DEVICE FOR THE DETECTION OF HOLES IN CONTINUOUSLY-ADVANCING BANDS OF MATERIAL

摘要

The invention relates to a device for the detection of holes in continuously-advancing bands of material (arrow B). The inventive device is of the type that comprises a vertical structure (100) which is disposed on the path of the band of material, said material passing therethrough by means of a horizontal slit (110) which divides the structure into two parts, namely an upper frame (110a) and a lower frame (110b). Moreover, each of said frames opens onto the aforementioned slit (100) by means of opposing open windows. The upper frame (110a) is designed to support a first optical sub-assembly (200) which emits a light source in the direction of the band advancing therebelow, while the lower frame (110b) is designed to support a second optical sub-assembly (300) which receives the light from the first optical sub-assembly (200). The invention is characterised in that the optical emitting sub-assembly (200) comprises the stimulated emission of a laser radiation and in that the optical receiving sub-assembly (300) comprises photodiodes (310a and 310b) which are sensitive to the low light fluxes emitted by the laser radiation. The invention can be used for the detection of holes in bands of steel which are advancing continuously at great speed.