Sartorius Ag

Sartorius

Sartorius Lab Instruments Gmbh & Co., Kg

Matthias Eger

Eberhard Stadler

Werner Schulze

Christoph Berg

Heinz-Gerhard Kohn

Eberhard Lubke

Erich Knothe

Franz-Josef Melcher

Gunther Maaz

Veronika Martens

Falko Hilbrunner

Steffen Hirche

Herbert Engelhardt

Thomas Fröhlich

Stefanie Meyer

Gottfried Nolte

Michael Muller

Norbert Rogge

Michael MÜLLER

A top-loading balance with a housing, a weighing pan, and a load receptor, wherein the load receptor is connected with a system carrier by a parallel guidance having an upper guide and a lower guide. The system carrier is fixed relative to the housing. One of the guides is divided into two part-guides which, seen in plan view, are disposed preferably on either side of the undivided guide so that the guides do not overlap. In addition, the load receptor, the guides and the system carrier preferably form an integral component. The top-loading balance also includes strain gauges on at least one of the guides to generate a load-dependent electrical signal, which can be measured and converted into e.g. a visual display of the mass. The integral component has two cavities for batteries and the system carrier extends between the two battery cavities. Furthermore, the load receptor is constructed to be approximately U-shaped and the two limbs of the U are disposed laterally near the battery cavities. In addition, the strain gauges are arranged only on the inner side of the undivided guide. Therefore, the top-loading scale is flat and compact without compromising the stability of the scale. Preferably, the balance includes features, such as overload abutments, that protect the delicate parallel guidance, as well as features that ensure accurate measurement of off-center loads.

Flat electronic scales

A lop loaded balance with a load receiver (1, 2, 3) connected by at least one upper (11) and at least one lower guide rod in the form of a parallel guide to a system carrier (4) fixed to the housing, which load receiver, guide rods and system carrier are manufactured from one piece. The system carrier (4, 5, 6, 7) is designed as a frame. The frame-like system carrier is completely surrounded by a second frame (14, 15, 16, 17) supported on the balance feet and that both frames are constructed in a one-piece manner and are connected to one another in such a manner that twistings of the one frame are transferred as little as possible onto the other frame.

Balance with scale on top with a one-piece parallel guide

It is suggested for a balance with one or several weighing cells (1-4, 31) with a total of at least eight wire strain gauges (D.sub.1 -D.sub.4, S.sub.1 -S.sub.4), four of which (D.sub.1 -D.sub.4) are expanded under load and four (S.sub.1 -S.sub.4) compressed under load, in which the eight wire strain gauges are connected together circularly in series so as to form a single Wheatstone bridge which is supplied with voltage along a diagonal (12, 13) (vertical diagonal) and the output signal is taken off along the other diagonal (14, 15) (horizontal diagonal) that a signal is additionally tapped off along the upper horizontal chord (16, 17) and along the lower horizontal chord (18, 19). This makes possible a corner-load adjustment for the balance utilizing the additional signals.

Balance with one or several wire strain gauge weighing cells

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.

Balance with force support

An electronic balance with a system carrier (1) fixed to the housing, a load receiver (2) with two guide rods (3/4) which function as parallel guide, connect the load receiver to the system carried in a vertically movable manner, with four protruding arms (5, 6) which are fastened to the load receiver (2) and carry supports points (7, 8, 9, 10) for a balance scale on their ends and with a low-travel measured value receiver (14, 15) which is loaded either directly by the force of weight acting on the balance scale or with the interpositioning of a translation lever (11). The protruding arms (5, 6) comprise a central recess (19, 20) in front of their ends (17, 18) so that an upper web (21, 23) and a lower web (22, 24) remain and form a parallel guide for the particular support point (7, 8, 9, 10) of the balance scale. Each of the four support points (7, 8, 9, 10) of the balance scale is associated with a wire strain gauge (27, 28, 29, 30) located on one of the associated webs (21, 23). These four or eight wire strain gauges (27, 28, 29, 30) are arranged in such a manner on the webs (21, 23) that they are all expanded, stressed upon an approximately central loading of the balance scale. These four wire strain gauges (27, 28, 29, 30) are wired to two half bridges and the output signals of the two half bridges are added with presettable values to the output signal of the measured value receiver (14, 15).

Electronic balance with parallel guide and scale on top

An electronic balance with scale on top and with parallel guide rods whereby corner-load errors can be corrected by means of the inclusion of at least one leaf spring which is fastened to a load receiver and is supported on the other end on a fixed point of the housing. The magnitude of the correction can be adapted to the corner-load error of the unadjusted parallel guide by means of the selection of the spring stiffness of the leaf spring and/or by means of its effective length.

Electronic balance with scale on top

In an electronic balance with a scale on top with two guide rods which connect a load receiver to a system carrier fixed to the housing as parallel guide, with at least one translation lever which is connected to the system carrier by means of two springs and with a coupling element (9) which transfers the force corresponding to the mass of the weighed material from the load receiver to the shorter lever arm of the translation lever while the counteracting force imposes on the longer lever arm of the translation lever. The two springs and the coupling element (9) are connected to each other by a common cross piece (8) and consist of a single sheet of metal, whereby the thickness of the sheet of metal is greater than the shorter lever arm of the translation lever and the material thickness is reduced in such a manner both in the area of the two springs and in the area of the coupling element (9) that the shorter lever arm is formed by an offset of the thin area (26) of the coupling element (9) produced in the longitudinal direction of the lever in relation to the thin areas (28) of the springs. The length of the shorter lever arm is determined only by the offset of the thin areas (26, 28) of the coupling element (9) and of the springs within the sheet thickness and can be very precisely manufactured by means of suitable manufacturing methods.

In a spring body which is manufactured from a cubical piece, intended for a balance with an upper scale, divided into an upper and a lower guide bar by a horizontal opening extending all the way through it so that the spring body also forms the parallel guide for the balance scale, and which has wire strain gauges at thin spots in the areas of at least one guide bar the width of the spring body is divided at least in the area of the guide bars into two partial areas by a vertical opening which extends all the way through it and does not contact the edge. The vertical opening can have various shapes. The wide spring body has the advantages of in sensitivity to errors caused by off center loading and allowing the scale to be connected to the parallel-guided part of the spring body at two or three points, which reduces the stability requirements of the scale. The strain gauge are advantageously distributed so that one half of them is on each of the two areas of spring body. The strain gauges can be applied in various configurations.

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Wollbrandshausen, Germany

Matthias Eger