GB351007A
(https= )
US2091778A
(en )
1937-08-31
Keyboard construction and key control
US2834289A
(en )
1958-05-13
Zero printing device
US2678160A
(en )
1954-05-11
Key-responsive recording
US2705106A
(en )
1955-03-29
Calculating machines
US1840424A
(en )
1932-01-12
Calculating machine
US1811353A
(en )
1931-06-23
Fornia
US2805822A
(en )
1957-09-10
Totalizer controlling mechanism for accounting machines
US2662690A
(en )
1953-12-15
Numeral wheel locking mechanism
GB401904A
(https= )
US2369574A
(en )
1945-02-13
Locking mechanism for typewriting
GB514291A
(https= )
US1646105A
(en )
1927-10-18
peters
US1929625A
(en )
1933-10-10
Calculating machine
GB191403083A
(en )
1915-02-05
Improvements in Adding Machines.
GB381158A
(https= )
US3429503A
(en )
1969-02-25
Cash registers and like adding machines
US3595473A
(en )
1971-07-27
Calculating machine with a device for rounding off an amount and for cancelling decimal positions
US1804103A
(en )
1931-05-05
Werke aktiengesellschaet
US1028149A
(en )
1912-06-04
Adding-machine.
GB540315A
(https= )
GB703886A
(https= )
1900-01-01
GB760381A
(https= )
GB487494A
(https= )
GB545438A
(https= )