Abstract: In a drive unit which has an axial piston pump and an electronic control unit, the axial piston pump is pivoted with a method in which pressure-reducing valves which act in opposition to one another are suddenly energized. Since in this respect no orifices are provided in the adjustment device, a so-called initiation jump of the excited current gives rise to a sudden reduction in the assigned actuating pressure or the actuating pressure difference formed therefrom. Then, a zero crossover jump of the excited current or of the excited currents is carried out in order to overcome the centering spring and therefore ensure a continuous zero crossover of the axial piston pump. Furthermore, a hydrostatic traction drive includes such a drive unit.

Abstract: In a drive unit which has an axial piston pump and an electronic control unit, the axial piston pump is pivoted with a method in which pressure-reducing valves which act in opposition to one another are suddenly energized. Since in this respect no orifices are provided in the adjustment device, a so-called initiation jump of the excited current gives rise to a sudden reduction in the assigned actuating pressure or the actuating pressure difference formed therefrom. Then, a zero crossover jump of the excited current or of the excited currents is carried out in order to overcome the centering spring and therefore ensure a continuous zero crossover of the axial piston pump. Furthermore, a hydrostatic traction drive includes such a drive unit.

Abstract: A hydrostatic traction drive includes a hydraulic pump for supplying pressure medium to a hydraulic motor of the traction drive. The hydraulic pump has an actuation cylinder with at least one cylinder space and a swept volume which can be adjusted thereby. At least one electrically actuable pressure valve is provided, by means of which an actuation pressure which has an adjusting effect can be applied to the cylinder space. In addition, the traction drive has a device by means of which a pressure of the hydraulic pump can be limited by influencing the actuation pressure.

Abstract: The invention relates to contact strip (16) for slipping over the edge (22) of a wall unit (14), whereby a longitudinal edge (20) of the contact strip is designed cliplike and the contact strip has contact areas (24) bent out of the plane of the strip. The contact areas are formed by a single row, spaced apart from each other, contact tongues (24), stamped and bent out of the plane of the contact strip and by the cliplike longitudinal edge formed with a row of individual clip elements (20) distributed over length of the strip and spaced apart from each other.

Abstract: The invention relates to a viewing screen unit (2) with a viewing screen housing (6) supported swivelably around a swivel axis (4). The viewing screen housing (6) has the shape of a circular cylinder segment, where the viewing screen plane essentially coincides with the intersecting plane (10) of the circular cylinder segment and the pivot axis (4) coincides with the cylinder axis. In a preferred embodiment, the viewing screen housing (6) is fastened swivelably onto a receiving housing (8) containing at least part of the components. The receiving housing (8) is provided with a concave recess (19) turned toward the viewing screen housing (6), which recess fits closely against the curved rear wall of the viewing screen housing. The supporting of the swivelable viewing screen housing is preferably done by supporting means which act on either the inside of the end faces or on the curved back side of the viewing screen housing (6).

Abstract: A tape guide having a surface over which a tape is guided. The surface is formed by a coherent network of intersecting ridges whose tops form a smooth continuous surface having a regular pattern of discrete recesses in the surface.

Abstract: A mount for a projector or the like has a base with a convex spherical bearing element rotatably mounted therein and having a guide slot on the convex surface and a concave support rests thereon with a depending pivot pin disposed in a tapered aperture in the bearing and a projection fitting in the guide slot for limiting tilting of the support.

Abstract: A magnetic tape cassette for a tape recorder, having at least one erase interlock device including an actuating member movable over a defined path in the cassette between a operating position in which an opening in the housing is uncovered, and a position in which the opening is closed. The cassette includes at least one latching element preventing movement from a third position and either of the first two positions. Preferably the latch is movable, and in addition the interlock may be set in a fourth position from which it can be moved only upon disassembly of the cassette.

Abstract: A tape hub connection assembly, and a magnetic tape cassette containing such an assembly, in which an end of a length of tape is fixed to a reel hub by a clamping member pressed into a hub recess. The clamping member has a tool recess extending radially from the outer wall, for engagement by an assembly or an extraction tool so that the member is easily put in place or removed by a tool extending radially between the reel flanges.

Abstract: A magnetic tape cassette of the "flip-over" type having side-by-side reels in a housing between two parallel main walls, an exposed run of tape along a front of the cassette housing, and a pivoting cover for the exposed run of tape. A single cassette cover covers the entire front of the housing, and has a pivoting arm at each side which is journalled to the cassette housing sidewalls such that the cover can be opened from its closed position in either direction to two different open positions, by pivoting toward the one or toward the other main wall of the housing. A movable slide may also cover openings which provide access behind the stretch of tape.

Abstract: A magnetic tape drive system for a video cassette recorder comprises a flip-over magnetic tape cassette having side-by-side reel hubs, each hub having a disc-shaped centering and drive member in the center of the hub with a central centering aperture and one or more drive apertures at some radial distance from the centering aperture, and a drive arrangement with drive spindles having a centering pin for the centering aperture in the reel hub, and at least one resiliently depressable drive pin which engages a drive aperture. To ensure correct positioning and drive of the spools and an excellent lace-up, and prevent undesired variations in the tensile stress in the magnetic tape and thus variations of the stretch of the magnetic tape, the reel hubs are resiliently urged onto stop surface which rotate with the drive spindles. The resilient urging devices and drive apertures are arranged to prevent disturbing forces on the reel hub.