Bird-scaring method and device

US4769794A · kind A · utility

Assignee

• Battelle Institute e.V. · DE

Inventors

• Karl Beuter · Frankfurt am Main, DE
• Rainer Weiss · Hattersheim, DE

Key dates

• Filing date: Oct 7, 1986
• Grant date: Sep 6, 1988
• Expiry date: Oct 7, 2006

Classification

• Technology area (CPC G): Physics
• CPC primary: G10K15/02
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

For scaring birds, at least two acoustic signals are generated whose frequencies are periodically modulated within a range between about 30 and 9000 Hz, the modulation period ranging between about 0.01 and about 5 seconds. The signals differ in the frequency modulation range, in the modulation period and/or in duration. The signals are emitted either in fixed or in arbitrary sequence.