They Invented What? (No. 66)

U.S. Pat. No. 4,195,707:  Communicating device.

 

What is claimed is:

1. A device for communicating comprising a flat base and a hollow frustum integral therewith and extending outwardly therefrom, retaining means at the smaller end of said frustum, a discrete diaphragm complementary in shape to said smaller end of said frustum and held thereagainst by said retaining means, and means for connecting a string between a pair of said diaphragms, whereby when a string between two diaphragms is under tension conversation into one device is transmitted via the string to the other device.