Davidson, Shelby
1868-1931 · Contribution: 1908-1911
Rewind device for adding machines; automatic fee-calculation device for postal clerks
Portraits are AI-generated interpretations, not photographs.
Impact on the world
His rewind device for calculating machines reduced paper waste and processing time for U.S. government auditing operations by an estimated three-fourths, and his automatic fee device improved accuracy in postal fee assessment nationwide.
Life & background
A government auditor who moved from Kentucky to Washington, D.C. to work in the U.S. Post Office Department's auditing division, Davidson became fascinated with improving the adding machines used in government accounting. After two years studying machine manufacturing, he patented a rewind device in 1908 that he calculated could save the government three-fourths of the paper used on calculating machines, and in 1911 patented an automatic fee device to help postal clerks calculate correct postage fees.
Sources
- MIT Press Reader (300 Years of African-American Invention and Innovation); U.S. Patent 884,721; Notable Kentucky African Americans Database (Univ. of Kentucky)
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