Patents Assigned to Flowtec AG
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Patent number: 5616868Abstract: To achieve high measurement accuracy of Coriolis-type single-tube hoop-mode mass flow sensors for nonideal fluids, such a mass flow sensor comprises a vibrating system containing a single straight measuring tube as a main vibrator and an auxiliary vibrator which does not come in contact with the fluid and is mechanically coupled to the measuring tube via connecting elements, the vibrating system being so excited in a natural frequency of vibration by means of at least one exciter that the measuring tube vibrates in a hoop mode. The mass flow sensor further comprises a support tube, to which the vibrating system is attached at the ends and via which the vibrating system is connected with a conduit, and sensors for the inlet-side and outlet-side vibrations of the measuring tube. The vibrating system is so designed that its kinetic energy is at least twice as high as that of the measuring tube.Type: GrantFiled: May 7, 1996Date of Patent: April 1, 1997Assignee: Endress & Hauser Flowtec AGInventors: Heinrich Hagenmeyer, Alfred Wenger
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Patent number: 5610342Abstract: This method of fixing the ends of measuring tubes in associated transition pieces of a Coriolis-type mass flow sensor eliminates the risk of stress-corrosion cracking in these areas as completely as possible. The ends of the measuring tubes are inserted into associated bores of the respective transition pieces and are press-bonded to the walls of the respective bores without heat supply using a rolling tool which is inserted into the respective ends.Type: GrantFiled: May 3, 1995Date of Patent: March 11, 1997Assignee: Endress + Hauser Flowtec AGInventors: Alfred Wenger, Gerhard Eckert, Rainer Lorenz
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Patent number: 5602345Abstract: This mass flow sensor, which can be installed in a fluid-carrying conduit of a given diameter so as to be axially aligned with the conduit, and whose production costs are drastically reduced, has an inlet tube and an outlet tube which serve to connect the mass flow sensor with the conduit, an inlet manifold and an outlet manifold, an external support tube whose end portions are fixed with their inside surfaces to the inlet manifold and outlet manifold, respectively, and with their faces to the inlet tube and outlet tube, respectively, two parallel, straight measuring tubes of the same inside diameter and the same wall thickness each having its two end portions fixed in parallel bores of the inlet manifold in alignment with the inlet tube and in parallel bores of the outlet manifold in alignment with the outlet tube, respectively, two node plates interconnecting the two measuring tubes near the inlet manifold and the outlet manifold, respectively, two vibration exciters, one per measuring tube, which excite thType: GrantFiled: May 3, 1995Date of Patent: February 11, 1997Assignee: Endress + Hauser Flowtec AGInventors: Alfred Wenger, Gerhard Eckert, Rainer Lorenz, Ennio Bitto, Patrick Fleury, Ole Koudal
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Patent number: 5569859Abstract: To create vortex flow sensors with an extended range of constant Strouhal number toward small Reynolds numbers, with a small variation of the vortex separation frequency, and with precise calculability of the Strouhal number in the range of a constant volumetric-flow-rate/vortex-separation-frequency ratio, a drag body is provided which is permanently connected with the internal wall of a fluid-conducting measuring tube of inside diameter D, or fixed in a frame set in the measuring tube, at diametrically opposed points, and which consists of an upstream-side flat trapezoidal part of length l.sub.1, of base width b.sub.1 on the upstream side, and of base width b.sub.2 on the downstream side, and a wake part adjoining the trapezoidal part without a gap and having a cross section in the form of a triangle of length l.sub.2 and base width b.sub.3. The following dimensioning equations hold:0.1.ltoreq.b.sub.1 /D.ltoreq.0.35;0.6.ltoreq.b.sub.2 /b.sub.1 .ltoreq.0.95;0.1.ltoreq.1.sub.1 /b.sub.1 .ltoreq.0.2;0.75.ltoreq.Type: GrantFiled: December 22, 1994Date of Patent: October 29, 1996Assignee: Endress & Hauser Flowtec AGInventors: Heinz Gatzmanga, Andreas Breier
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Patent number: 5557973Abstract: A mass flow sensor is provided to be installed in a conduit through which a fluid flows. The mass flow sensor includes flanges for mounting to the conduit, a single measuring tube, an external support tube, and an internal support element. The measuring tube is fixed at its ends to the flanges and includes a vibrating portion having the shape of a circular constant-pitch helix. The external support tube includes external support tube ends fixed to the measuring tube or flanges. The internal support element includes internal support element ends fixed to the measuring tube adjacent to the flanges.Type: GrantFiled: September 9, 1994Date of Patent: September 24, 1996Assignee: Endress + Hauser Flowtec AGInventors: Ole Koudal, Alfred Wenger
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Patent number: 5540103Abstract: To minimize the material consumption for coils, their pole pieces, and the magnetic return path in electromagnetic flow sensors with reduced overall length and nominal diameters between 200 mm and 700 mm, a measuring tube is provided through which flows an electrically conductive fluid to be measured, and which has at least two measuring electrodes. At the measuring tube, means are provided for generating a magnetic field passing through the measuring tube which comprise: coils, coil cores, and pole stampings which are disposed diametrically opposite to each other on the outside surface of the measuring tube and extend on both sides of the respective coil in the circumferential direction, with their ends separated by a sufficient distance, and two magnetic return-path stampings each disposed on the outside surface of the measuring tube on one side of the coils and the pole stampings and completely surrounding the measuring tube and magnetically coupled via the coil cores to the pole stampings.Type: GrantFiled: September 30, 1994Date of Patent: July 30, 1996Assignee: Endress+Hauser Flowtec AGInventor: Thomas Zingg
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Patent number: 5533408Abstract: To permit this flowmeter to automatically operate either on one measurement principle or on another depending on a selectable foreign-particle content of the fluid, it has a first pair of ultrasonic transducers, one of which is operated as a transmitting transducer and the other as a receiving transducer or vice versa, and which are mounted on the outside surface of a fluid-carrying pipe and separated by a given distance in a direction parallel to the axis of the pipe, with the angle between the direction of the ultrasound and the pipe axis differing from 90.degree.. There is provided a second pair of ultrasonic transducers which are operated simultaneously as transmitting transducers or receiving transducers and are mounted on the outside surface of the pipe and separated by a given distance in a direction parallel to the axis of the pipe, the angle between the direction of the ultrasound and the pipe axis being less than or equal to 90.degree..Type: GrantFiled: December 22, 1994Date of Patent: July 9, 1996Assignee: Endress + Hauser Flowtec AGInventors: Daniel Oldenziel, Marcel Griessmann
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Patent number: 5531126Abstract: This mass flow sensor is to be fitted with two straight tubes, but conventionally needed manifolds are to be dispensed with. The sensor can be installed, by flanges, in a conduit of a given diameter so as to be axially aligned with the conduit, through which flows a fluid to be measured. It has a straight measuring tube, which extends between the flanges and is traversed by the fluid, and a straight dummy tube, which extends parallel to the measuring tube and is not traversed by the fluid. Also provided are a nodal plate on the inlet side and a nodal plate on the outlet side, one of which fixes the inlet-side end portion of the measuring tube to the corresponding end portion of the dummy tube, and the other of which fixes the outlet-side end portion of the measuring tube to the corresponding end portion of the dummy tube, such that the measuring tube and the dummy tube are arranged side by side. A support tube has its ends fixed to the respective flanges.Type: GrantFiled: July 19, 1994Date of Patent: July 2, 1996Assignee: Endress + Hauser Flowtec AGInventor: Wolfgang Drahm
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Patent number: 5479007Abstract: This optoelectronic, finger-operated keyboard for use in industrial measurement equipment is designed to achieve an optimum signal-to-noise ratio and minimize the drop in the intensity of the infrared emitters during the service life of the measurement equipment. The keys for generating respective associated operation signals (n1, n2, n3) have an infrared-transmitting cover (1), one infrared emitter (3) per key disposed at the inside (12) of the cover and emitting light collimated virtually perpendicular thereto, one infrared detector (4) adjacent to each infrared emitter which is separated from the latter by a shield (5) opaque to infrared and is pointed at the cover, said infrared detector being located within the main radiation range of the infrared light emitted by the infrared emitter and scattered at a finger (2) but outside the infrared light reflected from the outside and/or inside of the cover.Type: GrantFiled: March 14, 1994Date of Patent: December 26, 1995Assignee: Endress & Hauser Flowtec AGInventors: Thomas Gillen, Wolfgang Brobeil
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Patent number: 5402685Abstract: A circuit arrangement is provided for connect each of a plurality of magnetic flow sensors to a single electronic evaluating unit. Each of the flow sensors includes a measuring tube through which a fluid flows, a coil arrangement, and two measuring electrodes. An electronic evaluating unit includes a processing unit for the potentials of the measuring electrodes, a subsequent digital calibrating and zero-balancing arrangement for generating calibration and zero-offset data, a memory for said data, and a generator circuit for generating the coil current. Through-switching is effected by means of a switching arrangement which includes an optotriac for each flow sensor and an analog multiplexer with double or triple switching paths. The multiplexer switches through the signals from the measuring electrodes. In three further variants, a processing unit is provided in the flow sensor, and a further-processing unit in the electronic evaluating unit.Type: GrantFiled: December 15, 1992Date of Patent: April 4, 1995Assignee: Endress & Hauser Flowtec AGInventor: Wolfgang Brobeil
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Patent number: 5394758Abstract: This mass flow sensor has a vibration-body arrangement through which flows a fluid to be measured and which comprises the following parts: two plane, congruent tube loops each consisting of a straight inlet tube with an inlet end, a straight outlet tube with an outlet end, which ends are fixed in a common mount, and a tube bend interconnecting the respective inlet tube and the respective outlet tube. Mounted at the junctions of the respective inlet and outlet tubes and the associated tube bends is a plate with holes which correspond to the outside diameter of the straight tubes and the tube bends and in which the latter are fixed to determine a respective vibration node. A vibration exciter sets the two tube bends into opposite sympathetic vibrations perpendicular to their respective planes, and two sensors are spaced along the straight tubes for sensing the vibrations of the latter.Type: GrantFiled: November 16, 1993Date of Patent: March 7, 1995Assignee: Endress + Hauser Flowtec AGInventors: Alfred Wenger, Ennio Bitto, Christian Schutze
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Patent number: 5351561Abstract: A Coriolis principle mass flow meter is provided which is insertable into a conduit of a given diameter so as to be axially aligned with the conduit and through which flows a fluid to be measured. The flow meter includes two measuring tubes each having the same inner diameter and the same wall thickness. The two measuring tubes are coupled to an inlet manifold and an outlet manifold. The inlet and outlet manifolds are coupled to an external support tube. The flow meter also includes an internal supporting element that is parallel to the measuring tubes. Opposite ends of the internal supporting element are coupled to the inlet manifold and outlet manifold, respectively. The internal supporting element has a thermal transition resistance to the fluid which is lower than the thermal transition resistance of the external support tube to the fluid.Type: GrantFiled: September 3, 1993Date of Patent: October 4, 1994Assignee: Endress+Hauser Flowtec AGInventors: Alfred Wenger, Ennio Bitto
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Patent number: 5351554Abstract: To provide highly accurate analog-to-digital conversion which is independent of coil-current fluctuations, this magnetoinductive flowmeter is equipped with a pipe made either of nonferromagnetic metal and insulated inside or of electrically non-conductive material, a coil system for producing a magnetic field whose direction is practically perpendicular to the axis of the pipe and which cuts the pipe, a control circuit for controlling a current flowing through the coil system and a measuring resistor, two electrodes which are mounted opposite each other in the wall of the pipe and whose connecting line is practically perpendicular to the pipe axis and to the direction of the magnetic field, and a measuring circuit having its input connected to the electrodes and containing, between its input and its output, the following subcircuits in the order given: a differential amplifier connected to the electrodes, a summer, an analog-to-digital converter which continuously incorporates a reference voltage in the conveType: GrantFiled: May 29, 1992Date of Patent: October 4, 1994Assignee: Endress + Hauser Flowtec AGInventor: Thomas Budmiger
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Patent number: 5321990Abstract: A sensor measures the flow velocity and/or the volumetric flow rate of a fluid flowing in a pipe and in a measuring tube mounted therein, and includes a bluff body disposed in the conduit of the measuring tube, said bluff body being designed to generate Karman vortices and having a blind hole which is in communication with the conduit via passages formed in the bluff body, a vortex sensor inserted into the blind hole and having an electrodynamic transducer responsive to the vortexinduced pressure fluctuations, said electrodynamic transducer supporting a first oscillating body being a sensor sleeve which is deflectable by the pressure fluctuations, has a first cavity sealed from the fluid, and supports a permanent magnet within the cavity, and a second oscillating body movably disposed within the cavity so as to be isolated from the pressure fluctuations and supporting at least one coil located opposite the permanent magnet.Type: GrantFiled: February 26, 1993Date of Patent: June 21, 1994Assignee: Endress+Hauser Flowtec AGInventors: Michael Lang, Karl-Heinz Schulz
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Patent number: 5323156Abstract: An apparatus is provided to avoid linearity errors caused by switching at different frequencies.Type: GrantFiled: October 28, 1992Date of Patent: June 21, 1994Assignee: Endress+Hauser Flowtec AGInventor: Thomas Budmiger
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Patent number: 5280727Abstract: An electromagnetic flow measuring tube is manufactured by forming an inner member which consists substantially of plastic and thereafter coating the inner member with a material which has a lower coefficient of thermal expansion and a higher mechanical strength than the material of the inner member to form an outer member which surrounds the inner member in a form-stabilizing stiffening manner. Thus, when the inner member is formed from plastic in hot condition, as for instance by injection molding, it can cool down and solidify in a relaxed condition, so that it is free of intrinsic mechanical stresses when the outer member is applied. This eliminates the danger of a detachment of the inner member from the outer member and of subsequent occurrence of cracks in the material of the inner member. Mounting flanges, stiffening webs and other structural elements are integrally formed with the plastic inner member. This permits a simple and economic manufacture of flow measuring tubes having a complicated shape.Type: GrantFiled: November 1, 1991Date of Patent: January 25, 1994Assignee: Endress+Hauser Flowtec AGInventors: Peter Hafner, Roland Unterseh
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Patent number: 5218873Abstract: This mass flowmeter is designed to be installed in pipelines having nominal diameters greater than about 150 mm. It has a support tube (11), a vibrating system (12) disposed axially in the support tube and consisting of two straight measuring tubes (21, 22) mounted in a holder (23, 15) at each of their ends, and a vibration exciter (50) which sets each measuring tube into natural-resonance flexural vibration at the center. The soft-magnetic armature (51) of the vibration exciter (50) is secured to one of the measuring tubes, and its electromagnet (52) is mounted in the wall of the support tube (11) opposite the armature (51) via the metallic, nonferromagnetic coil can (53) and contains a soft-magnetic core (54). The central portion (55) of the latter, which is disposed in an energizing coil (57), carries a permanentmagnet inset (58) at the end opposite the armature, and the edge portions (56) of the core (54) extend along the outside of the energizing coil.Type: GrantFiled: January 30, 1991Date of Patent: June 15, 1993Assignee: Endress & Hauser Flowtec AGInventor: Michael Lang
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Patent number: 5210496Abstract: A method and a circuit arrangement for intermittent application of an electrical DC or AC voltage by a switch to an electrode in contact with a material, in particular for cleaning the electrode. The method is suitable in particular for use in electromagnetic flow measuring technology. The objective is to protect the electrode from parasitic capacitances present in the switch and interference voltages occurring therein. This is achieved in that at least in the period in which no voltage is applied to the electrode, the electrical potential of the electrode is coupled to the terminal of the switch which is not allocated to the electrode. Impedance converters are suitable as coupling elements.Type: GrantFiled: October 9, 1990Date of Patent: May 11, 1993Assignee: Endress & Hauser Flowtec AGInventor: Peter Hafner
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Patent number: 5131279Abstract: This sensing element, which is to be installed in a pipeline conducting the fluid to be measured, consists of a straight section of pipe (1) with an unrestricted cross-sectional area and an uninterrupted wall to the external surface of which are positively fixed, successively in the downstream direction and in a spaced-apart relationship: a first resonance absorber (11) at the inlet end consisting of at least one absorber disk (111), a first transducer disk (21) having a first ultrasonic transducer (31) attached to one lateral surface thereof which excites the radial resonance frequency of said first transducer disk (21), a second transducer disk (22) having a second ultrasonic transducer (32) attached to one lateral surface thereof which excites the radial resonance frequency of said second transducer disk (22), and a second resonance absorber (12) at the outlet end consisting of at least one absorber disk (121), the absorber disks (111, 121) being dimensioned so that their respective radial resonance frequeType: GrantFiled: February 1, 1991Date of Patent: July 21, 1992Assignee: Flowtec AGInventors: Michael Lang, Michael Steinacher, Urs Wust
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Patent number: 5105666Abstract: An ultrasonic flowmeter includes first and second ultrasonic transducers which are mounted along a fluid measuring section opposite each other and whose connecting line makes an angle different from 90.degree. with the axis of the fluid measuring section. The transducers can be switched to transmit mode or receive mode by a switching arrangement having first and second switching paths per transducer, one conducting and the other simultaneously nonconducting, or vice versa. One end of the first and second switching paths is coupled to the associated first or second transducer. The first switching paths associated with the first and second transducers having their other ends coupled to the input of a measuring circuit, and the second switching paths associated with said first and second transducers having their other ends coupled to an oscillator.Type: GrantFiled: April 30, 1990Date of Patent: April 21, 1992Assignee: Endress+Hauser Flowtec AGInventor: Michael Steinacher