Abstract: A sliding closure for a roadway expansion joint crossing has on the first part of the roadway (1) a sliding face (5) with a curved segment (7) and an adjoining level segment (8) running parallel to the driving surface (4). Resting flatly on this sliding face is a sliding plate (10) of elastomeric material and of uniform thickness. The sliding plate (10) is bolted onto the second part of the roadway (2) and bridges with a level section (12) a gap (11) between the first and second parts of the roadway (1, 2). In the level section (12), the sliding plate (10) is reinforced by a flexurally rigid steel plate (14). In the section resting on the curved segment (7), the reinforcement of the sliding plate (10) consists of a thin, flexible plate (15). Fastened on the first part of the roadway (1) is a tongue plate (32), which overlaps the sliding plate.

Abstract: The welding apparatus serves for the purpose of butt-welding of plastic pipes of diameters larger than 500 mm. All the work is performed by means of the welding apparatus from inside the pipe. Thereby the working time is reduced, the welding quality ensured, and the installation becomes faster. Lifting cranes and heating tents become unnecessary. A novelty is also the possibility of welding pipes together at an angle position. As the welding apparatus is collapsible, it may also be advantageously used for repair work on old pipes in the ground (relining), with a minimum exposure of the pipes.