Compound lever the force of pushing back the stick to the levers and they rub against the wheels, using friction to slow and eventually stop the train. These are everyday applications of this mechanism. A piano key is a compound lever of the first-class, since the fulcrum is between the weight to be moved and the power. The purpose of this lever is to translate a small movement (depression of the key) into a larger and fast movement of the hammer on the strings. The quality of the resulting tone depends on whether the final speed is brought about by gradual or
Lever escapement in alarm clocks, kitchen timers, mantel clocks and, until the late 1970s, cheap watches, called the "Roskopf", "pin-lever", or "pin-pallet escapement" after Georges Frederic Roskopf, who invented it in 1867. It functions similarly to the lever, except that the lever pallet jewels are replaced by vertical metal pins. In a lever escapement, the pallets have two angled faces, the locking face and the impulse face, which must be carefully adjusted to the correct angles. In the pin pallet escapement, these two faces are designed into the shape of the escape wheel teeth instead, eliminating complicated adjustments. The pins are located