Patent · US Expired

Hybrid active silencer

US4665549A · kind A · utility

80Cited by
8References
23Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 18, 1985
Grant dateMay 12, 1987
Priority date
Expiry dateDec 18, 2005

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG10K2210/509
  • WIPO fieldOther consumer goods
  • WIPO sectorOther fields

Abstract

Acoustic attenuation apparatus (2) is provided for a duct (4) guiding an acoustic wave propagating (6) therethrough. A silencer (8) is provided for passively attenuating the acoustic wave in the duct, and a cancelling speaker (32) is provided within the silencer. The combination provides hybrid active/passive combined attenuation. Various rectangular and circular structures are disclosed, together with multi-path and multi-speaker arrangements.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.