Patent Number: 
Section: description

The wall segment 10 shown in FIG. 1 is part of a protective device against the beams of a laser source 38 and comprises at least an inner wall 12 and a substantially parallel outer wall 14. The inner wall 12 and the outer wall 14 are metallic, preferably sheetmetal of iron or steel, the inner wall 12 being fitted at least on its side 18 facing the region subject to laser action, and preferably also on its outer side 20, with a coating 16. Preferably the coating 16 is a paint of high absorptivity, for instance black paint or the like. The side 22 of the outer wall 14 facing the inner wall 12 is only slightly absorbent. This low absorptivity or high reflectivity of the side 22 of the outer wall 14 is attained in practice by merely using a substantially untreated sheetmetal of iron or steel already comprising a reflecting surface and used as the outer wall 14. Clearly the side 22 of the outer wall 14 facing the inner wall 12 may be subjected to special treatment or processing to increase reflectivity. Preferably the side 20 of the inner wall 12 shall also be coated. In the embodiment of FIG. 2, a partition 24 uncoated on both sides is present in the gap between the inner wall 12 and the outer wall 14 and offers low absorptivity, ie high reflectivity. It is understood that the partition also may be coated on one or both sides with a highly absorbent coating of paint. Such different designs depend on the particular applications. In the embodiment of FIG. 3, two partitions 24, 26 are used, the partition 24 being uncoated, ie reflecting, and the partition 26 being coated, ie absorbent, in a special embodiment mode. In the embodiment of FIG. 4, again two partitions 24, 28 are present between the inner wall 12 and the outer wall 14 of the wall segment, in this case the partition 28 consisting of graphite or being a graphite-coated sheetmetal. The partition 24 on the other hand is uncoated and highly reflective. It is understood that changes in the above embodiments matching the particular applications can be used in the invention in arbitrary combinations. The basic concept of the invention is to generate particular gases, vapors or smoke, in the event of malfunction, by appropriately designing the wall segment 10. Individual walls fitted with a coating 16 are provided for that purpose. Illustratively the partition 26 may be fitted with a paint coat 30 at least on its inside 32 or also additionally on its outside. The spacings 32, 34 between the particular walls/partitions 12, 14, 24, 26, 28 substantially correspond to the diameter of the initial beam from the laser source 38. A space 34 or 36 between adjacent walls/partitions 12, 14, 24, 26, 28 of about 60 mm or more, was found practically appropriate. The distance 40 between the wall segment 10 and the laser source 38 should be about four-fold to five-fold the focal length of the laser optics. The end faces 42, 44 of the multi-shell wall segment 10 preferably are substantially closed on all sides. However, as schematically and illustratively shown in FIG. 4, boreholes 50 may be present, preferably in a vertical, upper segment, preferably in the vicinity of the end face 42. Illustratively the construction of the wall segment 10 is a framework, the frame consisting of steel beams or similar cross-sectionally contoured beams, and the walls/partitions 14, 16, 24, 26, 28 being affixed to the frame. Preferably two smoke or gas sensors 46, 48 connected to a control unit are mounted in the gap between the inner wall 12 and the outer wall 14 of the wall component 10 of the illustrative embodiment of FIG. 5. 10 wall segment 12 inner wall 14 outer wall 16 coating 18 side 20 side 22 side 24 partition (glossy) 26 partition (black) 28 partition (graphite) 30 coating of paint 32 side 34 spacing 36 spacing 38 laser source 40 distance 42 end face 44 end face 46 sensor 48 sensor 50 boreholes