DE102009061843B3 - Device for blocking optical workpieces, in particular spectacle lenses - Google Patents

Abstract

Device (10) for blocking optical workpieces (L), in particular spectacle lenses, with a first movement device (12) for rotating a workpiece (L) blocked on a block piece (S) about a workpiece axis of rotation (B), the workpiece (L ) has a first optically active surface (cx) and a second optically active surface (cc) and, prior to blocking, is blocked with the first optically active surface (cx) by means of a block material (M) on a block surface (F) of the block piece (S) is, a nozzle assembly (14) with a nozzle (D) for the delivery of a pressure medium high pressure jet (HDS) in a direction essentially transverse to the workpiece axis of rotation (B) on an edge area between the blocked workpiece (L) and the block piece ( S) and a second movement device (16) by means of which the blocked workpiece (L) and the nozzle (D) can be brought into a defined position relative to one another, characterized in that the nozzle assembly (14) emitted from the nozzle (D) flat pressure medium high pressure jet (HDS) on a predetermined point of impact (MAP) in the edge area between the first optically effective surface (cx) of the workpiece (L) and the block surface (F) of the block piece (S) can be directed to the workpiece (L) to block from the block piece (S), with an adjustment angle (α) of the nozzle (D) for blocking based on a plane perpendicular to the workpiece axis of rotation (B) between 5 ° and 25 °, and that a further nozzle is provided by means of the a further high pressure pressure jet can be emitted onto the workpiece (L) in order to peel off the block material (M) still adhering to the workpiece (L) from the workpiece (L).

Description

TECHNICAL AREA

The present invention relates generally to a device for blocking optical workpieces according to the preamble of claim 1.

In optics production, "blocking" or "blocking" for short is the general term used to describe the process in which an optical workpiece is temporarily attached to a so-called "block piece" using a suitable material (low-melting alloy - so-called "alloy" or adhesive). or the block material is applied to the workpiece in order to form the block piece itself, which then serves to hold the workpiece in the respective processing machine and / or coating system. Correspondingly, in optics production, the process is called "blocking" in which the optical workpiece is separated from the block piece / block material again after it has been processed and / or coated.

In particular, the invention relates to a device for blocking spectacle lenses. Ophthalmic lenses are blocked en masse in so-called "RX workshops" before the respective blocked ophthalmic lens on its rear or front surface with regard to its optical effect and / or on the edge for fitting into an assigned spectacle frame with a geometrically defined cutting edge (milling / turning) or geometrically undefined cutting edge (grinding / polishing) machined and / or coated on its rear or front surface to achieve additional effects (increase in scratch resistance, anti-reflective properties, mirroring, hydrophobic properties, etc.).

When “spectacle lenses” are generally referred to below in connection with the present invention as a preferred field of application, this includes optical lenses or lens blanks (blanks) for spectacles made from common materials such as polycarbonate, mineral glass, CR 39, HI index, etc. and to be understood with any (pre) shape of the peripheral edge of the lens or the lens blank, which before blocking has already been (pre) processed and / or (pre) coated on one or both optically effective surface (s) and / or on the edge can but do not have to be. The spectacle lens can also be coated with a film, a lacquer or the like on its surface on which it is / is blocked. be provided in order to protect this surface from contamination and damage and / or to improve the adhesive properties between the spectacle lens and the block material, without this being specifically mentioned in the following.

STATE OF THE ART

There is no lack of proposals in the prior art as to how a device can be designed for the automated blocking of spectacle lenses, a pressure medium such as water being used to release the spectacle lens from the block piece by applying hydraulic forces, either from the "inside" a pressure medium channel in the block piece, which opens at the block surface of the block piece facing the lens (e.g. DE 10 2005 038 063 A1 , 12th ; WO 03/018253 A1 , 4th ), or from “outside” by means of a high-pressure water jet emitted by a nozzle, which strikes an edge point between the block piece and the lens (for example EP 2 042 265 A1 , based on WO 2008/003805 A1 , 1 ).

A disadvantage of the “internal” application of the hydraulic forces can be seen in the fact that the block piece is provided with cavities which are open towards the block surface and which oppose a desirable full-surface support of the spectacle lens on the block piece. It is true that the opening in the block area can in principle be reduced in size in order to achieve almost full-area support. But then it is hardly possible to apply the hydraulic forces that are required to separate the spectacle lens from the block piece.

This can of course be remedied by using a small piston in the (separate) block piece, which also limits the block area, as in the WO 03/018253 A1 (Fig. 14 to 22nd ) suggested as an alternative. When blocking, however, mechanical forces are then applied via this piston to a relatively small, central area on the spectacle lens, which can lead to the spectacle lens being destroyed. After all, it is important to generate forces during detachment that are higher than the adhesive forces between the lens and the block piece. In the case of the piston solution described above, the detachment forces act on the center of the spectacle lens, while the adhesive forces act primarily in a ring zone on the edge of the spectacle lens. Particularly in the case of thin lenses, this can lead to relatively strong deformations and high stresses in the lens to be blocked, which can ultimately cause the lens to break - apart from the effort involved in providing such a piston in the block piece.

The previously known “outer” solution according to the preamble of claim 1 forming EP 2 042 265 A1 allows full-surface support of the spectacle lens on the block piece and also reduces the risk of the spectacle lens being damaged when it is blocked. However, this prior art is in need of improvement in other respects.

The blocking process disclosed there was specially developed for blocking spectacle lenses blocked with a thermoplastic block material. Melting of the block material is initially forced by immersing the composite of spectacle lens, block material and block piece in a bath with hot water. The block piece and block material as well as a protective film on the spectacle lens are then detached from the spectacle lens by means of a high-pressure water jet. For this purpose, the jet water is heated to a temperature between 50 ° C and 65 ° C in order to further soften the block material and ultimately to liquefy it as a result of the heating. The high-pressure water jet fans out relatively broadly and is also rotated around the longitudinal axis of the nozzle in order to get under the protective film on the rotating spectacle lens and lift it off the lens.

A disadvantage of this prior art is seen in particular in the fact that - also as a result of the intermediate preheating step in the hot water bath - the blocking of a spectacle lens takes a relatively long time, which prevents efficient use of this method in RX workshops.

Finally, the document discloses WO 2009/102908 A1 a method of blocking a non-metallic lens block piece on a machined lens. In addition to other cutting processes, such as cutting with a hot wire or a hot blade, ultrasonic or laser cutting, a water jet cutting process with or without abrasive material can be used to cut the lens block piece near the receiving surface for the lens will. The thin part of the lens block piece that remains on the lens must then be peeled off the lens / with an adhesive film.

TASK

The invention is based on the object of creating a device for blocking optical workpieces, in particular spectacle lenses, by means of which the optical workpieces can be blocked as securely, damage-free and quickly as possible.

DISCLOSURE OF THE INVENTION

This object is achieved by the features specified in claim 1. Advantageous or expedient developments of the invention are the subject matter of claims 2 to 15.

In a device for blocking optical workpieces, in particular spectacle lenses, comprising a first movement device for rotating a workpiece blocked on a block piece about a workpiece axis of rotation, the workpiece having a first optically effective surface and a second optically effective surface and, prior to blocking, with the first optically effective surface is blocked by means of a block material on a block surface of the block piece, a nozzle assembly with a nozzle for the delivery of a pressure medium high pressure jet in a direction essentially transverse to the workpiece axis of rotation on an edge area between the blocked workpiece and the block piece and a second movement device, by means of which the blocked workpiece and the nozzle can be brought into a defined position relative to one another; According to the invention, the pressure medium high-pressure jet emitted by the nozzle of the nozzle assembly can be directed to a predetermined point of impact in the edge area between the workpiece and the block piece in order to block the workpiece from the block piece, with an adjustment angle of the nozzle for blocking based on a plane perpendicular to the workpiece axis of rotation between 5 ° and 25 °, and a further nozzle is also provided, by means of which a further pressure medium high-pressure jet can be emitted onto the workpiece in order to “peel off” the block material still adhering to the workpiece.

Because the pressure medium high-pressure jet, unlike in the generic state of the art, does not strike the separation point between block piece and block material or the separation point between block material and workpiece more or less randomly, but can be directed towards the respective separation point, it is possible to remove the workpiece to block significantly faster, which makes the device according to the invention particularly suitable for use in RX workshops. A relatively high pressure of the pressure medium can be used to further promote a fast blocking process without the risk of the workpiece being damaged by the pressure medium high-pressure jet, because it can be avoided by the defined relative position of the nozzle and block piece or workpiece, that the pressure medium high pressure jet in critically brushes over the workpiece. In particular, workpieces blocked with adhesives can be blocked quickly, safely and without damage, without the need for upstream softening and / or softening processes and / or temperature-controlled pressure medium for blocking. Since the blocking device also has the further nozzle for delivering the further pressure medium high-pressure jet onto the workpiece, any block material still adhering to the workpiece can be peeled off the workpiece by means of the additional nozzle provided for this purpose, which is also a fast blocking process is conducive to obtaining a “completely” blocked workpiece.

The first movement device is preferably a motor spindle which has a collet for receiving the block piece at an angle of rotation, the collet being able to be driven to rotate around the workpiece axis of rotation in a controlled manner (B-axis) by means of the motor spindle. Thus (at least) when the pressure medium high pressure jet is switched on, the block piece can be rotated around the workpiece axis of rotation by means of the first movement device, which accelerates the blocking process compared to a - basically possible - blocking process with the block piece held in a rotationally fixed manner.

In an expedient and cost-effective embodiment of the blocking device, the second movement device can have a Y-slide, which can be displaced in a position-controlled manner (Y-axis) along the workpiece axis of rotation by means of a servomotor and a screw drive and which carries the first movement device, i.e. the motor spindle.

In the further pursuit of the concept of the invention, a third movement device can be provided for generating a position-controlled (X-axis) relative movement between the workpiece and the nozzle for blocking in a direction essentially perpendicular to the workpiece axis of rotation, with a clear distance between the nozzle for blocking and the predetermined point of impact of the pressure medium high pressure jet is adjustable. In this way, the distance between the nozzle and the point of impact can be optimized in a simple manner with regard to the best possible (i.e. fast and reliable) blocking result. The third movement device can - again in an expedient and cost-effective embodiment - have an X-slide, which can be displaced in a position-controlled manner (X-axis) essentially perpendicular to the workpiece axis of rotation by means of a servomotor and a screw drive and which carries the nozzle for blocking.

Experiments carried out by the applicant with a commercially available flat jet nozzle as a blocking nozzle, which had a nozzle opening cross section of approx. 0.45 mm and a jet angle of approx. 25 °, in which experiments with a pressure medium high pressure jet formed from untempered tap water as pressure medium under water pressure between 100 and 140 bar, preferably 120 bar, have shown in this context that the clear distance between the nozzle for blocking and the predetermined point of impact of the pressure medium high-pressure jet should be between 15 mm and 40 mm, preferably around 20 mm to achieve a safe and fast blocking process. If the clear distance here is too small, the block material will only be detached in the middle of the fanned-out high-pressure jet; If, on the other hand, the clear distance is chosen too large, this increases the blocking time considerably.

In a further advantageous embodiment of the blocking device, the blocking nozzle can be held pivotably about an angle adjustment axis on a pivot bearing of the nozzle assembly, so that the adjustment angle of the blocking nozzle can be adjusted relative to the plane perpendicular to the workpiece axis of rotation. The tests carried out have shown that the setting angle of the nozzle for blocking, based on the plane perpendicular to the axis of rotation of the workpiece, should preferably be around 15 °. Here, the high pressure jet can either be inclined in the direction of the block piece, which enables the blocking of workpieces that have a smaller diameter than the block piece, or it can be inclined away from the block piece, which when blocking on the workpiece generates a force component that moves away from the block piece and insofar favors the separation of workpiece and block piece.

It is further preferred if the blocking device has a suction device with a suction head, which serves to hold the workpiece on its second optically effective surface facing away from the block piece when blocking it from the block piece. Thus, the suction head of the suction device can hold the workpiece at least during the discharge of the pressure medium high-pressure jet through the nozzle for blocking, which further reduces the risk of damage to the workpiece during blocking.

Furthermore, in a further advantageous embodiment of the blocking device, the suction head, which is aligned with the workpiece axis of rotation, can be moved in the direction of the workpiece axis of rotation by a piston-cylinder arrangement (linear movement Y ' ), then when the pressure medium high pressure jet is switched on by means of the Piston-cylinder arrangement, a predetermined tensile force can be applied to the workpiece via the suction head, which is sucked into the second optically effective surface when blocking. This tensile force is expediently only slightly smaller than the holding force brought about by the suction head on the workpiece, which in total is also conducive to a quick blocking process.

Finally, the further nozzle can be adapted to emit a rotating high-pressure jet of pressure medium onto the workpiece, as a result of which the block material in the blocking device can advantageously be peeled off the workpiece quickly.

Figure list

• 1 eine Draufsicht auf eine Vorrichtung zum Abblocken von Brillengläsern als optischen Werkstücken nach einem ersten Ausführungsbeispiel der Erfindung, mit einer verschwenkbaren, ansonsten aber ortsfesten Düse zur Abgabe eines abblockenden Hochdruck-Wasserstrahls sowie einer winkellagegeregelten Drehachse B und einer lagegeregelten Linearachse Y für das Werkstück;
• 2 eine Seitenansicht der Vorrichtung gemäß 1 von links in 1, die in der Zeichnungsebene um 90° im Uhrzeigersinn gedreht wurde;
• 3 eine Draufsicht auf eine Vorrichtung zum Abblocken von Brillengläsern als optischen Werkstücken nach einem zweiten Ausführungsbeispiel der Erfindung, bei dem gegenüber dem ersten Ausführungsbeispiel zusätzlich noch eine lagegeregelte Linearachse X für die Düse zur Abgabe des abblockenden Hochdruck-Wasserstrahls vorgesehen ist;
• 4 eine Seitenansicht der Vorrichtung gemäß 3 von links in 3, die in der Zeichnungsebene um 90° im Uhrzeigersinn gedreht wurde; und
• 5 eine Skizze zur Veranschaulichung der wesentlichen Geometriedaten an der Düse zur Abgabe des abblockenden Hochdruck-Wasserstrahls einerseits und an dem Verbund aus Brillenglas, Blockmaterial und Blockstück andererseits sowie der geometrischen Relativbeziehung dieser Teile zueinander, auch im Vergleich zwischen einem Zustand direkt nach dem Aufblocken (Schnittansicht oben) und einem Zustand beim Abblocken (Schnittansicht in der Mitte und zugehörige Draufsicht unten).

In the following, the invention is explained in more detail on the basis of preferred exemplary embodiments with reference to the attached schematic drawings, the same or corresponding assemblies or parts being provided with the same reference numerals and, furthermore, assemblies and parts have been omitted to simplify the illustration and for the sake of clarity, which do not appear to be necessary for an understanding of the invention (such as operating unit and control, paneling parts, supply devices, including lines, hoses and pipes for electricity, compressed air and vacuum, etc.). In the drawings show:

• 1 a plan view of a device for blocking spectacle lenses as optical workpieces according to a first embodiment of the invention, with a pivotable, but otherwise stationary nozzle for emitting a blocking high-pressure water jet and an angular position-regulated axis of rotation B. and a position-controlled linear axis Y for the workpiece;
• 2 a side view of the device according to 1 from the left in 1 , which has been rotated 90 ° clockwise in the drawing plane;
• 3 a plan view of a device for blocking spectacle lenses as optical workpieces according to a second exemplary embodiment of the invention, in which, compared with the first exemplary embodiment, a position-regulated linear axis is additionally provided X is provided for the nozzle for the discharge of the blocking high-pressure water jet;
• 4th a side view of the device according to 3 from the left in 3 , which has been rotated 90 ° clockwise in the drawing plane; and
• 5 a sketch to illustrate the essential geometric data on the nozzle for the discharge of the blocking high-pressure water jet on the one hand and on the composite of spectacle lens, block material and block piece on the other hand as well as the geometric relative relationship of these parts to one another, also in comparison between a state directly after blocking (sectional view above ) and a state during blocking (sectional view in the middle and associated top view below).

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the first embodiment according to the 1 and 2 is a device for blocking spectacle lenses L. numbered 10 as optical workpieces. The blocking device 10 generally comprises a first movement device 12th for turning the on a block piece S. blocked glasses L. around a workpiece axis of rotation B. , a nozzle assembly 14th with a nozzle D. for the delivery of a high pressure water jet (pressure medium high pressure jet HDS in 5 ) in a direction essentially transverse to the workpiece axis of rotation B. on an edge area between the spectacle lens L. and block piece S. and a second movement device 16 for generating a relative movement between the spectacle lens L. and the nozzle D. along the workpiece axis of rotation B. . The lens L. is here regarding the nozzle D. - or, as an alternative to this, not shown, the other way around, the nozzle with respect to the spectacle lens - by means of the second movement device 16 position-controlled (Y-axis) along the workpiece axis of rotation B. slidable so that the high pressure water jet HDS to a predetermined point of impact MAP (see again 5 ) in the edge area between the lens L. and block piece S. can be directed to the lens L. from the block piece S. to block, as will be explained in more detail below. In addition, a further nozzle (not shown here) is provided, by means of which a further high-pressure jet of pressure medium can be emitted onto the spectacle lens in order to “peel off” the block material from the spectacle lens that may still adhere to the spectacle lens.

The blocking device 10 is overall on a base plate 18th built up. On the baseplate 18th is first of all a console 20th the second movement device 16 attached. A Y-carriage 22nd (Workpiece slide) of the second movement device 16 is at the console 20th via two parallel arranged, in the transverse direction to the workpiece axis of rotation B. spaced linear guides 24 held longitudinally displaceable. Any linear guide 24 consists in a manner known per se of a guide rail or rod on one part (console 20th or Y-slide 22nd ) and associated guide shoes on the other part. For generating the linear movement along the workpiece axis of rotation B. , d .H. in the direction Y has the second movement device 16 a servo motor 26th on, which has a screw drive 28 with the Y-carriage 22nd is effectively connected. To the side of the Y-carriage 22nd (in 2 left) is a linear position measuring system 30th with one on the Y-carriage 22nd attached linear scale 32 and one associated therewith, on the base plate 18th or the console 20th attached read head 34 arranged. The result is the Y-carriage 22nd relative to the console 20th linearly movable or adjustable, namely CNC position-controlled in both directions of the Y-axis, with the aid of the position measuring system 30th determined position data for the Y slide 22nd .

Like in particular the 2 shows the Y-carriage carries 22nd the first moving device 12th , which in the illustrated embodiment is a roller bearing motor spindle that has a collet 36 for the rotation angle-oriented mounting of the block piece S. having. Using the motor spindle 12th is the collet 36 which, as in the earlier German patent application 10 2008 051 833.6 ( DE 10 2008 051 833 A1 ) described can be formed in the angle of rotation BAX (see. 5 ) CNC-controlled around the workpiece axis of rotation B. can be driven in rotation. To determine the angular position data required for this, is on the motor spindle 12th a hollow shaft encoder 38 intended. With 40 Finally, a release cylinder is numbered here, by means of which the spring-loaded collet 36 actuated, ie can be opened to the block piece S. to tension or to release again.

In 1 above the collet 36 is the nozzle assembly 14th about a holder 42 on the base plate 18th held. On the holder 42 is a swivel bearing 44 the nozzle assembly 14th attached, which serves the nozzle D. about an angle adjustment axis A. keep pivoting so that a setting angle α the nozzle D. (see again 5 ) based on a plane perpendicular to the workpiece axis of rotation B. is adjustable. More precisely is the nozzle D. which in the side view according to 2 viewed on the workpiece axis of rotation B. aims at an L-shaped bent tube 46 attached, which in turn is the pivot bearing 44 reaches through and can be fixed in this in the set angular position, for example by means of a clamping screw or the like (not shown). To the pipe 46 is a high pressure hose 48 connected to that with a high pressure pump P. is hydraulically connected. The high pressure pump P. is powered by an electric motor E. driven to the pressure medium, here untempered tap water, from a reservoir W. to suck in and with a high water pressure of eg 120 bar to the nozzle D. to promote. A drip pan for that from the nozzle D. released water and a return line for this water leading back to the reservoir are not shown here.

While the lens L. with its first optically effective surface cx by means of the block material M. on the block piece S. is blocked, as with reference to the 5 will be explained in more detail, is the second optically effective surface cc of the blocked lens L. in the blocking device 10 a suction device 50 opposite to. The suction device 50 has a suction head 52 with a circumferential rubber lip, the one with the workpiece axis of rotation B. is aligned and serves the lens L. when blocking from the block piece S. on the second optically effective surface cc to keep. In 1 is that on the suction head 52 suctioned spectacle lens L. shown after blocking with a dashed line.

The suction head 52 is on a drilled piston rod 54 a piston-cylinder arrangement 56 attached, also on the base plate 18th is mounted and by means of which the suction head 52 in the direction of the workpiece axis of rotation B. is movable (linear movement Y ' ), i.e. in 1 optionally to the left or to the right. This is done on the piston rod 54 an in 1 piston shown in dashed lines 58 attached, which can be acted upon pneumatically on two sides, ie from the left and right, via corresponding compressed air connections 60 the piston-cylinder arrangement 56 . At in 1 right, from the suction head 52 remote end of the piston rod 54 is a vacuum connection 62 provided over which the suction head 52 can be evacuated. It can be seen that by means of the piston-cylinder arrangement 56 above that when blocking on the second optically effective surface cc suction head 52 a predetermined tensile force on the lens L. can be applied.

Before using the 5 especially the geometric relationship between nozzle D. and block piece S. in the blocking device 10 and the function of the blocking device 10 to be described in more detail for the first and the second exemplary embodiment together, it should first be explained in which the in the 3 and 4th shown blocking device 10 according to the second embodiment of the above with reference to the 1 and 2 described blocking device 10 differs according to the first embodiment.

The main difference here is that in the 3 and 4th illustrated second embodiment, the blocking device 10 a third movement device 64 for generating a position-regulated (X-axis) relative movement between the spectacle lens L. and the nozzle D. in a direction essentially perpendicular to the workpiece axis of rotation B. possesses, which serves to provide a clear distance a _d (see again 5 ) between the nozzle D. , more precisely their exit and the predetermined point of impact MAP of the high pressure water jet HDS to be set in a defined manner.

Also the third movement device 64 assigns a console 66 on that at the base plate 18th is attached. An X slide 68 (Nozzle carriage) of the third moving device 64 is at the console 66 via two parallel arranged, in height direction in 4th spaced linear guides 70 held longitudinally displaceable. Any linear guide 70 consists in a manner known per se of a guide rail or rod on one part (console 66 or X-slide 68 ) and associated guide shoes on the other part. For generating the linear movement essentially perpendicular to the workpiece axis of rotation B. , d .H. in the direction X has the third movement device 64 one on the console 66 flanged servo motor 72 on, which has a screw drive 74 with the X slide 68 is effectively connected. Below the X carriage 68 (please refer 4th ) is a linear position measuring system 76 with one on the X slide 68 attached linear scale 78 and one assigned to it on the console 66 attached read head 80 arranged. The result is the X carriage 68 relative to the console 66 linearly movable or adjustable, namely CNC position-controlled in both directions of the X-axis, with the help of the position measuring system 76 determined position data for the X slide 68 . How finally 3 and 4th show the X-carriage carries 68 the holder 42 for the nozzle assembly 14th .

In the upper part of the 5 is now a not yet on its second optically effective surface cc and not yet at its edge R. Machined blank made of, for example, plastic for a spectacle lens L. shown with its first optically effective surface cx by means of the block material M. on the block area F. of the block piece S. is blocked. With the block material M. it is, for example, a UV-curing adhesive mixture as described in WO 2009/003660 A1 is described. The block piece shown here S. also consists of a plastic and is the subject of WO 2009/106296 A1 as well as the older German patent application 10 2008 051 833.6 ( DE 10 2008 051 833 A1 ), refer to the structure and function of the block piece at this point S. referenced. Regarding a suitable (on) blocking method and a suitable (on) blocking device, refer to the earlier international application PCT / EP2009 / 003324 ( WO 2009/135689 A1 ) to refer.

The block piece S. is in the upper part of the 5 shown in a sectional view, the cutting plane through an angular reference axis AX of the block piece S. runs that - according to the German standard DIN 58766 - through suitable recesses on the block piece S. is defined and serves the block piece S. in an assigned receptacle or collet (not shown here) around the workpiece axis of rotation B. to orientate angularly. The reference number REF referred to in 5 a (height) reference point on the block piece S. on which the workpiece axis of rotation B. a plane intersects which an annular bearing surface AF of the block piece S. contains, with which the block piece S. on the assigned receptacle or collet (not shown here) rests around the block piece S. in the direction of the workpiece axis of rotation B. , so to be positioned in terms of height. The block piece S. has related to the reference point REF a (minimum) height e on in 5 lowest point of the block area F. . In the embodiment shown, the latter is a sphere with a predetermined radius r .

In the lower part of the 5 is the blocked lens L. after (minor) processing on its second optically effective surface cc and machining on its peripheral surface R. shown, both in section and in an associated plan view. This was the lens L. compared to the illustration in the upper part of the 5 by an angle of approx. 65 ° counterclockwise around the workpiece axis of rotation B. rotated so that the angular reference axis AX has a different angular position.

As in particular the top view of 5 It can be seen that in the example shown, the spectacle lens has L. as a result of the machining of the edge surface R. starting from an originally circular circumferential contour of the blank (dashed in plan view), an elliptical circumferential contour drawn in bold here is obtained. The ellipse thus formed has a minor axis n and a big axis d on, the latter of which with the angular reference axis AX of the block piece S. a (fixed) angle GAX around the workpiece axis of rotation B. includes. As the sectional view shows, the edge surface was machined R. of the lens L. also the block piece S. Machined in the edge area.

The lower part of the 5 is also the relative position of the nozzle D. regarding the blocked lens L. when blocking the lens L. from the block piece S. refer to. Here q and denote first β the nozzle opening cross-section ( q ) at the nozzle outlet D. or the angle ( β ) the fan-out of the jet from the nozzle D. released pressure medium high pressure jet HDS . The one with regard to the fanning out of the pressure medium high pressure jet HDS essentially mean point of impact (or point of impact) of the pressure medium high-pressure jet HDS on the composite of spectacle lens L. , Block material M. and block piece S. is with MAP marked. The middle point of impact MAP of the pressure medium high pressure jet HDS is in the radial direction from the workpiece axis of rotation B. with the (variable) ellipse radius r _e spaced, the size of which obviously depends on the angle of rotation of the lens L. or the block piece S. around the workpiece axis of rotation B. changes. With BAX is the (variable) angle denoted by the radius of the ellipse r _e at the middle point of impact MAP of the pressure medium high pressure jet HDS with the angular reference axis AX of the block piece S. includes. In other words, it is the radius of the ellipse r _e depending on the respective rotational position of the block piece S. around the workpiece axis of rotation B. , d .H. from the respective angle BAX [i.e. r _e = f (BAX)].

The relative position of the nozzle D. and blocked lenses L. in the blocking device 10 is now defined by the angle of incidence or setting angle α the nozzle D. , d .H. of the pressure medium high pressure jet emitted by it HDS based on a plane perpendicular to the workpiece axis of rotation B. , the (radial) distance x _d the outlet opening of the nozzle D. to the reference point REF on the block piece S. in the X direction and the (height) distance y _d the outlet opening of the nozzle D. to the reference point REF on the block piece S. in the Y direction.

The setting angle α the nozzle D. should be firmly preset between 5 ° and 25 °, with a smaller angle for flat curves (= larger radius r the block area F. ) and a larger angle for steep curves (= smaller radius r the block area F. ) is better. The setting angle is preferably α the nozzle D. approx. 15 °, which has turned out to be a good compromise for a normal curve range in the tests carried out by the applicant.

The radial distance x _d the outlet opening of the nozzle D. to the workpiece axis of rotation B. can be permanently preset, as in the first exemplary embodiment according to FIGS 1 and 2 , in which no X-axis is provided. Are then for example eyeglass lenses L. with a (maximum) diameter ( d ) between 50 mm and 90 mm, the nozzle will D. at a fixed distance x _d of preferably approx. 65 mm to the workpiece axis of rotation B. set, which produced good results in the experiments carried out by the applicant. Basically, the radial distance applies x _d to the workpiece axis of rotation B. should be adjusted so that the clear distance a _d (please refer 5 ) between the outlet opening of the nozzle D. and the middle point of impact MAP of the pressure medium high pressure jet HDS on the composite of spectacle lens L. , Block material M. and block piece S. is between 15 mm and 40 mm; preferably the clearance should be a _d here be approx. 20 mm.

mit dem Ellipsenradius r_e aus $$r_e=\sqrt{{\left(a\cdot \text{cos}\left(\text{arctan}\frac{a\cdot \text{sin}w}{b\cdot \text{cos}w}\right)\right)}^2+{\left(b\cdot \text{sin}\left(\text{arctan}\frac{a\cdot \text{sin}w}{b\cdot \text{cos}w}\right)\right)}^2},$$

wobei $$a=\frac{d}{2},b=\frac{n}{2}\text{ und }w=BAX-GAX\cdot$$

Ist hingegen auch eine Verstellmöglichkeit in Richtung X vorgesehen, wie bei dem zweiten Ausführungsbeispiel gemäß den 3 und 4 mit X-Achse, so bestimmen sich die Düsenabstände x_d und y_d bezüglich des Referenzpunkts REF am Blockstück S mit dem Ellipsenradius r_e aus der obigen Formel und dem gewünschten lichten Abstand a_d von Düse D und Auftreffpunkt MAP (z.B. a_d = 20 mm) nach den folgenden Beziehungen: $$x_d=r_e+\mathrm{\Delta }{x}_d,$$

wobei $$\mathrm{\Delta }{x}_d=a_d\cdot \text{cos}\alpha ,$$

und $$y_d=r-\sqrt{r^2-r_e^2}+e+\text{tan}\alpha \cdot \mathrm{\Delta }{x}_d.$$

Grundsätzlich ist es möglich, die relative Düsenposition (y_d und ggf. x_d ) vor dem eigentlichen Abblockvorgang (1.) für eine gegebene Winkelposition (BAX) des Brillenglases L bzw. des Blockstücks S bezüglich der Werkstück-Drehachse B nach den obigen Beziehungen zu berechnen, (2.) CNC-technisch durch Verstellen in der Y-Achse und ggf. der X-Achse anzufahren und während des eigentlichen Abblockvorgangs (3.) beizubehalten, wobei dann das Blockstück S mit dem Brillenglas L um die Werkstück-Drehachse B gedreht wird. Bevorzugt ist es allerdings, die relative Düsenposition (y_d und ggf. x_d ) während des eigentlichen Abblockvorgangs (3.') in Abhängigkeit von der jeweiligen Winkelposition (BAX) des Brillenglases L bzw. des Blockstücks S bezüglich der Werkstück-Drehachse B mit zu verändern, und zwar durch CNC-technisches Verfahren in der Y-Achse und ggf. der X-Achse während der Drehung des Brillenglases L, so dass infolge koordinierter Bewegung in den B-, Y- und ggf. X-Achsen der Druckmittel-Hochdruckstrahl HDS höhenmäßig stets im Grenzbereich zwischen Blockstück S und Blockmaterial M auftrifft [d.h.: y_d = f(BAX)], nach Zurücklegung des ggf. stets gleichen Wegs a_d von der Austrittsöffnung der Düse D zum Auftreffpunkt MAP [ggf.: x_d = f(BAX)].Should the pressure medium high pressure jet HDS in terms of height in the border area between block pieces S. and block material M. at the edge of the compound of spectacle lens L. , Block material M. and block piece S. hit, which is preferred, the relative Y-position of the nozzle can be determined D. (Distance y _d ) with respect to the reference point REF on the block piece S. with a fixed relative X-position of the nozzle D. (constant distance x _d ) according to the following relationships: $$y_d=r-\sqrt{r^2-r_e^2}+e+\text{tan}\alpha \cdot \left(x_d-r_e\right),$$

with the radius of the ellipse r _e the end $$r_e=\sqrt{{\left(a\cdot \text{cos}\left(\text{arctan}\frac{a\cdot \text{sin}w}{b\cdot \text{cos}w}\right)\right)}^2+{\left(b\cdot \text{sin}\left(\text{arctan}\frac{a\cdot \text{sin}w}{b\cdot \text{cos}w}\right)\right)}^2},$$

whereby $$a=\frac{d}{2},b=\frac{n}{2}\text{and}w=\mathrm{B.}\mathrm{A.}X-G\mathrm{A.}X\cdot$$

However, it is also an adjustment option in the direction X provided, as in the second embodiment according to the 3 and 4th with the X-axis, the nozzle spacing is determined x _d and y _d regarding the Reference point REF on the block piece S. with the radius of the ellipse r _e from the above formula and the desired clearance a _d from nozzle D. and point of impact MAP (e.g. a _d = 20 mm) according to the following relationships: $$x_d=r_e+\mathrm{\Delta }{x}_d,$$

whereby $$\mathrm{\Delta }{x}_d=a_d\cdot \text{cos}\alpha ,$$

and $$y_d=r-\sqrt{r^2-r_e^2}+e+\text{tan}\alpha \cdot \mathrm{\Delta }{x}_d.$$

In principle, it is possible to change the relative nozzle position ( y _d and possibly x _d ) before the actual blocking process (1.) for a given angular position ( BAX ) of the lens L. or the block piece S. with respect to the workpiece axis of rotation B. to be calculated according to the above relationships, (2.) CNC-technically to approach by adjusting the Y-axis and possibly the X-axis and to keep it during the actual blocking process (3.), then the block piece S. with the lens L. around the workpiece axis of rotation B. is rotated. However, it is preferred to set the relative nozzle position ( y _d and possibly x _d ) during the actual blocking process (3. ') depending on the respective angular position ( BAX ) of the lens L. or the block piece S. with respect to the workpiece axis of rotation B. with to change, namely by CNC-technical process in the Y-axis and possibly the X-axis during the rotation of the spectacle lens L. , so that as a result of coordinated movement in the B, Y and possibly X axes, the pressure medium high pressure jet HDS in terms of height always in the border area between block pieces S. and block material M. hits [ie: y _d = f (BAX)], after covering the possibly always the same path a _d from the outlet of the nozzle D. to the point of impact MAP [possibly: x _d = f (BAX)].

In the tests carried out by the applicant when using a commercially available flat jet nozzle from Kärcher, which has a nozzle opening cross-section, good results were achieved, in particular with regard to the blocking speed q of approx. 0.45 mm and a beam angle β of approx. 25 °, when using tap water at a lower temperature as the pressure medium, with a water pressure between 100 and 140 bar, preferably 120 bar. Here, the flat jet nozzle was mounted around its longitudinal axis with regard to its rotational angle orientation in such a way that, as in 5 Below you can see the fanning out of the pressure medium high pressure jet HDS in a viewing direction parallel to the workpiece axis of rotation B. (Top view in 5 ) completely ("triangle" with 25 ° side angle), in a viewing direction perpendicular to the workpiece axis of rotation B. (middle sectional view in 5 ) but could not be recognized at all (line).

1. (i) Einlegen eines auf einem Blockstück S geblockten Brillenglases L in die Abblockvorrichtung 10, so dass das Blockstück S von der ersten Bewegungseinrichtung (Motorspindel 12) um die Werkstück-Drehachse B drehbar gehalten wird,
2. (ii) Berechnen einer Relativlage der Düse D bezüglich des Blockstücks S, bei der die Düse D auf die vorbestimmte Auftreffstelle MAP im Randbereich zwischen Brillenglas L und Blockstück S zielt,
3. (iii) CNC-technisches Einstellen (Y-Achse) der berechneten Relativlage von Düse D und Blockstück S mittels der zweiten Bewegungseinrichtung 16,
4. (iv) Einschalten des Druckmittel-Hochdruckstrahls HDS, der von der Düse D in Richtung der vorbestimmten Auftreffstelle MAP im Randbereich zwischen Brillenglas L und Blockstück S abgegeben wird, um das Brillenglas L vom Blockstück S zu trennen,
5. (v) Ausschalten des Druckmittel-Hochdruckstrahls HDS nachdem sich das Brillenglas L vom Blockstück S getrennt hat und
6. (vi) Entnehmen des abgeblockten Brillenglases L aus der Abblockvorrichtung 10.

The main steps of one with the blocking device described above 10 (first or second exemplary embodiment) possible blocking process for spectacle lenses L. can now be summarized as follows:

1. (i) Load one on a block piece S. blocked glasses L. into the blocking device 10 so that the block piece S. from the first movement device (motor spindle 12th ) around the workpiece axis of rotation B. is held rotatable,
2. (ii) Calculating a relative position of the nozzle D. regarding the block piece S. at which the nozzle D. on the predetermined point of impact MAP in the edge area between the lens L. and block piece S. aims,
3. (iii) CNC-technical setting (Y-axis) of the calculated relative position of the nozzle D. and block piece S. by means of the second movement device 16 ,
4. (iv) Switching on the pressure medium high pressure jet HDS coming from the nozzle D. in the direction of the predetermined point of impact MAP in the edge area between the lens L. and block piece S. is released to the lens L. from the block piece S. to separate,
5. (v) Switching off the pressure medium high pressure jet HDS after the lens L. from the block piece S. has separated and
6. (vi) Remove the blocked lens L. from the blocking device 10 .

Bearing in mind the above explanations for 5 Here, steps (ii) and (iii) in both exemplary embodiments include the calculation or CNC-technical setting (Y-axis) of the height position y _d the nozzle D. with respect to the reference point REF on the block piece S. to go with the nozzle D. on the predetermined point of impact MAP in the edge area between the lens L. and block piece S. to aim.

In the second embodiment according to the 3 and 4th the steps (ii) and (iii) can furthermore be a calculation or a by means of the third movement device 64 Caused CNC-technical setting (X-axis) of the radial position x _d the nozzle D. with respect to the reference point REF on the block piece S. embrace to the nozzle D. from the predetermined point of impact MAP in the edge area between the lens L. and block piece S. also to be spaced in a defined way (clear distance a _d ).

If in addition the block piece S. at least in step (iv) by means of the first movement device (motor spindle 12th ) also around the workpiece axis of rotation B. is rotated, it is preferred if, in addition, the height position in step (iv) y _d the nozzle D. with respect to the reference point REF on the block piece S. depending on the respective angular position BAX of the block piece S. calculated as described above and by means of the second movement device 16 (Y-axis) is adjusted or tracked [ie: y _d = f (BAX)], so that the pressure medium high pressure jet HDS always in the border area between block pieces S. and block material M. hits. This in turn applies to both exemplary embodiments.

In the second embodiment according to the 3 and 4th there is also the possibility of the radial position in step (iv) x _d the nozzle D. with respect to the reference point REF on the block piece S. depending on the respective angular position BAX of the block piece S. to be calculated and by means of the third movement device 64 (X-axis) to set or to track [i.e.: x _d = f (BAX)] so that the pressure medium high pressure jet HDS after leaving the nozzle D. always after covering an essentially constant distance (clear distance a _d of preferably 20 mm) at the point of impact MAP in the edge area between the lens L. and block piece S. hits.

Designed with further sub-steps, the entire blocking process can be represented in a semi-automatic sequence as follows: First, the blocking device 10 a "job ticket" or one on the block S. Scanned in provided code (“data matrix”; not shown) in order to query the machining parameters or the block piece status, including in particular the radius r the block area F. of the respective block piece S. and its height e related to the reference point REF , as well as the geometry information of the machined, blocked spectacle lens L. used for calculating the radius of the ellipse r _e are required when the block piece S. was machined at the edge so that the edge of the block piece S. deviates from the original circular shape with a known diameter, namely the elliptical axes d and n as well as the angle GAX . Then the blocked lens L. into the blocking device 10 inserted, ie by means of the block piece S. on the collet 36 the motor spindle 12th tense.

After pressing the start button (not shown) an automatic sequence of steps then begins, in which the door (not shown) of the blocking device is first opened 10 is closed. Then the axles move Y and possibly X into the (start) position (s) calculated as described above, whereupon the piston-cylinder arrangement 56 moves forward, ie the suction head 52 the suction device 50 in 1 respectively. 3 in the direction Y ' shifts to the left so that the rubber lip of the suction head 52 on the second optically effective surface cc of the lens L. arrives at the plant.

As a result, the vacuum connection 62 a negative pressure on the suction head 52 created so that it is attached to the lens L. sucks. Then the piston-cylinder arrangement 56 so pneumatically pressurized that their piston 58 strives to the suction head 52 over the piston rod 54 in 1 respectively. 3 in the direction Y ' to the right of the lens L. move away. However, this does not succeed because of the piston-cylinder arrangement 56 via the suction head 52 on the lens L. applied tensile force is set so that it is slightly smaller than that by the suction head 52 on the lens L. created holding force.

Then the high pressure jet HDS turned on while the lens L. about the block piece S. by means of the motor spindle 12th is preferred to rotate. To follow this rotation is the suction head 52 regarding the piston rod 54 equipped with a corresponding freewheel (not shown). As already described, the relative position between the block piece can now S. and nozzle D. by means of the second movement device 16 and, if necessary, the third movement device 64 depending on the angle of rotation in Y or X can be adjusted or tracked, with the aim of the high pressure jet HDS always between block material M. and block piece S. to be aligned (Y-axis) and the free beam length (clear distance a _d ) of the high pressure jet HDS to be kept constant if necessary (X-axis).

If as a result of the superimposed action of high pressure jets HDS and tensile force on the lens L. the lens L. with the block material M. now from the block piece S. separates, so can the piston rod 54 and with it the piston 58 the piston-cylinder arrangement 56 in 1 respectively. 3 move to the right again. In the 1 respectively. 3 The right end position of these parts is detected by a sensor (not shown) which emits a signal which indicates that the spectacle lens L. from the block piece S. is blocked.

Then the high pressure jet HDS switched off and the axes (Y and possibly X) move back to their starting position. About that on the lens L. adhesive block material M. from the first optically effective surface cx of the lens L. not having to pull it off by hand, another rotating high-pressure jet is used in the blocking device, which is emitted by the additional nozzle (not shown) provided specifically for this purpose in order to peel the block material from the spectacle lens. The blocking device door 10 opens and spectacle lens L. and block piece S. can be removed separately.

Finally, a decision has to be made as to whether the block piece S. can be reused after appropriate cleaning or must be disposed of if, for example, the edge has been machined.

List of reference symbols

10

Blocking device

12th

first movement device

14th

Nozzle assembly

16

second movement device

18th

Base plate

20th

console

22nd

Y slide

24

Linear guide

26th

Servo motor

28

Screw drive

30th

Position measuring system

32

Linear scale

34

Read head

36

Collet

38

Hollow shaft encoder

40

Relaxation cylinder

42

holder

44

Swivel bearing

46

pipe

48

High pressure hose

50

Suction device

52

Suction head

54

Piston rod

56

Piston-cylinder arrangement

58

Pistons

60

Compressed air connection

62

Vacuum connection

64

third movement device

66

console

68

X slide

70

Linear guide

72

Servo motor

74

Screw drive

76

Position measuring system

78

Linear scale

80

Read head

α

Adjustment angle of the nozzle in relation to a plane perpendicular to the workpiece axis of rotation

β

Jet fanning of the nozzle

ad

Clear distance from the nozzle to the point of impact of the high pressure jet

A.

Angle adjustment axis of the nozzle

AF

Support surface on the block piece

AX

Angular reference axis on the block piece

B.

Workpiece axis of rotation (angular position controlled)

BAX

Angle between the middle point of impact of the high pressure jet and the angular reference axis on the block piece

cc

second optically effective surface on the lens

cx

first optically effective surface on the lens

d

major axis of the ellipse

D.

jet

e

Height of the block piece in relation to the reference point on the block piece

E.

Electric motor

F.

Block area on the block piece

GAX

Angle between the major axis of the ellipse and the angular reference axis on the block piece

HDS

Pressure medium high pressure jet / high pressure water jet

L.

Workpiece / lens

M.

Block material

MAP

Middle point of impact or point of the pressure medium high pressure jet

n

minor axis of the ellipse

P.

high pressure pump

q

Nozzle opening cross-section

r

Radius of the block area on the block piece

re

Ellipse radius at the middle point of impact of the high pressure jet

R.

Edge surface on the lens

REF

Reference point on the block piece

S.

Block piece

W.

Reservoir for pressure medium

xd

Nozzle distance to the reference point on the block piece in the X direction

X

Linear axis nozzle slide (position-controlled)

yd

Nozzle distance to the reference point on the block piece in the Y direction

Y

Linear axis workpiece slide (position-controlled)

Y '

Linear movement suction cup (uncontrolled)

Claims (15)

Device (10) for blocking optical workpieces (L), in particular spectacle lenses, with a first movement device (12) for rotating a workpiece (L) blocked on a block piece (S) about a workpiece axis of rotation (B), the workpiece ( L) has a first optically active surface (cx) and a second optically active surface (cc) and, before blocking, with the first optically active surface (cx) by means of a block material (M) on a block surface (F) of the block piece (S) is blocked, a nozzle assembly (14) with a nozzle (D) for the delivery of a pressure medium high pressure jet (HDS) in a direction essentially transverse to the workpiece axis of rotation (B) on an edge area between the blocked workpiece (L) and the block piece (S) and a second movement device (16) by means of which the blocked workpiece (L) and the nozzle (D) can be brought into a defined position relative to one another, characterized in that the nozzle assembly (14) from the nozzle (D) released pressure medium high pressure jet (HDS) on a predetermined point of impact (MAP) in the edge area between the first optically effective surface (cx) of the workpiece (L) and the block surface (F) of the block piece (S) can be directed to the workpiece (L) to block from the block piece (S), an adjustment angle (α) of the nozzle (D) for blocking based on a plane perpendicular to the workpiece axis of rotation (B) being between 5 ° and 25 °, and that a further nozzle is provided by means of the a further high pressure pressure jet can be emitted onto the workpiece (L) in order to peel off the block material (M) still adhering to the workpiece (L) from the workpiece (L). Device (10) according to Claim 1 , characterized in that the first movement device is a motor spindle (12) which has a collet (36) for receiving the block piece (S) at an angle of rotation, the collet (36) at the angle of rotation ( BAX) can be driven in a controlled manner around the workpiece axis of rotation (B). Device (10) according to Claim 1 or 2 , characterized in that the second movement device (16) has a Y-slide (22) which can be moved in a position-controlled manner (Y-axis) along the workpiece axis of rotation (B) by means of a servomotor (26) and a screw drive (28) and the first moving device (12) carries. Device (10) according to one of the preceding claims, characterized by a third movement device (64) for generating a position-controlled (X-axis) relative movement between the workpiece (L) and the nozzle (D) for blocking in a direction essentially perpendicular to the workpiece -Axis of rotation (B), whereby by means of the third movement device (64) a clear distance (a _d ) between the nozzle (D) for blocking and the predetermined point of impact (MAP) of the pressure medium high pressure jet (HDS) can be set. Device (10) according to Claim 4 , characterized in that the third movement device (64) has an X slide (68) which can be displaced in a position-controlled manner (X axis) essentially perpendicular to the workpiece axis of rotation (B) by means of a servomotor (72) and a screw drive (74) and the nozzle (D) helps to block. Device (10) according to one of the preceding claims, characterized in that the nozzle (D) for blocking is held on a pivot bearing (44) of the nozzle assembly (14) so that it can pivot about an angle adjustment axis (A), so that the adjustment angle (α) of the The nozzle (D) for blocking is adjustable in relation to the plane perpendicular to the workpiece axis of rotation (B). Device (10) according to one of the preceding claims, characterized in that a suction device (50) with a suction head (52) is provided, which serves to pull the workpiece (L) on the second optically effective surface when blocking from the block piece (S) (cc) to hold. Device (10) according to Claim 7 , characterized in that the suction head (52) aligned with the workpiece axis of rotation (B) can be moved by a piston-cylinder arrangement (56) in the direction of the workpiece axis of rotation (B) (linear movement Y '), whereby by means of the piston Cylinder arrangement (56) over the at Blocking on the second optically active surface (cc) sucked in suction head (52), a predetermined tensile force can be applied to the workpiece (L). Device (10) according to Claim 8 , characterized in that by means of the piston-cylinder arrangement (56) via the suction head (52) of the suction device (50) on the workpiece (L), a tensile force can be applied which is only slightly smaller than that through the suction head (52) on the Holding force caused by workpiece (L). Device (10) according to one of the preceding claims, characterized in that the pressure medium high pressure jet (HDS) emitted by the nozzle (D) for blocking during the blocking is formed from untempered tap water as pressure medium and a water pressure between 100 and 140 bar, preferably 120 bar. Device (10) according to one of the preceding claims, characterized in that the nozzle (D) for blocking is a flat jet nozzle with a nozzle opening cross section (q) of approx. 0.45 mm and a jet angle (β) of approx 25 °. Device (10) according to one of the preceding claims, characterized in that the setting angle (α) of the nozzle (D) for blocking is approximately 15 ° in relation to the plane perpendicular to the workpiece axis of rotation (B). Device (10) according to one of the preceding claims, characterized in that the setting angle (α) of the nozzle (D) for blocking is set in relation to the plane perpendicular to the workpiece axis of rotation (B) so that the nozzle (D) The high pressure pressure jet (HDS) emitted for blocking is inclined away from the block piece (S) in order to generate a force component when blocking on the workpiece (L) which points away from the block piece (S) and thus separates the workpiece (L) and the block piece (S) favored. Device (10) according to one of the Claims 1 until 12th , characterized in that the setting angle (α) of the nozzle (D) for blocking based on the plane perpendicular to the workpiece axis of rotation (B) is set so that the nozzle (D) for blocking. block emitted pressure medium high pressure jet (HDS) is inclined in the direction of the block piece (S) in order to enable the blocking of workpieces (L) that have a smaller diameter than the block piece (S). Device (10) according to one of the preceding claims, characterized in that the further nozzle is adapted to emit a rotating pressure medium high pressure jet onto the workpiece (L).

Images