" My present invention relates to that class
of speaking telephones adapted for operation
either as transmitters or as receivers; and my
improvement more especially relates to the
shape of the permanent magnet, the method
of combining it with the electro-magnet,
case, diaphragm, and mouth-piece, and with
the conducting wires."
G.M. Phelps June 4, 1879.
This series of telephones by Phelps was his most
widely used and distributed phone in the U.S.
The above photo courtesy of the Smithsonian Institution
The Pony Crown Telephone, The Single Crown Telephone, and The Double Crown Telephone were all derived from this patent. Instead of using a small permanent magnet as found with other designs of the day, Phelps used a number of permanent magnet bars bent in a circular form, the result was a shape that resembled a crown.
Single Crown on the left, Double Crown on the right.
George M. Phelps