Proto Drill, is made to be adjustable for close quarters.   From the defense industry in WWII so I have read.   The factories soon found that the bulky electric drills of the time just couldn't be used everywhere.  Handle is hollow for bit storage.  Only one I had seen and grabbed it.  Paid for it too. 

Yeah, those multi-flex hand drills are cool!

I found two - one was missing the hollow handle. The later (complete) one cost me $4. (Don't hate me!)

I have one somewhere in the crates of old tools.

Looks pretty versatile all right.

NICE!!

This is the 1943  Ira Clawson patent
(https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/pdfs/US2310759.pdf)
I always imagined that the examples marked "Jo Line" (Jo Mfg Co.) predate those with Proto markings (Proto no. 370). Is that true? What was the relationship between Jo and Proto? Here are the two side by side:



I passed on one last year at Spanky's antique store in Hastings, Nebraska. Maybe it's still there...

Looks great :)