I could never be a patent engineer...

I came across the description through the patent office for ball lock pins because someone mentioned it and I really was not sure what it was. When I read the description, it was much more confusing than looking at an actual picture of what a ball lock pin was. First the description:

A device for holding together two objects with aligned holes has a body formed with a passage centered on an axis, a tubular bolt axially displaceable in the passage and having a front end projecting from the body and a rear end, and a first spring braced between the bolt and the body for urging the bolt axially rearward relative to the body. A pin axially displaceable in the bolt is formed with a radially outwardly open recess having an angled front flank. At least one retaining element, normally a ball, is radially displaceable in the body front end between a retaining position projecting radially from the bolt and a retracted position recessed in the bolt and engaged in the recess. A second spring urges the pin axially rearward in the bolt and thereby urges the angled flank axially into engagement with the retaining element to press same outward into the retaining position.

Now the picture, and if you are like me, you said, "Oh...Now I know what that is."