Wheelchair Canopy

  • The wheelchair canopy protects anyone that needs a wheelchair from rain, snow, and other elements. It folds back to stay out of the way when not in use. It has a ratchet mechanism that allows the user to position it however far up or down they need, and its modular design allows it to be quickly attached to any standard wheelchair.

    When we spoke to a person who uses a wheelchair, one of the issues we heard about was weather, and how to avoid it. Since two hands are needed for full control of a wheelchair, holding an umbrella is very inconvenient. Our project frees both hands without increasing the width profile of the wheelchair, so it can still fit in an urban environment. The project would enable any wheelchair user to get through the weather without inconveniencing them or complicating their movement.

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    At the beginning of this studio, we talked to someone who uses a wheelchair and asked what problems they face in using it. Due to the unfortunate lack of innovation in the wheelchair industry, there are many.

    Our group wanted to create a multi-purpose, easy-to-use canopy shield for protection from the elements. Originally, we also wanted to integrate this with a Pico-Projector, which would allow the user to have their own personal movie theater or display useful information. This was the impetus for the idea of a rotating rain canopy, which would double as a heads-up display. After some negative feedback, we scrapped the HUD. The rotating canopy remained because we thought it was a stronger idea, and it also got positive reception from someone who uses a wheelchair.

    The first major design problem we encountered in this project was the hinge. Our dilemma stemmed from the need for a mechanism that both allowed it to rotate freely when needed, but also be stationary when the user wasn't actively rotating it. At first, we researched the type of hinge used in baby strollers, which eventually became our inspiration.

    We needed to figure out how many positions the pieces actually had to lock in place at. We constructed an all-cardboard mockup to get a sense for the size of the pieces and how many positions we'd need. We decided that 15˚ intervals made a lot of sense since they'd give us a total of 12 positions in a full rotation.

    Next, we needed a mechanism to lock the hinge pieces in place when they weren’t in motion. The first hinge model was comprised of two ridged discs that locked in with each other. We experimented with different numbers of ridges, but found that our original number worked best. 24 ridges (12 up and 12 down) with 15˚ intervals worked extremely well in our simulations. The ridges turned out to be too large, so we sized them down and reduced the thickness profile. We also added four holes to the disc for attachment, but decided to omit them since they made the piece look ugly.

    After that, we had the idea to add a third, double-sided disc in the center with a spring gently compressing the three. We also added a slot in one of the top pieces for a wooden dowel. We also designed a piece to slide around the wooden dowel and wheelchair back. The piece has two parts per side, which screw together.

    Then we experimented with mechanical simulations of three discs. Once we were happy with the way they worked and fit we tried to print them. Because of some issues with our 3D printer, we were unable to successfully make the center disc. Unfortunately, this issue persisted until the end of our project.

    Another major challenge was finding a material to join the two hinges and support the fabric. We were going to use steel coil, but it broke too easily. Luckily, we found a thin material called spring steel, which was better at holding its shape reliably.

    We had to add small slots to all three hinge pieces to accommodate the spring steel. Testing the fit led us to find that it worked, so we started to shift our attention to the actual canopy. We decided we wanted three fabric panels to completely encompass the user. After we learned how to iron and sew, we made the first prototype out of a dark red fabric. This was surprisingly difficult due to the curvature of the panels. We decided to reduce the number of panels to two, with one being larger. This way it was easier to sew, but still large enough to offer decent protection. Following this prototype’s completion, we found a water-repellent, translucent material for the final canopy. We sewed the final canopy fabric together using this material. This model was much neater and better-shaped, since we were much more familiar with what we were doing.

    At this point we decided that wood was not the best material for the rods on either side. We opted for stylish blue aluminum rods. Not only are they stronger than wood and water-resistant, they look much more modern. We adjusted the base attachment pieces and the slot in the hinge to fit these rods, then printed the pieces out. Again, we were unable to print the center pieces simply due to issues with the printer. However, we were able to put the rest of the project together and test it!