Laser-protective wall element for a housing in laser machining stations

• US 8,829,889 B2
• Filed: 08/07/2008
• Issued: 09/09/2014
• Est. Priority Date: 08/08/2007
• Status: Active Grant

• Current Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Original Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Inventors: Hannweber, Jan, Kuehn, Stefan, Bretschneider, Sven, Melde, Michael
• Primary Examiner(s): ISLA RODAS, RICHARD
• Application Number:
  US12/672,428
• Publication Number:
  US 20110260737A1
• Time in Patent Office: 2,224 Days
• Field of Search: 219/121.86, 250/515.1
• US Class Current: 324/96
• CPC Class Codes: B23K 26/706 Protective screens
• CPC Class Codes: F16P 1/06 specially designed for welding

Abstract

A laser protective wall element for a housing in laser machining stations with which increased protection, in particular for the eyes of living beings, can be achieved. In a laser protective wall element for a housing at laser machining stations, an intermediate layer is present which has hot conductor properties. The intermediate layer can be formed between electrically conductive plate-like elements, an electrically conductive plate-like element and an electrically conductive coating or also two electrically conductive layers or can be arranged there. The electrically conductive plate-like elements, the coating and/or the layers are connected to an electrical voltage source as well as a measuring instrument which detects electrical current, electrical resistance and/or electrical capacity and whose measured signal change can be used for the condition monitoring of the laser protective wall element.

Claims

1. A laser protective wall element for a housing in a laser machining station, comprising:

first and second electrically conductive plate-like elements; and

an intermediate layer arranged between the first and second electrically conductive plate-like elements separating them from one another, the intermediate layer having electrical hot conductor properties,

wherein the first and second electrically conductive plate-like elements are connected to an electrical voltage source and a measuring instrument which detects a measured signal change of at least one of an electrical current, an electrical resistance and an electrical capacity, and

wherein a condition of the laser protective wall element is being monitored as a function of the measured signal change;

a laser generating unit configured to generate a laser beam; and

an electronic evaluation and control unit configured to generate at least one of a deactivation signal for the laser generating unit and a warning signal to take place when the measured signal change exceeds a predetermined threshold value.

2. The laser protective wall element of claim 1, further comprising:

a plate-like outer wall element parallel to one of the first and second electrically conductive plate-like elements and a coated plate-like element.

3. The laser protective wall element of claim 2, wherein the plate-like outer wall element is separated from an adjacent one of at least one of the first and second plate-like elements by one of a space and a dielectric separating layer.

4. The laser protective wall element of claim 1, wherein the intermediate layer has a constant layer thickness and consistency over the total surface.

5. The laser protective wall element of claim 1, wherein the intermediate layer is a binder which has hot conductor properties and with which the first and second plate-like elements are connected to one another with material continuity.

6. The laser protective wall element of claim 1, wherein the intermediate layer is formed by at least one of a metal oxide, a mixture of metal oxides and a polymer having hot conductor properties.

7. The laser protective wall element of claim 1, wherein the intermediate layer is formed by a binder including one of aluminum oxide and magnesium oxide.

8. The laser protective wall element of claim 1, wherein the intermediate layer is formed by a polycrystalline semiconductor of at least one sinterable metal oxide.

9. The laser protective wall element of claim 1, wherein the intermediate layer is formed with one of Fe₂O₄ and Zn₂TiO₄.

10. The laser protective wall element of claim 1, wherein the first and second electrically conductive plate-like elements are separated from one another by the intermediate layer and a dielectric support structure.

11. The laser protective wall element of claim 10, wherein the support structure is one of a fabric and a knitted fabric which is formed with fibers and which is interspersed with the substance forming the intermediate layer.

12. The laser protective wall element of claim 1, further comprising:

at least one further laser protective wall element, the laser protective wall element and the at least one further laser protective wall element being arranged at least one of next to one another and above one another with outer margins of the laser protective wall element and the at least one further laser protective wall element that are adjacent one another overlapping.

13. The laser protective wall element of claim 1, wherein the intermediate layer has a specific electrical resistance of at least 10¹⁰ Ω

cm at a temperature of 20°

C. which reduces to a value of at least 10⁸ Ω

cm at a temperature of 600°

C.

14. The laser protective wall element of claim 1, wherein one of the first and second plate-like elements is formed of one of iron and an iron alloy and includes a bluing as the intermediate layer.

15. The laser protective wall element of claim 1, wherein the first and second plate-like elements are of one of aluminum and an aluminum alloy and the intermediate layer is provided with an anodized layer.

16. The laser protective wall element of claim 1, wherein the coating is formed with an electrically conductive lacquer.

17. The laser protective wall element of claim 1, wherein the electrically conductive layers and the intermediate layer are formed on a window element with a thickness so that they are optically transparent in the wavelength range of visible light.