I look out the window of my building from my cubicle and see a little sliver of Grant Park on Chicago's lake front to the south. On the other side of Grant Park lies Soldier's Field and McCormick Place.
McCormick Place is named after "Colonel" Robert McCormick, staunch anti FDR Republican and owner of the Chicago Tribune. Colonel McCormick was one of the heirs of the fortune made by Cyrus McCormick selling the McCormick reaper.
The reaper was patented. Obed Hussey had patented a reaper as well. They fought in court over the patents, but both were sold for many years under the separate patents. Obed ended up with the "most" ownership of the design, but they were not exactly alike.
Think about the old saying: "Build a better mouse trap, and the world will beat a path to your door."
As a matter of fact, Massey Ferguson, John Deere, Alice Chalmers and many others made reapers, harvesters, tillers, bailers and many more patented farm equipment. Each performed the same functions, but each did it in a slightly different way. They each were building better mouse traps, not the same one.
The US constitution supports patents in section 8:
"To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries."
The purpose must be to promote, not hinder, the "Progress of Science" and "useful Arts". Temporary, and exclusive, rights "to their respective" creations are granted. Not all creations that perform the same function are protected against, but the ones that do it the way you made it work. If someone else makes a golf ball that is different than your golf ball, they get their patent and you get yours. In this way the 'useful Arts' are promoted. "Build a better golf ball and the golfers will beat a path to your door" has become "and the lawyers will beat a path to the Court."
We have come almost 180 (degrees) in patent law from the simple language of the Constitution. Patents should protect an individual, specific design, and those very close to that specific design. However, they should not hinder novel designs. That would be against what the constitution authorizes. Also they must be time limited, or innovation will be destroyed. Manufacturers often tweak products and file for a new patents, then use the current broad, not specific, reach of patent law to hinder innovative competition.
The current interpretation of patent, and copyright, law clearly is in opposition to the clear language of the constitution. We arrived at where we are through multiple small steps, small interpretations of the law that have us now applying laws that grant broad reaching and almost never ending rights. The current state of the law, as interpreted through the lens of many years of collective case law, hinders innovation, competition and free enterprise.