HK1203891B - Device for fine machining of optically effective surfaces on in particular spectacle lenses and flexible production cell comprising such a device - Google Patents

Description

Device for finishing an optically active surface, in particular on an ophthalmic lens, and flexible production unit comprising such a device

Technical Field

The present invention relates in general to a device for finishing an optically active surface according to the preamble of claim 1. In particular, the invention relates to a device for finishing the optically active surface of an ophthalmic lens, such as for a so-called "RX plant", i.e. a production facility for the mass production of individual ophthalmic lenses from optometry results. In addition, the invention relates to a flexible production unit for processing an ophthalmic lens, comprising such a finishing device.

Background

Machining the optically active surface of an ophthalmic lens by machining can be roughly divided into two machining stages, i.e. first, the optical surface is preliminarily machined to make a macroscopic geometry according to the result of optometry, and then the optically active surface is machined to a final state to eliminate the traces of preliminary machining and to obtain the desired microscopic geometry. Whereas, depending in particular on the material of the ophthalmic lens, the optically active surface of the ophthalmic lens is subjected to a preliminary machining by grinding (in the case of mineral glass), milling and/or turning (in the case of synthetic materials such as polycarbonate, CR39 (colombia resin No. 39), HI Index (high definition ultra thin material)) and, for finishing, the optically active surface of the ophthalmic lens is usually subjected to a finishing, grinding and/or polishing treatment, for which purpose a corresponding machining device is required.

First of all, the polishing machines manually loaded in the RX plant are generally configured as "twin machines" in this case, so that advantageously two ophthalmic lenses of the "RX work", the ophthalmic lens prescription always comprising a pair of ophthalmic lenses, can be processed simultaneously. Such "twin" polishing machines are known, for example, from patent document US-A-2007/0155287, which defines the preamble of claim 1.

In the previously known polishing machines, two parallel workpiece spindles, which project from below into a working space where two polishing tools are opposite the workpiece spindles, so that one polishing tool is associated with one workpiece spindle and the other polishing tool is associated with the other workpiece spindle, are each driven in rotation about an axis of rotation, but are otherwise stationary. Each burnishing tool is mounted for free rotation by a spherical bearing on a piston rod of each associated piston-cylinder arrangement, which spherical piston rod projects into the working space from above, which piston-cylinder arrangement is arranged above the working space, and by which each burnishing tool can be lowered or raised independently with respect to the associated workpiece spindle. In addition, the two piston-cylinder arrangements can usually be moved upwards and backwards by means of a linear drive in a direction perpendicular to the axis of rotation of the workpiece spindle relative to the front side of the polishing machine, and the two piston-cylinder arrangements can usually be tilted by means of a pivoting drive about a pivot axis, which similarly extends perpendicular to the axis of rotation of the workpiece spindle and parallel to the front side of the polishing machine. By means of the pivot drive, the angular position between the tool and the axis of rotation of the workpiece can be set before the tool is lowered onto the workpiece by means of the piston-cylinder arrangement. During the actual polishing process, the workpiece is driven in rotation, in which case the tool arranged to cooperate with the workpiece machining is brought in rotation by friction, while the linear drive ensures that the tool travels alternatively back and forth (oscillating movement) relative to the front side of the polishing machine, wherein the tool running on a relatively small path moves back and forth on the tool (becomes "tangential movement"). In addition, linear drives are used to move the tool and workpiece apart to the extent that they can be replaced.

Although the above known polishing machine also has a very small construction, it requires a relatively large coverage area in the depth direction due to the long horizontal travel path of the piston-cylinder arrangement perpendicular to the workpiece spindle rotation axis, which conflicts with, for example, a flexible production unit for ophthalmic lens processing in a small RX plant. In addition, the accessibility of the polishing machine, in particular for changing workpieces and tools and for cleaning the working space, is not optimal.

Disclosure of Invention

Object of the Invention

The object of the present invention is to produce a device for finishing the optically active surface of in particular ophthalmic lenses which requires a relatively small footprint, enables integration as a module in a flexible production unit for ophthalmic lens machining without problems, and which, as stated in the introduction, is moreover more ergonomically designed than the prior art in terms of workpiece and tool replacement and maintenance and cleaning operations. The object of the invention also consists in providing a flexible production unit, which is constructed in a manner as economical as possible, for the preliminary machining and finishing of ophthalmic lenses.

This object is achieved by the features of claims 1 to 15. Advantageous or suitable developments of the invention are the subject matter of claims 2 to 14.

According to the invention, in a device for optionally finishing an optically effective surface, in particular an ophthalmic lens, as a workpiece, the device comprises: at least one workpiece spindle which projects into the working space and by means of which a workpiece to be machined can be driven in rotation about a workpiece rotation axis; at least one feed device for the tool, by means of which the tool can be moved towards the workpiece or away from the workpiece; a swing drive unit by means of which the feed device can be reciprocated in a swing direction which extends transversely to the workpiece rotation axis during machining; and a pivot drive unit, by means of which the feed device can be pivoted about a pivot adjustment axis which extends in a direction substantially perpendicular to the workpiece rotation axis and substantially normal to the swivel direction, a pivot mechanism being provided, by means of which the feed device, the swivel drive unit and the pivot drive unit can be pivoted relative to the workpiece spindle from a relatively closed position to a relatively open position in order to open the working space in the case of an opening of the working space, and can be pivoted in the opposite direction.

In other words, with the pivoting mechanism according to the invention, the main part of the device, which comprises the feed device, the swing drive unit and the pivot drive unit and is located on the tool side, can be pivoted towards and away from each other and can be pivoted in the opposite direction relative to the main part of the device, which comprises the workpiece spindle and is located on the workpiece side, or in an alternative example, the main part of the device, which is located on the workpiece side, can be pivoted towards and away from each other and can be pivoted in the opposite direction relative to the main part of the device, which is located on the tool side, or in another example, the two main parts of the device can be pivoted towards and away from each other and can be pivoted in the opposite direction.

In particular, the travel path of the oscillating drive unit can thereby be greatly shortened compared to the prior art described above, without hindering workpiece or tool changes, so that the device according to the invention has a substantially more compact structure and requires less footprint. The workpiece replacement and the tool replacement, as in the case of the maintenance and cleaning operations at the device, are also simplified in comparison with the prior art described in the introduction, since the pivoting according to the invention with the open working space releases a greatly increased open cross section, through which an operating gripper and/or an optional automatic gripping device, cleaning tool or the like can enter the device or gain access to the device without problems. In addition, the pivoting according to the invention can advantageously be such that in this respect there is a "turning" angle of the respective pivoting main part of the device towards the released open cross section, so that it is possible to grip the tool or workpiece not only from the side but also from the front and thus more safely. The device according to the invention thus not only has a relatively small space requirement, but also has good working space accessibility and is therefore an ergonomically highly suitable design which overall makes the device particularly suitable for flexible production units.

It should be additionally explained that the kinematic design of the device can in principle be such that, in the case of the prior art category, in particular with an oscillating drive mechanism, the oscillating drive unit can move the feed device to and fro in an axial direction substantially perpendicular to the workpiece rotation axis and in particular back and forth relative to the operator position or front side of the device during the machining process. However, the swinging movement can also be carried out in the same way in the longitudinal direction of the front side of the device or substantially parallel to the front side of the device, and/or by a pivoting movement instead of an axial movement. The use of the pivoting mechanism according to the invention is independent.

In principle, it is conceivable to provide independent pivoting of the feed device, the wobble drive unit and/or the pivot drive unit relative to the workpiece spindle, in given cases even about different pivot axes, to open up the working space, however, in view of the ease of operation and low mechanical outlay, it is preferred that the pivot mechanism has a common pivot axis for the feed device, the wobble drive unit and the pivot drive unit, about which the feed device, the wobble drive unit and the pivot drive unit can be pivoted jointly away from the workpiece spindle or close to the workpiece spindle.

Further, it is preferred that the pivot axis is located behind the workspace as seen from the operator position. This preferred solution has the advantage that, in comparison to a similar possible arrangement of the pivot axis to the right or left of the workspace as seen from the operator position, a symmetrical, hands-free work is possible, so that the device can be used equally well by right-handed and left-handed persons.

In addition, for a structurally small and mechanically simple device design, it is preferred that the pivot axis of the pivoting mechanism extends substantially parallel to the pivot adjustment axis of the pivot drive unit.

Advantageously, the pivoting mechanism may comprise a pivoting carriage having a gripping section by means of which the feed device, the swing drive unit and the pivoting drive unit can be manually pivoted away from and close to the workpiece spindle. This represents a simple and economical alternative to the equally possible fully automatic or motor-assisted pivoting movement, which also requires suitable safety precautions (protection system, protection means). In a preferred embodiment, the pivot carriage also carries a shroud to open or close the device. This structure additionally simplifies the handling of the device compared to a shield independent of the pivoting mechanism, which is also contemplated.

In addition, the pivoting mechanism may comprise at least one spring element which facilitates the pivoting of the feeding device, the swing drive unit and the pivot drive unit away from the workpiece spindle. The at least one spring element (for example, one or more gas compression springs) can in this case be designed such that, for example, it substantially bears the weight of the part to be pivoted away, which not only ensures a high level of operational convenience but is also advantageous for operational safety.

In addition, a positioning and closing mechanism can be provided which holds the feed device, the pivoting drive unit and the pivoting drive unit in their closed position during the machining process and ensures a substantially perpendicular orientation of the presently preferred linearly extending pivoting direction relative to the workpiece rotation axis. The positioning and closing mechanism can thus counteract the machining forces caused during machining (for example by the polishing pressure exerted by the feed device) and at the same time can ensure the desired relative position of the moved parts with respect to one another, which is particularly important in the case of the polishing process mentioned in the introduction of the tangential movement for ensuring reproducible polishing results. In this respect, the positioning and closing arrangement may advantageously comprise a pressure medium cylinder, for example a gas cylinder, for holding the feed device, the swing drive unit and the pivot drive unit in the closed position, but a mechanically positive locking of the pivot mechanism may also be used. Furthermore, it is preferred that the positioning and closing structure comprises at least one adjustable abutment, optionally comprising a shock absorber, and by means of which the orientation of the direction of oscillation can be adjusted relative to the working axis of rotation. In particular, the adjustable abutment has the advantage over a fixed abutment which is possible in principle that manufacturing tolerances can be taken into account more easily, since simple compensation is possible. With the optional existing shock absorber, damage to the device can be avoided in case the workspace is closed too tightly.

In a preferred embodiment, the device further has a base body which delimits the working space and supports the workpiece spindle, to which base body two mountings carrying the pivot axis of the pivoting mechanism are fastened, wherein the swing drive unit comprises a guide block which is pivotably mounted on the pivot axis between the two mountings. Advantageously, therefore, also the components of the pendulum drive unit are used for the pivoting mechanism.

In addition, the swing driving unit may include: two guide rods supported in the guide block in a longitudinally displaceable manner; a seeker; and a guide plate, wherein the guide rods are connected together by means of a guide head on one side of the guide block and on the other side of the guide block, said guide rods are connected together by means of the guide plate, and wherein the guide head is displaceable relative to the guide block by means of a threaded drive. In this sense, the pendulum drive unit can advantageously be constructed from a dedicated linear lever guide, the sliding part of which as a guide block is pivotably fixed to the pivot axis of the pivoting mechanism, thereby having a high level of functional integration in the guide block. In this respect, for further functional integration and a reduction in the number of parts in the swiveling drive unit, it is furthermore preferred that the pivoting drive unit has a pivoting yoke which carries the feed device and is supported on a guide head of the swiveling drive unit, wherein a stroke module is arranged between the swiveling drive unit and the pivoting yoke, by means of which stroke module the pivoting yoke can be pivoted about the pivot adjustment axis.

In a further concept of the invention, for a "twin" mode machine, two workpiece spindles can be provided which protrude into the working space and can be driven in rotation about the workpiece rotation axis by a belt drive comprising a pulley driven in rotation by a rotary drive, a belt and a tensioning and return wheel for the belt, which is seated between the workpiece spindles and is mounted on the rotary drive in an offset manner from the pulley, so that the belt can also be tensioned by pivoting of the rotary drive. These measures are also advantageous for achieving a very compact design, wherein, in addition, no further components are required for tensioning the belt. Instead, the latter can be achieved by rotation or pivoting of the rotary drive only.

If the device described above is used as an individual machine, for example not in a machine combination, it is obvious that the device must have means for human-machine interaction and a suitable controller, for example a PC-based numerical control central controller, which controls the drive module and its axial drive. According to another aspect of the invention, a flexible production unit for the preliminary machining and finishing of ophthalmic lenses therefore comprises: (1) device for the preliminary machining of an optically active surface of an ophthalmic lens by milling, turning and/or grinding, with an adjustment drive axis or controlled drive axis for a workpiece and/or tool and with an associated drive module, and (2) a device for the finishing of an optically active surface of an ophthalmic lens by polishing, such as the device described above, with an adjustment drive axis or controlled drive axis for a workpiece and/or tool and with an associated drive module, and which is at least electrically and optionally also mechanically coupled as a module to the device for the preliminary machining, with the further feature that the device for the preliminary machining only has a human-machine interaction apparatus and a numerical control center controller which control the drive modules of both devices. The electrical connection between the numerical control center controller and the drive module can in this case be effected by individual wires or by a bus system. The device for finishing without devices for human-machine interaction and individual nc central controllers can thus be constructed in a very economical manner, and in particular it can be added as a module in a smaller RX plant — also subsequently (without great expense) to the device for preliminary machining in a given case.

Drawings

The invention is explained in detail below by means of preferred embodiments with reference to the attached drawings, which are partly simplified and schematic, wherein:

fig. 1 shows a perspective view of a flexible production unit for processing an ophthalmic lens, viewed obliquely from above and from the front right, the flexible production unit comprising: on the left, a device for the preliminary machining of ophthalmic lenses (also called generator) and, on the right, a device for the continuous finishing of ophthalmic lenses (polisher) coupled with the generator according to the invention, wherein, in order to show the working space of each respective machine, the pivoting door of the generator and the hood of the polisher have been pivoted upwards;

fig. 2 shows a perspective view of the polishing machine according to fig. 1, viewed obliquely from above and from the front right, which is enlarged to scale compared to fig. 1, showing the components or subassemblies of the polishing machine, wherein, for the sake of simplicity of illustration, in particular, the other parts of the hood and cover, the power supply devices (including lines, hoses and pipes), the compressed air and polishing medium, the polishing medium return device and the measuring, maintenance and safety devices have been omitted;

fig. 3 shows a perspective view of the polishing machine according to fig. 1, which corresponds substantially to fig. 2 in scale and angle of observation and simplified illustration, wherein the upper part of the polishing machine is arranged in a position pivoted away from the lower part of the polishing machine;

fig. 4 shows a perspective view of the polishing machine according to fig. 1, viewed obliquely from above and from the front left, which is enlarged to scale compared to fig. 2 and 3 and which is split off at the machine housing, wherein the tool cylinder and the associated flexible space cover located to the left in fig. 2 and 3 are omitted, in particular such that a view is shown behind which the pivot axis for the upper part of the polishing machine is arranged;

fig. 5 shows a perspective view of the polishing machine according to fig. 1, which corresponds substantially to fig. 4 in scale and angle of observation and simplified illustration, wherein the upper part of the polishing machine is arranged in a position pivoted away from the lower part of the polishing machine;

fig. 6 shows a perspective view of the polishing machine according to fig. 1, viewed obliquely from above and from the rear right, which is identical to fig. 4 and 5 in scale, wherein the polishing machine housing is omitted in comparison with that shown in fig. 2 and 3;

fig. 7 shows a perspective view of the polishing machine according to fig. 1, which corresponds substantially to fig. 6 in scale and angle of observation and simplified illustration, wherein the upper part of the polishing machine is arranged in a position pivoted away from the lower part of the polishing machine;

fig. 8 shows a perspective view of the polishing machine according to fig. 1, viewed obliquely from above and from the rear left, which is identical to fig. 6 and 7 on the scale, wherein, in comparison to what is shown in fig. 6 and 7, all drive mechanisms and associated parts for the workpiece and the tool (up to the guide block of the oscillating drive unit) are omitted, so that the pivoting mechanism for the upper part of the polishing machine can be better seen;

fig. 9 shows a perspective view of the polishing machine according to fig. 1, which corresponds substantially to fig. 8 in scale and angle of observation and simplified illustration, wherein the upper part of the polishing machine is arranged in a position pivoted away from the lower part of the polishing machine;

fig. 10 shows a partially cut-away front view of the polishing machine according to fig. 1, which is identical to fig. 6 and 7 in scale and simplified illustration.

FIG. 11 shows a partially cut-away front view of the polishing machine similar to FIG. 10 according to FIG. 1, wherein the upper part of the polishing machine is disposed in a position pivoted away from the lower part of the polishing machine;

fig. 12 shows a sectional view of the polishing machine according to fig. 1, which corresponds to the section line XII-XII in fig. 10, but is tilted by 5 ° in the drawing plane to provide a front view of the drive mechanism (belt drive) for the workpiece;

fig. 13 shows a side view of the polishing machine according to fig. 1, seen from the left side of fig. 10, wherein, similar to fig. 8 and 9 and in contrast to what is shown in fig. 6 and 7, only the pivoting yoke of the pivoting drive unit and the guide block of the oscillating drive unit with guide head, guide rod and guide plate in the drive mechanism for the workpiece and tool and associated parts in the upper part of the machine are shown;

fig. 14 shows a sectional view of the polishing machine according to fig. 1, which corresponds to the section line XIV-XIV in fig. 13, i.e. to a section through the pivot axis for the upper part of the polishing machine; and

fig. 15 shows a simplified block diagram of a numerical control machining center (CNC) architecture of the flexible production unit according to fig. 1.

Detailed Description

A flexible production unit for the preliminary machining and finishing of an ophthalmic lens L in an RX plant is generally indicated by 10 in fig. 1. In the illustrated embodiment, the flexible manufacturing unit 10 comprises means, also called a generator 12, for preliminarily machining the optically effective surfaces cc, cx (refer to fig. 10 and 11) of the ophthalmic lens L, and the flexible manufacturing unit 10 also comprises means for machining the optically effective surfaces cc, cx of the ophthalmic lens L into a final state, in the form of a polishing machine 14, which polishing machine 14 is connected to the generator 12 both mechanically and electrically as a module, as will be described in detail later. In the following, mainly explaining the construction and action of the polishing machine 14, in the embodiment shown, this polishing machine 14 is realized in a "proportional" mode construction, so that two ophthalmic lenses L can be polished simultaneously.

With regard to the generator 12, it is mentioned here only that this generator 12 can be configured as ｃA simple quick tool lathe or as ｃA combined milling/turning machine, the principle of which is known from documents EP- ｃA-1719573 and EP- ｃA-1719585, for example. In these machines, optionally, after preliminary machining of the ophthalmic lens L by milling, as described for example in document EP- ｃA-0758571, the turning tool 16 is linearly reciprocated (axis of oscillation F) by means of ｃA fast tool servo system_D) Moving or high speed dynamic rotation to produce feed motion at the turning tool 16 to machine the asymmetrically rotating ophthalmic lens surface, while the ophthalmic lens surface L is rotationally driven to produce cutting force (axis of rotation B of the tool)_D) While between the lathe tool 16 and the ophthalmic lens L transversely to the axis of oscillation F_D(Linear axis X)_D) To produce a travel from the edge of the spectacle lens to the middle of the spectacle lens or from the middle of the spectacle lens to the edge of the spectacle lens.

In particular, according to figures 2 to 7, 10 and 11, the polishing machine 14 generally comprises: (i) two workpiece spindles 20, which workpiece spindles 20 project from below into the working space 18 and by means of which workpiece spindles 20 the spectacle lens L to be machined can be driven in rotation about a workpiece rotation axis C1, C2; (ii) two feed devices 22, one for each tool W, by means of which feed devices 22 each tool W can be moved onto and away from the associated ophthalmic lens L from above (linear movements Z1, Z2); (iii) a swing drive unit 24, by means of which swing drive unit 24 the feed device 22 can be reciprocated in a swing direction (linear swing axis X), i.e. in this case forward and backward with respect to the front side of the polishing machine 14, wherein the swing axis X extends substantially transversely to the workpiece rotation axes C1, C2 during machining; and (iv) a pivoting drive unit 26, by means of which the feed device 22 can be pivoted about a pivoting adjustment axis B, which extends in a direction substantially perpendicular to the workpiece rotation axes C1, C2 and substantially normal to the oscillation axis X.

As will be described in more detail below, the polishing machine 14 additionally comprises a pivoting mechanism 28, by means of which pivoting mechanism 28 the feed device 22, the swing drive unit 24 and the pivoting drive unit 26 can be pivoted relative to the workpiece spindle 20 with the opening of the working space 18 from a relatively closed position (fig. 2, 4, 6, 8, 10 and 12 to 14) into a relatively open position (fig. 1, 3, 5, 7, 9 and 11) and from the relatively open position into the relatively closed position, i.e. according to the arrow S in fig. 4 to 9, 13 and 14. In this case, in the embodiment shown, the pivoting movement S for the feed device 22, the swing drive unit 24 and the pivot drive unit 26 takes place jointly and in particular about a pivot axis 30 (see in particular fig. 14) of the pivot mechanism 28, which pivot axis 30 is located behind the working space 18 as seen from the operator position and extends substantially parallel to the pivot adjustment axis B.

According to fig. 1 to 5, the polishing machine 14 comprises a frame 32, which frame 32 is assembled in a welded configuration made of sheet metal, and at the same time which frame 32 forms part of a machine housing in which, in addition to the drive unit and the mechanisms visible here, power supply devices, control components and the like (not shown) are accommodated. In fig. 1, the machine housing is realized with a cover 34 and a hood 36 upwards and forwards, which hood at least partially comprises "plexiglass" (PMMA, polymethylmethacrylate) and is transparent and can be pivoted in a similar manner by means of the pivot structure 28 relative to the machine frame 32. A base body 38 is inserted into the machine housing, the base body 38 similarly being joined in a welded configuration made of sheet metal, and the base body 38 delimits the working space 18, in particular in the downward direction in the figure, and supports the workpiece spindle 20. The base body 38 has a laterally inclined flange section 40, the flange section 40 resting on an associated support surface 42 of the frame 32 and being in screw connection (not shown) with the support surface 42 to secure the base body in the polishing machine 14. As shown in fig. 1, the shape of the machine housing of the polishing machine 14 is adapted to the machine housing of the generator 12 such that the flexible production unit 10 as a whole has the appearance of being "as a single casting". In this case, the frame 32 of the polisher 14 is mechanically screwed (not shown) to the machine housing of the generator 12.

Further details of the pivoting mechanism 28 can be seen in particular from fig. 8, 9, 13 and 14. Thereby, the two mounting pieces 46 are fastened from behind to the rear wall 44 of the base body 38 on the same vertical level, but horizontally spaced apart from each other. Each of the mounting members 46 has: a mounting bottom 48, by means of which mounting bottom 48 the respective mounting piece 46 is firmly screwed (not shown) to the base body 38; two mounting arms, arranged in mirror-symmetrical fashion between the two mounts, extend upwardly away from the mounting base 48, namely a shorter (meaning the central space between the two mounts 46) inner mounting arm 50 and a longer outer mounting arm 52.

In a first example, these mounts 46 support the pivot shaft 30, as can be seen in fig. 13 and 14. More precisely, according to fig. 14, two screws 54 are provided, each engaging through a through hole 56 formed in each inner mounting arm 50 near the mounting base 48, and being screwed into an associated threaded hole 58 of the pivot shaft 30 to fix the pivot shaft 30 between the two mounting pieces 46, wherein the threaded holes 58 are formed on the front side. The guide block 60 of the swing drive unit is pivotably mounted on the pivot shaft 30 between the two mounts 46 by means of two bearing elements 62, the bearing elements 62 being mounted in a stepped through hole 64 in the guide block 60, the through hole 64 extending through the pivot shaft 30.

In addition, the pivoting mechanism 28 in the illustrated embodiment includes two spring elements, here gas compression springs 66, the springs 66 facilitating the pivoting movement of the upper body portion of the polishing machine 14, which includes the feed device 22, the swing drive unit 24 and the pivot drive unit 26, and which is located on the tool side, relative to the workpiece spindle 20. For this purpose, the gas compression springs 66 are each hinged at one end to the outer mounting arm 52 of the respective associated mounting 46, as can best be seen in fig. 8 to 10 and 14. The other end of each respective mounting member 46 is hinged to a respective associated lower projection 68 of the guide block 60 of the swing drive unit 24. In this case, the spring force of the gas compression spring 66 and the hinge point thereof determining the lever arm about the pivot axis 30 are selected such that the torque generated by the weight of the pivoting part or subassembly about the pivot axis 30 is largely cancelled out.

Further associated with the pivoting mechanism 28 is a positioning and closing mechanism 70, which positioning and closing mechanism 70 holds the upper body part with the feed device 22, the swing drive unit 24 and the pivoting drive unit 26 at the tool side in a closed position during machining and ensures a substantially perpendicular orientation of the swing axis X relative to the workpiece rotation axes C1, C2. In a first example, the positioning and closing mechanism 70 comprises a pressure medium cylinder, more precisely a gas cylinder 72, for holding those parts which are pivotable about the pivot axis 30 in their closed position, which gas cylinder comprises a cylinder housing 74 and a piston rod 76, which piston rod 76 is connected with the piston of the gas cylinder 72 and extends out of the cylinder housing 74. In this case, the cylinder housing 74 of the air cylinder 72 is pivotably connected to a bracket 78, which bracket 78 is in turn fastened to the mounting base 48 of the mounting 46 on the left in fig. 6 to 9, in particular by means of screws (not shown here). On the other hand, the piston rod 76 of the air cylinder 72 is pivotably connected to the lower projection 68 of the guide block 60, the lower projection 68 being located on the left in fig. 8 and 9. In particular, it is evident from fig. 8 and 13 that in the case of the pressure-loaded cylinder 72, the piston rod 76 thus strives to move out of the cylinder housing 74, when in the closed position of the components and subassemblies pivotable by means of the pivot mechanism 38, a torque about the pivot axis 30 (in the clockwise direction in fig. 13) is generated which pushes the components and subassemblies in the direction of the workpiece spindle 20.

In the embodiment shown, the positioning and closing mechanism 70 additionally comprises two abutments 80 of adjustable length, each of which comprises a shock absorber 82 (in the simplest form, for example, a rubber buffer) and serves to adjust the orientation of the axis of oscillation X with respect to the workpiece rotation axes C1, C2 in the closed position, which abutments may have, for example, a thread (not shown) cooperating with a mating thread for this purpose. As can be best seen in fig. 8 and 9, an adjustable abutment 80 with a respective shock absorber 82 is mounted at the free end of the inner mounting arm 50 of the mounting member 46, and in particular, such that each shock absorber 82 in the closed position can contact an associated abutment surface 84, the abutment surface 84 being formed at another side upward projection 86 of the guide block 60. In this sense, the guide block 60 is formed by a lower projection 68 and an upper projection 86 which are mirror-symmetrical with respect to the central axis. In this case, the projections 68, 86 may be integrally formed with or secured to the remainder of the guide block 60 in a suitable manner.

Specifically, according to fig. 2 to 11 and 13, the pivot mechanism 28 further has a pivot frame 88, and the pivot frame 88 may be a sheet metal member bent at a plurality of places and inclined upward. The pivot frame 88 is fastened in a pattern and manner not shown from below to the guide block 60 of the swing drive unit 24. A gripping section 90 is mounted on the pivot carriage 88 in the region of the front in fig. 2 to 5, by means of which gripping section 90, owing to the fixed connection of the pivot carriage 88 to the guide block 60, the pendulum drive unit 24 and the components and subassemblies carried thereby, in particular the pivot drive unit 24 and the feed device 22, can be pivoted manually about the pivot axis 30 away from the workpiece spindle 20 or close to the workpiece spindle 20. In addition to some covers and seals, the figures also show in part a rubber skirt 92 as spray protection in the region of the pivot axis 30 and two bellows covers 94 (see fig. 6, 7 and 11) with a sheet metal slide 96 and a rubber sleeve 98, which sleeve 98 is passed through with the feed device 22 while being sealed with respect to the working space 18, the pivot carriage 88 also carrying the hood 36 shown in fig. 1 for opening and closing the polishing machine 14.

Further details of the wobble drive unit 24 can be seen in fig. 6 to 9, 13 and 14. Thus, the guide block 60 has a central opening 100 at the rear with respect to the front side of the polisher 14 to receive the servomotor 102 and secure the servomotor 102 at the guide block 60. From the opening 100, a central stepped through bore 104 extends through the guide block 60, a threaded rod 106 of a ball screw is mounted to extend through the through bore 104, the spindle 106 being rotatably driven by a servomotor 102. The guide block 60 also has a respective continuous bearing hole 108 on each side of the through hole 104, the bearing holes 108 being parallel to the through hole 104 and serving to receive ball sleeve pairs (not shown in greater detail). In the guide holes 108, two guide rods 110 are mounted in the guide block 60 by means of a longitudinally displaceable ball sleeve pair. On the motor side (servomotor 102) of the guide block 60, the guide rods 110 are connected together at the ends by guide plates 112, the guide plates 112 having a central opening for the servomotor 102 to pass through (see fig. 4 and 6), while the guide rods 110 are connected together by guide heads 114 at the ends on the other side of the guide block 60. According to fig. 4 and 10, the nut 116 of the ball screw, which engages the screw 106, is fastened in the guide head 114. In this sense, it is evident that the guide head 114 together with the guide rod 110 and the guide plate 112 are axially displaced relative to the guide block 60 by means of the ball screws 106, 116 driven by the servomotor 102.

A carrier 118 for the sheet metal slide 96 of the corrugated cover 94 is attached to the guide head 114. In addition, a pivot shaft 120 is rotatably mounted on the guide head 114, the pivot yoke 122 of the pivoting drive unit 26 being fastened to this pivot shaft 120. The pivoting drive unit 26 also comprises ｃA stroke module 124 described in more detail in document EP- ｃA-2298498, to which reference is made as to the construction and function of the stroke module 124 in order to avoid repetition of the description. The stroke module 124 is pivotally connected by one end thereof to the guide plate 112 of the swing drive unit 24, and is pivotally connected by the other end thereof to the pivot yoke 122 at a distance from the pivot shaft 120. The pivoting yoke 122, which is pivotably supported on the guide head 114 of the pendulum drive unit 24, can thus be pivoted about the pivot axis 120 (pivot adjustment axis B) in a defined manner by actuation of the stroke module 124, wherein the length of the stroke module 124 changes.

The pivoting yoke 122 of the pivoting drive unit 26 also carries the feeding device 22. More precisely, and in particular according to fig. 4, 5 and 13, the substantially U-shaped pivoting yoke 122 has receiving sections 126 on both sides of its limbs, at which receiving sections 126 the feed device 22 is fixed, so that the feed device 22 can be pivoted jointly about the pivoting axis 120 (pivoting adjustment axis B) by the pivoting yoke 122. In the illustrated embodiment, the feed device 22 includes a double-acting tool cylinder 128, also often referred to as a "spindle sleeve/tip sleeve (Pinolen)", which cylinder 128 is known per se and, in this sense, need not be described in greater detail. In the case of these tool cylinders 128, a burnishing tool W like known per se is mounted to run freely and is pivotable at the free end of its piston rod. Thus, by suitable pressure loading of the tool cylinder 128, the polishing tool W can thus be lifted off or lowered onto the ophthalmic lens L and pressed against the ophthalmic lens L (linear movement Z1, Z2), in which case the polishing tool W is rotationally carried by the ophthalmic lens L. However, different forms of feed device are likewise conceivable, optionally also with ｃA rotary drive for the polishing tool as described in document EP- ｃA-2298498.

As can be readily seen in particular in fig. 10 to 12, the workpiece spindles 20 are flange-coupled from above on the base body 38 in the working space 18 and each workpiece spindle 20 extends through the working space via a drive shaft 130 and an actuating mechanism for a collet chuck 132, by means of which collet chuck 132 an ophthalmic lens L blocked on a blocking member (not shown in greater detail) can be clamped to the workpiece spindle for axial fixing and can be brought about rotationally. The main cylinder 134 of the actuating mechanism can be seen in the drawing, the cylinder 134 being used to open and close the collet chuck 132 in a manner known per se.

In addition, below the base body 38, i.e. outside the working space 18, a rotary drive 136, which in the illustrated embodiment is a variable speed asynchronous three-phase motor, is flanged via a motor flange 138. The workpiece spindles 20 projecting into the working space 18 can be driven jointly by a rotary drive 136 via a belt drive 140 to rotate about the workpiece rotation axes C1, C2 at a predetermined rotational speed. In this case, according to fig. 6, 7 and in particular to fig. 10 and 12, the belt drive 140 comprises, in addition to a pulley 142 at the workpiece spindle 20, a pulley or belt gear 144 driven by the rotary drive 136, a belt 146 which in the embodiment shown is a toothed belt, and a tensioning and return pulley 148 for the belt 146. The tension and return pulley 148 is seated between the workpiece spindle 20 and is mounted on the rotary drive 136, more precisely on the motor flange 138, offset from the pulley 144, so that the belt 146 can be tensioned by pivoting the rotary drive 136 about its axis of rotation. In this case, the rotary drive 136 is screwed to the base body 38 by means of screws (optionally nuts, both not shown), which extend through bent slots (likewise also not shown) formed in the electrode flange 138 or in the base body 38 and which allow the rotary drive 136 to pivot to tension the belt 146 before tightening the screw connection.

The above-mentioned polishing machine 14 may thus make possible, for example, a procedure which is only a description of one ophthalmic lens L, since the corresponding "RX working" second ophthalmic lens L is processed by polishing simultaneously in a similar manner. In order to fit the polishing tool W and the ophthalmic lens L to be processed on the polishing machine 14, the upper part of the polishing machine 14 is pivoted upward about the pivot shaft 30 and then pivoted downward again, so as to facilitate access to the working space 18, and after fitting together the polishing tool W and the ophthalmic lens L to be processed, the inclination angles of the feed device 22 and the polishing tool W with respect to the workpiece rotation axes C1, C2 are first set to predetermined values by means of the pivot drive unit 26 in accordance with the geometry to be processed of the ophthalmic lens L (pivot adjustment B axis). In the case of the "tangential movement" which has been explained in the introduction, the inclination angle is not changed during the actual polishing (alternatively, however, it can also be changed dynamically in the sense of a "radial movement"). Then, by means of the swing drive unit 24, the polishing tool W is moved to a position (swing axis X) where the polishing tool W opposes the eyeglass lens L. Thus, the polishing tool W is axially lowered onto the ophthalmic lens L by means of the feed device 22 until it comes into contact with the ophthalmic lens L (linear movements Z1, Z2). The feed of the polishing medium is now started and the spectacle lens L is set into a rotating state by the electronic rotary drive 136(C1, C2), in which case the spectacle lens carries the polishing tool W in contact. Then, the polishing tool W is oscillated on the spectacle lens L by a relatively small stroke (oscillation axis X) by means of the oscillation drive unit 24 so that the polishing tool W is guided over different surface areas of the spectacle lens L. In this case, too, the polishing tool slightly moves back and forth (linear movements Z1, Z2) following the geometry (noncircular shape) of the spectacle lens L being polished. Finally, after stopping the feed of the polishing medium and stopping the rotational movement of the eyeglass lens (workpiece rotational axes C1, C2), the polishing tool W is lifted off the eyeglass lens L by means of the feed device 22 (linear movements Z1, Z2). Finally, the polishing tool W is moved into the rear parking position (swing axis X) by the swing drive unit 24, at which time the upper part of the polishing machine is pivoted upward about the pivot shaft 30 (pivot movement S), and the spectacle lens L can be easily removed from the polishing machine 14. The closing or holding action performed by the positioning and closing mechanism 70, more precisely the air cylinder 72 of this mechanism, can be additionally ensured by a safety limit switch (not shown) which opens the light to ensure that the polishing process can only be started when the upper part of the polishing machine is closed, i.e. pivoted down.

Finally, fig. 15 schematically shows a particularly economical control architecture of the flexible production unit 10 according to fig. 1. According to this architecture, the polishing machine 14 is connected as a module with the generator 12 by means of an electrical connection 150 (for example, a bus system). In this respect, however, only the generator 12 has equipment for human-machine communication HMI (human-machine interface) and for control by a numerical control centre, which in the embodiment shown is in the form of a PC-based controller that controls not only the drive module of the generator 12 but also the drive module (servo amplifier/converter) of the polishing machine 14. In short, the polishing machine 14 does not have individual "intelligence" here, but only the electrical components required for generating the actual travel commands for the axes to be adjusted or controlled, namely the position-controlling swing axis X (X axis for short) of the swing drive unit 24 for the polishing tool W, the pivoting adjustment axis B (B axis for short) of the pivoting drive unit 26 for the polishing tool W, and the speed-governing axes C1, C2 (C axis for short) of the workpiece spindle 20 which holds and drives the ophthalmic lens L by means of the rotary drive 36.

A polishing machine, in particular for ophthalmic lenses, comprising: at least one workpiece spindle projecting into the working space for rotationally driving the ophthalmic lens about a workpiece axis of rotation; at least one feed device for lowering and raising the polishing tool relative to the ophthalmic lens; a swing drive unit for reciprocating the feed device in a swing direction extending substantially transversely to the workpiece rotation axis during polishing; and a pivot drive unit to pivot the feed device about a pivot adjustment axis extending in a direction substantially perpendicular to the workpiece rotation axis and substantially normal to the swing direction. In order to provide a very compact and ergonomically suitable polishing machine, a pivoting mechanism is provided by means of which the feed device, the swing drive unit and the pivoting drive unit can be moved relative to the workpiece spindle from a relatively closed position to a relatively open position and vice versa with the working space open.

List of reference numerals:

10 Flexible manufacturing unit

12 generators

14 polishing machine

16 turning tool

18 work space

20 workpiece spindle

22 feeding device

24 swing drive unit

26 pivoting drive unit

28 pivoting mechanism

30 pivot axis/axle

32 frame

34 cover member

36 protective cover

38 base body

40 flange section

42 bearing surface

44 rear wall

46 mounting member

48 mounting bottom

50 inner mounting arm

52 outer mounting arm

54 screw

56 through hole

58 threaded hole

60 guide block

62 support element

64 through hole

66 gas compression spring

68 lower projection

70 positioning and closing mechanism

72 cylinder

74 cylinder shell

76 piston rod

78 bracket

80 adjustable abutment

82 shock absorber

84 abutment surface

86 upper projection

88 pivoting rack

90 gripping section

92 rubber skirt

94 corrugated cover

96 metal plate slide

98 rubber sleeve

100 opening

102 servo motor

104 through hole

106 screw

108 bearing hole

110 guide rod

112 guide plate

114 seeker

116 nut

118 carrier

120 pivot axis

122 pivoting yoke

124 stroke module

126 receive segment

128 cutter cylinder

130 drive shaft

132 spring collet

134 air cylinder

136 rotary drive

138 motor flange

140 belt drive

142 belt pulley

144 pulley

146 strap

148 tension and return wheel

150 electric connector

B tool pivot axis (Polisher)

B_DWorkpiece rotation axis (angularly positioned control; generator)

C1 workpiece rotation axis of right cutter (adjustable rotation speed; polishing machine)

C2 workpiece rotation axis of left cutter (adjustable rotation speed; polishing machine)

cc second optically effective surface

cx first optically effective surface

F_DTool swing axis (position control; at the generator's fast tool servo system)

HMI device for human-computer interaction

L workpiece/spectacle lens

W tool/polishing tool (Polisher)

S pivoting movement (Polisher)

X tool axis of oscillation (position control; polishing machine)

X_DLinear axis of the work (position control; generator)

Linear movement of Z1 right-hand tool (uncontrolled; polisher)

Linear movement of Z2 right-hand tool (uncontrolled; polisher)

Claims (18)

1. An apparatus (14) for finishing an optically active surface (cc, cx) of a workpiece (L), comprising:

at least one workpiece spindle (20), the workpiece spindle (20) projecting into a working space (18) and by means of which workpiece spindle (20) the workpiece (L) to be machined can be driven in rotation about a workpiece rotation axis (C1, C2);

at least one feed device (22) for a tool (W), by means of which feed device (22) the tool (W) can be moved (Z1, Z2) towards or away from the workpiece (L);

a swing drive unit (24), by means of which swing drive unit (24) the feed device (22) is capable of reciprocating in a swing direction (X) extending substantially transversely to the workpiece rotation axis (C1, C2) during machining; and

a pivoting drive unit (26), by means of which pivoting drive unit (26) the feed device (22) is pivotable about a pivoting adjustment axis (B) which extends in a direction substantially perpendicular to the workpiece rotation axis (C1, C2) and substantially normal to the swing direction (X),

characterized by a pivoting mechanism (28), by means of which pivoting mechanism (28) the feed device (22), the swing drive unit (24) and the pivoting drive unit (26) can be pivoted (fig. 3) relative to the workpiece spindle (20) from a relatively closed position (fig. 2) to a relatively open position (fig. 3) to open the working space (18) with the working space (18) open, and can be pivoted (S) in the opposite direction.

2. The device (14) according to claim 1, wherein the workpiece (L) is an ophthalmic lens.

3. The device (14) as claimed in claim 1, characterized in that the pivot mechanism (28) has a common pivot axis (30) for the feed device (22), the pendulum drive unit (24) and the pivot drive unit (26), the feed device (22), the pendulum drive unit (24) and the pivot drive unit (26) being jointly pivotable about the common pivot axis (30) away from the workpiece spindle (20) or close to the workpiece spindle.

4. A device (14) as claimed in claim 3, characterized in that the pivot axis (30) is located behind the working space (18) as seen from the position of the operator.

5. The device (14) according to claim 3, wherein the pivot axis (30) extends in a direction substantially parallel to the pivot adjustment axis (B).

6. The device (25) according to claim 4, wherein the pivot axis (30) extends in a direction substantially parallel to the pivot adjustment axis (B).

7. The device (14) as claimed in any of claims 1 to 6, characterized in that the pivoting mechanism (28) has a pivoting carriage (88) with a gripping section (90), by means of which gripping section (90) the feed device (22), the swing drive unit (24) and the pivoting drive unit (26) can be pivoted manually away from the workpiece spindle (20) and can be pivoted (S) in the opposite direction.

8. The device (14) of claim 7, wherein the pivot mount (88) carries a shroud (36) for opening and closing the device (14).

9. The device (14) according to any one of claims 1 to 6, wherein the pivoting mechanism (28) comprises at least one spring element (66), the spring element (66) facilitating the pivoting of the feed device (22), the swing drive unit (24) and the pivot drive unit (26) away from the workpiece spindle (20).

10. The device (14) as claimed in any of claims 1 to 6, characterized by a positioning and closing mechanism (70), which positioning and closing mechanism (70) holds the feed device (22), the swing drive unit (24) and the pivot drive unit (26) in their closed position during machining and ensures a substantially vertical alignment of the linearly extending swing direction (X) relative to the workpiece rotation axis (C1, C2).

11. The device (14) as claimed in claim 10, characterized in that the positioning and closing mechanism (70) comprises a pressure medium cylinder (72), the pressure medium cylinder (72) serving to hold the feed device (22), the swing drive unit (24) and the pivot drive unit (26) in their closed position.

12. The device (14) according to claim 10, wherein the positioning and closing mechanism (70) comprises at least one adjustable abutment (80), the adjustable abutment (80) optionally comprising a shock absorber (82), and by means of which adjustable abutment (80) the orientation of the oscillation direction (X) with respect to the workpiece rotation axis (C1, C2) can be adjusted.

13. The device (14) according to claim 11, wherein the positioning and closing mechanism (70) comprises at least one adjustable abutment (80), the adjustable abutment (80) optionally comprising a shock absorber (82), and by means of which adjustable abutment (80) the orientation of the oscillation direction (X) with respect to the workpiece rotation axis (C1, C2) can be adjusted.

14. The device (14) as claimed in any of claims 3 to 6, characterized by a base body (38), the base body (38) delimiting the working space (18) and bearing the workpiece spindle (20), two mountings (46) supporting the workpiece axis (30) being fastened to the base body (38), wherein the pendulum drive unit (24) comprises a guide block (60) which is pivotably mounted on the pivot axis (30) between the two mountings (46).

15. The apparatus (14) of claim 14, wherein the swing drive unit (24) comprises: two guide rods (110), the two guide rods (110) being supported in a longitudinally displaceable manner in the guide block (60); a seeker (114); and a guide plate (112), wherein the guide rods (110) are connected together by means of the guide head (114) on one side of the guide block (60) and on the other side of the guide block (60) the guide rods (110) are connected together by means of the guide plate (112), and wherein the guide head (114) is displaceable relative to the guide block (60) by means of a screw drive (106, 116).

16. The device (14) according to claim 15, wherein the pivot drive unit (26) has a pivot yoke (122), the pivot yoke (122) carrying the feed device (22) and being pivotably supported on the guide head (114) of the pendulum drive unit (24), wherein a stroke module (124) is arranged between the pendulum drive unit (24) and the pivot yoke (122), by means of which stroke module (124) the pivot yoke (122) can be pivoted about the pivot adjustment axis (B).

17. The device (14) as claimed in any of claims 1 to 6, characterized by two work spindles (20), the two work spindles (20) projecting into the working space (18) and being drivable by a belt drive (140) for rotation about the work rotation axes (C1, C2), the belt drive (140) comprising a pulley (144) driven in rotation by a rotary drive (136), a belt (146) and a tension and return pulley (148) for the belt, the tension and return pulley (148) being seated between the work spindles (20) and being mounted on the rotary drive (136) in an offset manner from the pulley (144) such that the belt (146) can also be tensioned by pivoting of the rotary drive (136).

18. Flexible production unit (10) for the preliminary machining and finishing of an ophthalmic lens (L), comprising:

preliminary machining device (12) for preliminary machining an optically active surface (cc, cx) of the ophthalmic lens (L) by milling, turning and/or grinding, the preliminary machining device (12) comprising an adjustment drive axis or a controlled drive axis (B) for the workpiece and/or tool_D、F_D、X_D) And has an associated drive module, and

finishing device (14) for finishing an optically active surface (cc, cx) of the ophthalmic lens (L) by polishing, in particular according to any one of claims 1 to 17, the finishing device (14) comprising an adjustment or controlled drive axis (B, C1, C2, X) for workpieces and/or tools and having an associated drive module, and the finishing device (14) being coupled as a module to the preliminary machining device (12) for preliminary machining,

wherein only the primary machining device (12) has a human machine interface device (HMI) and a numerical control center controller that control the drive modules of both the primary machining device (12) and the finishing device (14).