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).
Secret memo detailing design changes to the RRM Brake System, specifically thread angles and lever dimensions.
| Identifier | WestWitteringFiles\L\Jan1924-March1924\ Scan124 | |
| Date | 1st March 1924 | |
| TO BY.{R.W. Bailey - Chief Engineer} & HS.{Lord Ernest Hives - Chair} FROM DA.{Bernard Day - Chassis Design} ORIGINAL DA{Bernard Day - Chassis Design}1/M27. 3. 24. S E C R E T. E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. 79940 RRM. BRAKE SYSTEM. Referring to N.scheme 1769., the thread in the screw was intended to be 45°. We did not instruct it as we intended Mr. Stent to send you full particulars of this operating gear. Will you now please make the levers on the pressure screw gear 2.625 instead of 1.8 as shewn, and drop the thread to 30°. 2.625 is the longest lever that can be got in without fouling the change speed shaft. On the agreed scheme the lever can-not be more than about 2" long, and ought to be less. In this case the thread should be made 30° also. DA.{Bernard Day - Chassis Design} | ||