EP2686137B1 - Device for the fine machining of optically active surfaces on in particular spectacle lenses - Google Patents

Description

TECHNICAL AREA

The present invention relates generally to a device for fine machining of optically active surfaces according to the preamble of claim 1. In particular, the invention relates to a device for fine machining the optically effective surfaces of spectacle lenses, as in so-called "RX workshops", i. Production facilities for the production of individual spectacle lenses are widely used according to prescriptions.

If the following example of workpieces with optically active surfaces of "lenses" is mentioned, including not only eyeglass lenses made of mineral glass, but also eyeglass lenses from all other common materials, such as polycarbonate, CR 39, HI index, etc., including plastic be understood.

STATE OF THE ART

The machining of the optically effective surfaces of spectacle lenses can be roughly subdivided into two processing phases, namely first the pre-processing of the optically effective surface to produce the recipe macrogeometry and then the fine processing of the optically effective surface to eliminate Vorbearbeitungsspuren and obtain the desired microgeometry. While the pre-processing of the optically active surfaces of spectacle lenses, inter alia, depending on the material of the spectacle lenses by grinding, milling and / or turning, the optically effective surfaces of spectacle lenses in the finishing usually a fine grinding, Lapping and / or polishing process, what to use a corresponding machine.

Above all hand-fed polishing machines in RX workshops are usually designed as "twin machines", so that advantageously the two lenses of an "RX job" - a lens prescription always consists of a pair of spectacle lenses - can be simultaneously finished. Such a "twin" polishing machine is for example from the documents US-A-2007/0155286 and US-A-2007/0155287 known.

In this prior art polishing machine projecting two parallel, each rotatable about a rotation axis, but otherwise stationary workpiece spindles from below into a working space where they face two polishing tools, so that a polishing tool of a workpiece spindle and the other polishing tool of the other workpiece spindle is assigned. Each polishing tool is freely rotatably mounted on a spherical bearing at a projecting from above into the working space piston rod of a respective, arranged above the working space piston-cylinder arrangement by means of the respective polishing tool can be lowered or raised individually with respect to the associated workpiece spindle. The two piston-cylinder assemblies are further by means of a linear drive together in a direction perpendicular to the axes of rotation of the workpiece spindles with respect to a front side of the polishing machine moved back and forth and also by means of a pivot drive together tiltable about a pivot axis, which is also perpendicular to the axes of rotation of the workpiece spindles , but runs parallel to the front of the polishing machine. By means of the pivot drive, the angular position between the axes of rotation of the tools and workpieces can be preset before the tools are lowered by means of the piston-cylinder assemblies on the workpieces. During the actual polishing process the workpieces are rotationally driven, with the tools in working engagement with the workpieces being frictionally entrained by friction, while the linear drive causes the tools to be alternately moved back and forth with respect to the front of the polishing machine so that the tools are relatively small Keep moving back and forth across the workpieces (so-called "tangential kinematics").

Advantages of this "twin" polishing machine include the fact that it is constructed from inexpensive components in device-simple manner, is very ergonomic for a manual feed and also requires very little footprint in the RX workshop due to their extremely compact, very narrow design , It would be desirable, however, if other polishing methods could be performed on such a polishing machine. So are those in the pamphlets EP-A-1 473 116 . EP-A-1 698 432 and EP-A-2 014 412 disclosed flexible polishing tools designed for polishing, in which in addition to the workpiece and the tool itself is driven in rotation, whereby the polishing times - compared to polishing methods in which the tool is only taken by friction - can be significantly shortened.

The forming the preamble of claim 1 DE-A-102 50 856 discloses in this connection a polishing apparatus (see Figs Fig. 5 to 9 ) with a rotary electric drive for the polishing tool, which as such has a stator and a rotor, and with a pneumatic piston-cylinder unit for axial deflection of the polishing tool along a longitudinal axis. Here, the arrangement of the rotary and axial drives is made such that a rotatably mounted in a housing about a rotation axis spindle shaft assembly ("rotor" in the linguistic use of the above document), which at their extending from the housing end the actual polishing tool, is rotatably driven by a toothed belt drive of the electric rotary drive, which is laterally offset in the housing, arranged parallel to the axis of rotation; the pneumatic piston-cylinder unit and an associated axial guide, however, are integrated in the spindle shaft assembly, thus rotationally driven, which is why the piston-cylinder unit for supplying pressure medium requires a compressed air rotary feedthrough. This polishing device has a relatively large space requirement, which is why it is not suitable for use in the above-described "twin" polishing machine.

Finally, in the post-published document DE-A-10 2009 041 442 the same applicant discloses a device for fine machining the optically active surfaces of particular spectacle lenses, having a tool receiving portion having a spindle shaft which is rotatably mounted in a spindle housing about a tool axis of rotation, a rotor and a stator having electric rotary drive, by means of which with the Rotor operatively connected spindle shaft is rotatably driven about the tool rotation axis, and an adjusting device, by means of which the tool receiving portion with respect to the spindle housing in the direction of the tool rotation axis is axially displaceable. A special feature of this device is that the rotor and the stator are arranged coaxially with the spindle shaft, by means of the adjusting at least the rotor together with the spindle shaft with respect to the spindle housing in the direction of the tool axis of rotation is axially displaceable, which in particular a very compact design conditionally.

For very large curvatures or larger changes in curvature over the circumference of the processed optically active surfaces that require larger Axialhübe the tool, the use of this device has its limits. Because spindle shaft and Rotor, which have a considerable mass, must be moved along with the respective Axialhub, possibly required rapid axial compensatory movements of the tool are not possible.

TASK

The invention has for its object to provide a simple and inexpensive constructed device for fine machining of optically effective surfaces of particular eyeglass lenses, driven by the example, a polishing tool rotationally and axially displaced - the tool should also be able to rapid axial compensatory movements To carry out - and which is still very compact, so that they are approximately in a very narrow-built "twin" polishing machine, such as The polishing machine described above, can be used.

PRESENTATION OF THE INVENTION

This object is achieved by the features specified in claim 1. Advantageous or expedient developments of the invention are subject matter of the claims 2 to 10.

According to the invention, in a device for fine machining of optically active surfaces on in particular spectacle lenses, which (i) a spindle receiving a tool receiving portion which is rotatably mounted in a spindle housing about a tool axis of rotation, and (ii) a rotor and a stator having electrical Rotary drive comprises, by means of which the spindle shaft operatively connected to the rotor is rotatably driven about the tool rotation axis, while the tool receiving portion is axially displaceable in the direction of the tool rotation axis; the rotor and the stator of the electric Rotary drive and the spindle shaft arranged coaxially in the spindle housing, which in turn in a guide tube in the direction of the tool axis of rotation defined axially displaceable (linear actuator axis Z) is guided, wherein the spindle shaft is formed as a hollow shaft, via which executed for receiving a membrane chuck tool holding portion with a fluid can be acted upon.

Characterized in that according to the invention, the rotor and the stator of the electric rotary drive are arranged together with the spindle shaft on one and the same axis, the device is advantageously compact. In addition, the spindle shaft can be directly rotated without any play or slip-prone transmission elements, such as gears, timing belts. Like. Would be required, which reduces the overall device complexity, significantly reduces the space requirement for this drive and also avoids transmission-related efficiency losses and wear ,

With respect to the axial adjustment of the tool quasi a division is provided according to the invention: First, the spindle housing - and thus provided on the spindle shaft tool receiving portion - guided axially displaceable in the guide tube in the direction of the tool axis of rotation, so that held in the tool receiving portion membrane chuck tool - rather slowly - can be moved over relatively large axial paths and positioned with respect to the workpiece to be machined. On the other hand, the tool receiving portion for receiving a membrane chuck tool, as for example from the aforementioned publications EP-A-1 473 116 . EP-A-1 698 432 and EP-A-2 014 412 is known, executed, which is there acted upon by the hollow spindle shaft with a fluid or pressure medium, so that, for example, a held on the membrane chuck polishing pad the respective processing requirements according to fast or sensitive axial compensatory movements If, for example, workpieces with very large curvatures or larger changes in curvature are machined over the circumference. In this context, it should be noted that, for example, for use of the device according to the invention in a polishing machine for spectacle lenses, the axial movement of the polishing tool should be as smooth as possible. This property is particularly important for the polishing of spectacle lenses with toric, atoric or progressive surfaces with high deviation from the rotational symmetry, so that the polishing tool always full or flat and with sensitive adjustable polishing force (or contact force) rests on the lens. If, in fact, the polishing tool would lose the surface contact to the workpiece surface during its high-speed rotary motion only for a short time, the coarser grains and agglomerates present in the polishing agent could cause scratching of the polished spectacle lens surface.

Moreover, the coaxial arrangement of axial guide for the rather long axial tool movements (spindle housing in the guide tube) and pressure medium supply for the rather short axial tool compensation movements (hollow spindle shaft in the spindle housing) also requires a very compact design of the device.

As a result, the device according to the invention is eminently suitable for use in e.g. the above-described "twin" polishing machine, so that using other polishing methods with rotationally driven polishing tools, the processing times can be significantly reduced (ie, divisor 2), without increasing the low complexity of this polishing machine over charge or their space or space requirement at all to enlarge.

In principle, the spindle housing can consist of one piece in the area of the spindle shaft and rotary drive. Regarding However, it is preferable for simple manufacture and assembly if the spindle housing has a motor housing in which the rotor and the stator of the rotary drive are arranged, and a shaft housing flanged thereto, in which the spindle shaft is rotatably mounted.

In an advantageous embodiment of the device according to the invention, the motor housing can be closed by means of a lid having a through hole in which a rotary feedthrough is fixed for the fluid, which is in fluid communication with the hollow spindle shaft. Here, various measures are conceivable for fastening the rotary feedthrough on the cover, for example a screw connection. Preferably, the rotary feedthrough in the through hole of the lid but frictionally fixed by means of an elastic cable grommet, as they are available at low cost commercially.

In order to easily prevent od the leadership of the spindle housing in the guide tube by liquid polishing agent. Like. Damaged or damaged, may be arranged between the remote from the rotary drive end of the guide tube and the remote from the rotary drive end of the spindle housing, a bellows, the surrounds the spindle housing. Likewise, at the end remote from the rotary drive end of the spindle shaft, a slinger for a liquid finishing means may be mounted to easily protect the Drehabdichtung (such as a pairing of labyrinth seal and radial seal) between the spindle housing and spindle shaft.

For the axial guidance of the spindle housing in the guide tube also various measures are conceivable, eg ball bushings or air bearing bushes. However, since a special smoothness is not required here (more) because the rapid tool (compensation) movements take place in the membrane chuck tool itself, it is in terms of longevity and cost preferred when the spindle housing is guided axially by means of a sliding ring in the guide tube.

Furthermore, it is particularly advantageous to use the above-described device in duplicate in a polishing machine for simultaneously polishing two lenses, which polishing machine (i) a machine housing defining a working space, (ii) two workpiece spindles projecting into the working space, over the two to be polished (Iii) a first linear drive unit, by means of which a first tool carriage is movable along a linear axis which is substantially perpendicular to the workpiece axes of rotation, (iv) a pivot drive unit disposed on the first tool carriage and by means of which a pivot yoke is pivotable about a pivotal adjustment axis that is substantially perpendicular to the workpiece axes of rotation and substantially perpendicular to the linear axis, and (v) a second linear drive unit which is arranged on the pivot yoke and by means of the at least one second tool carriage along a linear adjusting axis is movable, which is substantially perpendicular to the pivoting adjusting axis; in such a way that the two devices with their tool receiving portions each one of the workpiece spindles assigned projecting into the working space and are flanged with their respective spindle housing on the at least one second tool carriage, while the respective guide tube is attached to the pivot yoke, so that the tool axis of rotation each device with the workpiece axis of rotation of the associated workpiece spindle forms a plane in which the respective tool rotation axis with respect to the workpiece axis of rotation of the associated workpiece spindle is axially displaceable and tiltable.

Such a trained and equipped "twin" polishing machine is characterized not only by the fact that it is very compact - inasmuch as it is easy to feed manually - and in a very cost effective way many common drives uses, but in particular by the fact that by the Movement possibilities provided by the invention, namely the active rotational movement possibility of polishing tools mounted thereon, compared with the above-described prior art, the implementation of other, especially faster or more time-efficient polishing process allows.

In a particularly simple and cost-effective embodiment of the polishing machine, only a second tool carriage can be provided for the common axial movement of both spindle housings by means of the second linear drive unit. Due to the given axial mobility in the respective membrane chuck tool, each tool can still be adapted individually to the respective machined surface.

Finally, it is advantageous in particular with regard to once again a simple and cost-effective design of the polishing machine, if both the swivel drive unit and the second linear drive unit are commercially available linear modules, each having a lifting rod which is driven by a spindle drive driven by a DC motor. or can be retracted.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1

eine perspektivische Ansicht einer Poliermaschine für Brillengläser von schräg oben / vorne rechts mit zwei parallel angeordneten, erfindungsgemäßen Vorrichtungen zur Feinbearbeitung der optisch wirksamen Flächen der Brillengläser, wobei zur Freigabe der Sicht auf wesentliche Bauteile bzw. Baugruppen der Maschine und zur Vereinfachung der Darstellung insbesondere die Bedieneinheit und Steuerung, Teile der Verkleidung, Türmechanismen und Scheiben, die Ablagen für Werkstücke und Werkzeuge, die Versorgungseinrichtungen (einschließlich Leitungen, Schläuche und Rohre) für Strom, Druckluft und Poliermittel, der Poliermittelrücklauf sowie die Mess-, Wartungs- und Sicherheitseinrichtungen weggelassen wurden;

Fig. 2

eine im Maßstab gegenüber der Fig. 1 vergrößerte, am Maschinengestell abgebrochene, perspektivische Ansicht der Poliermaschine gemäß Fig. 1 von schräg oben / vorne links, wobei einerseits die in Fig. 1 linke erfindungsgemäße Vorrichtung und eine zugeordnete, flexible Arbeitsraumabdeckung weggelassen wurden, um die Anschlusssituation für die in Fig. 1 linke erfindungsgemäße Vorrichtung zu veranschaulichen, und andererseits die Seitenwände und die Vorderwand des den Arbeitsraum begrenzenden Blechgehäuses, um den Blick auf zwei parallel angeordnete Werkstückspindeln freizugeben, von denen jeweils eine Werkstückspindel jeweils einer der erfindungsgemäßen Vorrichtungen zugeordnet ist;

Fig. 3

eine im Maßstab gegenüber der Fig. 2 nochmals vergrößerte, perspektivische Ansicht der Poliermaschine gemäß Fig. 1 von schräg oben / hinten rechts, wobei gegenüber der Darstellung in Fig. 2 zusätzlich noch das Maschinengestell weggelassen wurde;

Fig. 4

eine Vorderansicht der Poliermaschine gemäß Fig. 1 im Maßstab der Fig. 3 und mit den Vereinfachungen der Fig. 3;

Fig. 5

eine Seitenansicht der Poliermaschine gemäß Fig. 1 von rechts in Fig. 4, erneut im Maßstab der Fig. 3 und mit den Vereinfachungen der Fig. 3, wobei im Gegensatz zur Fig. 4 an der erfindungsgemäßen Vorrichtung ein Membranfutterwerkzeug mit Polierteller montiert ist;

Fig. 6

eine im Maßstab gegenüber den Fig. 1 bis 5 vergrößerte, perspektivische Ansicht einer der erfindungsgemäßen Vorrichtungen aus der Poliermaschine gemäß Fig. 1, mit daran montiertem Membranfutterwerkzeug ohne Polierteller;

Fig. 7

eine Vorderansicht der erfindungsgemäßen Vorrichtung aus Fig. 6;

Fig. 8

eine im Maßstab gegenüber den Fig. 6 und 7 vergrößerte Schnittansicht der erfindungsgemäßen Vorrichtung aus Fig. 6 entsprechend der Schnittverlaufslinie VIII-VIII in Fig. 7; und

Fig. 9

eine abgebrochene Schnittansicht der erfindungsgemäßen Vorrichtung aus Fig. 6 entsprechend der Schnittverlaufslinie IX-IX in Fig. 8, wobei die Vorrichtung allerdings in einem ausgefahrenen Zustand dargestellt ist, in dem sich das an der Vorrichtung montierte, mit einem Polierteller versehene Membranfutterwerkzeug mit einem Brillenglas in Bearbeitungseingriff befindet, welches mittels eines Blockstücks an einer mit gestrichelten Linien angedeuteten Werkstückspindel aufgenommen ist.

In the following the invention will be explained in more detail by means of a preferred embodiment with reference to the attached, partially simplified or schematic drawings. In the drawings show:

Fig. 1

a perspective view of a polishing machine for spectacle lenses obliquely from above / front right with two parallel, inventive devices for fine machining the optically effective surfaces of the lenses, to enable the view of essential components or assemblies of the machine and to simplify the presentation in particular the control unit and controls, parts of the fairing, door mechanisms and washers, the work and tool trays, utilities (including pipes, hoses and pipes) for electricity, compressed air and polishing media, the polishing agent return and the measuring, maintenance and safety devices have been omitted;

Fig. 2

one in scale over the Fig. 1 enlarged, aborted on the machine frame, perspective view of the polishing machine according to Fig. 1 from diagonally above / front left, whereby on the one hand the in Fig. 1 left device according to the invention and an associated, flexible work space cover were omitted to the connection situation for in Fig. 1 to illustrate left device according to the invention, and on the other hand, the side walls and the front wall of the working space bounding sheet metal housing to share the view of two parallel workpiece spindles, each of which a workpiece spindle is assigned to each of the devices according to the invention;

Fig. 3

one in scale over the Fig. 2 again enlarged, perspective view of the polishing machine according to Fig. 1 from diagonally above / behind right, where opposite to the illustration in Fig. 2 in addition still the machine frame was omitted;

Fig. 4

a front view of the polishing machine according to Fig. 1 in the scale of Fig. 3 and with the simplifications of Fig. 3 ;

Fig. 5

a side view of the polishing machine according to Fig. 1 from the right in Fig. 4 , again in the scale of Fig. 3 and with the simplifications of Fig. 3 , whereas contrary to Fig. 4 on the device according to the invention a membrane chuck tool is mounted with polishing plate;

Fig. 6

one in scale over the Fig. 1 to 5 enlarged, perspective view of one of the devices according to the invention from the polishing machine according to Fig. 1 , with attached membrane chuck tool without polishing plate;

Fig. 7

a front view of the device according to the invention Fig. 6 ;

Fig. 8

one in scale over the 6 and 7 enlarged sectional view of the device according to the invention Fig. 6 according to the section line VIII-VIII in Fig. 7 ; and

Fig. 9

a broken sectional view of the device according to the invention Fig. 6 according to the section line IX-IX in Fig. 8 However, the device is shown in an extended state, in which the mounted on the device, provided with a polishing plate membrane chuck tool with a spectacle lens is in working engagement, which by means of a block piece at one with dashed Lines indicated workpiece spindle is added.

DETAILED DESCRIPTION OF THE EMBODIMENT

In the Fig. 1 to 5 is - as a preferred application or location of a device 10 described in detail below for fine machining of optically active surfaces on workpieces, such as lenses L (see. Fig. 5 ) - a polishing machine in "twin" construction, ie for the simultaneous polishing of two lenses L numbered 12.

The polishing machine 12 generally has (i) a machine housing 16 bounding a working space 14, which is mounted on a machine frame 18, (ii) two work piece spindles 20 projecting into the working space 14, via which two lenses L to be polished by means of a common rotary drive 22 (see FIG the Fig. 3 to 5 ) about substantially parallel to each other workpiece rotation axes C1, C2 (C in Fig. 9 (iii) a first linear drive unit 24, by means of which a first tool carriage 26 can be moved along a linear axis X, which runs substantially perpendicular to the workpiece rotation axes C1, C2, (iv) a pivot drive unit 28, is arranged on the first tool carriage 26 and by means of a pivot yoke 30 can be pivoted about a pivot axis B, which is substantially perpendicular to the workpiece axes of rotation C1, C2 and substantially perpendicular to the linear axis X, (v) a second Linear drive unit 29 which is arranged on the pivot yoke 30 and by means of a second tool carriage 31 along a further linear adjusting axis Z can be moved, which is substantially perpendicular to the pivot axis B, and finally (vi) two of the above-mentioned devices 10th

As follows, in particular with reference to Fig. 6 to 9 will be explained in more detail, each of the devices 10 comprises generally (a) a spindle shaft 32 having a tool receiving portion 34 and in a spindle housing 36 about a tool axis of rotation A1, A2 (A from Fig. 6 ) is rotatably mounted, and (b) an electric rotary drive 38 (see Fig. 8 ), which has a rotor 40 and a stator 42 and by means of which the spindle shaft 32 operatively connected to the rotor 40 can be driven to rotate about the tool rotation axis A1, A2 (A). Significant features of the device 10 in this case are that the rotor 40 and the stator 42 of the electric rotary drive 38 and the spindle shaft 32 are arranged to save space coaxially in the spindle housing 36, which in turn in a guide tube 44 in the direction of the tool axis of rotation A1, A2 (A ) is axially displaceably guided (linear adjusting axis Z) is guided, wherein the spindle shaft 32 is formed as a hollow shaft, via which for receiving a membrane chuck tool 46 running tool receiving portion 34 can be acted upon with a fluid - as will also be described in more detail below - so that, for example, a polishing plate 47 accommodated on the membrane chuck tool 46 rapidly removes relatively small axial compensatory movements (linear movements Z'1, Z'2 or linear movement Z ') Fig. 6 ).

According to the Fig. 1 to 5 the devices 10 are now flanged with their respective spindle housing 36 on the second tool slide 31 of the polishing machine 12 and attached with their respective guide tube 44 to the pivot yoke 30 of the polishing machine 12 that they associated with their tool receiving portions 34 each one of the workpiece spindles 20 in the working space 14 protrude. In this case, the tool rotation axis A1, A2 of each device 10 forms with the workpiece rotation axis C1, C2 of the associated workpiece spindle 20 an imaginary plane (perpendicular to the plane of the drawing Fig. 4 and parallel to the plane of the drawing Fig. 5 ), in which the respective tool axis of rotation A1, A2 with respect to the workpiece axis of rotation C1, C2 of the associated workpiece spindle 20 axially displaceable (linear axis X, linear adjustment axis Z) and tiltable (pivoting adjustment axis B). The tool receiving portion 34 of the spindle shaft 32 is in Fig. 5 can not be seen, because the membrane chuck tool 46 is received on the tool receiving portion 34, as well as the Fig. 6 to 9 illustrate.

This according to in particular the Fig. 2 machine housing 16 mounted obliquely on the machine frame 18 is designed as a welded sheet-metal housing, comprising a bottom plate 48, a cover plate 50, two side walls 52, a rear wall 56 bevelled to a drain 54 provided in the bottom plate 48, and a front wall 58 which in total comprises the working space 14 limit. While the side walls 52 and the front wall 58 are provided with windows 60, in the bottom plate 48 there are round recesses (not shown) for passing the workpiece spindles 20 and a drive shaft 61 of the rotary drive 22 and elongated recesses 62 in the cover plate 50 (see FIGS Fig. 2 to 4 ) are provided for the passage of the devices 10 in the working space 14. The elongated recesses 62 also allow for an axial back and forth movement of the devices 10 in the direction of the linear axis X, ie in the direction of the front wall 58 and away therefrom, wherein for sealing against the working space 14 in the illustrated embodiment, in each case a bellows cover comprising a sliding plate 63 64 is provided as a flexible work space cover. In this case, a hole in the respective sliding plate 63 is penetrated by the guide tube 44 of the respective device 10, wherein a rolling bellows 65 provides for a tiltable seal between the guide tube 44 and the sliding plate 63.

As in particular in the Fig. 4 and 5 can be clearly seen, the workpiece spindles 20 are flanged in the working space 14 from above on the bottom plate 48 and pass through this each with a drive shaft 66 and an actuating mechanism 68 for a collet 70, by means of which a lens L locked on a block piece S can be tensioned axially fixed and capable of rotation on the respective workpiece spindle 20 (cf. Fig. 5 and 9 ). With 72 fortified pneumatic cylinders of the actuating mechanisms 68 are numbered below the bottom plate 48, by means of which the collets 70 can be opened or closed in a known per se. Behind the rear wall 56, ie outside the working space 14 of the rotary drive 22 - in the illustrated embodiment, a speed-controlled asynchronous three-phase motor - also flanged from above on the bottom plate 48. Below the bottom plate 48 pulleys 74 are further attached to the drive shafts 61, 66 of rotary drive 22 and workpiece spindles 20 and operatively connected by means of a V-belt 76, so that the rotary drive 22 at the same time both workpiece spindles 20 with a predetermined rotational speed can drive (workpiece axes of rotation C1, C2 or C).

How best in the Fig. 2 to 4 can be seen, the first linear drive unit 24 in the illustrated embodiment comprises a driven by a servo motor 78 via a clutch ball screw 80 which is received in a mounted on top of the cover plate 50 guide box 82 on which the first tool carriage 26 is guided. This substantially horizontally extending linear axis X is CNC-position-controlled; however, to simplify the illustration, the associated displacement measuring system is not shown.

According to the Fig. 1 to 4 is the substantially U-shaped pivot yoke 30 with his legs on in the Fig. 1 and 2 hinged front end of the first tool carriage 26 so that it can pivot about the pivoting adjustment axis B. At the in Fig. 2 rear or in Fig. 5 right end of the first tool carriage 26, the pivot drive unit 28 is articulated, so that it can pivot about an axis 84. In the illustrated embodiment, the swivel drive unit 28 is a commercially available linear module, as can be obtained, for example, from the company SKF under the name "lifting cylinder CARE 33". These linear modules, which are used in large numbers, for example as automatic window openers or for the adjustment of hospital beds, have a lifting rod 86, which can be extended or retracted via a spindle drive (not shown in detail) driven by a DC motor 88. Here, the self-locking of the spindle drive is so large that the lifting rod 86 remains in its once approached position even under greater axial loads when the DC motor 88 is turned off without it od a brake or the like. The lifting rod 86 of the rotary drive unit 28 is now facing away from the DC motor 88 end in a middle, in the Fig. 1 to 4 hinged upper portion of the U-shaped pivot yoke 30, so that the lifting rod 86 relative to the pivot yoke 30 about a further axis 90 (see Fig. 1 and 2 ) can pivot. In that regard, it can be seen that in the case of the articulated chain formed as described above, a defined axial extension or retraction of the lifting rod 86 results in the pivot yoke 30 being pivoted in a defined manner about the pivoting adjusting axis B.

Furthermore, in particular the Fig. 1 to 3 show on both sides of the pivot yoke 30 on the pivot drive unit 28 facing end linear guide carriage 92 is mounted, which cooperate with respective associated linear guide rails 94, which in turn mounted on both sides of the substantially V-shaped second tool carriage 31 on its side facing away from the pivot drive unit 28 end side are. At the in the Fig. 1 to 5 upper end of the second tool carriage 31, a holder 96 for the second linear drive unit 29 is attached. In the second linear drive unit 29 is in the illustrated embodiment - As in the swivel drive unit 28 - also a commercially available linear module, with a lifting rod 86 ', which via a DC motor 88' driven spindle drive (not shown) off or can be retracted. The lifting rod 86 'of the second linear drive unit 29 is now articulated with its end facing away from the DC motor 88' to two counter-holders 98, which in turn are attached to a central region of the U-shaped pivot yoke 30. In that regard, it can be seen that an axial extension or retraction of the lifting rod 86 'causes the second tool slide 31 is guided on the pivot yoke 30 is guided relative to the pivot yoke 30 axially displaced upwards or downwards, along the linear adjusting axis Z ,

According to the particular Fig. 2 and 3 Finally, the second tool carriage 31 has on both sides in each case a side wall 100 to which the spindle housing 36 of the respective device 10 is flanged. Furthermore, on both sides of the pivot yoke 30 near the pivoting adjusting axis B, a mounting bracket 102 is mounted on the pivot yoke 30, on which the guide tube 44 of the respective device 10 is mounted, as will be described in more detail below.

As far as the possibilities of movement of the membrane chuck tool 46 held on the device 10 are concerned, it should be noted at this point that the electric rotary drive 38 of the device 10-in the illustrated exemplary embodiment a synchronous three-phase motor-is speed-controlled (tool axes of rotation A1, A2 or A) ). By contrast, the linear movement of the membrane chuck tool 46 held in the direction Z by means of the second linear drive unit 29 via the second tool carriage 31 is an adjusting movement. This movement possibility is primarily used to (1) to position the membrane chuck tool 46 before the actual polishing process relative to the lens L (linear adjustment axis Z), whereupon the polishing plate 47 mounted on the membrane chuck tool 46 is brought into contact with the spectacle lens L by pressurizing the membrane chuck tool 46 via the hollow spindle shaft 32 (linear movements Z'1, Z'2 in FIG Fig. 5 or Z 'from Fig. 6 ) and during the polishing operation with a predetermined force in the direction of the lens L is pressed to produce a polishing pressure, and (2) the membrane chuck tool 46 after the polishing process again lift off the lens L.

Accordingly, the above-described polishing machine 12 allows, for example, the following procedure, which should be described only for a lens L, because the second lens L of the respective "RX job" in an analogous manner and at the same time polished. After loading the polishing machine 12 with the membrane chuck tools 46 and polishing plates 47 and the lenses to be processed L is first by means of the pivot drive unit 28, the angle of rotation of the tool axes of rotation A1, A2 and A with respect to the workpiece axes of rotation C1, C2 and C depending on the geometry to be machined on the lens L set to a predetermined angle value (pivot axis B). This angle of attack is not changed during the actual polishing. Then, the membrane chuck tool 46 is moved by means of the first linear drive unit 24 in a position in which it is opposite the lens L (linear axis X). Thereafter, the membrane chuck tool 46 is displaced axially by means of the second linear drive unit 29 in the direction of the lens L and positioned (linear control axis Z), whereupon the polishing plate 47 comes into contact with the lens L through pressurization of the membrane chuck tool 46 via the hollow spindle shaft 32 (linear movement Z'1, Z'2 and Z '). Now, the polishing agent supply is turned on, and the membrane chuck tool 46 with the polishing plate 47 and the lens L are rotated by means of the electric rotary drive 38 and the rotary drive 22 (tool axes of rotation A1, A2 and A, workpiece axes of rotation C1, C2 or C). Preferably, a synchronous synchronization takes place between the tool and the workpiece; However, it is also possible to drive tool and workpiece in opposite directions and / or to rotate at different speeds. Now the membrane feed tool 46 is oscillated by means of the first linear drive unit 24 with relatively small strokes over the spectacle lens L (linear axis X), so that the polishing plate 47 is guided over different surface regions of the spectacle lens L. Here, the polishing plate 47 of the (non-circular) geometry on the polished spectacle lens L also moves slightly up and down (linear movement Z'1, Z'2 and Z '). Finally, after switching off the polishing agent supply and stopping the rotational movements of the tool and workpiece (tool axes of rotation A1, A2 or A, workpiece axes of rotation C1, C2 and C, respectively) and depressurizing the membrane lining tool 46 via the hollow spindle shaft 32 by means of the membrane chuck tool 46 second linear drive unit 29 lifted away from the lens L (linear adjustment axis Z). Finally, the membrane chuck tool 46 is moved by means of the first linear drive unit 24 into a position (linear axis X) which allows the lens L to be removed from the polishing machine 12 or the membrane chuck tool 46 and / or the polishing plate 47 to be changed.

Although the movements in B and Z have been described above as pure positioning movements, which serve to position the respective membrane chuck tool 46 angularly or in the axial direction relative to the associated workpiece spindle 20 before the actual polishing processing, the drive units (pivot drive unit 28, second Linear drive unit 29) of course, the respective membrane chuck tool 46, of course, during the actual polishing, for example, continuously process, if necessary or desired. The following are with reference to the Fig. 6 to 9 Structure and function of the device 10 described in more detail.

According to the particular Fig. 8 and 9 the spindle housing 36 is made of several parts, with a by means of a cover 104 in Fig. 8 upwardly closed, substantially cube-shaped motor housing 106 in which the rotor 40 and the stator 42 of the electric rotary drive 38 are arranged, and a sleeve-like shaft housing 108 flanged thereto, in which the spindle shaft 32 is rotatably supported via two bearings 110. With the in the 6 and 7 rear or in Fig. 8 right side wall 112, the motor housing 106 is flanged to the side wall 100 of the second tool carriage 31 with the aid of screws (not shown), as the Fig. 2 and 3 reveal. On the in the 6 and 7 front or in Fig. 8 left side wall 114 of the motor housing 106, a plug-in connection 116 for the electrical supply of the rotary drive 38 and associated signal / sensor cable is provided.

In the lower part of the Fig. 6 to 8 is the hollow cylindrical guide tube 44 can be seen, which is connected at its upper end in these figures with a through hole having mounting plate 118, for example via an adhesive and / or clamping connection, which in turn means of in the Fig. 6 and 8th shown bolts 120 is screwed from above on the associated mounting bracket 102 on the pivot yoke 30 of the polishing machine 12 to secure the guide tube 44 on the pivot yoke 30, as in the Fig. 1 . 2 . 4 and 5 shown.

Near the in the Fig. 8 and 9 lower end of the guide tube 44, a sliding or guide ring 124 is inserted in plastic in an inner peripheral side provided radial groove 122 of the guide tube 44, which cooperates with a cylindrical outer peripheral surface 126 of the shaft housing 108 to the spindle housing 36 in the guide tube 44 largely radially play freely axially.

On the in the Fig. 8 and 9 lower end of the extending through the guide tube 44 therethrough shaft housing 108, a ring member 128 is pushed, which by means of grub screws 130 ( Fig. 8 ) is clamped to the outer peripheral surface 126 of the shaft housing 108 with an O-ring 132 sealing between the outer peripheral surface 126 of the shaft housing 108 and the inner peripheral surface of the annular member 128. Furthermore, between the remote from the rotary drive 38, ie in the Fig. 8 and 9 lower end of the guide tube 44 and the remote from the rotary drive 38, ie in the Fig. 8 and 9 arranged at the lower end of the shaft housing 108, a bellows 134 which surrounds the shaft housing 108 of the spindle housing 36. Here, the bellows 134 is fixed at its axial ends in each case by means of a clamping ring 136 and a clamping collar on the outer peripheral surface of the guide tube 44 and the ring member 128.

On the side facing away from the rotary drive 38, ie in the Fig. 8 and 9 The lower end of the spindle shaft 32 extending through the shaft housing 108 furthermore has a centrifugal disk 138 acting as a centrifugal seal for the liquid polishing agent, likewise by clamping by means of grub screws 140 (FIG. Fig. 6 to 8 ). In this case, the centrifugal disc 138 holds on the inner peripheral side a radial sealing ring 142, which is provided with an annular end surface 144 (FIG. Fig. 9 ) of the shaft housing 108 and the inner peripheral surface of the ring member 128 sealingly cooperates, and also forms with a sloping end face 146 of the ring member 128 a small gap 148, as well as the Fig. 9 can be seen.

Inside the motor housing 106, the stator 42 of the electric rotary drive 38, whose windings in Fig. 8 are indicated, with the motor housing 106 shed. The electric Rotary drive 38, which has a large, continuously controllable speed range, is air-cooled and has for this purpose in the upper region of the rotor 40, a fan (not shown). At her in Fig. 8 upper, projecting into the motor housing 106 end carries the spindle shaft 32, the rotor 40, which is rotatably connected there in a suitable manner, for example by means of a ring-clamping element 150 or other known shaft-hub connection with the spindle shaft 32. The associated clamping screws 152 serve at the same time the attachment of the fan (not shown).

In Fig. 8 Above the spindle shaft 32, the cover 104 of the motor housing 106 is provided with a central through-bore 154 in which a commercially available rotary feedthrough 156 (rotary plug) for the fluid or pressure medium is attached to the membrane lining tool 46, which is in fluid communication with the hollow spindle shaft 32 , Here, the rotary feedthrough 156 is frictionally fixed in the through hole 154 of the lid 104 by means of a commercially available elastic cable grommet 158.

The spindle shaft 32 has a continuous stepped bore 160 with three cylindrical bore portions 162, 164, 166, which in Fig. 8 increase in diameter from top to bottom. In the upper bore portion 162, the rotary feedthrough 156 is inserted. The central bore portion 164, which extends axially between the bearings 110 of the spindle shaft 32 in the axial direction, connects the upper bore portion 162 to the lower bore portion 166. The lower bore portion 166 eventually forms the tool receiving portion 34 for the membrane chuck tool 46 and is provided with a Radial groove 168 provided for receiving an O-ring 170, which ensures a seal between the spindle shaft 32 and diaphragm chuck tool 46.

In the Fig. 6 to 9 Finally, this is also the tool receiving portion 34 of the spindle shaft 32 by means of a grub screw 172 ( Fig. 8 ) held membrane feed tool 46 exemplified. This can in principle correspond to the polishing tools described in the already mentioned publications EP-A-1 473 116 . EP-A-1 698 432 and EP-A-2 014 412 are expressly referred to at this point in terms of structure and function of such membrane feed tools 46.

In the present case, an actively driven spindle shaft 32, however, the rotational drive in the diaphragm chuck tool 46 is realized differently, not via the bellows 174 of the diaphragm chuck tool 46, but over the axially displaceable in the diaphragm chuck tool 46 guide member 176. Here, the guide member 176 is supported on his in the Fig. 8 and 9 upper end via a transverse pin 178 on two longitudinal pins 180 from which are attached to the main body 182 of the membrane chuck tool 46. At his in the Fig. 8 and 9 lower ball end 184 is also a transverse pin 186 is provided with associated recesses 188 (FIG. Fig. 9 ) engages the ball head bearing 190. Finally, the polishing plate 47 is replaceably held on the membrane feed tool 46 via an interface 192. Such polishing plates 47 are for example the publication DE-A-10 2007 026 841 refer to; the interface 192 essentially corresponds to that in the DE-A-10 2009 036 981 illustrated and described interface. In this respect, reference should be made at this point to the cited documents.

When the present document generally refers to "fluid", it is intended to include gases, such as e.g. Compressed air, or liquids, such as oil, are understood, which can be used as a pressure medium.

It is a device for fine machining of optically active surfaces in particular eyeglass lenses disclosed with a spindle shaft having a tool receiving portion, which is rotatably mounted in a spindle housing about a tool axis of rotation, and a rotary electric motor having a rotor and a stator, by means of which the spindle shaft operatively connected to the rotor is rotatably driven about the tool rotation axis, while the tool receiving portion in the direction of the tool axis of rotation is axially displaceable. A special feature of this device is that rotor and stator and the spindle shaft are arranged coaxially in the spindle housing, which in turn is guided axially displaceably defined in a guide tube in the direction of the tool rotation axis, wherein the spindle shaft is formed as a hollow shaft, via which for receiving a tool receiving portion running a membrane chuck tool can be acted upon with a fluid, which in particular requires a very compact design and allows rapid axial compensating movements of the tool during fine machining.

LIST OF REFERENCE NUMBERS

10

contraption

12

polisher

14

working space

16

machine housing

18

machine frame

20

Workpiece spindle

22

rotary drive

24

first linear drive unit

26

first tool slide

28

Swivel drive unit

29

second linear drive unit

30

pivot yoke

31

second tool carriage

32

spindle shaft

34

Tool receiving portion

36

spindle housing

38

electric rotary drive

40

rotor

42

stator

44

guide tube

46

Membrane lining tool

47

polishing plate

48

baseplate

50

cover plate

52

Side wall

54

outflow

56

rear wall

58

front wall

60

window

61

drive shaft

62

recess

63

sliding plate

64

Bellows cover

65

bellows

66

drive shaft

68

actuating mechanism

70

collet

72

pneumatic cylinder

74

pulley

76

fan belt

78

servomotor

80

Ball Screw

82

guide box

84

axis

86, 86 '

lifting rod

88, 88 '

DC motor

90

axis

92

Linear guide carriage

94

Linear guide rail

96

holder

98

backstop

100

side cheek

102

mounting bracket

104

cover

106

motor housing

108

shaft housing

110

camp

112

Side wall

114

Side wall

116

plug-in connection

118

mounting plate

120

screw

122

radial groove

124

sliding ring

126

Outer circumferential surface

128

ring part

130

grub screw

132

O-ring

134

bellow

136

clamping ring

138

slinger

140

grub screw

142

Radial seal

144

face

146

face

148

gap

150

Ring clamping element

152

clamping screw

154

Through Hole

156

Rotary union

158

cable grommet

160

stepped bore

162

bore section

164

bore section

166

bore section

168

radial groove

170

O-ring

172

grub screw

174

bellow

176

guide member

178

cross pin

180

longitudinal pin

182

body

184

Ball head end

186

cross pin

188

recess

190

Ball head bearing

192

interface

A

Tool rotation axis in general (speed-controlled)

A1

Rotary axis right tool (speed-controlled)

A2

Rotary axle left tool (speed-controlled)

B

Pivoting axis tool

C

Workpiece rotation axis in general (speed-controlled)

C1

Rotary axis right workpiece (speed controlled)

C2

Rotary axis left workpiece (speed-controlled)

cc

second optically effective surface

cx

first optically effective surface

L

lens

M

block material

S

block piece

X

Linear axis of the first tool carriage (position-controlled)

Z

Linear positioning axis second tool carriage

Z '

Linear motion tool general (uncontrolled)

Z'1

Linear motion right tool (uncontrolled)

Z'2

Linear motion left tool (uncontrolled)

Claims (10)

1. Device (10) for fine processing of optically active surfaces (cc, cx) at, in particular, spectacle lenses (L), comprising a spindle shaft (32), which has a tool mounting section (34) and which is mounted in a spindle housing (36) to be rotatable about an tool axis of rotation (A), and an electric rotary drive (38), which comprises a rotor (40) and a stator (42) and by which the spindle shaft (32) operatively connected with the rotor (40) is drivable to rotate about the tool axis of rotation (A), whilst the tool mounting section (34) is axially displaceable in the direction of the tool axis of rotation (A), characterized in that the rotor (40) and the stator (42) of the electric rotary drive (38) and the spindle shaft (32) are coaxially arranged in the spindle housing (36), which in turn is guided in a guide tube (44) to be capable of defined axial displacement (linear setting axis Z) in the direction of the tool axis of rotation (A), wherein the spindle shaft (32) is constructed as a hollow shaft by way of which the tool mounting section (34) constructed for mounting a diaphragm chuck tool (46) can be acted on by a fluid.
2. Device (10) according to claim 1, characterized in that the spindle housing (36) comprises a motor housing (106), in which the rotor (40) and the stator (42) of the rotary drive (38) are arranged, and a shaft housing (108), which is flange-mounted thereon and in which the spindle shaft (32) is rotatably mounted.
3. Device (10) according to claim 2, characterized in that the motor housing (106) is closed by a cover (104) having a passage bore (154) in which a rotary leadthrough (156) for the fluid is fastened, the leadthrough being in fluid connection with the hollow spindle shaft (32).
4. Device (10) according to claim 3, characterized in that the rotary leadthrough (156) is frictionally fixed in the passage bore (154) of the cover (104) by a resilient cable leadthrough bush (158).
5. Device (10) according to any one of the preceding claims, characterized in that a bellows (134) surrounding the spindle housing (36) is arranged between the end of the guide tube (44) facing away from the rotary drive (38) and the end of the spindle housing (36) remote from the rotary drive (38).
6. Device (10) according to any one of the preceding claims, characterized in that a centrifuging disc (138) for a liquid fine processing medium is mounted on the end of the spindle shaft (32) facing away from the rotary drive (38).
7. Device (10) according to any one of the preceding claims, characterized in that the spindle housing (36) is axially guided in the guide tube (44) by a slide ring (124).
8. Polishing machine (12) for simultaneous polishing of two spectacle lenses (L), comprising
   a machine housing (16) bounding a work space (14),
   two workpiece spindles (20), which project into the work space (14) and by way of which two spectacle lenses (L) to be polished are drivable to rotate about substantially mutually parallelly extending workpiece axes of rotation (C1, C2) by a common rotary drive (22),
   a first linear drive unit (24), by which a first tool carriage (26) is movable along a linear axis (X) extending substantially perpendicularly to the workpiece axes of rotation (C1, C2),
   a pivot drive unit (28), which is arranged on the first tool carriage (26) and by which a pivot yoke (30) is pivotable about a pivot setting axis (B) extending substantially perpendicularly to the workpiece axes of rotation (C1, C2) and substantially perpendicularly to the linear axis (X),
   a second linear drive unit (29), which is arranged on the pivot yoke (30) and by which the at least one second tool carriage (31) is movable along a linear setting axis (Z) extending substantially perpendicularly to the pivot setting axis (B), and
   two devices (10) according to any one of the preceding claims, which project into the work space (14) by their tool mounting sections (34) each associated with a respective one of the workpiece spindles (20), the respective spindle housing (36) of which is flange-mounted on the at least one second tool carriage (31), whilst the respective guide tube (44) is mounted on the pivot yoke (30), so that the tool axis of rotation (A1, A2) of each device (10) forms together with the workpiece axis of rotation (C1, C2) of the associated workpiece spindle (20) a plane in which the respective tool axis of rotation (A1, A2) is axially displaceable (linear axis X, linear setting axis Z) and tiltable (pivot setting axis B) with respect to the workpiece axis of rotation (C1, C2) of the associated workpiece spindle (20).
9. Polishing machine (12) according to claim 8, wherein only one second tool carriage (31) is provided for the common axial movement (linear setting axis Z) of the two spindle housings (36) by the second linear drive unit (29).
10. Polishing machine (12) according to claim 8 or 9, wherein each of the pivot drive unit (28) and the second linear drive unit (29) is a proprietary linear module with a stroke rod (86, 86') movable in and out by way of a spindle drive driven by a direct-current motor (88, 88').

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