I have been having a discussion with a fellow collector about the Crosley porcelain tube socket and the U.S. patent process and how it works. Powel Crosley first started advertising his new porcelain tube socket in a July 1921 QST advertisement shown below. All of the Crosley porcelain tube sockets I own, whether brown or white in radios or not, seem to have patent pending molded on the top of the socket. The question is about the patent process and how it works and what patent pending means in this case. If the patent wasn't filed until Dec. 7th, 1921 does that mean all of the sockets with patent pending on them were produced after that date? Or did the patent process actually start in May or June when the socket was actually designed? It is interesting to note that the porcelain socket was no longer used by the time the patent was actually granted.

Thanks for your help.
Alan Larsen

July 1921 QST Crosley advertisement.


Patent application showing that the patent was filed Dec. 7th, 1921 and granted Dec. 14th, 1926

"Pat pending" as far as I know means that an application has been filed. I've seen instances where no patent was ever issued. Just possibly the "pat pending" on the socket refers to an application that was never granted, not to the patent that actually was.

M.J. O'FALLON toilet bowls, Patent Pending were found all around in old house rooms rented out to D. U. students. Probably still flushing away. Why not?

Other than a very severe physical blow or severe corrosion or immersion, there is seriously not all that much can happen for a ceramic socket. The contacts are another issue as are the johnny bolts, wax seals, and other unmentionables.

Hmm. Odd that it took that long, with changes in radio techology seemingly weekly in the 20's. Perhaps it was the configuration as it looks to me like the bakelite versions. Perhaps he found they could get the molded bakelites cheaper than ceramic, with fewer defective ones, etc. He was always trying to keep costs to a minimum at that time to try to undersell other makers, I understand. An exotic archane question with perhaps no answer available, as everyone involved is gone that might have an idea about it. I can't think of any other ceramic parts in the inexpensive Crosleys of that era. Perhaps the ceramic molding supplier had problems keeping tolerances. Anything.