1. Anti-Tip Bar for manual wheelchair
Nick Burjek
Andrew Dawson
Austin Dirks
Katie Gallup
Harrison Lamons

2. Problem Statement
Manual wheelchairs are typically equipped with anti-tip bars that prevent the wheelchair from tipping over backwards and injuring the user.
Decrease mobility of user
Most users remove bars
Higher risk on hills

3. Wheelies

4. Wheelies Uses of a Wheelie However, most users never learn this skill1
Pot holes
Soft or rough terrain
Curb Edges
Turning in place
Moving turns
However, most users never learn this skill1
Our system both allows wheelies and can be used as a teaching aid
Kirby, Lee. The Manual Wheelchair Wheelie: A review of our current understanding of an important motor skill. Disability and Rehabilitation: Assistive Technology. January 2006

5. Project Goals and Requirements
Develop a mechanical system that engages to prevent accidental tipping while preserving the mobility of the active user.
Inexpensive and lightweight
Maintain upright footprint
Be able to fold to fit into front seat of a car
Allow user to rest in a reclined position
Not inhibit any desired motion, wheelie
No added effort from user
**Be able to clear an 8in curb
**Be functional on an incline

6. Current Status
Met with project sponsor and brainstormed third iteration of design
New design addresses curb failure of previous prototype
Internal spring and pin
Solenoid activated stops
Uniball wheel
All will be designed in Pro-E for our sponsor

7. Methods Use a hinge based support system
Use square tubing which houses a spring or dashpot
As the bottom part of the hinged system moves upward, it will push on the inner tube which is connected to the spring an provides resistance
Pins will be activated by an electric solenoid device which will change the stopping position
There will be three stops: incline, normal, curb. The user will change the setting with a toggle switch located beneath the seat.

8. Results
Past Prototype achieves primary objective but can still be improved.
Holds the weight of user in a wheelie
Allows user to move side to side in wheelie
Enables user to go off 4 inch curb
Does not address curbs over 4 inches
Current design will enable user to clear 8 inch curb
Will have ability to let user switch settings

9. Re-Design

10. Future Work Meet with project sponsor to discuss redesign
Transfer redesign to Pro-E
Create a sturdy machined prototype
Time and resource permitting, work on a smart system incorporating solenoid angle sensors to actively engage when user over tips