Background:

 

While the concept and design for Levaté are incredibly applicable to wheelchair users (see the Levaté Wheelchair Lift design description), the actual implementation of requiring a user to purchase an expensive, bulky, loud pump to pressurize his air tank at the end of the day seemed implausible or, at the very least, unattractive to potential customers. Not only is there the possibility for users to forget to pressurize their air tanks when they get home, but there is also the strong chance that users cannot afford and do not want the additional expense of both money and space that a pump would require.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Design Considerations:

 

• How far do manual wheelchair users travel on a daily basis? How many lifts would they expect to want in a day?

 

 

 

 

 

 

 

 

 

 

 

 

So What? - Wheelchair users travel around 1.7-3.0 miles per day and need about 14 lifts from Levaté per day.

 

• How much force do wheelchair users exert on standard wheelchair ramps?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

So What? - Wheelchair users exert well over 25 lbf ascending a standard wheelchair ramp.

 

 

• How much additional force would a theoretical piston-based repressurization design require of the user?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

So What? - Utilizing multiple, offset pistons results in much more air with only slightly more force (approx. 2.74 lbf).

 

 

• How well do experimental measurements of additional required force agree with the theoretical predictions?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

So What? - Experimental results confirm wheelchair users would experience only about 3.0-3.5 lbf of extra exertion.

 

 

Conclusion: The additional force required of wheelchair users is not prohibitive to the successful operation of the accessory.