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).
Explaining why a new, lighter type of front brake axle is more prone to squeaking and the proposed solution.
| Identifier | WestWitteringFiles\P\October1926-November1926\ Scan077 | |
| Date | 25th October 1926 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/GWH{George W. Hancock - Head Chateauroux} c. to BJ. Wor.{Arthur Wormald - General Works Manager}✓ c. to RG.{Mr Rowledge}✓ E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer}✓ ORIGINAL Hs{Lord Ernest Hives - Chair}/GWH{George W. Hancock - Head Chateauroux}/LG25.10.26. WHY THE NEW TYPE FRONT BRAKES FITTED TO X7420 AXLE G.74294 ARE MORE PRONE TO SQUEAK THAN THE PRESENT STANDARD. X8420 This is due to the general lightening all round of the brake unit. The drums are .010" lighter in section which makes them more flexible and causes more wear to take place on the toe of the shoes. The braking surface is 5.8% less which causes more distortion of the brake drum. The anchor plates are considerably lighter. We found that the inner anchor plate G.74257 distorts outwards when the brakes are applied. This plate is not supported between the cam bearing and top of pivot boss. To overcome this we fitted a bolt with a distance piece between the two anchor plates as near the cam bearing as possible which has stiffened up the plate and prevents the distortion. We have notified the D.O. of what has been done so as to get the improvement standardised. Hs{Lord Ernest Hives - Chair}/G.W.Hancock. | ||