A plastic pipe part 1 comprising longitudinally extending channels 4 in its wall, spinwelded to a widened end portion 8, 8 min and spigot end portion 20, respectively which present a conically extending welding surface 9, 9a, having a top angle comprised between 90 and 160 DEG . For centering purposes the widened end portion 8, 8 min and spigot end portion 20 respectively may be provided with a c...

An optical focusing-error detection device comprises a beam splitter arranged in the path of a radiation beam originating from a plane on which is to be focused, and a radiation-sensitive detection system comprising a plurality of detectors separated by narrow strips, a first strip being associated with a first one and a second strip with the second one of two subbeams formed by the beam splitter....

An optical focusing-error detection device comprises a beam splitter arranged in the path of a radiation beam originating from a plane on which is to be focused, and a radiation-sensitive detection system comprising a plurality of detectors separated by narrow strips, a first strip being associated with a first one and a second strip with the second one of two subbeams formed by the beam splitter....

A phone booth housing includes a back piece (1), sidepieces (16), and a roof (4). These pieces are arranged to be included in a pre-assembly packaging that from an external view presents relatively little outer volume. In the packing, two or more pieces are folded upon one another. During assembly the back piece is erected first, after which the roof (4) is attached. The sidepieces fit into tracks...