Abstract: A plug-and-socket device includes a plug pin, and a contact sleeve having a cavity extending in a direction of an insertion axis for receiving the plug pin. The contact sleeve includes at least two contact fingers arranged in parallel relationship to one another around the cavity and configured to move elastically apart while expanding the cavity when the plug pin is inserted. At least one of the at least two contact fingers is formed on an inner side in facing relation to the cavity with at least one depression which lies in a contact surface on the inner side and defines with the contact surface an edge angle of less than approx. 100°. The contact surface represents on the inner side of the contact finger a surface which comes into contact with the plug pin, when the plug pin is inserted.

Abstract: An apparatus includes running surfaces made from metallic I-beams one of the flanges of which is adapted to support tires, whereas the web is adapted to receive flat strips which are substantially perpendicular to the web. At least one of the flanges is adapted to receive stiffening flat strips which are substantially parallel to the web. Troughs made from a metallic U-section channel are adapted to be fixed at least partly to one of the flat strips and flanges and open toward the flange adapted to support the tires. Such flanges, web, flat strips and channel are united to constitute a formwork into which is poured concrete whose level is flush with the level of the flanges.

Abstract: A switch for a floor transportation system is described, whereby a guide rail is provided below the floor level. A guide pin extends into this guide rail. In front of this guide pin, a guide shoe of ferromagnetic material is pivotally provided. In the area of the switch, the side walls of the guide rail are provided with electromagnets which pull the guide shoe toward the one or the other wall area so that the guide shoe and the guide pin can be directed into one or the other branch rail of a guide rail fork.