My mom has these on her garage doors and it’s only a matter of time before I have to do something with them, so I did a bit of research. This is a good video. It shows a cutaway inside the end bracket showing the pawl that holds the spring tension (skip to 1:30).
I haven’t read this anywhere and I’d have to experiment with it to confirm this, but here’s my interpretation of how it works. I suspect that there is an internal spring that pushes the pawl forward onto the teeth inside the end bracket. If that spring were to break, the pawl might disengage and the door might drop. If that happened I think that the purpose of the small spring visible in your picture is to force the “outer latch” that you’re pointing to in your photo into the different set of shaft teeth visible outside the end bracket, stopping the door.
I might be wrong about all this, though. It’s much harder to figure something out without getting your hands on it.
Chris
I haven’t read this anywhere and I’d have to experiment with it to confirm this, but here’s my interpretation of how it works. I suspect that there is an internal spring that pushes the pawl forward onto the teeth inside the end bracket. If that spring were to break, the pawl might disengage and the door might drop. If that happened I think that the purpose of the small spring visible in your picture is to force the “outer latch” that you’re pointing to in your photo into the different set of shaft teeth visible outside the end bracket, stopping the door.
I might be wrong about all this, though. It’s much harder to figure something out without getting your hands on it.
Chris
