Error Compensation (e.g., Temperature) Patents (Class 33/702)
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Patent number: 5650852Abstract: A temperature-compensated laser measuring method and apparatus for determining the dimensions of long parts is disclosed. Parts to be measured are positioned along a y-axis fence (19) against an x-axis fence (21). A gantry (15) is moved along a precision support rail (17) to the desired longitudinal (x-axis) position. Then a probe (23) is moved inwardly or outwardly to a desired y-axis position and lowered to a desired z-axis position. A Doppler laser measuring system that includes a Doppler laser head (25) and retroreflector (27) measures x-axis length. Y-axis and z-axis encoders (29, 31) determine y-axis and z-axis probe position with respect to the y-axis fence and the top (39) of the table (13). A temperature compensation unit (103) receives the laser measurement information and modifies the x-axis length measurement based on part temperature and the coefficient of expansion of the part.Type: GrantFiled: March 8, 1996Date of Patent: July 22, 1997Assignee: The Boeing CompanyInventors: William P. Chastain, Marc A. Garoutte, Eric J. Rogers
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Patent number: 5630283Abstract: An encoder including a measuring standard, a scanner for scanning the grating of the measuring standard, a measuring standard carrier having a groove for receiving the measuring standard, a relatively thin glue layer provided between one of the opposite surfaces of the groove and the measuring standard, and at least one spring element provided between another of the opposite surfaces of the groove and the measuring standard.Type: GrantFiled: April 3, 1995Date of Patent: May 20, 1997Assignee: Dr. Johannes Heidenhain GmbHInventor: Gunther Nelle
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Patent number: 5611148Abstract: In the position-measuring arrangement having a groove formed in a housing for the fastening of a measurement embodiment. So that different expansion coefficients of the housing and of the measurement embodiment will cause no measurement errors, the measurement embodiment is fastened longitudinally slidable with respect to the housing in the groove. This is achieved by providing in the zone in which the measurement embodiment is held in the groove a sealing compound. A separating layer is provided between measurement embodiment and sealing compound to provide longitudinal movement.Type: GrantFiled: March 2, 1995Date of Patent: March 18, 1997Assignee: Dr. Johannes Heidenhain GmbHInventor: Alfred Affa
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Patent number: 5581012Abstract: A method for the dimensional measurement of a piece to be checked is disclosed, wherein a comparison sample and a reference sample are employed, respectively of a material which is coherent with that of the piece to be checked and of a material having a low thermal expansion coefficient. Through the comparison between the two samples the relative thermal expansion is determined, and same is then related to the measurements carried out on the piece to be checked so as to determine the dimensions thereof as if the measurement were performed in a controlled temperature environment. The reference sample for carrying out the method is preferably made of a composite material.Type: GrantFiled: December 2, 1994Date of Patent: December 3, 1996Assignee: Rosfer Engineering Sas di Critelli Antonio e C.Inventor: Antonio Critelli
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Patent number: 5551163Abstract: The housing of a position measuring arrangement is fastened over length balancing elements to a first object such as a slide of a machine tool. A measurement embodiment is mounted over a highly elastic adhesive layer on an inner surface of the housing and is scanned by a scanning arrangement. In order to achieve a low-vibration fastening of the housing, it is supported in supporting zones formed between side surfaces of the housing and the exterior surface of the slide. The free length expansion between the housing and the slide is ensured by providing an elastic adhesive layer in the supporting zone.Type: GrantFiled: February 28, 1995Date of Patent: September 3, 1996Assignee: Dr. Johannes Heidenhain GmbHInventor: Alfred Affa
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Patent number: 5511321Abstract: A linear encoder for measuring a relative position of two objects and including a scale having a coefficient of thermal expansion between 2.5.times.10.sup.-6 K.sup.-1 and 3.5.times.10.sup.-6 K.sup.-1 approximately, and attachable to one of the objects, and a device for scanning the scale and attachable to the other of the objects.Type: GrantFiled: July 26, 1995Date of Patent: April 30, 1996Assignee: Dr. Johannes Heidenhain GmbHInventor: Gunther Nelle
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Patent number: 5446971Abstract: A method for compensating sliding temperature influences on workpieces during a dimensional measurement process. For this purpose, the workpiece temperature and the relative position of the workpiece in relation to the measuring apparatus are recorded at the start and at the end of the actual measurement. By use of the recorded values, the temperature of the workpiece can be calculated at each instant of the dimensional measurement and the relative position of the workpiece in relation to the measuring apparatus and therefore the corrected scanning point can thus be determined. Thus, in the dimensional measurement of workpieces, while taking into account the temperature influences, the temperature straight line in the time interval from the start of measurement to the end of measurement is divided by intermediate measurements into part intervals, within which interpolation can be carried out.Type: GrantFiled: January 14, 1994Date of Patent: September 5, 1995Assignee: Leitz Messtechnik GmbHInventor: Jan Neumann
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Patent number: 5408758Abstract: A system for compensating for spatial errors of a movable machinery having a three-dimensional spatial mechanism includes a command generator for generating a commanded coordinate value in the space of command; a position controller for operating in response to the commanded coordinates value as an input; a position detector for detecting the operating position set by the position controller on the space of motion as a coordinate value of the space of command; and a spatial error compensating unit for compensating for spatial errors between the space of command and the space of motion contained in the output coordinate value of the position detector, outputting a compensated coordinate value as a measured value and correcting the commanded coordinate value by use of the compensated coordinate value, and the spatial error compensation and the motion control on the compensated space of command can be realized by use of only one system of function generator.Type: GrantFiled: March 2, 1993Date of Patent: April 25, 1995Assignee: Mitutoyo CorporationInventors: Takashi Mizutani, Hiroshi Haino
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Patent number: 5375338Abstract: A length measurement device for measuring the relative position of two objects is disclosed wherein a graduation on a scale carrier is scanned by a scanning unit for obtaining measured position values. The scale carrier is connected to a first fixed reference point within the measuring length in a rigid manner, and is connected with a carrier member so as to be longitudinally displaceable, for compensating for measurement errors which are caused by temperature variation. The carrier member is rigidly connected with a first object at a second fixed reference point within the measuring length and is connected so as to be longitudinally displaceable with the first object 1. The first fixed point and/or the second fixed point are changeable or movable within the measuring length.Type: GrantFiled: April 8, 1993Date of Patent: December 27, 1994Assignee: Dr. Johannes Heidenhain GmbHInventor: Gunther Nelle
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Patent number: 5365674Abstract: A device for measuring the movement of a drill pipe string, the end of which is held during drilling by an attachment assembly (12) movably along at least one guide rail (16), comprises a sensor assembly (38) mounted on the attachment assembly with a roller (42) designed to run on the rail as the attachment assembly moves.Type: GrantFiled: December 14, 1992Date of Patent: November 22, 1994Assignee: Elf Aquitaine ProductionInventors: Didier Etchegoyhen, Henry Henneuse
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Patent number: 5351531Abstract: A depth measuring system for a slickline utilized in a well bore operation where the slickline is in a non-slip relationship with the circumference of a calibrated measuring wheel and the revolutions of the wheel are utilized to provide a first length measurement. A load cell is provided to measure tension in the slickline so that length elongation of the slickline due to tension can be determined. A temperature differential determination is made so that corrections in length can be made for the temperature effects. The temperature differential can be temperature effects on the measuring wheel and/or temperature effects of the slickline in the well bore. The measuring wheel determination of length is algebraically summed with the tension elongation and changes due to temperature to provide a more accurate indication of the depth measurement in the well bore.Type: GrantFiled: May 10, 1993Date of Patent: October 4, 1994Assignee: Kerr Measurement Systems, Inc.Inventor: Wayne L. Kerr
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Patent number: 5291647Abstract: In a combined processing machine provided with a punching press mechanism and a laser head, a detector such as an electric micrometer is mounted on a cross slide provided for moving a workpiece on a work table with the aid of a work piece holder. The detector is made to come into contact with the rear face of the upper turret and subsequently with the laser head and measures the deviation of the punching position and the laser processing position.Type: GrantFiled: April 1, 1993Date of Patent: March 8, 1994Assignee: Murata Kikai Kabushiki KaishaInventors: Chiji Fukasawa, Shunitsu Itou, Hiroshi Kobayashi
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Patent number: 5279043Abstract: 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.Type: GrantFiled: March 20, 1992Date of Patent: January 18, 1994Assignee: RSF-Elektronik Gesellschaft m.b.H.Inventors: Heinz Rieder, Max Schwaiger
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Patent number: 5253430Abstract: 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.Type: GrantFiled: September 26, 1991Date of Patent: October 19, 1993Assignee: RSF-Elektronik Gesellschaft m.b.H.Inventors: Heinz Rieder, Max Schwaiger
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Patent number: 5195826Abstract: The invention is directed to a temperature measuring head for rapidly measuring the temperature of a workpiece on a coordinate measuring apparatus. To rapidly measure the temperature of the workpiece, the coordinate measuring probe element is exchanged for a temperature measuring head which operates pursuant to the principle of a switching probe head. The measuring head supplies a contact signal after contact with the workpiece takes place. From this time point on, the temperature variation is measured by the temperature measuring head and the determined values are stored in the computer of the coordinate measuring apparatus. The temperature of the workpiece is extrapolated via a numerical evaluation method from a specific measurement interval. After the necessary measurement interval, the temperature measuring head is exchanged for the needed probe element combination. The invention is also directed to a temperature measuring head for carrying out the method of the invention.Type: GrantFiled: December 9, 1991Date of Patent: March 23, 1993Assignee: Carl-Zeiss-StiftungInventors: Eckhard Enderle, Michael Wirth, Bernd Baier
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Patent number: 5189807Abstract: A method for determining and, when appropriate, compensating for the linear (heat) expansion of elongated bodies (1), such as physical length scales (1) or of elongated bodies which are intended to support physical length scales on, e.g., instruments or measuring machines equipped with physical length scales, in which measurement errors occur because of length deviations of the scale (1) as a result of deviations from a reference temperature at which the scale was calibrated.The method is mainly characterized by measuring the linear expansion of the body (1) in relation to at least one reference (6) made of a material whose coefficient of linear (heat) expansion (.alpha.) deviates from the coefficient of linear (heat) expansion of the body material, and thereafter determining, when appropriate, a compensation factor for correcting the body length.The invention also relates to an arrangement for carrying out the method.Type: GrantFiled: February 3, 1992Date of Patent: March 2, 1993Assignee: C. E. Johansson ABInventor: Carl-Erik Gustafsson
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Patent number: 5182867Abstract: A position measuring apparatus is described wherein a probing unit is connected with a first object and probes the graduation of a measuring scale which is arranged upon a support member. The support member is fastened to a second object. The support member and the second object have different coefficients of thermal expansion. The support member is rigidly connected with an auxiliary support member. The coefficient of thermal expansion of the auxiliary support member differs from the thermal expansion coefficient of the support member. The cross-sections of the support member and the auxiliary support member are chosen so that the resulting coefficient of thermal expansion of the structural combination of the support member and the auxiliary support member is substantially equal to the coefficient of thermal expansion of the second object.Type: GrantFiled: May 4, 1992Date of Patent: February 2, 1993Assignee: Dr. Johannes Heidenhain GmbHInventor: Gunther Nelle
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Patent number: 5179786Abstract: In measuring apparatus, a workpiece-contacting probe is mounted on a probe-supporting assembly which is maintained at a constant temperature by bathing it with liquid. The liquid is supplied at a constant temperature by a heat exchanger system which also supplies liquid to hydrostatic bearings in the probe-supporting assembly. Before being measured, the workpieces are immersed in a bath which is maintained at a constant temperature. Liquid is fed into the immersion bath by a probe provided with liquid outlets which can be directed against selected areas of a submerged workpiece.Type: GrantFiled: April 22, 1991Date of Patent: January 19, 1993Inventor: Russell S. Shelton
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Patent number: 5142792Abstract: A position measuring device for measuring the relative positions of two objects. A scanning unit for scanning a graduation carrier is mounted on a bed of a processing machine through a coupling which is stiff in measuring direction. The coupling includes a first coupling part in the form of a plate fastened to the scanning unit and a second coupling part in the form of a pin having a spherical end face. The pin is fastened to an engagement member mounted on the bed of the processing machine. A sliding layer is provided between the two coupling parts in order to eliminate wear between the two coupling parts and to eliminate measuring inaccuracies.Type: GrantFiled: May 17, 1991Date of Patent: September 1, 1992Assignee: Dr. Johannes Heidenhaim GmbHInventor: Gunther Nelle
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Patent number: 5095637Abstract: There is provided a measurement embodiment with a resulting thermal expansion which, despite different materials having different thermal expansion coefficients, agrees with the thermal expansion of the machine part so that temperature conditioned measurement inaccuracies are eliminated.Type: GrantFiled: June 6, 1990Date of Patent: March 17, 1992Assignee: Dr. Johannes Heidenhain GmbHInventor: Heinz Kraus
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Patent number: 5095632Abstract: A structure which has a low coefficient of thermal and moisture expansion along one dimension (an axis) is formed of an arrangement of fibers surrounded by and bonded to an engineering thermoplastic resin. The fibers are arranged so that essentially all of the fibers are disposed parallel to the axis. The fibers have a negative coefficient of expansion, the resin has a positive coefficient of expansion, and the volume ratio is balanced so that the composite structure has a near zero coefficient of expansion. Perferably the structure is formed by pultrusion of overlapped tapes of aligned carbon fibers preimpregnated with polyphenylene sulfide. A scale having this structure has slots for indicating position on the scale. The slots extend through the scale and are transverse to the axis.Type: GrantFiled: June 15, 1990Date of Patent: March 17, 1992Assignee: Parker Hannifin CorporationInventors: William L. Hassler, Jr., Stephen F, McCleskey
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Patent number: 5065526Abstract: The invention is directed to an optoelectronic probing device for a coordinate measuring apparatus. The probe is exchangeable automatically via a probe changing device. The probing device has a temperature sensor which is in thermal contact with the material of the probing device. The connecting terminals of the sensor are applied to contacts on the exchange face of the probing device. In this way, it is possible to immediately determine the position of the optoelectronic components of the probe from the calibration data obtained at other temperatures after each probe exchange.Type: GrantFiled: March 18, 1991Date of Patent: November 19, 1991Assignee: Carl-Zeiss-StiftungInventor: Karl-Hermann Breyer
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Patent number: 5065525Abstract: At least one of the surfaces of the glass or glass-ceramic graduated-scale support (12) of a measuring device is drawn toward a corresponding surface of the guide part (11) by the capillary action of a liquid film (13). The graduated-scale support floats without friction on this liquid film and is secured against floating away laterally by low-friction stops (16-18) which can also be formed of the liquid film itself or suitable shaping of graduated-scale support and of the guide part to which it is mounted. The graduated-scale support advantageously consists of a material having a precisely known small coefficient of thermal expansion, such as quartz glass, or of a material having a negligibly small coefficient of expansion, such as the commercially available glass ceramic material known as Zerodur. By these measures, length or other measurement errors attributable to thermal effects are minimized.Type: GrantFiled: September 4, 1990Date of Patent: November 19, 1991Assignee: Carl-Zeiss-Stiftung, Heidenheim/BrenzInventor: Franz Szenger
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Patent number: 5052121Abstract: A computerized gauge measures dimensions, typically in the range of 6.1865" to 6.1917" accurate to .+-.0.001", typically the diameter of a steel railroad car axle. The gauge simultaneously senses the temperature, typically within a range of -20.degree. F. to 100.degree. F.+1.degree. F., of the axle workpiece. In consideration of the predetermined coefficient of expansion of the workpiece, the gauge calculates the dimension that the workpiece would exhibit should it be thermally brought to a predetermined, 59.degree. F. by convention, reference temperature. From the workpiece-temperature-compensated dimension resulting from such calculation, the axle may be recognized as being (i) oversized but repairable, (ii) within an acceptable size range, (iii) undersized but repairable, or (iv) undersized and unrepairable.Type: GrantFiled: July 13, 1990Date of Patent: October 1, 1991Assignee: Albion Devices, Inc.Inventor: William R. Wachtler
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Patent number: 5050311Abstract: A length or angle measuring apparatus which measures the relative position of two objects comprises a scale attached to a first object to be measured and a scanning unit which has at least one scanning element connected to the second object to be measured, wherein the second object and the scanning unit have different thermal expansion coefficients. The graduation of the scale is scanning by a scanning element of the scanning unit at a scanning point. Fastening means are provided which fasten the scanning unit to the second object to be measured, such that the scanning point of the scanning element of the scanning unit has no zero point displacement with temperature changes.Type: GrantFiled: November 14, 1990Date of Patent: September 24, 1991Assignee: Dr. Johannes Heidenhain GmbHInventor: Guenther Nelle
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Patent number: 5038491Abstract: A scale, for measuring the displacement of an object to be examined, has a division and a mark for alignment of the division, and a displacement measuring apparatus, for measuring the displacement of a scale, has a device for reading the division of the scale and a detector for detecting the positional error of the division relative to the direction of the displacement.Type: GrantFiled: June 22, 1989Date of Patent: August 13, 1991Assignee: Canon Kabushiki KaishaInventors: Masaaki Tsukiji, Tetsuharu Nishimura, Satoshi Ishii, Koh Ishizuka
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Patent number: 5031331Abstract: A coordinate measuring apparatus includes guides made of aluminum. Scales which are also made of aluminum are used to measure the position of the measuring slide movable on the guides. In a preferred embodiment, the scales are in the form of a reflection phase grating and are applied directly to the surface of the guide member. In addition, a temperature sensor is provided which measures the temperature of the guide member and of the scale divisions. A method of producing the scale divisions is also disclosed.Type: GrantFiled: December 11, 1989Date of Patent: July 16, 1991Assignee: Carl-Zeiss-StiftungInventors: Klaus Herzog, Karl Seitz, Karl Schepperle, Peter hnelt
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Patent number: 5029194Abstract: Measuring the distance to a surface of an object using ultrasonic energy pulses, an ultrasonic energy pulse is directed toward the object and the time is measured for the reflection to return so as to determine the distance to the object. A reference ultrasonic pulse is directed through a fixed and known distance to provide a reference measurement. To enhance the accuracy of the measurement, the air in the region traversed by the ultrasonic pulses is mixed by directing a swirling flow of air in this region so that the temperature of the air in the path of the reference measurement is more nearly representative of the temperature of the air where the distance measurement is taken.Type: GrantFiled: February 5, 1990Date of Patent: July 2, 1991Assignee: Troxler Electronic Laboratories, Inc.Inventors: James E. Young, Ali Regimand
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Patent number: 5016359Abstract: A scale arrangement is designed for monitoring relative displacement between first and second members. The scale arrangement comprises an elongated scale having end portions at both ends thereof, a pair of receptacles respectively receiving the end portions, a hollow member receiving the scale therein, the hollow member being formed into essentially quadrate cross section, a head slidingly mounted on the scale for axial movement therealong for reading scale to generate a read scale indicative signal, a head slider associated with the head for axial movement with the head, the end portions, the receptacles and the head sliders being positioned on respectively associated one of first and second members with respect to the end portions, position of the head slider being determined with respect to a reference plane set on the outer peripheral plane on the hollow member in relation to the end portion.Type: GrantFiled: May 30, 1989Date of Patent: May 21, 1991Assignee: Sony Magnescale Inc.Inventors: Kazuo Nagaoka, Tadao Hatano, Sadao Wakabayashi, Takamitsu Shimizu
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Patent number: 5014444Abstract: The invention is directed to a probing device for a coordinate measuring apparatus. The probe is exchangeable automatically via a probe changing device. The probing device has a temperature sensor which is in thermal contact with the material of the probing device. The connecting terminals of the sensor are applied to contacts on the exchange face of the probing device. In this way, it is possible to immediately determine the position of the sensing ball of the probe from the calibration data obtained at other temperatures after each probe exchange.Type: GrantFiled: November 3, 1989Date of Patent: May 14, 1991Assignee: Carl-Zeiss-StiftungInventor: Karl-Hermann Breyer
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Patent number: 5011297Abstract: An apparatus for detecting temperature of an object to be measured such as a workpiece mounted on a coordinate measuring apparatus having a movable measuring arm. The measuring apparatus includes a sensing pin or complete sensing head as well as a temperature sensor. For measuring temperature, the sensing pin or sensing head is exchange for the temperature sensor having the same kind of holder as the sensing pin. Thereafter, the temperature sensor is moved to the object by the measuring arm of the apparatus and is placed in contact therewith. The registered temperature measurement values are used to correct the lengths and spacings measured with the coordinate measuring apparatus. The entire temperature and coordinate measuring operation is carried out completely automatically by the CNC control of the apparatus without the aid of operating personnel. A temperature sensor for carrying out the method of the invention is also disclosed.Type: GrantFiled: September 24, 1990Date of Patent: April 30, 1991Assignee: Carl-Zeiss-StiftungInventor: Jakob Tittl
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Patent number: 5009512Abstract: A device and method for measuring the deformations of a sample, which deformations particularly result from the relaxation of the stresses to which the samples was previously subjected. The device and method include the use of a cell inside which the sample is placed with the cell containing a thermal mass whose heat capacity and/or thermal conductibility are appreciably greater than those of air under normal temperature and pressure conditions.Type: GrantFiled: May 9, 1990Date of Patent: April 23, 1991Assignee: Institute Francais du PetroleInventors: Jacques Lessi, Philippe Perreau, Daniel Bary, Guy Grard
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Patent number: 5001842Abstract: Apparatus with a multi-axis mechanism to perform, say, measurements or tests, has at least one pair of temperature detectors individually for each of selected members of the mechanism, each pair of temperature detectors being arranged to sense temperature differences transversely across the associated member. The required positions of the temperature detectors are predetermined from a preliminary examination of the mechanism, so that the extent and direction of each predetermined aspect of thermal distortion within the mechanism, can be computed from simultaneously detected transverse temperature differences, employing algorithms devised as a result of the preliminary examination of the mechanism. Compensation for corresponding selected errors in the measurements or tests can be calculated from the computed extent and direction of each of the predetermined aspects of thermal distortion within the mechanism.Type: GrantFiled: January 10, 1990Date of Patent: March 26, 1991Assignee: Ferranti International plcInventors: David A. Wright, Alexander T. Sutherland
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Patent number: 4997287Abstract: A method for detecting temperature of an object to be measured such as a workpiece mounted on a coordinate measuring apparatus having a movable measuring arm. The measuring apparatus includes a sensing pin or a complete sensing head as well as a temperature sensor. For measuring temperature, the sensing pin or sensing head is exchanged for the temperature sensor having the same kind of holder as the sensing pin. Thereafter, the temperature sensor is moved to the object by the measuring arm of the apparatus and is placed in contact therewith. The registered temperature measurement values are used to correct the lengths and spacings measured with the coordinate measuring apparatus. The entire temperature and coordinate measuring operation is carried out completely automatically by the CNC control of the apparatus without the aid of operating personnel. A temperature sensor for carrying out the method is also disclosed.Type: GrantFiled: June 21, 1989Date of Patent: March 5, 1991Assignee: Lab Products, Inc.Inventor: Jakob Tittl
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Patent number: 4991311Abstract: A magnetic linear scale unit comprises a magnetic scale and mounting blocks which are designed to be rigidly fixed to one of relatively displaceable mechanical components, about which magnitude or stroke of the relative thrusting displacement is to be measured. The magnetic scale has end sections to be mounted on the mounting blocks. The end sections have round peripheral portion mating with the mounting block. At least one of the end section also includes a structural component which allows pivotal movement of the magnetic scale relative to the mounting block for fine adjustment of the axis of the magnetic scale relative to the axis of relative movement of the mechanical components. A scale channel is free from the mounting block and simply serves as the magnetic shield. Therefore, the scale channel of the invention is substantially free from the accuracy requirement and production error of the scale channel and will never affect measurement of the displacement magnitude.Type: GrantFiled: June 26, 1989Date of Patent: February 12, 1991Assignee: Sony CorporationInventors: Kazuo Nagaoka, Sadgo Wakabayashi, Yoshihiko Kanasugi, Tadao Hatano
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Patent number: 4982508Abstract: A position measuring device including a scale carrier member and a scanning device for scanning the scale. A temperature difference is generated between the scale carrier member and/or the scanning device, on the one hand, and a housing surrounding the scale carrier member and the scanning device, on the other hand. The temperature difference ensures that condensate is always precipitated on the colder housing.Type: GrantFiled: June 22, 1989Date of Patent: January 8, 1991Assignee: Dr. Johannes Heidenhain GmbHInventors: Gunther Nelle, Walter Schmitt, Reinhold Schopf, Josef Weiss
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Patent number: 4982507Abstract: 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.Type: GrantFiled: January 22, 1990Date of Patent: January 8, 1991Assignee: RSF-Elektronik Gesellschaft m.b.H.Inventors: Heinz Rieder, Max Schwaiger
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Patent number: 4949469Abstract: A computerized gauge measures dimensions, typically in the range of 6.1865" to 6.1917" accurate to .+-.0.001", typically the diameter of a steel railroad car axle. The gauge simultaneously senses the temperature, typically within a range of -20.degree. F. to 100.degree. F. +1.degree. F., of the axle workpiece. In consideration of the predetermined coefficient of expansion of the workpiece, the gauge calculates the dimension that the workpiece would exhibit should it be thermally brought to a predetermined, 59.degree. F. by convention, reference temperature. From the workpiece-temperature-compensated dimension resulting from such calculation, the axle may be recognized as being (i) oversized but repairable, (ii) within an acceptable size range, (iii) undersized but repairable, or (iv) undersized and unrepairable.Type: GrantFiled: July 1, 1988Date of Patent: August 21, 1990Assignee: Albion Devices, Inc.Inventor: William R. Wachtler
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Patent number: 4912856Abstract: A position measuring device for measuring the relative positions of two objects, wherein the two objects are machine components of a processing or working machine or a measuring machine for tools. The graduation of a scale connected to the first object is scanned by a scanning unit connected to the second object. The scale is arranged on a scale carrier so as to be slightly displaceable in a measuring direction. The scale carrier is connected with both ends thereof to fastening elements which, in turn, are rigidly connected to the first object. When the scale, the scale carrier and the workpiece have different thermal expansion, the scale carrier is connected at least at one end thereof to the fastening element with a translatory degree of freedom in measuring direction. The scale is biased at least at one end thereof by a spring element. The spring element is connected to the translatory movable end of the scale carrier.Type: GrantFiled: June 10, 1988Date of Patent: April 3, 1990Assignee: Dr. Johannes Heidenhain GmbHInventor: Alfons Ernst
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Patent number: 4843729Abstract: A magnetic linear scale unit comprises a magnetic scale and mounting blocks which are designed to be rigidly fixed to one of relatively displaceable mechanical components, about which magnitude or stroke of the relative thrusting displacement is to be measured. The magnetic scale has end sections to be mounted on the mounting blocks. The end sections have round peripheral portion mating with the mounting block. At least one of the end section also includes a structural component which allows pivotal movement of the magnetic scale relative to the mounting block for fine adjustment of the axis of the magnetic scale relative to the axis of relative movement of the mechanical components. A scale channel is free from the mounting block and simply serves as the magnetic shield. Therefore, the scale channel of the invention is substantially free from the accuracy requirement and production error of the scale channel and will never affect measurement of the displacement magnitude.Type: GrantFiled: August 18, 1987Date of Patent: July 4, 1989Assignee: Sony Magnescale, Inc.Inventors: Kazuo Nagaoka, Sadao Wakabayashi, Toshihiko Kanasugi, Tadao Hatano
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Patent number: 4835830Abstract: A method of manufacturing an embodiment of a measure including a bending resistant graduation carrier member and a base member and fastening elements for fastening the graduation member on the base member. The material of the graduation carrier member has a lower temperature coefficient than the material of the base member. The graduation carrier member is placed on the base member in a floating manner. Subsequently, the graduation carrier member and the base member are heated to a predetermined temperature. The end faces of the graduation carrier member are then fixed by means of the fastening elements to the base member in such a way that the graduation carrier member is in a compressed state when cooled to normal temperature.Type: GrantFiled: October 27, 1988Date of Patent: June 6, 1989Assignee: Johannes Heidenhain GmbHInventor: Walter Miller
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Patent number: 4831737Abstract: An apparatus for compensating for the thermal expansion of two machine parts which are relatively movable in longitudinal guideways. The apparatus comprises a rule, a support rod longitudinally disposed on the movable machine part for supporting the rule, and an electric scanning head mounted on the stationary machine part. The support rod is made of a material which exhibits negligible thermal expansion in the concerned temperature range. The forward end of the support rod is rigidly secured to the forward end of the movable machine part while the rear end thereof is movably guided on that machine part. The rear end of the rule is fixed to the rear end of the support rod. The scanning head is disposed on the stationary machine part in such a way that any thermal expansion of the stationary machine part cannot affect the location of the scanning head.Type: GrantFiled: August 4, 1987Date of Patent: May 23, 1989Assignee: MAHO AktiengesellschaftInventor: Peter Grund