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).
Design challenges of leaf springs to accommodate a wide variety of customer loads and body types.
| Identifier | ExFiles\Box 67a\1\ scan0057 | |
| Date | 6th January 1926 | |
| - 4 - comparison showing that to step down on the range like CWB. suggested, we should necessarily put up the stress in the thin leaf spring of the present type and range to approximately the position, so far as stress is concerned, that resulted in fractures on the thick leaf springs. With reference to the final paragraph of Item 7. the requirements of our customers are so wide and varied it is quite impossible, in my opinion, to have a standardized set of springs to suit each type of body, which is what the proposal put forward amounts to. Some customers will have a big body and only have two people riding about in it at any time. Other people will have a big body, notably Sir Robert Hadfield, and will so load it up that the springs are practically bumping, and when such a car is driven over bad roads, complaints will undoubtedly arise due to the excessive bumping of the buffers on the axle. This last result would be a natural effect, because our present range of springs are designed and produced with a constant camber in the 'free' position. If a light load, namely, two to three passengers, is treated as the full load, then on such occasions as the car carries the full complement of passengers for which it is built, it will mean that the axle clearance has been reduced very seriously, since the full clearance is only arrived at on the allowance for a load of two passengers, and the further four with luggage that are added would have to be accomodated by cutting down what has always been considered to be a necessary clearance between the buffer and the axle. In conclusion, I am definitely of the opinion that the remedy for the springing is for Sales, when treating with a customer, to find out definitely from the customer the number of passengers which are likely to be using the car under normal conditions. This is what we have always tried to spring for, and it is what R.{Sir Henry Royce} recommends, as it results in the best compromise for the all-round conditions, but in a case where 90% of the running was done with two passengers, we would consider it was correct to spring for this abnormal condition, and run the risk of bumping on the axle Con. | ||