Abstract: Silanes of the general formula ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 in the molecule are the same or different and represent aliphatic hydrocarbon groups,R.sup.4 is a divalent hydrocarbon group with 3 to 14 carbon atoms,R.sup.5 is a group having the formula --O(CH.sub.2).sub.b -- or a polyether group having the formula --(OC.sub.n H.sub.2n).sub.c --, whereinb has a value of 1 to 6,n has an average value of 2 to 2.5c has a value of 1 to 10, anda is 0 or 1, which fulfill the condition that they lower the surface tension of a 1% by weight aqueous solution to a value of .ltoreq.25 mN/m at 25.degree. C., measured with a Du Nooy tensiometer. The silanes are biologically degradable, resistant to hydrolysis and have pronounced surface active properties.

Abstract: A hydrostatic thrust bearing includes several bearing bushings and support bushings with axial spacer sleeves and radial flanges. Pairs of pressure surfaces to which oil can be admitted are arranged one behind the other in load application direction. The pressure surfaces of each pair of pressure surfaces are arranged frontally opposite each other. The thickness of the radial flanges of the bearing bushings is smaller than the radial flanges of the support bushings. The wall thickness of the spacer sleeves of the bearing bushings increases from bearing bushing to bearing bushing. The wall thickness of the spacer sleeves of the support bushings decreases in the same direction from support bushing to support bushing. Oil-conducting bores in the radial flanges of the support bushings ensure a uniform temperature level of the bearing bushings and support bushings.

Abstract: New, cationically curable oxyalkylene ethers and the synthesis thereof are disclosed. The oxyalkylene ethers, are of the general, average formula ##STR1## wherein R.sup.1 is an n-valent residual group derived from a compound (R.sup.1)H.sub.n from which n active hydrogen atoms have been split off and is capable of entering into an addition reaction with oxiranes, or a univalent alkyl or aryl group, and n.gtoreq.1;R.sup.2 is a hydrogen, hydrocarbon or R.sup.3 OCH.sub.2 -- group;R.sup.3 and R.sup.4 are each hydrogen, hydrocarbon or acyl groups, and R.sup.1, R.sup.2, R.sup.3 and R.sup.4 may have different meanings in the molecule;R.sup.5, R.sup.6 and R.sup.7 are each hydrogen or alkyl groups with 1 to 8 carbon atoms, or R.sup.5 and R.sup.7, or R.sup.6 and R.sup.7 together are a constituent of a cyclic, non-aromatic hydrocarbon group with 5 or 6 carbon atoms;m is at least 1 and at most n;x is the average molecule=3 to 100, andy in the average molecule=0 to 100, provided that 3.ltoreq.x+y<150.

Abstract: Polyacrylate esters with ammonium salt groups obtained by the transesterification of alkyl polyacrylates produced by free radical polymerization are disclosed, wherein the alkyl groups of the acrylate esters have 1 to 8 carbon atoms, up to 50% of the acrylate esters can be replaced by the corresponding methacrylate esters and the transesterification is carried out witha) compounds of the formula ##STR1## b) saturated or unsaturated aliphatic alcohols having 8 to 22 carbon atoms or alkoxylated alkylphenols having 9 to 27 carbon atoms in the alkylphenol group,wherein the molar ratio of component a) to component b) is 1:9 to 9:1, in such amount that 5 to 70% of the ester groups are transesterified and subsequently, the transesterification product is transformed into a salt.

Abstract: The invention relates to an apparatus of and a method of assembling a friction clutch structural unit wherein the clutch housing is centered with a cylindrical portion on a cylindrical guide of the flywheel and the axially correct position is found by axial application and measurement of the initial tension of the clutch main spring and the clutch housing and flywheel are rigidly connected to one another in this state.

Abstract: Aircraft cabin stairs to connect the aircraft fuselage to a parking area surface gave a frame comprising at least two telescoping segments as well as steps located in the region of the frame. An end segment forms part of the frame by means of side stringers which are present at least in certain regions and which are connected in a telescoping manner to side stringers of a main segment. At least one step in the region of the main segment is mounted such that it is free to slide in the direction of the stairs' longitudinal axis.

Abstract: A description is given of equipment for the production of screw-threaded drilled holes (tapped holes) of variable diameters in solid materials in a single-pass operation with the use of an integrated cutting tool and with the use of a commercially-available hand-drilling machine having an electronically-controlled motor drive, or any other type of drive, where the equipment includes a tool spindle which may be attached to the drive shaft of a hand-drilling machine or the like, and which is radially displaceable in relation to its axis and accommodated in a cylindrical housing for the spindle, where the position of said spindle housing may be adjusted axially in a specified manner by means of a screw device in a holder which may be mounted on the tool and has arrangements, on the one hand, for limitation of the axial travel of the tool and, on the other hand, for adjustment of the desire diameter of the tapped hole which is to be produced.

Abstract: The invention relates to a vacuum cleaner with a suction tube nozzle unit, consisting of suction hose, handle, suction tube and suction nozzle, the suction nozzle unit being releasably connected to the vacuum cleaner housing by a coupling device.

Abstract: A device for measuring the strength of pieces of compressed molding material. The device includes a probe pin and a stop surface arranged on the housing. On the end of the housing opposite the probe pin is arranged a cover for replacing batteries arranged within the housing. When the probe pin is inserted into the compressed molding material, a digital display indicates the resistance to insertion measured by a crystal unit converted as molding material strengths in N/cm.sup.2 or PSI.