In this paper the author finds and describes all similarity space motions, which have only plane trajectories of points. All such motions are explicitly expressed. They are of 5 types, all of them cylindrical. Trajectories are conic sections (3 types) or arbitrary plane curves (2 types).
There exist many examples of closed kinematical chains which have a freedom of motion, but there are very few systematical results in this direction. This paper is devoted to the systematical treatment of 4-parametric closed kinematical chains and we show that the so called Bennet’s mechanism is essentially the only 4-parametric closed kinematical chain which has the freedom of motion. According to [3] this question is connected with the problem of existence of asymptotic geodesic lines on robot-manipulators...
In der Ebene kann ein äquiformer Zwanglauf so bestimmt werden, daß jede Gerade einer beweglichen Ebene in einer festen Ebene eine zykloidale Kurve mit demselben Modul umhüllt. Das Problem wird ebenfalls im Raum gelöst und verallgemeinert.