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).
Page discussing the principles and advantages of air springing for rear wheel suspension, with a comparative graph.
| Identifier | ExFiles\Box 178\1\ img195 | |
| Date | 28th August 1926 | |
| - 22 - Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}1/LG28.8.26. For the rear wheel suspension by coil springs, however, where independent wheel springing is most difficult, something on these lines may eventually materialize commercially. (b) Air springing. Recently, devices have been put on the market, notably by Messrs. Westinghouse, which employ compressed air as a means of absorbing road shocks. There is nothing new in this practice; compressed air having been used for years on big guns to deal with their recoil after discharge. The advantage of using a compressed air cylinder is that the force required to produce a given movement of the piston rapidly increases as the total piston movement increases. In other words, compressed air is equivalent to a variable rating spring. This is clearly demonstrated in the appended graph. From this it will be observed that for the first 1" deflection after normal loading the air spring would be equivalent to a normal spring of only about 20 lbs. rating, for the 4th inch to a normal spring of 400 lbs. rating. This graph is diagrammatical and the exact form of the air compression curve will vary with the speed of action of the suspension i.e. whether the compression is nearer isothermal or ababatic. Graph Text: AIR SUSPENSION. LOAD LBS. EQUIVALENT NORMAL SPRING. COMPRESSED AIR CYLINDER. INS. DEFLN FROM LOADED POSITION. contd. | ||