foam layer and a polishing foil, which usually protrudes from the intermediate foam layer. Accordingly, the laser beams <NUM>, <NUM> cover the circumferential surface of the base body, the circumferential surface of the intermediate foam layer, the circumferential edge of the polishing foil and the rear side of the protruding polishing foil (since the laser beams <NUM>, <NUM> are inclined backwards by <NUM>°).

In this exemplary embodiment, cracks and other damage in the intermediate foam layer as well as cracks and other damage at the peripheral edge of the polishing foil can be detected, as well as the total loss, i.e. tearing off of the processing tool <NUM>. A particular advantage is that the inspection of the processing tools <NUM> can now detect defects in the intermediate foam layer and thus prevent a total loss of the processing tool <NUM>, since the processing tool <NUM> can be changed in good time before the total tear-off of the intermediate foam layer.

It can be seen from <FIG> that the device <NUM> for tool inspection, together with its cabling <NUM>, is fixed to a retaining element <NUM>, which in turn engages with a retaining plate <NUM>.

The retaining plate <NUM> is connected to a carrier element <NUM>, which is overlapped by the retaining element <NUM> and onto which a profile rail or guide rail <NUM> is fixed.

A guide carriage <NUM>, preferably a guide carriage mounted on rolling bearings, is fixed to the underside of the retaining element <NUM>, which guide carriage <NUM> engages in the profile rail <NUM>.

The guide carriage <NUM> is operatively connected to a pneumatic or hydraulic cylinder <NUM> via a connecting element <NUM>'. This allows the device <NUM> to be moved in a sliding manner on the profile rail <NUM> along the Y-axis of the apparatus <NUM>.

In the exemplary embodiment, the travel distance is <NUM>; this corresponds to the distance between the center axes Mwz of the tool spindles <NUM>, <NUM>'; <NUM>, <NUM>'.

Below the carrier element <NUM>, a further profile rail or guide rail <NUM> is fixed to a component <NUM> of the machine frame in a manner known per se. A further guide carriage is also fixed below the carrier element <NUM> (not shown).

The carrier element <NUM> is operatively connected to a pneumatic or hydraulic cylinder <NUM> via a connecting element <NUM>'. Thus, the device <NUM> can be moved together with the carrier element <NUM> on the profile rail <NUM> along the Y-axis of the apparatus <NUM>. In this way, the device <NUM> can be brought into a retracted position in such a way that the working space <NUM> of the working chamber <NUM> is freely accessible, for example, for necessary tool changes and/or maintenance work.

For handling the optical workpieces <NUM>, in particular for transporting them into and out of and/or within the apparatus <NUM>, a handling device <NUM> is provided, as shown in <FIG> and in particular <FIG>. The handling device <NUM> is essentially known from <CIT>, to the disclosure of which reference is made.

As can be seen from <FIG>, a conveyor device <NUM> runs along the apparatus <NUM> for transporting optical workpieces <NUM> and/or conveying containers <NUM>' in which the optical workpieces <NUM> are accommodated. Basically, optical workpieces <NUM> to be processed are fed to the apparatus <NUM> by means of the conveyor device <NUM>, and finished processed optical workpieces <NUM> are conveyed out of the apparatus <NUM> and further conveyed.

The conveyor device <NUM> can be an independent component or an integral component of the apparatus <NUM>.

In the exemplary embodiment, the conveyor device <NUM> is suitable for integrating the apparatus <NUM> into a system for processing optical lenses with a plurality of separate processing devices, such as is known, for example, from <CIT>.

In the exemplary embodiment, the conveyor device <NUM> is designed as a transport belt or belt conveyor.

The handling device <NUM> serves to pick up or receive optical workpieces <NUM> in pairs at the conveyor device <NUM>, preferably from the conveying container <NUM>' assigned to the optical workpieces <NUM>, to feed them to the working space <NUM> of the working chamber <NUM> and to load the workpiece spindles <NUM>, <NUM>'.

The handling device <NUM> further serves to remove finished polished optical workpieces <NUM> from the working space <NUM> of the working chamber <NUM> and/or from the workpiece spindles <NUM>, <NUM>', to transport them to the cleaning station <NUM> and to load the workpiece spindles <NUM>, <NUM>' thereof.

Finally, the handling device <NUM> serves to remove cleaned optical workpieces <NUM> from the cleaning station <NUM> or from its workpiece spindles <NUM>, <NUM>' and to transport them back to the conveyor device <NUM> (and preferably to deposit them in the corresponding conveying container <NUM>').

The illustration in <FIG> shows the handling device <NUM> loading the cleaning station <NUM> and/or removing the cleaned optical workpieces <NUM> from the cleaning station <NUM>.

Conveniently, the handling device <NUM> is arranged between the conveyor device <NUM> and the working chamber <NUM> or the cleaning station <NUM>.

The structure of the handling device <NUM> can be seen in particular in <FIG>. The handling device <NUM> has a substantially U-shaped swivel arm <NUM>, to the cross strut <NUM> of which two holding devices <NUM>, <NUM>' are attached.

The swivel arm <NUM> is mounted by means of a holding arm <NUM> on a swivel axis <NUM>' so as to be pivotable about the Y-axis of the apparatus <NUM>.

The cross strut <NUM> is also mounted on a swivel axis <NUM>' so as to be pivotable about the Y-axis of the apparatus <NUM>.

In the exemplary embodiment, the handling device <NUM> further comprises a swivel drive <NUM> for swiveling the swivel arm <NUM> via a belt drive <NUM>, as indicated in <FIG> and <FIG>. The swiveling of the swivel arm <NUM> is performed by means of the belt drive <NUM> in a manner known per se in such a way that during the swiveling process the holding devices <NUM>, <NUM>' always remain perpendicular or vertical, that is, are always aligned parallel to the X-axis of the apparatus <NUM>.

In a manner known per se, each holding device <NUM>, <NUM>' has on opposite sides a first receiving device or pick-up device <NUM>, in the example in the form of a suction cup, and a second receiving device or pick-up device <NUM>, in the example in the form of a <NUM>-finger gripper.

The first pick-up device <NUM> is always used for handling, at the center, optical workpieces <NUM> still to be processed, while the second pick-up device <NUM> is used for handling, at the edge, optical workpieces <NUM> that have already been polished or polished and cleaned, thus finished processed optical workpieces <NUM>.

The essential difference between the handling device <NUM> and the handling device known from <CIT> is that the handling device <NUM> is designed to be displaceable or movable along the Y-axis or another axis, for example the Z-axis, of the apparatus <NUM>, so that the handling device <NUM> can approach both the working chamber <NUM> and the cleaning station <NUM>.

For this purpose, the handling device <NUM> is accommodated on a slide <NUM>, which is arranged movably in a manner known per se by means of guide carriages <NUM>, in the exemplary embodiment guide carriages mounted on rolling bearings, on guide rails <NUM>.

A motor <NUM> serves expediently as the drive for the movement of the slide <NUM>, e.g. along the Y-axis of the apparatus <NUM>.

The guide rails <NUM> run parallel to the Y-axis of the apparatus <NUM> in the shown embodiment.

It is expedient that the slide <NUM>, the guide carriages <NUM> and the guide rails <NUM> are protected in a manner known per se by means of a bellows (not shown) against contamination by any polishing agent that may have been carried away.

A further difference between the tool spindle known from <CIT> and the proposed pairs of tool spindles <NUM>, <NUM>'; <NUM>, <NUM>' used is the design of a proposed tool holder <NUM> for a suitable proposed processing tool <NUM>.

<FIG> show an exemplary embodiment of a proposed tool holder <NUM>.

The tool holder <NUM>, which is formed integrally or as one piece, consists in the exemplary embodiment of an injection-molded plastic. A suitable plastic is, for example, PA <NUM> GF30 (polyamide made from hexamethylenediamine and adipic acid (nylon) with a glass fiber content of <NUM>% by weight).

The tool holder <NUM> has an annular holder head <NUM> centered on a collar <NUM>.

The diameter of the collar <NUM> is larger than the outer diameter of the holder head <NUM>.

Four retaining lugs or retaining elements <NUM>, each spaced <NUM>° apart, are integrally formed on the resulting annular rim <NUM> and are integrally connected to the outer wall <NUM>' of the holder head <NUM>.

Each retaining lug or retaining element <NUM> has a substantially round retaining lug head or retaining element head 124a.

A substantially cylindrical extension <NUM> joins on the side of the collar <NUM> facing away from the holder head <NUM>, which extension <NUM> merges into an annular holder body <NUM>.

<FIG> and <FIG> show the tool holder <NUM> in an embodiment ready for use in the apparatus <NUM>, with a bellows <NUM>, preferably made of a vulcanized rubber and, a spindle flange <NUM>.

A first free end <NUM>' of a conventional bellows <NUM> is vulcanized onto the cylindrical extension <NUM> in a manner known per se. The second free end <NUM>" of the bellows <NUM> is fixed to a collar <NUM> of the spindle flange <NUM> by means of a clip or clamp <NUM>.

When the second free end <NUM>" is pulled onto the collar <NUM>, the material of the bellows <NUM> is stretched so that the second free end <NUM>" of the bellows <NUM> is firmly seated on the collar <NUM>. The clamp <NUM> serves as an additional securing means of the resulting force-fit connection.

In <FIG>, it can be seen that an inner circumferential bead 127a is formed on the second free end <NUM>" of the bellows <NUM> and that the bead 127a engages in an annular circumferential indentation <NUM> behind the collar <NUM>, resulting in an additional form fit between the bellows <NUM> and the spindle flange <NUM>.

<FIG> also shows that an internal disk <NUM> is held clamped in the holder body <NUM> of the tool holder <NUM> by means of an annular spring 129a. The disk <NUM> consists of a metallic material that can be attracted by a magnet.

The spindle flange <NUM> is also injection molded in one piece and consists in the exemplary embodiment of the same material as the tool holder <NUM>. The spindle flange <NUM> further has an annular spindle disk <NUM> which adjoins the indentation <NUM>. The spindle disk <NUM> has a substantially larger outer diameter than the collar <NUM>.

Three recesses <NUM> are rotationally symmetrically formed in the spindle disk <NUM>, each at a distance of <NUM>°. Each recess <NUM> has two opposing pairs of spring elements <NUM>. The free ends <NUM>' of the spring elements <NUM> form an approximately circular outline.

<FIG> and <FIG> show two tool spindles <NUM>, <NUM>' of the apparatus <NUM>, as already described above. It can be seen from <FIG> and <FIG> that in each tool spindle <NUM>, <NUM>'; <NUM>, <NUM>' a lifting rod <NUM> is mounted in a spindle shaft <NUM> in a manner known per se, in such a way that the lifting rod <NUM> is arranged movably in the direction of the Z-axis of the apparatus <NUM>. For this purpose, a lifting cylinder <NUM> is provided in each tool spindle <NUM>, <NUM>', <NUM>, <NUM>' in a manner known per se, which cylinder in the exemplary embodiment operates pneumatically and is operatively connected to the lifting rod <NUM>.

In the exemplary embodiment, the lifting rod <NUM> has a maximum oscillation stroke H of <NUM> (cf.

<FIG> and <FIG> further show that both the spindle shaft <NUM> and the lifting rod <NUM> protrude from the spindle head <NUM>.

The lifting rod <NUM> serves in a manner known per se for an oscillating infeed or movement of the processing tool <NUM> received on each tool spindle <NUM>, <NUM>'; <NUM>, <NUM>' to the optical workpiece <NUM> during the processing.

The spindle head <NUM> covering the free end of the tool spindles <NUM>, <NUM>' is connected in a usual manner to a bellows <NUM>. The plate-shaped free end of the spindle head <NUM> has three bolts <NUM>, which are arranged rotationally symmetrically to one another at a distance of <NUM>°, respectively. The bolts <NUM> have a bolt head 312a and an annular recess 312b located behind it.

A cap <NUM> is screwed onto the lifting rod <NUM> in a manner known per se, the free surface 315a of which is formed as a magnet (cf. <CIT>, the disclosure of which is expressly referred to).

<FIG> shows how the spindle disk <NUM> of the spindle flange <NUM> is fixed to the spindle head <NUM>. The bolts <NUM> are guided through the recesses <NUM> made in the spindle disk <NUM>. In the process, the spring elements <NUM> are bent up in the direction of the bellows <NUM> until each bolt head 312a passes through the corresponding recess. The spring elements <NUM> then snap back into their initial position and at the same time engage in the annular recess 312b, thus engaging behind the bolt head 312a. Thus, the spindle disk <NUM> of the spindle flange <NUM> is securely held on the spindle head <NUM>.

In <FIG> it can be seen that when the spindle disk <NUM> is fixed to the spindle head <NUM>, the lifting rod <NUM> with the cap <NUM> engages in the annular holder body <NUM> of the tool holder <NUM>. In the process, the disk <NUM> is attracted by the magnet of the free surface 315a of the cap <NUM> until the two parts are connected to each other in a force-fitting manner. This facilitates the fixing of the spindle disk <NUM> to the spindle head <NUM> and contributes to a firm hold of the tool holder <NUM> on the tool spindle.

In the exemplary embodiment, the tool spindles <NUM>, <NUM>'; <NUM>, <NUM>' are equipped with a processing tool <NUM> according to <FIG> and <FIG>.

In the exemplary embodiment, the processing tool <NUM> is a polishing tool <NUM> for polishing optical surfaces, in particular the prescription surfaces of lenses for eyeglass lenses.

In the exemplary embodiment, the polishing tool <NUM> has a circular cylindrical rotational symmetry.

In the illustrated exemplary embodiment, the processing tool <NUM> has a base body <NUM> with a base plate <NUM>, an intermediate layer <NUM> in the form of a foam carrier, and a polishing film or polishing foil <NUM>.

In the exemplary embodiment, the base body <NUM> is rigid, but at least harder than the intermediate layer <NUM> and the polishing foil <NUM>, in order to provide the polishing tool <NUM> with the necessary stability and to allow it to be fixed to the tool spindles <NUM>, <NUM>'; <NUM>, <NUM>'. Suitable materials for the base body <NUM> are rigid PVC (uPVC) materials.

It is expedient that the base body <NUM> is formed in one piece, for example injection molded.

The intermediate layer <NUM> is received in a precisely dimensioned recess 323b of the workpiece-side base surface 323a of the base plate <NUM> and is firmly connected to the base plate <NUM>, in the exemplary embodiment glued or adhesively bonded.

In a manner known per se, the recess 323b has a defined spherical curvature which produces a corresponding deformation of the intermediate layer <NUM> and thus a corresponding spherical curvature of the polishing foil <NUM>.

The radius of curvature of the recess 323b is between <NUM> and <NUM>,<NUM>, typically between <NUM> and <NUM>.

Compared to the prior art, larger radii of curvature of the recess 323b have proven to be effective in order to be able to polish larger processing surfaces of the lenses and/or to increase the material removal during polishing.

Of course, both convex and concave curvatures (i.e., positive or negative radii of curvature) of recess 323b may be provided to allow optical workpieces <NUM> with concave or convex optical surfaces, respectively, to be processed.

In the exemplary embodiment, an RFID chip <NUM> is embedded in a precisely dimensioned recess 324b of the spindle-side base surface 324a of the base plate <NUM> and is firmly connected to the spindle-side base surface 324a, e.g. cast on or glued or adhesively bonded.

Each RFID chip <NUM> can be read and/or overwritten in a manner known per se by means of a read-write device.

In the apparatus <NUM>, each RFID chip <NUM>, i.e. each processing tool <NUM>, is assigned its own read-write device (not shown). The corresponding two or four read-write devices are recessed in pairs in the spindle housing <NUM> in a manner known per se, such that a first pair of read-write devices can be assigned to the processing tools <NUM> on the upper tool spindles <NUM>, <NUM>' and a second pair of read-write devices can be assigned to the processing tools <NUM> on the lower tool spindles <NUM>, <NUM>'.

In the exemplary embodiment, the second pair of read-write devices is recessed in the tool spindle side region of the spindle housing <NUM> such that when the workpiece spindles <NUM>, <NUM>' are in their loading or unloading position, it can interact with the RFID chips <NUM> of the processing tools <NUM> on the lower pair of spindles <NUM>, <NUM>'.

Further, in the exemplary embodiment, the first pair of read-write devices is arranged on the opposite side of the spindle housing <NUM> in an area away from the tool spindles. By pivoting the spindle housing <NUM> about its B axis by <NUM>° (with a cover of the working chamber <NUM> open), the first pair of read-write devices can interact with the RFID chips <NUM> of the processing tools <NUM> of the lower spindle pair <NUM>, <NUM>'.

On the one hand, the RFID chips <NUM> and/or the read-write devices associated therewith serve to identify the processing tools <NUM>.

Further, in the exemplary embodiment, the read-write devices overwrite each work cycle of the processing tools <NUM> on their respective RFID chips <NUM> so that the number of work cycles, service life, and approaching wear of each processing tool <NUM> are monitored.

In the exemplary embodiment, an annular receiving region for receiving and centering the tool holder <NUM> is formed on the spindle-side base surface 324a of the base body <NUM> or base plate <NUM> in the form of four spring elements <NUM>, preferably spring tongues, and four spring elements <NUM>, preferably spring tongues.

The spring elements <NUM> are substantially cuboidal in shape. An internal chamfer 326a is formed at their free ends <NUM>' and a lateral chamfer 326b is formed at one side.

In contrast to the spring elements <NUM>, the spring elements <NUM> have receiving openings <NUM>', whereby two legs <NUM>, <NUM> with free ends <NUM>', <NUM>' as well as narrow regions <NUM>" are formed.

The legs <NUM> have the same height as the spring elements <NUM> and are also provided with an internal chamfer 328a.

The leg <NUM> has a lower height than the spring tongue or spring element <NUM> and is formed essentially as a cuboid frustum, wherein all four edges <NUM>" of the cuboid frustum have a different height.

<FIG> further shows that the internal chamfer 326a of each spring tongue or spring element <NUM> is arranged adjacent to a leg <NUM> of the spring tongue or spring element <NUM>.

The connection of the recess 323b in the workpiece-side base surface 323a of the base plate <NUM> of the base body <NUM> to the intermediate layer <NUM> is designed in such a way that the torque of the tool spindle <NUM>, <NUM>'; <NUM>, <NUM>' can be transmitted from the base body <NUM> to the intermediate layer <NUM>.

In the illustrated exemplary embodiment, the recess 323b and the intermediate layer <NUM> are adhesively bonded together.

The diameter of the intermediate layer <NUM> in the exemplary embodiment is between <NUM> and <NUM>.

The intermediate layer <NUM> is formed in two parts.

A first part <NUM> is directly (adhesively) bonded to the recess 323b of the base plate <NUM>. A second part <NUM> is directly (adhesively) bonded to the first part <NUM>.

The polishing foil <NUM> is directly (adhesively) bonded to the second part <NUM>.

In the exemplary embodiment, both parts are made of a polyurethane foam (PUR foam), wherein the first part <NUM> preferably consists of a closed-cell PUR foam, while the second part <NUM> preferably consists of a mixed-cell PUR foam, in order to reduce the influence of the polishing agent on the material properties of the second part <NUM>. Other configurations of the foams and/or other materials for the intermediate layer <NUM> are of course conceivable.

The first part <NUM> of the intermediate layer <NUM> has a higher static modulus of elasticity than the second part <NUM> of the intermediate layer <NUM>, by a factor of at least <NUM>; however, an increase by a factor of <NUM> or <NUM> is also possible. Accordingly, the first part <NUM> of the intermediate layer <NUM> is harder than the second part <NUM> of the intermediate layer <NUM>.

In the exemplary embodiment, the static modulus of elasticity of the first part <NUM> is more than <NUM> N/mm<NUM> but less than <NUM> N/mm<NUM>. Good results are achieved with a static modulus of elasticity between <NUM> and <NUM> N/mm<NUM>.

In the exemplary embodiment, the static modulus of elasticity of the second part <NUM> is more than <NUM> N/mm<NUM> but less than <NUM> N/mm<NUM>. Good results are achieved with a static modulus of elasticity between <NUM> and <NUM> N/mm<NUM> as well as between <NUM> and <NUM> N/mm<NUM>.

Accordingly, the first part <NUM> of the intermediate layer <NUM> has a greater compression hardness than the second part <NUM> of the intermediate layer <NUM>, by at least a factor of <NUM>; however, an increase by a factor of <NUM> or <NUM> is also possible.

In the exemplary embodiment, the compression hardness of the first part <NUM> is between <NUM> N/mm<NUM>, and <NUM> N/mm<NUM>. Good results are achieved with a compression hardness between <NUM> and <NUM> N/mm<NUM>, in particular <NUM> N/mm<NUM>.

In the exemplary embodiment, the compression hardness of the second part <NUM> is between <NUM> N/mm<NUM> and <NUM> N/mm<NUM>. Good results are achieved with a compression hardness between <NUM> and <NUM> N/mm<NUM>, in particular with compression hardnesses of <NUM> and <NUM> N/mm<NUM>.

The first, harder part <NUM> of the intermediate layer <NUM> is formed significantly thicker than the second, softer part <NUM> of the intermediate layer <NUM> to enable precise polishing and to reduce the center offset of the processing tool <NUM> during the polishing process.

The first part <NUM> is at least a factor of <NUM>, but at most a factor of <NUM> thicker than the second part <NUM> of the intermediate layer <NUM>. Good results are achieved with a thickness of the first part <NUM> between <NUM> and <NUM> and a thickness of the second part <NUM> between <NUM> and <NUM>.

The total thickness of the intermediate layer <NUM> should not exceed <NUM>.

The polishing foil <NUM> is made of a polyurethane material and has a larger diameter than the intermediate layer <NUM>, so that it protrudes over the edges of the intermediate layer <NUM>.

In the exemplary embodiment, the polishing foil <NUM> further has a thickness of <NUM> to <NUM>, wherein good results are achieved with a thickness of <NUM>.

The radius of curvature of the polishing foil <NUM> or its polishing surface <NUM> is typically larger than the radius of curvature of the recess 323b, typically by at least <NUM>. This depends, in a manner known per se, on the thickness of the intermediate layer <NUM> as well as the material properties of intermediate layer <NUM> and polishing foil <NUM>.

Compared to the prior art, larger radii of curvature of the recess 323b and/or polishing surface <NUM> have proven useful in order to be able to polish larger processing areas of the lenses and/or increase the amount of material removed during polishing.

The connection of the processing tool <NUM> to the tool holder <NUM> is shown enlarged in <FIG>.

A torque can be transmitted from the tool spindle <NUM>, <NUM>'; <NUM>, <NUM>' to the processing tool <NUM> via the tool holder <NUM> and/or the spindle disk <NUM>.

The connection of the processing tool <NUM> to the tool holder <NUM> is reversible, so that the change of the processing tool <NUM> in the event of wear or damage can be carried out manually in a simple manner.

As can be seen from <FIG>, the spring elements <NUM>, <NUM> of the receiving region of the base body <NUM> are pushed onto the annular holder head <NUM> of the tool holder <NUM> in such a way that the free ends <NUM>' of the spring elements <NUM> and the free ends <NUM>', <NUM>' of the legs <NUM>, <NUM> abut on the collar <NUM> of the tool holder <NUM>.

In this case, the legs <NUM>, <NUM> of each spring tongue or spring element <NUM> each enclose a retaining lug or retaining element <NUM> of the tool holder <NUM>. The narrow regions <NUM>" formed by the receiving openings <NUM>' lie in this case behind the retaining lug head or retaining element head 124a, in such a way that the base body <NUM> is held in a clamping manner.

Furthermore, it can be seen that the retaining lug heads or retaining element heads 124a do not completely fill the receiving openings <NUM>'. This has the advantage that greater variations in the manufacturing tolerances are acceptable when manufacturing the base body <NUM>, for example by means of injection molding, so that the base body <NUM> of the processing tool <NUM> can be regarded as a mass-produced article that can be manufactured inexpensively.

The tool holder <NUM> is characterized in particular in that a processing tool <NUM> is rigidly held, i.e. any moving and/or elastic parts between the tool holder <NUM> and the processing tool <NUM>, such as in particular a ball head, rubber-elastic parts or flexure bearings, are dispensed with. In other words, the necessary deflection of the processing tool <NUM> during the processing operation, in particular the polishing process, takes place exclusively by means of the two-part elastic intermediate layer <NUM>. Thus, the processing tool <NUM> can be controlled and/or guided much more precisely during the processing operation than is known in the prior art.

The tool holder <NUM> is further characterized in that it is firmly mounted on the spindle head of the polishing spindle and only the processing tool <NUM> itself is manually exchanged in the event of wear or damage.

The preferred design of the spring elements <NUM>, <NUM> has the effect that an operator can fit or plug the base body <NUM> of the processing tool <NUM> onto a tool holder <NUM> without requiring a free field of view for this purpose.

For this purpose, the basic body <NUM> is pushed onto the annular holder head <NUM> until resistance is felt (because, for example, the free ends of the spring elements <NUM>, <NUM> rest or abut on the retaining elements <NUM>). Then the base body <NUM> is rotated clockwise on the holder head <NUM> until resistance is again felt. In this position, the retaining elements <NUM> rest against the chamfered free ends <NUM>' of the longer legs <NUM> so that clockwise movement is blocked. Now the operator knows that the retaining elements <NUM> are positioned opposite the receiving openings <NUM>' corresponding thereto. The base body <NUM> is now in the correct position on the annular holder head <NUM> and can now be pushed on, as shown in <FIG>.

As a result, a structurally simple, stable and joint-free and/or rigid connection of the processing tool <NUM> via the tool holder <NUM> to the spindle head <NUM> of each tool spindle <NUM>, <NUM>'; <NUM>, <NUM>' is obtained. Furthermore, the processing tool <NUM> can be mounted or plugged on the tool holder <NUM> in a simple manner as described and can be removed or pulled off again when changing tools.

The apparatus <NUM> of the shown embodiment operates preferably as follows. Individual method steps may be implemented differently or in different order or omitted completely, for example steps regarding transfer of workpieces, in particular if the individual devices/stations in the apparatus have a different arrangement than shown.

As a starting point, it is assumed that a first pair of optical workpieces <NUM>, preferably optical lenses for eyeglass lenses, is cleaned in the cleaning station <NUM> and a second pair of optical workpieces <NUM> is processed, in the exemplary embodiment polished, in the working chamber <NUM>.

At the same time, the empty conveying containers <NUM>' for accommodating or receiving these two pairs of workpieces <NUM> are moved forward on the conveyor device <NUM> in a synchronized manner past the working chamber <NUM> in the direction of the cleaning station <NUM>. Behind them follow conveying containers <NUM>' containing optical workpieces <NUM> to be processed.

The handling device <NUM> is positioned at the level of the cleaning station <NUM>, since the processing operation in the working chamber <NUM>, in this exemplary embodiment the polishing operation, takes considerably more time than the cleaning operation in the cleaning station <NUM>.

As soon as the cleaning operation is finished, the cleaning station <NUM> is opened. The workpiece spindles <NUM>, <NUM>' with the cleaned and blocked optical workpieces <NUM> are moved upwards in the direction of the X axis of the apparatus <NUM> until the optical workpieces <NUM> protrude from the cleaning station <NUM>.

The handling device <NUM> grips the cleaned optical workpieces <NUM> at their edges by means of the second pick-up devices <NUM> (here: <NUM>-finger grippers) of its holding devices <NUM>, <NUM>' and removes the optical workpieces <NUM> from the workpiece spindles <NUM>, <NUM>'. The swivel arm <NUM> of the handling device <NUM> swivels about its swivel axis <NUM>' in the direction of the conveyor device <NUM>. The cleaned optical workpieces <NUM> are deposited in the conveying container <NUM>' assigned to them, which in the meantime has been further advanced on the conveyor device <NUM> along the apparatus <NUM>.

The conveying container <NUM>' with the finished optical workpieces <NUM> deposited therein is transported out of the apparatus <NUM> on the conveyor device <NUM>.

The handling device <NUM> now moves on the guide rails <NUM> along the Y-axis of the apparatus <NUM> in the direction of the working chamber <NUM>.

Now the cross strut <NUM> of the swivel arm <NUM> swivels about its swivel axis <NUM>' in such a way that now the first pick-up devices <NUM> (here: suction cups) are oriented towards the conveying containers <NUM>'. A third pair of unprocessed optical workpieces <NUM> is gripped centrally by the first pick-up devices <NUM> (here: suction cups).

Subsequently, the swivel arm <NUM> of the handling device <NUM> swivels about its swivel axis <NUM>' in the direction of the working chamber <NUM>, and the cross strut <NUM> of the swivel arm <NUM> swivels about its swivel axis <NUM>' in such a way that now the second pick-up devices <NUM> (here: <NUM>-finger grippers) are oriented towards the working chamber <NUM>.

In the meantime, the polishing process with respect to the second pair of optical workpieces <NUM> is completed, and the working chamber <NUM> is opened. The B-axis housing <NUM> with the gear motor <NUM> located therein and the B-axis disk or B-axis flange <NUM> is lifted along the X-axis of the apparatus <NUM> together with the spindle housing <NUM> and the workpiece spindles <NUM>, <NUM>' accommodated therein. This brings the finished polished optical workpieces <NUM> held on the workpiece spindles <NUM>, <NUM>' within reach of the second pick-up devices <NUM> (here: <NUM>-finger grippers) of the holding devices <NUM>, <NUM>'. These now grip the second pair of finished polished optical workpieces <NUM> at the edge and remove the optical workpieces <NUM> from the workpiece spindles <NUM>, <NUM>'.

The cross strut <NUM> of the swivel arm <NUM> then swivels about its swivel axis <NUM>' in such a way that the first pick-up devices <NUM> (here: suction cups) loaded with the third pair of optical workpieces <NUM> to be processed are now oriented toward the working chamber <NUM>. The workpiece spindles <NUM>, <NUM>' are loaded with the third pair of optical workpieces <NUM>. The workpiece spindles <NUM>, <NUM>' are lowered into the working chamber <NUM> along the X-axis of the apparatus <NUM> in the reversal of the operation described above. The working chamber <NUM> is closed and the processing operation, in this case the polishing process, begins.

The time interval between removing the finished polished optical workpieces <NUM> from the workpiece spindles <NUM>, <NUM>' and reloading them with optical workpieces <NUM> to be polished is approximately <NUM> seconds. This time interval is used to perform an inspection of the processing tools <NUM>.

For this purpose, the perpendicular or vertical laser beam <NUM> described further above is directed at the processing tool <NUM> of the upper tool spindle <NUM>' closest to the device <NUM>, and the oblique laser beam <NUM> described further above is directed at the processing tool <NUM> of the corresponding lower tool spindle <NUM>', while the processing tools <NUM> are slowly rotated. The laser beams <NUM>, <NUM> thereby detect the circumferential surfaces of the base body <NUM> and intermediate layer <NUM> of each processing tool <NUM> as well as the circumferential edge of the projecting rear surface of the polishing foil <NUM> facing the intermediate layer <NUM>.

Subsequently, the device <NUM> for tool inspection moves along the Y-axis of the apparatus <NUM> on the profile or guide rails <NUM> to the tool spindles <NUM>, <NUM>. Now, the processing tools <NUM> received on these tool spindles <NUM>, <NUM> are inspected as described.

This inspection of the processing tools <NUM> takes significantly less than <NUM> seconds, so it is completed before the handling device <NUM> is ready to reload the workpiece spindles <NUM>, <NUM>' with optical workpieces <NUM> to be polished.

As a result, a <NUM>° coverage of the entire circumferential surfaces of all tools <NUM> is obtained.

Three types of defects can be identified:.

The risk for total loss is minimized by detecting cracks in the intermediate layer <NUM> so that the affected processing tool <NUM> can be exchanged before total loss.

After performing the tool inspection and reloading the workpiece spindles <NUM>, <NUM>', the handling device <NUM> moves on the guide rails <NUM> along the Y-axis of the apparatus <NUM> in the direction of the cleaning station <NUM>.

Now the cross strut <NUM> of the swivel arm <NUM> swivels about its swivel axis <NUM>' in such a way that now the second pick-up devices <NUM> (here: <NUM>-finger grippers) loaded with the finished polished second pair of optical workpieces <NUM> are oriented towards the cleaning station <NUM>. The second pair of workpieces <NUM> to be cleaned is placed on the workpiece spindles <NUM>, <NUM>' of the cleaning station <NUM>. The workpiece spindles <NUM>, <NUM>' are moved downward in the direction of the X-axis of the apparatus <NUM> in reversal of the operation described above until the optical workpieces <NUM> are completely received in the cleaning station <NUM>. The cleaning station <NUM> is closed and the cleaning process begins.

Now the cycle just described starts again from the beginning.

According to a particularly preferred aspect of the present invention, the following polishing process or polishing method can be carried out with the apparatus <NUM> in combination with the tool holder <NUM> and the processing tool <NUM> (cf. <FIG>):
As soon as the workpiece spindles <NUM>, <NUM>' are loaded and the working chamber <NUM> is closed, the spindle plate or spindle housing <NUM> swivels by <NUM>° about its B axis so that the processing tools <NUM> and the workpieces <NUM> to be polished are arranged opposite each other.

Now, first the upper tool spindle pair <NUM>, <NUM>' is fed or advanced or moved along the Z axis of the apparatus <NUM> in a manner known per se. The path length of the infeed stroke or infeed lift depends on the geometry of the surface to be processed of the respective optical workpieces <NUM>.

During the polishing process, only the oscillation stroke or oscillation lift of the tool spindles <NUM>, <NUM>' (lifting rods <NUM>, see <FIG>) operates.

After completion of the polishing process, the finished polished optical workpieces <NUM> are either removed from the working chamber <NUM> (single-stage polishing) or they are moved down along the X-axis of the apparatus <NUM> and arranged opposite the second pair of tool spindles <NUM>, <NUM>', after which the polishing process starts again (two-stage polishing, pre-polishing and post-polishing).

The processing tool <NUM> and/or the polishing foil <NUM> has a tool axis which forms a center axis Mwz and/or rotation axis Rwz. Typically, the tool axis corresponds to the center axis Mws of the workpiece spindles <NUM>, <NUM>'.

In an exemplary embodiment of a polishing method, the radius of curvature of the polishing surface <NUM> of the polishing foil <NUM> is larger than the largest radius of curvature of the optical workpiece <NUM> to cause an annular contact surface when the processing tool <NUM> is pressed against the optical workpiece <NUM>. In this way, the removal rate can be increased compared to point contact surfaces and/or when the radius of curvature of the polishing surface <NUM> is smaller.

During the polishing process, the polishing surface <NUM> of the polishing foil <NUM> and the optical surface of the optical workpiece <NUM> to be polished are in direct contact with each other. Here, the polishing surface <NUM> lies with its entire surface on the optical surface.

The polishing pressure is kept constant during the polishing process within a tolerance range and is between <NUM> and <NUM> N/mm<NUM>.

The diameter of the optical workpieces <NUM> to be polished is typically larger than the diameter of the polishing foil <NUM>.

During the polishing process, the rotational speed of the tool spindles <NUM>, <NUM>'; <NUM>, <NUM>' is typically greater than the rotational speed of the workpiece spindles <NUM>, <NUM>' by a factor of <NUM>, <NUM> or <NUM>, wherein the rotational speed of the tool spindles <NUM>, <NUM>'; <NUM>, <NUM>' is <NUM>,<NUM> rpm or <NUM>,<NUM> rpm.

In this process, the optical workpiece <NUM> typically rotates in the direction of the arrow W in the opposite direction to the processing tool <NUM>, which rotates in the direction of the arrow BW (cf.

The duration of the polishing process is typically between <NUM> and <NUM> seconds.

During the polishing process, the two-part intermediate layer <NUM> of the processing tool <NUM> is compressed, wherein the second, softer part <NUM> is more compressed than the first, harder part <NUM>. Typically, the intermediate layer <NUM> is compressed by <NUM> to <NUM>%, wherein good results are achieved with a compression of between <NUM> and <NUM>%. The above values refer to the original thickness of the intermediate layer <NUM>.

Furthermore, the polishing foil <NUM> can yield or give way in radial direction, i.e. transversely to the center axis Mwz of the tool spindles <NUM>, <NUM>'; <NUM>, <NUM>', in order to enable adaptation to radii of curvature of the surface to be polished of the optical workpiece <NUM> changing in circumferential direction. This is the case, for example, with toric surfaces.

For example, the intermediate layer <NUM> may be more compressed in a deflected or off-center processing position at the edge of the optical workpiece <NUM> than in the center of the optical workpiece <NUM>. This creates a center offset.

Due to the joint-free and/or rigid structure of the tool holder <NUM>, the deflection and/or center offset of the processing tool <NUM> occurs solely by means of the two-part intermediate layer <NUM>.

This, in combination with the structure of the intermediate layer <NUM> with a harder first part <NUM> and a softer second part <NUM>, has the effect that the processing tool <NUM> and/or the center axis MBW of the processing tool <NUM> can be moved up to or over the edge of the optical workpiece <NUM> without the polishing foil <NUM> lifting off from the optical surface of the optical workpiece <NUM> to be polished.

Known apparatuses with an articulated or joint connection of the processing tool to the tool spindle (for example, with a ball-and-socket joint or a flexure bearing), in contrast, would tilt in a processing position in which the center axis of the processing tool is moved over the edge of the optical workpiece <NUM> in such a way that the polishing foil of the processing tool loses contact with the optical surface of the optical workpiece to be polished.

With the processing tool <NUM>, it is thus possible to perform a surface polishing and/or a polishing with a high removal rate even in the edge area of the optical workpiece <NUM> continuously and with the required accuracy.

The proposed polishing process or polishing method results in a longer service life of the processing tools <NUM>.

Claim 1:
Apparatus (<NUM>) for processing, in particular polishing, optical workpieces (<NUM>), in particular lenses or spectacle glasses,
with a working chamber (<NUM>) having a chamber housing (<NUM>) which encloses a working space (<NUM>),
wherein workpiece spindles (<NUM>, <NUM>') for receiving and holding the optical workpieces (<NUM>) and tool spindles with processing tools (<NUM>) receivable thereon for processing the optical workpieces (<NUM>) are arranged in the working space (<NUM>),
wherein the tool spindles are arranged rotatably about their center axes (Mwz),
wherein the tool spindles are arranged to be linearly movable along their center axes (Mwz),
characterized
in that at least two pairs of tool spindles (<NUM>, <NUM>'; <NUM>, <NUM>') are provided within the working space (<NUM>),
in that at least one rotational drive device (<NUM>) is provided for the at least two pairs of tool spindles (<NUM>, <NUM>'; <NUM>, <NUM>'),
in that at least one linear drive device (<NUM>) is provided for the at least two pairs of tool spindles (<NUM>, <NUM>'; <NUM>, <NUM>') along their center axes (MWZ).