FOLDING THREEWHEEL WHEELCHAIR:

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FOLDING THREE-WHEEL WHEELCHAIR Concept
Presentation
Amanda Maguire, Neeharika Bhartiya, Andrea
Blakemore, Rebecca Hung
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CURRENT DESIGN
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PROPOSED DESIGN OPTIONS
1 Single Side
Use x-brace like normal folding 4-wheeled
chair Attach castor on one bar coming out of
side of frame Front rod swings into folded seat
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PROPOSED DESIGN OPTIONS
2 Detachable Castor Wheel
Disconnect front castor wheel from one of the
front rods Flip two front rods (one with castor
wheel attached) up like footrests
Front rods then fold up into seat Seat folds
in like a folding 4-wheeled chair Seat would
probably also have x-brace to enable to fold in
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PROPOSED DESIGN OPTIONS
3 L-shaped Bracket
Modified x-brace Center rod comes directly out
of center of bracket Front rod folds under
according to last years design Force on seat
will hold back rest in tension and lock bracket
open
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PROPOSED DESIGN OPTIONS
4 Pancake
Cloth armrests for very active users for
whom armrests get in the way (like Abdullah)
Backrest folds down into seat Front rod folds
down into seat Remove wheels and attach to top
and bottom of folded frame
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PROPOSED DESIGN OPTIONS
5 Truss and Pivot
Back of seat like a truss Could separate bars
to collapse seat in Bar that seat rests on
pivots Shown configuration for when being used
as seat Would then rotate 90 so that bar no
longer supports seat and seat could be folded in
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PROPOSED DESIGN OPTIONS
6 V-shaped
Design taken from walker design 2 bars in
v-shape make up frame (we added bar in back to
support seat frame) To fold in, push two sides
together Back bar has joint in center to fold in
or out
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FEATURES OF MERIT
Most Important Features (Given Weight of
2) Overall Cost Based on number of total
parts, number of custom parts, number of bicycle
parts, and manufacturing steps Robustness/Durabil
ity Sturdiness, not too many moving parts,
designed to resist wear Ease of Use Is it easy
for user to fold or instruct others how to
fold Length of Life How long will chair be
able to be used? Safety/Stability Tipping, does
it stay open when in use?
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FEATURES OF MERIT (CONTINUED)
Folded Size How small is the final, folded size
of the chair? Functionality/Effectiveness How
well does it serve its purpose? Weight How
heavy is the chair? Modularity/Adaptability
Applied to other chairs/use of existing
frame Maintenance How much needs to be
done/how easy is it to maintain? Complexity/Eleg
ance Are all parts necessary? KISS
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FEATURES OF MERIT (CONTINUED)
Availability of Materials Can materials be
easily found in areas we are designing for
(locally available)? Bicycle part vs. custom
parts Reliability Will chair consistently
work? Use in Different Environments Can it be
used in all terrains? Ease of Design How easy
is it designers (aka us) to prototype and
actually make the final concept? User
Acceptability like the design/want to buy the
chair for way it looks Loose Parts How many
parts need to be removed to fold?
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EVALUATION OF DESIGNS
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FINAL DESIGN
L-SHAPED BRACKET
Was chosen because it performed very well in
several categories Folded Size
Functionality/Effectiveness Ease of Use
Complexity/Elegance Also did not perform
exceptionally poor in any categories
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COUNTERMEASURE
If the L-shaped bracket design does not work out
for any reason, we will move ahead with the
Pancake design When evaluating our different
designs, this option scored second best, only to
the L bracket Not ideal because it has loose
parts, and has a fair degree of difficulty in
disassembly As a backup, it is ideal because it
does not require all that much
alteration to current design, but would still
achieve capacity to fold
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NEXT STEPS
Week of April 13th Most Critical Module
Presentation Detailed Analysis on Final Design
Concept Perform Benchmark Experiments Make
Decisions on Materials to Use for
Prototype Build the MCM! what is our MCM?
FOLDING MECHANISM we need to calculate
strength, stiffness, and if it can keep front
wheel vertical
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ANY QUESTIONS?