04703161 is referenced by 182 patents and cites 4 patents.

This invention provides a ruggedized calculator having shock-absorbant layers around a relatively unbreakable hard plastic case. Flotation cells enable this unit to float and various seals render it dust-proof and water-tight. Power can be selectively supplied from a solar unit or rechargeable batteries. The keypads are large so they can be manipulated with gloves on and membrane switches prevent dirt, dust, and moisture from reaching the electronics package.

Title
Ruggedized calculator
Application Number
6/913713
Publication Number
4703161
Application Date
September 30, 1986
Publication Date
October 27, 1987
Inventor
Roger D McLean
2111 W. Dixon, Mesa, 85201
AZ, US
Agent
LaValle D Ptak
IPC
G06C 5/02
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