The trademark 'ESCALATOR' was registered (29-5-1900)

"The world's first moving-step machine...demonstrated at a Paris trade fair in 1900..."
The trademark was registered by Charles Seeberger, who worked for the Otis Elevator Company.
"The use of capital letters and inverted commas shows the word's special status." (Crystal)
BUT fifty years later (in _Haughton Elevator Co. v. Seeberger_), Otis lost the rights because the court ruled the word had become generic.
"A crucial piece of evidence was the way Otis itself was using it, in such advertisements as:
To thousands of building owners and managers, the Otis trademark
         means the utmost in safe, efficient economical elevator and
         escalator operation."