Patents are the DNA of inventions, spawning entire new industries, businesses and economies. A new study by the Brookings Institution finds the most productive periods in the United States occurred during the early 20th century and the Great Depression. There’s also been a patent boom in the past four years and the rate of patenting is nearly as high today as at any time in U.S. history. The most patents (per capita) came in 1916, 1915, 1885, 1932, 2010, 2011, 1931, 1883, 1890, and 1917. Here’s a look at some inventions from those years:
1883: Thomas Edison's Voltage Regulator 
 Superstar-inventor Thomas Edison has claimed more than 1,000 patents, 
including the phonograph, light bulb and this electronic device that was
 key to the development of radio, television and computer transistors. 
1885: Machine Gun 
American-born
 British citizen Hiram Maxim invents a self-powered portable and 
fully-automatic machine gun that changes warfare. Its effects on society
 and the constitutional right to own it are still being debated today.
1890: Stop Sign 
William 
Phelps Eno proposed the first set of traffic rules and signs in an 
article in Rider and Driver, although the first actual sign didn’t 
appear until 1915.
1915: Stainless Steel Sink 
The
 discovery of a new “rustless” steel by British metallurgist Harry 
Brearley is announced in the New York Times. Brearley applied for a 
patent that year, but American Elwood Haynes beat him to it. Its shiny 
surface, strength and corrosive resistant properties revolutionized 
modern industry from skyscrapers to kitchen utensils, trains and planes 
to medicine.
1916: Condenser Microphone 
Edward
 C. Wente of New Jersey’s Bell Labs invents the electronic condenser 
microphone, which can be found today in recording, television, film and 
radio studios.
1917: Modern Zipper 
Gideon
 Sundback figures out that 10 fasteners per inch works much better than 
four and invents the modern zipper, or “separable fastener.” Used to 
close boots and tobacco pouches, the zipper doesn’t get into clothing 
for another 20 years.
1931: Stop-action Photography 
Harold
 “Doc” Edgerton began playing around with strobe lighting while a grad 
student at MIT, developing both stop-action and ultra-high speed 
photography. His images of exploding bullets, running athletes and milk 
droplets became iconic photos. He went on to invent underwater 
time-lapse photography, atomic bomb timing and lights for copiers and 
flash photography. 
1932: Polarizer 
Edwin 
Land invents the polarizer, which filters light waves and reduces glare.
 He goes onto invent instant photography, while the polarizer leads to 
sunglasses, camera filters and LCD's. 
Apple debuted
 its iPad tablet in April 2010. Its history goes back to 1983, when 
Apple CEO Steve Jobs said he wanted to build a computer that users could
 carry around like a book, plug into telephone communications and link 
to libraries and other databases. The firm sold 23 million in the last 
quarter of 2012; total sales now top 100 million. 
2011: Stark Hand
This 
prosthetic hand is cheaper, lighter and doesn’t need wires or batteries.
 Garage inventor Mark Stark came up with this device to help a neighbor 
who had been born without a hand. It's now under commercial development.
Source: news.discovery.com 
 
 
