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).
Two faults with floating servo-cams on 25 HP and Bentley models, with a request for design alterations.
| Identifier | ExFiles\Box 105\4\ scan0173 | |
| Date | 3rd July 1935 | |
| To RHC.{R. H. Coverley - Production Engineer} c. to Hs{Lord Ernest Hives - Chair}/Std. KSH Hs{Lord Ernest Hives - Chair}/PJH.19/KW.3.7.35. Servo-Cams for 25 HP. and Bentley. The floating servo cams fitted to 5-B-IV on its last test in France have shown up two faults. The first is that the balls between the levers have made depressions in the levers in positions corresponding to the off position of the brakes. We think that this is because the cams do not come against their stop when the balls are at the bottom of the inclines so that the cams have some rotational play and can chatter. The second fault is that the ball thrust bearings on the cams do not provide sufficient sideways location and allow the cams to bear on the shaft. This is due to a mistake on Hs.{Lord Ernest Hives - Chair}1631, on which the radius of the ball grooves was specified as 0.175" for a 0.125" radius ball. The radius of the ball track need not be more than 0.130". Will you please alter the detail drawings to eliminate these faults and construct a corrected set of cams for 21-G-IV so that they can follow the car out. The cam angle should be 35°. Hs{Lord Ernest Hives - Chair}/P.J.Hardy. | ||