Chain wear monitoring device

Abstract

A conveyor or drive chain wear monitor includes two sensors spaced apart from one another a predetermined distance which is less than the distance between the adjacent measuring points on a chain. Two timers are provided, one of which is a chain speed timer and the other of which is the chain wear timer. The two timers are both controlled by the spaced sensors. The upstream sensor, as determined by the direction of travel of the chain, turns the speed timer on and the wear timer off. The downstream sensor turns the speed timer off and the wear timer on. Thus, when a measuring point passes the upstream sensor, the speed timer is turned on, and is not turned off again until the same measuring point passes the downstream timer. Knowing the distance between the upstream and downstream sensors, the computing module determines the speed at which the chain is moving as a function of the length of time, as determined by the speed timer, it took a measuring point on the chain to pass from the upstream sensor to the downstream sensor. When a measuring point passes the downstream sensor, it turns on the wear timer. The wear timer then remains on until a measuring point on the chain passes the upstream sensor. The wear timer will thus be turned on by a downstream measuring point, and turned off by the following upstream measuring point. Knowing the speed of the chain, the computing module can now determine the degree of wear on the chain as a function of the speed of the chain and the wear time which the wear timer is on, as compared to the baseline value for the same function when the chain is new.