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).
Specifications for dynamos, starter motors, and switches for the 40/50 chassis.
| Identifier | ExFiles\Box 51\2\ Scan042 | |
| Date | 10th November 1921 | |
| BY {R.W. Bailey - Chief Engineer} /C8/P10.11.21. contd. - 2 - for the switch boxes supplied to us on the 40/50 chassis. 3 C.A.V. Type D.B. Dynamos, of the single field winding, similar to sample machine supplied to us in accordance with our drawing number D.50204, blueprint of which was sent to Messrs. C.A.V. in connection with the first dynamo ordered. These should be supplied as insulated machines, as we can quite readily earth one of the terminals to the carcase at our own convenience 3 C.A.V. 4½" S.C. Starter Motors, similar to sample machine supplied to us, but should be arranged with one terminal earthed to the carcase, so as to be suitable for our earthed wiring system. The Armature shafts, Driving End Brackets, Bearing Plates and Pinions, will be provided by R.R. in the same way as we did for the first motor, but in the case of these three machines we have made some alterations to the end bearing brackets, as per drawing No. D.50253 DC. blueprint of which we enclose, from which it will be seen that the bracket is secured to the carcase by eight 3 BA. fitted studs instead of six 2 BA. This will enable C.A.V. to decrease the outside diameter of the car-case to 4.500" which we believe is their standard. In addition the depth of the spigot has been increased from .150" to .200". Messrs. C.A.V. should confirm that they can arrange the starter Motors in question to suit these alterations and that the deeper spigot will not foul the field winding. We also enclose blueprint of D.50466 showing outline arrangement of the starter Motor complete with Driving Shafts. We also wish to order the following switches etc., from Messrs. C.A.V. but before a definite order is placed a sample of what they propose to supply us should be submitted for approval:- 3 C.A.V. Starter Motor Switches, suitable for the above Starter Motors, contd. | ||