Patent ID: 6043889
Filing Date: 2000-03-28
Classification: G01B

Abstract:
A rail misalignment detection system for use in verifying whether a first rail on a moveable span of a rail bridge extends within an acceptable range of misalignment with a second rail on a fixed span of the rail bridge; said detection system comprising:a) a transmitter mounted on a first of said moveable span and said fixed span of said rail bridge and positioned to direct a beam of collimated light toward said second of said moveable span and said fixed span;b) a receiver mounted on a second of said moveable span and said fixed span of said rail bridge and including a photo cell; said receiver and said transmitter mounted relative to said first and second rails and to each other such that when said first and second rails extend within the acceptable range of misalignment said beam strikes said photo cell to a sufficient degree to activate said photocell, and when said first and second rails extend beyond the acceptable range of misalignment said beam does not strike said photocell to a sufficient degree to activate said photocell; andc) said photocell communicating with a signal system for said bridge such that deactivation of said photocell changes an output from said signal system from indicating that said bridge is safe to cross to indicating that said bridge is not safe to cross.