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).
Letter discussing cost-saving design changes for a distributor and contact breaker.
| Identifier | ExFiles\Box 37\1\ scan 106 | |
| Date | 25th May 1921 | |
| X. 3199. RECEIVED Hs{Lord Ernest Hives - Chair} JUN 14 Oy2 - G 25521 May 25, 1921 Mr. Claude Johnson, Managing Director, Rolls-Royce Ltd., London, England. Attention: Mr. F.H.Royce. Dear Sir:- Re: Distributor and Contact Breaker COPY I have written on May 19th re. the cost of parts for our distributor, and included some recommendations made by the molding concern, the Alden-Napier Co. for the cheapening of production of these parts through small changes of design. I wish to suggest, however, that the distributor and contact breaker could be cheapened still more without, I think, detracting from its performance, by making the head in one piece along the lines followed in the typical form of American battery ignition. 1.) HEAD: This implies the use of a single head with seven vertical bosses, containing the H.T. connections (brass inserts molded in place). Each of the six distributing inserts has a wire driven or sweated into it projecting downwards to below the path of the rotor, and each pin is bent or set to give a minimum air gap between itself and the distributing conductor on the rotor. These pins are generally brass, but might be nickel or platinum. If nickel, they should be at least as satisfactory as a spark plug point, and actually due to the less heat of the tiny spark at this point, even brass wire will run a long time without trouble in the dry climate of the U.S. The central contact can have a brass tube holding a carbon brush and spring to make contact with the rotor. The distributor head is spigotted in the timer case, and located circularly by a "blank-spot" on the spigot which fits in a milled slot in the timer case. | ||