The doorknob was invented in 1878 by Osbourn Dorsey when he filed a patent for an internal mechanism that latched doors shut. If Dorsey's knob was on the left side of a door, it unlatched a metal bar on the right side of the door.Continue Reading
The metal rod latched into a hole in the door frame. Homeowners accessed the connection in the frame by unscrewing a small metal cover.
Before doorknobs, homeowners secured doors by using a latch string that looped around a bar to keep strangers out. In ancient times, people raised and lowered bars to secure doors so that people could not get inside.Learn more about Inventions
The first light bulb patent was filed in 1841 by Frederick DeMoleyns. American J. W. Starr patented his design in 1845. By 1880, American Thomas Edison had created his own light bulb using carbonized bamboo as the filament.Full Answer >
The helicopter as a practical flying machine was invented in 1931 with a patent application by Igor Sikorsky. The patent was accepted by the U.S. government in 1935, and Sikorsky's helicopter first flew in Connecticut on Sept. 14, 1939.Full Answer >
Richard Arkwright and John Kay of Great Britain invented the water frame in the late 1760s, and Arkwright applied for a patent in 1769. The patented spinning machine twisted 96 strands of yarn simultaneously.Full Answer >
Elias Howe is credited with receiving the first patent for a modern, practical sewing machine on Sept. 10, 1846. Records show that patents were applied for before this date; the earliest was on July 17, 1790 by Thomas Saint.Full Answer >