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

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

Wheelies

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

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

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

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.

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

Re-Design

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