Just as a quick introduction, I have been making my own recurve and long bows for many years and also black power rifles (including making and rifling the barrels). I have also made a few simple crossbows along the way. I recently got the urge to do a serious crossbow build. So glad I found this site! Most of the crossbow building stuff on the net is junk. But there is nice work and interesting ideas going on here.
So I have to say up front I am not normal. I never just build a kit or a copy of an existing design like a rational person. I always have to design my own. In this case I am starting with the trigger assembly. There are a lot of usable designs out there but I have a couple of goals in mind. I want it to have a very light pull and at the same time be ultra-safe. (I know that sounds like a contradiction) Something like a set trigger on a BP rifle but one that is easily put back to safe. So here is what I have come up with so far. I added a hammer. The overhead claw is the same as a conventional setup and the latch is also similar except that it takes a 90 degree bend up at the pivot pin. If the hammer was allowed to strike the latch directly, it would be unsafe because any inadvertent blow to the back of the hammer would cause it to discharge. So I incorporated an inertia transfer bar. The transfer bar is just a bit too short to make contact with the latch with the hammer down. With the hammer up, a spring pushes the transfer bar out just a bit so that the hammer will strike it when it falls. That will cause the transfer bar to fly forward and inertia will cause it to strike the vertical arm of the latch. The Latch will then rotate and release the nut.
I built a wood mock up to test the action and work out the 3D fit issues.
Here is a picture:
And here is a video showing its operation;
I welcome any comments even if they point out flaws. Better to know before I cut metal!