Ace is a child that is 1-year-old, and cannot sit straight up on his own.
Ace cannot sit up straight without assistance. This makes tasks like going shopping difficult for the family. Ace must use his arms and plant them out to his side to keep from falling over. Because of this, he cannot sit up straight when he is seated in a shopping cart. The mother must place him in a car seat inside the shopping cart, taking up a large amount of room. She has also asked if the team could make the seat versatile enough to be placed in other seats, such as: restaurant high chairs, playground swings, and toy “carts.”
Ace’s mom currently has a mini pacer that works well for him. However, it is a device that is made to help him learn how to walk. It is far too bulky for a shopping cart, and is not designed for it. The seating inside the pacer works well, however there is no way to mount it with stability in a shopping cart seat. This is the only design that is even close to what Ace needs.
This is a folding bottom aluminum chair. The key features of this concept are the large foam pad that would wrap around Ace’s body, and the two small straps around the bottom that could be used for alternative mounting methods. Not pictured in this concept is an optional locking pin that will allow you to rigidly fix the seat relative to the back. Ideally, this could be constructed to less than 10 pounds, and allows for ease of movement.
This would be able to fold up, be versatile and easy to adjust. Both the back and seat are padded. The back would be able to adjust up and down with a spring pin. Instead of having something to mount it, it would be able to sit in the shopping cart seat. Attach to the back rest of the seat would be a strap that could be brought around to the front to wrap around Ace.
The top piece can be attached to the base via pins. The top can be adjusted to a different angle to allow for more comfort. Both top and bottom will be padded. The bottom will have a double hinge to allow it to go behind the back support for ease of carrying and storage. It will have a sliding pin underneath that will lock the seat in place. The base will have an arm that extends up with multiple holes for the top part to pin into.
Two aluminum bars connected by three shorter aluminum bars that has a hinge that lowers an aluminum plate. Coming off the two main aluminum bars are two straps that Velcro in the middle that fasten Ace to the chair. On the back of the chair are straps that can hook onto multiple surfaces.
The seat should be able to support Ace so that he can sit in the shopping cart seat. The team also concluded that it needed to be lightweight, and as small as possible. This is so Ace’s mom can easily haul the seat around to where she goes. The team also tried to incorporate the idea of being able to mount the seat in another locations besides a shopping cart seat.
After our first presentation, we looked over the feedback given by our peers and professor. We talked about some key points our peers had brought up during our presentation for Design #3. We took these into consideration and started on our design to present to Ace’s mom. After discussing with her, we came up with the following design.
We will figure that the maximum mass he could be while using this seat is approximately 15 kilograms. To find the maximum force that he would apply on the buckles, we will have take a short journey back to Dynamics. Recall that F = m * a. Let us assume that he is strapped into his toy cart and his sister is pushing him around. She starts running with him at a constant velocity 2 m/s and then stops quickly. We will assume that this deceleration took place over a time interval of one second. Let us assume the buckles experience one full G of acceleration. From our previous formula:
F = (15kg) * (9.81 m/s^2) = 147 N.
So obviously, this is nowhere near the 489 N needed to break the buckles.