A treadmill is a device generally used for walking, running, or climbing while staying in the same place. Treadmills were introduced before the development of powered machines to harness the power of animals or humans to do work, often a type of mill operated by a person or animal treading the steps of a treadwheel to grind grain. In later times, treadmills were used as punishment devices for people sentenced to hard labour in prisons. The terms treadmill and treadwheel were used interchangeably for the power and punishment mechanisms.
Example of modern treadmill
Horses powering a threshing mill
Treadmill used to punish prisoners at Breakwater Prison, Cape Town
Treadmill test at the medical center of the Olympic village at the 1980 Summer Olympics
A conveyor belt is the carrying medium of a belt conveyor system. A belt conveyor system is one of many types of conveyor systems. A belt conveyor system consists of two or more pulleys, with a closed loop of carrying medium—the conveyor belt—that rotates about them. One or both of the pulleys are powered, moving the belt and the material on the belt forward. The powered pulley is called the drive pulley while the unpowered pulley is called the idler pulley. There are two main industrial classes of belt conveyors; Those in general material handling such as those moving boxes along inside a factory and bulk material handling such as those used to transport large volumes of resources and agricultural materials, such as grain, salt, coal, ore, sand, overburden and more.
These conveyor structures contain belts for moving bulk sulfur from railcars to storage piles and from the piles to ships.
Belt conveyor systems at a packing depot
Baggage handling belt conveyor system
Belt conveyor from an open-pit lignite mine in Bavaria