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).
Visit to Smiths of Cricklewood regarding failures of electric clocks and the development of new speedometers.
| Identifier | ExFiles\Box 164\1\ img143 | |
| Date | 28th January 1937 | |
| (Sab.) CAP Please note and return 6026 WHF To Hs.{Lord Ernest Hives - Chair} from Rm{William Robotham - Chief Engineer}/wst. c. to Sg.{Arthur F. Sidgreaves - MD} c. to M.{Mr Moon / Mr Moore} c. to Sy. c. to Gx. c. to RHC.{R. H. Coverley - Production Engineer} c. to Roy.{Sir Henry Royce} Rm{William Robotham - Chief Engineer}/wst.3/AP.28.1.37. We visited Messrs Smiths, Cricklewood, on Monday last and among other things, discussed the failures of electric clocks. We pointed out to them that we considered the arrange-ment of heat fuses on these clocks to be rather unsatisfactory, in that - (a) The operation of the fuse was very erratic. (b) If the fuse operates we could not expect customers to change it with the clock in position in view of its inaccessibility. They informed me that they themselves were anxious to get rid of this heat fuse and were already experimenting with a form of thermostatic control, which would break the circuit to the clock in the event of the contacts remaining 'on'. With reference to the complaints we have had recently, whilst a number of these have been due to faulty adjust-ment of the heat fuse, it was pointed out to me that in a number of cases the balance staff had been found broken, and this could only have occurred, in their opinion, through bad handling at these Works or in transit. A new clock is being developed by them operating on the French Jaeger principle, in which no control spring is used and a tiny impulse motor adjusted to operate on a certain frequency is substituted for the normal escapement. They hope to submit samples of this clock for our test in the near future and to be able to produce this clock cheaper than the "Empire" clock which we are now using. It is not anticipated that we shall have any further serious trouble with heat fuses, as in November they tightened up the assembly control and inspection at their Works. Speedometers. We discussed with the A.T. people the possibility of producing a new A.T. speedometer of less costly design and with a magnetic movement requiring less torque. The torque required to drive our present speedometer is very much in excess of that required to drive the A.C. or standard Smith type of speed-ometer, universally used on other cars. Consequently, the drive continued | ||