ca. 1386. A clock is a mechanical instrument rather than a true machine. Although this clock had iron gears, many machines of the early
Industrial Revolution used wooden parts until around 1800.
Ancient times Water wheels date to the Roman period and were used to grind grain and lift irrigation water. Water-powered bellows were in use on
blast furnaces in China in 31 AD. By the 13th century, water wheels powered
sawmills and
trip hammers, to pull cloth and pound flax and later cotton rags into pulp for making paper. Trip hammers are shown crushing ore in
De re Metallica (1555).
Clocks were some of the most complex early mechanical devices. Clock makers were important developers of
machine tools including gear and screw cutting machines, and were also involved in the mathematical development of gear designs. Clocks were some of the earliest mass-produced items, beginning around 1830. Water-powered bellows for blast furnaces, used in China in ancient times, were in use in Europe by the 15th century.
De re Metallica contains drawings related to bellows for blast furnaces including a fabrication drawing. Improved gear designs decreased wear and increased efficiency. Mathematical gear designs were developed in the mid 17th century. French mathematician and engineer
Desargues designed and constructed the first mill with
epicycloidal teeth ca. 1650. In the 18th century
involute gears, another mathematical derived design, came into use. Involute gears are better for meshing gears of different sizes than epicycloidal. By the late nineteenth century steam power was applied to threshing and steam tractors appeared. Internal combustion began being used for tractors in the early twentieth century. Threshing and harvesting was originally done with attachments for tractors, but in the 1930s independently powered
combine harvesters were in use. In the mid to late 19th century, hydraulic and pneumatic devices were able to power various mechanical actions, such as positioning tools or work pieces. Pile drivers and steam hammers are examples for heavy work. In food processing, pneumatic or hydraulic devices could start and stop filling of cans or bottles on a conveyor. Power steering for automobiles uses hydraulic mechanisms, as does practically all earth moving equipment and other construction equipment and many attachments to tractors. Pneumatic (usually compressed air) power is widely used to operate industrial valves.
Twentieth century By the early 20th century machines developed the ability to perform more complex operations that had previously been done by skilled craftsmen. After 1900 factories were
electrified, and electric motors and controls were used to perform more complicated mechanical operations. This resulted in mechanized processes to manufacture almost all goods.
Categories s, the left driving the right: Blue arrows show the contact forces between them. The force line (or
line of action) runs along a tangent common to both base circles. (In this situation, there is no force, and no contact needed, along the opposite common tangent not shown.) The involutes here are traced out in converse fashion: points (of contact) move along the
stationary force-vector "string" as if it was being unwound from the left
rotating base circle, and wound onto the right
rotating base circle. In manufacturing, mechanization replaced hand methods of making goods. Prime movers are devices that convert thermal, potential or kinetic energy into mechanical work. Prime movers include internal combustion engines, combustion turbines (jet engines), water wheels and turbines, windmills and wind turbines and steam engines and turbines. Powered transportation equipment such as locomotives, automobiles and trucks and airplanes, is a classification of machinery which includes sub classes by engine type, such as internal combustion, combustion turbine and steam. Inside factories, warehouses, lumber yards and other manufacturing and distribution operations,
material handling equipment replaced manual carrying or hand trucks and carts. A step beyond mechanization is
automation. Early production machinery, such as the glass bottle blowing machine (ca. 1890s), required a lot of operator involvement. By the 1920s fully automatic machines, which required much less operator attention, were being used.
Military usage The term is also used in the military to refer to the use of
tracked armoured vehicles, particularly
armoured personnel carriers, to move troops (
mechanized infantry) that would otherwise have marched or ridden trucks into combat. In military terminology,
mechanized refers to ground units that can fight from vehicles, while
motorized refers to units (
motorized infantry) that are transported and go to battle in unarmoured vehicles such as trucks. Thus, a towed artillery unit is considered motorized while a self-propelled one is mechanized. ==Mechanical vs human labour==