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).
The performance and modifications of the brake layout for the Peregrine II car.
| Identifier | ExFiles\Box 1\10\ B001_X106 TO X 110-page025 | |
| Date | 10th December 1932 | |
| X106. R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} c.c. to Sg.{Arthur F. Sidgreaves - MD} c.c. to Nor. c.c. to E.{Mr Elliott - Chief Engineer} c.c. to Hy.{Tom Haldenby - Plant Engineer} c.c. to Ds. c.c. to Hdy.{William Hardy} Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}2/MA.10.12.32. PEREGRINE BRAKES. The attached sketch shows the arrangement of the brake layout tried out on 3. Peregrine II car. The brakes proved to be very effective requiring only a light pedal pressure. The brake clearances were set at .015 at the shoe centre. This was in order to reduce as much as possible lost movement at the brake pedal and servo. The set up of the pilot shoes was reduced from .02" to .007 considerably reducing the sponginess of the system. The amount of direct braking was increased from that shown on the M.scheme to the same as both the 40/50 and 20/25. The amount of front braking was also greatly increased, both by altered leverages and the use of a 40º servo cam. The total brake units for a given pedal pressure were therefore higher than we have previously had on any car. The amount of wear of the linings measurable after a run of 650 miles including the worst hills in Devon and North Wales was .0015 at the front shoe centres and nothing on the rear brakes, and hence nothing at the brake pedal. The toggles in the brake drum between the cam and the shoes were found to be buckled after the run. We are stiffening these and also the rear brake cam shafts and the shafts in the front axles. The sponginess in the system should then be very small. Coupled with the increased stroke of the larger servo we should be able to run with the amount of braking tried on this car without the necessity of frequent adjustment, or the possibility of the servo reaching the end of its travel, which on this car it was very near to doing. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} | ||