Team Members:  Max Cossalter, Joe Hearn, Eric Ringsrud, and, Max Selna

Faculty Advisors:  Dr. Peter Schuster

QL+ Progam Manager:  Vanessa Salas

QL+ mechanical engineering students from Cal Poly San Luis Obispo were challenged to create an Adaptive Trailer Hitch for QL+ Challenger, Taylor Morris.  Taylor is a Navy Veteran and EOD Technician.  While serving in Afghanistan, Taylor encountered an improvised explosive device (IED) and lost parts of all four limbs.  Thanks to advancements in prosthetic technology Taylor still enjoys living an active lifestyle in Iowa. 

For this Challenge, the team took the process of hitching a trailer to a car and made it compatible for someone with only a single prosthetic hand.  This trailer hitching system will help Taylor switch between his multiple trailers with minimal need for outside assistance.

In order to identify what modifications needed to be made, we talked through the entire trailer hitching process with Taylor, noting which parts he found to be most difficult.  Through this conversation we found that the most problematic steps were rotating the triple ball hitch to the correct ball size, inserting the cotter pin through the hitch pin, activating the trailer tongue lever to secure or release the tow ball, connecting the trailer lights, and hooking up the safety chains.

While forming the solutions to these problems, the team made sure not to make any large modifications to important load-bearing components. This ensures that our system still complies with all safety standards put in place by the Society of Automotive Engineers (SAE) and the Department of Transportation (DOT).

For the hitch rotation process, the team modified a triple ball hitch so it can be pulled all the way out of the receiver, rotated, and pushed back in all with one hand while it is still supported.  Then, they eliminated the need for a small cotter pin by replacing it with a spring-loaded notched plate that secures the hitch pin and can be latched and un-latched with one hand. To help with opening and closing the tongue latch, where the trailer connects to the hitch ball, they made a lever that slides over the latch and gives extra leverage when opening and closing it.  For the electrical connection doors, they replaced the spring that holds the doors closed with magnets so the doors remain open.  Finally, for the safety chains, the team switched to certified hooks without a latch so they can be removed easier with one hand.

To confirm these processes can all be done with one prosthetic hand, the team made sure they could do them when only using one hand with an oven mitt on.  The team was excited to deliver this to Taylor and see how much easier it makes the process for him. They are hopeful that their simple and rugged design can last for many years on the roads of Iowa.