Issues and proposed adjustments for the Phantom II braking system.
| Identifier | ExFiles\Box 12\5\ 05-page141 | |
| Date | 5th November 1929 | |
| x7360 To EP. {G. Eric Platford - Chief Quality Engineer} from Hs {Lord Ernest Hives - Chair} /Rm. {William Robotham - Chief Engineer} c. By. {R.W. Bailey - Chief Engineer} c. Da. {Bernard Day - Chassis Design} c. Wor. {Arthur Wormald - General Works Manager} c. MX. {John H Maddocks - Chief Proving Officer} HS {Lord Ernest Hives - Chair} /Rm {William Robotham - Chief Engineer} 5/AD5.11.29. PHANTOM II. BRAKES. With reference to your EP {G. Eric Platford - Chief Quality Engineer} 5/H24.10.29. (1) Rear Brake actuating lever and movement. We cannot understand the necessity of working to 1.5" at the axle brake actuating lever. We are running a number of experimental cars with .5" movement at the end of this lever and are having no trouble. We think .7" movement is adequate for all conditions in a new car and recommend that this should be worked to, for cars leaving test. (2) There is some impression that the geometry of the rear axle necessitates additional clearance being allowed in the rear brakes. Actually if the brake ropes are arranged to allow the rear axle actuating levers to come up against their stops with the car in its normally loaded position, i.e. 4.25 buffer clearance, every way the axle moves the brake ropes will be released slightly. This release only amounts to .1" from the maximum bump to 10" buffer clearance, as will be seen by the attached curve. We think this is negligible. With 12" buffer clearance the brake ropes are slacked off to .2" which we think is a negligible amount considering the rarity of this condition. (3) Notches Adjustment. There is a prevailing impression that the adjustment on Phantom II is coarser than on Phantom I. Actually on Phantom II one notch adjustment equals .019 at the shoe centre, on Phantom I .022 at the shoe centre. We agree however, that there is some difficulty in getting the required adjustment. This is due to the direct braking leverage and not to the adjustment provided. We have taken up the question with Mr. Royce. We are going into the whole question of brake leverages, but the outstanding feature is that apparently twice the necessary clearance is being given to the brake shoes in the new condition. We think if this is altered matters will be at once improved considerabl | ||
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).