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).
Outlining four separate experiments proposed for the 40/50 four-wheel brake system.
| Identifier | WestWitteringFiles\K\December1923\ Scan28 | |
| Date | 1st December 1923 | |
| TO BY.{R.W. Bailey - Chief Engineer} FROM DA.{Bernard Day - Chassis Design} ORIGINAL DA{Bernard Day - Chassis Design}1/M20. 12. 23. c. to CJ. RG.{Mr Rowledge} HS.{Lord Ernest Hives - Chair} 40/50 - FOUR WHEEL BRAKES. X9940 We send herewith N.sch.1720. This shews four separate experiments on the front wheel brakes which we should like to try separately and perhaps altogether if found desirable. (1) Flexible steel shoes on the lines of the 40/50 back brakes. We believe that you can cut the experimental shoes out of the solid. We do not wish dies to be ordered until the experiment has been tried and some idea of its usefulness obtained. The shoes as shewn are proportional in depth to the back brakes. If they are found to be too stiff the rib may be reduced in depth or thickness and if this is not effective in securing jaggers then the rib might be sawn through in a series of places to make the shoe very flexible. We hope however that the flexible shoe will adapt itself to the drum wherever the latter takes up its position, and the result will be the elimination of jaggers and a shoe identical in design with the present 40/50 back wheel brakes. (2) We should like to study the brake wheel carrier to test if the jaggers are produced by distortion of the carrier due to it not taking a pure torque from the brakes. The pillars suggested as running from the pivot to the brake carrier lie very nearly in the line of load due to an unbalanced torque and we think should make a difference. If this flexibility has anything to do with the jaggers. The scheme shewn is suitable for existing pivots. If found to be successful we should probably alter the pivot forgings to produce a more effective result still for future cars. (3) The third experiment is to obtain this stiffness by increasing the gauge of the brake carrier and we have shewn this part made of .176 material on the lower part of the cross section. It will probably be necessary to machine the thickness away where the carrier bolts on to the pivot and also the outer flange might be reduced to the old thickness by machining as it would appear to be unnecessarily heavy in the new gauge. This leaves the increased thickness on the bent portions only. We do not expect that this modification is likely to be as effective as the pillars. It would however be a simpler alteration, but should only be tried if the pillars themselves shew an improvement. (4) The fourth experiment is stiffening up the drum by fitting a ribbed aluminium ring to the outside. This experiment would tend to demonstrate whether the jaggers were due to distortion of the drum or to the distortion of the carrier. DA.{Bernard Day - Chassis Design} | ||