Bilgram, Hugo

SUBJECT AREA: Mechanical, pneumatic and hydraulic engineering

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b. 13 January 1847 Memmingen, Bavaria, Germany

d. 27 August 1932 Moylan, Pennsylvania, USA

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German (naturalized American) mechanical engineer, inventor of bevel-gear generator and economist.

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Hugo Bilgram studied mechanical engineering at the Augsburg Maschinenbau Schule and graduated in 1865. He worked as a machinist and draughtsman for several firms in Germany before going to the United States in 1869.

In America he first worked for L.B.Flanders Company and Southwark Foundry \& Machine Company in Philadelphia, designing instruments and machines. In the 1870s he also assisted in an evening class in drawing at The Franklin Institute. He devised the Bilgram Valve Diagram for analysing the action of steam engine slide valves and he developed a method of drawing accurate outlines of gear teeth. This led him to design a machine for cutting the teeth of gear wheels, particularly bevel wheels, which he patented in 1884. He was in charge of the American branch of Brehmer Brothers Company from 1879 and in 1884 became the sole owner of the company, which was later incorporated as the Bilgram Machine Works. He was responsible for several other inventions and developments in gear manufacture.

Bilgram was a member of the Franklin Institute, the American Academy of Political and Social Science, the Philadelphia Technische Verein and the Philadelphia Engineer's Club, and was elected a member of the American Society of Mechanical Engineers in 1885. He was also an amateur botanist, keenly interested in microscopic work.

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Principal Honours and Distinctions

Franklin Institute Elliott Cresson Gold Medal. City of Philadelphia John Scott Medal.

Bibliography

Hugo Bilgram was granted several patents and was the author of: 1877, Slide Valve Gears.

1889, Involuntary Idleness.

1914, The Cause of Business Depression.

1928, The Remedy for Overproduction and Unemployment.

Further Reading

Robert S.Woodbury, 1958, History of the Gear-cutting Machine, Cambridge, Mass, (describes Bilgram's bevel-gear generating machine).

RTS