US 5,208,787 A · Rodent control by sound waves

Abstract

A sound wave generator is effective for producing ultrasonic sound wave vibrations as well as low frequency vibrations which are offensive to rodents. A wiring conductor which serves as a sonic radiator is attached to an end portion of a solenoid rod which is reciprocated by a coil which is energized by alternating current power. The solenoid rod is permitted to vibrate within a hollow spool, and the sonic radiator is mechanically coupled to the solenoid rod by a high compliance, conductive metal spring. Ultrasonic sound waves are produced by forming the solenoid rod of a ferromagnetic material which is characterized by magnetostriction in the presence of an alternating magnetic field. The amplitude of sound wave vibration is intensified by selecting the length and diameter of the solenoid rod so that its natural frequency of vibration is in harmony with either the pulse frequency of the electromagnetic driving force, or alternatively, the frequency of ultrasonic sounds produced by magnetostriction. The sound wave generator circuit includes a pseudo-random signal generator for randomly gating the conduction of electrical alternating current through the solenoid coils during a pulsing duty cycle.

Claims11

Dependent claims

Apparatus for repelling rodents from a building having an AC wiring power distribution system including a hot conductor, a neutral conductor and a ground conductor electrically connected to a common AC service receptacle of the type having jacks for receiving plug prongs, said apparatus comprising:

a housing;
at least one coil in said housing operable to generate sound waves offensive to rodents when alternately energized and deenergized by an alternating electromagnetic field at a predetermined frequency;
a plug adapted to be received by the receptacle, said plug having a first pair of prongs for establishing electrical connection with the hot and neutral power conductors and a ground prong for establishing electrical connection with the ground conductor when the plug prongs are inserted into the AC service receptacle jacks;
an electrical circuit connected between the hot and neutral prongs, said circuit including said coil therein and operable to effect energization of the coil when said plug is inserted into an active AC service receptacle and said circuit is completed;
frequency control means for alternately completing and interrupting said circuit at a predetermined frequency;
an elongated bar disposed within said coil, said elongated bar having first and second end portions;
and,
a first wiring conductor having a first end portion attached to the first end portion of said bar and having a second end portion attached to one of the prongs of said plug.

5 more elements

Dependencies are inferred from the claim text.

Rodent control by sound waves

Life of this patent

Rodent control by sound waves

Life of this patent

Abstract

Claims11