Motor vehicle alarm system with acoustic signal emission via at least one radio loudspeaker installed into the motor vehicle

US4612530A · kind A · utility

Assignee

• Daimler-Benz AG · DE

Inventors

• Hermann W. Kurth · Sindelfingen, DE
• Peter Robitschko · Sindelfingen, DE

Key dates

• Filing date: Apr 12, 1985
• Grant date: Sep 16, 1986
• Expiry date: Apr 12, 2005

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B60Q5/00
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

An alarm system having improved acoustic signal transmitting capability is provided for motor vehicles. The radio speaker system of the vehicle is employed for both passenger listening and for warning signal transmission in the event of unauthorized intrusion or attempted theft. The speakers occupy their usual installation positions in a vehicle, such as horizontally mounted in the dashboard, when used for the purpose of listening to a radio or tape. When the vehicle is unoccupied, and theft or tampering are attempted, an alarm system is activated which causes a control element to swivel the speaker into a position parallel to an external surface of the vehicle. Due to this repositioning of the speaker, reflection of an alarm signal back into the interior of the vehicle is minimized, and transmission of the alarm signal to the outside of the vehicle is optimized.