Sartorius Weighing Technology Gmbh

Jochen Doerner

Detlev Erben

Christian Schrader

Ralf Mueller

Helga Covic

A top-pan balance having a pan, a weighing system, and an overload safety mechanism. The load cell () of the weighing system is connected to fixed points () on a housing of the weighing system by an upper connecting rod () and a lower connecting rod () as a parallel guide so as to be movable in the vertical direction. The pan is attached to a pan support () for securing against overload, the support being connected to the load cell through an auxiliary parallel guide () and through a biased spring element (), whereby the pan is quasi rigidly coupled to the load cell in the permissible weighing range, but is only resiliently coupled to the load cell when the permissible weighing range is exceeded. At least one limit stop is fixed to the housing and limits the elastic deflection of the pan and the pan support in case of overload. An additional corner load sensor is provided between the pan support and the load cell, and the corner load sensor and the overload safety mechanism form a common assembly (), wherein the corner load sensor is disposed behind the overload safety mechanism in the force flow direction from the pan to the load cell. Furthermore, the assembly is attached on the side of the load cell facing the connecting rods and extends into the space between the connecting rods.

Top-pan balance with an overload safety mechanism and a corner load sensor

A weighing scale, e.g. a top-pan scale, having a scale pan () supported on a force transducer, and a corner load sensor () measuring the tilting of the scale pan () relative to the force transducer. The corner load sensor includes a light beam source () emitting a first light beam and a second light beam. The first light beam and the second light beam are directed toward a reflecting surface on an underside of an arrangement that includes the scale pan (). The first light beam and the second light beam are respectively inclined relative to the reflecting surface of the untilted scale pan (). The corner load sensor () of the scale also includes a first optical sensor () measuring the first light beam reflected by the reflecting surface. If no corner load exists, a predetermined proportion () of the reflected first light beam is directed to the first optical sensor (). If the scale pan () is tilted, the proportions of the reflected light beams which fall on the two optical sensors () change. The corner load sensor () has an evaluating unit determining the tilt of the scale pan () dependent on the light quantities measured with the two optical sensors ().

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Goettingen, Germany

Jochen Doerner