I have. The key was not a cylinder, though. More of an offset wrench with small proprietary end.
Your certified and licensed elevator mechanic will have what is needed. Such persons are quite inexpensive when compared to lawsuits, repair bills, hospital co-pay, and/or funeral costs.
I have set sometimes people free from the elevator in our building.
Be VERY carefull.
We always let the elevator go to a floor manualy, then open the door manualy with the key.
In holland the key has a triangle inside (see photo).
My computer has slowed down to crawl and security is rejecting a lot
things,I have a private message for many months that I did not open,
because of the security thing. The elevator question was for safety
information,I understand the law and liability to help people.I guess
every state and country has laws about helping.
Thanks Again Guys