This popped up un Facebook. The first electric drill that I ever used was this one of these with a 1/4” chuck about 75 years ago.
The black circle at the base of the chuck was an eccentric that did the final tightening using an Allen wrench. The grip on the drill bit was excellent but somehow this chuck fell out of favor.
The black circle at the base of the chuck was an eccentric that did the final tightening using an Allen wrench. The grip on the drill bit was excellent but somehow this chuck fell out of favor.