The coaxial escapement is a type of modern watch escapement mechanism invented by English watchmaker George Daniels in 1976 and patented in 1980. It is one of the few watch escapements which have been invented in modern times and is used in most of the mechanical watch models currently produced by Omega SA.
During the quartz crisis, English watchmaker George Daniels accepted a commission from American industrialist and watch collector Seth G. Atwood to create a timepiece that would fundamentally improve the performance of mechanical watches. [1] As a result, Daniels invented the coaxial escapement in 1974 and patented it in 1980. [2] [3] The Atwood watch for Seth G. Atwood was completed in 1976. [4]
The coaxial escapement is a modification of the lever escapement with some features of the detent escapement. One of the few advances in escapement design which have been adopted since the invention of the lever escapement by Thomas Mudge in the 18th century, the coaxial escapement functions with a system of three pallets that separate the locking function from the impulse, avoiding the sliding friction of the lever escapement. This makes lubrication of the pallets theoretically unnecessary [5] [6] and thereby minimizes one of the shortcomings of the traditional lever escapement. In practice, a small amount of lubrication is used on the locking and impulse surfaces of the pallet stones, reportedly to minimize impact corrosion. [7]
The critical virtue of the Daniels escapement is the virtual elimination of the sliding friction component; i.e., the sliding of the pallet stones over the teeth of the escapement gear. What little sliding friction remains is due to the impossibility of maintaining an exact tangential geometry throughout the duration of an impulse. [8]
By utilizing radial friction instead of sliding friction at the impulse surfaces the coaxial escapement significantly reduces friction, theoretically resulting in longer service intervals (though many factors influence this including lubricant aging) and greater accuracy over time.
The escapement was commercialized in 1999 by Omega SA when it introduced the first mass-produced watch incorporating the technology. [9] It is the only escapement other than the Swiss lever escapement that is produced on an industrial scale. When it first came to the market as the Caliber 2500, it had an oscillation rate of 28,800 beats per hour (8 beats per second), considered a "hi-beat" movement. But the rate was reduced to 25,200 beats per hour (7 beats per second) in the Caliber 2500C. "While Daniels has recognized the advantages of higher beat movements, he has also noted that they aggravate the problem of sliding friction in the escapement (at the escape teeth and pallets). Higher beat movements produce increased speed and pressure at these critical surfaces." [10]
The grasshopper escapement is a low-friction escapement for pendulum clocks invented by British clockmaker John Harrison around 1722. An escapement, part of every mechanical clock, is the mechanism that gives the clock's pendulum periodic pushes to keep it swinging, and each swing releases the clock's gears to move forward by a fixed amount, thus moving the hands forward at a steady rate. 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 term "grasshopper" in this connection, apparently from the kicking action of the pallets, first appears in the Horological Journal in the late 19th century.
An escapement is a mechanical linkage in mechanical watches and clocks that gives impulses to the timekeeping element and periodically releases the gear train to move forward, advancing the clock's hands. The impulse action transfers energy to the clock's timekeeping element to replace the energy lost to friction during its cycle and keep the timekeeper oscillating. The escapement is driven by force from a coiled spring or a suspended weight, transmitted through the timepiece's gear train. Each swing of the pendulum or balance wheel releases a tooth of the escapement's escape wheel, allowing the clock's gear train to advance or "escape" by a fixed amount. This regular periodic advancement moves the clock's hands forward at a steady rate. At the same time, the tooth gives the timekeeping element a push, before another tooth catches on the escapement's pallet, returning the escapement to its "locked" state. The sudden stopping of the escapement's tooth is what generates the characteristic "ticking" sound heard in operating mechanical clocks and watches.
A jewel bearing is a plain bearing in which a metal spindle turns in a jewel-lined pivot hole. The hole is typically shaped like a torus and is slightly larger than the shaft diameter. The jewels are typically made from the mineral corundum, usually either synthetic sapphire or synthetic ruby. Jewel bearings are used in precision instruments where low friction, long life, and dimensional accuracy are important. Their largest use is in mechanical watches.
Omega SA is a Swiss luxury watchmaker based in Biel/Bienne, Switzerland. Founded by Louis Brandt in La Chaux-de-Fonds in 1848, the company formerly operated as La Generale Watch Co. until incorporating the name Omega in 1903, becoming Louis Brandt et Frère-Omega Watch & Co. In 1984, the company officially changed its name to Omega SA and opened its museum in Biel/Bienne to the public. Omega is a subsidiary of The Swatch Group.
In horology, the anchor escapement is a type of escapement used in pendulum clocks. The escapement is a mechanism in a mechanical clock that maintains the swing of the pendulum by giving it a small push each swing, and allows the clock's wheels to advance a fixed amount with each swing, moving the clock's hands forward. The anchor escapement was so named because one of its principal parts is shaped vaguely like a ship's anchor.
The vergeescapement is the earliest known type of mechanical escapement, the mechanism in a mechanical clock that controls its rate by allowing the gear train to advance at regular intervals or 'ticks'. Its origin is unknown. Verge escapements were used from the late 13th century until the mid 19th century in clocks and pocketwatches. The name verge comes from the Latin virga, meaning stick or rod.
A balance wheel, or balance, is the timekeeping device used in mechanical watches and small clocks, analogous to the pendulum in a pendulum clock. It is a weighted wheel that rotates back and forth, being returned toward its center position by a spiral torsion spring, known as the balance spring or hairspring. It is driven by the escapement, which transforms the rotating motion of the watch gear train into impulses delivered to the balance wheel. Each swing of the wheel allows the gear train to advance a set amount, moving the hands forward. The balance wheel and hairspring together form a harmonic oscillator, which due to resonance oscillates preferentially at a certain rate, its resonant frequency or "beat", and resists oscillating at other rates. The combination of the mass of the balance wheel and the elasticity of the spring keep the time between each oscillation or "tick" very constant, accounting for its nearly universal use as the timekeeper in mechanical watches to the present. From its invention in the 14th century until tuning fork and quartz movements became available in the 1960s, virtually every portable timekeeping device used some form of balance wheel.
In horology, a tourbillon is an addition to the mechanics of a watch escapement to increase accuracy. It was developed around 1795 and patented by the Swiss-French watchmaker Abraham-Louis Breguet on June 26, 1801. In a tourbillon the escapement and balance wheel are mounted in a rotating cage, with the goal of eliminating errors of poise in the balance giving a uniform weight.
The pallet fork is a component of the lever escapement of a mechanical watch. The pallet fork and the lever form one component that sits between the escape wheel and the balance wheel. Its purpose is to lock the escape wheel, and release it one tooth at a time at each swing of the balance wheel, and also give the balance wheel small pushes to keep it going.
The lever escapement, invented by the English clockmaker Thomas Mudge in 1754, is a type of escapement that is used in almost all mechanical watches, as well as small mechanical non-pendulum clocks, alarm clocks, and kitchen timers.
A Roskopf, pin-lever, or pin-pallet escapement is an inexpensive, less accurate version of the lever escapement, used in mechanical alarm clocks, kitchen timers, mantel clocks and, until the 1970s, cheap watches now known as pin lever watches. It was patented by German watchmaker Georges Frederic Roskopf in 1867, suggested to Roskopf by Jules Grossmann.
George Daniels, CBE, FBHI, FSA, AHCI was an English horologist who was considered by some to be one of the best in the world in the field of luxury mechanical watches and timepieces during his lifetime. He was a watchmaker who built complete watches by hand. But it was his creation of the coaxial escapement for which he is most remembered. The movement, which theoretically removed the need to add a lubricant, has been used by Omega in most of their collections since 1999 with the exception of the Speedmaster Moonwatch.
The British Horological Institute (BHI) is the representative body of the horological industry in the United Kingdom. It was founded by a group of clockmakers in 1858, and has its current premises at Upton Hall in Nottinghamshire, which includes a museum of clock history.
A mechanical watch is a watch that uses a clockwork mechanism to measure the passage of time, as opposed to quartz watches which function using the vibration modes of a piezoelectric quartz tuning fork, or radio watches, which are quartz watches synchronized to an atomic clock via radio waves. A mechanical watch is driven by a mainspring which must be wound either periodically by hand or via a self-winding mechanism. Its force is transmitted through a series of gears to power the balance wheel, a weighted wheel which oscillates back and forth at a constant rate. A device called an escapement releases the watch's wheels to move forward a small amount with each swing of the balance wheel, moving the watch's hands forward at a constant rate. The escapement is what makes the 'ticking' sound which is heard in an operating mechanical watch. Mechanical watches evolved in Europe in the 17th century from spring powered clocks, which appeared in the 15th century.
Georges Frederic Roskopf, the inventor of the pin-pallet escapement, was born in Germany and became a naturalized Swiss citizen.
In horology, a wheel train is the gear train of a mechanical watch or clock. Although the term is used for other types of gear trains, the long history of mechanical timepieces has created a traditional terminology for their gear trains which is not used in other applications of gears.
Roger W. Smith OBE is a British independent watchmaker. Smith was a Bronze Medallist of the British Horological Institute.
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The échappement naturel was the invention of Abraham-Louis Breguet, one of the most eminent watchmakers of all time. Following the introduction of the detent chronometer escapement with a temperature compensated balance, very close rates could be achieved in marine chronometers and to a lesser degree in pocket chronometers. This achievement was due, other things being equal, to the minimal interference with the balance during unlocking and impulse. A further key advantage of this escapement was that there was no need for oil on the escapement's working surfaces and hence no deterioration in the friction between the working surfaces as the oil aged. A drawback was that the detent escapement as it was used in pocket chronometers was prone to stopping as a result of motion. Most escapements are capable of being stopped by a sudden movement but the detent escapement gives an impulse to the balance only when it is moving in one direction. The escapement is therefore not self-starting. The lever escapement, as used in most modern mechanical watches, avoided this problem. In common with most other escapements it gave an impulse to the balance in both directions of the balance swing. This creates another problem in doing so because the introduction of a lever between the balance and the final (escape) wheel of the escapement requires lubrication on the acting surfaces.
Seth Glanville Atwood was an American industrialist, community leader, and horological collector. He was the chairman and president of Atwood Vacuum Machine Company, one of the world's largest manufacturers of automobile body hardware, and a long-time leader of the Atwood family's business which involved in manufacturing, banking and hotel industries, with over 2,500 employees. In addition, Atwood was a director of the Illinois Manufacturers' Association, and had served in the Illinois Chamber of Commerce and the Graduate School of Business at the University of Chicago.