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).
Scheme 1830 for a parallel control system, including specifications for radius rods and front springs.
| Identifier | WestWitteringFiles\L\2July1924-September1924\ Scan111 | |
| Date | 12th August 1924 | |
| TO BY.{R.W. Bailey - Chief Engineer} FROM DA.{Bernard Day - Chassis Design} Copy to - CJ. HS.{Lord Ernest Hives - Chair} SECRET. DA{Bernard Day - Chassis Design}2/M12.8.24. E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. 11. re. PARALLEL CONTROL. 18/240 We send herewith N. scheme 1830. shewing the arrangement of the radius rod and rear bracket of front spring for parallel control. The radius rods are the same as those previously sent you as far as the joints are concerned the length only being different. The only alteration to the frame tie rods is the slightly different position of the front eye, and an additional feature on the front king post. The front axle has the radius rod ball ends in the position recently telegraphed to you, namely, 30.25" centres, and is otherwise unaltered. The big alteration is the front springs which it will be seen are 45" long, .4" normal camber with a 2.75 maximum bump. We should like Derby to do these springs. It will be noticed that the height of the spring top plate above the pad will become very important in this scheme, as any variation in the distance between the radius rod and the top plate of the spring will upset the parallelism of the control. We have shewn a spring 2.8" thick. In some cases a thicker spring than this may be used which will have the effect of increasing the twist in the front axle. Whether this is important or not can only be decided by experiment. The depth of spring we shew is proportional to the maximum depth now used having regard to the fact that the springs are 45" instead of 42". It frequently happens that the springs on cars are not the same depth on either side, and this will have to be corrected by packing. We are hoping that all EAC.2. cars will have this parallel control fitted, but we want the Experimental Dept. to say that the slight twisting of the axle which is unavoidable with the arrangement shewn is not permanently detrimental to the axle. DA.{Bernard Day - Chassis Design} | ||