A muffler (or silencer in British English) is a device for reducing the amount of noise emitted by the exhaust of an internal combustion engine. A US Patent for an Exhaust muffler for engines was granted to Milton and Marshall Reeves in 1897.
The patent for an Exhaust muffler for engines was awarded to Milton O. Reeves and Marshall T. Reeves of Columbus, Indiana of the Reeves Pulley Company on 11 May 1897. US Patent Office application No 582485 states that they have invented certain new and useful Improvements in Exhaust-Mufflers for engines ....
Mufflers are typically installed along the exhaust pipe as part of the exhaust system of an internal combustion engine. The muffler reduces exhaust noise by absorption—the exhaust is routed through a series of passages and chambers lined with roving fiberglass wool—and/or resonating chambers tuned to cause destructive interference wherein opposite sound waves cancel each other out, and Catalytic converters also have a muffling effect.
Changing the muffler / mini-muffler / catalytic converter combination can change the sound of a car's exhaust system considerably. Removing a vehicle's muffler or installing a less effective muffler than the original can cause the vehicle to violate noise regulations. Nevertheless some vehicle owners remove their car muffler in the belief it will improve performance, or just to make them louder.
Types and positions of mufflers
- With cars, lengthwise underneath, blowing backwards at the rear
- To the sides before the rear wheels.
- With large diesel-powered trucks:-
- Mounted vertically behind the cab
- Crosswise under the front of the cab, blowing sideways.
- With motorcycles:
- Usually, beside the engine and rear wheel blowing backwards.
- In more modern motorcycles, under the seat blowing backwards from under the back of the seat. (Under-slung)
- Under-engine exhausts first reached popularity with Buell motorcycles, though by 2008 most manufacturers began using the under-engine design as well.
Motorcycle enthusiasts sometimes use the term "raygun," "drag pipes", "pea-shooter" or "hotdog-style" for the old shape of motorcycle exhaust silencer/muffler with a long straight cylindrical barrel that merged roundedly at each end into the pipe, as in this image and this image.
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