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).
Improvements and concerns for vehicle braking and steering systems.
Identifier | ExFiles\Box 30\6\ Scan130 | |
Date | 1st November 1923 guessed | |
(2) BRAKES TO DEFINITELY WIND OFF. You will notice inmy 3rd. telegram that by inverting the levers and using a vertical push rod we ought to get a definite release of the brake pressure with the deflection of the front springs by the brakes. We believe that this feature is going to be of the utmost importance because it will probably steady the action of the brakes and render them much safer, and perhaps be a means of limiting their maximum application. FERODO OR OTHER MATERIAL. Regarding the material of the friction surfaces you know that the ferodo has not given entire satisfaction. I am not sure whether we must expect this, or whether we can test some other material of the same nature or even test (to improve our knowledge) the use of metal surfaced shoes such as cast iron or copper. STEERING. Regarding the pivot angles I think there is no doubt that we must chance steering wobbles by leaning these sufficiently that they shall not become vertical even with this greatest pressure it is possible to put on the pedal (possibly limited by the pedal reaching the floorboards). You will notice that we have now a straight steering tube with which it is not intended to use spring buffers. It is therefore possible that this steering would work quite satisfactorily, though a little heavier by non-reversible plain thrust washers, in which case the steering would be very much safer. Kindly test this. BEDDING OF SHOES. Referring to the unequal work performed by the 2 brake shoes we think this is simply a question of equality of bearing. We fear however that no matter how well bedded it is possible that with a hard application of the brakes, they may perform and bed slightly different to a light application. If this is a fact this feature will be difficult to avoid. SELF WRAPPING BRAKES. Regarding the self wrapping brakes such as is being schemed by Perrot to make the application easy by the foot only, that is each brake shoe has its own 'servo', I think this scheme would prove dangerous because one feels as if the co-efficient of friction varying in each brake drum would tend to make the brakes still more unequal with the same operating pull. R.{Sir Henry Royce} | ||