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).
Car spring flexibility and a strategy for supplying spare spring leaves to America.
Identifier | ExFiles\Box 16\7\ Scan339 | |
Date | 26th November 1930 | |
SG.{Arthur F. Sidgreaves - MD} FROM R.{Sir Henry Royce} C. to WOR.{Arthur Wormald - General Works Manager} HS.{Lord Ernest Hives - Chair} C. to BY.{R.W. Bailey - Chief Engineer} EP.{G. Eric Platford - Chief Quality Engineer} SPRINGING. X7410 R2/M26.11.30. X.7410. X.7772. X.3900. You can rest assured that there is no difference in the steel used in the American and British springs that will affect the riding qualities. Moreover the material and methods of manufacturing here have almost eliminated the faults of spring failure by breakage. The feature we have to decide in conjunction with springing is the degree of flexibility that it is practical to employ. I have suggested that we use 9" initial deflection for the back, and 4" for the front, but it may be that we shall move to go a little further than this, say 10" and 4.5", but the practical difficulties of not knowing the exact weight of the body, or conditions under which the car is usually run - high speed, low speed, fully loaded or lightly loaded - makes the exact rating that would give the greatest satisfaction difficult to arrive at, as we have 3 variables we have to adopt a practical compromise. As regards supplying cars to America I think it would be a mistake to cast them adrift (with no technical organisation) to make their own springs, and I should greatly regret if we induced them to do so. I think the difficulties can be met in a practical and inexpensive way somewhat as follows: (1) All the cars shall be sent here with the initial deflection as settled by HS.{Lord Ernest Hives - Chair} during his present visit, that is, somewhere between the limits suggested in this letter. (2) That the weights be estimated so that the springs are rather too flexible for the load than insufficiently flexible. (3) That a number of spare leaves for the springs and fittings be sent out so that the service arrangements can convert a spring fairly easily by fitting to the top plate belonging to the car another set of lower leaves. These leaves will be good stock and can be made so as to be used in several combinations, so that quite a small stock of leaves would provide a comparatively inexpensive and quick means of altering the stiffness of a spring and in case of breakage, repairs to springs. I hope it will be concluded that this practice can be adopted. R.{Sir Henry Royce} | ||