Optimum seat pan and back-rest parameters for a comfortable tractor seat

An experimental set up was fabricated to measure the pressure distribution on the seat pan and back-rest of a tractor seat. Experiments were conducted with four different seat pans having radius of curvatures of 60, 75, 90 an d infinity cm, four backrests with radius of curvatures of 30, 60, 90 and i nfinity cm, and three back-rest inclinations of 0 degrees, 5 degrees and 10 degrees on representative Indian tractor operators. The subjective assessm ent of perceived comfort at the seat-operator interface was also recorded. Experiments were conducted in a randomized block design and the data obtain ed were analysed using suitable computer packages. Results indicate that al l the parameters, namely seat pan, back-rest profile curvatures and the bac k-rest angle of inclination, affect the pressure distribution. It is conclu ded that a seat pan with radius of curvature 75 cm, back-rest with radius o f curvature 30 cm and back-rest inclination of 10 degrees are the most suit able parameters for Indian tractor operators.