Electromotive Or Electromagnetic Force Patents (Class 177/210EM)
  • Patent number: 6129168
    Abstract: An weight sensor (16) for use in the crash management system of a motor vehicle's safety restraint system (10). The weight sensor (16) functions to determine the weight of an occupant sitting on a vehicle seat (12) and is mounted between the seat frame (42) and mounting structure (46) of the vehicle seat (12). The weight sensor (16) includes a position sensing unit (52) retained in an enclosed housing assembly (50). The weight of a seat occupant causes a portion (56) of the housing assembly (50) to deflect and the position sensing unit (52) measures the corresponding displacement caused by such deflection. The position sensing unit (52) includes a Hall effect sensor (70) fixed to the rigid portion (54) of the housing assembly (50) and a magnet (74) fixed to the deflectable portion (56) of the housing assembly (50).
    Type: Grant
    Filed: November 19, 1997
    Date of Patent: October 10, 2000
    Assignee: Breed Automotive Technology, Inc.
    Inventors: James C. Lotito, Matthew W. Owen, Ronald A. Marker, deceased
  • Patent number: 6087598
    Abstract: A weight sensor (10) senses a load applied to a vehicle seat (12). The sensor includes a first mounting member (40; 120) and a second mounting member (42; 122) positioned opposite from and movable relative to the first mounting member (40; 120). A pair of spaced apart and opposed guide elements (44 and 46; 132 and 134) are connected between the first and second mounting members (40 and 42; 120 and 122), respectively. The pair of guide elements (44 and 46; 132 and 134) guide relative movement between the first and second mounting members (40 and 42; 120 and 122). Biasing means (44 and 46; 132 and 134) are provided for urging a spaced apart relationship between the first and second mounting members (40 and 42; 120 and 122).
    Type: Grant
    Filed: February 3, 1999
    Date of Patent: July 11, 2000
    Assignee: TRW Inc.
    Inventor: Carl A. Munch
  • Patent number: 5998742
    Abstract: A force transducer and method of measuring an applied force such as a weight of material, comprising a balance beam, said balance beam being supported at a preset position on a base at a fulcrum between its two ends, a voice coil actuator comprising an electrically conductive coil and a magnet, the coil being mounted on the base and the magnet being mounted on one side of the fulcrum of the balance beam, a counterbalance mounted on the second side of the fulcrum of the balance beam whereby said balance beam is generally unresponsive to low frequency vibration at the base, a beam position sensor for detecting beam movement from its preset position by a force applied to the beam, a control system associated with the sensor and coil and responsive to the sensor for supplying an electric current through the coil in an amount sufficient to maintain the magnet and thereby the beam at the present position, and a current detector for measuring the amount of current so supplied and thereby the amount of the applied fo
    Type: Grant
    Filed: July 2, 1998
    Date of Patent: December 7, 1999
    Assignee: Eveready Battery Company, Inc.
    Inventors: Jyh-Dong Liu, Imre Andrew Pattantyus-Abraham, Lin Yang
  • Patent number: 5962818
    Abstract: In a top scale balance which has a Roberval's chain 10 and a load weight transmitting lever 30 and in which a movable post 13 of the Roberval's chain 10 is connected to a point of force 32 of the lever 30 through an elastic connection fulcrum 51, a horizontal member 12 nearer to the elastic connection fulcrum 51, out of upper and lower horizontal members 11, 12 of the Roberval's chain 10, is greater in rigidity than the other horizontal member 11. Alternately, the upper and lower horizontal members 11, 12 are equal in rigidity and the elastic connection fulcrum 51 is positioned, in the vertical direction, at the center between the upper and lower horizontal members 11, 12. Such an arrangement prevents or reduces the movement of the elastic connection fulcrum 51 in the back-and-forth direction due to an offset placed load. Thus, even though the top scale balance is made in a compact and thin design with the lever ratio increased, the top scale balance is high in precision with a less offset position error.
    Type: Grant
    Filed: October 3, 1995
    Date of Patent: October 5, 1999
    Assignee: Shimadzu Corporation
    Inventors: Akira Komoto, Kunio Shimauchi, Kazuo Nishibayashi, Akihiro Fukai
  • Patent number: 5923000
    Abstract: A shock protection device for a force measuring apparatus, particularly a balance, which includes a material block with a stationary parallelogram side member, a deflectable parallelogram side member serving for receiving the force to be measured, two guide members which are bending-elastic in the plane of the parallelogram and which connect the two parallelogram side members, and at least one lever which is connected through a coupling member to the deflectable parallelogram side member. The shock protection device includes a safety bolt inserted into a bore extending at least partially through the force measuring apparatus, wherein the safety bolt is connected without play to one of the components forming the force measuring apparatus, while the safety bolt has radial play relative to the remaining components through which the bolt extends.
    Type: Grant
    Filed: May 22, 1997
    Date of Patent: July 13, 1999
    Assignee: Mettler-Toledo GmbH
    Inventors: Ernst Tschopp, Hans-Rudolf Burkhard, Ferdinand Schneider
  • Patent number: 5902964
    Abstract: A method for measuring the masses of objects in any gravity environment, including microgravity or zero gravity. An object is placed on or attached to a platform that is movable back and forth along a single axis of motion. An actuator is used to oscillate the platform and is controlled to provide a variable spring force. Instantaneous displacement values are obtained and used to calculate the period of oscillation. Values representing the period, the tare mass of the platform, and the spring constant are then used to calculate the mass of the object. The method may use active damping, and may be varied so that the oscillations are angular rather than linear.
    Type: Grant
    Filed: August 21, 1997
    Date of Patent: May 11, 1999
    Assignee: Southwest Research Institute
    Inventors: Ruell F. Solberg, Jr., H. Stanley Silvus
  • Patent number: 5866854
    Abstract: A calibrating device for a balance including a load receiving unit for loads to be weighed, a load measuring unit and a lever mechanism serving for the force transmission between the load receiving unit and the load measuring unit, wherein the lever mechanism is coupled to the load receiving unit through a coupling area on an input side and to the load measuring unit through a coupling area at an output side, and wherein the lever mechanism further includes an additional coupling area, separate from the coupling areas on the input and output sides, for releasably coupling a calibrating force which is uncoupled during the normal weighing operation.
    Type: Grant
    Filed: January 29, 1997
    Date of Patent: February 2, 1999
    Assignee: Mettler-Toledo AG
    Inventors: Jean-Christophe Emery, Thomas Glattli
  • Patent number: 5856638
    Abstract: Weighing apparatus of the electromagnetic load compensation type includes a thermal conductor for transmitting coil heat from the internal region adjacent the air gap of a permanent magnetic field within which the compensation coil is arranged to a remotely-arranged thermal sensor, thereby to dissipate the coil heat and to modify as a function of internal temperature the compensating current that is supplied to the compensation coil. As a consequence of the dissipation of heat from the air gap, heating of the permanent magnet and its pole member is avoided, thereby, to prevent variation of the intensity of the permanent magnet field.
    Type: Grant
    Filed: April 9, 1997
    Date of Patent: January 5, 1999
    Assignee: Mettler-Toledo GmbH
    Inventors: Hans-Rudolf Burkhard, Qihao Yuan
  • Patent number: 5844174
    Abstract: An electronic balance with a balance scale (3) which is movably connected by a parallel guide consisting of an upper (4) and a lower guide rod (5) in a vertical direction to a system carrier (1) fixed to the housing, with at least two wire strain gauges (15) which are arranged in the vicinity of the ends of a guide rod (4), which ends are on the housing side, and which wire strain gauges measure the horizontal forces in the guide rod (4) which are caused by the torque transferred from the balance scale (3) onto the parallel guide, and with electronics which corrects the weight value emitted from the weighing receiver on the basis of the output signals of the wire strain gauges (15) and from stored comer-load correction factors that at least one of the guide rods (4) is supported on its housing-side end on an intermediate piece (18), that this intermediate piece (18) is connected by at least one approximately vertical thin web (13) and by a horizontal thin web (14) to the system carrier (1) fixed to the housin
    Type: Grant
    Filed: August 14, 1997
    Date of Patent: December 1, 1998
    Assignee: Sartorius AG
    Inventors: Otto Kuhlmann, Christoph Berg
  • Patent number: 5771986
    Abstract: A toploaded balance in accordance with the principle of the electromagnetic compensation of force with a divided upper guide rod (3, 3') and a divided lower guide rod (4, 4') which together as a parallel guide connect a load receiver (2) to a system carrier (1) fixed to the housing, which system carrier (1), load receiver (2) and guide rods (3, 3', 4, 4') form a one-piece base, with a translation lever (5) rotatably mounted by two flexible articulations (7) on the system carrier (1), with a coupling element (12) connected by flexible articulations on the one hand to the load receiver (2) and on the other hand to the short lever arm of the translation lever (5), with a magnet build, as viewed from above, into the free space between the parts of the guide rods (3, 3', 4, 4') and their extensions on the system-carrier side and with a coil fastened on the longer lever arm of the translation lever (5) and extending into the air gap of the magnet, the translation lever (5), the two flexible articulations (7) for mo
    Type: Grant
    Filed: July 18, 1995
    Date of Patent: June 30, 1998
    Assignee: Sartorius AG
    Inventors: Heinz-Gerhard Kohn, Jorg Peter Martens, Michael Laubstein, Carsten Tischer, Winfried Graf, Eduard Bierich
  • Patent number: 5760577
    Abstract: The present invention is a displacement sensor, which is capable of keeping high sensing resolution even if the amount of displacement of the core and the amount of changing the inductance are small. In the displacement sensor of the present invention, a displacing body is capable of displacing according to external force. An LC resonance circuit includes a magnetic coil and a core made of a magnetizable material, which is capable of moving close to and away from the magnetic coil according to the displacement of the displacing body. An oscillator inputs continuous signals having prescribed frequency to the LC resonance circuit. A detecting circuit detects the amount of the displacement of the displacing body on the basis of amplitude of the continuous signals from the LC resonance circuit.
    Type: Grant
    Filed: April 19, 1996
    Date of Patent: June 2, 1998
    Assignee: Techno Excel Kabushiki Kaisha
    Inventor: Yoshihiro Shizuya
  • Patent number: 5641948
    Abstract: A force measuring apparatus includes a parallelogram guide composed of a fixedly supported parallelogram side member, two parallel guide members which are longitudinally stiff and bending-elastic in the plane of the parallelogram, and an additional parallelogram side member for receiving the force to be measured. The additional parallelogram side member is guided so as to be deflectable in parallel on the fixedly supported parallelogram side member by the guide members. A measuring transformer supplies a signal corresponding to the force to be measured. A device for transmitting at least a portion of the force on the measuring transformer to be measured acting on the deflectably guided parallelogram side member is coupled through the coupling member to the deflectable parallelogram side member.
    Type: Grant
    Filed: December 14, 1993
    Date of Patent: June 24, 1997
    Assignee: Mettler-Toledo AG
    Inventor: Hans-Rudolf Burkhard
  • Patent number: 5525762
    Abstract: Disclosed is a balance with a first parallel guide (3, 3') which resiliently connector a load receiver (2) to an area (5, 5') fixed to the housing and which is resiliently deformed under the influence of the weight to be measured, and with a second, softer parallel guide (8) which is connected by its one end to the load receiver (2) and by its other (11) end via a force receiver which is at least approximately without displacement to the area (5, 5') fixed to the housing and which transfers as a result thereof a fraction of the force of the weight onto the force measuring receiver that both parallel guides (3, 3', 8) exhibit at least approximately the same height and the same length and are arranged close to one another laterally. The second parallel guide is advantageously locate between two partial areas (3, 5, and 3', 5') of the first parallel guide.
    Type: Grant
    Filed: January 10, 1995
    Date of Patent: June 11, 1996
    Assignee: Sartorius AG
    Inventors: Gunther Maaz, Matthias Eger, Werner Schulze, Christoph Berg, Michael Muller, Eberhard Lubke
  • Patent number: 5493078
    Abstract: An electronic balance provided with a correcting circuit for canceling a thermal drift in the output of a photoreceiver. The photoreceiver is composed of two photosensitive areas and the shadow of a shutter moving with the beam of the balance is cast on the two photosensitive areas. The outputs of the two photosensitive areas are sent to a first subtracting circuit and an adding circuit. The output of the first subtracting circuit is corrected by the output of the adding circuit to produce signal independent of temperature change and corresponding only to the turn of the beam of the electronic balance.
    Type: Grant
    Filed: March 12, 1993
    Date of Patent: February 20, 1996
    Assignee: Shimadzu Corporation
    Inventor: Mitsumasa Uchiike
  • Patent number: 5419204
    Abstract: A force measuring instrument for determining the strength of an applied force by measuring the strength of an electromagnetic force developed so as to counterbalance the applied force, the instrument including a force coil, a displacement sensor for detecting any displacement occurring on a scale balance, an analog arithmetic unit for performing PD operation of analog detecting signals sent by the displacement sensor, a pulse converter for converting the analog signal into a signal having a frequency depending upon the magnitude of the analog signal, an up/down counter for counting up or down pulse signals from the pulse converter depending upon the polarity of the analog signal, a D/A (digital-to-analog) converter for converting the number of counts by the up/down counter into an analog signal, and wherein the sum of the output of the D/A converter and the output of the analog arithmetic unit is fed back to the force coil, thereby ensuring that the counts by the counter alone are used to determine the measur
    Type: Grant
    Filed: March 25, 1994
    Date of Patent: May 30, 1995
    Assignee: Shimadzu Corporation
    Inventors: Toshiyuki Yamaguchi, Akira Komoto
  • Patent number: 5367128
    Abstract: A novel electromagnetic balance-type weighing apparatus according to the invention includes a weighing pan/balance beam assembly (15) whose balance beam is angularly displaced as a function of the weight of an object of weighing placed on the weighing pan. An electromagnetic coil (9) is provided to generate an electromagnetic force that offsets the displacement of the balance beam of the weighing pan/balance beam assembly (15) caused by the weight of the object of weighing. A displacement detector (3, 4, 5) is provided to detect the displacement of the balance beam of the weighing pan/balance beam assembly (15). An operation unit (7) performs operations to determine a control voltage in response to the detection signal transmitted from the displacement detector (3, 4, 5). A current transducer circuit (20) generates an electric current in response to the control voltage applied to it by the operation unit (7) and supplies it to the electromagnetic coil (9).
    Type: Grant
    Filed: May 8, 1991
    Date of Patent: November 22, 1994
    Assignee: Anritsu Corporation
    Inventors: Fumihiro Tsukasa, Hideya Fujimoto, Kazuhiko Horikoshi, Osamu Tanaka, Kunio Kikuchi
  • Patent number: 5340951
    Abstract: Single-piece force-reducing devices for force-measuring apparatuses include levers (18, 25) for reducing the force, and coupling members (17, 21) for transmitting the force, which are formed by no-material portions in one single solid block (1). However, deflection of the levers (18, 25) and, in particular, displacement of their fulcrums (14, 26) leads to incorrect measuring results, so that it is an objective to achieve a very high rigidity of the system under load. In order to achieve such very high rigidity, while the overall size of the system is kept small, the invention provides no-material portions (4, 5, 19, etc.) which make it possible to remove only a minimum of material, resulting in a favorable increase in thickness of the highest-loaded parts, (FIG. 1 ).
    Type: Grant
    Filed: June 15, 1992
    Date of Patent: August 23, 1994
    Assignee: Mettler-Toledo AG
    Inventors: Ernst Hungerbuhler, Hans R. Burkhard
  • Patent number: 5270497
    Abstract: An electric balance which allows a pulse current to flow through a force coil with pulses having two kinds of duties for each period of control time, and generates an electromagnetic force at the ratio of mixture of these pulses wherein the duties are controlled so as to bring the electromagnetic force into equilibrium with a load weight, thereby enhancing the resolution of pulse current duty and achieving the production of a high-resolution electronic balance at a reduced cost.
    Type: Grant
    Filed: March 20, 1992
    Date of Patent: December 14, 1993
    Assignee: Shimadzu Corporation
    Inventor: Akira Komoto
  • Patent number: 5243146
    Abstract: A load weighing apparatus for weighing a weight of a load on a vehicle comprises an intervening element provided between a body frame and a suspension for transmitting the weight of the load to the suspension from the body frame. The intervening element is formed of a magnetic material and has a plurality of bore sections. An excitation winding is wound about the intervening element through ones of the bore sections, while a measurement winding is wound about the intervening element through the remaining bore sections. An electric power source for applying voltage is connected to the excitation winding. A measuring unit for measuring voltage across the measurement winding is connected thereto.
    Type: Grant
    Filed: January 28, 1992
    Date of Patent: September 7, 1993
    Assignee: Yazaki Corporation
    Inventor: Katsuo Nishitani
  • Patent number: 5207285
    Abstract: A method and an apparatus for accurately weighing by a ladle weighing unit (2) of a metal melt in a ladle (3), in which the melt can be heated and stirred by power supplied by an induction coil (4). The induction field of the coil (4) is also applied to a coil weighing unit (1) so that the reaction force of the magnetic field influencing the melt is measured. In a weighing system (5), the net weight of melt is calculated by subtracting the signal of the coil weighing unit (1) from that of the ladle weighing unit (2). The weight change per time unit, which represents the mass flow rate of melt from the ladle, is calculated in the control system (6) and is used to control the pressure in the ladle in such a way the metal flow is kept constant.
    Type: Grant
    Filed: June 3, 1991
    Date of Patent: May 4, 1993
    Assignee: Sandvik AB
    Inventor: Kenneth Josefsson
  • Patent number: 5187442
    Abstract: Method and apparatus of charge distribution analysis insulating and semiconducting dielectric materials to measure by using a Coulomb Balance surface/subsurface space charge layers and the sign, mobility and polarizability of charge carriers. The technique includes measuring the force, attractive or repellent, between a bias electrode to which a voltage is applied and a dielectric material in a condensor half cell arrangement. An apparatus is provided for heating a sample for causing the generation of surface/subsurface charges, and then for applying an external potential while the sample is maintained at a high temperature. The effective mass of the sample is detected by determining the amount of force necessary to restore a balance arm, by which the sample is supported, to its original position, the alteration in position being due to attractive or repulsive electrostatic forces between the sample and the electrodes.
    Type: Grant
    Filed: September 30, 1991
    Date of Patent: February 16, 1993
    Inventors: Friedemann Freund, Francois Batllo, Minoru M. Freund
  • Patent number: 5184690
    Abstract: In a PID-controlled electronic balance consisting essentially of a weighing pan, a pan stopper for defining the lowest position of the weighing pan, a displacement detector for detecting the displacement of the weighing pan, a PID operation circuit and an electromagnetic force transducer, the PID operation circuit is devised so as to operate, when the weighing pan has its movement kept restricted by the pan stopper, with at least one of the mathematical coefficients increased, the coefficients respectively multiplying the proportionality term integral term and differential term contained in the mathematical operation process carried out by the PID operation circuit.
    Type: Grant
    Filed: February 27, 1991
    Date of Patent: February 9, 1993
    Assignee: Shimadzu Corporation
    Inventor: Akira Komoto
  • Patent number: 5000274
    Abstract: A low profile weight sensor for a weight sensing system for monitoring article input and removal from article storage apparatus comprises a plate or I-shaped bar support member having first and second sections, an integrally formed linkage system for connecting the first and second sections such that the sections are substantially coplanar in an unloaded state, and are relatively displaceable with respect to each other in response to a weight load applied to one of the sections; and a magnetic transducer mounted on surfaces extending in the thickness direction of the plate/bar member for producing an electrical output signal responsive to relative displacement of the first and second sections.
    Type: Grant
    Filed: January 18, 1990
    Date of Patent: March 19, 1991
    Assignee: K-Tron International, Inc.
    Inventor: Kenneth W. Bullivant
  • Patent number: 4890246
    Abstract: In high-resolution electric balances a certain residual temperature coefficient remains even with a good correction of the temperature-dependent errors of the measured value sensor. The invention therefore is with respect to a balance with a built-in calibrating weight (standard) which responds with a new calibration switching in said calibrating weight if a given temperature changes has been exceeded since the last calibration. To this end, the balance comprises in microprocessor digital signal processing unit a separate memory area in which the output signal representing temperature value of a temperature sensor is stored during the calibrating process and also comprises a comparator which upon instruction compares the instantaneous output signal of the temperature sensor which the value stored in this separate memory area. If this difference exceeds a given amount, a signal element indicative of need to recalibrate using the calibrating weight is actuated.
    Type: Grant
    Filed: November 19, 1987
    Date of Patent: December 26, 1989
    Assignee: Sartorius GmbH
    Inventors: Christian Oldendorf, Christoph Berg, Franz-Josef Melcher
  • Patent number: 4884031
    Abstract: Method and apparatus of charge distribution analysis insulating and semiconducting dielectric materials to measure by means of a Coulomb Balance surafce/subsurface space charge layers and the sign, mobility and polarizability of charge carriers. The technique includes measuring the force, attractive or repellent, between a bias electrode to which a voltage is applied and a dielectric material in a condensor half cell arrangement. An apparatus is provided for heating a sample for causing the generation of surface/subsurface charges, and then for applying an external potential while the sample is maintained at a high temperature. The effective mass of the sample is detected by determining the amount of force necessary to restore a balance arm, by which the sample is supported, to its original position, the alteration in position being due to attractive or repulsive electrostatic forces between the sample and the electrodes.
    Type: Grant
    Filed: September 29, 1988
    Date of Patent: November 28, 1989
    Inventors: Friedemann Freund, Francois Batllo
  • Patent number: 4765421
    Abstract: A scale is designed to be lightweight and easily portable. The scale comprises two weighing assemblies connected by a flexible joint so that the two assemblies may be folded against each other to form a compact case. Each weighing assembly comprises a weighing platform connected by resilient support members to a based. Weight measurement is effected by a Hall effect sensor in each weighing assembly which measures the variation in magnetic flux density caused by the movement of magnets mounted on the platforms when a load is placed on the platforms. Output from the Hall effect sensors is summed and the total weight is displayed on a digital display.
    Type: Grant
    Filed: June 11, 1987
    Date of Patent: August 23, 1988
    Inventors: Robert F. Newton, Frank D. Sundermeyer
  • Patent number: 4738325
    Abstract: A weight transducer including an extruded housing having upper and lower inner surfaces. Affixed to the upper inner surface is a hall effect magnetic field sensor, and affixed to the lower inner surface is a pair of magnetic field generating magnets. The magnets are arranged with magnetic poles of opposite polarity located adjacent one another. The hall effect sensor senses changes in the magnetic field generated by the pair of magnets due to relative movement between the upper and lower inner surfaces with application of weight to the housing. The voltage output of the hall effect sensor is converted to a signal having a frequency which varies in proportion to the weight applied to the housing. The hall effect weight transducer provides a very rugged and relatively inexpensive yet highly accurate weight transducer.
    Type: Grant
    Filed: December 23, 1986
    Date of Patent: April 19, 1988
    Assignee: K-Tron International, Inc.
    Inventors: Kenneth W. Bullivant, Johannes Wirth
  • Patent number: 4722409
    Abstract: A compact weighing apparatus of the electromagnetic load compensation type is disclosed including a permanent magnet system having a U-shaped soft iron yoke, and a pair of highly coercive permanent magnets of parallelepiped configuration mounted in opposed relation between the adjacent surfaces of the leg portions of the yoke. The compensation coil is mounted for movement between, and in a direction parallel with, the yoke leg portions, the coil having a rectangular cross sectional configuration to define longer coil turn sides arranged adjacent the magnets, respectively. The lever that connects the compensation coil with the load receiving member contains a stepped recess that receives at least a portion of one of the load receiver guide means, thereby to achieve further compactness of the components of the weighing apparatus.
    Type: Grant
    Filed: May 18, 1987
    Date of Patent: February 2, 1988
    Inventor: Peter Kunz
  • Patent number: 4699228
    Abstract: A new mass transducer with electromagnetic compensation is described, comprising a load-detection part, fitted with a coil fixed to the load levers, a reference part comprising a sample weight and a second coil (called reference coil) fixed to the reference levers, a magnetic unit (yoke) with permanent magnets in the air gap whereof the coils are placed coaxially, free to move independently of one another, a control device for keeping the load coil and the reference coil in place and a device for comparing the current flowing through the coils. According to the invention, the coils are of the flattened toric type, their biggest dimension being perpendicular to the longitudinal axis of the lever arm of the load levers and the winding axis X--X of the coil lined up with the force axis.
    Type: Grant
    Filed: June 25, 1986
    Date of Patent: October 13, 1987
    Assignees: Dataprocess S.p.A., Italora S.p.A.
    Inventors: Piercarlo Mustarelli, Franco Lupoli, Emilio Negri
  • Patent number: 4678048
    Abstract: The invention relates to an apparatus for the contactless coupling of a suspended part 9, provided with a magnet 12 and located in a housing 6 to a force measuring device outside housing 6 and which is provided with a controllable electromagnet 1. Unlike in known apparatuses of this type, the position change of the suspended part 9 is recorded in absolute terms with respect to housing 6 and used for controlling electromagnet 1. This gives greater freedom in the design of housing 6, which can now be designed for a wider temperature and pressure range than hitherto, because no longer is it necessary to take account of a distance measurement through the housing wall.
    Type: Grant
    Filed: July 30, 1985
    Date of Patent: July 7, 1987
    Inventors: Hans-Wilhelm Losch, Rainer Kleinrahm, Norbert Pieperbeck, Wolfgang Wagner
  • Patent number: 4625818
    Abstract: The invention suggests an intermittent mode of operation to reduce the stray power in the coil in a balance based on the principle of the electromagnetic compensation of force. To this end, switching means (21) are provided which can interrupt the current flow through the coil (11) so that when the current flow is interrupted, the movable parts (2-9) of the balance move against one of the stops (24) or (25). These switching means (21) are controlled by the digital signal processing unit (18). In addition storage means (20) are provided within the framework of the digital signal processing unit which store the last-determined weight value for the duration of the interruption of the current flow through the coil.
    Type: Grant
    Filed: March 18, 1985
    Date of Patent: December 2, 1986
    Assignee: Sartorius GmbH
    Inventors: Erich Knothe, Franz-Josef Melcher, Christoph Berg
  • Patent number: 4609059
    Abstract: A weighing device having an endless track to which balances are connected, the track having a region for loading the balances with objects, and a region for letting the movement of the balances during weighing of the objects dampen out so that the balances reach an end position. A position detector disposed at a fixed location along the track detects the end position of the balance and provides an indication of the end position in digital form so that the weight of the objects can be determined therefrom. The detector can take a number of forms including the combination of an optical contrast and a camera and, in addition, can, for example, utilize reed switches, Hall generators, Weigand effect detectors or magnetostrictive detectors in measuring the end positions of the balances.
    Type: Grant
    Filed: October 17, 1985
    Date of Patent: September 2, 1986
    Assignee: Administratie - en Automatisergscentrum Vulcaan B.V.
    Inventor: Klaas Pasterkamp
  • Patent number: 4597459
    Abstract: A weight detecting type sensor comprising a roller capable of partly jutting out upwardly from the surface of a body conveying belt, a strut rotatably supporting the roller and having a through-aperture at a portion thereof, a sensor having an optical axis associated with the through-aperture formed in the strut, and a pair of magnets disposed below the bottom of the strut.
    Type: Grant
    Filed: November 28, 1984
    Date of Patent: July 1, 1986
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yoshiki Iwata, Nobuo Kawase, Yoshinori Tanaka, Takashi Miyake, Hiroshi Kawaura
  • Patent number: 4549623
    Abstract: An automatic monitoring system for the constant current source in a balance having electromagnetic load compensation includes circuitry which generates a first current varying in dependence on the constant current and furnishes a digital signal indicative of the value of that current. A microcomputer is provided to compare the digital value to a reference value. If the comparison indicates that the constant current is outside of a given range of values, the microcomputer energizes the display to indicate the presence of an error.
    Type: Grant
    Filed: August 13, 1984
    Date of Patent: October 29, 1985
    Assignee: Mettler Instrumente AG
    Inventor: Arthur Baumann
  • Patent number: 4545448
    Abstract: Weighing apparatus of the electromagnetic load compensation return-to-zero type including a vertically displaceable load support member to which is connected a load compensation coil arranged for movement in a stationary magnetic field, characterized in that the magnetic field is produced by at least one permanent magnet mounted in a hollow yoke structure defined by a pair of U-shaped yoke members each formed of a ferromagnetic material. The yoke members are arranged in opposed coaxial relation with their leg portions being parallel and extending toward each other. The yoke members are relatively angularly displaced about their common axis through an angle of 90.degree., the leg portions of one yoke member extending between the leg portions of the other member.
    Type: Grant
    Filed: August 24, 1984
    Date of Patent: October 8, 1985
    Assignee: Mettler Instrumente AG
    Inventor: Peter Kunz
  • Patent number: 4512429
    Abstract: An electromechanical weighing apparatus is disclosed including a device for correcting the load measurement in accordance with the given gravitational force existing at the geographical place of installation of the weighing apparatus. An adjusting mechanism (6) is used to set various switching states corresponding with given different predetermined gravitational acceleration values, respectively, and a calculator or microprocessor (41)--operable in accordance with the aforementioned switching positions to supply from a storage unit corresponding retrievable gravity values--determines the adjusted gravitational acceleration value that is to be used to modify the measured weight signal to produce a geographically-corrected signal of the mass of the object being weighed that is displayed on the indicating device.
    Type: Grant
    Filed: January 19, 1984
    Date of Patent: April 23, 1985
    Assignee: Mettler Instruments AG
    Inventor: Linus Meier
  • Patent number: 4505344
    Abstract: A multi-axle load vehicle has a tractor, a device supporting a load on the tractor and including an axially displaceable holder arranged on the tractor, a supporting plate arranged to support a load, and at least one pin supporting the supporting plate on the holder, and a device for determining a load acting upon the vehicle and including a sensor arranged in the pin composed of a magnetic material and operative for measuring a load and generating an electric signal corresponding thereto, and an indicating element arranged in a driver's cabin and operative for receiving the electrical signal and indicating the load.
    Type: Grant
    Filed: September 27, 1982
    Date of Patent: March 19, 1985
    Assignee: Robert Bosch GmbH
    Inventors: John Hobbs, Wolfgang Schrader
  • Patent number: 4503922
    Abstract: An electronic bathroom scale employs a low profile planar coil position sensor which responds to the positioning of a pivotable lever system. The levers are coupled to a platform which moves in the vertical direction as a weight is placed upon the top or supporting platform of the scale. The sensor provides variable amplitude or frequency proportional to the weight on the scale. The output signal is processed so that a direct reading of the weight is displayed by means of a digital display. The circuitry described serves to compensate for the nonlinearity of the transducer while further providing other compensation to eliminate environmental effects such as temperature and other factors from affecting the direct display of weight.
    Type: Grant
    Filed: May 26, 1983
    Date of Patent: March 12, 1985
    Assignee: Bitronics, Inc.
    Inventors: Amnon Brosh, David Fiori, Jr.
  • Patent number: 4503923
    Abstract: In an electromagnetic balance based on the principle of the eletromagnetic compensation of force a weight-proportional counterforce is generated by a current-carrying coil in a permanent magnet system. An arrangement with annular coil with vertical axis and with a permanent magnetic system constructed symmetrically to the central plane of the coil has proven to be advantageous. However, this arrangement results in a relatively great construction height of the balance. In order to decrease this height, the invention suggests that the soft iron pole plate which is usually present between the like poles of the plates of active magnetic material be reduced in its diameter or entirely eliminated and that the coil be allowed to extend into this area between the plates of active magnetic material. This in conjunction with the use of materials having high coercivity makes a very low constructional height possible.
    Type: Grant
    Filed: March 11, 1983
    Date of Patent: March 12, 1985
    Assignee: Sartorius GmbH
    Inventor: Gunther Maaz
  • Patent number: 4494022
    Abstract: An electromagnetic force-transducer comprising a magnetic circuit and an electromagnetic coil kept movable in the static field provided by said magnetic circuit. The electromagnetic coil consists of two coaxial parallel windings wound on a common frame with a distance kept between the both. The magnetic circuit comprises an inner magnetic path and an outer magnetic path with a cylindrical clearance left therebetween. In the upper and the lower part of the clearance there are provided with an upper magnetic gap and a lower magnetic gap, respectively. The magnetic field in the upper gap and that in the lower gap are directed oppositely to each other. The coil frame is kept movable vertically in the cylindrical clearance, positioning one of the two windings in the upper magnetic gap and the other in the lower magnetic gap. The two windings are current-supplied in the directions opposite to each other to produce their respective electromagnetic forces in the same direction.
    Type: Grant
    Filed: March 23, 1984
    Date of Patent: January 15, 1985
    Assignee: Shimadzu Corporation
    Inventors: Toshio Kawara, Yoshihumi Shibahara
  • Patent number: 4489800
    Abstract: Electromagnetic load compensation weighing apparatus including a temperature correction circuit having a temperature-responsive element mounted in heat sensing relation relative to the permanent magnet, characterized by the further mounting of a component of the compensating current supply circuit in heat-responsive relation relative to the permanent magnet. A Zener diode serving as a reference voltage device in the compensating current supply circuit is preferably the component that is mounted, together with the temperature-responsive element, in heat conducting relation in a common bore contained within the permanent magnet.
    Type: Grant
    Filed: July 27, 1983
    Date of Patent: December 25, 1984
    Assignee: Mettler Instrumente AG
    Inventors: Bruno Nufer, Paul Luchinger
  • Patent number: 4487279
    Abstract: An electronic balance whose force equilibrating unit consists of a coarse balancing system and a fine balancing system to obtain a precise value of weight measurement in a short time.
    Type: Grant
    Filed: August 19, 1982
    Date of Patent: December 11, 1984
    Assignee: Shimadzu Corporation
    Inventor: Akira Komoto
  • Patent number: 4487276
    Abstract: The scale is of limited height and utilizes Z-shaped flexures between the load frame and support frame. The scale can be placed in a hospital bed for weighing bed-ridden patients or for monitoring weight variations in bed-ridden patients.A cart is provided for transporting the scale from place to place and includes an inclined ramp from which the scale may be readily moved onto a bed.
    Type: Grant
    Filed: May 3, 1983
    Date of Patent: December 11, 1984
    Inventors: Burt L. Swersey, Peter I. Fried
  • Patent number: 4487280
    Abstract: A correction of temperature errors of the measured value receiver is generally necessary in high-resolution electronic balances. This can be accomplished in a known manner by directly influencing the measured value receiver with the aid of an analogous temperature sensor or by digitizing the output signal of the temperature sensor in a digitizer on the output side and performing the correction in the digital signal processing part. The invention has the task of indicating a circuit which permits the high-resolution digitizer which is present in the balance in any case to be used for digitizing the temperature signal without diminishing its preciseness. A switch (25 in FIG. 1) is provided to this end which feeds the output signal of a temperature sensor (27) to the input of the digitizer (15) in addition to the signal of the measured value receiver (1 . . . 13) at certain times controlled by the digital signal processing unit (22).
    Type: Grant
    Filed: March 31, 1983
    Date of Patent: December 11, 1984
    Assignee: Sartorius GmbH
    Inventors: Erich Knothe, Franz-Josef Melcher, Christian Oldendorf, J/u/ rgen Ober
  • Patent number: 4457386
    Abstract: A weighing system of the electromagnetic load compensation type is disclosed including a counter for counting the weight-responsive pulses which are produced during the periods that the compensating current is supplied to the movable coil to return the movable scale member toward its initial no-load position, characterized by the provision of a temperature-responsive device for supplying to the counter a train of temperature-correction pulses that are used to modify the count of the weight-responsive pulses, whereby a more accurate indication of the applied load is obtained. Thus, an analog signal from the temperature sensor is compared with a sawtooth signal to produce a digitalized temperature-responsive signal which modifies the digital weight signal supplied to the microprocessor circuit.
    Type: Grant
    Filed: September 23, 1982
    Date of Patent: July 3, 1984
    Assignee: Mettler Instruments AG
    Inventors: Oskar Schett, Richard Leemann
  • Patent number: 4450923
    Abstract: It is known in high-resolution electronic weighing scales based on the principle of electromagnetic force compensation that the load-dependent development of heat in the coil and the precision resistor can be compensated by sending an additional alternating current through the coil and the precision resistor which is complementarily regulated in its amplitude. In order to make possible a precise regulation of the amplitude of the additional alternating current even in the case of a small carrying force of the electromagnetic force compensation and of a correspondingly small direct compensating current, the invention proposes connecting in a voltage divider in parallel to the coil and the precision resistor which has a highly temperature-dependent resistor. In this parallel branch direct and alternating current are higher by a constant proportionality factor than in the main branch formed by coil and precision resistor.
    Type: Grant
    Filed: December 17, 1982
    Date of Patent: May 29, 1984
    Assignee: Sartorius GmbH
    Inventors: Lothar Behrend, Erich Knothe, Franz-Josef Melcher, Jurgen Ober
  • Patent number: 4450924
    Abstract: It is known in high-resolution electronic weighing scales based on the principle of electromagnetic force compensation that the load-dependent development of heat in a coil and a precision resistor can be compensated by sending an additional alternating current through the coil and the precision resistor which is complementarily regulated in its amplitude. In order to regulate the amplitude of this alternating current, the invention proposes a simplified circuit which comprises a highly temperature-dependent resistor, the resistance value of which is set at a fixed theoretical value.
    Type: Grant
    Filed: December 17, 1982
    Date of Patent: May 29, 1984
    Assignee: Sartorius GmbH
    Inventors: Lothar Behrend, Eric Knothe, Franz-Josef Melcher, Jurgen Ober
  • Patent number: 4438823
    Abstract: A load cell is disclosed which in its full operating range entirely eliminates the effects of off-center loading and lends itself to simplicity and economy in manufacturing. The core element of a linear variable differential transformer employed to measure spring deflection is adjustable with precision on two orthogonal axes. Two circular cross section cantilever arms or springs which carry the movable load-receiving member are anchored to a fixed support member in a common vertical plane through the center axis of the linear variable differential transformer and through the support for the core of such transformer which is connected to the movable load-receiving member. State of the art precision weight range indicating means is utilized.
    Type: Grant
    Filed: August 9, 1982
    Date of Patent: March 27, 1984
    Assignee: DBI Industries, Inc.
    Inventors: Bernard H. Hussels, Charles T. Goetz
  • Patent number: 4429757
    Abstract: A weighing apparatus of the electromagnetic load compensation type is disclosed, including a housing, a load receiver connected for vertical movement relative to the housing, a permanent magnet system connected with the housing for establishing a permanent magnetic field, and an electromagnetic compensating system including a compensation coil connected with the load receiver for movement within the magnetic field. The invention is characterized in that--in order to simplify manufacture and assembly while also achieving low structural height-the permanent magnet system includes a hollow sectional open-ended soft iron yoke member having a generally rectangular cross-sectional configuration, which yoke member is formed from a pair of longitudinally extending generally identical sections. At least one flat permanent magnet is mounted on the inner surface of the yoke member for establishing a flux path therein to generate the magnetic field.
    Type: Grant
    Filed: March 23, 1982
    Date of Patent: February 7, 1984
    Assignee: Mettler Instrumente AG
    Inventor: Peter Kunz
  • Patent number: 4382480
    Abstract: A weighing machine employing electromagnetic forces having a weighing pan which is mounted at the top portion thereof. An electromagnetic coil is employed in an air gap of a stationary permanent magnet system for generating a compensating force. The coil has a rectangular shape while the permanent magnet system consists of rectangular plates of magnetically active material with the vertical direction of magnetism being above or below the longer sides of the coil. A horizontal compensating force results.
    Type: Grant
    Filed: July 13, 1981
    Date of Patent: May 10, 1983
    Assignee: Sartorius GmbH
    Inventors: Erich Knothe, Christoph Berg, Franz-Josef Melcher