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 Messrs. New-Hudson Ltd. concerning the design of an anti-wrapping brake linkage and rear drum shoes.
| Identifier | ExFiles\Box 120\2\ scan0005 | |
| Date | 23th April 1936 | |
| X1029 Exptl. Dept. Hs{Lord Ernest Hives - Chair}/AFM.{Anthony F. Martindale}20/KW. 23rd April, 1936. Mr. Pratt, Messrs. New-Hudson Ltd., Icknield Street, Birmingham 18. Dear Sir, With reference to our discussion here on 20th April. In preparing the design of this scheme will you please arrange that the central lever of the anti-wrapping linkage between shoes shall rotate in the same direction as the drum (when the car is proceeding in a forward direction) while the brakes are being applied. The load in the two links will commonly be 550 lbs., and therefore the compression member must withstand 1,000 lbs. at least without buckling. We suggest you arrange this strut so that it is as short as possible, and the tension members will then be long. This will give the best weight economy. These figures assume that the line of action of the strut is coincident with the expander line of action; as it will be nearer the pivots in practice you will make a suitable allowance for this increase of stress. As we have already stated, the rear drums will be very rigid, but if you decide that shoes the full width of our rear drum (which is meant for twin shoes) would be inconveniently wide and might give rise to squeaks, will you kindly arrange that the shoes shall be near the end plate of the drum, and not the carrier plate side. | ||