the Keller letter scale from Switzerland
This special letter scale was made by Max Keller A.G. from Pfäffikon in Switzerland. The unequal arms balance has a permanent hanging red ball weight on the left. On the other side there are two movable weights, one for steps per gram and a larger weight for steps per 20 grams. The maximum weighing range is 500 grams. At the end of the long balance arm a magnetic damping is placed to stop the arm more quickly. In the meantime, the ball weight continues to oscillate cheerfully. The scale is stamped with Swiss calibration marks ZH4 (Zürich/Winterthur) and a mark 76, presumably the inspection year 1976. The main pivot point is a knife support, the implementation is of Swiss quality. The weighing platform also rests on a knife support. The base has a screw to set the scale to zero. The letter tray is 24 cm high, the overall length is 31.5 cm. The foot dimensions b x d = 20 x 15 cm. I also saw this letter scale with a black ball weight. Below some more images of the Keller letter scale.
back of the Keller letter scale
