Sat Aug 13, 2016 5:37 pm by Altashot
It's an old 8 line sargent knob tool.
It's to turn the little lock knob on an entrance knob set.
Bach then, when inside, you could only press in the little button without the tool.
Upon exiting, the little button popped out, thus unlocking the knob. You had to press it in again before closing the door to lock it.
Two little hole were in that button, like snake eyes screw. With the tool, in addition to pressing
the button in, it could also be turned to change the knob function to a store room function so that it would always be locked.
You can still find this function on newer knobs but in general, no tools is needed to turn the little lock button.
M.