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 considerations for the Goshawk II's carburettor, axles, petrol gauge, and electrical system.
| Identifier | WestWitteringFiles\F\April1921\ Scan21 | |
| Date | 13th April 1921 | |
| To HS.{Lord Ernest Hives - Chair} & DA.{Bernard Day - Chassis Design} from E.{Mr Elliott - Chief Engineer} -3- (10) "GOSHAWK II" CARBURETTOR CONTROL. The "Goshawk II" carburettor control is arranged so that the pilot jet opens first and is fully open at half stroke of the hand control. The main butterfly throttle begins to open at half stroke. Mr. Royce points out that we never use all the quadrant on the 40/50 H.P. chassis. He would like the quadrant of "Goshawk II" to deal with two-thirds of the full movement of the carburettor throttle and so obtain fine adjustment for slow running. The slow speed jet choke will be operated by a separate fitting on the instrument board. (11) "GOSHAWK II" BACK AXLE. The 26 and 24 miles an hour at 1,000 back axle should be cancelled, in accordance with Mr. Royce's instructions, and axles of 20, and 22 M.P.H. should be prepared. This is on account of the heavy bodies which "Goshawk II" will have to carry. (12) "GOSHAWK II" FRONT AXLE. Re front axle for disc wheels, Mr. Royce does not want vertical pivots if the overhang on the wheel bearings is pronounced but would prefer to adopt a middle course of some inclination. (13) "GOSHAWK II" PETROL GAUGE. Here again we are handicapped because we have to carry a complete wheel. The gauge must have the float in the centre and the Indicator at the side. The scheme for this as proposed by Mr. Royce was described. It consists of a simple cheap float mechanism swinging through an angle of about 45 degrees around a horizontal axis and moving a vertical shaft by means of a 3" lever connected to a 2" lever with a wire link through an angle of about 60 degrees. The vertical shaft is near one end of the tank where it can be conveniently seen, and operates a magnetic instrument in which the hidden magnet is driven by an epicyclic multiplying gear of cheap construction having a ratio of about 4 to 1 which multiplies the movement of the vertical shaft from 60 to 240 degrees. It is intended that the float should be of cork. These cork floats when copper plated do not seem to have been a great success owing to faults in the coating. Mr. Hives stated that there is a varnish which will resist petrol or benzol, possibly of celluloid or shellac and recommended its adoption. This varnish should be tested. (14) "GOSHAWK II" ELECTRICAL SYSTEM. x4338 x3915 x4081. For operating the starter motor Mr. Royce wishes to use the central pedal carried on the dash mechanically connected to a switch on the motor itself. There should be a distribution board for the electrical system, but only one switch box. The cut-out should be put on the dynamo to save wiring, and for the lights a controller or barrel type of switch should be used because it is easy to lock this in any one position. Use also the same form of switch for the ignition. (Contd.) | ||