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).
Design and potential faults of a push-button switch.
| Identifier | ExFiles\Box 34\3\ Scan060 | |
| Date | 15th April 1920 | |
| from BY.{R.W. Bailey - Chief Engineer} c. EFC. x 2644 BY5-P15.4.20. PUSH BUTTON SWITCH. ------------------- Referring to your memo EP{G. Eric Platford - Chief Quality Engineer}20/P13420, we do not consider there is any likelihood of the above switches giving trouble in service, as it is impossible to bring foot pressure on/the switch itself. In the early days, after you had experienced some little trouble with the original design, we modified the design of the switch in such a manner that the foot pressure is only applied between the push button and the boss of same acting as a stop and that the pressure which actuates the switch cannot exceed the spring pressures by which the switch itself is returned to its original position. We rather fancy that you have overlooked the fact that full foot pressure does not reach the moving parts of the switch itself but only a question of the few ounces necessary to depress the switch. If you will return to me any switches which are earthing as suggested, I will take the matter up with the department concerned, as I consider that it shows there was not sufficient clearance in the first place, although I must say we have made elaborate arrangements to prevent this occurring. BY.{R.W. Bailey - Chief Engineer} | ||