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).
Decisions on impulse starters versus hand magnetos for armoured cars, and the design of a suitable tyre air pump.
| Identifier | Morton\M5\ img005 | |
| Date | 8th October 1920 | |
| X.4195 Contd. Extract 7 E1/G8.10.20. ARMOURED CARS. X.4195. Impulse Starter versus Hand Magneto. Regarding the above point Mr. Royce stated that the War Department could have whichever they liked, but that he advised the hand magneto. He thought our policy should be to demonstrate starting by each method to them on a car, and then, placing our advice before them, let them decide. The hand magneto is what we have used for a long time on aero work, and it does not interfere with the reliability of the main magneto. It was decided that Mr. Royce's advice should in all cases be definitely communicated to the persons responsible for departure from our standard practice. AIR PUMP FOR TYRES. X.4197. The question of fitting an efficient tyre pump is somewhat complicated by the contract conditions for the armoured cars, which specify that deliveries of chassis should be effected in two months, but not necessarily completed with all special fittings. Mr. Royce decided that we ought to make a special effort to provide an efficient pump and drive to our own designs. The pump was to be of the single cylinder type carried on a plate from the fan anchorage with space left for a flywheel on the rear end, and a simple form of spring drive on the front, end, if it was found that the uneven torque of the pump caused snatch in the chain. The drive was to be effected by a pinion on the magneto driving shaft, driving a gear wheel carried on a housing able to rotate round the magneto drive centre for chain adjustments, the gear wheel driving the pump by means of an ordinary roller chain. By sliding the pinion on the magneto driving shaft the whole device could be stopped. X.943. All the details of a suitable air pump were gone into, comprising crank with bearing each side, auto delivery valve, and mechanically operated inlet, all arranged, to be well lubricated and suitable for a speed of, say, 400 revs. It would run about engine speed while pumping, and when engine was running faster than 400 would be disconnected. Oil fil ter designs were discussed and decided upon, and Kellog specimen of tyre pump examined and condemned by all. The arrangement decided upon seemed so promising that the fitting will probably be capable of adoption promising-that-the-fitting by anyone specially desiring such a fitting on any 40/50 HP. chassis. Contd. | ||