[paul cotter (OP)]

My attention has been drawn to US patent #us11411513b2. This is a granted patent for a free energy device. I thought this nonsense had been stopped after Robert Park kicked up a stink about patents that fall foul of the laws of physics being granted.

[Petrochemicals]

It's questionable the patents that are granted on the basis of being a new invention, I do not understand how Dyson did it given that he states the idea was given to him when he saw the dust seperation at a sawmill. I suppose the trick is to get a patent and then make someone else prove it invalid at the cost of all the legal fees.

[alancalverd]

You can't patent a principle. Nor, in the civilised (non-USA) world can you patent a discovery. All Dyson's patents are "a means of...." doing something, and a patent is only granted if the official examiner considers it to be truly original. So whilst centrifugal separation cannot be patented, the design and construction details of a particular device for extracting domestic dust from carpets can be.

The cost of invalidating a patent is negligible: you only have to show evidence of a prior disclosure, and the best evidence is another registered patent, which is in the public domain! The big cost is in defending a patent against unauthorised copying.

[alancalverd]

US patent #us11411513b2.

is not a free-energy device but

A method for providing electrical power to an electricity distribution grid by operation of a self-sustained nearly frictionless and near perpetual maglev generator started from an external power or battery source, said method comprising:

in other words, a very complicated flywheel.