| 摘要 |
PCT No. PCT/SE91/00352 Sec. 371 Date Oct. 27, 1992 Sec. 102(e) Date Oct. 27, 1992 PCT Filed May 16, 1991 PCT Pub. No. WO91/17841 PCT Pub. Date Nov. 28, 1991.The invention relates to a method and apparatus for the generation of low frequency sound by means of the excitation of a low frequency standing gas borne sound wave. A low frequency sound generator comprises a resonator part and a feeder part with a feeder unit. The method consists of a controlled generation of periodic changes of the gas volume of the resonator part in order to create a standing sound wave. The invention also includes a feeder unit for the working of the method. The feeder unit comprised of three rotating parts, namely one center rotor and two side rotors, the rotation of which are synchronized. The feeder unit is open on two sides, each side communicating with one tubular resonator. The rotors are provided with cut out portions and the center rotor is also provided with a protruding vane-shaped part. It is the rotation of the rotors in combination with their special shapes that generate periodic changes of the gas volume in the resonators without any internal compression in the feeder unit. |
