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).
Technical memo discussing the testing and development of J.III type shock dampers.
| Identifier | ExFiles\Box 105\3\ scan0264 | |
| Date | 20th July 1932 | |
| 85520. Rdy. From Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} c. HY.{Tom Haldenby - Plant Engineer} Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} 3/MA. 20.7.32. SHOCK DAMPERS J.III TYPE. We send you indicator diagrams of the J.III valve made with the pressure piston as requested. They differ from the original diagrams, which we did not send you, because we found that during our first tests the piston was sticking. The damper is perfectly quiet under these conditions. It will be noticed that the maximum pressure falls off with speed on the High Pressure side. We have carried out your suggestions re improving the venting of the damper, to establish with certainty whether or not air in the system is causing the valve to flutter. So far improved venting has not made much difference. In considering R's note R.1/M.18.7.32., he apparently thinks that the vertical type damper was quiet due to getting the air away. If you will look up our note Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson}5/KT.1.6.31., to Da.{Bernard Day - Chassis Design} you will find the whole history of the double damper outlined and will note that every form of venting, even to putting two non-return ball valves in the piston, was unsucc-essful in silencing the valve until we fitted it with a mask and drilled it. We think that this rather disposes of air as the nigger in the job. The other point is that we do not know that the vertical piston type of damper would have been silent on the road even with the masked valve as we did not get any tests. We are pushing on with your other suggestions as quickly as possible. With regard to your queries re the additional cost of the latest 25HP dampers referred to in Sg.{Arthur F. Sidgreaves - MD}6/E.{Mr Elliott - Chief Engineer} 13.7.32. | ||