Crane is a kind of machine that can lift and move heavy objects horizontally. Unlike conveyor, crane can continuously lift and move bulk materials, such as grain and coal.
Brief introduction to the history and development of crane
As early as the first century, cranes were driven by running treadmills or large wheels operated by humans or animals. These early cranes consisted of a long wooden beam, called a suspender, which was connected with a rotating base, a rope connected to a pulley at the top of the suspender and a hook for lifting heavy objects.
An important development in crane design took place in the middle ages, when a horizontal arm called a boom was added to the boom, and the connection between the boom and the boom enabled it to rotate, thus increasing the range of motion.
Until the development of steam engine in the middle of the 19th century, cranes relied on the power of people or animals. By the end of the 19th century, internal combustion engines and electric motors were used to provide power for cranes. At this time, most cranes were made of steel rather than wood.
In the 1950s, due to the stronger steel and the increased demand for higher buildings, the development of cranes led to the long boom of cranes, which can be hung on small trucks or tracks.