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).
Memo discussing an investigation into brake squeaks and the failure of a pilot shoe spring design.
| Identifier | ExFiles\Box 102\6\ scan0183 | |
| Date | 28th May 1937 | |
| To Rm{William Robotham - Chief Engineer} Bentley Brakes Kingbus May 28th 37 MARTINDALE Any comments Rosette We have been going into Rosette squeaks here. An investigation of the pilot shoe load has proved that it is hopeless with the design it is hard to hope to get any results. The supposed spring fitted under the pilot shoe might as well be thrown away for what good it is. Whoever designed this spring had not the slightest knowledge of what it was for or its action. The load factor is (average 1.2lbs per .001") the dia of the (spring) is 5/16" in a full 3/8" hole in the shoe. On two brake shoes just checked the load on the pilot shoe was 120 lbs. you just might as well make the brakes solid as have these condition. It was never designed in the first place to have loads of this kind. We are as Kingbus | ||