Tricycle-Based Hand-Powered Wheelchair

A tricycle-based wheelchair is designed to enable the user to exert less energy than required by a standard wheelchair while ensuring safety and comfort. The Tricycle-Based Hand-Powered Wheelchair allows persons with physical disabilities to exert less energy during travel, enjoy outdoor activities, and exercise upper body muscles. Since the wheelchair is a hand-powered tricycle, the user must have sufficient upper body strength to power it. The Tricycle-Based Hand-Powered Wheelchair can be used outdoors on level surfaces, and is able to go 15 degrees uphill.

This tricycle-based wheelchair is fully mechanically operated. The chassis of this design originally came from a bicycle. Three 26-inch bicycle wheels, linkages, sprockets, and a chain are incorporated. The seat slides forward and back via a sliding mechanism and also may be adjusted up and down. An electrical jack is attached on the bottom of the chair to operate the seat adjustment. An important part of the design was calculating the gear ratio, which can help the rider operate the wheelchair while exerting less energy. The lever gear has 15 teeth and the two-speed gear has 30 and 45 teeth. The speed for a 1:2 gear ratio is 2.14 mph and the speed for a 1:3 gear ratio is 1.43 mph. Thus, the 1:3 gear ratios uses less energy but travels one third less than the 1:2 ratio, which is useful for going uphill.