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 for the production, inspection, and testing of a push duplex button switch.
| Identifier | ExFiles\Box 64\4\ scan0309 | |
| Date | 28th June 1929 | |
| (VERSION 2.) X7655 28.6.29. X.7655. PUSH DUPLEX BUTTON SWITCH. X.7781. SPECIFICATION OF PRODUCTION INSPECTION AND TEST. (1) Inspection shall be made that :- (a) The carbon contacts exactly bed together at the point of breaking, and that both pairs of contacts make contact simultaneously when depressed by a force applied to the centre of top contact plate. Also that the carbons are not cracked or chipped. (b) The cylindrical metal contacts are making correct line contact centrally and that both pairs make contact simultaneously. (c) The flexible connections to the carbon contacts exhibit no signs of fraying. Also that these top carbon contacts move quite freely in the top plate when lifted against the springs. (d) The relative rating of the top carbon leaf springs and the spiral springs under the bottom carbons, shall be such that no movement of the bottom carbons occurs during complete depression of the switch. (e) The motion of the button exhibits no sign of friction in the main cover when operated separately with switch mechanism removed. (2) The button depression and contact gaps shall now be ascertained, and should be in accordance with the following table :- contd. | ||