Patent ID: 8028817

Claim:
A conveyor comprising a plurality of zones arranged in a row in a conveying direction, each of the zones having at least one driving motor for generating power to convey articles in the zone and an article sensor for detecting an article in the zone and for transmitting a signal indicating presence or absence of an article, wherein the conveyor further comprises (1) a measuring structure through which either an interval between adjacent articles in the conveying direction or a difference of time points when adjacent articles in the conveying direction pass the article sensor acting as a benchmark is measured and (2) a motor controller for each of the zones and for varying a rotational speed of the driving motor, wherein the measuring structure measures the interval or the difference upon reception of signals from the sensor, and wherein the motor controller either accelerates or slows down the rotational speed of the driving motor in a zone in which at least one of the articles is placed so as to either increase or decrease a speed for conveying articles, thereby adjusting the interval between the articles, the conveyor being adapted to accelerate the rotational speed of the driving motor relating to an article adjacent to and behind another article in the conveying direction in a case where either the interval or the difference is beyond a predetermined upper limit so as to thereby adjust the interval by narrowing the interval, the conveyor being adapted to slow down the rotational speed of the driving motor relating to the article in a case where either the interval or the difference is below a predetermined lower limit so as to thereby adjust the interval by widening the interval.