Mettler-toledo Ag

Mettler-toledo Gmbh

Mettler-toldeo Ag

Hans-Rudolf Burkhard

Andreas Metzger

Ferdinand Schneider

Stephan Baltisberger

Jean-Christophe Emery

Peter Schilling

Dominique Genoud

Luzi Hess

Thomas Köppel

Chun Yang

Daniel Reber

Chao Wu

Daniel Schrag

Christoph Trautweiler

Naifeng Bian

Weixiang Sun

Christophe Béguin

Daniel Rupp

Yves Marmier

Feng Xu

Jean-Maurice Tellenbach

Urs Loher

Volker Ziebart

Markus Uster

Thomas Koeppel

George Fankhauser

David Koller

Ernst Tschopp

Willi Graf

Thomas K&ouml;ppel

Hans De Waal

Erwin Kaderli

Bruno Bonino

Franz Balsen

Qihao Yuan

Arne Burisch

Roman Haefeli

Markus Bendler

Bruno Lüchinger

A parallel guide of a force transmission device has movable and fixed parallel legs, and first and second parallel guiding elements. Thin-point flexional bearings connect the parallel legs to the parallel guiding elements. The movable parallel leg is guided by the parallel guiding element on the fixed parallel leg. A force transmission lever, arranged on the fixed parallel leg, has a lever bearing, and a first lever arm. The force transmission lever is pivotably mounted on the lever bearing and the first lever arm is connected to the movable parallel leg to transmit force. The force-transmitting connection is produced by a coupling element having at least one further thin-point flexional bearing, with at least one functional region of the force transmission device being formed monolithically. A functional region associates at least one bearing point with at least one of the parallel legs, the force transmission lever, and the coupling element.

Monolithic weighing cell with bearings formed by additive manufacturing

A calibration weight assembly () has at least one calibration weight () and a transfer mechanism, and is used with a gravimetric force-measuring device () having a fixed region (), a load-receiving region (), and a measuring sensor (). The transfer mechanism has at least one poly-stable positioning element (), a first stable state of which defines a calibration position (KP) and a second stable state of which defines a resting position (RP) of the transfer mechanism. The at least one calibration weight can be coupled with the load-receiving region. The transfer mechanism, as actuated by the measuring sensor, transfers the at least one calibration weight from the calibration position to the resting position, or vice versa.

Calibration weight assembly for a gravimetric measuring device

A load cell is provided with protection against damage from overload. The load cell has a load receiving member, a main member and a load transmitting member. The main member has a movable portion, a fixed portion and a first parallel guiding member for connecting the fixed portion and the movable portion. The load transmitting member has a first mounting portion for mounting the load receiving member, a second mounting portion for mounting the movable portion and a parallel guiding member for connecting the first mounting portion to the second mounting portion. The first mounting portion is movable vertically relative to the second mounting portion when a load being applied on the first mounting portion. The load-transmitting member is a single piece. The load cell also has a stop portion for preventing the first mounting portion from further moving downwardly for overload protection.

Load cell with streamlined structure and overload protection

A parallel-guiding mechanism in accordance with the present invention comprises a load-receiving portion for receiving a load of a to be weighed object; a fixing portion including an end portion, an extending portion extending forwardly from the end portion and mounting portions extending forwardly from the extending portion, and parallel-guiding members connecting the load-receiving portion to the fixing portion. The mounting portions include a first mounting portion and a second mounting portion. A receiving space is formed between the first mounting portion, the second mounting portion and the extending portion for receiving at least a portion of the load-receiving portion. A containing space for receiving the extending portion is formed between the parallel-guiding members, the load-receiving portion and the end portion. The parallel-guiding members include an upper parallel-guiding member and a lower parallel-guiding member. The load-receiving portion, the fixing portion and the parallel-guiding members are formed integrally of one piece of solid material.

Weigh module with parallel-guiding mechanism module

A force exerted by a load is determined in a force-measuring device () operating under electromagnetic force compensation. The device includes a measurement transducer () with a coil () movably immersed in a magnet system () and a force-transmitting mechanical connection between a load-receiving part () and the coil or magnet system. A position sensor (), also part of the device, determines a displacement of the coil from its settling position relative to the magnet system () which occurs when the load is placed on the load-receiving part. An electrical current () flowing through the coil generates an electromagnetic force between the coil and the magnet system whereby the coil and the load-receiving part are returned to, and/or held at, the settling position. The magnitude of current and the amount of displacement are used to determine the weight force exerted by the load.

Digital linearization in a weighing cell

A force-measuring device () with a parallelogram linkage has a measurement transducer coupled to it. A coil () of the transducer has guided mobility in a magnet system () and can carry an electric current (). A position sensor () detects the deflection of the coil () from a balanced position relative to the magnet system when a load is placed on the force-measuring device. The electric current () flowing through the coil (), by way of the interaction between the coil and the magnet system, returns the coil and the movable parallel leg to the balanced position. A system-characterizing means () is established in a processor unit (). The system-characterizing means and an unchangeable system reference means () are compared to determine the functionality of the device. The functionality is verified by the magnitudes of the electric current and the deflection of the coil from its balanced position.

Diagnostic method for a weighing cell

The force-transmitting mechanism () includes a parallel-motion guide mechanism with a movable parallel leg (), a stationary parallel leg, and at least two parallel-guiding members (), wherein the parallel legs and the parallel-guiding members are connected to each other by flexure pivots and the movable parallel leg is constrained to the stationary parallel leg in guided mobility by the parallel-guiding members. The force-transmitting mechanism further includes a force-transmitting lever () which is pivotally supported on a fulcrum pivot () arranged on the stationary parallel leg, with a first lever arm () having a force-transmitting connection to the movable parallel leg by way of a coupling member (), and a second lever arm () to which a measurement transducer () can be attached through a force-transmitting connection. The second lever arm includes a first partial lever arm (A) and a second partial lever arm (B), wherein the first partial lever arm is designed to receive the compensation force generated by the measurement transducer, and the second partial lever arm is designed for the detection of a displacement of the pivotally supported force-transmitting lever relative to a null reference of a position sensor ().

Force-transmitting mechanism with a separate lever arm extending to a position sensor

Eccentric loading errors of a weighing cell () with a parallel guiding mechanism are determined and corrected or at least reduced. The weighing cell has a test weight actuating device (), by which at least one test weight () is positioned successively on at least three test weight support points () of the test load receiver () that do not lie in a straight line. A processor unit () uses a control signal (S) to position the test weight on the support points. A test weighing signal (T) is generated for each support point, and from these, eccentric loading errors are ascertained. A device for correcting the eccentric loading errors uses control signals (S) from the processor unit to make a geometrical-mechanical change in the parallel guiding mechanism, using a first and a second actuating unit.

Weighing cell with a device for correcting eccentric loading errors and a method for correcting eccentric loading errors

A force-measuring device () for a gravimetric measuring instrument has a stationary part () and a load-receiving part (). Parallel guide members () connect the receiving parts. The device also has at least one balance beam () connected to the load-receiving part through a coupling element () acting on a first lever arm () thereof, and which, at a second lever arm () thereof, is connected to a measurement transducer () which is arranged on the stationary part. Further levers () can be arranged, respectively, between the first lever arm and the load-receiving part, and between the second lever arm and the measurement transducer. At least one sliding weight (A,B) is arranged on the at least one balance beam, wherein the position of each of the sliding weights present can be varied in a controlled way by means of at least one drive mechanism.

Force-measuring device with sliding weight

A parallel-guiding mechanism () has a movable parallel leg (), a stationary parallel leg (), a first parallel-guiding member () and a second parallel-guiding member (). The parallel legs and the parallel-guiding members are connected to each other by flexure pivots, in the form of narrow material connections. There is at least one adjustment zone (). An adjustment flexure fulcrum () is arranged between a flexure pivot () and a parallel leg. The adjustment zone is connected to the first lever end () of an adjustment lever (). The adjustment flexure fulcrum forms the lever fulcrum () of the adjustment lever, which has an elastic domain with a section modulus that is smaller than a section modulus of the adjustment flexure fulcrum.

Device and method for the adjustment of an eccentric load error in a parallel-guiding mechanism

A force-transmitting mechanism of a gravimetric measuring instrument, with a stationary portion, and a load-receiving portion that is joined through a force-transmitting connection to a measurement transducer that is arranged on the stationary portion. A calibration weight may be coupled to the force-transmitting mechanism in such a way as to minimize the degree to which changes of the geometry can affect the force that the calibration weight exerts on the measurement transducer.

Force-transmitting mechanism with a calibration weight that can be coupled and uncoupled

A weighing cell based on the principle of electromagnetic force compensation. A permanent magnet system is mounted on a base part and includes an air gap within which is suspended a coil that is connected to a load receiver through a force-transmitting mechanism. The coil carries an electrical compensation current when the weighing cell is in operation. An optoelectronic position sensor is also included, and its signal corresponds to the deflection of the coil from a zero position which occurs as a result of placing a load on the load receiver. A closed-loop controller regulates the compensation current in response to the sensor signal in such a way that the coil and the load receiver that is connected to it are returned to their zero position by the electromagnetic force that is acting between the coil and the permanent magnet.

Weighing cell based on the principle of electromagnetic force compensation with optoelectronic position sensor

A force-transmitting mechanism () has stationary and load-receiving portions (). The load-receiving portion is joined to a measurement transducer on the stationary portion through a force-transmitting connection, directly or through at least one coupling element () and at least one lever (). The force-transmitting mechanism has a parallel-guided coupling means (), a calibration lever () with a fulcrum on the stationary portion, and calibration lever arms (), one of which is rigidly connected to a calibration weight (). The parallel-guided coupling means () is arranged between the second calibration lever arm and the at least one coupling element or an arm () of the lever. The parallel-guided coupling means is divided into fixed and parallel-guided coupling parts (), which allows a force to be transmitted between the coupling parts. Parallel elements of the parallel-guided coupling part absorb relative traverse displacements from transmitted forces.

A load carrier with a receiving pan for a free-flowing substance, a calibration weight holder for supporting a calibration weight, and a connector element for connecting the load carrier to a load receiver of a weighing cell. The receiving pan is arranged between the connector element and the calibration weight holder and is designed to be loaded with the free-flowing substance through a passage in the calibration weight holder. The calibration weight holder can be loaded with a calibration weight independently of the load status of the receiving pan.

Load carrier

The disclosed embodiments describe force-transmitting devices for use in gravimetric measuring instruments. The force-transmitting devices scale the force from a calibration weight to facilitate calibration and weighing. The devices comprise unidirectional coupling elements. The unidirectional coupling element comprises coupling element parts. The elements may be adapted to transmit only a tensile force or only a compressive force to a measurement transducer. Adapting the unidirectional coupling element to transmit one type of force or the other may be done by selecting an appropriate arrangement of coupling element parts. The coupling element parts are adapted to transmit force along a midline axis by either a projection and v-shaped groove coupling or projections on the first part mated with surfaces on the second part adapted to receive and guide the first part.

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Wila, Switzerland

Hans-Rudolf Burkhard