R&E Columbia/Improved Columbia lock

[Pschiffe]

Thanks for the info..I didn't think to search Google Books for advertisements. Seems that the actual patent is elusive..I would really like to see the inner workings of one. From what I can gather the original Columbia lock used a totally flat push key which acts on the tumblers all at once when inserted. The improved Columbia introduced a corrugated type keyway. As far as other changes I have no idea; I've yet to obtain an example of either of these cylinders. The keys seem to be the most common item to show up. An old R&E catalog I found on the internet from the late 1890's has illustrations showing that they once had an extensive line of Columbia locks--mortise locks, deadbolts, night latches, etc. Unfortunately no mention of cylinders or keys however.
From what I can tell cylinders are not threaded, but have some type of tapered edge which is wedged into place when the set screw is tightened. It's an interesting design that must have been quite short-lived considering the scarcity of any examples.

Perhaps R&E's answer to Yale's pin tumbler cylinder of the same era that was likely still under patent at the time?

Pete Schifferli