At least, I THINK I invented it. (mostly because nobody else has probably ever wanted it).
I'm knitting doll clothes, for my very old dolls. Two of the dolls are very breakable, and this is the first time I've made anything for them. Up till now I've only knit for my teddy bear - and I discovered I had an "issue" with the fragility factor of the doll.
I like to knit on circular needles (knit flat). No big needles flopping around when I'm working on such small pieces, and there's the advantage of being able to slip the work onto the flexible cord and hold it around the doll for fitting, because of course I don't have exact patterns - sort of make them up as I go along.
My issue is - you know how "springy" circ's are - well, every time I held the wip against the doll, no matter how careful I tried to be, those needles kept clanking against her legs, and when I was totally focussed on checking the fit (and unfortunately only have 2 hands), I thought it was even possible one of those needles could sproiinggg up and smack her on the nose or her teeth - it was giving me the creeps. She might've been wearing a really old dress all these years, but her face and body are in perfect condition, and would I ever be upset if I chipped her, trying to make a new outfit. So I stopped the project and worked on the problem instead.
Knowing what stocking stitch loves to do - tada - needle covers. I just have to slip an elastic band on for extra security if I need to. NOW I can go back to my project.