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).
Ignition systems, governors, and horn mechanisms, comparing competitor designs.
| Identifier | ExFiles\Box 27\2\ Scan395 | |
| Date | 28th October 1935 guessed | |
| (3) spring carried the ignition current without losing temper, some loss of maximum revs was at first experienced due to this cause. The moving contact point is carried by a leaf spring with a second leaf superimposed on it. These leaves are secured to the contact arm, together with the spring, by a suitable screw passing through from one side to the other. The leaf spring point mounting is Messrs. Lucas' new method of providing a certain amount of contact scrub which we know is essential for continuous reliable operation, and it is claimed in this respect to be very effective. This new L.T. mechanism is used to run the high speed coil. I think it would be useful to obtain one of these latest Lucas ignition outfits and run it on the bench for comparison with our own type developed for Phantom 3. Ignition Governor. A new design of ignition governor has been developed based on the American Delco but with certain improvements, including the introduction of toggling connecting links which inhibit the effect of torque reaction from the breaker cam at low speeds. ---- In the brief time available I saw a number of other interesting points of less particular interest to ourselves. A very neat little mechanism for multiplying the crank angle to give 180° screen wipe, the means of matching the wind tone and other horns by means of a Neon tube stroboscopic apparatus in which it is seen that the tone note is only nine cycles different on approximately 300 between the matched horns, and also some interesting analytical curves of horn notes showing the vibration of the disc which supplies the noise energy of the alto horn superimposed on the lower periodicity of the operating mechanism. Oliver Lucas was unaware in connection with the wind tone horns of the difficulty of obtaining a loud note superimposed on the soft one. This is something that we must have irrespective of whatever scheme of operation is employed, and Lucas have agreed to make the necessary modifications for it. E.{Mr Elliott - Chief Engineer} | ||