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).
Comparison of brush pressures on Goshawk, R. Bosch, and Scintilla dynamos.
| Identifier | ExFiles\Box 50\5\ Scan198 | |
| Date | 6th November 1918 | |
| RR 238 (300 Bks.) (SF 152. 6-11-18.) MP 197880 ROLLS-ROYCE LIMITED. INSTRUCTIONS. To Order No Customer's No. 3 19 The pressure per square inch with the specified springs, on the Goshawk dynamos, would be 4.85 lbs on the main brushes and 6.7 lbs on the control brush. The R Bosch dynamo, has very soft graphite brushes, with which a pressure of 4.25 lbs/sq" is used, in the initial position falling to less than half this amount when the brushes are worn. The Scintilla dynamo, which has very similar brushes to the R Bosch, is arranged with only 2.0 lbs/sq" brush pressure, which falls to 1.3 lbs with brush wear. Signed A.{Mr Adams} J.{Mr Johnson W.M.} Allen This Sheet must be filed on completion of the work. | ||