An accumulation conveyor is a specialized material transport mechanism that is used in applications where goods require queuing or accumulation at some point of the transport route. Similar in most respects to a conventional roller conveyor, the accumulation conveyor differs in that it includes mechanisms that allow sections of the conveyor to be slowed down or stopped completely to allow goods to collect at that point. Usually, this is achieved by breaking down the conveyor into short, individually driven sections that include sensors and drive clutches, which allows individual sections to be run, slowed down or stopped at will. This functionality is commonly used in situations where palleting, sorting or taping operations require goods to accumulate on the conveyor rather than to flow constantly.
Roller conveyors are commonly used material transport mechanisms in a large range of dispatch facilities. This mechanism typically consists of a steel framework with a series of cylindrical rollers arranged sequentially within its outer members. Generally, the rollers are positioned in such a way that they are in constant contact with one another. This allows a single driven roller to transfer its motion to all rollers in the series, thereby driving the entire conveyor. In this way, a load that has been placed on the conveyor at any point will be transported along the conveyor's entire length on the moving rollers.
This arrangement works well in situations where goods must move from one point to another without any stops for intermediate action to be taken. Where these stops are required, however, an accumulation conveyor typically is used. These machines are, in most respects, similar to their conventional siblings with a continuous run of rollers along the length of the conveyor. The major difference between the accumulation conveyor and conventional types is a series of sections or individual zones that are created along the conveyor route.
A single motor generally drives the entire conveyor, with each individual zone featuring two drive points, one at each end of the section. The first point, which is fitted with a remotely controlled clutch, drives that section, and the end drive point is used to transfer the drive to the next section. In this way, the entire accumulation conveyor is driven simultaneously with the ability — because of the clutches — to stop a specific section of the belt when required. The stops are achieved using movement or pressure sensors that are located at strategic points along the conveyor route. This allows goods on the belt to be queued at a set point when actions such as loading, palleting or taping of cartons is required.