Long preparatory lead-in for a simple question.
With respect to patents,
Assume a feature on a product or line of products is patented by the original designer/maker/company.
XX years down the road, AFTER the original patent has expired, if someone wanted to use that feature in their work, would the 'new' maker/manufacturer need to get permission to use the feature from the original designer/maker/company or (or current holder of the name)?
The most obvious example of this situation of which I can think would be with the patent Western was granted in 1932ish for the double tang construction. The patent expired before Western sold out to Coleman who sold off the Western name to Camillus in 1984 who declared bankruptcy and sold off all assets in 2007.
If someone was to want to make double-tanged knives, would they need to legally or honorably have to get permission from someone?
I'm sure there are many other examples out there, some even dealing with sheaths.