Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Browse by Category: Main > Communications
Class Information
Number: 181/138
Name: Acoustics > Mechanical telephone
Description: Subject matter wherein sound is transmitted by the vibrations of molecules set up by mechanical means in a wire, string or flexible member strung taut.










Patents under this class:

Patent Number Title Of Patent Date Issued
5579398 Electro-acoustic transducer Nov. 26, 1996
5127870 Echo-type toy megaphone Jul. 7, 1992
4195707 Communicating device Apr. 1, 1980
4194095 Fluid flow control speaker system Mar. 18, 1980
4187635 Method and apparatus for sound production Feb. 12, 1980
4002897 Opto-acoustic telephone receiver Jan. 11, 1977











 
 
  Recently Added Patents
Automated security analysis for federated relationship
Organic electroluminescence element
Polyurethane resin, toner for developing electrostatic charge image, electrostatic charge image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method
Method of forming a semiconductor package
Digital broadcast receiver and method for processing caption thereof
Methods and systems for assessing sales activity of a merchant
System and method for wireless messaging in a wireless communication system
  Randomly Featured Patents
Method for straightening a metal strip and straightening machine
Ultrasonic flow velocity measuring method
Control device for an appliance
Emergency call handling in a wireless communication system
Print head driving system
Compound semiconductor having a doped layer between the gate and an ohmic contact of an active region
Turbine bearing lubrication system
Aminopyrazole derivatives
Modular wireless device test set
Adherent, flame-resistant acrylic decorative coating composition for wall board and the like