There are tens of thousands of patents on the airplane and all parts of it.
No; Twitter notably has not filed for any patents.
No, patents cannot be obtained for any naturally occurring substance.
Richard Feynman
He is dead and doesn't own any property, let alone patents.
Either they have licenses for any necessary patents, their valves do not infringe any of those patents (utility or design), or the owners of those patents don't care enough to find infringers and challenge the unauthorized use.
The United States Patent and Trademark Office has a website giving great detail on the steps to create a patent, including the necessary forms. http://www.uspto.gov/patents/process/index.jsp
A propeller airplane is, simply put, any airplane which uses a propeller for propulsion.
Probably not. While the president has some knowledge of patent law (he is a former attorney), there is no evidence that he has invented anything, nor have we seen any reports that he holds any patents himself.
An airplane's cockpit is the pilots' station in the airplane.
You can search for information on patents by simply usng the Google patent search at www.google.com/patents.
California historically files for more patents than any other state; in 2010, California applied for nearly four times as many patents as its closest competitors, New York and Texas.
99,220, including utility patents, plant patents, design patents, and reissues.