Abstract: Disclosed is a fluid friction clutch which comprises an input shaft, a primary disk connected to the shaft, and a secondary drive part, i.e., the clutch housing. The primary disk rotates in a work chamber arranged in the clutch housing and includes a reserve chamber in its interior. A fluid stream, which circulates between the work chamber on the secondary side and the reserve chamber on the primary side, is controlled via a valve attached to the primary disk. The valve is actuated via a tappet arranged coaxially in the input shaft. The orifice of the valve is arranged on the end face of the primary disk, and the associated valve closure element is located in the interior of the reserve chamber. An overflow orifice is present on the circumference of the primary disk in conjunction with a baffle, whereby pumping of the fluid from the work chamber into the reserve chamber is achieved. This fluid friction clutch is used, preferably, as the fan drive means for a radiator in motor vehicles.

Abstract: There is disclosed a highway lane divider and road marker, having a relatively low profile, characterized by the inventive feature of a unidirectionally curved retroreflective element, as opposed to planar retroreflective elements used heretofore.

Abstract: A concrete structure including a rigid three-dimensional lattice of concrete bars which are interconnected at nodes. The lattice is constituted by an assembly of prefabricated cast blocks, in which each block comprises a node and a plurality of arms (14) radiating from the node. Each arm has at least one longitudinal socket with an opening in the free end of the arm, and the arms of two blocks are assembled in aligned end-to-end pairs to constitute the bars of the lattice. The sockets of assembled arms are in alignment and contain a common metal reinforcing member, and the junction zone of the arms is surrounded by a clamping sleeve, with said sockets being filled with hardened mortar. The said lattice is prestressed by prestress cables passing outside the bars of the lattice and fixed to some nodes of the lattice.