Backpack Lever Arm SystemBy Ma, Lu; Shah, Raj; Kryzman, Nahum, Enderle, John; NSF 2008 Engineering Senior Design Projects to Aid Persons With Disabilities, pp. 182-183
Publication Date: 2010
Description of a motorized lever arm system designed to aid in retrieving a bag from the back of a wheelchair. The system was developed by engineering students at the University of Connecticut at Storrs for a client with cerebral palsy. The design makes use of the client’s functional right arm. The backpack lever arm system consists of 3 limbs, two of which are moved by Servo motors. Limb 1 is clamped to the back of the client’s wheelchair. The limbs are connected via L-shaped hinges. When the switch located on the system’s controller attached with a Velcro strap to the user’s arm is turned on, the motors rotate the lever arm. The limbs rotate about the hinges in alternating clockwise and counterclockwise directions to bring the backpack, which is attached to Limb 3, as close to the client’s midline as possible. In their final positions, Limb 1 remains attached to the back of the chair, Limb 2 is directly above the right arm rest, and Limb 3 is in front of the user with the backpack attached to it. Turning the switch to the off position reverses the rotational motions of Limbs 2 and 3 to bring the lever arm to a collapsible position at the back of the wheelchair. Costs of parts and materials for the project were about 750 dollars.
Published by: Creative Learning Press, Inc. (Website:http://www.creativelearningpress.com)
Link to text: http://nsf-pad.bme.uconn.edu/2008/Chapter%2010,%20University%20of%20Connecticut.pdf