Patent ID: 6047814
Filing Date: 2000-04-11
Classification: B65G

Abstract:
A method of monitoring a continuous revolving belt, said belt including a connecting section having a start and an end delimiting the length of said section viewed in the direction of movement of said belt, said start and said end assuming a pregiven desired distance s.sub.des therebetween measured along said section when said belt is in an unloaded, undamaged state, the method comprising the steps of:providing at least one start transponder mounted in or on said belt at said start of said connecting section and at least one end transponder mounted in or on said belt at said end of said connecting section;providing an external transmitter/receiver unit having an operative region wherein signals from said transponders can be received thereby;transmitting a first signal from said start transponder to said external transmitter/receiver unit at time point t.sub.0 when said start transponder passes through said operative region;transmitting a second signal from said end transponder to said external transmitter/receiver unit at time point t.sub.1 when said end transponder passes through said operative region;determining a time interval dt.sub.act =t.sub.1 -t.sub.0 in said external transmitter/receiver unit; and,determining whether a critical change in length of said connecting section has occurred based on said time span dt.sub.act.