Franz Reuleaux (; ; 30 September 1829 – 20 August 1905) was a German

mechanical engineer Mechanical may refer to: Machine * Machine (mechanical), a system of mechanisms that shape the actuator input to achieve a specific application of output forces and movement * Mechanical calculator, a device used to perform the basic operations o ...

and a lecturer at ''Technische Hochschule Berlin'' (today Technische Universität Berlin), later appointed as the president of the academy. He was often called the father of

kinematics In physics, kinematics studies the geometrical aspects of motion of physical objects independent of forces that set them in motion. Constrained motion such as linked machine parts are also described as kinematics. Kinematics is concerned with s ...

. He was a leader in his profession, contributing to many important domains of science and knowledge. Today, he may be best remembered for the Reuleaux triangle, a curve of constant width that he helped develop as a useful mechanical form.

Biography

Early life

Reuleaux was born in Eschweiler in

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

(at the time part of

Prussia Prussia (; ; Old Prussian: ''Prūsija'') was a Germans, German state centred on the North European Plain that originated from the 1525 secularization of the Prussia (region), Prussian part of the State of the Teutonic Order. For centuries, ...

). His father and grandfather were both mechanical engineers. His technical training was at the Karlsruhe Polytechnic School. He then studied at universities in Berlin and Bonn.

Middle years

After a time spent in the family business he became a professor at the Swiss Federal Institute in

Zürich Zurich (; ) is the list of cities in Switzerland, largest city in Switzerland and the capital of the canton of Zurich. It is in north-central Switzerland, at the northwestern tip of Lake Zurich. , the municipality had 448,664 inhabitants. The ...

. Eventually, in 1879 he became Rector at the Königs Technischen Hochschule Berlin – Charlottenburg. This was a major technical institute, with about 300 professors. He became widely known as an engineer-scientist — a professor and industrial consultant, education reformer and leader of the technical elite of Germany. Reuleaux was the appointed chairman of the German panel of judges for the Sixth World Industrial Fair opened in

Philadelphia Philadelphia ( ), colloquially referred to as Philly, is the List of municipalities in Pennsylvania, most populous city in the U.S. state of Pennsylvania and the List of United States cities by population, sixth-most populous city in the Unit ...

on 10 May 1876. He admitted that German-made goods were far inferior to those of other countries and that German industry's guiding principle was “billig und schlecht” ( English: cheap and shoddy). This shook business and evoked wide comment in the press. Reuleaux was a consultant to the development of the Otto-Langen internal combustion engine, winner of the 1867 World's Fair in Paris, France, based on efficiency. Reuleaux served on several international juries and commissions and considerably involved in formation of a

patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an sufficiency of disclosure, enabling discl ...

system, as he was active in German politics. In 1877, he was elected as a member of the

American Philosophical Society The American Philosophical Society (APS) is an American scholarly organization and learned society founded in 1743 in Philadelphia that promotes knowledge in the humanities and natural sciences through research, professional meetings, publicat ...

. He was a member of the Royal Swedish Academy of Sciences from 1882.

Kinematics

Reuleaux believed that machines could be abstracted into chains of elementary links called kinematic pairs. Constraints on the machine are described by constraints on each kinematic pair, and the sequence of movements of pairs produces a kinematic chain. He developed a compact symbolic notation to describe the topology of a very wide variety of mechanisms, and showed how it could be used to classify them and even lead to the invention of new useful mechanisms. At the expense of the German government, he directed the design and manufacture of over 300 beautiful models of simple mechanisms, such as the four-bar linkage and the crank. These were sold to universities for pedagogical purposes. Today, the most complete set are at

Cornell University Cornell University is a Private university, private Ivy League research university based in Ithaca, New York, United States. The university was co-founded by American philanthropist Ezra Cornell and historian and educator Andrew Dickson W ...

College of Engineering.The kinematic models for design digital library
/ref> Using his notation and methods for systematically varying the elements (e.g. inversions, changing relative sizes of the links, etc.) he showed how the four-bar linkage could be mutated into 54 mechanisms, which fall within 12 classes.

Bibliography

*''Kinematics of Machinery'' (1875)
ebook
*''The Constructor'' (1861) *''Kurzgefasste Geschichte der Dampfmaschine'' (1891) *''Thomassche Rechenmaschine'' (2d ed. 1892)

Notes

References

*Bragastini, Roberto ''Contributo per una interpretazione filosofica dell'opera di Franz Reuleaux'', Università degli Studi di Milano (Milan, 2003). *Moon, Francis "Franz Reuleaux: Contributions to 19th Century Kinematics and Theory of Machines". * *

External links

Kinematic Models for Design Digital Library (KMODDL)
br /> Movies and photos of hundreds of working mechanical-systems models at Cornell University. Also includes a
e-book library
of classic texts on mechanical design and engineering.
Reproductions of Franz Reuleaux's Kinematic Models
br /> Modern reproductions of the kinematic models as originally produced. {{DEFAULTSORT:Reuleaux, Franz 1829 births 1905 deaths People from Eschweiler German mechanical engineers Engineers from the Kingdom of Prussia Members of the Royal Swedish Academy of Sciences Academic staff of ETH Zurich Academic staff of Technische Universität Berlin Engineers from North Rhine-Westphalia International members of the American Philosophical Society