Abstract: Individual single crystal elements stacked one above the other are aligned with their optical (Z) axes parallel to each other, and are provided with contact electrodes on opposite surfaces normal to their electrical (X) axes. Contact electrodes of the same polarity are conductively connected by two bridge electrodes that are applied to opposite sides of the assembled stack of individual crystal elements in the form of a conductive coating, and are provided with a lead leaving the sensor element. Contact electrodes of the opposite polarity are recessed in the vicinity of the bridge electrode serve the other polarity.

Abstract: The balancing weights of the engine are directly mounted on the camshaft which is driven from the engine crankshaft in a counter-rotational sense, using a pair of gears and a simple toothed belt. This simple design saves both space and weight.

Abstract: A known feature of internal combustion engines is that the cooling-water pump has an impeller which is rigidly connected with a squirrel cage rotor and which is driven without physical contact via the rotatory field of rotating permanent magnets. If such an engine is additionally provided with a flywheel generator, construction of the cooling-water pump is greatly simplified according to this invention, as the permanent magnets of the flywheel generator are simultaneously utilized for driving the impeller, and the water pump is positioned in a concentric recess of the flywheel, thereby saving space.

Abstract: A water-cooled internal combustion engine powering the vehicle is mounted in an engine compartment comprising a sound-insulating capsule. Independent of and additionally to any possible blower ventilation of the capsule at least one separate inlet opening into the capsule is connected to an intake opening situated in an area which is exposed to dynamic pressure when the vehicle is in motion. The front cross-member may be provided with an intake opening open in the direction of motion as well as with a sound-absorbing lining, and the inflowing cooling air may be fed into the capsule via the adjacent longitudinal beams of the vehicle frame.

Abstract: In a motor vehicle a water-cooled internal combustion engine serving as the driving engine is enclosed by a sound-absorbing capsule partly formed by the surrounding parts of the vehicle. At the front wall of this capsule a housing is provided to receive the air flowing off from the radiator, from which housing a closed air duct passes through the capsule, leading into the outside at one of the other capsule walls.

Abstract: A test volume and a reference volume are irradiated by separate beams of an infrared source, and the two beams are subsequently fed to a detector in periodical alternation. The time constant of the detector is small compared to the period of this alternation. From the measured differences in intensity the masses of the absorbing components of a sample in the test volume are determined. During each period the value of the detector signal is sampled by an evaluation unit at least once while either the test beam or the reference beam is being present at the detector. For separate determination of different sample components, radiation of different defined frequency bands is fed to the detector during each period, and the intensity of the test beam is determined at each of the different frequencies whereas that of the reference beam is determined at one of these frequencies at least.

Abstract: For a continuous measurement of the mass of absorbing particles in a gaseous sample, the sample is traversed by electromagnetic radiation of a wavelength greater than the mean radius of the particles. The difference in absorption for at least two frequencies is determined and appointed to the particle mass sought after.

Abstract: An axial fan, preferably for the cooling systems of water-cooled internal combustion engines, comprises an impeller and an air duct housing provided with a fan guard which is separated by an annular gap from the tips of the impeller blades and is centered on the impeller axis by a support comprising radial arms attached to the fan guard. For noise reduction, the radial arms are supported on the hub of the impeller, on the side facing the fan shaft, by means of a roller bearing held by a mounting plate, and the mounting plate is made independent of the impeller bearing.

Abstract: An extraneously driven piston engine is fitted in the region of its valve ar with solid-borne vibration pick-ups which are connected to a processor unit. An angle-mark transmitter on the crank assembly controls a gate circuit which within specified zones of crank angle, feeds the vibration signals into a limit-value circuit which, by a comparison of levels, provides a "good/bad" information read-out.

Abstract: Three impulse transmitters are provided of which one co-acts with an impu mark on the flywheel, another with an impulse mark on the camshaft drive wheel and a third with the teeth of the ring gear on the flywheel of the engine. The impulse mark on the flywheel enables a precise determination of a reference angle position of the crank drive and the impulse mark on the camshaft pinion by triggering a window enables correct association within the working cycle which covers 720.degree. of crank-angle. The time spacing and amplitude of the triggered window are controlled by the tooth sequence on the ring gear.

Abstract: Capacitive measuring transformer, especially for small capacitance values, with two parallel bridge arms, connected with an oscillator, each of which has at least one capacitor, whereby a differential amplifier is provided which is connected on the input side with the bridge arms and the input of which is connected by a feedback circuit, containing passive elements only to one of the bridge arms. A control element (D.sub.1, D.sub.2) precedes every one of the bridge arms and a fixed potential or a potential changing inversely in relation the outlet of said differential amplifier, (OA.sub.1) is applied to the second bridge arm. As a result, one will moreover achieve a high measure of stability and linearity between capacitance and output voltage. The fixed potential is used when the feedback is to one bridge arm only. The potential changing inversely in relation to the output of the differential amplifier (OA.sub.

Abstract: A two cylinder engine has a reverse scavenging system with exhaust ports itioned on either front end of the cylinder block and directed towards areas without any ports which are located next to each other in the center of the engine. Intake ports are directed towards either side wall of each cylinder where they open into charge compartments which are closed, e.g., with covers whose dimensions will permit milling and core-pulling tools to have access to the intake ports. Between the port-free areas of the cylinders a gap is provided which connects the water jackets of the cylinders in the upper part and the charge compartments in the lower part thereof.

Abstract: An AC generator may be connected to the signal leads of a piezoelectric transducer in order to induce mechanical vibrations in the transducer via the inverse piezoelectric effect. For determination of the vibration characteristics of the transducer provisions are made for a subtraction unit, whose one input is fed with the excitation signal of the AC generator while the other input is connected to the signal leads of the transducer. An evaluation unit is connected to the output of the subtraction unit; it displays and processes the measurement signal derived as the difference of the response signal of the transducer and a signal proportional to the excitation signal.

Abstract: The device comprises an evaluation unit and at least one transducer for feeding the electric signal to this unit on the occurrence of a characteristic event and the evaluation unit comprises a recognition unit sensing the occurence of the characteristic event. To permit determination of the trigger point characterizing the occurrence of the characteristic event also in the case of heavily noise-contaminated measuring signals the evaluation unit is provided with one or several comparators in addition to the recognition unit, whose thresholds are spaced out over a certain range of levels, and--depending on whether the transducer signal has reached the threshold of the recognition unit--by using the information contained in the evaluation unit, which is influenced by the sequence of the comparator responses according to the signal shape delivered by the transducer, for determination of the trigger point characterizing the occurence of the characteristic event, in a manner predetermined in the evaluation unit.

Abstract: In order to improve in a simple manner the ventilation of a water-cooled internal combustion engine having a sound-absorbing cover, a suction device is provided at the air inlet opening of the cover, the suction device containing a suction port in the low pressure area of the radiator/fan assembly. By specific placement of several air inlet openings a variety of cooling requirements may be met.

Abstract: A pressure measuring device is provided with a change-over valve connecting the pressure sensor either with the pressure to be measured or with a reference pressure. The change-over valve is actuated by a separate control pressure and will protect the pressure sensor from the influence of the pressure medium to be measured in the spring-loaded idle position of the valve.

Abstract: In order to avoid the danger of overheating the separate exhaust jacket of a water-cooled internal combustion engine with a sound-absorbing cover whose enclosed space contains air inlet and outlet openings sealed against the penetration of sound, and is ventilated by cooling air during operation of the engine, and which has a separate exhaust jacket with air ducts of its own-with a radiator cooling fan being placed outside of the cover in the vicinity of a cover wall serving as a radial deflector for the outgoing air from the fan, and with the exhaust jacket leading substantially upwards from its outlet to its inlet opening-after the engine has been switched off and the forced ventilation has thus come to a standstill, the air inlet opening leading into the exhaust jacket is connected to the topmost part of this jacket and is positioned such as to be exposed to the flow of outgoing air from the fan.

Abstract: A partitioning circuit will partition into subintervals the time interval between two signals delivered by a recognition circuit, and will activate a gate circuit during one of these intervals which has been predetermined. In addition to the recognition circuit, the sequence of signals from a sensor responding to the occurrence of an at least approximately periodic event, is fed to a comparator circuit which will transmit a pulse to the gate circuit each time a certain signal level has been exceeded. If the gate is active, this pulse will be available for further processing.

Abstract: The measuring electrode to be checked is polarized cyclically with an alternating voltage and the maximum amplitude of the electrode current as occuring during cyclical polarization is directly used as a measure for the metrologically relevant condition of the electrode.

Abstract: An apparatus is disclosed, for measuring the angular position of a shaft of a machine at the occurrence of an event originating from the operation of the machine, relative to a reference position of the shaft. The apparatus comprises a first sensor responsive to the reference position of the shaft (signal II) and a second sensor which, on the occurrence of the event, produces an output pulse and which produces a number of interference pulses in the periods between production of the output pulses (signal I). A comparator (4) having a threshold value which is capable of being exceeded both by the required pulses and the interference pulses, and a recognition circuit (3,6) which is adapted to recognize output pulses produced on the occurrence of the event, are arranged to control an evaluation circuit such as a counter (10). The evaluation circuit ascertains, e.g.