Stethoscope
Prior to the Reiger stethoscope, there were bell-type stethoscopes and diaphragm-type stethoscopes, but no one had combined the two. This invention was the first to use a valve that allowed a physician to switch between the bell and diaphragm.
View Patent
Stethoscope
Prior to the Reiger stethoscope, there were bell-type stethoscopes and diaphragm-type stethoscopes, but no one had combined the two. This invention was the first to use a valve that allowed a physician to switch between the bell and diaphragm.
View Patent
Chinese Typewriter
In the early 1900s it was completely impractical to produce a typewriter with the tens of thousands of Chinese characters needed for ordinary writing. The Yutang invention solved the problem by overprinting portions of the characters, sufficient to form about 90,000 characters.
View Patent
Calculating Machine
Burroughs patented the first practical adding and listing machine in 1885. This was his second patent, focusing on independence between movement of the indicators and movement of the keys.
View Patent
Suspension
This patent didn’t claim the concept of suspension bridges, but instead the use of wooden sticks in the foundation. In practice such “sticks” measured 12 – 15 inches thick, and 40 feet long.
View Patent
Steamroller
Improvement In Tractor Engines – Steam powered tractors were already well known in 1876. The invention here was a driver engageable, dis-engageable worm shaft that drove the back wheels.
View Patent
Barbed Wire
Addition of spurs to twisted fences was originally conceived to prevent cattle from breaking through wire fences. The invention was to twist the spurs around only a single strand of a twisted pair to prevent the spurs from sliding in the bell and diaphragm.
View Patent
Accordion
Modern accordions typically have 2 – 4 reed ranks on the treble side and 3 – 5 reed ranks on the bass side. The Razzaboni accordion tried to reduce the number of reeds by allowing a given reed to be alternatively played as either a pure note reed or as an octave reed.
View Patent