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).
Required revisions and improvements for the Bentley III brake system.
| Identifier | ExFiles\Box 98\3\ scan0026 | |
| Date | 11th May 1938 | |
| 406 Da.{Bernard Day - Chassis Design} from Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} c. By.{R.W. Bailey - Chief Engineer} c. HPS.{Horace Percy Smith - Experimental Factory Mgr} Rm{William Robotham - Chief Engineer}/AFM{Anthony F. Martindale}6/R.11.5.38. BENTLEY III BRAKES. Several points need attention on this brake system:- (1) The front equalizer FB.3130 has failed in torsion on 7.B.V. The action necessary here is - (a) The re-designed equalizer drawings need altering to make stiffer. (b) The equalizer now being machined for B.50 should be held up. (c) A special stiff equalizer in aluminium bronze for 7.B.V. should be instructed by the D.O. (2) The brackets FB.3552/3 which carry the idler levers on the front pan flex every time the brakes are applied, and we feel that we cannot take the risk of a failure due to fatigue on the brake system. These idler levers should not be carried on cantilever pins: a second bracket is necessary on each side. (3) Without any reason whatsoever we use both .250" dia. rods and .3125" dia. rods for B.III brakes. In the case of the rods joining on to the servo equalizer, one rod is .250" dia. and the other .3125" dia. and yet the load in them is equal. The entire system should be revised and .3125" dia. rods and threads used throughout as this is our standard, and we must not depart from it. (The Jaguar uses .3125" dia rods throughout.) (4) We find we can use an oil dash pot on the front brakes of B.III in place of the friction damper and rubber buffer on the servo linkage. No thumps and no clicks on release occur. The friction damper and rubber buffer are very awkward to design into the new servo. We suggest the oil dash pot, bijur fed, is used. The dash pot has an equal leak each way, and no valves. Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} | ||