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).
The bench endurance test of a new design brake stop lamp switch, detailing a failure and suggesting improvements.
| Identifier | ExFiles\Box 168a\2\ img123 | |
| Date | 4th January 1934 | |
| 6029 E.{Mr Elliott - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/Wst. c. to Sg.{Arthur F. Sidgreaves - MD} S: to Agr. Hs{Lord Ernest Hives - Chair}/Wst.O/MA.4.1.34. H.R. BRAKE STOP LAMP SWITCH. We have completed a bench endurance test on the new design R.S. switch to R.R.sch.449. The test consisted of operating the switch by a cam mechanism at regular intervals with the switch connected up to a 12 volt 36 watt lamp bulb, this being the proposed lamp bulb to be adopted on the new lucas stop lamp. The switch was operated for 150,000 times this being the estimated usage of the switch in certain conditions for 10,000 miles on a fast car. No failure of the switch was experienced and at the conclusion of the test it was dismantled for inspection. It was noted that one of the contact fingers had worn appreciably and where both of the contacts left the contact maker in the rest position the Bakelite insulation had burnt into a small cavity. We consider the switch to be a big improvement over the Butler switch previously fitted to our chassis. An improvement we suggest for your consideration in order to overcome the burning of the Bakelite, would be to make the two contacts laminated and allow them to spring off and on to the contact maker direct instead of rubbing on to the Bakelite. We have experienced similar trouble where contacts carrying current rub from a metal surface to a bakelite one, in the case of the Court headlamp changeover switch we used to fit on the early Phantom II Chassis. Hs{Lord Ernest Hives - Chair}/Wst. Mods RR incl 580 | ||