This seems like something I should have figured out by now. The smaller bar that is attached to the latch bolt and moves independently of it, on a door knob latch...what does it do? I've been googling for awhile and can't even find out what it's called, let alone it's purpose. I don't have an extra one to take apart right now so I thought I'd just ask here. Also, when the door is shut should that part be extended through the latch plate with the bolt or not? Thanks for any info.