THIS paper reports work begun in 1935 at the instigation of the Murray Corp. of America. Methods used in studying the relations between the automobile seat cushion and its function in transporting passengers with greater comfort and less fatigue are described.
Constructed for this purpose was a piece of apparatus called the Universal Test Seat, whose dimensions were completely adjustable with arrangements to vary the distribution of the supporting pressure in any manner which seemed most comfortable to the passenger.
The authors describe tests made by use of this apparatus, present summaries of some of the results recorded and conclude that, to give the passenger the maximum comfort and least fatigue, the following mechanical objectives should be attained by the cushion:
To support the passenger over a large area to get the smallest unit pressure on the flesh;
To avoid variations in pressure from point to point over the supported area except those variations dictated by actual variations in the body of the passenger. (To obtain the surface contour and pressure distribution on the loaded cushion that is considered by the average passenger to be the most comfortable.)
By extending their analysis of the conditions required for static comfort, the authors believe that the objectives to be attained for dynamic comfort are:
To avoid large changes in pressure or forces acting on the body of the passenger with respect to time;
Especially to avoid high rates of change, with respect to time, of either the values or direction of pressures or forces acting on the human body.