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).
Proposal outlining alterations to the Peregrine brake system to improve braking and reduce servo load.
| Identifier | ExFiles\Box 179b\2\ img068 | |
| Date | 9th November 1932 | |
| c.c. From Mr/Try. c. to Mr. c. to H.R. c. to E.{Mr Elliott - Chief Engineer} c. to Dk. c. to Ry. c. to HQ. X407 He/Try./A/4a.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 braking. Our idea has been to have the same period between adjustments as on the 20/25. The rear brake area on Peregrine is 133 sq.in./ton against - 88 for the 20/25. We can therefore increase the direct braking 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 braking in this ratio. Assuming we want 45% front braking we get the following results:- Brake Units. ---------- 20/25 377 direct + 220S to rear + 304 S to front. Peree- { (at Present 220 direct + 193 S to rear + 301 S to front { (Proposed 550 " + 220 S to rear + 420 S to front S = Servo Multiplication of Torque | ||