During his tenure as president of U.S. Terminals, Hilliard invented various items and ended up with 19 patents, one for the "Slip-Lock" Terminal which is a very clever design. The uniqueness of this design occurs after the insertion of the terminal in the chassis, the lug is fully inserted which expands the minor diameter of the bushing and securely locks the terminal into the hole.
As testimony from Hilliard's daughter, Peggy, Hilliard was always coming up with new designs and she used to hear him say, "Well, back to the drawing board" when things did not go according to his plans. And although drawing boards are now replaced by computer graphics, she said it was her dad's approach to always keep on trying, to never throw in the towel just because you are disappointed, but to keep up the effort until you get to where you want to go.