(click on pictures to enlarge)
Charles R. Keeran is one of the most influential innovators of mechanical pencils. He invented the Eversharp Pencil, as wells as dozens of other pencils, and he also was one of the early principals in Autopoint and later, in Dur-O-Lite.
These are marked "Keeran Pencil Keeran Products Co. Pats-Chicago-Pend." It is the only brand I know of that bears the prolific inventor's name.
The pencil is unique for its clip mounting, by which a z-clip was sandwiched under the top cap when the cap was press-fit into place. Keeran applied for this patent on October 3, 1925 and it was issued December 11, 1928 as Patent number 1,694,945. View patent here.