"Trademarks include any word, name, symbol, or device, or any combination, used, or intended to be used in commerce to identify and distinguish the goods of one manufacturer or seller from goods manufactured or sold by others, and to indicate the source of the goods. (United States Patent and Trademark Office)"It is a rather simple tenet of trademark law that a trademark cannot cover a functional product improvement.
So a device cannot cover a functional product improvement? This would implement the in the definition named "device" must not have any functions or at least no functional improving ones. Doesn´t a trademarked BMW car grill have any function? Besides the Spyderhole doesn´t need to improve anymore because the patent had expired. Since it has been trademarked it only needs to show "this is a Spyderco knife".
Then it must be also quirky to invent things that can be patented if no one else has had the idea before and after it´s patented no one else can use it for 14 to 20 years or so - how quirky.It is especially quirky to trademark a formerly patent protected feature.
What is wrong if the company that has used the round hole for many years and thus their knives are recognized by this round hole to be the ones from Spyderco with the well known high quality cannot let others reap the fruits of their long hard work? Instead it would be villainous to let other companies reap the fruits. Others can now use the hole as opening device as long as it is not round because ELUs then would think a knife with a round hole could only be a good Spyderco knife, not for instance a ching chang chong from melted trumpets.
If it would be so quirky to use trademarks, why then they are used for at least over 7000 years and governments support them by officially register them?
Best wishes,
JB