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 test procedures for a relay switch, including a table of gap measurements and tolerances.
| Identifier | ExFiles\Box 64\3\ scan0217 | |
| Date | 9th March 1926 guessed | |
| -4- Contd. SECTION III. RELAY SWITCH. (1) Check over the various gaps which should be in accordance with the following table:- Position. Gap at Gap between Gap at Gap at upper pole core & lower carbon contact. armature. contact. contacts. Off. O .042"+8 .053"+10 -.040"+10 -6 -5 (depression) Carbons .018"+5 .025"±10 .021"±15 O just making. -3 On. .030"+5 .012"±3 O .027"±20 -3 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. (2) The fine wire coil shall be connected to the terminals of a six volt battery and the current taken at 6 volts at atmospheric temperature shall lie between 2.0 and 2.2 amperes. Contd. | ||