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).
Brake and servo modifications for B.V cars to protect against snow, water, and oil ingress.
| Identifier | ExFiles\Box 98\3\ scan0107 | |
| Date | 14th January 1941 | |
| BRAKE MODIFICATIONS TO B.V CARS IN CUSTOMERS' HANDS 1. PROTECTION AGAINST SNOW AND WATER. The diametrical clearances of all pins in levers and the sideways clearances of all levers in jaws are to be 0.005". All pins and servo plate levers to be chromium plated 0.0005" thick. Two concentric shields should be fitted to the servo to stop water from entering at the centre of the spring plate. One shield is formed by sweating a thin strip of tin (26 or 28 S.W.G. if possible) 0.200" wide round the 4.100" dia-meter corrugation in the outside of the spring plate. The other shield also has a width of 0.200" with a diameter of 3.800" and is made by sweating a strip of tin round the outside of a washer having an outside diameter of 3.800" and an inside diameter of 2.750". There are four holes of 0.201" diameter in the washer on a P.C. diameter of 3.100", to take the four countersunk-head 2BA screws which hold the shield on the gearbox under the servo oil seal housing. To save sweating the outer shield to the spring plate, a small number of spring plates have been made with an extra deep 4.100" diameter corrugation spun in. The inner shield will be made from a pressing when sufficient numbers are required. The drawings of these parts are not yet finished. 2. OIL IN SERVO. To prevent oil from entering the servo, some ½" or ⅝" linen tape should be soaked in neoprene latex and stuck round the outside of the spring plate. Neoprene is now un-available so, as a substitute, we use a rubber solution containing graphite and called "1480", which can be obtained from the British Tyre & Rubber Co., via the writer. The tape is first thoroughly soaked and then given a few minutes to dry before sticking. The servo should not be handled the tape has completely dried, the process taking 2 or 3 hours if no heat is applied. No mention has been made of judder, which is not a frequent fault on production B.V's, and it is felt that it would be best first to obtain a cure suitable for production, which will be decided upon after some experiments on 3-B-50 chassis 14.1.41. Rm{William Robotham - Chief Engineer}/MHR.{M. H. Rigby} | ||