BibTeX:

@article{IJIRSTV3I10083,
     title={Design and Fabrication of Multiutility Wheelchair},
     author={Sandip S. Bag, Prem D. Lohe, Harshal K. Hajare, A. N. Madne and Ajinkya S. Hande},
     journal={International Journal for Innovative Research in Science & Technology},
     volume={3},
     number={10},
     pages={182--188},
     year={},
     url={http://www.ijirst.org/articles/IJIRSTV3I10083.pdf},
     publisher={IJIRST (International Journal for Innovative Research in Science & Technology)},
}

In this project we propose a design of wheelchair whose backrest and a footrest can be controlled through a switch by the patient which will convert the wheel chair into a stretcher. This helps the patient to rest without getting shifted to a bed. This will also eliminates the efforts of assistant required for handling of handicap patients by providing an arrangement of desk with wheelchair. We went through a number of designs before arriving on the final design. Our requirement of motion could be achieved either with the help of belt and pulley arrangement or through gear transmission. Belt and pulley arrangement was avoided because of the high speed reduction and the factors like slip and weight involved. The purpose of locking also could not be addressed easily in this arrangement. The idea of spur gear transmission was also eliminated because the requirement of high torque, self-locking could not be satisfied. Also, this arrangement demanded two separate motors. Considering the above mentioned shortcomings, Worm and Worm wheel arrangement was selected. The advantage of this drive was it provided self-locking, since the motion is transmitted only from the worm to the worm wheel and not the other way round. The arrangement was compact too. Chain and sprocket arrangement has been used for transmitting the motion provided by the motor through Worm and Worm wheel arrangement. Another advantage is, it provides high speed reduction.

Chain, sprocket, Stretcher, wheel chair, Worm and worm wheel