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 and measurements for battery ignition tungsten contact points.
| Identifier | ExFiles\Box 35\6\ scan 226 | |
| Date | 5th January 1927 | |
| X2894 TO EFC. FROM RHC.{R. H. Coverley - Production Engineer} RHC{R. H. Coverley - Production Engineer}1/BE.5.1.27. BATTERY IGNITION TUNGSTEN CONTACT POINTS X.2894 Herewith please receive contact points which have been ground flat in accordance with your instructions. Regarding the gauge you sent along, this is 3.875 radii which would give a dome on the two different diameter points of .0018 and .00073. We do not understand how the drawings have been made to the 1.407 radius, as we were under the impression you agreed to that on gauge attached. T P 3.875" rad gives .00099 and .00073 3.875" dia gives .00198 and .00146. RHC.{R. H. Coverley - Production Engineer} 1.407" rad gives .0027 and .0020 [Signature] | ||