I'm designing a test barrel rig for a project that I've been working on and was considering what I would need for a trigger. I don't have a milling machine, so I'm a bit limited on what I can do. I did a bit of a web search on trigger design and looked at all the images on Google Images, but all seemed more complicated than I really needed for this project. I originally wanted to use one of the cheaper electrically operated solenoids, but I just don't think they have enough power to set off a primer.
So, as I got to thinking about the ones that I saw on web, I noticed that all of them basically had a trigger that pivoted from the *top* and then had at least one other piece to change the rotation from how the trigger what was necessary to cock / release the firing pin. There just seemed like there should be a way with less parts. As I thought about it a bit, I came up with the idea of pivoting the trigger from the bottom, not from the top. The trigger gets pulled back, rotating on the bottom of the trigger, which then pulls the firing pin / open bolt back with the top of the trigger. This continues until the catch is not able to maintain contact with the firing pin / open bolt anymore and at this point, the compressed energy of the spring attached to the firing pin / open bolt is released, causing it to go forward and strike the primer.
Something like this:
This is just a quick-and-dirty sketch... I show it as an open bolt since it's quicker to draw and for a single shot test barrel device, an open bolt is acceptable. With the dimensions and angles that I have here, it would not retract the open bolt far enough to allow you room to load a new round, but that could be changed by increasing the height of the tab that catches on the bottom of the open bolt and changing the cutout angle at the front of the trigger. I tried a 10 degree angle and that obviously was not enough. I switched it to a 23 degree angle on this drawing and it's still not right, but getting close. But, it's good enough for illustration purposes for the discussion at hand...
Has anyone ever seen a firearm with a bottom pivoting trigger? Surely I'm not the first person to come up with this idea...