Telegraph Key Patent Model

Description (Brief)
Telegraph keys are electrical on-off switches used to send messages in Morse code. The message travels as a series of electrical pulses through a wire. The sequence and duration of pulses represent letters and numbers. This patent model shows Lucien Crandall's design for an automatic key. His idea involved a key for each letter, number and character, set on a frame like a typewriter. Each key included a ratcheted wheel with conducting and insulated segments around the edge. When the operator pressed a key, the wheel rotated and generated morse code pulses at a regular speed. His goal was to permit operators to send messages, "with greater rapidity, uniformity, and certainty than with the common telegraphic key."
Location
Currently not on view
date made
1875
maker
Crandall, Lucien S.
Physical Description
wood (overall material)
metal (overall material)
gutta percha (overall material)
Measurements
overall: 6 in x 2 1/2 in x 1 in; 15.24 cm x 6.35 cm x 2.54 cm
ID Number
EM.308883
catalog number
308883
accession number
89797
patent number
168144
See more items in
Work and Industry: Electricity
Communications
Telegraph Keys
Data Source
National Museum of American History, Kenneth E. Behring Center

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