Ok, this is something I have to believe somebody else has thought of, but I haven’t seen it, so I thought I would ask readers if they have, and if not, to put it forward.
Everybody has a socket wrench set. The wrench heads tend to come with a square hole in the top, typically 1/2” or 3/8” square, into which the square drive from the ratchet inserts. There are sometimes spring-locks to keep it in place.
However, when you have a nut that’s going on a long bolt, you can’t use a standard socket as the bolt won’t fit inside. So you need to get a “deep socket” head, which may be able to handle the long bolt. Yes, you shouldn’t have such long bolts, and perhaps should saw off the end, but in reality this happens in places where that’s not easy or worthwhile. You can’t have just a deep socket set, because that’s bigger and heavier to carry around, and may not fit in various confined spaces.
The problem is that the drive is a solid square pin inside the wrench head. If the drive were able to grasp the wrench head from the outside, like a standard nut, then you could have an “extender” which could make any of your sockets a deep socket. To do this, the top of the wrench head would not be round, as it typically is, but hexagonal. In fact, your “extender” could simply be another, larger wrench from the set which fits around this hex head. Or you could have a small number of extenders in various sizes, and in extreme cases, multiple extenders. The extenders might do well to also have spring locks like the current drives do, to hold elements in place for you.
One could also have a thin hex shell embedded in the socket, the way lockable lug-nuts do, but that would not be as strong. Of course, one could try to do a whole new type of driver which is hollow, but the existing drivers are so well standardized now (there are not even metric versions) that I doubt it would get much adoption.
While we’re on this topic, here’s another idea. Organizing socket wrenches in a case is a pain. They often fall out and it’s hard to put them all back in the right place. I’ve seen colour coded sockets (fairly good) and laser etched numbers that are easier to read, and cases that try to bind the wrenches so they won’t fall out as easily. Realizing that the outside does not have to be round, I wonder if we could have patterns at the nut-end of the wrench that make it easy to slot how they go into their case. Perhaps just a couple of bumps or notches, so that no wrench can go in the wrong slot, even a slot for the wrench that is just a bit bigger.
