With gradual improvement and promotion of steam engine, electric motors and other power machinery, modern crushing machines were created. Steam-driven roller crusher was appeared in 1806; In 1858, American Blake invented jaw crushers to break rock; in 1878 gyratory crusher got good development in USA, whose productivity is higher than the jaw crushers with intermittent crushing action; 1895, another American William invented the lower energy consumption impact.
Americans EW Black designed and manufactured the first jaw crusher in the world, with the structure of double toggle plate (simple swing). With the advantage of simple structure, easy manufacture, reliable, easy maintenance, small size and height, today they are still widely used to crush all kinds of hard, medium hard, soft ore and various materials, such as various minerals, solvents, slag, building stone, marble etc.
The working Principle of Jaw crushers is: the motor transmits power through belt, drives the moving jaw to do periodic motion towards the fixed jaw by the eccentric shaft. The angle between toggle plate and moving jaw plate increases when moving jaw moves. So the moving jaw moves towards the fixed jaw. The stuff will be crushed in this process. The angle between toggle plate and moving jaw decreases when moving jaw moves down, the moving jaw moves leaves fixed jaw by pulling rod and spring, the final crushed stuff will be discharged from the outlet.
Until 1980s, the feed size of large jaw crushing with the capacity of 800TPH has reached to 1800 mm. usually jaw crusherss are divided into single and double toggle plates models. The movable jaw plate of the former one only makes simple arc swing when works, it is also known as simple swing jaw crushers; the latter also do up and down movement besides arc movement, which is also known as complex swing jaw crushers.