Abstract: A multi-turn rotary encoder that includes a first code carrier connected with an input shaft, a scanning device that scans the first code carrier and generates an absolute position of the input shaft within one revolution, and a digital code word is present at an output of the scanning device and a second code carrier for measuring the number of revolutions of the input shaft. A reduction gear is arranged between and coupled to the first and second code carriers. The second code carrier includes a magnetic body with at least one north and south pole and a substrate with a spatial arrangement of sensor elements integrated therein, which are sensitive to magnetic fields, is associated with the magnetic body.

Abstract: A position measuring system that includes a scale graduation and a scanning element, wherein the scanning element moves relative to the scale graduation along a measurement direction so as to generate position-dependent, intensity-modulated output signals. The scanning element includes a dynamic characteristic, which has saturation areas adjoining both sides of an at least partially approximately linear operating area, in which no significantly changed output signal results any more, even when the input signal changes. The scanning gap (d) between the scale graduation and the scanning element is selected in such a way that as the scanning element moves over its entire measurement range a modulation between maximum input signals, which are located in the saturation areas of the dynamic characteristic, takes place.

Abstract: An arrangement as well as a method for the automatic correction of error-containing scanning signals, which contain defined deviations from the ideal signal shape, of incremental position measuring devices is disclosed, wherein an ideal signal shape is presupposed by a downstream arranged evaluation unit. In this case the scanning signals are supplied to a processor unit, and correcting values are determined by means of a correction algorithm which are converted in turn into appropriate control signals. The analog scanning signals as well as the control signals are supplied to a correction unit, which contains several adjustment possibilities for correcting the error-containing scanning signals by the control signals acting on them. The processor unit as well as the correction unit are arranged in such a way that scanning signals, which have already passed through the correction unit, are present at the input side of the processor unit.

Abstract: A position measuring device having a magnetic graduation scanned by a scanner unit which contains magnetic field sensitive elements as sensors. A high frequency alternating auxiliary field is generated to magnetically bias the magnetic field sensitive elements.

Abstract: In a magnetic position measuring device for determining the relative position of two objects which can be moved with respect to each other, a magnetic graduation is scanned by at least two Hall elements for the generation of position-dependent output signals. The Hall elements respectively have at least one supply voltage and one measuring voltage connector. Furthermore, at least one switching unit is provided, which periodically interchanges the supply voltage and the measuring voltage connectors of each Hall element with each other. The periodic interchange of the supply voltage and measuring voltage connectors of the various Hall elements with each other is furthermore synchronized by means of at least one synchronization unit.

Abstract: A measurement representation with magnetic elements disposed in the measuring direction, comprising fitted-together base bodies, wherein all magnetic elements of each base body are magnetized with the same orientation in one single common direction, and that the fitted-together measurement representation has alternatingly a magnetic element of a base body and of a further base body, wherein the magnetic field of the magnetic elements of the one base body is oriented opposite the magnet field of the magnetic elements of the other base body in the fitted state.

Abstract: A position measuring device having a sensor, the output signal Sd of which is a function of the distance between a graduation and a scanning unit. To render the distance-dependent signal independent of temperature changes, the sensor consists of a potentiometer circuit with an active branch and a complementary branch. Magneto-resistive elements which scan the graduation are disposed in the active branch. Resistive elements are disposed in the complementary branch which have the same temperature behavior as the magneto-resistive elements of the active branch, but are substantially insensitive to magnetic fields. The voltage across the active branch is taken as the distance-dependent measuring signal Sd and is used to control the amplitude of the position-dependent scanning signals generated by scanning the graduation.

Abstract: A magnetic measuring system having a scale and a scanning unit, the scanning unit having a plurality of magneto-resistive elements which are disposed at an angle .beta. with respect to the measuring direction. The scanning unit generates an auxiliary magnetic field which acts perpendicularly to the measuring direction so as to magnetically bias the magneto-resistive elements.

Abstract: A position measuring instrument for measuring the relative position of two objects movable relative to one another. The position measuring instrument comprises a periodic measurement scale division having a period t and a scanner unit, wherein the scanner unit and the periodic measurement scale division move relative to one another in a measuring direction. In addition, the scanner unit comprises four groups (A-D) each comprising at least four magnetoresistive elements (A.sub.n -D.sub.n) (n=1, 2, 3, 4, . . .), which are interconnected in the form of a series-parallel circuit to form a half bridge circuit having an upper branch and a lower branch. The upper branch comprises a magnetoresistive element from each group (A-D) and the lower branch comprises a corresponding magnetoresistive element from each group (A-D). Furthermore, the magnetoresistive elements of the upper branch are offset from the corresponding magnetoresistive elements of the lower branch by t/2.

Abstract: A phase grating is provided in this length or angle measuring apparatus, which operates by interference. A beam striking the phase grating from a laser is diffracted into .+-.1st order beams at the phase grating. The diffracted .+-.1st order beams are reflected at retroreflecting elements and, diffracted once again at the phase grating, and made to interfere in pairs. The modulations in intensity of the two-beam interferences are converted by detectors into electrical signals that are phase-displaced from one another. The diffraction grating is configured such that at least one partial beam cluster of the zero order of diffraction is involved in the formation of at least one of the two-beam interferences.

Abstract: The angular graduation of a graduated disk is scanned in a measuring device by a scanning unit by the movement of light beams in two angular graduation areas located diametrically opposite each other. To compensate for wobble errors caused by the wobbling of the graduated disk, the light beam emanating from a light source impinges on the graduated disk at a point outside of the angular graduation and, following reflection and deflection by a triple prism, impinges parallel to itself in the form of a light beam on an impact point in a first the graduation area. The light beam is split into two diffraction beams by the graduation, and meet, after having passed through a deflection prism, at a meeting point in a second angular graduation area. Since the impact point and the meeting point are always located on the same radius, the wobbling of the disk does not have a disadvantageous effect on the accuracy of measurement.

Abstract: A position measuring arrangement is disclosed which comprises a three-grid measuring system. A first grid is illuminated under an angle .alpha.. Two partial beams result from diffraction on the first grid. the two partial beams impinge on a second grid, which may be the scale of the position-measuring arrangement. Diffraction of the partial-beams on the second grid result in four partial-beams of which the two partial-beams lying closest to the grid normal impinge upon a third grid. The third grid again diffracts the partial-beams and brings them into interference. The partial-beams which are intensity-modulated by interference by the third grid impinge upon photodetectors, by which they are transformed into phase-shifted electric signals and fed to and evaluated arrangement.

Abstract: A measuring system is disclosed which is integrated into a feed arrangement in such a way that the structural size of the feed arrangement is not increased significantly. In the disclosed embodiments, the feed arrangement includes a compressed air cylinder which includes a hollow profile and a piston movable within a cylinder defined by the profile. In one embodiment, a measuring scale is positioned within a groove formed within the hollow profile and this measuring scale defines a magnetic measuring graduation which is scanned by a scanning unit accommodated in the piston of the air cylinder.

Abstract: In a photoelectric measuring device for measuring the position of two objects which can be rotated relative to each other, a grid located on a graduation support, which is connected with one of the objects, is scanned by a scanning device connected with the other object. To eliminate the eccentricity between the grid and the rotational axis of the graduation support, the light beam emitted by a light source is split in a first graduation area of the grid into two first order diffraction beams, at two diffraction angles. After two-fold deviation by two parallel mirrors, the first order diffraction beams are again joined, in a second graduation area of the grid that lies diametrically opposite the first graduation area. The first order diffraction beams join at the same diffraction angles at which they were emitted from the first graduation area of the grid. Consequently, the beams at the second graduation area are parallel to themselves as they were emitted at the first graduation area.

Abstract: A magnetic measuring instrument for measuring the relative position of two objects includes a scanning unit which incorporates a magnet positioned to scan a measuring division. The measuring division is provided with alternately magnetically conducting and magnetically non-conducting zones. Measuring signals of high signal quality are generated because the induction generated by the magnet in the measuring division runs only in planes perpendicular to the longitudinal extent of the measuring division (the measuring direction x). Magnetic field sensitive sensor elements in the air gap between the magnet and the measuring division scan the air gap induction to generate position dependent measuring signals.

Abstract: A process and apparatus for obtaining harmonic-free periodic signals in an incremental measuring system is disclosed in which a graduation having a graduation period P is scanned by at least six scanning elements (for the case in which the previously determined bandwidth N of the analog signals obtained in scanning the graduation N is equal to 3). The periodic analog signals generated by the scanning elements are subjected to a Fourier analysis for the determination of the Fourier coefficients of the base or fundamental wave of the periodic analog signals. These Fourier coefficients are then evaluated as harmonic-free periodic signals for the formation of position measuring values.

Abstract: An error correction system for correcting machine errors or division errors in a position measuring instrument for precision machines is disclosed. The system is usable, for example, in conjunction with instruments for measuring the relative position of two objects, wherein an incremental grid division formed on a measuring scale is scanned by a scanning unit to generate analog measurement signals. According to this invention, the scale defines additional correction tracks which extend along the scale, parallel to the division, and are scanned by additional scanning elements included in the scanning unit. These additional scanning elements operate to generate analog correction signals from the correction track. These analog correction signals are used to correct the analog measurement signals with respect to errors such as amplitude errors, phase angle errors, and zero crossing errors.

Abstract: A gas bearing for textile machine applications includes a rotor having a bearing surface shaped to define a truncated conical bearing surface and a foil shell having a corresponding truncated conical shape. This gas bearing supports both radial and axial loads, and two such bearings may be combined to support axial loads in two directions as well as radial loads.

Abstract: A gas bearing for rapidly rotating parts, particularly in textile machines, including two support members mounted on a base plate, thin foils attached to each of the support members by means of clamping plates such that the foils partially embrace a rotor shaft or other part to be positioned, and a drive belt which rotates the rotor shaft and maintains the shaft positioned against the foils. Additionally a movable hose is attached to a foil whereby gas can be introduced between the rotor shaft and the foil by means of perforations in the foil. A similar supporting gas film is created at an end of the rotor shaft. Centrally located axial passages in the rotor shaft and a positioning magnet introduce gas into the shaft and through radial ducts in the shaft to provide a thin gas film for supporting the shaft. According to a further embodiment a gas bearing is provided for use with a shaft which is driven independently of the bearing.

Abstract: A planar measuring instrument is disclosed for determining the deviations from the straightness or planeness of parts, the instrument including a laser beam and a measuring sensor which is displaceable transversely to the measuring direction, both of which are enclosed in an elongated, preferably evaculated, hollow body. In one disclosed embodiment, the laser beam impinges on a photo detector associated with the planar sensing bolt whose output signals cooperate with an electromagnet associated with the planar sensing bolt to compensate for guidance errors. In another series of embodiments, the laser beam is separated into partial beams. One of these partial beams impinges on reference detectors located at the end of the measuring path with the output of said reference detectors being used to drive a servo system which adjusts the direction of the laser beam and reference line determined by it. The other partial beam is used for cooperation with the measuring sensor system.