Sakichi Toyoda (–L“c �²‹g Toyoda Sakichi, February 14, 1867 – October 30, 1930) was an inventor and industrialist. He was born in Kosai, Shizuoka. The son of a poor carpenter, Toyoda is referred to as the "King of Japanese Inventors". He is often referred to as the father of the Japanese industrial revolution. He is also the founder of Toyota Industries Co., Ltd.He invented numerous weaving devices. His most famous invention was the automatic power loom in which he implemented the principle of Jidoka (autonomous automation). The principle of Jidoka, which means that the machine stops itself when a problem occurs, became later a part of the Toyota Production System.Toyoda developed the concept of 5 Whys: When a problem occurs, ask 'why' five times to try to find the source of the problem, then put into place something to prevent the problem from recurring. This concept is used today as part of applying Six Sigma methodologies to solve problems, improve quality, and reduce costs.

A cylinder head sliced in half shows two overhead camshafts—one above each of the two valves.Overhead camshaft (OHC) valvetrain configurations place the camshaft within the cylinder heads, above the combustion chambers, and drive the valves or lifters directly instead of using pushrods. When compared directly with pushrod (or I-Head) systems with the same number of valves, the reciprocating components of the OHC system are fewer and in total will have less mass. Though the system that drives the cams may become more complex, most engine manufacturers easily accept the added complexity in trade for better engine performance and greater design flexibility. The OHC system can be driven using the same methods as an I-Head system, these methods may include using a timing belt, chain, or in less common cases, gears.Many OHC engines today employ Variable Valve Timing and multiple valves to improve efficiency and power. OHC also inherently allows for greater engine speeds over comparable cam-in-block designs.There are two overhead camshaft layouts:

 + Single Overhead Camshaft (SOHC)

+ Double Overhead Camshaft (DOHC)