Ishida Co. Limited

Shoko Tajiri

Yukio Wakasa

Kazufumi Naito

Shinji Takeichi

Yoshihiro Nakamura

Kazuteru Oda

Yoshinori Tarumoto

Kohei Hayashida

Hidekatsu Tokumaru

Hiroki Fujioka

A weighing apparatus includes: a transport unit capable of transporting an article; a weighing unit connected to the transport unit and configured to output an original signal related to a weight; and a weighing control unit configured to output a weighing value of the article by processing the original signal, wherein the weighing control unit is configured: to determine whether or not to adjust a zero point on the basis of a determination signal obtained by applying a first filter to the original signal; to generate an adjustment signal obtained by applying a second filter having more stages than the first filter to the original signal or the determination signal in a case where it is determined that the zero point is to be adjusted; and to perform adjustment of the zero point on the basis of the adjustment signal.

Weighing apparatus

The load cell includes a strain generating body having a strain generated portion, and a strain detection element provided on a surface of the strain generating body in a portion corresponding to the strain generated portion and having an inversion portion and a straight portion. A creep characteristic is adjusted by a thickness of the strain generated portion in a portion corresponding to the inversion portion.

Load cell

A weighing machine, such as a combinational weighing machine, has scale cells and a plurality of dummy cells installed on the same floor. The scale cells output weight signals corresponding to the weights of objects being loaded. The mode of vibrations of the floor is detected from dummy signals from the dummy cells, vertical displacements of the floor at the positions of the scale cells are calculated, and their effects are eliminated from the weight signals. Those of the scale cells not selected after a cycle of combinational calculations can be used as dummy cells in the next cycle. A memory device may be provided to store preferred combinations of such scale cells not selected that may be used for this purpose. Effects of the floor vibrations can be eliminated more accurately if the differences in sensitivity among the cells due to physical characteristics of the individual cells and/or due to the different loads on them can be taken into account either by a feedback calculation or by a formula.

Method of and means for correcting effects of floor vibrations on weight

A weighing machine, such as a combinational weighing machine, has scale cells and a plurality of vibration-detecting cells installed on the same floor. The scale cells output weight signals corresponding to the weights of objects being loaded. The mode of vibrations of the floor is detected from signals from the vibration-detecting cells. Vertical displacements of the floor at the positions of the scale cells are calculated therefrom, and their effects are removed from the weight signals. A control device is provided such that the effects of floor vibrations are ignored if they are sufficiently weak.

Weighing machines with means for correcting effects of floor vibrations

A weighing method and apparatus includes a weighing cell for weighing an article and outputting a weighing signal corresponding to the weight thereof and a floor vibration detecting cell for detecting vibration of a floor on which the weighing cell is installed and for outputting a floor vibration detection signal. The weighing signal and the floor vibration detection signal are selectively sampled at a predetermined sampling frequency and an A/D converter converts each of the sampled signals into a digital weighing signal or a digital floor vibration detection signal, respectively. A first digital filter filters the digital weighing signal and a second digital filter filters the digital floor vibration detection signal. A floor vibration compensator subtracts the filtered digital floor vibration detection signal from the filtered digital weighing signal and outputs a floor vibration compensated signal wherein an error of the weighing signal caused by the floor vibration is compensated for. A phase corrector nullifies a phase difference, caused by a difference in the times at which the weighing signal and the floor vibration detection signal are sampled, by applying a suitable correction, corresponding to the phase difference, to the weighing signal or the floor vibration detection signal before or after filtering.

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Shiga, Japan

Shoko Tajiri