Patent ID: 6771363
Filing Date: 2004-08-03
Classification: B21D

Abstract:
A method for determining the bending angle of a sheet which has been bent along a bending line, comprising the steps of:a) generating at least two light beams; b) using these light beams to project two points or line segments onto a part of the sheet to be checked which lies on one side of the bending line, the beams forming an angle of incidence which is known in advance with the bending line of the sheet; c) imaging these points or line segments onto receiving means; d) determining the distance between the points or line segments which have been projected onto the receiving means; e) choosing two parallel detection planes extending parallel to the bending line and having a predetermined distance (d); f) orienting the light beams such that they lie in said parallel detection planes and have equal angles of incidence; and g) calculating the bending angle (&bgr;) from the projected distance (p) of the points projected on a sheet to be bent, the known angles (&agr;) of incidence of the beams, and the known distance (d) between the detection planes.