The beak would engage an escapement hopper attached to the keyframe.

The escapement hopper pulled down on the beak as it rose, in turn causing the hammer ( the other end of the lever ) to fly upward and strike the key.

It was driven by a large waterwheel, chain drive, and escapement mechanism.

Another example of his inventive genius was the grasshopper escapement – a control device for the step-by-step release of a clock's driving power.

Developed from the anchor escapement, it was almost frictionless, requiring no lubrication because the pallets were made from the wood lignum vitae.

This mechanism required less power, caused less friction and was accurate enough to measure seconds reliably as one-sixtieth of a minute than the older verge escapement.

Henry Sully, writing in Paris in 1717, described the anchor escapement as " an admirable invention of which Dr. Hooke, formerly professor of geometry in Gresham College at London, was the inventor.

The pin-lever escapement ( called the Roskopf movement after its inventor, Georges Frederic Roskopf ), which is a cheaper version of the fully levered movement, was manufactured in huge quantities by many Swiss manufacturers as well as Timex, until it was replaced by quartz movements.

This was obtained by means of a plug tree which was a beam suspended vertically alongside the cylinder from a small arch head by crossed chains its function being to open and close the valves automatically when the beam reached certain positions, by means of tappets and escapement mechanisms using weights.

To govern the intermittent movement of the film in the camera, allowing the strip to stop long enough so each frame could be fully exposed and then advancing it quickly ( in about 1 / 460 of a second ) to the next frame, the sprocket wheel that engaged the strip was driven by an escapement disc mechanism — the first practical system for the high-speed stop-and-go film movement that would be the foundation for the next century of cinematography.

The escapement mechanism was in the form of a constant-head system, while heavy floats were used as weights.

However his greatest innovation was the invention of the Graham dead-beat escapement around 1715.

In Song China, an astronomical clock tower was designed by Su Song and erected at Kaifeng in 1088, featuring a liquid escapement mechanism.

This best known model was first patented in 1875, and now the battery was replaced by a mechanical escapement.

The grasshopper escapement was used in a few regulator clocks built during Harrison's time, and a few others over the years, but has never seen wide use.

The grasshopper escapement was invented by John Harrison who used it in his regulator clocks, and also in the first three of his marine timekeepers, H1-H3.

This proved to be unreliable, needing repeated fixes for which Harrison was not paid, so around 1722 he modified the escapement by putting a hinge in the middle of each arm of the anchor.

The small movement of the pallet on its hinge involves far less friction than the sliding contact in a conventional escapement ; it does not need lubrication and there is so little wear that Harrison was able to make his pallets from wood.

Around the same time as Harrison invented the grasshopper, George Graham introduced his deadbeat escapement which reduced this effect, and this practical and simple escapement was to become standard in precision regulator clocks.

Because of these various idiosyncrasies, the grasshopper escapement was never used widely.

A unique public clock built as a tribute to John Harrison's grasshopper escapement, the Corpus Clock, was unveiled at Corpus Christi College, Cambridge University, in Cambridge, England on September 19, 2008.

Feeling that Harrison's escapement was not well enough known, the clock's grasshopper escapement is exposed on the top of the clock, built in the form of a demonic grasshopper called the " Chronophage " or " time eater ", which rhythmically opens and closes its jaws, representing time being devoured.

In this escapement, the pendulum is driven by two hinged arms ( pallets ).

The repeater RBG is usually made of wood, and has a plastic firing mechanism, consisting of a toothed wheel onto which the bands are hooked, and a sprung trigger / escapement that releases the wheel by one notch, releasing a rubber band every time the trigger is pulled .< nowiki ></ nowiki >

In 1696, Etienne Loulié first successfully used an adjustable pendulum in the construction of the first mechanical metronome ; however, his design did not produce any sound and did not include an escapement with which to keep the pendulum in motion.

Often power for the device is stored within it, via a winding device that applies mechanical stress to an energy-storage mechanism such as a mainspring, thus involving some form of escapement ; in other cases, hand power may be utilized.

The duplex is a frictional rest escapement ; the balance is never totally free from the escapement because of the tooth resting against the roller.

Its advantages are ( 1 ) the balance wheel is more " detached " or independent than in the cylinder or duplex escapements ; it is only in contact with the lever during the short impulse period when the balance swings through its center position, increasing accuracy, and ( 2 ) it is a self-starting escapement, so if the watch is shaken so that the balance wheel stops, it will automatically start again.

The anchor escapement consists of two parts ; the escape wheel, which is a vertical wheel with pointed teeth on it rather like saw teeth, and the anchor, shaped vaguely like a ship's anchor, which swings back and forth on a pivot just above the escape wheel.

* It is a frictional escapement ; the pendulum is always being pushed by an escape wheel tooth throughout its cycle, and never allowed to swing freely.

* It is a recoil escapement as mentioned above ; the momentum of the pendulum pushes the escape wheel backward during part of the cycle.

One way to tell whether an antique watch has a verge escapement is to observe the second hand closely ; if it moves backward a little during each cycle, the watch is a verge.

The reliability of the modern lever escapement depends upon draw ; the pallets are angled so that the escape wheel must recoil a small amount during the unlocking.

In 1821, Sébastien Érard invented the double escapement action, which incorporated a repetition lever ( also called the balancier ) that permitted a note to be repeated even if the key had not yet risen to its maximum vertical position.

An escapement, part of every mechanical clock, is the mechanism that causes the clock's gears to move forward by a fixed distance at regular intervals and also gives the pendulum ( or the balance wheel ) periodic pushes to keep it swinging.

The paper placement is achieved by rolling the paper onto an internal drum, unrolling it when the user presses a line-feed key, and using a clock-like escapement to move an embossing carriage over the paper.

It featured four stepper motors ( 1 ) to move the film across, ( 2 ) to move the type disk, ( 3 ) to advance the film to the next line, and ( 4 ) to set the size of one unit of escapement.

Since the escapement doesn't have a recoil period when the tooth's force opposes the direction of the pendulum's motion, increased force causes the pendulum to swing in a wider arc, as well as move faster.

* The escapement has " recoil ", meaning that the momentum of the foliot or pendulum pushes the crown wheel backward momentarily, causing the clock's wheel train to move backward, during part of its cycle.

When a key is pressed, the corresponding escapement is actuated, which releases a matrix from the magazine.

The importance of the escapement in the history of technology is that it was the key invention that made the all-mechanical clock possible.

The three black lifting pins are key to the operation of the escapement.

The lever escapement is a key component of the typical movement found in most mechanical wristwatches, pocket watches and many small mechanical non-pendulum clocks.