I've been researching on how to renew an expired patent, and all I get for results are maintenance fees for patents filed on or after December 12th 1980. I am hoping someone would have an idea or an answer or even a good source for me to look into it.
A patent has a term of twenty years from the date of its first filing. It should be noted that once these twenty years are over, a patent is no longer in force.
However, there are certain scenarios where a patent has "lapsed" or "ceased to have effect" or “expired” even before its 20 years term, due to non-payment of annuity/maintenance fee associated with it. Upon failing to pay that fee, a patent may lapse or cease to have effect.
In some countries, a lapsed patent can be reinstated/restored by paying an additional fee plus the maintenance fee, and reasoning that delay or nonpayment of the maintenance fee within the prescribed period was unintentional.
The Indian Patent Act also has similar provision for restoration of lapsed patents. The following link can be referred for more details on the Indian Patent Act's provision for restoration of a lapsed patent. http://www.invntree.com/blogs/options-restore-lapsed-patents-india
No, unfortunately once a patent has expired, that's the end of it.
The philosophy behind patenting something is that in exchange for sharing your invention with the world, the government will give you the ability to stop others from making it for those twenty years. So if they let you extend it more and more, that wouldn't fit to that particularly well.
Your best bet is to come up with a viable improvement and re-file, although of course that isn't realy the same thing.
If a patent is no longer in force due to its owner unintentionally missing a maintenance payment the owner can petition for its revival. If it expired at the end of its term it is done. If you are a third party looking to take over a lapsed patent that you had nothing to do with, then it is a very big no.
Unlike trademarks, patents are not renewable. Once the patent has expired or the has ended then that's it. But as what Matthew said, the best thing to do is to think of any improvement on the patent and file it again.