SAFETY DEVICE FOR A MACHINE IN WHICH A FIRST MACHINE PART PERFORMS A WORKING MOVEMENT WITH RESPECT TO A SECOND MACHINE PART

摘要

A safety device for a machine, in which machine a first machine part having a leading edge performs a working movement towards a second machine part, comprises a plurality of optical safety barriers and an evaluation unit. The optical safety barriers move in the working movement simultaneously with the first machine part in such a manner that the safety barriers move in advance of the leading edge at various spaced dispositions. The optical safety barriers span a protective field that has a two-dimensional cross section. The evaluation unit is designed for generating a stop signal to stop the first machine part in dependence upon the optical safety barriers. Towards the end of the working movement, the optical safety barriers are held substantially stationary in the region of the second machine part. The optical safety barriers are deactivated one following the other before they are interrupted by the first machine part.