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 discussing improvements to Bendix brakes, proposing an experimental test for harder carbon steel brake drums.
| Identifier | ExFiles\Box 120\1\ scan0019 | |
| Date | 13th October 1927 | |
| RECEIVED [Handwritten]: f8420 X4612 OY5.R.101327 October 13th, 1927. MR. F.H. Royce, Rolls-Royce Ltd., London, England. (Copy for attention of Mr. R.W.H. Bailey) " " " Mr. E.W. Hives) Dear Mr. Royce: RE: - BRAKES Mr. Allen reports as follows on a recent visit to the Lincoln plant. "They did have considerable trouble with the Bendix brake, but this has been entirely overcome and they are now quite satisfied with the equipment. The older brakes would grab because of the brake lining not being laid smooth, and, the brake drums, which were comparatively soft, roughening up. "The brake drums are now made of .75 - .85 carbon steel, machined all over, quenched in a Gleason quenching machine to a brinell hardness of 500 and then finally ground on the braking surface. The drum is really a fine job and is, if anything, better than our own. The brake band assembly is also ground to size so that a smooth, one hundred percent contact is obtained. They now believe the brakes are good." We submit that the suggestion of using a high carbon steel for the brake drums and heat treating to a hardness of 500 brinell, is worthy of consideration. We have not been able to prove that this is due to drums which are below the drawing limit of hardness and believe it is rather due to operation in districts where dirt roads are usual. We propose that the suggestion of harder brake drums should be given an experimental test. Yours very truly, [Signature] Maurice Olley MO/R | ||