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).
Specification table for various gap measurements of a relay switch.
| Identifier | ExFiles\Box 70\4\ scan0152 | |
| Date | 9th March 1926 | |
| Contd. -4- EFC/T9.3.26. SECTION III. RELAY SWITCH. (1) Check over the various gaps which should be in accordance with the following table :- Position. Gap at upper contact. Gap between pole core & armature. Gap at lower contact. Gap at carbon contacts. Off. O .042"+8 -6 .053"+10 -5 .040"+10 (depression.) Carbons just making. .018"+5 -3 .025"+10 .021"+15 O On. .030"+5 -3 .012"+3 O .027"+20 N.B. The various limits on this table are arranged on the supposition that :- (a) The gap between the pole core and the armature, with the switch in the "on" position, (b) The upper contact gap with the switch in the "on" position, (c) The upper contact gap with the carbons just in contact, with their respective limits, are first fixed. | ||