Abstract
Two overconstrained mechanisms are presented that both are related to regular polyhedra in the Euclidean 3-space. The first example, the HEUREKA-polyhedron, is a modification of BUCKMINSTER-FULLERS Jitterbug [1]. The spherical joints at the vertices of 8 regular triangles are replaced by particular cardan joints. A 15m high model of this polyhedron was exhibited at the national research exposition of Switzerland 1991 in Zürich. Further the GRÜNBAUM-framework is discussed. Here the 10 regular tetrahedra inscribed to a regular pentagon-dodecahedron are linked together at the common vertices. This framework allows at least two types of constrained motions. The first was found by R. Connelly [2]. These motions preserve the fivefold symmetry with respect to any face axis. Motions of the two second type preserve the symmetry with respect to any vertex axis.
Similar content being viewed by others
Literature
R. BUCKMINSTER FULLER: Synergetics: Explorations in the geometry of thinking. Macmillan, New York 1975, p. 190–215.
R. CONNELLY: Using Kaleidoscopes to Build Mechanisms. Proc. Conf. Intuitive Geometry, Szeged 1991 (im Druck).
A. L. MACKAY: A dense non-crystallographic packing of equal spheres. Acta Crystallographica15 (1962), 916–918.
B. ROTH: Rigid and flexible frameworks. Am. Math. Mon.88 (1981), 6–21.
H. STACHEL: Ein bewegliches Tetraederpaar. Elem. Math.43 (1988), 65–75.
H. STACHEL: The HEUREKA-Polyhedron. Proc. Conf. Intuitive Geometry, Szeged 1991 (im Druck).
W. WUNDERLICH: Ein merkwürdiges Zwölfstabgetriebe. Österr. Ingen. Archiv.8 (1954), 224–228.
W. Wunderlich: Geometrie und Schönheit. Inaugurationsrede, Technische Hochschule Wien, 1964.
W. WUNDERLICH: Kipp-Ikosaeder I, II. Elem. Math.36 (1981), 153–158 und37 (1982), 84–89.
W. WUNDERLICH: Shaky polyhedra of higher connection. Publ. Math.37 (1990), 355–361.
Author information
Authors and Affiliations
Additional information
Vortrag, gehalten aus Anlaß der Ehrenpromotion von Herrn Prof. Dr. W. Wunderlich an der TU München am 6. November 1991.
Rights and permissions
About this article
Cite this article
Stachel, H. Zwei bemerkenswerte bewegliche Strukturen. J Geom 43, 14–21 (1992). https://doi.org/10.1007/BF01245938
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01245938