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).
Proposals for alterations to the Peregrine Brake System to improve braking and reduce servo work.
| Identifier | ExFiles\Box 1\10\ B001_X106 TO X 110-page014 | |
| Date | 9th November 1932 | |
| 8156 R.{Sir Henry Royce} From Ha/Gry.{Shadwell Grylls} c. to Mr. c. to W.R. c. to L. c. to Da.{Bernard Day - Chassis Design} c. to Ry. c. to H-W. Ha/Gry.{Shadwell Grylls}2/Ha.9.11.32. PEREGRINE BRAKES. ----------------- We are sending you our proposals for alterations to the Peregrine Brake System to get better brakes and give the servo less work. This we propose doing in two ways, first by increasing the diameter of the servo about 15% together with running it slower by the use of a one start worm and secondly by altering the brake levers to obtain more direct bracking. Our idea has been to have the same period between adjustments as on the 20/25. The rear brake area on Peregrine is 130 sq.in./ton against 86 for the 20/25. We can therefore increase the direct bracking in this ratio. We must make sure that the brake pedal reaches the floorboards before the servo hits its stop. Due to the small scissor lever on Peregrine its angular movement for a given movement of the brake shoe is 1.2 times more than on 20/25. We suggest altering the ratio of servo to direct bracking in this ratio. Assuming we want 45% front bracking we get the following results:- Brake Units. ------------ 20/25 377 direct + 221S to rear + 304 S to front. Pere= { (At Present 220 direct + 193 S to rear + 301 S to front { (Proposed 550 " + 220 S to rear + 470 S to front S = Servo Multiplication of Torque | ||