BISCHOFF
letter scale

This huge letter scale bears the name of the maker V. Bischoff from Munich in Germany. The stand height of this letter scale is 50 centimeters, the highest point of the suspension bracket of the scale is even 55 centimeters high. The designer of the letter scale is Alois Heckenstaller, from Straubing in Bavaria. This is stated in a German patent DE36955 that was already granted on July 22, 1885! Characteristic is the low-friction bearing with still a large angle of movement: a knife-edge support rests in a pan which in turn is movable mounted thanks again to knife-edge bearing. Also the suspension bracket of the hanging scale part has a knife-edge bearing. This results in an extremely sensitive scale. This letter scale is numbered 3321. This number is on a lot of the parts. A view small parts only have the last two digits: 21. The back of the figures scale has in addition to the whole number 3321 and the truncated number 21 the name BISCHOFF in stamped-in letters, and no initial here. I don't know when this letter scale was produced nor when it was verified for the first time. Maybe the verification office has the answer to the last question. These letter scales were used until the eighties of the last century and verified by the German Verification Offices for example Eichamt Bayreuth. This specimen was disapproved by that Office. With a lead secured wire a card of disapproval was attached to the base of this letter scale. According to this card the letter scale needs to be offered for recalibration before April 15, 1973. I removed the card and and overhauled the light damaged knife-edge bearing myself. As to proof verifications year marks are stamped into the lead bet of the weighing arm. These year marks are partly scratched off, 53, 60 and 63 still can be distinguished. This Bischoff has a unique double scale: with the weight folded up the top scale of zero to 250 grams is used, when the weight is folded down, the scale of 250 to 500 grams has to be used.