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).
Causes of brake squeaks and the development of pivoted and loco type brake shoes.
| Identifier | WestWitteringFiles\V\March1931-September1931\ Scan147 | |
| Date | 23th April 1931 | |
| HS.{Lord Ernest Hives - Chair} E.{Mr Elliott - Chief Engineer}) FROM R.{Sir Henry Royce} DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer}) (At Le CanadelHenry Royce's French residence.) Copy to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} ORIGINAL R2/M23.4.31. 87360 / 85360 BRAKE SQUEAKS. I had the impression that we had standardised the pivoted tip to all brakes. We had done much work on the above in the way of dampers on the outside of the drums which evidently did some good but were not a cure. Mr. Hancock found, with others, that bedding of the shoes had great influence, and schemed his flexible tip which I concluded was not quite suitable for production, and I believe in common with all other devices has not proved a complete cure. Mr. Elliott and I thought the pivoted type of shoe would do what GWH.{George W. Hancock - Head Chateauroux} wanted in a way which actually saved money because of less bedding, then also the tip was pivoted which I agree could be used to go on with. I have since got DA.{Bernard Day - Chassis Design} to draw one or two other types of pivoted shoe with a view to more consistent brakes with far less work of bedding and much greater life. This was done because brakes became less effective at times and were thought hardly up to present duty compared with some of the fast cars, so we have tried to make our smaller size brakes equal others of larger dimensions, so saving cost and also cost of serious changes in dimensions and permanent increase in weight. There was at this later period great improvement to the drums which had been made too thin and flexible because they were thought to get over some troubles, which I now believe can be avoided with pivoted complete shoes, generally called by us loco type. Our brakes here have been very good indeed for squeaks and in all other respects the duty demanded of them is great, much pulling up for corners and traffic, and many sudden stops. They are fitted with the pivoted tip. I understand that HS.{Lord Ernest Hives - Chair} does not consider any scheme is perfect and has not done enough with the alternative type he has in the Expl. Dept. We were not expecting much improvement over the type mentioned above as regards squeaks, but they should require less fitting and should be more consistent as regards loss of braking, and also they should last longer because they wear all the shoe nearly equally, and so require no attention to bedding. (If they have these virtues they are worth gold, and are exactly what we want to maintain our reputation.) R.{Sir Henry Royce} 4 segment brake shoes to be tried GWH{George W. Hancock - Head Chateauroux} | ||