Loading-unloading Machine

(or loader-unloader), an intermittent-operation or continuous-operation hoisting and conveying machine used to perform loading-unloading, conveying, and stacking operations with bulk and unit (piece) goods. The machines frequently include independent hoists or conveying machines or units.

Loading-unloading machines may be stationary, mobile, or self-propelled (with wheels or crawlers), depending on the operations performed. They may be driven by internal-combustion engines or electric motors, whose power is transmitted to the working and drive elements through mechanical or hydraulic transmissions. Loading-unloading machines are divided into two basic groups: loaders, which primarily perform loading operations but are often also used for conveying goods, and unloaders, which are generally used only for unloading bulk goods. The term “loading-unloading machine” is also used in a broader sense to apply to all machines that can be used in loading-unloading work, such as cranes, portable and mobile conveyors, power shovels, and scrapers.

A type of loading-unloading machine is the load-haul-dump vehicle, which is used in underground ore mining.