Trap for a mouse
US Patent No. 6,655,077
Issued December 2, 2003

Build a better mouse trap and the world will beat a path to your door!  Here is a better mouse trap, at least according to the disclosure contained in the patent.  It would be easy enough to poke fun at the Patent Office by saying that “the mouse trap was patented in 2003,” but we could even go one better than that.  The last patent issued with the words “mouse trap” in the title issued in May of 2007.  This patent, US Patent No. 7,216,457, is to a pyramid shaped mouse trap, which is of a different kind than this far more traditional mouse trap we are discussing here, but it is still nevertheless a mouse trap. 

All of this is still really only half the story.  A search of the Patent Office online database shows that sine 1976 some 44 patents have been granted with the term “mouse trap” in the title.  The oldest of these, US Patent No. 3,992,802 even points out that there have been many attempts at mouse traps, most of which include some kind of spring mechanism.  So, mouse traps are certainly well known, the question is whether this particular mouse trap is different enough from previous mouse traps to deserve the mantle of patent protection. 

I am not a mouse trap expert, but the picture sure looks like every other mouse trap I have ever seen.  The broadest claim in this patent is written in what is called Jepson format, which is quite dangerous.  The preamble to a Jepson claim is admitted as being prior art.  Admitting anything is prior art is never wise, but with this invention one could hardly argue that a standard mouse trap is prior art.  Nevertheless, Jespon claims should usually be avoided.  They are characterized by the transition phrase “said improvement comprising.”  Everything before that phrase is admitted to be prior art.