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).
Letter to Automotive Products Co. Ltd. requesting information on their 'Lockheed' brake systems.
Identifier | ExFiles\Box 120\2\ scan0002 | |
Date | 11th February 1936 | |
X.1027 Exptl. Dept. Hs{Lord Ernest Hives - Chair}/AFM.{Anthony F. Martindale}14/KW. 11th February, 1936. The Automotive Products Co.Ltd., Tachbrook Road, Leamington Spa. "Lockheed" Brakes. Dear Sirs, We should be much obliged if you would provide us with certain information concerning your brake system. We are interested in the system in which each of the two shoes in a brake drum is an "unwrapping" shoe, and each is actuated by a separate hydraulic cylinder. What bore would such cylinders have, to exert a maximum force of 4,000 lbs., the normal maximum working load being 1,500 lbs., and what would be their external dimensions ? What is your system of brake adjustment in this scheme ? If each of these two cylinders was fed by a separate flexible pipe, what would be the minimum bore of the pipe, and what maximum pressure would it withstand ? Would armouring the flexes prolong their life ? We have in mind a brake linkage system in which each of two master cylinders operates three brake actuating cylinders. The reason for this is to provide us with a very considerable safety factor, in that total hydraulic failure would leave us with direct braking to the rear wheels, while failure of one of the two independent hydraulic systems would leave us with the braking force unimpaired or reduced slightly, as we may choose hereafter. Have you a master cylinder which would feed these other cylinders, and give a pressure ratio of about 6 ? This low ratio is very important indeed. Travel of piston would not exceed 2". | ||