28.1 INTRODUCTION
Basic layouts for material handling include,
- lines - stations arranged along a fixed part transfer path.
- batch - stations are grouped by function and batches of raw materials/WIP are brought in batches
- job shop - individual parts are carried through one or more stages by one worker
- job site - equipment is brought to the work
These transfer systems can also be categorized by their timing approach,
- synchronous - the entire line moves parts with a fixed period cycle. This is well suited to mass production of similar products.
- asynchronous - parts are moved as completed or needed. Often buffers are required, but this is more tolerant of problems than synchronous systems.
- continuous - the product flows by without stopping
Basic Requirements,
Random, independent movement of palletized workparts between workstations in the FMS
- pallets can flow from any station to any other
- parts are mounted in pallet fixtures
- pallets can move independently to avoid interference
Temporary storage or banking of workparts
- queues allow parts to wait for machines, thus increasing efficiency
Convenient access for loading and unloading workparts
- easy to do manual load/unload.
- automatic loading/unloading of parts at workstations
- can load/unload from either side of system
Compatible with computer control
Provision for future expansion
- modular extensions to system are desirable
Adherence to all applicable industrial codes
- allow unobstructed floor level access to each workstation
Operation in shop environment
- must be reliable when exposed to metal chips, cutting fluids, oil, dirt, etc.
Common type of Material handling systems
- power and free overhead conveyors
- floor "towline" systems
- robots (in a limited sense)
- indexing (geneva mechanism)
