Modifications to the Wraith brake system to prevent brake drag and front brake thump.
| Identifier | ExFiles\Box 7\7\ X 606 Brakes-page090 | |
| Date | 10th November 1937 | |
| To Da. {Bernard Day - Chassis Design} from Rm {William Robotham - Chief Engineer} /AFM. {Anthony F. Martindale} c. to By. {R.W. Bailey - Chief Engineer} c. to Mx. {John H Maddocks - Chief Proving Officer} 606 Rm {William Robotham - Chief Engineer} /AFM. {Anthony F. Martindale} 1/AP.10.11.37. WRAITH BRAKES. We have had to increase the rear pull off springs on Wraith in order to make certain the brakes do not drag. (W.Sch.5117) Now the front brakes are pulled on by the servo long before the rear brakes come into operation; this has two disadvantages. 1) There is a bad front brake thump. 2) It is possible to drive the car at quite high speeds and use only the front brakes. These are already overworked. The value of the pull off springs, measured at the lower end of the servo balance arm, is now 16 -24 lbs. (the rating is rather high). To ensure that the front brakes do not come on first an additional 20 lb. low rating pull off spring is necessary at this point. This necessitates a spring of increased strength on the friction damper. We find the load necessary in the working position is 250 lbs. and a new spring should be drawn giving a range on each side of this (150 - 350 lbs.) Will you please prepare schemes showing these two springs. Rm {William Robotham - Chief Engineer} /AFM. {Anthony F. Martindale} | ||
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).