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).
Test report and design critique of a new petrol pump switch from Messrs. Lucas which failed endurance testing.
| Identifier | ExFiles\Box 168a\2\ img321 | |
| Date | 26th May 1937 | |
| To Sg.{Arthur F. Sidgreaves - MD} Hs.{Lord Ernest Hives - Chair} from Rm{William Robotham - Chief Engineer}/Wet. c. to WAG. c. to E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} Rm{William Robotham - Chief Engineer}/Tst.4/BJ.26.5.37. Petrol Pump Switch. We recently received from By.{R.W. Bailey - Chief Engineer} a new type petrol pump switch which had been manufactured by Messrs. Lucas in accordance with By's suggestions. After examining the switch it was subjected to our specification test and failed after 4,500 operations, due to the main spring fracturing. Our specification calls for an endurance test of 10,000 operations without failure and the switch is, therefore, unsatisfactory in this respect. It should be noted that the existing modified petrol pump switch now passes this specification quite easily and we have done as many as 25,000 operations without failure. Our criticisms of this new switch from a design point of view are - (1) The cams controlling the contacts are not keyed to the central spindle, and if any shrinkage occurs in the bakelite the whole assembly will easily work loose. (2) We should prefer a little more scrub on the contacts. (3) The spring load being at one end with an unsupported bearing causes a big load on the single plain bearing of the switch. We have returned the switch to By.{R.W. Bailey - Chief Engineer} for his attention. Rm{William Robotham - Chief Engineer}/Wet. | ||