Patent Application
20250033823
The invention relates to an unpacking device as claimed in claim 1, to a machining device having the same as claimed in claim 11, and to a method for removing a thin-walled packaging wrapper from a workpiece according to claim 12.
In the processing of workpieces such as optical lenses and lens blanks (hereunder all processing states of a lens blank to the finished optical lens are simply referred to as optical lens), the latter prior to processing are typically packed individually in packages. The optical lenses, in particular spectacle lens blanks, to be processed herein readily have different diameters, thicknesses and surface curvatures even before they are supplied to a first processing machine. Said optical lenses can be composed of plastics material or glass, for example. Most packages of these workpieces have a cuboid outer wrapper of cardboard from which said workpieces are to be retrieved. Moreover, the workpiece can additionally be disposed in a packaging tray of plastics material (also referred to as a blister or blister tray) or of paper. In this instance, the optical lens lies in a recess or trough of the packaging tray and is held in position so as to be protected in the interior of the cuboid outer wrapper.
Furthermore, the workpiece can be disposed in a thin-walled packaging wrapper, for example a film pouch, a plastic pouch, a paper pouch, a wrapping paper, a film, a wrapping film, a foamed film, a felt material, a non-woven fabric, or the like. The workpiece, or the optical lens, can in particular be inserted in a pocket of the thin-walled packaging wrapper, or be wrapped in a planer thin-walled packaging wrapper. Optionally, the thin-walled packaging wrapper can also be designed so as to be closed by welding.
Prior to commencing processing, the workpieces can be retrieved from the package manually or by machine and be deposited in so-called job trays; in the production of spectacle lenses these are in most cases optical lenses in pairs for the later spectacles. The packaging materials are separated from one another.
The high labor costs and the high level of monotony of the activity are disadvantageous in manual unpacking. After all, several ten thousand lenses are processed per day in comparatively large processing lines, for example in spectacle lens grinding shops.
A method and a device by way of which optical lenses can be retrieved from the outer packaging of cardboard are set forth in EP 3 819 092 A1. This also functions well in combination with the optional additional packaging tray. According to this prior art of technology for unpacking the optical lens from a pack, automated cutting open of a first package side of the cardboard package takes place, as well as automated sliding out of the workpiece from the cardboard package on this first package side. If a packaging tray is present, the optical lens herein can be lifted out.
For removing thin-walled packaging wrappers of the workpiece, EP 3 819 092 A1 puts forward the proposal that pouches and wrapping films are fixed by counteracting suction cups, said pouches and wrapping films then being torn open by enlarging the spacing of the suction cups. An alternative proposal lies in first securing the workpiece from the front side and the rear side, for example by clamping, and then carrying out a circumferential cut on the circumference. As soon as the circumferential cut has been carried out, the upper half of the wrapper is to be lifted in order to subsequently fix the workpiece from above and finally extract the latter from the lower half of the wrapper. However, the suction cup does not always operate reliably in the case of creased and air-permeable materials, and also due to potential contamination by the packaging material, so that this is prone to malfunctioning. The proposed circumferential cut with subsequent handling is moreover slower than the removal of the workpiece from the cuboid outer packaging, which is why this operative step is the bottleneck in unpacking with a view to the efficiency of the unpacking machine.
It is therefore an object of the invention to eliminate sources of error when unpacking the thin-walled packaging wrapper, and to design the operative step to be more cost-efficient. The solution herein is to be permanent and to function reliably.
Main features of the invention are set forth in claims 1, 11 and 12. Design embodiments are the subject matter of claims 2 to 10, and 13 to 16, and of the description hereunder.
The invention relates to an unpacking device which is designed to remove a thin-walled packaging wrapper from a workpiece, having a processing station having a workpiece receptacle for receiving the workpiece, and having a pair of counter-rotating rollers which are mounted so as to be rotatable about counter-rotating axles and between which is formed an intake gap, at least one (i.e. exactly one, at least one or both) of the counter-rotating rollers being driven by a drive so as to rotate about its counter-rotating axle. The optional drive of both counter-rotating rollers can optionally be individual drive motors per counter-rotating roller, or a common drive motor. Furthermore, the pair of counter-rotating rollers are disposed on a circumference of the processing station in such a manner and designed to draw the thin-walled packaging wrapper into the intake gap, in particular to also strip said thin-walled packaging wrapper from the workpiece.
It is advantageous here that the packaging wrapper is gripped on a surface of the workpiece by the intake gap owing to friction of the counter-rotating rollers, and can then be pulled through the intake gap. The packaging wrapper is fundamentally stripped from the workpiece. For this purpose, the workpiece should be of a dimensionally stable design, which is mostly the case with optical lenses, for example. The induction takes place rapidly and efficiently and can moreover be used in a multiplicity of packaging wrappers of various designs, so that no tooling times arise when changing between workpieces with different wrappers. In this way, the unpacking device should be designed for removing a thin-walled packaging wrapper from the group of film pouch, plastic bag, paper pouch, wrapping paper, film, wrapping film, foamed film, felt material, non-woven fabric, or the like.
It is particularly advantageous for the unpacking device to be designed for workpieces that are optical lenses (also optical lens blanks). These have two mutually opposite workpiece sides, or lens sides, of which at least one is in most instances of a curved design. Moreover, the workpiece preferably has a round workpiece circumference, or lens circumference, preferably having a workpiece or lens diameter between 40 mm and 100 mm, and furthermore preferably between 50 mm and 85 mm. The facilitates the orientation and optional rotation on the processing station. The workpiece, or the optical lens, can be composed of glass or transparent plastics material, for example.
The circumference of the processing station can in particular be at least substantially circular, whereby the rollers and/or the counter-rotating rollers are disposed in such a manner that they form a tangent to this circular circumference.
It is furthermore expedient for the pair of counter-rotating rollers to be disposed between two of the rollers, in particular ideally on one side of the processing station. In this instance, these rollers can define the spacing of the workpiece from the counter-rotating rollers. The contact pressure is preferably absorbed by way of the rollers, and the counter-rotating rollers are destressed. At least one of the remaining rollers should be disposed on the other opposite side of the processing station.
In a deviating embodiment, one of the two counter-rotating rollers is formed by one of the rollers. In this way, all rollers can be driven in the same rotational direction while the additional counter-rotating roller rotates in the opposite direction. However, it is preferable for the counter-rotating rollers to be formed separately from the rollers. This enables independent rotating speeds to be used, which improve the separation of functions between workpiece rotation and packaging induction.
The workpiece, or the optical lens, herein can in particular be inserted in a pocket of the thin-walled packaging wrapper, or be wrapped in a planar, thin-walled packaging wrapper. Optionally, the thin-walled packaging wrapper can also be designed to be closed by welding, for example.
According to an optional, more detailed, design embodiment, the workpiece receptacle has at least three (i.e. exactly three, at least three, exactly four, or at least four) rollers which are disposed so as to be rotatable about roller axles and distributed about the circumference of the processing station, and which are disposed in such a manner that a workpiece (in particular clamped) between the rollers is rotatable on the processing station by rotating the rollers, in particular in such a manner that the workpiece circumference of the workpiece is moved past the intake gap, this preferably taking place transversely past the intake gap. In the process, at least one (i.e. exactly one, at least one, exactly two, at least two, exactly three, at least three, exactly four or more than four) of the rollers is driven by a roller drive so as to rotate about its/their roller axle. It is advantageous here that the orientation of the workpiece relative to the intake gap can be varied in such a way that the probability of the packaging wrapper being initially gripped is increased, or accelerated. Moreover, the rotation of the workpiece can reduce the tensile forces acting on the packaging wrapper during induction into the intake gap. In other words, the stripping of the packaging wrapper can be implemented by way of a lesser force by rotating the workpiece.
The rollers can be designed to be cylindrical. Optionally, the rollers can have an encircling track or groove, in particular in such a manner that the workpiece can be received therein by way of its workpiece circumference. In this way, the workpiece cannot travel along the roller axle during rotation.
Rollers are understood to mean such shapes that have a length which exceeds their diameter, as well as those of which the length is smaller than their diameter.
At least two (i.e. exactly two, at least two, exactly three, at least three, exactly four, at least four, or all) of the rollers are preferably driven by a roller drive so as to rotate about their roller axle. In the optional case of at least two roller axles being driven, this can optionally be individual drive motors per roller or a common roller drive motor.
According to a special embodiment, the roller axles deviate by at most 15 degrees from a mutually parallel alignment; said roller axles are preferably aligned so as to be at least substantially mutually parallel, and said roller axles are particularly preferably aligned so as to be exactly mutually parallel. This prevents the workpiece traveling along the roller axle and enables a high radial clamping force. A minor deviation from the parallel alignment can be used, for example, to secure the workpiece on the workstation, in particular in that said workpiece can be pressed against a bearing surface by exploiting its tendency to travel toward the opening angle. However, manufacturing tolerances and stress-related deformations are permissible when considering exact parallelism. This is presently understood to mean substantially a deviation of up to 5 degrees from parallelism.
It is furthermore preferable for the roller axles to be in each case aligned vertically in geodetic terms. In this way, flat workpieces can be introduced so as to lie horizontally between the rollers in geodetic terms.
In a more detailed design embodiment of the unpacking device it is provided that at least one (i.e. exactly one, at least one, exactly two, at least two, exactly three, at least three, exactly four, at least four, or all) of the rollers are displaceably mounted in such a manner that the size of the processing station between the rollers is variable as a result. In this way, a workpiece can be comfortably introduced between the rollers and then be fixed on the workpiece circumference by said rollers, for example. Moreover, workpieces having different diameters can be received.
The displaceably mounted roller, or the displaceably mounted rollers, is/are optionally driven by a displacement drive.
At least the roller, or the rollers, driven by the roller drive so as to rotate about its/their roller axle preferably has/have a rubberized contact surface. A high torque can be applied to the workpiece in this way without the latter having to be excessively clamped.
It can furthermore optionally be provided that the counter-rotating axles deviate by at most 15 degrees from a mutually parallel alignment, preferably are aligned so as to be at least substantially mutually parallel, and particularly preferably aligned so as to be exactly mutually parallel. An at least substantially homogenous induction speed across the length of the intake gap is achieved in this way. However, manufacturing tolerances and stress-related deformations are permissible when considering exact parallelism. This is presently understood to mean substantially a deviation of up to 5 degrees from parallelism. The counter-rotating axles are preferably aligned vertically in geodetic terms.
It is optionally provided in particular that the roller axles and the counter-rotating axles deviate by at most 15 degrees from a mutually parallel alignment, preferably are aligned so as to be at least substantially mutually parallel, and particularly preferably aligned so as to be exactly mutually parallel. In this way, the mentioned axles and the corresponding rollers are able to be disposed next to one another in a space-saving manner, and this results in a simple construction. However, manufacturing tolerances and stress-related deformations are permissible when considering exact parallelism. This is presently understood to mean substantially a deviation of up to 5 degrees from parallelism.
The intake gap over its length can have only substantially, at least substantially, or exactly the same width. In this way, it tends to be irrelevant at which point along the counter-rotating axles the packaging wrapper makes its way into the intake gap. Moreover, the width of the intake gap can be reduced to zero by way of simple kinematics, and the counter-rotating rollers can bear on one another by way of a contact pressure force.
In a preferred embodiment, the intake gap has a width which is actively adjustable by an adjustment drive, and/or the counter-rotating rollers are loaded toward one another by a spring force of a spring. In this way, the width can be actively adjusted, or else pre-adjusted, and/or adapts resiliently to the width during operation, for example when thick spots or material accumulations of the packaging wrapper are inducted.
At least one (i.e. exactly one, at least one, or both) of the counter-rotating rollers preferably has a rubberized contact surface. Alternatively, at least one (i.e. exactly one, at least one, or both) of the counter-rotating rollers can be designed as a roller brush. Both assist in increasing the frictional force in relation to the packaging wrapper and in improving the induction behavior with the counter-rotating rollers.
It can furthermore be provided that the processing station has a bearing surface on which the workpiece is to be placed adjacent to the counter-rotating rollers. This simplifies the handling of the workpiece because the latter can temporarily bear thereon without having to be held by the rollers, for example for loading and unloading.
Additionally, the unpacking device can optionally have a loading device which is designed to transport a workpiece to the processing station and/or remove said workpiece from the processing station, in particular to push a workpiece laterally onto the bearing surface of the processing station and/or to push a workpiece laterally from the bearing surface of the processing station. Loading and unloading can be performed in an automated manner in this way.
There is furthermore the option that the unpacking device has a detector which is designed to detect whether the thin-walled packaging wrapper is removed from the workpiece. For this purpose, the detector can optionally be designed to detect the presence of the thin-walled packaging wrapper on the workpiece, for example by an optical detector. Alternatively, this can optionally be achieved by a detector which is designed to detect, for example optically or mechanically, the thin-walled packaging wrapper on the side of the intake gap that faces away from the processing station. Furthermore alternatively, the detector can optionally be designed to detect the induction of the thin-walled packaging wrapper based on forces and/or movements that act on one or both of the counter-rotating rollers, in particular tensile and/or compressive forces and/or torques and/or changes in the width of the intake gap.
The unpacking device according to the invention herein can be disposed as a module in the superordinate unpacking device according to EP 3 819 092 A1. This superordinate unpacking device for unpacking a workpiece, in particular an optical lens or an optical lens blank, from a package has a supply station which is designed to receive a package in which a workpiece is disposed. Moreover, said superordinate unpacking device has a cutting station having a first cutting or sawing tool which is designed to cut open a first package side of the package in an automated manner behind the supply station. Finally, said superordinate unpacking device also has a discharge station behind the cutting station, which is designed to generate a relative movement between the package and the workpiece in an automated manner, by way of which the workpiece is discharged from the package on the first package side. In terms of the optional design embodiments of the superordinate unpacking device according to EP 3 819 092 A1, reference is made to the full content of EP 3 819 092 A1.
The preferred location for the disposal of the unpacking device in the superordinate unpacking device according to EP 3 819 092 A1 is behind the discharge station of the latter. Moreover, said unpacking device is preferably disposed in front of the workpiece holder of said superordinate unpacking device in order to receive the workpiece in a mechanized manner. In this way, after being discharged all retrieved workpieces can still be relieved of any thin-walled packaging wrapper potentially present if required by the present unpacking device.
The invention moreover relates to a processing device having an unpacking device as described above and hereunder, and a processing machine, the unpacking device being disposed along an automated conveyor line in front of the processing machine, and unpacked workpieces being transported by the conveyor line from the unpacking device to the processing machine, the processing machine being from the following group: milling machine, turning machine, grinding machine, polishing machine, coating machine, cleaning machine, film-wrapping machine, and block-mounting machine. In this way, a workpiece that has been relieved of the thin-walled packaging wrapper in an automated manner can be provided to the processing machine.
The invention furthermore relates to a method for removing a thin-walled packaging wrapper from a workpiece, comprising the steps:
Thin-walled packaging wrappers are removed from a workpiece reliably and rapidly in this simple way. For this purpose, the pair of counter-rotating rollers should be driven so as to rotate in opposite directions about their counter-rotating axles.
An optional method step lies in rotating the workpiece, by way of a workpiece circumference, transversely past the intake gap, either prior to gripping the thin-walled packaging wrapper by way of the intake gap, in particular for increasing the probability that the thin-walled packaging wrapper makes its way into the intake gap; and/or when inducting the thin-walled packaging wrapper into the intake gap, in particular for facilitating the stripping of the thin-walled packaging wrapper from the workpiece. The rotation of the workpiece can thus promote the start of the induction as well as the progress of the induction of the packaging wrapper.
Changing the direction of rotation of the workpiece is optionally possible in the process, either prior to gripping the thin-walled packaging wrapper by way of the intake gap, in particular for increasing the probability that the thin-walled packaging wrapper makes its way into the intake gap; and/or when inducting the thin-walled packaging wrapper into the intake gap, in particular for facilitating the stripping of the thin-walled packaging wrapper. This can also serve to accelerate the initial induction or to improve the progress of stripping the packaging wrapper.
According to the method it can be provided that the workpiece for rotation is disposed on a processing station having a circumference (of the processing station), at least three (i.e. exactly three, at least three, exactly four or at least four) rollers which are disposed so as to be rotatable about roller axles and distributed about the circumference being disposed in such a manner that the workpiece is clamped between the rollers on the processing station and by rotation of the rollers is rotated on the processing station, to which end at least one (i.e. exactly one, at least one, exactly two, at least two, exactly three, at least three, exactly four, at least four, or all) of the rollers is/are driven so as to rotate about its/their roller axle by a roller drive. The rotation is easy to implement in an automated manner with the aid of the rollers.
The method should in particular be designed for workpieces which are optical lenses (also optical lens blanks). How these may be designed has been described further above. Reference is therefore made to the above.
Moreover, the method should be designed for thin-walled packaging wrappers. How these may be designed has been described further above. Reference is therefore made to the above.
The method can in particular be carried out with an unpacking device as set forth above and hereunder. Conversely, there is the option that the unpacking device is designed for carrying out the method set forth above and hereunder. The advantages apply in an analogous manner to either.
Further features, details and advantages of the invention are derived from the wording of the claims and from the following description of exemplary embodiments by means of the drawings, in which:
The unpacking device 30 has a processing station P having a workpiece receptacle 31 for receiving the workpiece 1 (only illustrated in
The roller axles RA1, RA2, RA3, RA4 are in particular disposed and driven in such a manner that the workpiece 1 (only illustrated in
Furthermore, the unpacking device 30 has a pair of cylindrical counter-rotating rollers 40, 41 which are mounted so as to be rotatable about counter-rotating axles GA1, GA2, which are aligned so as to be mutually parallel, and between which an intake gap 42 is formed. In particular the counter-rotating axles GA1, GA2 are also aligned so as to be parallel to the roller axles RA1, RA2, RA3, RA4, thus likewise aligned vertically in geodetic terms. The intake gap 42 over its length has the same width B which is actively adjustable by an adjustment drive 44. Additionally, the counter-rotating rollers 40, 41 are loaded toward one another by a spring force of a spring, and have a rubberized contact surface 47. Alternatively, the counter-rotating rollers 40, 41 could also each be designed as a roller brush.
Both of the counter-rotating rollers 40, 41 are driven by a common drive 43 (reference sign 43 only alluded to in
When the workpiece 1 (only illustrated in
Workpieces 1 of this type can be in a thin-walled packaging wrapper 10 formed from the group comprising film pouch, plastic bag, paper pouch, wrapping paper, film, wrapping film, foamed film, felt material, non-woven fabric, or the like. Shown in
A method for removing the thin-walled packaging wrapper 10 from a workpiece 1, in which offering up the workpiece 1 having the thin-walled packaging wrapper 10 to the intake gap 42 between the pair of counter-rotating rollers 40, 41, and inducting the thin-walled packaging wrapper 10 so far into the intake gap 42 that the thin-walled packaging wrapper 10 is stripped from the workpiece 1 takes place, can now be carried out with the unpacking device according to
The invention is not limited to any of the above-described embodiments but is able to be modified in many ways.
For instance, common drives can be provided, some of the rollers 32, 33, 34, 35 and counter-rotating rollers 40, 41 may not be driven, different numbers of rollers 32, 33, 34, 35 can be provided, and axial alignments of the rollers 32, 33, 34, 35 can deviate from parallelism, for example. Moreover, the rollers 32, 33, 34, 35 and counter-rotating rollers 40, 41 can be of a conical or contoured design.
The unpacking device 30 can optionally also have a loading device which is designed to transport the workpiece 1 to the processing station P and to remove said workpiece 1 from the processing station P again, for example to push said workpiece 1 laterally onto the bearing surface F of the processing station P and to push said workpiece 1 laterally from the bearing surface F of the processing station P.
All of the features and advantages, including details of the construction, spatial arrangements and method steps, derived from the claims, the description and the drawing can be relevant to the invention individually as well as in the most varied combinations.
| Number | Date | Country | Kind |
|---|---|---|---|
| 23 188 338.0 | Jul 2023 | EP | regional |
