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).
Inspection and setup instructions for a main switch unit, detailing clearances and contact gaps.
| Identifier | ExFiles\Box 60\2\ Scan053 | |
| Date | 25th February 1932 guessed | |
| contd. -2- (6) Inspect generally the small Eureka wire bobbin resistance which is connected in parallel with the main switch operating coil. (7) The arrangement of the lower hold on contact spring on the auxiliary switch shall be such that the set is approximately zero when, the spring is just touching the lower spring contact stop i.e. the condition when the lower contacts are broken. (8) It should be verified that there is not more than .004" clearance between the main switch armature and main support when the former is fully depressed to the armature stop. II. MAIN SWITCH. (1) The various gaps of this unit should be checked over and confirmed to agree with the gaps and limits given on the sheet herewith. The main switch table of gaps is made up on the assumption that the following gaps are first fixed. (a) Air gap at core centre- switch full on .010-.2 (b) Core to armature stop when first coppers are just in contact. .045 (c) Copper gap when carbons are just in contact. .040 (d) Carbon gap, switch in fully off position. .025+.5 (2) The coil of the main switch shall be connected contd. | ||