Its formal name was the “man-carried auto-navigation device,” but it went by the nickname “Man Can.” The Martin-Marietta Corporation received patent no. 3,355,942
for it in 1967.
It was a device designed to help soldiers avoid getting lost. The patent offered this description:
a lightweight, completely mechanical, low energy device by which small units of men may locate themselves accurately with respect to some reference point when operating in the jungle, darkness or bad weather without dependence upon visual landmarks.
It combined a compass and a pedometer. A GI would record his initial location on a map, and then the device would track his footsteps and the directions in which he turned. When he was done walking, the device would tell him his new coordinates.
A key feature of the device was that it didn't use any battery power. So the GIs would never need to worry about it running out of juice. It operated via a bellows located in the heel of the GI's shoe.
I can't find any follow-up reports about how well this gadget worked. Apparently not well enough to warrant its adoption by the army. But it was an interesting concept.
Allentown Morning Call - Dec 11, 1967
Category: Geography and Maps | Inventions | Patents | Military | Technology | 1960s