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).
New automatic brake adjustment system and recommending its trial on the Spectre model.
| Identifier | ExFiles\Box 120\3\ scan0179 | |
| Date | 16th October 1935 | |
| X1029 To E.{Mr Elliott - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} c. to Da.{Bernard Day - Chassis Design} c. to Hy.{Tom Haldenby - Plant Engineer} c. to Rdy. c. to By/KW. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}7/KW.16.10.35. Automatic Brake Adjustment. On a recent visit to Ferodo we were able to see the automatic brake adjustment used by the Birmingham 'Bus Co. We attach a sketch showing how it is incorporated in the brake shoes. All former automatic adjustments we have seen suffer from one fault that prohibits their use. This is that if it is desired to maintain the clearance say between .025" and .050", then when the clearance reaches .050" it is suddenly taken up .025", thereby returning to the original setting. At the bottom of a long hill the clearance might easily become .075" due to drum expansion. .050" would be taken up and when the drums cooled, no clearance would exist. This new method is so arranged that every time the shoe moves an amount of the desired clearance, say .025", the clearance is taken up 3/100 of .001" by the worm and screw reduction. At the end of a long descent the clearance would only be reduced 6/100 x .001". Over-correction will therefore not take place. Also, owing to the adjustment being affected by "letting out the toggles", the cam and all the levers in the layout remain in their original position and variations in overall ratio do not occur through foreshortening of levers. We recommend trying such a scheme on SpectreCodename for Phantom III where the rear adjustment is none too accessible. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} | ||