After I finished sketching my idea I began working on turning the handle. I used Ash because it is a durable wood commonly used for making tool handles. Then I mounted the aluminum shaft collar that I bought on the handle's stem.
Next, I inserted the shaft of the hollow chisel into the handle and tightened the screw.
I gave the tool a test run and, once I was convinced it works well, I contacted Rockler's product development team. I asked them if they were interested in my new tool in exchange for a royalty agreement. Some woodworking companies such as Rockler and Lee Valley will consider independent innovator ideas for their future products. If the idea seems practical and novel, the company will offer the inventor a few percentages from the proceeds. Fortunately, Rockler expressed interest. It took them a year or so to finalized the design. They introduced a new shape and clamping mechanism that uses a set screw, much like the one on the mortiser machine, to clamp the chisel shaft into the handle.
If you come up with a good idea for a new tool, hardware, etc, and want to have it made and receive royalties for it, consider approaching a reputable tool/hardware manufacturer. Don't expect the proceeds to get your child through college or fund a new yacht, but rest assured that the satisfaction (and the occasional check) that you will receive from time to time is worth the effort. Plus, you will be able to call yourself "an inventor" when you are introduced to people during a dinner party or to the guy sitting next to you on the plane.. (flying coach, obviously).