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 – Higher risk of tipping

3. Background Target audience is new lifetime wheelchair users – High demand for freedom and mobility – Chairs need higher performance characteristics Wheelchair users will nearly always remove anti-tip bars found on back of wheelchair – Found to be obtrusive – Gets in the way of wheelies, turning, uneven terrain changes, etc. Anti-Tip Mechanism

4. 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 – No added effort from user

5. Use a hinge based support system with spring Serves 2 functions – Provides resistance to user while achieving their balancing point – Acts as a stop to prevent user from tipping backwards Methods Current example of anti-tip system

6. Uniball wheel Stopping Wedge Spring Design Spring

7. Method

8. Current Status Completed building of one prototype Performed feasibility testing Redesign of first prototype – Wedge incorporation – Uniball wheel – Smaller Hinge – Spring centered – Improved general construction of prototype

9. Current Demonstration

10. Results Feasibility of new prototype tested in demonstration Shown to hold up weight of normal human Able to rotate during wheelie Adds resistance to user while reaching balance point More aesthetically pleasing

11. Future Work Test new prototype on different terrain, curbs, wheelies, normal everyday functions Transfer current prototype design to Pro-E Create a sturdy, finalized, machined prototype Time and resource permitting, work on a smart system incorporating solenoid angle sensors to actively engage when user tips