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).
Performance, dimensions, and issues of 19-EX Governor Shock Dampers.
| Identifier | ExFiles\Box 182\M18\ img071 | |
| Date | 14th February 1933 | |
| Mr. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} W. Hancock, c/o Hotel de France, Chateauroux, Indre, FRANCE. To GWH.{George W. Hancock - Head Chateauroux} from Hs{Lord Ernest Hives - Chair}/Les.{Ivan A. Leslie} Hs{Lord Ernest Hives - Chair}/Les.1/KT.14.2.33. 19-EX GOVERNOR SHOCK DAMPERS. Thank you for your letters dated the 10th and 11th inst. We presume that the figures you have given for the loads of the dampers at various road speeds are static loads. On these type of dampers the static loads do not mean very much, owing to the large viscosity effect in the dampers. For example a damper set at a static load of 70 lbs. gives a load of 330 lbs. at 1.5 ft/sec. axle movement. This accounts for the fact that it is difficult to hit the buffers on Peregrine over bad bumps. The dimensions on your sketch of the bellows are approximately correct. There should be up to .070" between the bellows and the valve spring when no oil pressure is supplied from the governor unit. The total movement of the bellows is .100". We intend to increase this movement when we have had more experience with this type of shock dampers. With regard to your remarks about the road springs, being too high rating for a continental type chassis, we are very pleased to hear that you are sufficiently impressed with these new shock dampers, to consider them capable of taking part of the duty which is now taken by the high rating road springs. We are inclined to agree that it may be possible, but we should have to gain considerably more experience with these dampers first. Since you have been in France we have burst three damper casings, due to the internal oil pressure. Until we have had much more experience with these dampers in the Expl. Dept. and on production, we cannot expect to gain much more from the governor controlled shock damper than to dispense with the Hartfords on the continental chassis. The shock damper casings as fitted to 19-EX are liable to burst if the loads are set too high. Before 19-EX returns to France, it will be fitted with the | ||