1) Vertical lift module
A Vertical Lift Module, or VLM is a storage system that consists of two parallel columns each of which is divided into fixed shelf locations that can hold a single storage module such as a tray or tote. The shelving locations are single deep. A tray or tote is inserted, extracted and transported between storage levels and picking locations via an elevator-like device with an automatic shuttle that travels up and down within the space between the storage columns. See also Carousels and/or AS/RS .
Carousels are a technology used to store items for eventual picking or retrieval. There are two primary types of carousels and one related technology, all of which operate under some form of computer control. Since the late 1990s, carousels have been placed under the more general category of AS/RS. See also Horizontal Carousels , Vertical Carousels , Vertical Lift Modules and/or AS/RS .
3) Horizontal Carousels
As a storage device, a horizontal carousel consists of a fixed number of adjacent storage columns or bays that are mechanically linked to either an overhead or floor mounted drive mechanism to form a complete loop. Each column is divided into a fixed number of storage location or bins which in most applications are constructed of a welded wire frame. Loads consisting of containers or totes may be inserted and retrieved either manually or by an automatic inserter/extractor mechanism. However, rotation of the carousel, whereby a specific storage location is brought to the picking location, is almost always controlled automatically. See also Vertical Carousel , Vertical Lift Module , Rotary Rack , and/or AS/RS .