Lever Lever A lever ( or ) is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or fulcrum. A lever is a rigid body capable of rotating on a point on itself. On the basis of the location of fulcrum, load and effort, the lever is divided into three types. It is one of the six simple machines identified by Renaissance scientists. A lever amplifies an input force to provide a greater output force, which is said to provide leverage. The ratio of the output force to the input force is the mechanical advantage
Lever escapement symmetrically on the lever, making beat adjustment simpler. Watches that used these escapements were called "pin lever watches", and have been superseded by cheap quartz watches. One recent trend in escapement design is the use of new materials, many borrowed from the semiconductor fabrication industry. A problem with the lever escapement is friction. The escape wheel tooth slides along the face of the pallet, causing friction, so the pallets and teeth must be lubricated. The oil eventually thickens, causing inaccuracy, and requiring cleaning and reoiling of the movement about every 4 years. A solution is to make the escape wheel