Abstract: A differential pressure switch particularly suitable for monitoring dirt accumulation on a filter element of an oil-separating air filter comprising a piston which is movable in response to a relative change in pressure between two pressure zones and is biased in one direction by a restoring spring, and a rolling membrane which separates the pressure zones.

Abstract: For a squirrel-cage rotor of an electric machine, having a cage that passes through the stack axially and is made of electrically well-conductive short-circuit rods that are connected by short-circuit rings at the ends projecting from the stack, oscillation problems that result during operation with frequency converters are intended to be solved. In addition, higher natural torsion frequencies are intended to be achieved on the rotor, that is, the construction is to be made less sensitive by simple modifications to the squirrel cage in order to prevent the resonance effects. This object is attained in that respectively two, three or more short-circuit rods are guided together to rod assemblies at their ends, and these are connected to the short-circuit rings with material-to-material bonding.

Abstract: An apparatus for converting an optical wave having a relatively smaller cross section into an optical wave having a relatively larger cross section which may be manufactured in a monolithically integrated fashion in a simple way. In this apparatus, a wave-guiding, rib-shaped taper having an end for coupling the optical wave with a small cross section into the taper is fashioned on a rib of a rib waveguide which guides the optical wave. An optical wave having a larger cross section is fashioned thereon in a longitudinal direction of the rib. The infeed end of the taper and the taper itself has a smaller breadth in comparison to the breadth of the rib of the rib waveguide. Proceeding from this end, the taper broadens and decreasingly tapers in thickness in the longitudinal direction of the rib waveguide.