Inventors - a Series - (2) Who Invented the Microwave Oven?

Percy Spencer was born in Howland, Maine in 1894. He became an orphan early on and was raised by his aunt and uncle. Percy never graduated from grammar school since he was forced to leave school early to help out his aunt when his uncle passed away.

His first job was at a paper mill that was planning to begin using electricity. Percy's job was to install electricity in the plant even though he had never received any formal training in electrical engineering. When he joined the navy at the age of 18, Percy became a self-taught expert in radio technology. While standing watch at night, he also taught himself trigonometry, calculus, chemistry, physics and metallurgy, among other subjects.

Following his service in the navy, he went to work at Raytheon and quickly became the company's expert in tube design. He supervised the mass production of magnetrons which produce microwaves and provide power to radar equipment, which proved to be of great value to allied forces during World War II. The microwaves were able to spot Nazi warplanes on their way to bomb the British Isles.

The microwave oven was invented by accident by Percy Spencer. At Raytheon, while working on a radar research project, he was testing the vacuum tubes known as magnetrons. While standing near the equipment, Spencer experienced a tingling sensation and noticed that a chocolate bar in his pocket, a Mr. Goodbar, had melted. Concluding that the magnetron had caused the candy bar to melt, he tested his theory using popcorn. Sure enough, the kernels popped, creating the first microwave popcorn.

Spencer constructed a metal box into which he fed a magnetron tube. This became the prototype microwave oven although it was nearly six feet tall and weighed over 700 lbs. The company filed a patent in 1945 for the microwave oven and named it the Radarange. Years later, in 1967, Raytheon manufactured the first countertop microwave ovens, which cost about $500 each. As a matter of interest, in 1969, the Apollo astronauts returned to Earth and were quarantined for some time. They cooked their meals on one of the first counter top microwave ovens.

Microwaves are not absorbed by most plastics, glass or ceramics, which makes them perfect for heating food without heating the food containers. Microwave ovens also use less energy than other cooking appliances.

For his invention, Spencer received no royalties. He was paid a one-time, two-dollar gratuity from Raytheon - the token payment the company made to all inventors on its payroll at that time, for company patents. Had he held the patent, Percy Spencer would have been one of the world's richest men.

Spencer became Senior Vice President and a member of the Board of Directors at Raytheon, receiving 150 patents during his career. He was also awarded the Distinguished Service Medal by the U.S. Navy and has a building named after him at Raytheon. Percy Spencer died in 1970.

Date: 2023-04-10     hits: 516    Return