Well maybe some good research should be done. Similar concepts have expire dates for monopoly. For example Razors have generic replacements after "x" years. There is some loophole for this as to create a free market. I believe it is 5 years but I haven't looked.

Also when Cheyenne ( Mt.Derm let's be honest ) allowed others to use the cartridge lock in their grips ( Inkjecta and others ) or even screw adapters for the official hawk grip, they are creating a standard. Once you establish a product as a standard you must fairly license that patent to people.

The patent work is so so convoluted, the only thing that I know it doesn't serve is the consumer. Without choice in a market there is no evolution of products. The hawk carts still don't come with normal needles and they have been out for at least 6 years now.

Granted I am not a patent expert or a lawyer, so don't take this as fact. Only opinionated, observation.