This letter scale is an invention of Karl Otto Schmidt. The mechanism is described in the German patent DE2321288 of November 7, 1974. The transmission of the vertical movement of the spring scale into a horizontal movement of the indicator, is the main characteristic. The patent was supplemented by the German patent DE2340838 of February 27, 1975. This described a fine tuning of the mechanism with the application of a little magnet. The housing and the plate are made of plastic. Besides this bright yellow version, this scale was also available in e.g. chrome color, green and black. The capacity is 350 grams. Other models range up to 250 grams or up to 500 grams. A zero leveling screw is placed at the back. Additional patent information is given at chrome color. Below some more pictures of this scale.
letter scale, maker Gebr. Schmidt
