(CNN) -- It was a woman's raw, bleeding hands that led Jock Brandis to make a promise.
Jock Brandis shows some African men how to use a device that shells nuts, helping make more money for the village.
In 2002, Brandis was helping a friend repair a water treatment system in a Mali, Africa, village. There, he encountered a woman whose hands were bleeding from shelling peanuts to support her family -- and this was not uncommon.
In Africa alone, women spend 4 billion hours a year shelling peanuts by hand, according to the Peanut Collaborative Research Support Program.
"A sun-dried peanut is like a little rock. It's that hard," says Brandis. "Cracking the shells takes hours of effort for the village women who traditionally do the chore, and it often leaves their hands bloody."
Brandis promised the women in the village he would return in a year with a machine to speed the shelling. That turned out to be easier said than done.
"When I went back to America, it didn't exist," recalls Brandis.
So he started asking around.
"I didn't know much about peanuts, so I guess I did what any Canadian with a question about peanuts would do. I wrote Jimmy Carter," Brandis said.
Through former President Jimmy Carter's library, Brandis tracked down an expert who suggested he look at a sketch from a Bulgarian scientist. Brandis attempted to replicate the sketch, but it didn't work. Having tinkered and toiled with "gizmos" as a former gaffer in the film industry, Brandis set out to make a peanut sheller himself.
After fiddling, cranking and grinding his way through a number of prototypes in his Wilmington, North Carolina, studio, Brandis developed a simple machine that could shell nuts up to 50 times faster than by hand. Designed with a simple, durable hand crank, the "universal nut sheller" could be built with $28 worth of materials.
To give this "gift to the world," Brandis joined forces with a group of former Peace Corps volunteers and co-founded the Full Belly Project in 2003, a nonprofit organization dedicated to designing and distributing technologies like the universal nut sheller. Brandis travels with others to developing countries to show local shellers how to use and make the machines themselves. Watch Brandis show one of the most efficient peanut shellers »
"It makes their work less tedious and increases productivity up to 50 times," says Brandis. "One machine will work for an entire village, so when we're talking about 100 machines, we're not talking about 100 families -- we're talking about 100 villages."
Not only does Brandis refuse to patent the device, but designs for the shelling machine also are available online for anyone to download, assemble, duplicate or improve upon, which Brandis encourages.
"One of the great things that happened is that when this machine went out, we started getting word back from all over the world saying, 'Oh, we don't use it for peanuts. We use it for shea, for jatropha, for coffee,' " he says. "It's now become much bigger than just being a peanut sheller." Watch Brandis talk about adapting his invention to shell other nuts »
The Full Belly Project works on four continents in 17 countries. Hundreds of machines are in use or being produced locally at minimal cost in the Philippines, Uganda and Guatemala, resulting in health benefits and increased family incomes, according to the Full Belly Project.
"I get up in the morning and there's an e-mail from a total stranger and a picture," says Brandis. "It's a happy person standing beside their machine with a big grin. That's the [moment] I live for." E-mail to a friend