It has been a while but here is Doug Daye with part five of Black inventors and innovators.
Air Conditioning Unit
Accomplished inventor Fredrich M. Jones was led to research refrigeration techniques in order to store blood serum and medications during World War II. He created an air conditioning unit to be used in military field hospitals as well as a refrigerator to be used in military field kitchens. Jones was also awarded 60 other patents for various inventions in his lifetime which included, window air conditioning units and ice cream making machines. He was the first African American elected into the American Society of Refrigeration Engineers and was also a consultant for the U.S. Department of Defense and the U.S. Bureau of Standards. Jones received his patent for the air conditioning unit on July 12, 1942. (Thanks to Jones, we have a way to cool off in the Texas summer heat!!!)
Photo Print Wash
Clatonia Joaquin Dorticus created an improved photographic print wash machine which he received his patent for on April 23, 1895. In the process of photo developing, Dorticus created a method that would eliminate over washing that would make the photograph too soft and stick to the sides of the tank. His design included an automatic register and automatic water shut off to conserve water. Also, a removable false bottom was used on the washer, in order to protect the prints and negatives from chemicals and sediment that remained in the tank. His design went on to be cited in five other patents for photographic film and print washers filed over the next 100 years!
On December 10, 1878, Osbourn Dorsey patented the design for the first modern doorknob at sixteen years old! Not much is known about his life other than that he was possibly born into slavery in 1862 but was freed before his first birthday. Most of the information on Dorsey and his inventions comes from examining his patents. Prior to his invention, people would open and close doors by using leather straps or latches which were not the most effective. Dorsey’s “door holding device” as he called it, allowed for a more effective way to secure a door. It was also the first doorknob design fit for manufacturing. While the general public was slow to adopt the doorknob, it eventually became a significant device in public and private spaces that is still used to this day!