Osbourn Dorsey was an African-American man who invented the doorknob and doorstop in December of 1878. He successfully obtained a patent for his work in the same year. Because of the time in which he lived and the fact that he was African-American, very little is known about his life. Historians still wonder if the man was born free or if he was a freed slave.Know More
Historians do not know where Dorsey lived or what other inventions he created, if any. Historians do not even know what Dorsey did for a living. Most of the information about Dorsey and his inventions comes from his patent application.
Before Dorsey’s invention people closed and secured doors in a variety of ways. Many people used some type of latch to keep doors closed, whereas others used leather straps as handles. Even after the doorknob was invented it took years for people to embrace them fully and begin installing them on the doors in their homes.
Other important African-American inventors include Alexander Miles, who invented the elevator a few years before Dorsey invented the doorknob. In 1923, Garrett Morgan invented the traffic light. In 1960, inventor extraordinaire Fredrick M. Jones invented the thermostat control.Learn more about Inventions
When you do not see any screws on the doorknob, press a flat screwdriver into the thin slot on its shank, and pull the knob to remove it. Use the screwdriver to pry the metal trim from lockset, and access the hidden screws holding it in place.Full Answer >
A doorknob is considered a wheel and axle because it has a wheel portion, the knob, and an axle, the rod in the door, that turn on the same axis. In instances such as a doorknob, a wheel and axle can also be considered a type of lever.Full Answer >
Tim Dorsey's novels belong in publication order, beginning with "Florida Roadkill," published in 1999, and ending with "Shark Skin Suite" as of 2015. They are not intended to be read in linear order because the series contains back stories and flashbacks.Full Answer >
The first telescope was invented in 1608 in the Netherlands. Dutch eyeglass maker Hans Lippershey applied for a patent on a telescope several weeks before Jacob Metius, also a maker of optical instruments. Because he applied sooner, Lippershey is credited with inventing the first telescope.Full Answer >