Lindholm

Single row keypad adding machine

1886

Of this early American single-row key adder, only this one copy is known. The patent granted on June 15, 1886, was issued to Peter T. Lindholm of Lindsborg, Kansas. Similar to the single-row key adding machine Centigraph (cf. Inv.-No. FDM 6122), the Lindholm works by moving a large ratchet wheel, which is advanced by the keys (1...9) with different stroke lengths via a connected swinging ratchet. The ratchet wheel is connected to a large number ring that can represent amounts from 00 to 99. In addition, there is another small counting wheel next to the ratchet wheel, which shows the hundredth digit. This counting wheel is cleverly connected to the large counting wheel via a gear transmission, so that counting up to 699 is possible. The key 0 enables the adding machine to be zeroed. A spiral spring, which is tensioned during the addition, enables an automatic return. The machine is very nicely ornamented.