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The axial flow valve, or Thayer valve, is a brass instrument valve design patented in 1978 by Orla Ed Thayer. [1] Designed with assistance from Zigmant Kanstul, it was originally intended to replace the traditional rotary valve on the French horn, but instead revolutionized the design of trombone valve attachments. [2] Combined with open-wrap tubing, it eliminates the impedance caused by tight tubing bends, improving the airflow through the instrument and the open "feel" perceived by the player.
When engaged, a rotary valve deflects the air flow through extra valve tubing, using tight, small radius bends of at least 90° angles, leading to a stuffy response and audible tone colour changes, compared to the "open" instrument. These drawbacks are especially noticeable on the trombone, since its characteristic timbre results directly from its cylindrical bore and almost completely straight construction. Valve tubing aside, there are only two bends, one each in the slide and bell section. In contrast, the distinctly softer sound of other brass instrument families like the horns, saxhorns, and tubas is at least partially a result of their conical bore and their intricate construction with many bows and bends.
The change in timbre and response in the valve section was also made more pronounced by the wrap of the valve tubing, traditionally in several tight loops to fit the length of tubing within the bell section, that was the norm until the 1980s.
The Thayer Valve uses a conical rotor (although the 1978 patent and early prototypes were cylindrical), with its spindle rotation axis parallel to the incoming and outgoing tubing. The airflow undergoes a maximum of 28° of deflection through the valve, which makes an F attachment's open-wrap tubing even more efficient. As a result, the response, tone colour and other playing characteristics are nearly unchanged from those of the open instrument, even on bass trombones with two independent valves fitted.
There were several problems with early Thayer valve designs, noted by players and instrument repairers.
Valves sometimes suffered from galvanic corrosion due to the use of unsuitable metals in the manufacture of different parts of the valve. Early valves used cast brass for the rotors, which made them heavy and slow to actuate; an initial solution to this problem was to use aluminium and other metal alloys for the rotor to try to reduce its mass.
The conical rotor's spindle was only anchored at the wide end of the cone, the other end free to rotate inside the casing. This "floating" tip of the conical rotor would undergo precession or "wobble", which caused wear where it meets the inside of the valve casing, becoming loose as a result, and leading to further problems such as air leaks and lubricant loss. Thus, the Thayer valve can have higher cleaning, maintenance and lubrication requirements than other valve designs. They can also be more difficult to disassemble and clean than a standard rotary valve, especially on double-valve bass trombones.
Some players, especially bass trombonists, claim that more resistance enhances the response of low notes on the valve side (below E♭). This group finds playing open flowing designs like the axial flow valve to be more of a strain. [2]
Thayer filed several further patents in the 1980s which attempted to solve some of the initial design problems, as well as other innovations to reduce costs of manufacture and improve the speed of action. These involved using spring tensioners to hold the rotor against the casing to prevent air leaks, and using materials such as plastic or Teflon for the rotor, to reduce its mass and prevent corrosion issues. [3]
Cristian Bosc, Italian brass instrument maker, has improved the axial flow valve design by fabricating both the rotor and the valve casing from single pieces of solid brass with no soldered parts. This was to address leakage and corrosion problems. [4]
A 2011 patent granted to Michael Olsen of Instrument Innovations also greatly improved the valve by (among other things) mounting bearings at both ends of the rotor spindle. This increased the speed and reliability of the action, and eliminated the "floating rotor" design problem and its associated wear and precession issues. [5] Vincent Bach use this design for their "Infinity Valve" on their "AF" trombones, which replaced their "T" trombones that used the older Thayer design. [6]
The invention of the Thayer Valve kicked off an "arms race" among trombone designers and manufacturers that continues today. Newer valve designs include the relatively successful Swiss Hagmann valve found on trombones from many European manufacturers, the Christian Lindberg valve from Conn, the S.E. Shires Tru-Bore valve, the Balanced Valve System or "K" valve from Bach in the 1990s, as well as less successful designs like the Miller valve and the Yamaha "V" valve. [2]
This activity has also spurred many patents and refinements in traditional rotary valve designs for other instruments as well as trombones, such as the Willson Rotax valves found on many French horns and tubas, the Lätzsch "Full Flow" valve, the Greenhoe valve, the Kanstul "Controlled Resistance" valve, and the Edwards AR-1 valve.
A brass instrument is a musical instrument that produces sound by sympathetic vibration of air in a tubular resonator in sympathy with the vibration of the player's lips. Brass instruments are also called labrosones or labrophones, from Latin and Greek elements meaning 'lip' and 'sound'.
The euphonium is a medium-sized, 3 or 4-valve, often compensating, conical-bore, tenor-voiced brass instrument that derives its name from the Ancient Greek word εὔφωνος euphōnos, meaning "well-sounding" or "sweet-voiced". The euphonium is a valved instrument. Nearly all current models have piston valves, though some models with rotary valves do exist.
The French horn is a brass instrument made of tubing wrapped into a coil with a flared bell. The double horn in F/B♭ is the horn most often used by players in professional orchestras and bands, although the descant and triple horn have become increasingly popular. A musician who plays a horn is known as a horn player or hornist.
The pitch of a brass instrument corresponds to the lowest playable resonance frequency of the open instrument. The combined resonances resemble a harmonic series. The fundamental frequency of the harmonic series can be varied by adjusting the length of the tubing using the instrument's valve, slide, key or crook system, while the player's embouchure, lip tension and air flow serve to select a specific harmonic from the available series for playing. The fundamental is essentially missing from the resonances and is impractical to play on most brass instruments, but the overtones account for most pitches.
The trombone is a musical instrument in the brass family. As with all brass instruments, sound is produced when the player's vibrating lips cause the air column inside the instrument to vibrate. Nearly all trombones use a telescoping slide mechanism to alter the pitch instead of the valves used by other brass instruments. The valve trombone is an exception, using three valves similar to those on a trumpet, and the superbone has valves and a slide.
The tuba is the largest and lowest-pitched musical instrument in the brass family. As with all brass instruments, the sound is produced by lip vibration – a buzz – into a mouthpiece. It first appeared in the mid-19th century, making it one of the newer instruments in the modern orchestra and concert band, and largely replaced the ophicleide. Tuba is Latin for "trumpet".
The tenor horn is a brass instrument in the saxhorn family and is usually pitched in E♭. It has a bore that is mostly conical, like the flugelhorn and euphonium, and normally uses a deep, cornet-like mouthpiece.
The mellophone is a brass instrument used in marching bands and drum and bugle corps in place of French horns. It is a middle-voiced instrument, typically pitched in the key of F, though models in E♭, D, C, and G have also historically existed. It has a conical bore, like that of the euphonium and flugelhorn. It can also be used to play French horn parts in concert bands and orchestras.
The valve trombone is a brass instrument in the trombone family that has a set of valves to vary the pitch instead of a slide. Although it has been built in sizes from alto to contrabass, it is the tenor valve trombone pitched in B♭ an octave lower than the trumpet which has seen the most widespread use. The most common models have three piston valves. They are found in jazz and popular music, as well as marching bands in Europe, where they are often built with rotary valves and were widely used in orchestras in the 19th century.
A rotary valve is a type of valve in which the rotation of a passage or passages in a transverse plug regulates the flow of liquid or gas through the attached pipes. The common stopcock is the simplest form of rotary valve. Rotary valves have been applied in numerous applications, including:
The cimbasso is a low brass instrument that covers the same range as a tuba or contrabass trombone. First appearing in Italy in the early 19th century as an upright serpent, the term cimbasso came to denote several instruments that could play the lowest brass part in 19th century Italian opera orchestras. The modern cimbasso design, first appearing as the trombone basso Verdi in the 1880s, has four to six rotary valves, a forward-facing bell, and a predominantly cylindrical bore. These features lend its sound to the bass of the trombone family rather than the tuba, and its valves allow for more agility than a contrabass trombone. Like the modern contrabass trombone, it is most often pitched in F, although models are occasionally made in E♭ and low C or B♭.
The superbone is a hybrid tenor trombone in B♭ that has both a slide like a regular trombone and a set of valves like a valve trombone.
The bass trombone is the bass instrument in the trombone family of brass instruments. Modern instruments are pitched in the same B♭ as the tenor trombone but with a larger bore, bell and mouthpiece to facilitate low register playing, and usually two valves to fill in the missing range immediately above the pedal tones.
Marching brass instruments are brass instruments specially designed to be played while moving. Most instruments do not have a marching version - only the following have marching versions:
Valve oil is a lubricant for valves of brass instruments. It is typically mostly mineral oil with a small amount of other ingredients, although synthetic oils are increasingly available.
The Hagmann Free-Flow Valve is a trademarked brass instrument valve design developed by Swiss musician and instrument technician René Hagmann, first introduced for trombone F attachments in 1990. His intention was to address some of the geometrical limitations of the regular rotary valve, as well as the reliability and maintenance issues of the popular Thayer axial flow valve that arise from its relatively complex design.
The Kuhlohorn is a small flugelhorn in B♭. This is a specially designed brass wind-instrument played using a deep bowled mouth piece. Chief characteristics are its oval design and integrated, usually conical tubing. Kuhlohorns commonly are featuring a conical tuning slide, at the second curved pipe section after the rotary valves.
Ernst Albert Couturier was best known as a cornet player who toured as a "virtuoso" performer on the concert programs of bands of the day. He promoted the Holton Band Instrument Company for a decade in that capacity before applying his own unique inventions to the production of his own line of brass band instruments between 1918 and 1923.
Brass instrument valves are valves used to change the length of tubing of a brass instrument allowing the player to reach the notes of various harmonic series. Each valve pressed diverts the air stream through additional tubing, individually or in conjunction with other valves. This lengthens the vibrating air column thus lowering the fundamental tone and associated harmonic series produced by the instrument. Valves in brass instruments require regular maintenance and lubrication to ensure fast and reliable movement.