Uploaded August 2024 | Updated September 2026, 2 weeks ago
Patented in 1956 by Sergio Lanza, the Swift Handy Calculator (originally the Addimat / Addipresto) was a simple mechanical addition/subtraction machine using a unique ratchet-and-pawl mechanism. Due to its only being patent-protected in Italy, numerous cheaper clones of the design were produced by foreign companies under brand names such as Swift, Bentley, Schnellrechner, and Add-o-Matic.
SOURCES
jaapsch.net/mechcalc/schnellrechner.htm
worldwide.espacenet.com/patent/search/family/032357978/publication/GB189904489A?q=pn=GB189904489
worldwide.espacenet.com/patent/search/family/032357978/publication/GB189904489A?q=pn=GB189904489
rechnerlexikon.de/en/artikel/Lanza,_Sergio
rechnerlexikon.de/en/artikel/Patent:IT554094
bob-mockford.co.uk/museum/calculating
rechnen-ohne-strom.de/rechner-galerie/addiermaschinen/griffeladdierer
https://www.johnwolff.id.au/calculators/adders/adders.htm#Addipresto648
Patented in 1956 by Sergio Lanza, the Swift Handy Calculator (originally the Addimat / Addipresto) was a simple mechanical addition/subtraction machine using a unique ratchet-and-pawl mechanism. Due to its only being patent-protected in Italy, numerous cheaper clones of the design were produced by foreign companies under brand names such as Swift, Bentley, Schnellrechner, and Add-o-Matic.
SOURCES
jaapsch.net/mechcalc/schnellrechner.htm
worldwide.espacenet.com/patent/search/family/032357978/publication/GB189904489A?q=pn=GB189904489
worldwide.espacenet.com/patent/search/family/032357978/publication/GB189904489A?q=pn=GB189904489
rechnerlexikon.de/en/artikel/Lanza,_Sergio
rechnerlexikon.de/en/artikel/Patent:IT554094
bob-mockford.co.uk/museum/calculating
rechnen-ohne-strom.de/rechner-galerie/addiermaschinen/griffeladdierer
https://www.johnwolff.id.au/calculators/adders/adders.htm#Addipresto648
