Car Signals.—Numerous devices are now on the market designed to be located both in front and in rear of the vehicle, which are intended to indicate direction, as well as to impart other information.
These signals are under control of the driver, and have signs on them which indicate “stop,” “right,” “left,” or other words which conspicuously display the intention of the driver.
All machines have signaling horns of some character, operated, usually, by some mechanical arrangement connected with the gearing or by compressed air, and others are connected up with the engine exhaust. Chime whistles are so operated.
Speed Signals.—Other inventions are designed to indicate, by automatic mechanism, the speed of the car, in which color displays the relative speed. Thus, a car going at the normal speed, say 10 miles per hour, would show a white light; from 10 to 15 miles, blue; from 15 to 20 miles, green; and above that speed, red.
The foregoing colors and speeds are arbitrarily selected, merely to show the ideas involved. The device in question has nothing whatever to do with the regular speed registering mechanism of the car, but is designed to show pedestrians and police officials the actual running speed at a glance.
Mufflers.—There is really no excuse for noisy automobiles. Mufflers are now made which absolutely eliminate all noise from the exhaust. The great difficulty in the past has been to make them sufficiently large for the engine. If too small they do not take care of the exhaust properly, and they also serve to check the flow of the exhaust gases from the engine, and thus greatly decrease the power of the engine.
Exhaust.—All racing engines are made without exhausts, so there will be nothing to retard the flow of the exhaust.
The function of the muffler is to receive the exhaust gas and permit it to expand as nearly as possible down to atmospheric pressure before delivering it to the air. Fig. 96 shows the simplest form in which it can be made.
Construction of Muffler.—The inner pipe A, from the engine exhaust, passes axially through a cylinder B, the pipe, however, being closed at its inner end where it is attached to the head C. Numerous small holes D are formed through this pipe for the escape of the burnt gases.
Within the cylinder B is a smaller cylinder E, surrounding the inner tube. This has one end attached to the head C, and its other end is open so as to provide a passage way F from the interior of the cylinder. The discharge ports are at G, through the head C.