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).
Letter to Luvax Ltd. regarding tests on their NP.3 shock absorbers for the 25 HP car.
| Identifier | ExFiles\Box 28\1\ Scan261 | |
| Date | 11th August 1931 | |
| 8832. Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}3/AD. August 11th, 1931. Messrs. Luvax Ltd. Warple Way, Acton, London, W.3. For the attention of Mr. Pitt. Dear Sirs, We have now carried out a few tests on the Luvax shock absorbers which you submitted to us as being suitable for our 25 HP. car. Type NP.3. We attach herewith indicator diagrams taken from this shock absorber. Diagrams 1, 2, 3, and 4 show the effectiveness of the shock absorber when set to the load supplied by you. We should explain that from tests we have carried out measuring the axle movement loaded for the frame, we find a movement of 4" at the ball pin with a frequency of about 70 per minute which corresponds to the frequency of the road springs, whereas a ball movement of 1" with a frequency of about 450 complete strokes per minute, corresponds to the control required to prevent the axle dithering when driving fast on any main road surface. We therefore require the shock absorber to be effective over its range in order to give good results on the road. Diagrams 1 and 2 show that over the 4" stroke the shock absorber does not get on the job as soon as the reversal of axle load commences. We consider that this is undesirable. | ||