The Fischer Patent

On my chess960 blog (see the sidebar for a link) I'm fond of using the phrase 'Fischer's greatest invention' to describe Chess960/FRC. I'm certain that 99.9% of competent chess players would have a different opinion. Here's one serious alternative.

Chess Patents (m-w.com)
'Patent no. 4884255: Digital Chess ('Fischer') Clock'

More info can be found on US4884255A - Digital chess clock - Google Patents (patents.google.com). For example:-

Abstract: A game timing apparatus and method for simultaneously timing events for two players is disclosed. The method involves presetting a pair of clocks for respective initial time periods, starting one of the clocks to time a first player's move, simultaneously stopping one clock and starting the other, and incrementing or decrementing each of the clocks by a time interval once for each move or a group of moves. [...]

For any skeptics who doubt that Fischer was capable of obtaining this patent, note the additional info against it:-

• 1988-08-05: Application filed by Fischer Robert J
• 1989-11-28: Application granted

I'd never encountered Google Patents before. What's new in chess inventions since I created the 'Chess Patents' page in 2007?