LOADING WORKPIECES IN A COATING SYSTEM

Abstract

The invention relates to a loading device for workpieces (16) in a coating system (10) and a method for loading the workpieces (16). An upright stand (22) has a number of openings (24) arranged above one another in an outward-facing surface (44). A number of insertion sleeves (30) are provided for accommodation in the openings (24), with the insertion sleeves (30) each having a shaft (32) and a retaining structure (24) as well as a borehole (26) to accommodate a workpiece (16). The openings (24) and the shafts (32) of the insertion sleeves (30) are designed such that the insertion sleeves (30) are insertable through the openings (24). The openings (24) and the retaining structures (34) are designed such that holding engagement occurs between the insertion sleeves (30) and the openings (24).

Claims

1. A loading device for workpieces in a coating system with: at least one stand arranged upright with an outward-facing surface in which a number of openings are arranged above one another; and a number of insertion sleeves for accommodation in the openings, with the insertion sleeves each having a shaft and a retaining structure as well as a borehole to accommodate a workpiece; wherein the openings and the shafts of the insertion sleeves are designed such that the insertion sleeves are insertable in the openings; and wherein the openings (24) and retaining structures are designed such that a holding engagement results between the insertion sleeves and the openings.

2. A loading device according to claim 1, wherein the retaining structures include a stop designed so that it cannot be inserted through the openings.

3. A loading device according to claim 1, wherein the retaining structures have recesses on the circumference of the insertion sleeves (30) for engaging with the edges of the openings.

4. A loading device according to claim 1, wherein the openings have a first, wider portion and a second, narrower portion, wherein the retaining structures engage with the edge of the second portion.

5. A loading device according to claim 1, wherein the openings and the retaining structures are designed so that the insertion sleeves are able to be guided through the openings in an insertion position perpendicular to the outer surface of the stand and the insertion sleeves in the inserted state can be tilted by a working angle with respect to the insertion position.

6. A loading device according to claim 1, wherein the insertion sleeves are fixated in the openings with respect to the stand.

7. A loading device according to claim 1, wherein the insertion sleeves are accommodated in the holder in such a way that the boreholes are arranged at an upward slant.

8. A loading device according to claim 1, wherein a plurality of openings have the same shape and dimension.

9. A loading device according to claim 1, wherein there are openings on the stand arranged in a staggered and/or skewed manner with respect to one another.

10. A loading device according to claim 1, wherein an arrangement of openings (24) above one another on the stand is formed such that with the existing engagement with the insertion sleeves accommodated therein these are arranged with at least two different angles with respect to the stand.

11. A loading device according to claim 1, wherein the stand is made as a sheet metal part and the insertion sleeves are made as turned parts.

12. A loading device according to claim 1, wherein a device is provided for rotating the stand about a vertically situated axis of rotation (A).

13. A coating system with: a coating chamber; a loading device according to one of the preceding claims inside the coating chamber; and coating agents for applying a coating to the workpieces held in the loading device.

14. A coating system according to claim 13, wherein the coating chamber is designed as a vacuum chamber, and the coating agents are designed to produce a plasma.

15. A method for loading workpieces in a coating system, wherein workpieces are inserted in boreholes of insertion sleeves, with the insertion sleeves each having a shaft and a retaining structure, and the insertion sleeves are inserted in openings arranged above one another in an outward-facing surface of at least one stand which is arranged upright by inserting the shafts (32) through the openings, wherein a holding engagement is formed between the retaining structures of the insertion sleeves and the openings.

Description

[0038] An embodiment of the invention is described below in more detail based on drawings. These show in:

[0039] FIG. 1 a perspective, partially schematic view of a coating system with a loading device;

[0040] FIGS. 2a, 2b perspective views of parts of the loading device from FIG. 1;

[0041] FIG. 3 various insertion sleeves for the loading device from FIG. 1 in a perspective view;

[0042] FIG. 4 part of the loading device in a top view;

[0043] FIG. 5 a representation of the part from FIG. 4 in cross section;

[0044] FIGS. 6a-6d a representation of the part of the loading device from FIG. 4, FIG. 5 in a side view for various positions.

[0045] FIG. 1 shows a coating system 10 in a partially schematic view. For example, it can be a PVD coating system with a vacuum chamber 12 in which multiple magnetron cathodes 14 are situated (of which only one is shown as an example in FIG. 1) with which a plasma can be produced in the interior of the vacuum chamber 12, the constituents of which are deposited to form a surface coating on workpieces 16.

[0046] The workpieces 16 are arranged inside the chamber 12 on a loading device 20. This is positioned on a rotating plate 18 which can turn around a vertical axis of rotation A, and comprises a number of standing vertical holders 22 which are situated next to one another. Whereas for the sake of clarity only three holders 22 are shown situated next to one another in FIG. 1, the loading device 20 comprises a greater number of such holders 22, for example 18, which are arranged next to one another altogether in the shape of the circle on the rotating plate 18. Here the loading device 20 provides external loading in which the workpieces 16 are arranged in a stationary manner on the holder 22 facing outward in each case.

[0047] As seen in FIG. 4, for example, each of the holders 22 is a sheet metal bent part made of sheet metal bent at an angle. A number of openings 24 are cut out above one another in a flat, upright, outward-facing surface 44 of each holder 22.

[0048] As shown in FIG. 2a, 2b for example, insertion sleeves 30 are inserted in the openings 24 when the holder 22 is equipped. The insertion sleeves 30 have a borehole 26 in the center in each case. The workpieces 16 are inserted into the boreholes 26. Here the boreholes 26 each have a limited drill depth so the workpieces 16 can only be inserted up to the drill depth and thus assume a defined position.

[0049] The workpieces 16 in the example shown are pin-shaped, cylindrical parts such as drill bits, router bits, etc. However, workpieces of other shapes which have a cylindrical shaft can also be inserted in the boreholes 26.

[0050] As shown in FIG. 3, various types of insertion sleeves 30 are used to accommodate workpieces 16 with different shaft diameters, said sleeves having identical external dimensions but boreholes 26 of differing diameter. For example, with an insertion sleeve 30 external diameter of 14 mm, boreholes 26 with diameters of 6 to 12 mm can be provided to accommodate therein workpieces shafts which are in each case fitting or respectively of slightly smaller diameter. Here the workpieces 16 are simply inserted loosely in the boreholes 26 without further attachment or locking being urgently necessary.

[0051] In alternative embodiments, insertion sleeves 30 can be provided with boreholes of different diameters. The different diameters of the boreholes in this case are understandably to be chosen based on the respective external diameters of the insertion sleeves 30 used. An alternative design of the holder 22 can, for example, be one providing a greater number of openings 24 with a smaller diameter. For example, insertion sleeves 30 with an external diameter of 10 mm can be inserted in these openings 24, with the various insertion sleeves 30 having borehole diameters from 2 to 8 mm for example.

[0052] In general, the borehole diameters can thus be chosen based on the external diameter of the insertion sleeves and, for example, be in the range from 20 to 85% of the external diameter.

[0053] Due to their identical external dimensions, the various insertion sleeves 30 with differing borehole diameter function as adapters to arrange different workpieces 16 with differing shaft diameters on the same holder 22 of the loading device 20. Depending on the shaft length of the workpieces 16, the drill depth can also be adapted.

[0054] Each of the insertion sleeves 30 has an externally circular cylindrical shaft 32 and a head 34 with a circumferential groove 36 and a flange 38. The insertion sleeves 30 are rotationally symmetric so they can be fabricated as turned parts in a single piece. By using metal such as steel, particularly stainless steel, electric contacting of the inserted workpieces 16 can take place via the holder 22, which is also metallic.

[0055] The shape of the openings 24 is shown in FIG. 4 and FIG. 5. These comprise in each case a first, wider portion 28a and a second, narrower portion 28b. In the example shown, the portions 28a and 28b are each approximately semicircular, with the wider portion 28a with a larger diameter situated above and the narrower portion 28b with a smaller diameter below.

[0056] The spacing of the openings 24 in the two portions 28a and 28b does not run exactly perpendicular here, but instead is in each case in a slightly turned arrangement by about 15 degrees with respect to the horizontal. Here the openings 24 are situated in a counter rotated arrangement among themselves in each case, so they have an angle of rotation of about 30 degrees with respect to one another. As shown below, this serves to produce a staggered arrangement at different angles of the insertion sleeves 30 with respect to one another on the holder 22.

[0057] The insertion sleeves 30 are inserted in the holder 22 as described below with respect to FIGS. 6a to 6d. Here, the shaft 32 of a sleeve 30 is first inserted through the respective opening 24 horizontally and thus at a right angle to the upper right outer surface 44 of the holder 22 (FIG. 6b). The opening 24 and in particular its wider upper portion 28a are dimensioned so that the shaft 32 can be easily inserted through it with a little play.

[0058] The head 34 of the insertion sleeves 30 forms a retaining structure for fixating the insertion sleeve 30 on the holder 22. Here the flange 38 is dimensioned so that it cannot be inserted all the way through the opening 24 due to its larger external diameter and thus functions as a stop during insertion (FIG. 6c). In this position, the circumferential groove 36 can be brought into engagement with the edge of the opening 24, particularly the edge of the lower portion 28b.

[0059] Here the diameter of the insertion sleeve 30 is smaller than the diameter of the opening 24 in the area of the groove 36, so that it is accommodated therein with play. Consequently, the insertion sleeve 30 is not fixated in its orientation, i.e. the working angle relative to the holder 22, but instead can be tilted. As shown in FIG. 6d, after insertion the insertion sleeve 30 is tilted with respect to the horizontal by an angle of about 10 degrees, for example, so the borehole 26 is skewed slightly upward. At this working angle, the inserted workpiece 16 cannot fall out of the insertion sleeve 30.

[0060] As seen in particular in FIG. 2b, the insertion sleeves 30 assume positions which are staggered with respect to one another due to the openings 24 (FIG. 4) situated in a staggered arrangement among themselves in the direction of rotation as described above. The insertion sleeves 30 protrude from the holder 22 toward the inside and the workpieces 16 accommodated therein protrude outward from the outer surface 44 of the holder 22 with the aforementioned small working angle with respect to the horizontal. Here they do not extend in an exactly radial manner in each case, but rather point in staggered directions with respect to one another. Thus the workpieces 16 in the equipped loading device (FIG. 2a) are not parallel to one another on a holder 22, but instead have a staggered arrangement.

[0061] The insertion sleeves 30 used are locked on the holder 22 by a locking strip 40 (FIG. 2b). The locking strip 40 has a comb-like structure with a number of parallel teeth 42. The locking strip 40 is attached on the holder 22 in such a way that in each case the teeth 42 lie on the shaft 32 of the insertion sleeves 30 and lock these in the tilted position (see FIG. 6d for example). Thus the insertion sleeves 30 and the workpieces 16 inserted therein are stationary and immovably fixated with respect to the holder 22.

[0062] The coating system 10 from FIG. 1 can thus be used for coating various workpieces 16 by first of all putting together insertion sleeves 30 which fit the respective workpieces 16. The insertion sleeves 30 are then inserted in the openings 24 on the holders 22 as described and locked using the locking strip 40. With this, the loading device 20 is prepared and the workpieces 16 can be inserted. Alternatively, the insertion sleeves 30 can also be used with workpieces 16 already inserted in the openings 24.

[0063] After loading has taken place in this way, the chamber 12 can be closed and the coating process can be started. During it the rotating plate turns so the workpieces loaded outward are passed by the cathode 14 in each case such that the desired coating is deposited. After the coating has taken place, the workpieces 16 can be removed simply by pulling them out of the insertion sleeves 30.

[0064] For subsequent coating processes with the same batch size of workpieces 16 or their diameters, the loading device 20 can be used without modification. In the case of other loading, i.e. of workpieces 16 with a different diameter, individual insertion sleeves 30 or all of them can be replaced in accordance with the dimensions required.