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).
The testing and theory of Lovejoy shock absorbers.
| Identifier | ExFiles\Box 28\1\ Scan074 | |
| Date | 30th April 1928 | |
| Oy2-E-45026 4832 April 30, 1928 To: Mr. Nadin Mr. Bagnall Mr. Caswell Mr. Hulley Mr. Southern Mr. Beaver cc Mr. Hives From: Mr. Olley EXPERIMENTAL REPORT Lovejoy Shock Absorbers We have for the first time really found out what was the matter with our previous tests of Lovejoy shock absorbers on the front end. Mr. Lovejoy has a general theory that one should use the maximum possible spring setting in his instruments that the conditions of riding will allow. This is in order that there shall be a maximum insurance against the passengers being thrown to the roof. This may work out well on average stiff-sprung cars but it is certainly wrong on the Rolls-Royce. Consequently we have been using 100 lb. springs on the valves in both front and rear installations. This gives us 450 lbs. maximum pull on the strap in front (7" arm) and 315 lbs. at the rear (10" arm). Since the front axle complete only weighs 350 lbs. and the rear axle 650 lbs., these pulls are obviously too great. It should be explained that the shock absorbers we have been using for the last year or so, are essentially different from those we originally fitted. The earlier ones had two spring loaded valves, the 1st stage having a lighter setting than the 2nd stage. The later instruments are practically single valve instruments having only one spring loaded valve (the 2nd stage). The 1st stage spring-loaded valve has been replaced by a "cushioning" or "delay-action" valve which is similar to the delay action on a percussion-shell and causes the load to fall on the strap gradually and without shock. | ||