Loudspeaker
Patent 4100992 Issued on July 18, 1978. Estimated Expiration Date: 
March 28, 1997. 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.
March 28, 1997. 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 RE24141 1459803 2124834 2302178 2408038 2502853 2716462 InventorsApplicationNo. 05/782718 filed on 03/28/1977US Classes:181/166, With damping means181/167Critically defined material or coatingExaminersPrimary: Hix, L. T.Assistant: Fuller, Benjamin R. Attorney, Agent or FirmInternational ClassesH04R 9/00 (20060101)H04R 7/00 (20060101) H04R 7/14 (20060101) H04R 9/04 (20060101) Foreign Application Priority Data1974-08-12 FRAbstractA loudspeaker including a porous diaphragm having an outside edge, an electromagnetic drive means mounted on a central area of the diaphragm for displacing the diaphragm and a hard ring forming a junction between the diaphragm and the drive means with the diaphragm being totally permeated with a stiffening material in the area between the ring and the outer edge without increasing the thickness of the diaphragm thereby improving the acoustic characteristics of the loudspeaker as compared with an equivalent unstiffened diaphragm. | |
