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).
Calculations and fitting procedures for front springs on various car models.
Identifier | ExFiles\Box 54\3\ Scan149 | |
Date | 3rd October 1924 | |
- 2 - BY/H.{Arthur M. Hanbury - Head Complaints} 3.10.24. added to each of the front springs over and above the calculated amount required, so that if a 1250 spring were required by calculation, the actual spring fitted would be 1250 plus 100 lbs = 1350 lbs. The 100 lbs is not a hard and fast issue. I am prepared to accept on light springs 80 lbs as being equivalent to 100, and on heavy springs, a slight increase above the 100; the figure of 100 is picked as being the nearest round figure as we order springs, to cover the issue. There are a certain number of cars, namely, the Olympia Cars and Paris Cars, which were fitted with the 25% stiffer springs. It is not proposed that these should be allowed to remain in position, but to replace them by springs as pointed out above. It will be remembered that these springs were fitted with taper packings to overcome the fact that they were turned out originally with an angle of 1 degree variation from the position square with the pivot. To overcome this, taper packings were fitted in such a manner that the seating for the spring was brought back to be exactly at right-angles with the axis of the pivot. In changing the springs, it will be discovered that from 1250 lbs upwards no packing will normally be required to keep the height of the frame right, but since we must have the correct inclination of the pivot, special inclined packings will be fitted to all cars fitted, that is, stiffer springs with the minimum thickness from 1200 onwards, the packing being the same dimensions as would be normally fitted with a 1200 lb spring. In order to maintain the tops of the frame parallel with the ground, looking at the chassis in front view, where a 1250 lb. spring is fitted on the offside, on the nearside a packing approximately twice as thick as would normally be required will be fitted under the 1200 lbs spring. The foregoing should clearly outline the spring proposals as discussed with Mr.Royce so that everybody concerned understands them. The foregoing is based upon the fact that finally it was decided that what was required Con. | ||