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).
Instruction concluding that for a 28-slot armature in a standard carcase, the B angle must be 9.5 degrees.
| Identifier | ExFiles\Box 68\4\ scan0016 | |
| Date | 29th June 1920 | |
| 22 239 (100 BKS.) (SH57. 29-6-20.) MP 224358 ROLLS-ROYCE LTD. INSTRUCTIONS. To_________________________________19 Order No. PC 141 (2) Customer's No.___________________ All the curves are sharply controlled and for this reason we think that, although the peaks of two of the curves (B angles about 9.5°) are higher than what we consider safe for the WB{Mr Brazier/Mr Bell} machine, they are not dangerously high. On the other hand, to lower these peaks by further reducing the B angle from 9.5° would make curves like (2) much too low. Thus we conclude that for suitable use of this armature (28 slot) in a standard carcase the B angle must be 9.5°. Signed C.A.P. This Sheet must be filed on completion of the work. | ||