Crane Development origin: history. Zhejiang small amplitude 20 t crane, operations difficult. To the 15th century, Italian invented the jib crane, to solve this problem. This crane has roots inclined cantilever arm equipped with a pulley top 20 t crane manufacturers, can lift can be rotated. But not until the 18th century, 20-ton crane manufacturer, all kinds of lifting machinery are also used by humans to human, animal powered on starting weight, range and efficiency is very limited. Crane Development origin: history. Early 20th century, Europe began to use the tower crane. Crane hoisting mechanism mainly run institutions, luffing mechanism, slewing mechanism and metal structure. Hoisting mechanism is the basic working body of the crane, mostly by hanging system and winch composition, but also lift weights through the hydraulic system. 20 t crane manufacturers, 20 t crane, provided by the Henan Yongchang Yongchang Machinery Construction Machinery Co. Henan Yongchang Engineering Machinery Co., Ltd. (www.tadanocrane.net) strong, credible, Anyang, Henan Province in other industries has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead Yongchang machinery into the brilliant and you work for a better future!