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).
Description of the servo-assisted braking system, detailing its proportional operation and the advantages of the plate-type servo.
| Identifier | ExFiles\Box 73\3\ scan0154 | |
| Date | 8th July 1924 | |
| - 3 - Hs{Lord Ernest Hives - Chair}5/LG8.7.24. the road, it is difficult to remember when going backwards there is only approximately one-sixth the braking as when the car is going in the forward direction. The braking is proportioned so that under maximum brak- ing conditions the rear wheels will lock first. Immediately this happens, the servo stops rotating and it is impossible to get any extra braking on the front by additional pressure on the foot pedal. This lessens the possibility of front wheel skids on a greasy road. With other systems where the direct braking goes to all four wheels, even though the rear wheels are locked, additional pressure can be put on the front to lock the front wheels. The front brakes on the R.R. system being entirely servo operated, there is no loss of pedal movement in taking up the front brake clearance. There is also no feeling of springiness on the brake pedal due to the flexibility of the front brake mounting and operating mechanism. The type of servo employed is the plate type. It is specially designed so that it will always be free from oil and be capable of getting rid of heat generated. The plate type has been proved to be very much more consistent and reliable than the usual brake type of servo. Tests have shewn that the servo will run up to 20,000 miles without any attention or adjustments. | ||