METHOD FOR OPTICALLY INSCRIBING AND/OR MARKING ROUND STOCK

Abstract

A method for producing round stock (10) which is provided with at least one inscription and/or marking (16), at least the surface (12) of the round stock (10) consisting of a metallic material, in particular of chromium or steel, for example of hardened steel, chromium-plated steel or stainless steel. In order to improve this method such that disadvantages and shortcomings are avoided, the method includes the following steps: placing on the surface (12) at least one cover (20) which is adapted to the shape of the surface (12) and in particular has the inscription and/or marking (16), such that the region to be provided with the inscription and/or marking (16) is not covered by the cover (20),—exposing the round stock (10) to a first electrolyte (30) together with the cover (20), material being removed from the surface (12) by said electrolyte in the region to be provided with the inscription and/or the marking (16) while producing depressions (14), and—exposing the round stock (10) together with the cover (20) and the depressions (14) not covered by the cover (20) to a second electrolyte (32) by which the depressions (14) are filled to produce the inscription and/or marking (16) which differs from the surface (12) optically, in particular with respect to color. The present invention also relates to round stock (10) which is manufactured from a metallic material, with the round stock being provided with a correspondingly produced inscription and/or marking (16).

Claims

1. A method for applying an inscription or for applying a marking (16) in the form of a code on a piston rod (10) of a fluid cylinder, wherein at least a surface (12) of the piston rod (10) is embodied from a metal material, the method comprising: placing at least one covering (20) that is adapted to suit a form of the surface (12) and represents the at least one of the inscription or marking (16) on the surface (12) in such a manner that an area that is to be provided with the at least one of the inscription or marking (16) is not covered by the covering (20), exposing the piston rod (10) having the covering (20) to a first electrolyte (30) by which material is removed from the surface (12) by forming depressions (14) in the area that is to be provided with at least one of the inscription [[and/]]or marking (16), and exposing the piston rod (10) having the covering (20) and having the depressions (14) that are not covered by the covering (20) to a second electrolyte (32) by which the depressions (14) are filled so as to form the at least one of the inscription or marking (16) that is optically different to the surface (12).

2. The method as claimed in claim 1, further comprising filling the depressions (14) with black chrome, black nickel, black rhodium, black ruthenium, copper-tin alloy, copper-tin-zinc alloy or with gold.

3. The method as claimed in claim 1, wherein the covering (20) is formed by at least one mask that is embodied from a hard material having an additional seal between the mask and the surface (12) or by at least one template that is at least one of self-adhesive or under tension, or by a shrinkable material.

4. The method as claimed in claim 1, wherein the covering (20) comprises a lacquer, ink, or at least one hot-melt or hot-melt coating.

5. The method as claimed in claim 4, wherein the covering (20) is printed onto the surface (12).

6. The method as claimed in claim 1, wherein the depressions (14) are etched by the first electrolyte (30) into regions of the surface (12) that are not covered by the covering (20) and are to be provided with the at least one of the inscription or marking (16).

7. The method as claimed in claim 1, further comprising placing or immersing the piston rod (10) having the covering (20) in at least one bath or at least one solution of at least one of the first electrolyte (30) or the second electrolyte (32).

8. The method as claimed in claim 1, wherein the piston rod (10) having the covering (20) is coated using tampon-galvanic process at least in the area of the surface (12) that is not covered by the covering (20) by an electrode that is supplied with at least one of the first electrolyte (30) or the second electrolyte (32), said electrode being immersed in the at least one of the first electrolyte (30) or the second electrolyte (32).

9. The method as claimed in claim 8, wherein the electrode that is functioning as an anode is embodied from a material that is non-soluble with respect to the electrolyte as at least one plate that is encased by at least one sponge, stocking, cloth, non-woven material or wadding tampon, or as at least one rod that is encased by at least one sponge, stocking, cloth, non-woven material or wadding tampon.

10. The method as claimed in claim 1, wherein the marking (16) comprises at least one barcode.

11. The method as claimed in claim 1, wherein the fluid cylinder is a hydraulic cylinder or a pneumatic cylinder.

12. The method as claimed in claim 10, wherein the code, in particular for the purpose of optical position determination or path measurement, comprises an absolute code structure that represents the actual stroke or the actual position of the piston rod.

13.-14. (canceled)

15. The method as claimed in claim 1, wherein the method is used to inscribe or mark a chrome or stainless steel surface on at least one piston rod for at least one fluid cylinder.

16. A fluid cylinder having a piston rod that for at least one of optical position determination or path measurement has a code (16) applied to the surface and said code comprises a code structure that represents an actual stroke or actual position of the piston rod, the code (16) is applied by galvanic deposition according to the following method: placing a covering (20) that is adapted to suit a form of the surface (12) and represents the code (16) on the surface (12) in such a manner that an area that is to be provided with the code (16) is not covered by the covering (20), exposing the piston rod (10) having the covering (20) to a first electrolyte (30) by which material is removed from the surface (12) by forming depressions (14) in the area that is to be provided with the code (16), and exposing the piston rod (10) having the covering (20) and having the depressions (14) that are not covered by the covering (20) to a second electrolyte (32), by which the depressions (14) are filled so as to form the code (16) that is optically different to the surface (12).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] As already mentioned above, there are different options of configuring and further developing the doctrine of the present invention in an advantageous manner. For this purpose, on the one hand, reference is made to claims that are subordinate to claim 1, on the other hand further configurations, features and advantages of the present invention are explained in detail hereinunder, inter alia with reference to the two exemplary embodiments illustrated in FIG. 1 and FIG. 2.

[0037] In the drawings:

[0038] FIG. 1 illustrates in a schematic sequence (, namely [a.sub.1].fwdarw.[b.sub.1].fwdarw.[c.sub.1].fwdarw.[d.sub.1].fwdarw.[e.sub.1]) a first exemplary embodiment for a method in accordance with the present invention, wherein a method product in accordance with the present invention can be produced at the end of said method; and

[0039] FIG. 2 illustrates in a schematic sequence (, namely [a.sub.2].fwdarw.[b.sub.2].fwdarw.[c.sub.2].fwdarw.[d.sub.2].fwdarw.[e.sub.2]) a second exemplary embodiment for a method in accordance with the present invention, wherein a method product in accordance with the present invention can be produced at the end of said method.

[0040] Like or similar embodiments, elements or features are provided with identical reference numerals in FIG. 1 and in FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] In order to avoid superfluous repetitions, the explanations hereinunder with respect to the embodiments, features and advantages of the present invention—unless otherwise mentioned—relate to the two exemplary embodiments of the present invention illustrated with reference to FIG. 1 and FIG. 2.

[0042] It is fundamentally possible by the method illustrated in an exemplary manner with reference to FIG. 1 or with reference to FIG. 2 to produce a round stock 10 that is provided with an inscription and/or marking 16 (cf. the method step [e.sub.1] in FIG. 1 or the method step [e.sub.2] in FIG. 2). The round stock 10 is in this case by way of example a piston rod of a fluid cylinder, in particular of a hydraulic cylinder and/or a pneumatic cylinder.

[0043] The starting point of the present invention is thus the round stock 10 that is embodied from a metal material, in particular from chrome or steel, for example from hardened steel, from chromed steel or stainless steel.

[0044] A covering 20 that is adapted to suit the form of the surface 12 of this round stock 10 and reveals the inscription and/or marking 16 is placed on the surface 12 in such a manner that the area of the surface 12 that is to be provided with the inscription and/or marking 16 is not covered by the covering 20 and the remaining area is covered by the covering 20 (cf. the method step [a.sub.1] in FIG. 1 or method step [a.sub.2] in FIG. 2).

[0045] There are different exemplary options for the design of the covering 20: [0046] a mask that is embodied from a hard material, in particular from a synthetic material or from metal, having an additional seal between the mask and the surface 12; [0047] a template, in particular from a foil that is self-adhesive and/or under tension; [0048] a shrinkable material, in particular a shrinkable tube; [0049] a lacquer (printed on the surface 12) in particular a protective lacquer, spray lacquer or dipping lacquer; [0050] an ink (that is printed on the surface 12); [0051] a hot-melt or hot-melt coating.

[0052] The round stock 10 having the covering 20 is exposed to a first electrolyte 30 (cf. the method step [b.sub.1] in FIG. 1 or the method step [b.sub.2] in FIG. 2).

[0053] Material is removed from the surface 12 by this first electrolyte 30 by forming depressions 14 in the area that is to be provided with the inscription and/or marking 16 (cf. the method step [c.sub.1] in FIG. 1 or the method step [c.sub.2] in FIG. 2); in particular the depressions 14 are etched by the first electrolyte 30 into the areas of the surface 12 that are not covered by the covering 20 and are to be provided with the inscription and/or marking 16.

[0054] The round stock 10 having the covering 20 and having the depressions 14 that are not covered by the covering 20 is exposed to a second electrolyte 32 (cf. the method step [d.sub.1] in FIG. 1 or the method step [d.sub.2] in FIG. 2].

[0055] The depressions 14 that are provided so as to form the inscription and/or marking 16 that is optically different, in particular a different color, to the surface 12 are filled by this second electrolyte 32 (cf. the method step [e.sub.1] in FIG. 1 or the method step [e.sub.2] in FIG. 2. As a result, it is possible to fill the depressions 14 with black chrome, black nickel, black rhodium, black ruthenium, copper-tin alloy, copper-tin-zinc alloy or with gold, in particular hard gold.

[0056] The inscription and/or marking 16 can be formed by a code, in particular a barcode or bar code, for example by a continuous biunique binary barcode or bar code. For the purpose of optical position determination and/or path measurement, the code comprises an absolute code structure that represents the actual stroke or the actual position of the round stock.

[0057] There are various options with respect to supplying the first electrolyte 30 and/or the second electrolyte 32:

[0058] In the first exemplary embodiment in accordance with FIG. 1, the round stock 10 is placed or immersed in a bath or a solution of the first electrolyte 30 and/or the second electrolyte 32.

[0059] In the second exemplary embodiment in accordance with FIG. 2, the round stock 10 having the covering 20 is coated in the arrow direction in the tampon-galvanic process at least in the area of the surface 12 that is not covered by the covering 20 by an electrode that is supplied with the first electrolyte 30 and/or with the second electrolyte 32 for example by way of a hose line, said electrode being in particular an electrode that is immersed in the first electrolyte 30 and/or in the second electrolyte 32.

[0060] In so doing, the electrode that is functioning as an anode is embodied from a material that is non-soluble with respect to the electrolyte [0061] as at least one plate that is encased by at least one sponge, stocking, cloth, non-woven material or wadding tampon or [0062] as at least one rod that is encased by at least one sponge, stocking, cloth, non-woven material or wadding tampon.

LIST OF REFERENCE NUMERALS

[0063] 10 Round stock, in particular piston rod

[0064] 12 Surface of the round stock 10

[0065] 14 Depression in the surface 12

[0066] 16 Inscription and/or marking

[0067] 20 Cover, in particular a mask or template

[0068] 30 First electrolyte

[0069] 32 Second electrolyte