In reference to the patent: WO1997013970A1

Is this patent still active/ enforceable? I think this design is too similar to a detroit diesel 71 series uniflow engine. There are at least two other patents for a reverse uniflow engine, these are for spark-ignited versions while this patent is for compression ignition. I have a design for a reverse uniflow compression ignition engine which is significantly different. How can somebody get a patent for such a broad catagory that is already well known in prior art? Another question i have is shouldn't it be a requirement to build a prototype or do some type of computer modeling/ simulations? There is no proof that this concept even works, they have no experimental data to support their claims. I know from my research they are missing some very important details. In my opinion, a prototype or advanced computer modeling should be required for something as complicated as a internal combustion engine to support your claims. I also think there needs to be some type of effort to actually build and manufacture your invention. It seems very counter-productive and unfair to issue patents to companies or individuals who have no intention of ever building/ using their invention. As we know from some recent cases, some companies hoard patents and sue others who actually make use of these developments.


In the United States, your patent application must be enabling, meaning that somebody of ordinary skill in the art could practice the invention after reading the patent application. There is no requirement for a prototype to be submitted. A patent cannot issue if the underlying invention doesn't work, because patents can only issue for inventions that are useful -- although as a practical matter if an invention doesn't work, there is no harm to issuing a patent, since it would cover something that doesn't function, meaning that nobody would ever want to infringe it.

What is required is at least "constructive reduction to practice". For example, if you invented the GPS system in 1950, you could describe the system, including geosynchronous satellites, timing, triangulation, etc., and if you described it well enough that somebody skilled in the art could build it, your application should have resulted in a patent. This, despite the fact that you did not have the resources to actually launch the satellites, test the system, etc.

In the old days, a working model was required. This is no longer the case in the USA.


The document WO1997013970A1 is not a patent. It is a publication of an international patent application. There is no corresponding U.S. Patent.

More details on this international application are available on the WIPO Website.

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