No. Once the patent is gone, it's gone.
Patents can only go so far its the copyright and trademarks that does the rest once Patents expire and doesnt get renewed (considering China blatantly doesnt give a damn for all things considered) its open to be purchased by trolls
ideally speaking you can use patent trolling as a get rich quick scheme
I see, so right now no one is holding the patents over the design?
The Goulet listing mentions that the transparent (non-actylic) models can be eyedroppered. Does anyone know what size the O-ring you install should be? I tried one of the O-rings that I use on my Preppies, and it stuck out too far and blocked the cap. Should I just try it with silicone grease and no O-ring?
I don't see any limitations of making this an eyedropper pen since it has no metal parts.
Maybe you should consult with the Customer Service at Goulet, I've heard that their CS is excellent.
Also I wouldn't recommend going only with a silicone grease. People have had success using the O-Ring only but I believe using silicone grease only have a greater risk of leakage.