Allen brand ratchet

In 1910 William G. Allen  patented a setscrew with an internal (socket) hex for tightening the screw, this became known as the Allen screw and the Allen Manufacturing company was set up in 1913 to produce the setscrews and accompanying hex keys.  Although Mr. Allen left the company shortly thereafter, the company prospered, branching out into regular wrenches and related tool sets. Somewhere along the way they became part of the Armstrong tool company which was swallowed up by Danaher in 1994. In 2012, Danaher sold their tool business and it became part of Apex Tool Group. 

This ratchet has the Danaher era logo so must have been made post 1995. 

datamp.org