An approach for experimental modification of the existing Tricycle

used by physically challenged people

PRESENTED BY:-1.ABHIJIT SINHA (DG/ME/B/01/15) 2. ABHIJIT BANIK (DG/ME/B/06/15) 3. GAURAB PAL (DG/ME/B/14/15) 4. BISWAJIT SARKAR (DG/ME/B/25/15) 5. BIDHAN SARKAR (DG/ME/B/34/15)

Introduction: People with physical disabilities in developing countries face many challenges integrating into everyday life. If these people cannot obtain a wheelchair they are sometimes forced to stay trapped in their home or use crawling as their only means of transportation. Immobility adversely affects the lives of disabled people by, for example, making it near impossible to attend school, participate in the community or earn an income.

History of tricycle:- A three-wheeled wheelchair was built in 1655 or

1680 by a disabled German man, Stephan Farffler.

In 1789, two French inventors developed a three wheeled vehicle, powered by pedals; they called it the tricycle.

In 1818, British inventor Denis Johnson patented his approach to designing tricycles.

In 1876, James Starley developed the Coventry Lever Tricycle.

In 1877, Starley developed a new vehicle he called the Coventry Rotary, which was "one of the first rotary chain drive tricycles.

Objective:- The objectives of developing such a tricycle are mentioned below:-

To reduce the human effort used for riding the tricycle.

To give space for carrying goods. To provide Comfortable sitting arrangement. Easy turning mechanism.

Working principle of existing tricycle: In this tricycle, the power source is generally manual which drives all the machinery elements comprising of chain , sprocket, brake etc. however the same tricycle also can be driven by suitable motor & power can be delivered from one place to another place by chain sprocket arrangement. The existing structure of tricycle most commonly consists of two big sprockets(driver element), two small sprockets(driven element) and two chains for transmitting the power from driver to driven.

Flow diagram of transmission system

Construction details:-

Our concept of tricycle mainly consists of 3 wheel 2 chains 4 sprockets 1 footrest 2 hand paddle a metallic structure

Proposed modified tricycle

Components with details:- 1)Wheels:-

There are three wheels which help in movement of the tricycle. In our concept tricycle we would like to adopt the 20X1.75 types of 3 wheels. The distance between the front wheel and rare wheel is approximately 1920 mm. The distance between the two front wheels i.e. the width of tricycle is approx. 610 mm.

Fig: Wheel - structure

Chains and sprocket:-

The tricycle has two types of sprocket (one big sprocket & one small sprocket) & chain for transmitting the power to the wheel. The diameter of the small sprocket is 38mm. & the diameter of the big sprocket is 101mm.

Fig: Small Sprocket without Chain Fig: Big Sprocket with Chain

Seating arrangement:- The seats have two parts. One is top portion

and another is bottom portion. The measurement are shown in the fig. and a human load of 80 kg approximately has been taken into consideration.

Fig: seating arrangement

Footrest:- There is a footrest for placing the legs. The height of the footrest from the datum is 140mm.

Fig: Footrest

Steering Mechanism:- In this modified model, for the purpose of transmitting the

power two (2) numbers independent chain drives have been connected with two (2) respective front wheels. When two (2) hand paddles are allowed to rotate equally (approximately with equal r.p.m) than the whole tricycle would move in the forward direction. If the left side paddle is allowed to rotate keeping the right side paddle fixed than the tricycle would take turn in right side direction & in the same way turning in the left side direction can be achieved by rotating the right side paddle only.

Structure:- The metallic structure supports all the

elements of the tricycle as shown in the fig: 2.1. A special arrangement has been made to provide 360° rotation of the single back wheel. The total height of the tricycle is 1920 mm.

Comparison with existing tricycle and proposed modified tricycle: Existing Tri-cycle Proposed tri-cycle

1.Wheel position One wheel is in the front & two wheels are in back side. 2. Steering mechanism For steering, a handle stick or bar is used which is able to rotate. 3. Power transmission Power transmitted on one of the two back wheels. 4. Extra facilities No extra facilities are available.

1.Wheel position Two wheels are in front & one wheel is in back side.2. Steering mechanism For steering two hand paddles are used & difference in r.p.m between them is used for taking turn3. Power transmission Power transmitted on both front wheels.4. Extra facilities Extra facilities in form of a basket &water bottle holder would be provided

Approximate price list of different parts of proposed tri-cycle

Future Scope:- In the modified try cycle the solar cell can be used for the power supply. In recent days Nano technology is used to increase the efficiency of the solar cell & by this technology the weight of the solar cell is also reduced appreciably along with increasing the efficiency. So we can use this type of solar cell in the modified try cycle for power supply as its efficiency is high & it increases the weight of the tricycle very little.

Thank you