Abstract: A measuring carriage for a linear measuring system comprises a measurement sensing entrainment block arranged outside a tubular protective housing defining an interior chamber and a slot sealed by sealing lips in one side thereof. The block comprises a tongue projecting into the interior housing chamber through the slot. Support parts for carrier plates in the interior housing chamber are connected to the entrainment block by the tongue, and the carrier plates hold terminals generating electrical signals derived from sensing a measuring scale by the entrainment block. A connecting cable is attached to, and leads from, the entrainment block, and wires connect the signal generating terminals to the connecting cable, the wires passing from the signal generating terminals to the entrainment block and the connecting cable through a recess in the tongue. The tongue comprises complementary halves which may be fitted together to define the recess therebetween.

Abstract: An angle encoder having bovine an incremental section and an absolute section and serving to detect angular positions of an encoder disk and the number of revolutions performed by said disk comprises an incremental measuring scale and an absolutely coded measuring scale provided on said disk and associated reading and evaluation means. In conjunction with a high angular resolution it is desired to determine any absolute position of the disk without a previous rotation of the disk. This is accomplished in that the encoder disk comprises in addition to an incremental scale an absolutely coded scale consisting of a serial bar code, from which multidigit code words are readable, which are associated with respective absolute angular positions of the disk. The absolutely coded measuring scale extends on a track that is radially offset from the incremental scale and comprises code bars having side edges which are radially aligned with the radial boundaries of the increments of the incremental scale.

Abstract: In a system comprising a laser diode and means for stabilizing the wavelength of a primary beam of light emitted by said laser diode said means comprise a controller for controlling the current supplied to the laser diode under the control of sensor means, which are responsive to the instantaneous ambient conditions and operating parameters, a beam splitter, which is disposed in the path of said primary beam and arranged to divert from said primary beam a partial beam to measuring means, which comprise a diffraction grating and associated focusing optical means and are arranged to direct said partial beam onto photodetector means and to form on said photodetector means a light spot having a position and/or size depending on the instantaneous wavelength of said primary beam. The photodetector means serve to detect deviations of the light spot from a desired position, which is associated with the rated wavelength of said primary beam.

Abstract: A system for measuring lengths or angles comprises a scale member provided with absolutely coded scale elements and incremental scale elements, a movable scanning unit generating position-dependent signals in response to the reading of the scale elements, and an evaluating unit for determining the absolute position of the scanning unit relative to the scale member in response to the position-dependent signals. The coded scale elements consist of different code words arranged according to a serial code and are read by a multiline detector which, in any position of the scanning unit relative to the scale member, reads at least an entire code word.

Abstract: A length measuring system comprises an elongate scale member adapted to be scanned for generating measured-length signals, a tubular scale member carrier defining an internal cavity housing the scale member and including a mounting wall, a connection of the scale member to the scale member carrier, the connection permitting a longitudinal movement of the scale member relative to the scale member carrier, and end blocks rigidly connected to the scale member carrier at both ends thereof, the end blocks defining recesses and having opposite sides.

Abstract: A tubular protective carrier housing for a length measuring system encased in the carrier housing, the housing having a longitudinal axis and comprising two end parts extending from respective sides of a center part, and fastening devices at the center and end parts for affixing the carrier housing to an object, the housing and the object being subject to thermal expansion. To simplify the structure, the carrier housing itself comprises a length equalizing element at the center part for compensating for differences in the thermal expansion of the housing and object.

Abstract: In a photoelectric position detector a scanning movement of a scanning phase grating relative to a scale member which is provided with a reflective phase grating is detected, light emitted by at least one light source is diffracted by the scanning grating and as it is reflected by the scale member and then again by the scanning grating to form an interference pattern and only groups belonging to said interference pattern and being of a predetermined diffraction order are detected by respective photodetectors and are converted by them to phase-displaced photodetector signals, which are cyclically changed as the scanning grating is moved relative to the scale member.

Abstract: A length measuring apparatus comprises a measuring device for detecting the position of a marker along a measuring path. The measuring device and the marker are encapsulated in a hermetically sealed housing. A follow-up device is provided for moving the marker to a predetermined position of registration relative to a detectable point, which is disposed outside the housing and is movable along a path which is parallel to and laterally aligned with the measuring path. The follow-up device comprises a device for establishing a non-contacting link between the detectable point and the marker. To provide such an apparatus which has a relatively simple design and a low susceptibility to disturbance and can achieve a high accuracy of measurement. The apparatus comprises a strip that is trained around reversing end pulleys and has a course that extends along the measuring path. The marker is carried by the course.

Abstract: In an incremental measuring system a measuring scale provided on a scale member is scanned, periodic, basically sinusoidal analog measured-value signals are generated as a result of said scanning, and digital countable signals, which depend on the direction of the scanning movement, are derived from said analog measured-value signals and are delivered to evaluating means, such as indicating or control means. Electronic means are provided for correcting errors consisting at least of defects of the scale or of the positioning of the scale member in accordance with a stored or predetermined correction program.

Abstract: In the operation of an incremental measuring system, a measuring scale is scanned for generating periodic sinusoidal, analog measured-value signals. Digital countable signals are derived from the measured-value signals in conjunction with an electronic subdivision of the scale and are delivered to an electronic evaluating unit. Each countable signal is associated with a certain phase angle of the measured-value signals.

Abstract: The incremental measuring system comprises a scale member with an incremental scale and a scanning unit comprising scanning sets for generating analog measured-value signals in response to the scanning of the scale. The system also comprises an evaluating unit for deriving digital countable signals from the analog measured-value signals and for generating a reference pulse. At least one pair of reference marks are spaced along the scale on a carrier releasably fixed to the scale member. The scanning unit comprises a reference mark scanning set to scan the reference marks and connected to the evaluating unit. A reference point which registers with a selected increment of the scale is disposed on the carrier between the reference marks of the pair and can be defined by the distances from the reference point to the reference marks, and these distances are stored in a memory.

Abstract: The length measuring system comprises a scale member provided with a scale and a scanning unit, which is movable along the scale and is guided by the scale member or by separate tracks, which are parallel to the scale and is coupled to an actuating member by a backlashless coupling. The two coupling elements of the coupling cross each other and are in point contact with each other and having engaging surfaces which are centered on axes which are normal to the longitudinal direction of the scale member. A backlash of the coupling is prevented by a permanent magnetic biasing set, which comprises parts which are respectively connected to the actuating member and to the scanning unit and consist of two permanent magnets or of a permanent magnet and an armature.

Abstract: A method of digitally measuring displacement increments in which, for the relative displacement of a scanner and a scale having regularly spaced graduations each defining an increment of displacement, correction values and the signals are stored at respective addresses corresponding to the relative displacement and respective locations on the scale, only where the correction exceeds a predetermined threshold value. During the measurement, the measured values, which can correspond to each graduation and to interpolation values between each graduation and the next graduation to be scanned, are corrected with the corrected value addressed as each location is reached.

Abstract: A scanning unit is movable relative to a scale member and is connected to a fiber optical system for illuminating a reading unit with light that has been emitted by at least one light source and transmitted by the fiber optical system to the scale member. The reading unit is connected by a fiber optical system to the scanning unit and comprises optoelectronic receivers for converting the optical signals to electric signals. It is desired to use basically the same reading and illuminating units with different scale members and to use fiber optical systems also with coding scales and high-accuracy incremental scales. At least the reading fiber optical system which connects the optoelectronic receivers to the scanning unit consists of an image-transmitting, directive fiber optical system, which has a receiving area facing the scale member. Reading aids are disposed between the opposite end of said reading fiber optical system and the optoelectronic receivers.

Abstract: A sealed instrument for measuring lengths comprises a carrier, a scale mounted on said carrier, and an optoelectronic scanning unit including a scanning plate, light emitters and light receivers. The scanning unit is adjustable along the scale by means of a feeler, which includes an actuating member. A correcting device is provided, which includes a deformable correcting template and a template follower for scanning the correcting template and for adjusting the scanning plate relative to the actuating member in the direction of the scanning movement. In order to reduce the overall expenditure, to simplify the correction and to increase the reliability of operation and the accuracy of the measurement, only the scanning plate is operatively connected by an adjusting mechanism to the template follower and is adjustable relative to the remaining parts of the scanning unit in dependence on the configuration of the correcting template.

Abstract: The scanning unit which is movable along the scale member comprises signal-generating means, which are accommodated in one or more covering hoods. Each covering hood has an annular boundary surface facing the scale member and is provided at said boundary surface with an annular seal which consists of elastomeric material and is in sealing contact with the scale member under initial compressive stress throughout the peripheral extent of the boundary surface. The covering hood and the scale member thus define between them a measuring chamber in which the atmospheric conditions are favorable for an accurate measurement. As the scanning unit is moved along the scale member, the measuring chamber will always be disposed at a portion of the scale member in which the surface of the scale member has just been cleaned by the sliding contact between the annular seal and the scale member.

Abstract: The incremental measuring and machine control system comprises an incremental scale and an auxiliary track extending beside said scale along the same and provided with at least one reference mark in register with a predetermined point of said scale. A scanning unit comprises scanning means for scanning said scale and for generating analog signals in response to the scanning of said scale. The scanning unit comprises additional scanning means for scanning said reference marks and for generating reference signals in response to the scanning of the reference marks. A processor derives digital signals for said analog signals and delivers the digital signals to a counting or display unit which is controlled by said reference signals or by signals derived therefrom.

Abstract: A linear measuring system comprises an elongate housing tube, which contains a metal strip, which is provided with a scale. The housing tube contains also a scanning unit, which is movable along the scanning tube to scan said scale. To ensure that the metal strip will be uniformly tensioned throughout its length and that the accuracy of the scanning operation will not be affected by a deviation of the longitudinal direction of the housing tube from a desired direction in which the measurement is to be taken or by changes of the length of the housing tube, the metal strip extends in the housing tube substantially without a longitudinal restraint and extends at both ends out of the housing tube and is held at said two ends by brackets, which are disconnected from the housing tube. In the housing tube, the side edges of the metal strip are entirely clear of the housing tube.