Electro-acoustic transducer diaphragms
Patent 4020299 Issued on April 26, 1977. Estimated Expiration Date: 
April 26, 1994. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
April 26, 1994. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 982027 1097499 1560552 1673661 3093207 InventorsAssigneeApplicationNo. 05/578916 filed on 05/19/1975US Classes:381/432, Conical181/166, With damping means381/354, Absorbing or attenuating element381/429Apertures in surfaceExaminersPrimary: Brown, Thomas W.Attorney, Agent or FirmForeign Application Priority Data1973-06-16 UKAbstractAn electro-acoustic transducer having a sound-generating diaphragm and means for driving the diaphragm in which the diaphragm is provided with perforations filled with damping material to oppose the formation of standing waves in the diaphragm. The perforations are arranged in between three and eight generally radially extending curved bands, each band being formed of a plurality of parallel rows of perforations extending along the length of the band. | |
