Bizerba airmail letter scale
This special and also rare scale is an airmail letter scale, in German: Luftpostbriefwaage. The Bizerba Waagenfabrik, Wilhelm Kraut Kommanditgesellschaft, from Balingen in Württemberg in Germany is the maker. The operation of scales mechanism is special. After a letter or other burden has been placed on the scale, a pointer moves upwards. By turning the large central adjustment knob clockwise, the dial rotates clockwise and at the same time the clockwise rotation of the adjustment knob further tightens a spiral spring. As a result, a new equilibrium position is set by hand, the pointer descends again to the fixed pointer and is then again in line with the red line. The scale can then be read. The corresponding postage value, depending on the type of mail, is shown behind the red line on the chart. These German postage values date from the period September 1, 1948 - July 1, 1954. The mail types for which the postage values are on the scale are: samples, printed matter, letters, domestic airmail letters and airmail letters to countries within Europe.
After removing the letter or the weighing load, the pointer moves down. By turning the large central adjustment knob counterclockwise, the dial rotates counterclockwise and at the same time turning the adjustment knob counterclockwise reduces the tension of the spiral spring. As a result, a new equilibrium position is set by hand, the pointer rises again to the fixed pointer and is then again in line with the red line. The zero position is now back. The scale has knife-edge bearings on the side of the hanging letter scale. The spiral spring and the arm of the pointer together have a cone shaft bearing. An adjusting knob protrudes from the scale housing on the left. With this, this airmail letter scale can be set precisely to zero.
back of the airmail letter scale
