Dave said that this detail was copied from a similar fixing on the clevis' from the York engine.
Yes it isn't the normal installation for a spit pin but I think the intent is to prevent the pin from rotating and wearing the hole in the clevis. This is a pretty elegant solution to that problem. The other end of the pivot pin is flush with the clevis and the screw & split pin also prevent the pivot pin from moving sideways out of the clevis. The part count is the same as with a split pin on both ends of the pivot pin and the part count is the same. I think this makes for a cleaner installation aesthetically.
Ken,
All very well and makes sense but it does violate the principle behind a cotter pin and/or safety wire which arrangements cannot vibrate loose. It wouldn't be allowed on and airplane or a race car or racing motorcycle.
I think it's elegant but on an aesthetic level only. If it were in a high vibration and control critical location, it wouldn't be a good idea.
I have this fun cartoon idea where the cotter pin has it's screw which has it's own cotter pin which has it's screw . . . . . . .
Mike
If you think you are too small to make a difference, try sleeping with a mosquito.
Dalai Lama
When I went through (mostly) Otter's 120 year old engine, I found the holes for the eccentric rod clevises well worn in the bronze Stephenson link casting... and the pins were completely shot. I bored the holes in the link out to 1/2" and turned and inserted Delrin bushings and made hardened pins to fit. The clevis ends completely hide the Delrin, and there's not even a hint of play or sound.