From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Comparison of tensile and compressive stresses in different leaf spring configurations, with notes on the effects of shot blasting.
| Identifier | ExFiles\Box 110\3\ scan0037 | |
| Date | 13th January 1941 | |
| Rm{William Robotham - Chief Engineer}/GB.8/ET.13.1.41 - 2 - There are nine leaves in the spring. In spite of this the stresses are rather high. Some comparisons are given below. The Myth spring is a grooved Woodhead and the tensile and compressive stresses are given. The stresses given for the 1000 lb. and 1200 lb. grooved Woodhead springs are tensile. The compressive stresses which are higher are not given. In the 1050 lb. Firth spring, tensile and compressive stresses are equal. | Leaf No. | M Y T H.{Arthur M. Hanbury - Head Complaints} | | | | VAUXHALL 10 | | FIRTH 50" 1050 lbs. | | 1000lb grooved Woodhead | | 1200lb grooved Woodhead | | |---|---|---|---|---|---|---|---|---|---|---|---|---| | | Spring flat | | Bump | | Flat | Bump | Flat | Bump | Flat | Bump | Flat | Bump | | | Tension | Compres-sion | Tension | Compres-sion | | | | | | | | | | 1 | 62,500 | 74,800 | 117,000 | 140,000 | 57,000 | 120,000 | 42,600 | 80,450 | 53,500 | 97,900 | 57,000 | 90,600 | | 2 | 73,400 | 87,300 | 123,000 | 146,500 | 76,500 | 132,000 | 40,400 | 78,250 | 67,100 | 111,500 | 67,300 | 100,900 | | 3 | 73,400 | 87,300 | 123,000 | 146,500 | 76,500 | 132,000 | 66,700 | 104,550 | 74,500 | 118,900 | 74,000 | 107,600 | | 4 | 73,400 | 87,300 | 123,000 | 146,500 | 76,500 | 132,000 | 74,100 | 111,950 | 74,500 | 118,900 | 74,000 | 107,600 | | 5 | 73,400 | 87,300 | 123,000 | 146,500 | 76,500 | 132,000 | 86,600 | 124,450 | 74,500 | 118,900 | 74,000 | 107,600 | | 6 | 80,300 | 96,500 | 124,800 | 150,000 | 88,000 | 139,000 | 95,300 | 133,150 | 74,500 | 118,900 | 74,000 | 107,600 | | 7 | 80,300 | 96,500 | 124,800 | 150,000 | 88,000 | 139,000 | 95,300 | 133,150 | 76,400 | 116,900 | 67,200 | 97,700 | | 8 | 80,300 | 96,500 | 124,800 | 150,000 | 88,000 | 139,000 | 95,300 | 133,150 | 76,400 | 116,900 | 84,000 | 114,500 | | 9 | 80,300 | 96,500 | 124,800 | 150,000 | | | 95,300 | 133,150 | | | 84,000 | 114,500 | The leaves of the Myth spring are to be shot blast on the tension side at the rate of 20 sq. inches of surface every minute. This should give a useful increase in spring life. Shot blasting reduces the free radius of spring leaves. The free radii of the leaves in the Myth spring given in the table are those required after shot blasting. The quench radii will be less. | ||