What is a paternoster or circulating storage system?
Paternoster or circulating storage system: Not only in demand as an elevator, but also ideal for storing small parts
Everyone who took a step into offices or administrative buildings in the 80s or 90s knows the so-called paternoster elevator. This is also the origin of the unflattering paraphrase as "civil servant lifter". But first things first: The paternoster is a classic passenger circulating elevator, typically accommodating up to two people per car. The special feature of this elevator system is the fact that the respective individual cabs (suspended from chains) can be controlled in continuous circulation. One and the same elevator car constantly changes between two elevator shafts by means of turning point disks - one time it goes up, another time it goes down.
What does the paternoster have to do with intralogistics? Quite a lot, as proLogistik will explain in more detail. But first of all, let's take a look at the basics of the paternoster elevator, before we take a closer look at the logistical components.
Basics explained simply: paternoster as a passenger elevator
The term as such derives from Latin and means, mutatis mutandis, "our father", it was used over time, especially by miners, as a name for circulating elevators, which are similar in their arrangement to the rosary beads. The paternoster elevator is designed so that people can quickly pass over individual floors without waiting and in both directions. A look at the transport speed per person in particular makes it clear why this principle was increasingly used in public buildings, especially in the post-war years.
However: Paternoster elevators were only put into operation in West Germany until 1974. Due to fire protection regulations and other rules, only about 200 paternosters exist in Germany. However, the principle is ideally suited for handling small parts, as we will explain in more detail in the next paragraph.
The Paternoster Warehouse (PNL): A vertical carousel for maximum performance in limited space
A circulating storage system in the form of a paternoster is particularly in demand for small parts warehouses, because the advantages are obvious. On the one hand, space can be optimally utilized by building "upwards". Vertical shelves are designed to store various small parts in a space-saving manner. On the other hand, the warehouse operator's search time is reduced to a minimum, and travel times have also been completely eliminated due to the goods-to-man principle.
Shelving systems such as the paternoster can be tailored to the specific needs of the company, for example, specifically for card index boxes or as a tiered paternoster for shipping handling. It would also be conceivable to design the rail guide horizontally (so-called silo paternoster) in order to make full use of storage space as far as possible.
Note: A paternoster warehouse is based on the goods-to-man principle and facilitates the picking of small parts, which are made accessible quickly and compactly via so-called removal openings. It enables efficient storage because it can be directly controlled, ensures high speed of circulation and increases the storage area even when space is limited.
Structure of a paternoster warehouse
To get a better idea of how a paternoster works, let's outline the structure of this carousel system in more detail. The particular advantage is that an individual design to the requirements of the bearing is possible in practically every case. Individual, customer-specific solutions can therefore be realized at any time.
The most important facets of the paternoster bearing are summarized below:
- The basic principle is based on the paternoster elevator, the stored goods are delivered directly to the operator (goods-to-man principle), not vice versa.
- Vertically arranged, all-round shelves can be loaded and unloaded with goods via a conveniently accessible operating window. Each storage compartment is assigned a unique number, they rotate within the closed system.
- The paternoster can be used with open fronted storage bins, for example, to efficiently handle small parts via small parts bins. They can be stored loose and without packaging.
Important: A paternoster bearing as a recirculating bearing system cannot be extended at will. This is due to the rigid outer shell. However, the inner workings of the storage system can be optimized, for example, to increase picking performance on the basis of a higher circulation speed. Warehouse management according to the Fifo principle ("First in, first out") as well as according to the Lifo principle ("Last in, first out") can be realized with a carousel à la paternoster.