Controlled flow gravity conveyor system and method

摘要

A gravity conveyor system is disclosed including a device for actively stopping the rotation of the conveyor rollers following disengagement with a conveyed article after it passes thereover and in advance of a next succeeding article. This allows each article to accelerate an engaged roller from a rest position so that precise transport control is effected without the use of positive drive mechanisms. Accurate control for throughput and accumulation results from cooperation between brake assemblies associated with each conveyor roller, a sensor assembly and a pneumatic control assembly, each combination of which acts in an operational zone. The rotation of the rollers is preferably stopped as a function of the sensed position of articles along the system. The pneumatic control assembly further includes a logic control mechanism that operates to selectively control the application of braking action either momentarily to allow continued controlled throughput or for a prolonged period of time to allow controlled accumulation. The gravity control system acts to practice a method for controlling the transport of articles without positive drive assistance in reliance on stopping the rotation of the rollers after an article has passed thereover and in advance of a next succeeding article. The apparatus and method further provide a device for stopping articles at the discharge point of the conveyor system without the need for extraneous stop mechanisms.