My brown Raleigh Twenty has the original Sturmey-Archer front hub, which has a few perculiarities when it comes to hubs.
1.) There are no lock-nuts.
2.) It matters which way you put the front wheel into the forks.
3.) Get it wrong, and you're in for a headache!
Sturmey-Archer, and I imagine a number of other British manufacturers did not have lock-nuts on their front hubs. Now this is the most important thing for you to remember.
ADJUSTABLE CONE GOES ON THE LEFT!
There is an adjustable and a non-adjustable cone.
- The non-adjustable cone screws in until it runs out of threads - (there is a shoulder on the axle for this). This cone is round - ie has no flats for cone wrenches.
- The adjustable cone has no lock-nut, so just screws in. This one has a pair of flats for a cone-wrench.
The front forks are key-holed - ie the axle won't just slip out, you need to spread them slight, as the cones have a shoulder which fits inside the round part of the fork end - a way of ensuring that a loose axle nut will not result in a front wheel falling out of the forks.