This patent covers the design of the Campagnolo Paris-Roubaix rod-gear system. The Campagnolo Paris-Roubaix was an 'improvement' on the Campagnolo Corsa - perhaps the most tedious gear system of all time.
The Campagnolo Corsa had two levers. One was to loosen the quick release of the rear wheel, and the other was to shift the chain onto a different sprocket, all while back-pedalling. The Campagnolo Paris-Roubaix improves on this by using the finest precision engineering to enable this task to be done with a single lever. The first eighth of a turn of this lever loosens the quick release - with the same lever then used to shift the chain. It is beautifully made, ingeniously designed and fantastically finished - but fundamentally unusable by anyone who cannot also walk on water and/or turn the aforementioned water into wine.