Product Code Database
A horn is a sound-making device installed on , , , and other types of vehicles. The sound it makes usually resembles a “honk” (older vehicles) or a “beep” (modern vehicles). The driver uses the horn to warn others of the vehicle's presence or approach, or to call others’ attention to a hazard. Motor vehicles, ships and trains are required by law in some countries to have horns. Public transport vehicles and even bicycles are also legally required to have an audible warning device in many areas.
A traditional style automobile horn includes an expansion chamber cast into its body, once spiral shaped, to better match the acoustical impedance of the diaphragm with open air, and thus more effectively transfer the sound energy. Sound levels of typical car horns are approximately 107–109 , and they typically draw 5–6 of current.
Horns can be used singly, but are often arranged in pairs to produce an interval consisting of two notes, sounded together; although this doubles the sound volume, the use of two differing frequencies is more psychoacoustics to the human ear than two horns of the same frequency, particularly in an environment with a high ambient noise level. Typical frequencies of a pair of horns of this design are 500 Hz and 405–420 Hz (approximately B4 and G4, minor third).
Most cars, , and have for some time used a cheaper and smaller alternative design, which, despite retaining the name "horn," abandons the actual horn ducting and instead relies on a larger flat diaphragm to reach the required sound level. Sound levels of such horns are approximately 109–112 decibels, and they typically draw 2.5–5 amperes of current. Again, these horns can be either single, or arranged in pairs; typical frequencies for a pair are 420–440 Hz and 340–370 Hz (approximately G4–A4 and F4–F4) for this design.
A horn grille is a part of some designs of car or other motor vehicle that has an electric horn, such as a motor scooter.
Larger, louder , as found on (lorries) and , are driven by , or supplied by reservoirs charged to operate their air brakes. The compressor forces air past a diaphragm in the horn's throat, causing it to vibrate. Usually two are used, with varied frequencies generally lower than those of automobile horns, in the 125–180 Hz (approximately C3–G3) range. Sound levels are approximately 117–118 decibels.
To distinguish their sound from truck and bus air horns, train horns in the U.S. consist of groups of two to five horns (called "chimes") which have different notes, sounded together to form a chord.
In Japan, most modern trains like 209 series or E233 series from the first half of the 1990s onwards use electric horns as primary in passenger use. Although electric horns were used by Seibu 2000 series, air horns were primarily used until the 1990s. Modern Japanese trains may still be equipped with both air horns and electric horns.
Most modern streetcars, trams and trolley cars including low-floor vehicles around the world also employ horns or whistles as a secondary auditory warning signal in addition to the gong/bell which either use the sound of air horns or electric automobile car horns.
Smaller craft typically use electric diaphragm horns.
Portable driven by canned compressed air are also used, as well as for officiating sports events and recreational activities.
The klaxon horn's characteristic sound is produced by a spring-steel diaphragm with a rivet in the center that is repeatedly struck by the teeth of a rotating cogwheel. The diaphragm is attached to a horn that acts as an acoustic transformer and controls the direction of the sound.
In the first klaxons, the wheel was driven either by hand or by an electric motor. American inventor Miller Reese Hutchison (later chief engineer of Thomas Edison) patented the mechanism in 1908. US Patent 923,048. Applied March 14, 1908, granted May 25, 1909.
US Patent 923,049. Applied May 16, 1907, granted May 25, 1909.
The Lovell-McConnell Manufacturing Company of Newark, New Jersey bought the rights to the device and it became standard equipment on General Motors cars. Franklyn Hallett Lovell Jr., the founder, coined the name klaxon from the Ancient Greek verb klazō, "I shriek".
US Patent 923,122. Applied May 16, 1907, granted May 25, 1909.
Klaxons were first fitted to automobiles and in 1908. They were originally powered by six-volt , and from 1911 by rechargeable batteries. Later hand-powered versions were used as military evacuation alarms and factory sirens. They were also used as submarine dive and surface alarms beginning in the Second World War.
The English company Klaxon Signals Ltd. has been based in Oldham, England for the last 80 years, with premises also in Birmingham. The French Klaxon company was acquired by the Italian Fiamm Group in the 1990s. In 2005 Klaxon Signals sold the rights for the hooter or klaxon range to Moflash Signalling Ltd., based in the original Klaxon Factory in Birmingham, England.
The Moflash Company discontinued the Klaxet hooter in 2013, but continued to produce the A1 hooter, the only original Klaxon left in production.
The hornophone consists of a set of bulb horns tuned to a chromatic scale and arranged as a musical keyboard on a frame like a xylophone. The klaxophone is a similar musical instrument using a set of klaxons.
|
|
