What happens when a patent expires?

At the end of a patent’s life, the patent expires and the inventor no longer has any rights in his invention.  Thus, anyone who wants to make or sell that invention is now free to do so. Generally, when the patent for a product expires, other companies will begin to offer comparative products at a lower price.  The most common example of this is with pharmaceutical drugs.  After the patent on a name brand drug expires, competitors will begin selling a “generic” version of that same drug, because the original pharmaceutical company no longer has the ability to protect the make-up of its brand name drug.