Our goal is to design a Safety Bed for a five-year-old boy with Down Syndrome and Autism. A Safety Bed will allow the parents to sleep without worry, and get the child out of their bed, while keeping the kid safe.
The child likes to roam about and is quite wild overall. He needs to be supervised at all waking hours in order to keep him out of dangerous situations. Since the parents do not have any way to contain him in a safe manner, they have resorted to having him sleep in their bed. The kid also only sleeps for four hours a night, thus the parents never get proper sleep. All together, having a safe, secure location that the kid can sleep in will drastically improve both the parents, and the child’s well being.
At this point, we began by researching the general safety bed concepts on the market, and determining how it would be best to construct one. We had yet to meet with the family, therefore the research could not focus on the specific needs. We determined that there are generally a few kinds of safety bed on the market. There are rigid ones with full wooden or metal frames, more tent like safety beds with a soft tarp like structure, and then some oversized crib style beds in case less protection against escape is needed.
Left Bed :
Right Bed:
We selected Concept Design 2 but implemented different modifications to better accommodate the child’s specific needs.
Two-level wooden structure with a strong rectangular frame
Four main legs provide stability and support
Top surface has slats to allow airflow and reduce weight
Mesh on all sides to create a safe enclosure and prevent the child from roaming away
Bottom level has a solid platform for storage or support
Side cross-bracing improves strength and stability
Simple design makes it easy to build and assemble
Modifications were made to better meet the child’s needs
Designed to be stable, durable, and practical for use
This was a rather simple calculation of the beds total mass with a more realistic density value than Solidworks uses. We simply took the volume, multiplied it by the density, and found the mass to be ~370 pounds.
This one came from a desire to not see the bed fall down when the kid is climbing upon it. We got the center of mass of the bed from Solidworks, and added a mass five inches from the top edge of the bed, roughly where the kid’s center of mass may be. We then calculated how large the mass would need to be in order for the bed to tip, which occurs when the center of mass is no longer above the support base. This occurred at greater than 1600 pounds, so it is safe to say that the bed will not tip.
Lastly, we found the reaction forces of the legs if the kid is jumping in bed, to make sure it does not get too large. We were able to use 2D simplification due to the symmetrical nature of the supports, leaving a 2D beam with three supports. This was statically indeterminate, but included in the Perdue Beam Tables. From there, we found the reactions are well within reason for the wood used.
