Hanfried Kerle

Kinematics of the Human Forearms Pro- and Supination

In this paper a new kinematic model is introduced describing the motion of the human forearm during pronation and supination (Fig. 1,2). The necessity for a new description of the kinematic behavior of the forearm bones is given by the fact, that the usually taught kinematic model, introduced by R. FICK in 1904 is not sufficient to describe the effects of Open image in new window Figure 1. Pronation (Kapandji, 1992) Open image in new window Figure 2. Supination (Kapandji, 1992) angulations in the bones that often result from forearm-fractures. A more detailed description of the influence of angulated bones on the range of motion is important in the quest for the appropriate therapy in every particular case of a forearm-fracture. The here presented kinematic model can be used to predict the influence of angulations on the range of motion. As a result of that it can help the surgeon to decide weather or not an operation is necessary to obtain a free mobility of the forearm. If an operation, in which the bone is manually broken and repositioned, is found to be useful, the model can be used to predict its results. With this knowledge a strategy for an optimal operation can be found.

Presentation of the Lifework of Kurt Hain: Pioneer of Applied Kinematics in Germany

Dr.-Ing. E.h. Kurt Hain was born 1908 in Leipzig and died 1995 in Braunschweig. He was a pioneer of applied kinematics in Germany. He also visited American universities four times starting in 1957. He wrote 13 books and about 380 articles on nearly all partial fields of kinematics. This paper tries to give a complete survey of his lifework and describes a national research approach to preserve his heritage for future generations of mechanical engineers.Copyright

About Karl Hoecken and Some of His Works on Mechanisms

After the death of Wilhelm Hartmann in 1922, the direct successor of Franz Reuleaux on the Chair of Kinematics (Lehrstuhl fur Getriebelehre) at the Technische Hochschule (TH) Berlin-Charlottenburg, there was a row of intermediate professors until Hermann Alt from Dresden finally got the chair in 1939. Karl Hoecken belonged to this row of intermediate professors between 1930 and 1934. Looking through Hoecken´s estate we can find some new aspects of the famous kinematic model collection established by Reuleaux. This paper also takes up three publications of Hoecken on mechanisms, models and their kinematic equations, and thus gives a short historical overview over Hoecken´s contribution to the field of kinematics at that time. Incidentally, Hoecken himself added 26 own models to the then Reuleaux collection.

On the Power Transmission and Running Quality of Micro-Mechanisms

Generally micro-mechanisms are mechanisms of smaller dimensions compared with their correspondingly similar and bigger original ones that are really or only virtually existing on a special design stage. It is the goal of this paper to find out the conditions under which downward scaled micro-mechanisms can match with their original ones on a mechanically correct level concerning the transmission of mechanical power and running quality.

The History of Mechanism and Machine Science (HMMS) and IFToMM's Permanent Commission for HMMS

In this paper we put machines and mechanisms, Mechanism and Machine Science (MMS) and the foundation of the International Federation for the Theory of Machines and Mechanisms (IFToMM) in the wide perspective of the economic history of the world and we devote some attention to the activities of IFToMM’s Permanent Commission for the History of MMS.

From Archimedean Spirals to Screw Mechanisms – A Short Historical Overview

Mathematics forms the common roof for Archimedean spirals on the one side and screw mechanisms on the other side. Moreover, Archimedes was a genius of mechanics and mechanisms and was famous for solving mathematical and mechanical problems. There is also a historical justification for the title of the present paper, because the technical notion “Archimedean water-screw” is well-known to those mechanical engineers who are fond of looking back to the ideas and inventions of some famous protagonists and forerunners in the past and still today want to learn from their successes and failures.

Animal Kinematics — A Review of a Study of Franz Reuleaux about Restrained Animal Motions

Franz REULEAUX was a famous German engineer and professor who was born 1829 in Eschweiler in the vicinity of Aachen. He taught kinematics in Zurich (Switzerland) and Berlin where he died in 1905. At the end of the second volume of his main work titled “Theoretical Kinematics” there is an appendix about “Kinematics in Animal Kingdom” where REULEAUX compares moving parts of animals — preferably fish, crustaceans and insects — with mechanisms formed by links and joints. The (not directly expressed) goal of REULEAUX was to prove that his way of understanding and teaching kinematics went parallel to nature’s evolution and therefore had the best chance to survive in a world of competitive engineering scientists.

Dynamische Maschinenanalyse mit Hilfe programmierbarer Tischrechner

ZusammenfassungEine nichtlineare Differentialgleichung 2. Ordnung mit periodischen Koeffizienten beschreibt das Verhalten einer starren Maschine mit dem Antriebsdrehwinkel ϕ als Freiheitsgrad unter dem Einfluß eines autonomen Kraftfeldes. Die Differentialgleichung läßt sich auf ein Anfangswertproblem zurückführen und nach dem “Polygonzug-Verfahren” mit Hilfe eines programmierbaren. Tischrechners lösen, wobei anhand der Periodizitätsbedingungen die Güte der numerischen Rechnung kontrolliert werden kann.

The Automaton Nysa: Mechanism Design in Alexandria in the 3d Century BC

The paper is about the automaton Nysa, which operated in the Grand Procession of Ptolemy Philadelphus in the first half of the 3rd century BC. What was its design? We discuss several possible answers to this question. We give special attention to the mechanism that made Nysa stand up and sit down again. We argue that a cam was used and that the motion was slowed down either by means of a sprocket chain or—as Lewis suggested in 1997—by means of two gear wheels. We feel that the problem dealt with in this paper could fruitfully be used in engineering education.

Grundlagen der Synthese ebener viergliedriger Gelenkgetriebe

Zur Getriebesynthese gehort im Wesentlichen 1. die Festlegung der Getriebestruktur (Typensynthese bzw. Struktursynthese) 2. die Bestimmung kinematischer Abmessungen (Massynthese ) und die 3. konstruktive Gestaltung der Getriebeglieder und Gelenke unter Berucksichtigung der Belastung und des Materials.