When Charles King patented the Parker recessed hinge pin, or spherical recess around the pin, it was mostly for the purpose installation of the pin if I am not mistaken. I will have to double check the actual patent documents to make sure of that.
The original Parker hinge pin was a single piece was pressed in and the ends were not stepped. They eventually went to a two piece design that had stepped end and a slotted screw on the other separate end.
Some of the Fox pin guns I have seen have a slot on both ends of the pin, others have no slot on either side.
Last edited by B. Dudley; 07/11/14 09:44 AM.
