Substitution of scientific data obtained by experiment for the mere opinions long since prevailing about the respective values of arguments pro and con in regard to the interleaf friction of springs, the effectiveness of many leaves versus few leaves, the lubrication of springs and kindred subjects, was the objective of the author and the results he has secured since the start of the experimental work early in 1924 are set forth. Tests were conducted with springs having leaves varying in number from 1 to 14 and, in all cases, both when dry and when copiously lubricated with thin oil. All the variable factors were included during the progress of the experiments, the number of combinations possible being indicated by the fact that about 250 tests were made and more than 50 different springs were used.
After describing in detail the springs and the auxiliary equipment used and outlining the methods of procedure, the author presents tabular data and explanatory text relating to the effects of external friction, of fatigue, and of interleaf friction and lubrication. The effect of increasing the “nip” or tension between the leaves by making the longer leaves less curved and the shorter leaves more curved than usual was studied, as well as the subject of the “starting friction” of dry springs and the effects of rust and of tight shackles. Tests were made also to determine the number of spring movements per mile on the socalled “average” automobile, and these are discussed. In conclusion, deductions made from the data obtained are enumerated.