Innovation. Its been a part of Kelley since 1953 when we invented the worlds first counterbalanced dock leveler. Since then, Kelley innovation has produced a comprehensive line of dock products, including many industr......Innovation. Its been a part of Kelley since 1953 when we invented the worlds first counterbalanced dock leveler. Since then, Kelley innovation has produced a comprehensive line of dock products, including many industry firsts. The next time you see the familiar green triangle, remember what it means... At Kelley, were First. And built to last.