Old Timer, as your name suggests you might be unfamiliar with this whole 'internet thing'. See, we have this tool called google. Your generation might call it a voodoo magic machine, mine calls it a search engine.
Just plug in any one of the sentences that Brian supplied you with from the abstract into this voodoo machine, and presto, you have the patent staring you right in the face.
"The examiner probably restricted his prior art search to previous patents" Prior art searches are not supposed to be limited to previous patents. It certainly is possible that the examiner did that, but my understanding is that doing so would not be adequate.
Of course, maybe it's so obvious to most people that it's never been written down and the patent examiner just happened to have been raised on cheese sandwiches instead of peanut butter and jelly.
Thats US patent 6004596, and the legalistic language used to describe a sandwich is hilarious. (Perimiter coplaner to surface... edible filling juxtaposed...). The claim says, make a sandwich, remove the crust, crimp the edge so the PB doesn't squeeze out. The USPTO shouldn't grant patents for such rubbish.
We have not seen enough of the patent to even know what is patented. Everything in a patent leading up to the claims is just fluff. Until you read the claims (and only the independent ones really matter) you realy cannot tell what the patent actually protects.
In the future it would be helpfull to our understanding if the patent number would be included in the article. That way we could easily read the whole patent for educational value.
The question of non-obviousness is subjective. It is assumed that a patent must be non-obvious to someone "ordinarily skilled in the art", which means people normally employed in the field, not experienced engineers who would come up with the same solution. In the case of sandwiches "ordinarily skilled in the art" would be any hungry 8-year old, so the patent application should have been deemed obvious. The examiner probably restricted his prior art search to previous patents. If the examiner had also turned to back issues of "Good housekeeping", I'm pretty sure he would have found something.