Abstract: The invention relates to a vacuum ejector (1) is provided that includes a nozzle (4) for directing a jet of compressed air onto the center of a plate (5) which functions to deflect the compressed-air jet radially outwards at an angle of 90° in all directions, past a plurality of apertures (12) provided in the plate at a determined distance from the center (11) thereof. Each aperture (12) communicates with an associated suction cup (2) through the medium of a respective duct (14), for conducting the subpressure generated in the apertures (12) to respective suction cups (2).

Abstract: The invention relates to a vacuum hoisting device of the kind having a vertically suspended lifting tube (4), which is extensible and contractible depending upon the air pressure in the lifting tube, and which at its lowest part is provided with a suction device (6) in the shape of one or more suction cups. Up to now, a valve at the suction device has been used for maneuvering the suction device, which valve when closed brings a vacuum source (7,20) to work with a constant suction capacity to decrease the pressure in the lifting tube such that an object (32) to be lifted is attached by the suction after which the lifting tube is contracted such that the object is lifted. To limit the lifting height and to lower and release the object, it has been necessary to partially open the valve and permit a restricted inlet of air and at last completely open the valve resulting in a large consumption of air.

Abstract: A rotor for a screw rotor machine, which rotor comprises a metal shaft (3, 13) and a rotor body (1) of plastics material moulded on the shaft, which is provided with a number of radially extending projections (4) with equal distribution around the shaft, which projections (4) are provided with essentially peripherally extending wings (5) originating from the ridge of the projections (4).

Abstract: An arrangement in combustion chamber surfaces of an internal combustion engine, wherein these surfaces exhibit at least partially a thin surface layer (2) which will influence the octane/cetane rating requirement of the engine in a manner to limit the knocking tendency of the engine. The surface layer (2) comprises a material of low reflectivity and high absorptivity in respect of electromagnetic waves having a wavelength of up to at least 7 .mu.m. The surace layer (2) has located therebeneath a layer (3) which functions as a transient heat buffer and alternately absorbs heat from and emits heat to the surface layer (2).

Abstract: In a spark-ignition internal combustion engine of the type having a combustion chamber which presents at least one surface area on which there is applied at least one layer which presents to the combustion chamber a layer defining surface having very low reflectivity to electromagnetic waves in the wavelength range of about 0.2-7.0 microns. The layer reflects non-absorbed incident waves in a diffuse fashion, thereby to reduce the octane number requirement of the engine. The total surface area thus treated for each combustion chamber of the engine is equal to at least 10% of the top surface area of the piston in said chamber. The overall efficiency of the engine can be further improved when at least one of the layers has an underlying defining surface distal from the combustion chamber which reflects substantially all incoming electromagnetic waves in the wavelength range above 2.5 microns in a diffuse fashion.