View source for 1/24/2011:Rear Derailleur for a Bicycle Patent - Stulc

Patent 4575365: Rear Derailleur for a Bicycle, March 1986

This patent improves the typical rear derailleur for a bicycle by adding a mechanism that makes the bike less noisy when shifting gears and causes less wear for the rear cassette, chain, and derailleur. It is a new invention because it makes use of the tension in the chain to hold the skewed portion of the chain straight, thus reducing noise. This is interesting to me because I have done a lot of work on bicycles and enjoy understanding how they work. It is a completely mechanical system that works very well in its purpose. I find it interesting to see how even an idea that had been around for years, like the rear derailleur, can still be improved upon and then patented. I found this patent on google patents by searching for the bike component company Shimano. This patent was developed for Shimano Industrial Company.

[http://www.google.com/patents?id=7O8zAAAAEBAJ&zoom=4&pg=PA1#v=onepage&q&f=false]Patent 4575365, Rear Derailleur for a Bicycle