Patent ID: 8446247
Filing Date: 2013-05-21
Classification: F16P,G01V

Abstract:
1. A safety system for detecting the presence of an undesired object in a safety area having a conveyor for conveying materials defining a conveying path extending through said safety area system comprising: a first pair of distance measuring sensors disposed on opposed sides of the conveying path, the first pair of distance measuring sensors defining a first sensor field between said first pair of distance measuring sensors; a second pair of distance measuring sensors disposed on opposed sides of the conveying path, the second pair of distance measuring sensors defining a second sensor field between said second pair of distance measuring sensors; an electronic control device operatively coupled to the sensors; wherein the distance measuring sensors are configured to transmit signals related to measured distances to the electronic control device; and wherein the electronic control device is provided with programming instructions for determining a horizontal dimension of objects disposed in the first sensor field and the second sensor field along a substantially horizontal direction that is non-parallel to the conveying path based at least in part on the signals related to measured distances, and configured to initiate a conveyor-stopping sequence based at least in part on the determined horizontal dimension of the objects; wherein the electronic control device is configured to compare a first measured distance defined by said first sensor field and a second measured distance defined by said second sensor field and said conveyer-stopping sequence is responsive to the presence of the undesired object in at least one of: said first sensor field, said second sensor field; wherein the presence of the undesired object in at least one of said first sensor field and said second field is determined when a distinction between said first measured distance and said second measured distance is sufficient based on the comparison.