This is the average pull ball knife, made by George Schrade with thin plain (sometimes engraved) celluloid handles
After carefully removing the heads from the two pins with a rotary tool we can remove one of the handle slabs. Nothice the liner is notched, this is so it will flex out of the way when you close the blade and it has to bypass the part shown in the next photo
This is all that makes up a pull ball knife. a blade, one set of liners that is in reality one sheet of nickel plated brass that is bent over to form 2 sides instead of one. You also have the kick spring which also acts as a back spring in the open position. The end piece consists of a metal frame with a knife edge on the outfacing portion so when you close the blade it will slide off to one side or the other, the liner will flex out of the way and the blade snaps down underneath what we will call the "lock". The small coil spring is much like those found in Bic cigarette lighters, perhaps smaller in diameter but it keeps forward tension against the lock so there is resistance when you pull back on the ball, and it will spring back forward automatically upon releasing the ball, which is in this case is a small red die, most are balls of various colors, sometimes made to look like a billiards ball. The butt end of the kick spring also acts as a forward stop for the lock, so it doesn't move too far inward from the coil spring pressure.
The small coil spring gets compressed laterally in the knife between the vertical portion of the lock and a small vertical tab on the liner that is bent down from the top. It's a very simple design, with very few parts. They are easy to assemble, and cheap to make which made them great novelty giveaways for various companies who would order them in bulk with thier company's information inked on the handles. They are not, however well made. Their simplicity is also weakness, they normally have blade play, fire open moderately strong, but were prone to breakage, which makes them a fine friend of a knife repairman like myself.
Hope you found this interesting. I hadn't done a pictorial in a while and thought this would be something different you all may appreciate.
