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).
Graph of make ratio versus speed curves for an R Standard contact breaker, tested with standard and increased rated springs at various gap settings.
| Identifier | WestWitteringFiles\Q\2April1927-June1927\ 19 | |
| Date | 31th March 1927 | |
| MAKE RATIO .1 .2 .3 .4 .5 .6 .7 SPEED (r.p.m.) 400 600 800 1000 1200 1400 1600 1800 NORMAL RUNNING SPEED 700 r.p.m. .010" GAP .018" GAP .024" GAP MAKE RATIO - SPEED CURVES OF R STANDARD CONTACT BREAKER WITH STANDARD AND INCREASED RATED SPRINGS. STD. SPRING (LOAD ON POINTS .91 LBS) STRONGER SPRING (LOAD ON POINTS 1.4 LBS) REW 30-3-27 F.P.C. 31/3/27 | ||