DE860903C - Sound receiver of an overtaking signal system, especially for motor vehicles - Google Patents

Description

The invention relates to a sound receiver of an overtaking signal system, especially for motor vehicles.

To the driver of a truck the intention to overtake a behind The usual car horns are often not enough to tell him that the vehicle is moving the end. There are therefore several suggestions for eliminating this drawback so-called overtaking signal systems have been made, in which often a special signal transmitter was provided.

The system according to the invention triggers by the signal of a normal Car horn without using a tube amplifier an acoustic or optical Signal in the driver's cab of the truck to be overtaken.

The invention consists in that in a sound receiver of an overtaking signal system, especially for motor vehicles, which is designed as a membrane that has a contact that switches the signal circuit in the vehicle to be overtaken, the contact responds to membrane acceleration.

The drawing shows, for example, a schematic diagram of a sound receiver the invention.

A diaphragm i, tuned to the main formant of the frequency band of the car horns (around 3000 IIz), if necessary with the aid of an air cushion, carries a contact spring 2 which, when the diaphragm is at rest, touches an isolated contact 3 and thereby keeps a closed circuit connected to it closed. If the membrane is passed through the funnel q. sonicated, the contact opens when the membrane acceleration is greater than the acceleration imparted to the contact by the spring, ie when where a is the membrane amplitude, co is the exciting angular frequency, p is the spring force and m is the effective spring mass. The contact break is used to trigger the signal. This arrangement has the advantage that the system is relatively insensitive to vibrations, since very large amplitudes are required at low frequencies due to the dependence of the acceleration on co2 and, on the other hand, by means of suitable suspension of the system, it is possible to keep higher vibration frequencies away from the system.

The sensitivity of the arrangement for the useful frequency can be determined by appropriate choice of p and m can be largely influenced. p may in the interest of a sufficient contact pressure do not become too small. One must therefore m in the frame Make the maximum permissible total mass of the membrane as large as possible.

As . Diaphragm-shaped sound receiver for overtaking signal systems for motor vehicles are known that carry a contact in an adjustable Distance from a fixed mating contact. With a sufficiently large membrane oscillation the vibrating contact touches the fixed mating contact and thereby releases the signal circuit the end. In contrast to the subject matter of the invention, the known arrangement speaks accordingly not on the membrane acceleration, but on the vibration amplitude of the membrane so that even deep background noises can trigger the signal.

Claims (1)

Claim: Sound receiver of an overtaking signal system, in particular for motor vehicles, which is designed as a membrane carrying a contact that switches the signal circuit in the vehicle to be overtaken, characterized in that the contact responds to the membrane acceleration. Cited publications German patent specification No. 572 236.