Underwood Sundstrand 11240SP Adding Machine

This hefty ten-key listing electric adding machine has a gray metal case with a 13” carriage. The block of nine white number keys has a zero bar below. Numbers of up to ten digits may be entered. To the left are correction, back space, and repeated addition keys. To the right are subtraction, addition, and no total keys. Left of these keys is a lever that can be set at “SHUTTLE” or “NORMAL.” Another lever can be set at “REG.B,” “A*B,” or “REG.A.” Another lever is unlabeled. Above the keyboard is a place indicator. Behind this are the printing mechanism, carriage, and cross-footer. Numbers of up to 11 digits can be printed. The machine has a two-colored ribbon. Tabs can be set to print columns at different locations along the platen, different sizes of paper can be used, and there are knobs for advancing the platen on both sides. The motor also is at the back.
This is model #303 from the Patent Division of Burroughs Corporation. It is marked on the back: Underwood (/) Sundstrand (/) Product of (/) Underwood Corporation (/) Protected by United States (/) and Foreign Patents (/) Made in U.S.A.. It is also marked there: 775180 (/) 11240SP
Compare to the Underwood Sundstrand Adding Tabulator (model 11240SP-13), described in 1990.188.07.
Currently not on view
Object Name
adding machine
date made
Underwood Corporation
Physical Description
metal (overall material)
rubber (overall material)
paper (overall material)
plastic (overall material)
overall: 33 cm x 47 cm x 49 cm; 13 in x 18 1/2 in x 19 9/32 in
place made
United States: Connecticut, Hartford
ID Number
maker number
775180 [/] 11240SP
accession number
catalog number
Science & Mathematics
Adding Machines
See more items in
Medicine and Science: Mathematics
Adding Machines
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of Burroughs Corporation
Additional Media

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