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).
Specifications and adjustments for a combined main switch and relay switch unit.
| Identifier | ExFiles\Box 64\3\ scan0182 | |
| Date | 30th October 1924 | |
| X8650 To RHC.{R. H. Coverley - Production Engineer} from EFC. EFC3/T30.10.24. X.8650. COMBINED MAIN SWITCH & RELAY SWITCH UNIT. Herewith we return to you the above unit. To make this in accordance with our present version of the Specification of production inspection, adjustment and test, it is necessary, on the main switch unit to :- (1) Re-arrange the stops limiting the main lever in its 'out' position in such a way that the main lever is initially .030 to .035" closer to the core. (These stops are of course this amount too high owing to the insertion of the packing piece under the core). (2) It is estimated that the various gaps will then all be according to the following table:- Position of switch. Core to armature stop. Copper gap. Carbon gap. Off. .068 +3 -2 .080+5 -3 .102 +8 -8 Carbons just in contact. .029 + 6 -5 .015+10 -7 O Coppers just in contact. .020" O O In adjustinh the relation of copper to carbon gaps, it should be noted that the carbon gap stop on the main lever may foul the top carbon block securing piece. This gap could be definitely remedied by cutting away a little bit of this securing piece. (3) To reduce the effective strength of the main lever control spring. It is considered that the difference between this and how it was previously is due to the flexible conductors bearing upon the inside surface of this spring and therefore may be remedied by boring [handwritten above 'drawing' which is handwritten and struck through] the holes in one end of the flexible conductors, and thus making clearance between the conductors and the main spring. [handwritten] Contd. | ||