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).
Results of switchbox contact life tests and requesting modifications for further testing.
| Identifier | ExFiles\Box 65\2\ scan0014 | |
| Date | 8th November 1928 | |
| To RHC.{R. H. Coverley - Production Engineer} from EFC. EFC3/T8.11.28. SWITCHBOX CONTACT LIFE TESTS. Herewith we hand to you (in parts) a switchbox upon which we are making contact life tests. We have completed a life test with this switchbox in a standard condition, i.e. breaking the field circuit first and the armature second. We wish to try in turn all the four possible combinations of the two cases above with the two cases of cutout shunt coil connected to dynamo terminals B. and C. respectively, finally to prove by actual test which is the best arrangement of the four. Although this only involves two arrangements of the switchbox it may involve three replacements of contacts if these become destroyed. For the second case, therefore will you please re-fit this switchbox with a new dynamo field contact so arranged that we still break the field first by an amount (similar to the present amount) of .070" in the blade movement. Subsequently for the later test we shall require you to reverse this order and time lag of breaking between the field and the armature contacts. EFC. | ||